Water treatment plant operation volume 2 7th edition answer key

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Water Treatment Plant Operation Volume 2. A Field

Study Training Program. Revised.

California State Univ., Sacramento. School o£

Engineering.; National Environmental Training

Association, Valparaiso, IN.

California State Dept. of Health Services,

Sacramento. Sanitary Engineering Branch.;

Environmental Protection Agency, Washington, DC.

Office of Drinking Water.

T-901361-01-0

690p.; Some charts and drawings may not reproduce
well. Pages containing final examination and answers
are printed on dark grey paper and maybe
illegible .

Mr. Ken Kerri, California State

University-Sacramento, 6000 J Street, Sacramento, CA
95819-2654.

Guides - Classroom Use - Guides (For Teachers) (052)
— Guides - Classroom Use - Materials (For Learner)
(051) — Tests/Evrluation Instruments (160)

MF04/PC28 Plus Postage.

Chemical Analysis; *Course Content; ^Drinking Water;
^Environmental Education; Fluoridation; *Home Study;
Laboratory Procedures; Postsecondary Education;
Safety; Training Methods; *Water Quality; *Water
Treatment

ABSTRACT

The purpose of this water treatment field study
training program is to: (1) develop new qualified water treatment
plant operators; (2) expand the abilities of existing operators,
permitting better service both to employers and public; and (3)
prepare operators for civil service and certification examinations
(examinations administered by state/professional associations which
operators take to indicate a level of professional competence).
Voliune 2 is a continuation of voliune 1, in which the emphasis was on
the knowledge and skills needed by operators of conventional surface
water treatment plants. This 12-chapter volume contains information
on: iron and manganese control; fluoridation; softening;
trihalomethanes; demineralization; handling and disposal of processed
wastes; maintenance; instrumentation; safety; advanced laboratory
procedures; drinking v^ater regulations; and administration.
Objectives, glossary, lessons, questions (with suggested answers),
and a test are provided for each chapter. A final examination (with
answers), how to solve water treatment plant arithmetic problems,
water abbreviations, complete glossary, and subject index are
provided in an appendix. Information on objectives, scope, and uses
of this manual and instructions to participants in home-study courses
are found in volume 1. (TW)

ERIC

Environmental Protection Agency Review Notice

This training manual has been reviewed by the Office of Drinking Water,
U.S. Environmental P -^♦'^^tion Agency and the California Department of
Health Services. Both agencies have approved this manual for publication.
Approval does not signify that the contents necessarily reflect the views
and policies of the Environmental Protection Agency nor the California
Department of Health Services. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use by
the Environmental Protection Agency; California Department of Health
Services; California State University, Sacramento; National Environmental
Training Association; authors of the chapters or project reviewers, consul-
tants, and directors.

WATER TREATMENT PLANT OPERATION

Volume II
A Field Study Training Program

prepared by

California State University, Sacramento

School of Engineering
Applied Research and Design Center

in cooperation with the
National Environmental Training Association

Kenneth D. Kern, Project Director

for the

California Department of Health Services
Sanitary Engineering Branch
Standard Agreement #80-64652
and

U.S. Environmental Protection Agency
Office of Drinking Water
Grant No. T-901 361 -01-0

1988

ERIC

OPERATOR TRAINING MANUALS

OPERATOR TRAINING MANUALS IN THIS SERIES are available from Ken
Karri, California State University, Sacramento, 6000 J Street, Sacramento, CA
95819-2654, phone (916) 278-6142.

1. WATER TREATMENT PLANT OPERATION, 2 Volumes,

2. SMALL WATER SYSTEM OPERATION AND MAINTENANCE,

3. WATER DISTRIBUTION SYSTEM OPERATION AND MAINTENANCE.

4. OPERATION OF WASTEWATER TREATMENT PLANTS, 2 Volumes,

5. ADVANCED WASTE TREATMENT,

6. INDUSTRIAL WASTE TREATMENT,

7. TREATMENT OF METAL WASTESTREAMS,

8. PRETREATMENT FACILITY INSPECTION, AND

9. OPERATION AND MAINTENANCE OF WASTEWATER COLLECTION
SYSTEMS, 2 Volumes.

NOTICE

This manual is revised and updated before each printing based on comments
from persons using the manual.

First printing, 1983 7,000
Second printing, 1988 5,000

PREFACE

VOLUME II

Volume II IS a continuation of Volume I. In Volume I. the emphasis was on the knowledge and skills needed by
operators of cor /entional surface water treatment plants. Volume II stresses information needed by those
operators but also includes information on specialized water treatment processes for i^-on and manganese
control, fluoridation, softening, trihalomethanes. demineralization and the handling and disposal of process
wastes. Topics of importance to the operators of all water treatment plants include maintenance, instrumenta-
tion, safety, advanced laboratory procedures, water quality regulations, administration, and how to solve water
treatment plant arithmetic problems.

You may wish to concentrate your studies on those chapters that apply to your water treatment plant. Upon
successful completion of this entire volume, you will have gained a broad and comprehensive knowledge of the
entire water treatment field.

For information on:

1. Objectives of this manual,

2. Scope of this manual,

3. Uses of this manual,

4. Instructions to participants in the home-study course, and

5. Summary of procedure.

please refer to Volume I.

The Project Director is indebted to the many operators and other persons who contributed to this manual.
Every effort was made to acknowledge material from the many excellent references in the water treatment field.
Reviewers Leonard Ainsworth, Jack Rossum, and Joe Monscvitz deserve special recognition for their extremely
thorough review and helpful suggestions. John Trax. Chet Pauls, and Ken Hay. Office of Drinking Water, U.S. En-
vironmental Protection Agency, and John Gaston. Bill MacPherson, Bert Ellsworth, Clarence Young, Ted Bakker,
and Beverlie Vandre. Sanitary Engineering Branch. Californici Department of Health Services, ail performed
outstanding jobs as resource persons, consultants and advisors. Larry Hannah served as Education Consultant.
Illustrations were drawn by Martin Garrity. Charlene Arora helped type the field test and final manuscript for print-
ing. Special thanks are well deserved by the Program Administrator. Gay Kornweibel, v/ho typed, administered
the field test, managed the office, administered the budget, and did everything else that had to be done to com-
plete this project successfully.

KENNE-^H D. KERRI
PROJECT DIRECTOR

ERIC

TECHNICAL CONSULTANTS

John Brady
Gerald Davidson
Larry Hannah

Jim Sequeira
Susuma Kawamura
Mike Young

NATIONAL ENVIRONMENTAL TRAINING ASSOCIATION REVIEWERS

George Kinias, Project Coordinator
E. E. "Skeet" Arasmith Andrew Holtan William Redman

Terry Engelhardt
Dempsey Hall
Jerry HIggins

Deborah Horton
Kirk Laflin
Rich Metcalf

Kenneth Walimaa
Anthony Zigment

PROJECT REVIEWERS

Leonard Ainsworth
Ted Bakker
Jo Boyd
Dean Chausee
Walter Cockrell
Fred Fahlen
David Fitch
Richard Haberman
Lee Harry
Jerry Hayes
Ed Henley
Charles Jeffs

Chet Latif
Frank Lewis
Perry Libby
D. Mackay
William Maguire
Nancy McTlgue
Joe Monscvitz
Angela Moore
Harold Mowry
Theron Palmer
Eugene Parham
Catherine Perman

David Rexing
Jack Rossum
William Ruff
Gerald Samuel
Carl Schwing
David Sorenson
Russell Sutphen
Robert Wentzel
James Wright
Mike Yee
Clarence Young

ERIC

COURSE OUTLINE

WATER TREATMENT PLANT OPERATION, VOLUME

1 . The Water Treatment Plant Operator
by Ken Kern

2. Water Sources and Treatment
by Bert Ellsworth

3. Reservoir Management and Intake Structures
by Dick Barnett

4. Coagulation and Flocculatlon
by Jim Beard

5. Sedimentation
by Jim Beard

6. Filtration

by Jim Beard

7. Disinfection

by Tom Ikesaki

8. Corrosion Control
by Jack Rossum

Page
1

15
39
91
143
195
247
333

9. Taste and Odor Control
by Russ Bowen

10. Plant Operation
by Jim Beard

11. Laboratory Procedures
by Jim Sequeira

Appendix by Ken Kern

Final Examination

How to Solve Water Treatment
Plant Arithmetic Problems

Water Abbreviations

Water Words

Subject Index

Page
373

413

455

527
528

541
586
587
633

COURSE CyiLINE

WATER TREATMENT PLANT OPERATION. VOLUME II

Page

12. Iron and Manganese Control 1
by Jack Rossum

13. Fluoridation 25
by Harry Tracy

14. Softening 63
by Don Gibson and Marty Reynolds

1 5. Trihalomethanes 1 1 5
by Mike McQuIre

1 6. Dem ineralization 1 35
by Dave Argo

17. Handling and Disposal of Process Wastes 179
by George Uyeno

18. Maintenance 207
by Parker Robinson

19. Instrumentation 331
by Leonard Ainsworth

20. Safety

by Joe Monscvitz

21. Advanced Laboratory Procedures
by Jim Sequeira

22. Drinking Water Regulations
by Tim Gannon

23. Administration
by Tim Gannon

Appendix by Ken Kern

Final Examination

How to Solve Water Treatment
Plant Arithmetic Problems

Water Abbreviations

Water Words

Subject Index

Page
387

445

487

535

561
563
573

599
601
649

ERIC

CHAPTER 12

IRON AND MANGANESE CONTROL

Jack Rossum
with a special section by
Gerald Davidson

ERIC

2 Plant Operation

TABLE OF CONTENTS

Chap'^^r 12. Iron and Manganese Control

OBJECTIVES 3

GLOSSARY 4

12.0 Need to Control Iron and Manganese 5

12.1 Measurement of Iron and Manganese 5

12.10 Occurrence of Iron and Manganese 5

12.11 Collection of Iron and Manganese Samples 7

12.12 Analysis for Iron and Manganese 7

12.2 Remedial Action g

12.20 Alternate Source 9

1 2.21 Phosphate Treatment 9

12.22 Removal by Ion Exchange 11

12.23 Oxidation by Aeration 12

12.24 Oxidation with Chlorine 13

12.25 Oxida ion with Permanganate 13

12.26 Operation of Filters 14

12.27 Proprietary Processes by Bill Hoyer 14

12.28 Monitoring of Treated Water 15

12.29 Summary 15

12.3 Operation of an Iron and Manganese Removal Plant

by Gerald Davidson 1g

1 2.30 Description of Process 1 g

12.31 Description of the Plant 17

12.32 Operation of the Greensand Process 19

12.4 Maintenance of a Chemical Feeder 20

12.5 Troubleshooting Red Water Problems 21

12.6 Arithmetic Assignment 21

12.7 Additional Reading 2i

SUGGESTED ANSWERS

Chapter 12. IRON AND MANGANESE CONTROL

Answers to questions on page 6.

12.0A When clothes are washed in water containing iron
and manganese, they will come out stained. Iron
bacteria will cause thick slimes to form on the walls
of water mams. These slimes are rust colored from
iron and black from manganese. Variations in flow
cause these olimes to slough which results in dirty
water. Furthermore, these slimes will impart foul
tastes and odors to th water.

12. OB The growth of iron bacteria is easily controlled by
chlorination. However, when water containing iron is
chlorinateo, the iron is converted into rust particles
and manganese is converted into a jet black com-
pound, manganese dioxide.

12.0C The generally accepted limit for iron is 0.3 mg/L and
that for manganese is 0.05 vng/L

Answers to questions on page 7.

1«?.1A Iron and manganese react with dissolved oxygen or
chlorine to form insoluble compounds.

1 2.1 B Iron and manganese samples are acidified when they
are collected to prevent the formation of iron and
manganese scales on the walls of the sample bot-
tles.

ERLC

12. 1C Samples for iron and manganese testing should be
collected as close to the well or source of water as
possible.

Answers to questions on page 11.

12.2A If a well produces water containing dissolved oxygen
as well as iron and manganese, the iron and manga-
nese are probably coming from the lower aquifers.
Try to seal off the lower aquifers.

1 2 2B To determine if nearby wells contain iron and manga-
nese, samples could b^ collected and analyzed from
nearby private wells. Also, discussions with well
drillers who have been active in the locality and with
engineers with the state agency responsible for the
regulation of well drilling will be helpful.

12.2C Bench scale tests are a method of studying different
ways or chemical doses for treating water on a small
scale in a laboratory.

12 2D If polyphosphate solutions are much over 48 hours
old, they will react slowly with water to form ortho-
phosphates which are much less effective in p^-event-
ing manganese deposits.

Iron and Manganese 23

Answers to questions on page 16.

12 2E If water being treated for iron and manganese by ton
exchange contains any dissolved oxygen, the resin
becomes fouled with iron rust or insoluble manga-
nese dioxide.

12.2F The higher the pH. the faster the rate of oxidation of
iron to insoluble ferric hydroxide.

12.2G The purpose of the reaction basin is to allow time
for he oxidation reactions to take place. The aera-
tion process should produce sufficient dissolved
oxygon for the iron to be oxidi7ed to insoluble ferric
hydroxide.

12 2H Water can be dechlorinated by the use of reducing
agents such as sulfur dioxide (SO2), sodium bisulfite
(NaHSOg), and sodium sulfite (NagSOj) Bisulfite is
commonly used because it is cheaper and more
stable than sulfite.

12 21 To oxidize greensands used to oxidize iron and
man'ianese, backwash the greensands. After back-
washing, regenerate with potassium permanganate

Answers to questions on page 20.

12 3A The accepted limits for iron and manganese are 0.3
mg/L for iron and 0.05 mg/L for manganese.

12.3B In the first flocculator/clarifier, chlorine is added with
flash mixing and flocculatlon for 10 minutes. During
the next 1.9 hours, aeration occurs through fine
bubble diffusers. This process removes 95 percent
of the iron. The treated water then flows to the
second flocculator/clarifier and the water is injected
with potassium permanganate and sodium hydrox-
ide. This IS followed by flash mixing, 10 minutes of
flocculation and 1.9 hours of settling. After this
process, the water is passed through filters which
produce treated waters with 0.01 mg/i. of iron and
also 0.01 mg/L oi manganese.

12.3C Dilution water is added at the discharge of the
chemical feeder pump to prevent the crystalizatlon of
potassium permanganate which could cause failure
of the pump discharge piping

12.3D A greensand plant should be shut down when the
permanganate solution level in the vat gets low
because of the importance of the permanganate in
the process. Without permanganate the greensand
could lose its charge and iron and manganese will
enter the distribution system.

Answers to questions on page 21.

12.4A When a chemical feeder pumps hypochlorite, cal-
cium carbonate coatings may develop on the poppet
valves if the dilution water contains carbonate alka-
linity. Coated valves do not seal properly and the
feeder fails to pump the hypochlorite solution prop-
erly.

12.48 The problems caused by calcium carbonate scale on
a hypochlonnator s popoet valves can be solved in
two ways:

1. A hydrochloric acid solution can be pumped
through the system, or

2. The dilution water for the feeder can be obtained
from an ordinary home water softener.

Answers to questions on page 21.

12.5A Red or dirty water complaints may be caused by:

1. Iron and/or manganese in the water,

2. Corrosive waters, and

3. Iron bacteria in the distribution system.

12 58 Slime growths in distribution systems can be con-
trolled by maintaining a free chlorine residual
throughout the distribution system and by a distribu-
tion syslem flushing program.

OBJECTIVE TEST

Chapter 12. IRON AND MANGANESE CONTROL

Please write your name and mark the correct answer on
the answer sheet as directed at the end of Chapter 1. There
may be more than one correct answer to the mulitple choice
questions.

True-False

1. Iron and manganese must be removed from water due
to adverse health effects.

1. True

2. False

2. Iron and manganese are rarely found in groundwater.

1. True

2. False

3. Acidified samples for iron may produce high results if
clay particles are present.

1. True

2. False

4. If the water orcduced by a well contains dissolved
oxygen along with iron and manganese, this is an

indication that water is being drawn from only one
aquifer.

1. True

2. False

5. Chlorine should never be fed ahead of polyphosphate.

1. True

2. False

6. If the water to be treated contains dissolved oxygen,
both iron and manganese may be removed by ion
exchange using the same resins that are used for water
softening.

1. True

2. False

7. Oxidation of manganese by aeration is commonly used
on waters with high manganese concentrations.

1 True
2. False

ERLC

24 Plant Operation

8. Chlorine will oxidize manganese to insoluble manga-
nese dioxide.

1. True

2. False

9. Chlonne will oxidize iron to insoluble ferric hydroxide

1. True

2. False

10. Potassium permanganate oxidizes iron and manganese
to insoluble oxides in the same way as chlonne.

1. True

2. False

1 1 Greensand is capable of oxidizing both iron and manga-
nese and is also capable of filtration.

1. True

2. False

12. The flocculator/clarifiers are the most important pro-
cess in the greensand treatment plant.

1. True

2. False

13. The solution mixers in the solution vat must run continu-
ously to keep the potassium permanganate in solution

1. True

2. False

14. A residual of potassium permanganate must be present
in the filter effluent for the greensand media to be
effective.

1. True

2. False

15. Commercial sodium hypochlorite solutions (such as
Jhlorox) contain an excess of lime

1. True

2. False

Multiple Choice

16. Problems caused by iron ind manganese in water
include

1. Corrosion.

2. Dirty water.

3. Illness.

4. Stainec' laundry.

5. Tastes and odors.

17. Iron and manganese react with to form insoluble

compounds.

1. Alum

2. Chlorine

3. Dissolved oxygen

4. Ion exchange resins

5. Lime

18. Methods or equipment used to test for iron include

1. Amperometric.

2. Atomic af/soi ption.

3. Nessler tubes.

4. Phosphate.

5. Spectrophotometer.

19. The proper polyphosphate dose is the lowest dose tha*
delays noticeable discoloration for a period of at least

1. 4 hours.

2. 12 hours.

ERLC

3. 24 hours

4. 2 days.

5. 4 days.

20. Do not use polyphosphate solution much over

hours old.

1 3

2. 6

3. 12

4. 24
5 48

21 The rate of oxidation of iron to form insoluble ferric
hydroxide is decreased by inci eases in

1 . Carbon dioxide.

2. Lime dose.

3. Organic substances

4. pH.

5. Temperature.

22. Chemical doses being added to control iron and manga-
nese are inadequate if

1 . Addition of chlorine to the treated water produces a
brownish floe.

2. Analysis of treated water contains iron.
3 Consumers complain of black particles.

4. Consumers complain of pink water.

5. Consumers complain of rusty water.

23. The differences between greensand filters and conven-
tional filters include the

1 . Backwash rate is higher for greensand filters.

2. Backwash time should be decreased for greensand
filters.

3. Filtration rate is faster for greensand filters.

4. Greensand is coarser than conventional sand.

5. Greensand removes iron and manganese.

24. Determine the setting on a potassium permanganate
chemical feeder In pounds per day if the chemical dose
determined from a jar test is 2.5 mg/L and the flow is

0. 45 MGD.

1. 8.4 lbs/day

2 9.4 lbs/day

3. 10.4 lbs/day

4. 12.9 lbs/day

5. 22.5 lbs/day

25. Determine the setting on a potassium permanganate
chemical feeder in pounds per million gallons if the
chemical dose determined from a jar test is 2.5 mg/L

1. 21 Ibs/M Gal

2. 32 Ibs/M Gal

3. 43 Ibs/M Gal

4. 46 Ibs/M Gal

5. 50 Ibs/M Gal

26. A reaction basin 18 feet in diameter and 6 feet deep
treats a flow of 500,000 gallons per day. What is the
average detention time in minuies?

1 . 25 minutes

2. 28 minutes

3. 30 minutes

4. 33 minutes

5. 35 minutes

CHAPTER 13

FLUORIDATION

Harry Tracy

ERIC

26 Water Treatment

TABLE OF CONTENTS

Chapter 13. Fluoridation

OBJECTIVES

GLOSSARY

13.0 Importance of Fluoridation

13.1 Fluoridation Programs

13.2 Compounds Used to Furnish Fluoride Ion

13.3 Fluoridation Systems

13.30 Chemical Feeders

13.31 Saturators

13.32 Downflow Saturators

13.33 Upflow Saturators

13.34 Large Hydrofluosillcic Acid Systems

13.4 Final Checkup of Equipment

13.40 Avoid Overfeeding

13.41 Review of Designs and Specifications

13.5 Chemical Feeder Startup ^3

13.6 Chemical Feeder Operation ^

13.60 Fine Tuning ^

13.61 Preparation of Fluonde Solution ^

13.62 Fluoridation Log Sheets ^5

1 3.620 Hydrofluosillcic Acid ^

13.621 Sodium Sllicofluoride 4

13.7 Prevention of Ove^'feeding 4

13.8 Underfeeding ^

13.9 Shutting Down Chemical Systems 5

13.10 Maintenance 5

13.1 1 Safety In Handling Fluoride Compounds 5

13.110 Avoid Overexposure 5

13.111 Symptoms of Fluoride Poisoning 5

13.112 Basic First Aid 5

13.1 13 Protecting Yourself and Your Family 5

13.114 Training 5

13.12 Calculating Fluoride Dosages 5

13.13 Arithmetic Assignment 5

13.14 Additional Reading c

13.15 Acknowledgments 5

SUGGESTED ANSWERS

Chapter 13. FLUORIDATION

Answers to questions on page 29.

13.0A If a person dnnks water with an excessive amc jnt of
fluoride, the teeth become mottled (brown, chalky
deposits).

13.0B Children who drink a recommended dose of fluoride
have fewer dental caries (decay or cavities).

Answers to questions on page 30.

13 1 A The water department or water company makes the
final decisions as to types of fluoride chemicals and
feeding equipment to be used.

13.2A The three compounds most common'y used to fluori-
date water are hydrofluosillcic acid, sodium fluoride
and sodium silicofluoride.

Answers to questions on page 42.

13.3A Dnnking waters may contain fluoride ions by three
different types of situations:

1. Raw water source may have adequate or exces-
sive fluoride ions naturally present,

2. Two water sources may be blended together (one
higher and one lower than acceptable level) to
produce an acceptable level, and

3. Fluoride ions must be added to the water to
achieve an acceptable level

13.3B Fluoridation systems must incorporate means to
prevent both overfeeding and backsiphonage along
with means to monitor the amount of chemical used.

13.3C Hard water can produce problems in systems using
saturators and dissolving tanks through the forma-
tion of low solubility (deposits of) calcium and mag-
nesium fluoride compounds.

13.3D A saturator is a device which produces a *;uoride
solution for the fluoridation process. The device is
usually a cylindrical container with granular sodium
fluoride on the bottom. Water flows either upward or
downward through the sodium fluoride to produce
the fluoride solution.

Answers to questions on page 44.

13.4A Overfeeding of fluoridation chemicals must be pre-
vented to avoid illness and bad public relations.

13.4B The fluoridator should be sized to handle the full
range of both present and future doses or provisions
should Is made for future expansion.

13.5A When Inspecting the fluoridation electrical system,
inspect th e system for (1 ) proper voltage; (2) properly
sized overload protection; (3) proper operation of
control lights on control panel; (4) proper safety lock-
out switches and operation; and (5) proper equip-
ment rotation.

13.58 Safety equipment that should be available near a
fluoridation system include an eyewash, drench

showers, dust masks, face shields, gloves and vent
fans.

Answers to questions on page 48

13.6A Known Unknown

Flow. MGD = 6 MGD Feed Rate, gal/day

Cone Fluoride, mgfL = 1.2 mg/L
Hydrofluosillcic acid = 20%

1. Use Treatment Chart I, Hydrofluosilicic Acid. Start
at the left side with 6 MGD and move horizontally
to the right to the intersection of the 20% diagonal
line.

2. Drop down vertically to the chemical feed rate of
30 GALLONS PER DAY, for 1 mg/L fluoride appli-
cation.

3. Adjust the flow rate for a dose of 1.2 mg/L.

Flow Rate. ^ (Ftow Rate from Cnart. gal/dayKDestred Dose, mg/i.)

^(30 gal/dayKI 2 mg/L)

1 mgIL
^ 36 ga./day

13.6B Differences between the volume of acid used from a
storage tank and the volume actually fed into the
system could be caused by errors in readings, leaks
or equipment malfunctions.

Answers to questions on page 52.

137A Overfeeding shculd be prevented because no addi-
tional benefits result from overfeeding and there is a
waste of chemicals and money. Lxcessive overfeed-
ing could be harmful to consumers.

13.7B If significant overfeeding occurs, the plant should be
shut down. The affected mains should be flushed
and the local and state health departments notified.

13.8A A fluoridation operation could be shut down for
cleaning, adjustments or due to safety controls.

Answers to questions on page 54.

13.9A If fluoridation equipment is going to be shut down
for an extended length of tine, it should be cleaned
out to prevent corrosion and/or the solidifying of
the chemical. Lines and equipment could be da-
maged when started if chemicals left in them solidi-
fy.

13.1 OA Fluoride dust can be removed from gears by the
use of a vacuum cleaner.

13.1 OB To determine if the fluoridation equipment is provid-
ing the desired dosage, monitor the fluoride ion
concentration in the treated water.

13.11 A If you are acutely poisoned by a fluoride chemical,
you may be thirsty, vomit and have stomach
cramps, disrrhea, difficulty in speaking and dis-
turbed color vision.

ERLC

60 Water Treatment

OBJECTIVE TEST

Chapter 13. FLUORIDATION

Please write your name and mark the correct answers on
the answer sheet as directed at the end of Chapter 1 . There
may be more than one correct answer to the multiple choice
questions.

True-False

1 . Governing bodies usually rely upon a vote of the people
to decide the types of fluoride chemicals and feeding
equipment to be used.

1. True

2. False

2. Water should be analyzed for its natural fluonde level
before fluondation.

• True
2 False

3. Fluoridation cnemicals are harmful to consumers at high
levels.

1. True

2. False

4. Scale formation in chemical feed systems may be
prevented by ti.e use of polyphosphates instead of a
zeolite softener

1. True

2. False

5. A day tank usually stores sufficient chemical solution to
treat water for at least one day.

1. True

2. False

6. Chemical feed systems should allow the chemical feed
to vary with changing head cond:' ons.

1. True

2. False

7. Equipment may be damaged in minutes if it is run
without lubrication.

1. True

2. False

8. A positive displacement pump will damage itself or
rupture lines in seconds if allowed to run against a
clos'^d valve or system.

1. True

2. False

9. Fluoridation must be a continuous operation.

1. True

2. False

10. Operators could be seriously injured if they open a
chemical line that has not been properly flushed out.

1. True

2. False >^ ^

11. Hydrofluosilicic acid solutions can irntate your skin.

1. True

2. False

12 Never eat, drink or smoke in or around fluoridation
chemical storage o* feed areas.

1. True

2. False

13. Sanitary defects may develop in fluoridation systems.

1. True

2. False

14. Hydrofluosilicic acid must be washed off your skin
immediately.

1. True

2. False

15. Special safety training must be given to ail operators
who must handle fluoride compounds.

1. True

2. False

Multiple Choice

16. The Maximum Contaminant Level (MCL) for fluoride in

dnnking water ranges from mg/L, defjending

on the annual average . imum daily air temperatures.

1. 0.4 to 0.8

2. 0.9 to 1.3

3. 1.4 to 2.4

4. 2.5 to 3.5

5. 3.6 to 5.0

17. The compounds most commonly used to fluoridate
water include

1. Ammonium silicofluonde.

2. Calcium fluoride.

3. Hydrofluosilicic.

4. Silicofluonde.

5. Sodium fluoride.

18. Which o' the following items must be considered when
selecting a fluoridation chemical?

1. Costs

2. Ease of handling

3. Operator safety

4. Solubility of chemical in water

5. Storage requirements

19. Water with a hardness above

mg/L must be

ERIC

softened to prevent severe scaling of fluoridation equip-
ment.

1. 10

2. 25

3. 40

4. 55

5. 75

Fluoridation 61

20. Fluoridation chemicals that may be fed with a saturator
include

1. Granular calcium fluoride.

2. Granular sodium fluoride.

3. Hydrofluosilicic acid.

4. Powdered calcium fluoride.

5. Powdered sodium fluoride.

21- The responsibility of the chief ope-ator regarding fluori-
dation equipment includes

1. Design.

2. Functioning of equipment.

3. Maintenance.

4. Operation by plant personnel

5. Results from the process.

22. Fluoridation operations may be temporarily shut down
due to

1. Adjustments.

2. Calculating dosages.

3. Cleaning.

4. Maintaining storage area

5. Safety controls.

23 Which of the following items should be Included in your
checklist for shutting down a fluoridation chemical sys-
tem?

1. Clean the mix and feed tanks.

2. Drain the mix and feed tanks.

3. Fill the chemical hoppers.

4. Flush out all the solution lines.

5. Turn on the electncal power

24. A flow of 2 MGD is to be treated with an 18 percent
solution of hydrofluosilicic acid HjSiFg). The water to be
treated contains no fluoride and the desired fluoride
concentration is 1 ,2 mg/L. Assume the hydrofluosilicic
acid weighs 9 6 pounds per gallon. Calculate the hydro-
fluosilicic acid feed rate in gallons per day. Sele.t the
closest answer.

1. 12 GPD

2. 15 GPD

3. 30 GPD

4. 110 GPD

5. 300 GPD

25 A flow of 250 GPM is to be treated with a 2.4 percent
(0.2 pounds per r^allon) solution of sodium fluoride
(NaF). The water to be treated contains 0.3 mg/L of
fluoride ion and the desired fluoride ion concentration is
1.4 mg/L. Calculate the sodium fluoride feed rate in
gallons per day. Assume the sodium fluoride has a
fluoride purity of 43.4 percent. Select the closest an-
swer.

1. 1.1 gal/day

2. 2.2 gal/day

3. 3.3 gal/day

4. 25 gal/day

5. 38 gal/day

26. A flow of 0.8 MGD is treated with sodium silicofluoride
(NagSiFg) to provide a fluoride ion dose of 1.2 mg/L.
What Is the feed rate in pounds per day? Commercial
sodium fluoride has a punty of 98.5 percent and the
fluoride ion purity of sodium silicofluoride is 60.7 per-
cent. Select the closest answer.

1. 6.0 lbs/day

2. 8.0 lbs/day

3. 11.7 lbs/day

4. 13.4 lbs/day

5. 19.5 lbs/day

27. The feed solution from a saturator containing 1.8 per-
cent fluoride ion is used to treat a flow of 500,000
gallons per day. The desired dose is 1 2 mg/L of fluoride
ion and the raw water does not have any fluoride.
Calculate the feed rate in gallons per day of the satura-
tor solution. Select the closest answer.

1. 18.0 gal/day

2. 19.5 gal/day

3. 26.6 gal/day

4. 28.9 gal/day

5. 33.3 gal/day

ERIC

CHAPTER 14

SOFTENING

Don Gibson
and

Marty Reynolds

64 Water Treatment

TABLE OF CONTENTS

Chapter 14. Softening

Page

OBJECTIVES gg

GLOSSARY Qj

LIME-SODA ASH SOFTENING bv Don Gibson

Lesson 1

14.0 What Makes Water Hard? 70

14.1 Why Soften Water'? 71

14.2 Chemistry of Softening 72

14.20 Hardness 72

14.21 pH 73

14.22 Alkalinity 73

14.3 How Water Is Softened 75

14.30 Basic Methods of Softening 75

14.31 Chemical Reactions 75

14.310 Lime 7g

14.31 1 Removal of Carbon Dioxide 75

14.312 Removal of Carbonate Hardness 76

14.313 Removal of Noncarbonate Hardness 76

14.314 Stability 7g

14.315 Caustic Soda Scftening 77

14.316 Calculation of Chemical Dosages 77

14.32 Lime Softening 73

14.33 Split Treatment 7g

14.34 Lime-Soda Ash So' ting 81

14.35 Caustic Soda Softening 81

14.36 Handling, Application and Storage of Lime 82

14.4 Interactions with Coag- lants 82

14.5 Stability 83

14.6 Safety 84

14.7 Sludge Recirculation and Disposal 85

14.8 Records 85

EMC

Softening 65

14.9 Jar Tests 85

14.90 Typical Procedures 85

14 91 Examples 86

14.92 Calculation of Chemical Feeder Settings 86

iON EXCHANGE SOFTENING by Mai ^^ynolds

Lesson 2

14.10 Description ot Ion Exchange Softening Process 91

14.11 Operations 95

14.110 Service 95

14.111 Backwash 95

14.112 Brine 97

14.113 Rinse 97

14.12 Control Testing of Ion Exchange Softeners 97

14.13 Limitations Caused by Iron and Manganese 98

14.14 Disposal of Spent Brine 98

14.15 Maintenance 99

14.1C Troubleshooting 100

14.160 Test Units 100

14.161 Service Stage 100

14.162 Backwash Stage 100

14.163 Rinse Stage 100

14.164 Brine Injection Stage 100

14.17 Startup and Shutdown of Unit 101

14.18 Ion Exchange Arithmetic 101

14.19 Blending 105

14.20 Recordkeeping 106

14.21 Arithmetic Assignment 106

14.22 Additional Reading 106

14.23 Acknowledgments 107

Suggested Ansvi/ers 107

Objective Test Ill

66 Water Treatment

OBJECTIVES

Chapter 14. SOFTENING

Following completion of Chapter 14, you should be able

1. Explain what makes water hard and the advantages of
softening,

2. Describe the processes used to soften water,

3. Prepare chemical doses to soften water with consider-
ations given to coagulants and stability,

4. Safely handle softening chemicals,

5. Dispose of process sludges and brines,

6. Keep neat and accurate softening records,

7. Perform jar tests and apply results,

8. Operate and maintain chemical precipitation and ion
exchange softening processes,

9. Start up anc shut down water softening units, and

10. Blend softened waters with unsoftened waiters (split
treatment) for delivery to consumers.

to:

ERIC

Softening 67

GLOSSARY

Chapter 14. SOFTENING

ALKALINITY (AL-ka-LIN-it-tee) ALKALINITY

The capacity of water to neutralize acids. This capacity is caused by the water's content of carbonate, bicarbonate, hydroxide,
and occasionally borate, silicate, and phosphate. Alkalinity is expressed in milligrams per liter of equivalent calcium carbonate
Alkalinity is a measure of how much acid can be added to a liquid without causing a great change in pH.

ANION ,AN-EYE-on) ANION

A negatively charged ion in an electrolyte solution, attracted to the anode under the influence of a difference in electrical poten-
tial. Chloride (CI") is an anion.

CALCIUM CARBONATE EQUILIBRIUM CALCIUM CARBONATE EQUILIBRIUM

A water is considered stable when it is just saturated v/ith calcium carbonate. In this condition the water will neither dissolve nor
deposit calcium carbonate. Thus, in this water the calcium carbonate is m equilibrium with the hydrogen ion concentration

CALCIUM CARBONATE (CaCOj) EQUIVALENT CALCIUM CARBONATE (CaCOj) tvJUIVALENT

An expression of the concentration of specified constituents in water in ter.,is of their equivalent value ^o calcium carbonate.
For example, the hardness in water which is caused by calcium, magnesium and other ions is usually described as calcium car-
bonate equivalent.

CATION (CAT-EYE-on) CATION

A positively charged ion in an electrolyte solution, attracted to the cathode under the influence of a difference m electrical poten-
tial. Sodium ion (Na^) is a cation.

DIVALENT (die-VAY-lent) DIVALENT
Having a valence of two, such as the ferrous ion, Fe^\

EQUIVALENT WEIGHT EQUIVALENT WEIGHT

That weight which will react with, displace or is equivalent to one gram atom of hydrogen.

GREENSAND GREENSAND

A sand which looks like ordinary filter sand except that it is green in color This sand is a natural ion exchange mineral which is
capable of softening water and removing iron and manganese.

HARD WATER HARD WATER

Water having a high concentration of calcium and magnesium ions. A water may be considered hard if it has a hardness greater
than the typical hardness of water from the region. Some textbooks define hard water as water with a hardness of more than
100 mg/L as calcium carbonate.

HARDNESS, WATER HARDNESS. WATER

A characteristic of water caused mainly by the salts of calcium and magnesium, such as bicarbonate, carbonate, sulfate, chlo-
ride and nitrate. Excessive hardness in water is undesirable because it causes the formation of soap curds, increased use of
soap, deposition of scale in boilers, damage in some industrial processes, and sometimes causes objectionable tastes in drink-
ing water.

HYDRATPD LIME HYDRATED LIME

Limestone that has been "burned" and treated with water under controlled conditions until the calcium oxide portion has been
converted to calcium hydroxide {Ca(0H)2). Hydrated lime is quicklime combined with water. CaO + Hfi Ca(0H)2. Also see
QUICKLIME.

INSOLUBLE (in-SAWL-you-bull) INSOLUBLE
Somscning that cannot be dissolved.

ERIC

68 Water Treatment

'ON ,0N
An electrically charged atom, radical (such as SO^^ ), or molecule formed by the loss or gam of one or more electrons

ION EXCHANGE EXCHANGE
A water treatment process involving the reversible interchange (switching) of ions between the water being treated and the
solid resm. IJndestrable Ions in the water are switched with acceptable ions m the resin.

ION EXCHANGE RESIN ,0N EXCHANGE RESIN

Insoluble polymers, used in water treatment, that are capable of exchanging (switching or giving) acceptable cations or anion^
to the water being treated for less desirable ions

METHYL ORANGE ALKALINITY METHYL ORANGE ALKALINITY

A measure of the total alkalinity .n a water sample The alkalinity is measured by the amount of standard sulfuric acid required
to lower the pH of the water to a pH level of 4.5. as ind.cated by the change in color of methyl orange from orange to pink
Methyl orange alkalinity is expressed as milligrams per liter equivalent calcium carbonate.

NPDES PERMIT NPDES PERMIT

National Pollutant Discharge Elimination System permit Is the regulatory ac, jncy document designed to control all discharges of
pollutants from point sources In U.S. waterways. NPDES permits regulate discharges into navigable waters from all point
sources of pollution, including industries, municipal treatment plants, large agncultural feed lots and return irrigation flows.

PHENOLPHTHALEIN ALKALINITY (FEE-nol-THAY-leen) PHENOLPHTHALEIN ALKALINITY

The alkalinity in a water sample measured by the amount of standard acid required to lower the pH to a level of 8 3. as indicated
by the change in color of phenolphthalein from pink to clear. Phenolphthalein alkalinity is expressed as milliarams per liter
equivalent calcium carbonate.

PRECIPITATE (pre«SIP-uh-TATE) PRECIPITATE

(1) An insoluble, finely divided substance which is a product of a chemical reaction w-' in a liquid.

(2) The separation from solution of an insoluble substance.

QUICKLIME QUICKLIME
A material that is mostly calcium oxide (CaO) or calcium oxide in natural association with a lesser amount of magnesium oxide
Quicklime is capable of combining with water to form hydrated lime. Also see HYDRATED LIME.

RECARBONATION(re-CAR-bun-NAY-shun) RECARBONATION
A process in which carbon dioxide is bubbled into the water being treated to lower the pH. The pH may also be lowered by the
addition of acid Pecarbonation is the final stage in the lime-soda ash softening procerus. This process converts carbonate ions
to bicarbonate ions and stabilizes the solution against the precipitation of carbonate compounds.

RESINS RESINS
See ION EXCHANGE RESINS.

SATURATION SATURATION

The condition of a liquid (water) when it has taken into solution the maximum po&sible quantity of a given substance at a given
temperature and pressure.

SLAKE SLAKE
To mix with water with a true chemical combination (hydrolysis) taking place, such as in the slaking of lime.

Er|c 80

Softening 89

SLAKED LIME SLAKED LIME

See HYDRATED LIME.

SUPERSATURATED SUPERSATURATED

An unstable condition of a solution (water) m whicf i the solution contains a substance at a concentration greater than the satu-
ration concentration for the substance.

TITRATE (TIE-trate) TITRATE

To TITRATE a sample, a chemical solution of known strength is added on a drop-by-drop basis until a certain color change,
precipitate, or pH change in the sample is observed (end point). Titration is the process of ad jing the chemical reagent in incre-
ments until completion of the reaction as signaled by the end point.

81,

ERIC

70 Water Treatrent

CHAPTER 14 SOFTENING

jm6'Soda Ash Softening by Don Gibson

(Lesson 1 of 2 Lessons)

14.0 WHAT MAKES WATER HARD?^

Water hardness is a measure of the soap or detergent
consuming power of water. Technically hardness is caused
by DIVALENT^ nnetallic cations which are capable of reach-
ing (1) with soap (detergent) to form precipitates and (2) wim
certain anions present in water to form scale.

Cations Causing
Haro. 'ss

Calciufii, Ca^^
Magnesium. Mg^^
Strontium, Sr^^
li-on, Fe2^
Manganese, Mn^*

Most Common Anions

Bicarbonate, HCO3
Sulfate, SO/-
Chloride, Cr
Nitrate, NO3-
bilicate, SiOg^-

Ca'^^ium and magnesium are usually the only cations that are
presont In significant concentrations. Therefore, ^-ardnebd is
generally considered to be an expression of the total con-
centration of the calcium and magnesium ions that are
present in the water. However, if any of the other cations
listed are present in significant amounts, they should be
included in the hardness determination.

Table 14.1 descnbes various levels of hardness. Different
textbooks will use s'.-nilar classifications. Hardness levels in
source waters, local conditions, and local usage will influ-
ence consumers' attitudes towards the hardness of their
water.

TABLE 14.1 DESCRIPTION OF VARIOUS LEVELS OF
HARDNESS^

Description

1 . Extremely soft to soft

2. Soft to moderately hard

3. Moderately hard to hard

4. Hard to very hard

5. Very hard to excessively
hard

6. Too hard for ord:*^ary domestic
use

Hardness in Terms of
nig/L as Calcium
Carbonate

0-45

46-90

91-130
131-170
171-250

OVER 250

To help you understand this chapter on water softening,
some of the terms used are defirted below.

HARD WATER is a water havin^ a high concentration of
'^alcium and magnesit.n ions. A water ma; be considered
hird if •. has a hardness greater than the typical hardness of
water from the region. Some textbooks defiiie hard water ^^s
a water v^ith a hardness of more than 100 mg/L as ca'c' 71
carbonate.

• Portions of the material covered in the first three sections of this chapter were provided by Don Gibbon, f^arty Reynolds Susumu Ka^^^a-
mura, Teny Engelhardt, Jack Rossum and Mike Curry.

2 Divalent (dic-VA Y-lent). Having a valence of two, such as ferrous ion, Fe^^.

3 Lipe, LA. and M.D. C \rry ''ion Exch^ngn Water Softening," a discussion for water treatment plant operators, 1974-75 seminar seric
sponsored by Illinois Environmental Protection Agency.

ERIC

Softening 71

HARDNESS is i characteristic of water caused mainly by
the salts of ralcium and magnesium, such as bicarbonate,
carbonatf, sulfav^, chlonde and nitrate. Excessive hardness
in water is undesirable because it causes the formation of
soap curds, increased use of soap, deposition of scale in
boilers, damage in some industrial processes, and some-
t:mes may cause objectionable tastes in drinking water.

CALCIUM HARDNESS is :iused by calcium ions (Ca^^).

MAGNESIUM HARDNESS is caused by magnesium ions

TOTAL HARDNESS is the sum of the hardness caused by
both calcium and magnesium Ions.

CARBONATE HARDNESS is caused by the alkalinity
present in water up to the total hardness. This value is
usually less than the total hardness.

NONCARBONATE HARDNESS Is that portion of the total
hare '9SS in excess of the alkalinity.

yALMLMrv^lAL-ka-LIN-it-tee) is the capacity o* water to
neutralize ?jlds. This capacity is caused by the water's
content of carbonate, bicarbonate, hydroxide, and occasion-
ally borate, silicate, and phospiiate. Alkalinity is expressed in
milligrams per liter of equivalent calcium carbonate. Alkalin-
ity is a measure cf how much acid can be added to a water
without causing a great change in pH.

CALCiUM CARBONATE (CeCO^) EQUIVALENT is an
t <pression of the concentration of specified constituents in
Wcter in terms of their equivalent value to calcium carbonate.
For example, the hardness in water which is caused by
calcium, magnesium and other ions is usually described as
calcium carbonate equivalent.

14.1 WHY SOFTEN WATER?

The dissolved minerals (calcium and magnesium Ions) in
water cause difficulties in doing the laundry and in dishwash-
ing in the household. These ions also cause a coating to
form inside the hot water heater similar to that in a tea kettle
after repeated use.

Hardness, in addition to inhibiting the cleaning action of
soaps, will tend to shorten the life of fabrics that are washed
in hard water. The scum or curds may become lodged in the
fibers of the fabric and cause them to lose their softness and
elasticity.

In industry hardness can cajse Aven nreater problems.
Many processes are affected by the hardness content of the

wa.er used. Industrial plants usin*- boilers for processing
steam or heat must remove the t iess from their make-
up water, even beyond what a water treatment plant would
do. The reason for this is that the minerals will plate out on
the boiler tubes and form a scale. This scale forms an
insulation barriei which prevents proper heat transfer, thus
causing excessive energy requirements to fire the boilc s.
The problems associated with process water softening are
too numerous to go into; however, everything from food
processing to intricate manufactunng processes is affected
by the hardness of water

In addition to the removal of hardness frorn water, some
other benefits of softening include:

1. Removal of iron and manganese,

2. Control of corrosion when proper stabilization of water is
achieved,

3. Disinfection due to high pH values when using lime
(especially the excess lime softening process),

4. Sometimes a redi cti»^ii In tastes and odors,

5. Reduction of sorne total solids content by the lime treat-
ment process, and

6. Removal of radioactivity.

Possible limitations of softening might include:

1 . Free chlorine residual is predominantly liypochonte at pH
levels above 7.5 and is a less powerful disinfectant.

2. Costs and benefits must be carefully weighed to justify
softening.

3. Ultimate disposal of process wastes.

4. At the pH levels associated with softening chemical
precipitation, the tr: lomethane fraction in the treated
water may increase (depends on several othor factors).

5. Producing an "aggressive" water which would tend to
corrode metal ions from the distribution system piping.
Hard waters usually do not corrode pipe. However,
excessively hard water can cause scaling on the inside of
pipes and thereby restrict flow.

In many cases, the decision to soften the water is left up to
each community as softening is done mostiy as a customer
service. Hard water does not have an adverse effect on
health, but can create several unwanted side affects, some
of which are:

1 . Over a periou of time, the detergent-consuming power of
hard water can be very costly,

2. Scale problems on fixtures will be more noticeable, and

3. The life cycle of several types of clothing will be reduced
with repeated washing in hard water. Also, a residue can
be left in clothing, creating a dirty appearance.

Once the decision is made to soften, a method must be
selected. The two most common methods used to soften
water are chemical precipitation (lime-soda ash) and ION
EXCHANGE^. Ion exchange soft^-^ning can best be applied to
waters high in noncarbonate hardness and where the total
hardness does not exceed 360 mg/L. This method of
softening can produce a water of zero hardness, as op-
posed to lime softening where zero hardness cannot be
reached.

Ion Exchange. A water treatment ^ess involving the reversible interchange (switching) of ions between the water being treated and
the solid resin. Undesirable ions in the water are switched with acceptable ions in the resin.

72 Waiar Treatment

Ion exchange softening will also remove ncncarbonate
hardness without the addition of soda ash whicn is required
with lime softening. Ion exchange is a nonselective method
of softening. This means it will remove total hardness (the
sum of carbo. ite and noncarbonate hardness) making it a
very desirable means of water softening.

Limitations of the ion exchange softening process include
an increase in the sodium content of the softened water if
the ion exchanger is regenerated with sodium hydroxide
The sodium level should not exceed 20 mg/L in treated
water because of the potentially harmful effect on persons
susceptible to hypertension. Also the ultimate disposal of
spent brine and rinse waters from softeners can be a major
problem for many installations.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 1 07.

14.0A What causes hardness in wat*^

14 1 A Why IS excessive hardness unoesirable in a domestic
water supply'?

14.1B What are some of the limitations of the ion exchange
softening process?

14.2 CHEMISTRY CF SOFTENING

To understand how water hardness is described and also
how hardness is removed from water by softening proc-
esses, operators need to have an idea of the chemical
reactions that take place in water. In this section hardness,
pH, and alkalinity reactions in water will be discussed.

14.^u Hardness

Hardness is due to the presence of divalent metallic
cations in water, but the Fifteenth Edition of STANDARD
METHODS^ identifies only calcium and magnesium as hard-
ness constituents. Hardness is commonly measured by
TITRATION^ as described in Volume I on page 513. Individ-
ual divalent cations may be measured in the laboratory using
an atomic adsorption (AA) spectrophotometer for veiy accu-
rate work.

Hardness is usually reported as CALCIUM CARBONATE
(CaCOj) EQUIVALENTJ This procedure allows us to com-
bine or add up the hardness caused by both calcium and
magnesium and report the results as total hardness.

Calcium Hardness Equivalent Weight of CaC03

mg/LasCaC03 " ^^^^"^'^"^ "^"^^ ^^(^ii^>,^\eu\^Q,qhX o\ 0^\z'^^

= (Ca, mq/L) )
20

- 2 50(Ca, mg/L)

This equation indicates that if the ca'.dum concentration in
milligrams per liter is multiplied by 2.50. the result is the
calCium hardness in milligrams per liter as calcium carbon-
ate. The EQUIVALENT WEIGHT^ of most elements or
chemical radicals ^80/ is a radical) can be obtained by
dividing the molecular weight by the valence.

Equivalent Weight ^ Atomic Weight
of Calci' } Valence

- 20

To express the magnesium hardness of v»'ater as calcium
carbonate equivalent use the following formula.

Magnesium Hardness. Equivalent Weight oi CaC03

ng/LasCaCOa " ^Magnesium mniL) (gqu.vale.it Weight o. <)(.«b.o(ii J

= (Mg. mg/UCJJ^)

- 4 12 (Mg, mg/L)

The total hardness of water is the sum of the calcium and
magnesium hardness as CaCOg.

Total Hardness. ^ Calcium Hardness.^ Magnesium Hardness.
mg/L as CaCOg mg/L as CaCOg mg/L as CaCOg

EXAMPLE 1

Determine, thp total hardness as CaCOg for a sample of
water with a calcium content of 30 mg/L and a magnesium
content of 20 mg/L.

Known Unknown

Calcium. mg/L = 30 mg/L Total Hardness,

Magnesium. mg/L = 20 mg/L n^Q/^ as CaCOg

Calculate the total hardness as milligrams per liter of
calcium carbonate equivalent.

^ STANDARD MET^-IODS FOR THE EXAMINATION OF WATER AND WASTEWATER, 16th Edition, 1985. Order No. 1 0035. Available from
Data Processing Department, American Water Works Association, 6666 W. Quincy Avenue, Denver, Colorat^o 60235. Price to members
$72.00; nonrr embers $90.00.

6 Titrate (TIE-trate) To TITRATE a sample, a chemical solution of knov^/n strength is added on a drop-by-drop basis until a certain color
change, precipitate, orpH change in the sample is observed (end point). Titration is the process of adding the chemical reagent in incre-
ments until completion of the reaction, as signaled by the end point

7 Calvum Carbonate (CaCO^) Equivalent An expression of the concentration of specified constituents in water in terms of their
equivalent value to calcium carbonate For example, the hardness in water whicn is caused by calnum, magnesium and other ions is
usually described as calcium carbonate equivalent.

8 Equivalent Weight. That weight which will react with, displace or is equivalent to one gram atom of hydrogen. The equivalen weight of
an ^'lement (such as Ca^^) is equal to the atomic weight divided by the valence.

Molecular Weight

Equivalent Weight of CaCOs =

Number o^ Equivalents

" "2

ERIC

Softening 73

Total Hardness. ^ Calcium Hardness.^ Magnesium Hardness,
mg/L as CaCOg nrig/L as CaCOg mg/L as CaCOj

= 2 50(Ca. mg/L) + 4 12 (Mg. mg/l)

= 2 50(30 mg/L) + 4.12(20 mg/L)

=-- 75 mg/L + 82 4 mg/L

= 157.4 mg/L as CaCOa

Total hardness is also described as the sum of the
carbonate hardness (temporary hardness) and noncarbon-
ate hardness (permanent hardness).

Total Hardness. _ Carbonate Hardness. Noncarbonate Hardness.
mg/L as CaCO^ ^ mg/L as CaCOa mg/L as CaCOs

The amount of carbonate and noncarbonate hardness
depends on the alkalinity of the water. This relationship can
be descnbed as follows:

1. When the alkalinity (expressed as calcium carbonate
equivalent) is greater than the total hardness, all the
hardness is in the carbonate form.

Carbonate Hardness, ^ Total Hardness,
mg/L as CaCOg mg/L as CaCOg

2. When the total hardn^^a is greater than the alkalinity, the
alkalinity is carbonate hardness and noncarbonate hard-
ness Is the difference between total hardness and alkalin-
ity.

Carbonate Hardness. _ Alkalinity.
mg/L as CaCOs " mg/L as CaCOa

Noncarbonate Hardness.^ Total Hardness, _ Alkalinity.
mg/L as CaCOa ' mg/L as CaCOa mg/L as CaCO^

14.21 pH

pH is an expression of the intensity of the basic or acid
condition of a liquid. Mathematically, pH is the logarithni
(base 10) of the reciprocal of the hydrogen ion activity.

cH = Log

(H^)

The pH may range from 0 to 14. where zero is most acid. 14
most basic, and 7 neutral. Natural waters usually have a pH
between 6.5 and 8.5. Table 14.2 shows the relationship
between pH and hydrogen and hydroxide ions.

TABLE 1 4.2 RELATIONSHIP BETWEEN pH AND
HYDROGEN AND HYDROXIDF IONS

Hydrogen Ion (H**"),

Hydroxide Ion (OH ),

Moles/Liter

1.0

0.000 000 000 000 01

0.1

0.000 000 000 000 1

0.01

0.000 000 000 001

0.001

0.000 000 000 01

0.000 1

0.000 000 000 1

0.000 01

0.000 000 001

0.000 001

0.000 000 01

0.000 000 1

0.000 000 01

0.000 001

0.000 000 001

0.000 01

C 000 000 000 1

0.000 1

0.000 000 000 01

0.001

0.000 000 000 001

0.01

0.000 000 000 000 1

0.1

0.000 000 000 000 01

1.0

When treating waters th b pH is very important The pH of
water may be increased cr decreased by the acJition of
certain chemicals used to treat water (Table 14.3). In many
instances, the effect on pH of adding one chemical is
neutralized by the addition of another chemical When soft-
ening v;ater by chemical precipitation processes (lime-soda
softening for example), the pH must be raiced to 1 1 for the
desired chemical reactions to occur The leve's of carbon
diox'de. bicarbonaxs lor and carbonate ion in waters are
very sensitive to pH

I ABLE 1 4.3 INFLUENCE OF WATER TREATMENT
CHEMICALS ON pH

Lowers pH

Aluminum Sulfate (Alum),

Al2(SOJ3«18H20
Carbon Dioxide, COg
Chlorine, CIg
Ferric Chloride, FeClg
Hydrofluosilicic Acid, HgSiFg
SulfuncAcid. HgSO^

lacreases pH

Calcium Hypochlorite.

Ca(0CI)2
Caustic Soda, NaOH
Hydrated Llme,Ca(0H)2
Soda Ash, NagCOg
Sodium Aluminate, NaAlOg
Sodium Hydrochlorite,

NaOCI

ERIC

The stability of treated water is determined by measuring
the pH and calculating the Langelier Index (see Chapter 8,
"Corrosion Control," pages 357 to 360). This index reflects
the equilibnum pH of a water with respect to calcium and
alkalinity.

Langelier Index (L.L) = pH - pH^

pH = actual pH of water, and

pHg = pH at which water having the same
alkalinity and calcium content is
just saturated with calcium carbon-
ate

A negative LangeliL Index indicates that the water is corro-
sive and a positive index indicates that the water is scale
forming. After water has been softened, the treated water
distributed to consumers must be stable (neither corrosive
nor scale forming).

14.22 Alkalinity

Alkalinity is the capacity of water to neutralize acids. This
capacity is caused by the water's content of carbonate,
bicarbonate, hydroxide, and occasionally borate, silicate,
and phosphate. Alkalinity is expressed In milligrams per liter
of equivalent calcium carbonate. Alkalinity is measure of
how much acid can be added to a liquid without causing a
great change in pH.

74 Water Treatment

Alkalinity is measured in the laboratory by iUe addit. .r of
color indicator solutions and the alkalinity is then determined
by the amount of acid required to reach a titration end point
(specific color change) (see Chapter 1 1 , "Laboratory Proce-
dures," pages 491 to 493). The P (phenolphthalein) end point
is at pH 8.3. When the pH is below 8.3, there is no P alkalinity
present. When the pH is above 8.3, P alkalinity is present. No
carbon dioxide is present when the pH is above 8.3, so there
IS no carbon dioxide in the water when P alkalinity is present
Also, hydroxide and carbonate alkalinity are not present
when pH is below 8.3.

The relationship between the vanous alkalinity constitu-
ents (bicarbonate (HCO3-), carbonate (COg^-) and hydroxide
(OH")) can be based on the P (phenolphthalein and T (total or
methyl orange^ alkalinity as shown in Table 14.4 and Fiqure
14.1. ^

TABLE 14.4 ALKALINITY CONSTITUENTS
Alkalinity, mg/L as CaC03
Titration Result Bicarbonate Carbonate Hydroxide

P= 0

P is less than V2T

T-2P

P = V2T

P Is greater than V2T

2T-2P

2P-T

P= T

where P = phenolphthalein alkalinity
T = total alkalinity

When the pH is less than 8.3, all alkalinity is in the
carbonate form and is comrrjonly referred to as natural
alkalinity. When the pH is above 8.3, the alkalinity may
consist of bicarbonate, carbonate and hydroxide. As the pH
'ncreases, the alkalinity progressively shifts to carbonate
and hydroxide forms.

Total -ilkalinity is the sum of the bicarbonate, carbonate
and hydroxide. Each of these values can be determined by
measuring the P and T alkalinity in the laboratory and
referring to Taole 14.4. Alkalinity is expressed in milligrams
per liter as calcium carbonate equivalence. Alkalinity is
influenced by chemicals used to treat water as shown in
Table 14.5.

TABLE 14.5 INFLUENCE OF WATER TREATMENT
CHEMICALS ON ALKALINITY

•.owers Alkalinity

Aluminum Sulfate (AlumV

Al3(SOJ3.18H20
Carbon Dioxide, COg
Chlorine Gas, CI2
Ferric Chloride, FeCL
Ferric Sulfate, Fe2(S0

Sulfuric Acid, HgSO^

4/3

Increases Alkalinity

Calcium Hypochlorite,

Ca(0CI)2
Caustic Soda, NaOH
Hydrated Lime, Ca(0H)2
Soda Ash, Na2C03
Sodium Aluminate, NaAlO,

EXAMPLE 2

Results from alkalinity titrations on a raw water sample
were as follows:

Known

Sample size, mL =100 mL

mL titrant used to pH 8.3, A = 0 mL
Total mL of titrant used, B = 8.2 mL
Acid normality, N = 0.02 N H2SO4

Unknown

1. Total Alkalinity, mg/L as CaCOg

2. Bicarbonate Alkalinity, mg/L as CaCOg

3. Carbonate Alkalinity, mg/L as CaCOg

4. Hydroxide Alkalinity, mg/L as CaCOg

See Chapter 11, "Lab Procedures," pages 491-493 for
details and formulas.

Softening 75

1 Calculate the phenolphthalein alkalinity in mg//. as

CaC03.

Phenolphthalein ^ N ^ 50 000

Alkalinity.

mg/L as CaC03 sample

(0 mL) > (0 02 N) a (50.000)

100 mL

= 0 mg/L

2 Calculate the total alkalinity ir\ mg/L as CaCOg.

Total Alkalinity. _ B x N x 50.000
mg/L as CaCOj ni/_ of sample

(8.2 mL) X (0.02 N) x (50,000)

100 mL

= 82 mg/L

3. Refer to Table 14 3 for alkalinity constituents. The first
rov/ indicates that since P = 0. the total alkalinity is equal
to the bicarbonate alkalinity.

Bicarbonate Alkalinity, ^ Total Alkalinity.
mg/L as CaCOj mg/L as CaCOg

= 82 mg/L

The first row also indicates that since P = 0. the carbon-
ate and hydroxide alkalinlties are also zero.

Carbonate Alkalinity, n r««//
mg/LasCaC03 ' ^

Hydroxide Alkalinity. ^ q ,
mg/LasCaCOj ^^^jI-

QUESTiONS

Write your answers in a notebook and then compare your
answers with those on page 107.

14 2A What laboratory procedures are used to measure
hardness?

14 2B Determine the total hardness of CaC03 for a sample
of water with a calcium content of 25 mg/L and a
•nagnesium content of 14 mg/L.

14 20 Which water treatment chemicals lower the pH when
added to water?

1 4.2D Results from alkalinity titrations on a sample of water
were as follows: sample size. 100 mL; mL titrant
used to pH 8.3. 1.2 mL; total mL of titrant used. 5.6
mL. and the acid normality was 0.02 N KSO^.
Ca .ulate the total, bicarbonate, carbonate and hy-
droxide alkalinity as CaCOg.

14.3 HOW WATER IS SOFTENED

14.30 Basic Methods of Softening

The two basic methods of softening a municipal water
supply are chemical precipitation and ion exchange. Ion
exchange will be discussed in the second portion of this
chapter in Sections 14.10 through 14 21. We'll begin here
with the chemical precipitation methoos. mainly lirr.e-soda
ash softening and vanations of this process.

Hardness is not completely removed by the chemical
precipitation methods used in water treatment plants. That
IS. hardness is not reduced to zero. Water having a hardness
of 150 mg/L as CaCOj or more is usually treated to reduce
the hardness to 80 to 90 .ng/L v^hen softening is chosen as a
v;f,t::r treatment option

The minimum hardness that can be achieved by the lime-
soda ash process is around 30 to 40 mg/L as CaCOj. The
effluent from an ion exchange softener could contain almost
zero hardness. Regardless of the method used to soften
water, consumers usually receive a blended water with a
hardness of around 80 to 90 mg/L as CaCOj when softening
IS used in water treatment plants.

Lime-soda softening may produce benefits In addition to
the softening of water. These advantages include:

1 Removal of iron and manganese.

2. Reduction of solids,

3. Removal and inactivation of bacteria and virus due to high

4 Control of corrosion and scale formation with proper
stabilization of treated water, and

5 Removal of excess fluoride.

Limitations of the lime-soda softening process Include:
1 Unable to remove all hardness,

2. A high degree of operator control must be exercised for
maximum efficiency in cost, hardness removal and water
stability.

3. Color removal may be complicated by the softening
process due to high pH levels, and

4. Large quantities of sludge are created which must be
handled and disposed of in an acceptable manner.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 108.

14.3A What IS the minimum hardness that can be achieved
by the lime-soda ash process?

14.3B List some of the benefits that could result from the
hme-soda softening process in addition to softening
the water.

14.31 Chemical Reactions

In the chemical precipitation process, the hardness caus-
ing ions are converted from soluble to insoluble forms.
Calciurn and magnesium become less soluble as the pH
increases. Therefore, calcium and magnesium can be re-
moved from water as insoluble precipitates at high pH
levels.

Addition of lime to water increases the hydroxide concen-
trations, thus increasing the pH. Addition of lime to water
also converts alkalinity from the bicarbonate form to thj
c.'irbonate form which causes the calcium to be precipitated
as '.'alcium carbonate (CaC03). As additional lime is added to
the water, th^ ohenolphthaleir, (P) »'^lkalinity increases to a
level where hydroxide becomes present (excess causticity)
allowing magnesium to precipitate as magnesium hydroxide.

ERIC

76 Water Treatment

Following the chemical softening process, the pH is high
and the water is SUPERSATURATED^ with excess caustic
alkalinity in either the hydroxide or carbonate form. Carbon
dioxide can be used to decrease the causticity and scale
forming tendencies of the water prior to filtration.

The chemical reactions which take olace In water during
the ciiemlcal precipitation process a e described In the
remainder of this section. The procedures for softening
water derand on whether the ( ardness to be removed is
carbona. or noncarbonate hardness. Carbonate hardness
(also called "temporary hardness") can be removed by the
use of lime only. Removal of noncarbonat' ardness (also
called "permanent hardness") requires both lime and soda.

14.310 Lime

The lime used in the chemical precipitation softening
process may be from either HYDRATED LIME^^ (Ca(CH)2).
calcium hydroxide, or "slaked" lime) or calcium oxide (CaO,
QUICKUME^^ or "unslaked" lime). The hydrated lime may be
used directly. The calcium oxide or quicklime must first be
SLAKED.^^ This Involves adding the calcium oxide (CaO)
pellets to water and heating to cause "slaking" (the formation
of calcium hydroxide (Ca(0H)2)) hefore use. Small facilities
commonly use hydrated lime (Ca(0H)2). Large facilities may
*ind it .more economical to use quicklime (CaO) and slake it
on site.

14.31 1 Removal of Carbon Dioxide

The application of lime for the removal of carbonate
hardness also removes carbon dioxide. Carbon dioxide
does not contribute to hardness and therefore does not

eed to be removed. However, carbon dioxide will consume
a portion of the lime to be used and therefore must be
considered. Equation (1) describes the reaction of carbon
dioxide with lime.

(1) Carbon Dioxide ^ Ume -^Calcium Carbonatei + water

CO2 + Ca(OH)2- CaC03i 4 H2O

14.312 Removal of Carbonate Hardness

The equations bel' describe the removal of carbonale
hardness.

(2) Calcium Bicarbonate Ume — Calcium Carbonatel water

Ca(HC03H ^ Ca(0H)2 - 2 raC03| + 2 H2O

(3) Magnesium Calcium Magnesium
Bicarbonate^ ^ Carbonaiei ^ Carbonate ^ W^*®'

Mg(HC03)2 * Ca(0H)2 - CaC03i 4 MgC03 + 2 H2O

(4) Magnesium Calcium Magnesium
Carbonate ^ Carbonate| ^ Hydroxide|

MgC03 + Ca(0H)2-. CaC03l + Mg(0H)2l

When lime is added to water, any carbon dioxide present is
converted to calcium carbonate if enough iime is added
(Equation 1). With the addition of more lime the calcium
bicarbonate will be precipitated as calcium carbonate. To
remove both the calcium and magnesium bicarbonate, an
excess of lime must be used.

14.313 Removal of Noncarbonate Hardness

Magnesium noncarbonate hardness requires the addition
of both lime and soda ash (sodium carbonate, Na2C03).

(5] agnesium Sulfate Ume _ Magr.asium Hydroxide] ( Actum Sulfate
MgS04 + Ca(0H)2- Mg(0H)2 + CaS04

(6) Caic um Sulfate 4 Soda Ash ^ Calcium Carbonate] Sodium Sulfate
CaS04 + Na2C03 - CaC03i + Na2S04

Equation (6) is also one of the equations ,or the removal of
calcium noncarbonate hardness. Similar equaJons can be
written for the removal of noncarbonate hardness caused by
calcium and magnesium chloride.

14.314 Stability

The main chemical reaction products from the lime-soda
softening process are CaC03l and Mg(0H)2l. The water thus
treated has been chemically changed and is no longer stable
because of pH and alkalinity changes. Lime soda softened
water Is usually supersaturated with calcium carbonate
{CaC03). The degree of instability and excess calcium car-
bonate depends on the degree to which the water is sof-
tened. Calcium carbonate hardness is removed at a lower
pH than magnesium carbonate hardness. If maximum car-
bonate hardnesc removal is practiced (thus requiring a high
pH to remove the magnesium carbonate hardness), the
water will be supersaturated with calcium carbonate and
magnesium hydroxide. Under these conditions deposition of
precipitates will occur in filters and pipelines.

Excess lime addition to remove magnesium carbonate
hardness results In supersaturated conditions and a residual
of lime which will produce a pH of about 10.9. The excess
lime is called caustic alkalinity since it has the effect of
raising the pH. If the pH Is then lowered, better precipitation
of calcium carbonate and magnesium hydroxide will occur.
Alkalinity will be lowerc^ also. This is usually accomplished
by pumping carbon dioxide (CO2) gas into the water. This
addition of carbon dioxide to the treated watei is called
RECARBONATfON.^^

Recarbonation may be carried out in two steps. The first
addition of carbon dio) ide would follow excess lime addition
to lower the pH to about 1 0.4 and encourage the precipita-
tion of calcium carbonate and magnesium hydroxlae. A
second addition of carbon dioxide would be after treatment
to remove noncarbonate hardness. This would again lower
the pH to about 9.8 and would encourage precipitation. By

^ Supersaturated. An uristable condition of a solution (water) in which the solution contains a substance at a concentrat on greater than
the saturation concentration for the substance.

Hydrated Lime. Limestone that has been "burned" and treated with water under controlled conditions until the calcium oxid3 portion
has been converted to calcium hydroxide (Ca(0H)2). Hydrated lime is quicldime combined with water. CaO + HoO — CaiOHU. Also
called slaked limo.

^ ^ Quicklima. A material that m?sf/y calcium oxide (CaO) or calciun: oxide in natural assomation with a lesser amount of magnesium
oxide. Quicklime is capable of combining with water to form hydrated lime.

^2 Slake. To mix with water with a true chemical combination (hydrolysis) taking place, such as in the shaking of lime.

13 Recarbonation (re-CAR-bun-NAY-shun). A process in which carbon dioxide is bubbled into the water being treated to lower the pH.
The pH may also be lowered by the addition of acid. Recarbonation is the final stage in the lime-soda ash softening process. This proc-
ess converts carbonate ions to bicarbonate ions and stabi'izos the solution against the precipitation of carbonate compounds.

ERIC 88

Softening 77

carrying out recarbonation prior to filtration, the build up of
excess lime and also calcium carbonate and magnesium
hydroxide precipitates in the filters will be prevented or
minimized. The recarbonation reaction *or excess lime re-
moval is shown below.

(7) Calcium Hydroxtde Carbon Dioxide « Calcium Carbonatei Water

Ca(0H)2 ^ CO2 ^ CaC03l H2O

Care musi be exercised when using recarbonation Feed-
ing excess carbon dioxide may result in no lowering of the
hardness by causing calcium carbonate precipitates to go
back into solution and cause carbonate hardness.

(8) Calcium Carbonate r Carbon OiOxide -f Water ^ Calcium Bicarbonate

CaC03 . CO2 + H2O — Ca(HC03)2

14.315 Caustic Soda Softening

An alternate method in the lime-soda softening process is
the use of sodium hydroxide (NaOH, often called caustic
soda) place of soda ash. The chemical reactions of
scdiurr. .ydroxide with carbonate and non-carbonate hard-
ness are listed beiow.

(9) Carbon DiOxide ^ Sodium Hydroxide-^ Sodium Carbonate Water
CO2 + 2NaOH — Na2C03 + H2O

(10) Calr4um
Btcartx)nate

Sodium
Hydroxide""

Ca(HC03)2 + 2 NaCH —

Calcium
Carbonatei

Sodium ... .
Carbonate* water

CaC03i + Na2C03 + 2 H2O

(11)

Magnesium
Bicart>onate

Sodium
Hydroxide

Mg(HC03)2 + 4 NaCH - M9(OH)2l

Magnesium
Hydroxide!

Sodium

. + Water

Carbonate
+ 2 Na2C03 + 2 H2O

ERLC

(12) Magnesium Sodium Magnesium Sodium
Sulfate Hydroxide"" Hydroxide! Sulfate

MgS04 ^ 2 NaOH ^ Mg{0H)2 ^ Na2S04

These chemical reactions show that in removing carbon
dioxide and carbonate hardness, sodium carbonate
(Na2C03, soda ash) is formed which will react to remove the
noncarbonate hardness. Not only will sodium hydroxide
substitute for soda ash, but it may replace all or part of the
lime (Ca(0H)2) requirement for removal of the carbonate
hardness. The use of caustic soda (usually as a 5C percent
solution) may have several ?dvantages:

1 . Stability in storage,

2. Less sludge is formed, and

3. Ease of handling and storage.

Safe handling procedures for caustic soda must be used
at ail t'mes. A 50 percent caustic solution is very dangerous.
Caustic soda Is a strong base and will attack fabrics and
leather and cause severe burns to the skin. Rubber gloves,
respirator, safety goggles and a rubber apron must be worn
when handling caustic soda. A safety shower and an emer-
gency eye wash must be readily available at all times.

The decision to use caustic soda rather than soda ash
depends on the quality of the source water ano me deliver^jd
costs of the various chemicals.

QUESTIONS

Write your answers in a notebook and then compare your
answers wi^h those on page 108.

14.3C What causes the pH to increase during the lime-soda
softening proces*;?

14 3D Why is the pH increased during the lime-soda soften-
ing process'?

USE How are the scale forming tendencies reduced in
water after the chemical softening process'^

14 3F Under what condiuons might caustic soda softening
be used'?

14.316 Calculation of Chemical Dosages

There are several dif.'arent approaches to calculating
chemical doses for the lime-soda softening process. This
section Illustrates one step-by-step procedure. To use this
procedure you need to obtain a chemical analysis of the
water you are softening. From this analysis obtain the
known values for your water similar to the "Knowns" listed m
EXAMPLE 2. Then calculate the dosages of chemicals for
your water by following the steps in the example.

To help you understand where some of the numbers como
from m the formulas, we have listed the molecular weights of
the major chemical components involved in the chemical
precipitation softening process.

Quicklime, CaO

= 56

Hydrated Lime, Ca(0H)2

= 74

Magnesium, f^g^*

= 24.3

Carbon Dioxide, CO2

= 44

Magnesium Hydroxide, Mg(0H)2

= 58.3

Soda Ash, Na2C03

= 106

Alkalinity, as CaCOj

= 100

Hardness, as CaC03

= 100

FORMULAS

1 The lime dosage for softening can be estimated by using
the following formula:

Quicklime (CaO) ^ (A + B + C + 0)1.15

Feed, mg/L

Where A =

B =

Purity of Lime, as a decimal

: CO2 in source water
(mg/L as C02)(56/44)

Bicarbonate alkalinity removed in softening
{mg/L as CaCOaXSe/lOO)

C = Hydroxide alkalinity in softener eff luer :
(my/L as CaC03(56/1 00)

D = Magnesium removed in softening
, ^g|L as Mg2+K56/24.3)

1.15 = Excess lime dosage

(using a 15 percent excess)

NOTE If hydrated lime (Ca(0H)2) is used instead of quick-
lime substitute 74 for 56 in A, B, C and D.

2 The soda ash dosage to remove noncarbonate hardness
can t3 estimated by using the formula below.

^^^eeTmglL^^^^^' (Noncarbonate Ha-iness. tngfL asCaCO3K106/100)

3 The dosage of carbon dioxide required for recarbonation
can be estimated using the formula below.

Total COo

Feed, mg/L

^ (CavOH)2 excess, mg/L)(44/74)

f (Mg(0H)2 residual, mg/L)(44/58.3)

78 Water Treatment

EXAMPLES

Calculate the hydra*ed lime (CatOH)^) with 90 percent
purity, soda ash, and carbon dioxide dose requirements in
milligrams per liter for the v/ater shown below.

Known

Softened Water
After Recarfoonation
Source Water and Filtration

6 mg/L = 0 mg/L

170 mg/L as CaC03= 30 mg/L as CaCOa
280 mg/L as CaCOa^ 70 mg/L as CaCOa
= 3 mg/L
= 8.8

Constituents

CP2. mg/L
Total Alkalmtty, mg/L
Total Hardness, mg/L
Mg2*, mg/L = 21 mg/L

pH = 7.5

Lime Purity, % = 90%

Unknown

1. Hydrated Lime, mg/L

2. Soda Ash, mg/L

3. Carbon Dioxide, mg/L

1. Calculate the hydrated lime (CapHjj) required in milli-
grams per liter.

A =

B =

C =
D

(CO2, mg/L)(74/44)
(6 mg/LM74/44)
10 mg/L

(Alke:inity, mg/LX74/100)
= (170mg/LX74'' )0)
■■ 126 mg/L

= 0

= (Mg2*, mg/L)(74/24.3)
= (21 mg/L)(74/24.3)
= 64 mg/L

Hydrated Lime
(Ca{0H)2) Feed, ^
mg/L

(A + B + C + D)1.15

Purity of Lime, as a decimal
10 mg/L -f 126 mg/L + 0 + 64 mg/L)1.15
"090

^(200 mg/LM1.15)

O90
= 256 mg/L

2. Calculate t.ie soda ash required in milligrams per liter.

Noncarl)onate Hardness, ^ Total Hardness, _Cart>onate Hardn'*':,
mg/L as CaCOa " mg/i. as CaCOa ~ mg/L as CaCOa

= 280 mg/L - 170 mg/L

« 110 mg/L as CaCOa

Soda Ash (NapCQa) _ / Noncarbonate Hardness, . ,^naitM\
Feed. mg/L * " ^ mg/L as CaCOa ^ ^06/100)

= (I10mg/L)(106/100)
= 117 mg/L

3. Calculate the dosage of ca*'bon dioxide required for
recarbonation.

Excess Ume, mg/L - (A + B + C + OX0.15)

« (10 mg/L + 126 mg/L +0 + 6^ mg/LK0 15)

- (200mg/LX0.15)

- 30 mg/L

Total CO2 ^(Ca(0H)2 excess, mg/L)(44/74)
Feed, mg/L ^ (f^g2- residual, rng/L)(44/24.3)

= (30 mg/L)(44/74) + (3 mg/L)(44/24.3)
= 18 mg/L + 6 mg/L
= 24 mg/L

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 108.

1 4.3G Calculate the hydrated lime (CiJOHlj) with 90 percent
purity, soda ash, and carbon oioxide dose require-
ments in milligrams per liter for the water shown
below.

Softened Water
After Recarbonation
Constituents Source Water and Filtration

CO2, mg/L = 5 mg/L = 0 mg/L

Total Alkalinity, mg/L = 150 mg/L as CaCO =^ 20 mg/L as CaCO

Total Hardness, mg/L= 240 mg/L as CaCO = 50 mg/L as CaCO

Mg2\ mg/L = 16 mg/L = 2 mg/L

pH = 7.4 = 8.8

Ume Pu'ity, % = 90%

14.32 Lime Softening (Figure 14.2)

Water having hardness caused by calcium and magne-
sium bicarbonate (carbonate hardness) can usually be sof-
tened to an acceptable level using only lime. The lime reacts
with the bicarbonate to form calcium carbonate which will
precipitate and settle out (convert from soluble to insoluble
form) at a pH above 1 0 and magnesium carbonate which will
remain in solution. The magnesium carbonate reacts with
additional lime at a pH above 11 to form magnesium
hydroxide which will precipitate.

In practice, if enough hardness can be removed by react-
ing lime with the calcium bicarbonate, softening can be
accomplished at less expense. This procedure is sometimes
called partial lime softening (no magner^iu. removal). On the
other hand, if some of the magnesium is to be removed,
additional lime will be required.

Figure 14.2 is a flow diagram of a typical straight lime
softening treatment plant. Settling should be provided after
the addition of carbon dioxide (recarbonation) to ease the
load on the filters. Recarbonation is used to lower the pH of
the water. When properly recarbonated the water is still
supersaturated with calcium cartK)nate {CaC03), If the pH is
much above 9, the water will usually cause scale to form. By
recarbonation the pH can be lowered to a range between 8.8
and 8.4 and the Langelier Index will still be positive; there-
fore there will be little or no corrosion. A polyphosphate is
sometimes added to the water to prevent excessively heavy
calcium carbonate scale deposits from forming. A polyphos-
phate may not be necessary if recarbonation is prope ^ly
controlled. Addition of acid will A/07 accomplish the sarne
things as recarbonation and the addition of a polyphos-
phate.

14.33 Split Treatment

The amount of calcium and magnesium in source waters
may vary. When the water contains a high level of magne-
sium, a method known as split treatment may be uoed
(Figure 14.3). Split treatment can be used in lime treatment

ERLC

Softening 79

only or lime-soda ash treatment. In split treatment a portion
of the water (say 90 percent) is treated with an excess
amount of lime to remove the magnesium at a pH of over 1 1 .
Then source water (the other 20 percent) is added in the next
basin to neutralize (lower the pH) the excess-llme-tteated
portion. The percentages will vary depending upon the water
hardness, treatment layout, and desired results.

Split treatment softening can eliminate the need for recar-
bonation as well as offer a significant savings in lime feed.
Since the fraction of the water that is treated has a high lime
dose, magnesium is almost completely removed from this
portion. When this water is mixed with the unsoftened water,
the carbon dioxide and bicarbonate in the unsoftened trac-
tion of the water tend to recarbonate in the final blend or mix
of the treated water (effluent).

If the water shown In Figure 14.4 was treated by conven-
tional treatment (not split treatment), it would require a lime
dose of 400 mg/L as CaCOg which is 25 percent higher and a

carbon dioxide dose of 145 mg/L as CaCOg to produce a
water having a hardness of 61 mg/L as CaCOa and a pH of
8.63.

While split treatment may be used in the lime-soda proc-
ess. It IS often aovantageous to use a lime-ion exchange
process (see Section 14.10). The salt used to remove
noncarbonate hardness in the ion exchange process is
much less expensive than the soda ash required in the lime-
soda ash process.

The curves shown in Figure 14.4 assume that carbonate
equilibrium has been achieved. In practice, it is not possible
to a'ltain equilibrium, but if the reactions take place in solids-
contact units the results are very close to carbonate equilib-
rium.

The proper fraction of water to bypass is rather critically
dependent on the lime dose and chemical composition of the
unsoftened ;vater. The proper fraction may be calculated,
but the calculations are very complex. An experienced water
chemist can perform the calculations.

COAGULANT
LIME

SOURCE

ILIM

MIX

SETTLE

CO2

FILTERS

SETTLE

(OPTIONAL)

Fig. 14.2 Straight lime treatment

LiME

SOURCE

MIX

SETTLE

MIX

BYPASS
COAGULANT

CO2

SETTLE jJ\ *^I-EAR \

I piz^W W.U )

P04 P04

P04

(OPTIONAL)

Fig. 14.3 Split lime treatment

ERIC

80 Water Treatment

UNSOFTENED WATER

TEMPERATURE = 25°C Ca = 150 mg/L as CaCOa

TDS = 400mg/L Mg = 100 mg/Las CaCOa

PH = 7.2 Alk = 250 mg/L as CaCOs

DOSAGE

LIME = 320 mg/L as CaCOs

UNSOFTENED WATER BYPASSED, %

ERIC

F/g. 14.4 Spin treatment softening

Softening 81

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 109.

14 3H What compounds are formed when calcium and
magnesium are piecipitated out of water in the lime
softening process?

14.31 What hardness is removed by partial lime softening
(no magnesium removal)?

14 3J What is split lime treatment?

14.3K What IS recarbonation'?

14.34 Lime-Soda Ash Softening

Let's look now at hardness requiring lime-soda ash treat-
ment for removal (Figure 14.5).

When water cannot be softened to the desired level with
lime only, it no r'.dbt contains noncarbonate hardness.
Noncarbonate hardness requires the addition of a com-
pound which increases carbonate concentration, usually
soda ash (sodium carbonate).

A water could contain only calcium hardness, yet require
both lime and soda ash treatment. This would occur if the
hardness were only calcium bicarbonate, sulfate and/or
chloride. In other words, all of the hardness is calcium
carbonate and calcium noncarbonate hardness. This would
not require split treatmen* (Figure 14.6).

14.35 Caustic Soda Softening

An alternative to the lime-soda ash process is the use of
caustic soda (sodium hydroxide, NaOH) instead of soda ash.

The reactions of caustic soda with the carbonate and
noncarbonate hardness are given in Section 14.315. Recall
that caustic soda reacts with the carbonate hardness to form
soda ash (sodium carbonate) which will react with calcium
sulfate to form calcium carbonate (CaCOgl) as Phown pre-
viously.

The advantages of using liquid caustic soda include ease
of handling and feeding, lack of deterioration in storage, and
less calcium carbonate sludge to handle and dispose of.
Caustic soda is capable of removing both carbonate and
noncarbonate hardness. Therefore, caustic soda may be
used instead or soda ash, but also in place of part or all of
the lime requirement. The use of caustic soda depends on a
comparison of the costs of caustic joda, lime and soda ash
and the characteristics of the source water.

LIME

SOURCE

SODA ASH

MIX

COAGULANT

PO4

(OPTIONAL)

Fig. 14.5 Lime-soda ash treatment

SOURCE

J ''^4

I (OPTIONAL)
COAGULANT

Fig. 14.6 Lime- soda ash split treatment

82 Water Treatment

Two points to observe are that sodium does not contribute
to hardness, thus all the reactions having sodium com-
pounds as an end product are non-hardness-producing
compounds However, sodium levels in dnnking water
should be less than 20 mg/L The second point is that the
precipitated compounds, CaCOjl and Mg(0H)2l are the
desired end products whether lime or lime-soda ash or
caustic soda treatment is used.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 109.

14.3L Under what conditions would lime-soda ash soften-
ing be used'?

14.3M What chemical is used to remove noncarbonate
hardness in the chemical precipitation softening pro-
cess?

14.36 Handling, Application and Storage of Lime

Where the daily requirements for lime are small, lime is
usually delivered to the water treatment plant in bags. At
larger treatment plants either quick (CaO) or hydrated
(Ca(0H)2) lime is delivered in bulk quantities. Truck loads of
lime are commonly transferred to weather-tight bins or silos
by mechanical or pneumatic conveying systems.

Storage areas for bagged lime must be covered to prevent
ram from wetting the bags. Bagged quicklime (CaO or
calcium oxide) should never be stored close to combustible
materials because considerable heat will be generated if the
lime accidentally gets wet. Quicklime may be stored as long
as six months, but in general should not be stored over three
months. Hydrated lime should not be stored for more than
three months before using.

Lime may be applied by dry feeding techniques using
volumetric or gravimetric feeders. Lime is too insoluble to
make "solution feeding" by pump feeders practical because
of the accumulation of carbonate precipitation. See Chapter
13, "Fluoridation," for additional details and pictures of the
various types of chemical feeders.

Operator safety must be considered before atternpting to
work with lime. A properly designed lime feeding system can
minimize or eliminate lime dust problems. If lime dust is a
problem, operators must wear protective clothing to avoid
burns from contact with lime. Protective clothing includes
long-sleeved shirt with sleeves and collar buttoned, trousers
with legs down over tops of shoes or boots, head protection,
and gloves. Clothing should not fit too tightly around your
neck, wrists or ankles, A protective cream should be applied
to exposed parts of the body, especially your neck, face and
wrists. You should wear a light-weight filter mask and tight-
fitting safety glasses with side shield to protect yourself from
the lime dust.

If lime comes in contact with your skin or eyes, immediate-
ly flush the affected areas with water and consult a physician
if necessary. Do not rub your eyes if they are irritated with
lime dust because rubbing make the irritation worse.
Keep any hme burns cohered with a banddge during healing
to prevent infection.

After handling lirne, you should take a shower. If your
clothes are covered with dust, or splattered with a lime
slurry, take them off and have them washed. If possible,
wear clean clothes on every shift.

For additional information regarding lime, contact the
National Lime Association, Washington, D.C. 20016, and
request a copy of their publication, LIME HANDLING, AP-
PLICATION. A,'^n r^TORAGE IN TREATMENT PROC-
ESSES. Lime, as well as other water treatment chemicals,
should comply with the Standards of the American Water
Works Association.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 109.

14 3N How IS lime delivered to plants where the daily
requirements are small?

14.30 Why should quicklime be kept dry'?

1 4 3P What types of chemical feeders are used to apply dry
lime?

14.4 INTERACTIONS WITH COAGULANTS

Coagulation is discussed in detail in Chapter 4, "Coagula-
tion and Flocculation." However, the interactions of lime and
soda ash with metallic coagulants such as alum, iron salts
(fernc chloride, ferric sulfate and ferrous sulfate), sodium
aluminate, and many polymers are important.

Alum and iron salto are acidic and react with the alkalinity
in water to cause a demand the same way that fiee carbon
o.oxide will. Therefore, this acidic condition must be met
before softening can occur. In other words, extra lime will be
required as the alum or iron feed rate goes up and therefore,
less hme will be required as the alum or iron feed rate is
reduced. Cationic polymers are not very pH sensitive and
are often used as coagulant aids in softening plants rather
than alum or iron salts.

On the other hand, when sodium aluminate (a basic rather
than an acidic compound) is the coagulant, the lime required
to achieve a specific hardness reduction will be less, and will
vary the opposite of alum or iron salts.

The proportion of lime required in either instance is
directly related to the coagulant dosage as well as the
hardness removal desired. Approximate relationships can
be calculated; however, experimentation is in order since
plant equipment and source water variations are primary
factors in the efficiencies of each waterworks. Jar tests are
discussed later in Section 14.9.

If you are treating, highly colored waters, these waters
must be coagulated for color removal at low pH values. Alum
IS a good coagulai.t under these conditions. Ozone, perman-
ganate and chlorine may be tried along with alum to oxidize
color. The high pH values required during softening tend to
"set" the color which then becomes very difficult to remove.

Softening 83

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 109.

14.4A What happens to the lime dose when the alum do*^,3
IS increased for coagulation'^

14.4B How can color be removed from water'^

14.5 STABILITY

In nature, most waters are more or less stable. That is,
they are in chemical balance. When lime is added, the
chemical balance is changed. The calcium carbonate
(CaCOg) formed m lime treatment is scale forming unless the
exact chemical balance is achieved, which is seldom the
case.

Under most conditions, a slight excess of lime is fed to
cause a caustic condition to insure complete reactions and
achieve the desired results In order to prevent scale forma-
tion on the filter sand, dii*ribution mains, and .household
plurnuing, the excess caustiC and unprecipitated carbonate
ions (pin floe) must be converted to soluble forms. Recar-
bonation is the mobi common way to do this Again, as with
all chemical treatment, recarbonation must be controlled to
achieve the desired results.

Recarbonation lowers the pH to about 8.8 and thus
converts some of the carbonate (00^~) back to the original
bicarbonate (HCO3") that existed in the source water. Recar-
bonation can be accomplished, to a degree, by using thp
source water in the split treatment mode discussed earlier.
Usually this is not adequate so further recarbonation is
required. One reason for using source water as a neutraliz-
ing agent is that the recarbonation process is much less
costly than if a high caustic water (high pH) is neutralized by
chemical addition.

Usft of carbon dioxide gas is the most common method of
recarbonation. The reactions are:

1. Ca(0H)2 + CO2 + HgO Ca(HC03)2 and

2. CaCOg + CO2 + Hp Ca(HC03)2.

These reactions may be looked at as lime softening in
r 'verse and will increase the hardness slightly. In these
r<jactions you are producing bicarbonate ions which were
removed in softening as carbonate hardness. This process
tends to move the water back toward its original state, thus
rendenng it more stable.

The use of acids such as sulfuric or hydrochloric instead
of recarbonation with carbon dioxide (CO2) does nci pro-
duce the same results. When carbon dioxide is added to a
water containing calcium ions (Ca^*) and hydroxide ions
(OH"), a calcium carbonate (CaCOg) precipitate will f-^rm and
the water will be saturated (or supersaturated) with calcium
carbonate. If a strong acid is added to neutralize the
softened water which is highly basic, these reactions will not
take place.

The marble test is the simplest method of measuring
stability in the laboratory. Run the marble test^^ as outlined
below:

1 . Collect a sample of tap water that has been softened and
stopper the sample bottle (avoid splashing into the flask).

2. To an identical sample, add one gram of powdered
calcjum carbonate. Mix and let stand for an hour or so.

3 Filter both samples (so they are both exposed to the
same conditions).

4. Run pH and alkalinity tests on both samples.

5. The goal is to have the sample of softened tap water as
nearly matched lo the softened sample treated with
calcium carbonace as possible. Then stability is near. The
plant treatment must be controlled to permit this condi-
tion to exist. If the pH and alkalinity in the softened
sample are higher than in the softened sample treated
with calcium carbonate, ycu are probably over-treating
your supply and have scale-forminq water. But, if the pH
and alkalinity in your untreated softened sample are
lower than in the treated one (calcium carbonate added),
you are undertreating your supply. If they are similar, then
stability is near.

Another way to check your water is to suspend a couple of
nails on strings in your filter. ODssrve the nails occasionally
to if they are rusting or scaling up. Tc further protect the
distnbution system as well as prevent scale formation in the
filter bed, 0.7 \o 1.0 mg/L polyphosphate could be fed ahead
of the filters at such a d'stance to allow mixing before it goes
on to the filters. Addition of polyphosphate can PREVENT
THE FORMATION OFSCALEon filter media and in distribu-
tion system mains, but polyphosphate does NOT prevent
corrosion. The Langelier Index (see pages 357 to 360 in
Volume I) IS another approach to determining the corrosivity
of water.

Caution should be exercised when using polyphosphate
compounds. If they are converted to the orthophosphate
form, they will lose their effectiveness. With the addition of
phosphorous to water, there could be an increase in bacte-
iial growths in the distribution system. Also some
wastewater treatment plants have phosphorous discharge
limitations and polyphosphates added to drinking water can
cause wastewater treatment plants to violate their discharge
requirements.

For additional information on the marble test, see Chapter 21, ''Advanced Laboratory Procedures," Test Procedure 9, Marble Test.

ERIC ;r 9^

84 Water Treatment

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 109.

1 4.5A What problems are sometimes created when a slight
excess of lime is fed during softening to cause a
caustic condition to insure complete reactions'?

14.5B How can excess caustic and unprecipitated carbon-
ate ions (pin floe) be removed from softened water?

14.5C What test is used to determine if a water is stable?

14.5D How can nails be used to determine if a water is
stable?

14.6 SAFETY

When quicklime reacts with water in the slaking process
(Figure 147), it gets hot enough to cause serious burns.
Also, being caustic in nature, it can harm your eyes and skin.
ALWAYS vjear goggles or a face shield when working with
lime that has been or is in the process of slaking. Flush with
water if exposed to lime. Seek medical attention if it gets in
your eyes. As for hands or face burns, immediately wash the
affected areas and consult a physician if the burns appear
serious.

Feeding equipment has moving parts. All moving machin-
ery IS a potential safety hazard. A paste-type slaker is
particularly dangerous. This type of slaker will "eat you
alive " Never put your hand In or near the slaker paddles
while the slaker is running. Use wooden paddles as cleaning

tocis on any slaker in operation. A metal tool will damage the
slaker and could even injure the operator if dropped by
accident However, a wooden paddle is less likely to damage
the equipment or the operator.

Types of equipment vary greatly. Usually the operator has
little or no input in this area. Engineers usually design a plant
and specify the type of chemical feed equipment.

Equipment suppliers are usually quite cooperative in ad-
vising any ope'-ator in the use and care of their equipment in
your treatment plant.

Detailed startup and shutdown and maintenance proce-
dures are available in the equipment manuals.

Another important safety precaution is to avoid using the
same conveyor or uin for alternately handling both quicklime
and one of the coagulants containing water, such as alum,
ferric sulfate or copperas. This water may be withdrawn by
the quicklime and could generate enough heat to cause a
fire Explosions have been reported to have been caused by
lime-alum mixtures in enclosed bins. Therefore, always
clean facilities before switching from one chemical to an-
other

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 109.

14 6A Why should wooden paddles be used as cleaning
tools on any slaker in operation?

14.6B Where would you look for information on how to
safely maintain equipment?

ERLC

Fig, 14 J Ume-siakmg system

(Permission of Wallace & T:ernan Division. Pennwait Corporation)

Softening 85

147 SLUDGE RECIRCULATION AND DISPOSAL

Considerable sludge may be produced by the lime and
lime-soda softening processes. When calcium and magne-
sium hardness are converted from soluble lorms to insolu-
ble precipitates (calcium carbonate and magnesium hydrox-
ide), these precipitates form sludge. This sludge is removed
from the bottom of settling basins and may be recirculated
or must be disposed of by an acceptable procedure.

in some instances, sludge is recirculated back into the
primary mix area of conventional plants to help "seed" the
process. The advantages are (1) recirculation speeds up the
precipitation process and (2) some reduction of chemical
requirements may result. One disadvantage is that an in-
crease m magnesium could result. Only trial and error wili
really dete''mine »^ sludge •'ecrculation will serve a useful
purpose in your plant.

Sludge disposal is a problem everywhere. Perhaps the
most common method is landfill disposal. This is accom-
plished by dewatering the sludge (drying beds or mechanical
means) and then hauling the sludge to landrill sites devel-
oped solely for sludge disposal or sanitary landfills. General-
ly, a sludge with a Ca Mg ratio of less than 2.1 will be difficult
to dewater, whereas r. sludge with a Ca Mg ratio of greater
than 5:1 will dewater relatively easily. The less water in the
sludge, the less volume to transport to the disposal site and
the less space required in the landfill.

To a lesser degree, sanitary sewer disposal is sometimes
used. This only moves ihe sludge to another location for
someone else to deal with. Some work has also been done
with land application as a substitute for agriculture lime to
increase the pH of highly acid soils. The lime sludge is
applied at a rata which will produce the 'optimum soil pH for
the crops to be planted. For additional information on sludge
disposal, see Chapter 17, Handling and Disposal of Proc-
ess Wastes."

14.8 RECORDS

Records should be kept on the amounts of chemicals
ordered and the amounts fed Laboratory results should be
recorded in a permanent lab book. See Chapter 18, "Mainte-
nance," for details on how to keep equipment maintenance
schedules and records.

Again, every plant is different. However, records will help
a good operator be a better operator

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 109.

14.7A What \$ a disadvantage of recirculating sludge back
to the primary mix area'^

14.7B How could you determine if sludge recirculation will
serve a useful purpose in your planf?

14.8A What types of records should be kept regarding
treatment plant chemicals?

14.9 JAR TESTS

14.90 Typical Procedures

Approximate amounts of chemicals required can be calcu-
lated (see Section 14.316, "Calculation of Chemical Dos-
ages"), however, the best method of determining the proper
dosages is by the use of the jar test. See Chapter 11,
"Laboratory Procedures," for details on the equipment and
procedures required to run jar tests.

Cnem;cal reagents may be made up by adding one gram
of reagent to a liter of water.^^ This will produce a 0.1
percent chemical solution. When 1.0 gram/liter of lime, soda
ash or coagulant Is made up as the stock solution, one mL of
the stock solution in a one liter sample of water equals one
mg/L dosage. If large doses of lime are required, add 10
grams of lime per liter. With this stock solution, one m/. of
stock solution in a one liter sample of water equals ten mg/L
dosage

Set up 6 samples and estimate the dosage required by
adding varying amounts to each sample. Trial and error will
put you in the "ball park." To refine the dosage, pick the best
looking sample from the settling properties of the floe to
establish the optimum lime dose. Then do the same with
varying amounts of soda ash, leavin^ the Isme dosage
constant. By running pH, alkalinity, and hardness tests you
can find the optimum dosages that give the desired softened
water results.

The exact procedures used to soften water by chemical
precipitation using the lime-soda ash process depend on the
hardness and other chemical characteristics of the water
being treated. A series of jar tests are commonly used to
determine optimum dosages. In many cases, the feed rates
dete''mmed by jar tests do not produce the exact same
results in an actual plant. This is because of differences in
v^'ater temperature, size and shape of jar as compared with
plant basins, mixing equipment, and influence of coagulant
(a heavy alum feed will neutralize more of the lime). You
must remember that jar test results are a starting point. You
may have to make additional adjustments to the chemical
feeders in your plant based on actual analyses of the treated
water.

Convert the jar tei,t results to plant feed rates Always feed
enough chemical to achieve the desired results, but don't
overfeed. Over . .ing is a waste of money and quality
control will suffer.

^5 Some operators add 10 grams of reagent to a l\tei f water, rhis wn produce a one percent solution. One mL of the stock solution in one
liter will produce a ten mg/L dosage.

86 Water Treatment

14.91 Examples

Let's set up some jar tests to determine the optimum
dosages for lime or lime-soda treatment to remove hardness
from a municipal water supply. To get started, add 10.0
grams of hydrated lime to a one-liter graduated cylinder or
flask and fill to the one-liter mark with tap water. Thoroughly
mix this stock solution in order to thoroughly suspend all of
the lime. One mL of this solution (which has t>een thoroughly
mixed) in a liter of water is the same as a lime dose of ten
mg/L, or 0.5 mLin 500 mL is still the same as a ten mg/L hme
dose.

Set up a series of hardness tests by adding 5.0 mL, 10.0
mL, 15.0 mL, 20.0 mL. 25.0 mL. 30.0 mL, 35.0 mL and 40.0
m L to one-liter (1 000 mL) beakers or jars, r ;|| the beakers to
the 1000 mL mark with the water being tested. Mix thor-
oughly for as long as normal mixing will occur in your plant.
Allow the precipitate to settle (20 minutes if this is the settling
time in your plant) and measure the hardness remaining in
the water above the precipitate. A plot of the hardness
remaining against the lime dosage will reveal the optimum
dosage. Examination of Figures 14.8, 14.9 and 14.10^®
reveals that the water of all three cities responded differently
to the increasing lime dosage. City 1 (Figure 14.8) should be
providing a lime dose of 100 mg/L. The cost of increasing
the dosage to 150 mg/L is not worth the slight reduction in
hardness from 110 to 100 mg/L as CaCOg. Note that an
overfeed of lime will actually Increase the hardness.

City 2 (Figure 14.9) should be providing a lime dose of 200
mg/L A dose of 300 mg/L will reduce hardness, but tho
increase in lime costs is too great. City 3 (Figure 14.10)
should be dosing lime between 200 and 250 mg/L. Note that
the greater the lime dose, the less the hardness, but the
greater the quantities of sludge that must be handled and
disposed of.

If lime added to the water does not remove sufficient
hardness, select the optimum lime dose and then add
varying amounts of soda ash. From Figure 14.9 we found
that the optimum lime dose was 200 mg/L (300 mg/L would
have reduced the hardness slightly). Let's take six one-liter
containers and add 20 mL of our lime stock solution (a
dosage of 200 mg/L). Prepare a stock solution of soda ash
similar to our lime solution by adding 10 grams of soda ash
to a one-liter container, fill with distilled water and mix
thoroughly. Add zero, 2.5 mL (25 mg/L dose), 5 mL, 7.5 mL,
1 0 mL and 12.5 mL to the one-liter containers. Mix thorough-
ly, allow the precipitate to settle and measure the hardness
remaining In the water above the precipitate. A plot of
hardness remaining against the soda ash dosage will reveal
the desired dosage. We would like the final hardnes:; to be in
the 80 to 90 mg/L as CaCOg range in this example.

To select the optimum doses of lime and soda ash.
consider the items discussed below.

1 Optimum dosage of lime was based on increments of 50
mg/L. You should refine this test by trying at least two-10
mg/L increments above and below the optimum dose.
From Figure 14.8 we found that 100 mg/L was the
optimum dose. Try lime doses of 80, 90, 100, 110 and 120
mg/L.

2 Optimum dosage of soda ash can be refined by trying
smaller increments also.

3 Try slightly increasing the actual lime dose in your plant to
see if there is any decrease in the remaining hardness. Is
the decrease in hardness worth the increobt? in lime
costs?

4. Try slightly increasing and decreasing both lime and soda
ash dosages at your plant one at a time, and evaluate the
results.

5. If yoj are treating well water or a water of constant
quality, all you have to do to maintain proper treatment Is
to make minor adjustments to keep the system fine
tuned.

6. If you are treating water from a lake or a river and the
water quality (including temperature) changes, you'll have
to repeat these procedures whenever the raw water
quality changes. Water quality changes of concern in-
clude raw water hardness, alkalinity, pH, turbidity and
temperature.

7. REMEMBER, you do not want to produce water of zero
hardness. If you can get the hardness down to around 80
to 90 mg/L, that usually will be low enough for most
domestic consumers. When selecting a target hardness
level for your plant, consider the uses of your softened
water and the cost of softening.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 109.

14 9A What items should be considered when determining
the hardness of the treated water from a water
softening plant?

14.9B If lime added to water does not reduce the hardness
of a water sufficiently, what would you do?

14.92 Calculation of Chemical Feeder Settings

After chemical doses have been calculated or determined
from jar tests, convert the results to plant chemical feed
rates. Depending on the type of chemical feeder, you may
have to calculate the feed rates in pounds per day, pounds
per hour or pounds per m nute. Always feed enough chemi-
cal to achieve the desired results, but don't over feed Over
treating is a waste of money and quality control will suffer.

EXAMPLE 4

The optimum lime dosage from the jar tests is 230 mg/L. If
t;ie flow to be treated is 6 MGD, what is the feeder setting in
pounds per day and the feed rate in pounds per minute?

16 These figures were adapted from an article titled, "Use of Softening Curve for Lime Dosage Control, ' by Michael D Curry ° E vhich
appeared in THE DIGESTER/OVER THE SPILLWA Y, published by the Illinois Environmental Protection Agency. ' '

ERIC 98

90 Water Tri^atment

Known Unknown
Lime Dose. mg/L = 230 mg/L 1 . Feeder Setting, lbs/day
Flow, MGD = 6 MGD 2. Feed Rate, Ibs/min

1 . Calculate the feeder setting In pounds per day

''Ibs/da^y^^^'"^' = MGD)(L,me. mg/L)(8.34 Ibs/gal)
- (6 MGD)(230 mg/L)(8.34 ibs/gal)
= 11,509 lbs/day

2. Calculate the feod rate in pounds per minute.
Feed Rate. ^Feeder Setting, lbs/day

(6u min/hr)(24 hr/day)

n. 509 lbs/day
(60 min/hr)(24 hr/day)
= 8.0 Ibs/min

When the calculated feed rate of e^ght pounds of lime per
minute is put into the plant process, observations and tests
will determine if optimum levels are met. In many instances,
jar tests and actual plant feed rates do not agree exactly.
This Is because of temperature, size and shape of jars vs.
size and shape of plant facilities, mixing time, and Influence
of the coagulant (a heavy alum feed would neutralize more
of the lime). Jar tests are merely Indicators or a point of
beginning.

If underfeeding results, reactions will not be complete and
the results will be undertreated water having a hardness
higher than that desired.

If overfeeding results, chemicals are being wasted. Also, it
IS quite possible to have excessive calcium in the water This
results in unstable conditions which cause buildup on the
sand grains and the interior of the water mams. This is
where the stability test enters the p jture (refer to Section
14.5. "Stability").

The above discussion has cealt with establishing the
proper lime feed. The same process would be used to
determine the soda ash requirements if you are removing
noncarbonate hardness Set up the lime feeds as discussed.
Pick the optimum dosage. Then set up another series of jars
using the same lime feed rate in all jars. Now, vary the soda
ash feed rate.

EXAMPLE 5

How much soda ash is required (pounds per day and
pounds per minute) to remove 50 mg/L noncarbonate hara-
ness as CaC03 from a flow of 6 MGD'?

Known

Unknown

Noncarbonate Hardness ^ cq l Feeder Setting, lbs/

Removed. mg/L as CaC03 ^' day

Flow. MGD - 6 MGD 2 Feed Rate, lbs/mm

1 Calculate the soda ash dose in milligrams per liter. See
Section 14 316. "Calculation of Chemical Dosages" for
the following formula.

Soda Ash. ^ , Noncarbonate Hardness, wi/,"iinn\
mg/L ^ mg/LasCaC03 Mi^Wiuuj

= (50 mg/L)(106/l00)
= 53 mg/L

2. Determine the feeder setting in pounds per day.

^^Ibs/da^^"'"^' " MGD)(Soda Ash, mg/L)(8.34 ibs/gal)
- (6 MOD) 53 mg/L){8.34 Ibs/gal)
= 2652 lbs/day

3 Calculate the soda ash feed rate m pounds per minute.
Feed Rate. ^ Feeder Setting, lbs/day
Ibs/min min/hr)(24 hr/day)

2652 lbs/day

ERIC

105

(60 min/hr)(24 hr/day)
= 1.8 Ibs/min

After you determine the proper feed rates and implement
them, if you are treating well water or other water of
constant quality, all you have to do to maintain proper
treatment is make minor adjustments to keep the system
fine tuned.

On the other hand. If you treat a river or lake supply
subject to constant and frequent changes in water quality.
It's an entirely different set of circumstances. Until you learn
from experience to judge the chemical changes necessary
by the fluctuations in raw water hardness, alkalinity and
tujfc.dity. you almost nave to check yourself daily by the jar
test method.

When your treatment process does not work properly, the
first thing to check is whether or not the feeder is feeding
properly If it is. the next step is to check your source water
quality Generally, one of these two will be the cause of your
problem

QUESTIONS

Write your answers ir. a notebook and thrn compare your
answers with those on page 109.

14 90 Why should the overfeeding of chemicals be avoid-
ed'?

14 9D What should be the lime feeder setting in pounds per
day to treat a flow of ? MGD when the optimum lime
dose IS 160 mg/L'?

14 9E How much soda ash is required in pounds per day to
remove 40 mg/L of noncarbonate hardness from a
flow of 2 MGD'?

Softening 91

DISCUSSION AND REVIEW QUESTIONS

Chapter 14. SOFTENIN^G

(Lesson 1 of 2 Lessors)

At the eno of each lesson in this chapter you will find some
discussion and review questions that you Siiculd work
before continuing. The purpose of these questions is to
indicate to you how veil you understand the material in the
lesson. Write the answers to these questions in your note-
book before continuing

1. Why should water be softened'?

2. What are the benefits of softening water in addition to
hardness removal?

3 Why IS settlea water recarbonated after the precipitation
of calcium carbonate?

4 What are the advantages of using liquid caustic to
soften water?

Why should quicklime never be stored close to cor.nbus-
tible material?

6. How can operators protect themselves from lime'?

7. Why IS the stability of a water important?

8. Why IS a p,iSte-type slaker dangerous?

9. Why should you avoid using the same conveyor or bin

for alternately handling both quicklime and one of the
coagulants containing water, such as alum?

10 Why IS sludge sometimes recirculated back into the
primary mix area of conventional plants?

1 1 When running jar tests, how would you deterr.iine the
optimum dosage for a coagulant, lime and soda ash?

12 When your lime-soda ash softening plant does not
perform properly, what is the first thing you should
check'?

CHAPTER 14. SOFTENING

ion Exchange Softening by Marty Reynolds

(Lesson 2 of 2 Lessons)

14.10 DESCRIPTION OF ION EXCHANGE SOFTENING
PROCESS

The lerm "Zeolite" is most often associ ited with sodium
lon exchangers and snould be considered lO mean the same
as the term ion exchange. Most ion exchange units in use
today use sulfonated polystyrene resins as the exchange
media, lon exchange softening can be defined as exchang-
ing hardness-causing ions (calcium and magnesium) for the
sodium ions that are attached to the ion exchange resins to
create a soft water.

The treatment plant operator should be aware of the three
basic types of softeners on the market.

1 An upflow unit in which the water enters from the bottom
and flows up through the ion exchange bed a^J out the
top

2 A unit which is constructed and operated like a gravity
rapid sand filter The water enters the top, flows down
through the ion exchange bed and out the bottom.

3. The pressure downflow ion exchange softener, which is
the most common will be covered by this chapter. See
Figures 14 11 and 14.12. Pressure filters m../ be either
horizontal or vertical units. Vertical units are preferred
because there is less chance of short-circuiting.

To help explain the construction and activity that occurs in
an ion exchanger, let's compare it to a pressure filter. The
water enters the unit through an inlet distributor located m
the top; it IS forced (usually pumped) down through a bed of
some type of media into an underdrain structure. From the
underdrain structure, the treated water flows out of the unit
and into storage or into the distribution system.

The flow pattern through a filler and r ftener are similar,
the key difference being the action that takes place in the
media or bed of each unit. The filter bed may be considered

1^G

92 Water Treatment

VERTICAL SOFTENER TANK

" DIAMETER

" SIDE SHELL HEIGHT

R&l WR

AIR RELEASE LINE

" FILTER SAND. SIZE TO MM.

" GRADED GRAVEL. SIZE l/4"x*l0
" GRADED GRAVEL. SIZE 1/2" x 1/4"
" GRADED GRAVEL. SIZE 3/4" x 1/2"
"GRADED GRAVEL, SIZE 1 1/2" X 3/4"

UK">ERDRAIN

STANDARD SOFTENER

UNDERDRAIN:-

RWDLY SUPPORTED PLATE OVER ICO %
FLTER AREA WITH STAINLESS STEEL
BAFFLE ASSEMBLIES.

ZEOLITE-

.CUBIC FEET.

SUPPORTING GRAVEL:-.

'GRADED.

STAINLESS STEEL
BAFFLE ASSEMBLY

Figure 14. 1 1 Pressure downflow ion exchange softener

(Permission ol General Filter Company)

ERIC

107

j POWER SUPPLY
tllO VOLT 60 CYCLE
l-PHASE SERVICE

CONTROL PANEL
CYCLE TIMERS

INTERLOCK
BRINE CONTROL

- DIAPHRAGM VALVE
CONTROL LINES

ERLC

Figure 14, 12 Semhautomatic controls for ion exchanger

(Permission of General Filter Company)

in;)

;»

94 Water Treatment

an adsorption and mechanical straining dev.ce used to
remove suspended solids from the water. The bed usually
consists of sand, anthracite (crushed coal) or a combination
of both. Once the bed becomes saturated with the insoluble
material (usually clay, suspended solids and iron manga-
nese hydroxide), the filter is taken out of service, back-
washed and returned to service. This pressure filter will
continue to operate until the condition reoccurs and the
procedure is repeated.

The bed, media or resin in an ion exchange softener,
however, is much more complex. This resm serves as a
medium In which an ion exchange takes place. As hard
water is oassed through the resin, the sodium ions on the
resin are exchanged for the calcium and magnesium ions (in
the case of sodium exchange re^^insi). The sodium ions are
released from the exchange resin and remain in the water
which flows out of the softener. The calcium and magnesium
ions, however, are retained by the resin. The softener
effluent is free from calcium and magnesium ions and
therefore Is softened (Figure 14.13).

Once a softener has exchanged all of its sodium ions and
the res.n is saturatef^ with calcium end magnesium, it will no
longer produce SDft water. At this time the unit must be
taken out of service, the calcium and magnesium removed
trom the res'n by exchange with sodium ions. This process
IS referred to as a regeneration cycle.

In a regeneration cycle, the calcium and magnesium ions
that have been retained by the resin must be removed and
the sodium ions restored. In order for the exchange to take
place, the resm must hold all ions loosely. If the calcium and
magnesium ions cannot be removed, the resm will not
accept the addition of new sodium ions that are necessary
for additional softening

Salt in the form of a concentrated brme solution is used to
regenerate (recharge) the ion exchange resm. When salt is
added to water it changes into or ionizes to form sodium
cation (Na"*") and chloride anions (Cl~). When the brme
solution IS fed into the resm, the sodium cations are ex-
changed for calcium and magnesium cations. As the brine

PLUG FLOW-PISTON EFFECT
HARDNESS APPLIED

Ca^+ Mg++

PLUG FLOW-PISTON EFFECT
HARDNESS APPLIED
Ca^+ Mg+^

Na^

Na-

Na^

[1]

EXCHANGE RESIN
PRIOR TO SOFTENING
(AFTER REGENERATION)

Ca^^

Mg^^

Ca^^

Na^

[2]

Na^ AND SOFT WATER EXCHANGE
RESIN AFTER START OF SOFTENING CYCLE

Ca^^

Mg++

Ca^^

Mg^^

Ca^^

Na^

Ca^^

Na^

[3]

Na^ AND SOFT WATER EXCHANGE
RESIN DURING SOFTENING CYCLE

Mg**

Ca**

Mg**

Ca**

Mg**

Ca**

Mg**

[4]

EXCHANGE RESIN EXHAUSTED
(ALL SOFTENING CAPACITY LOST-
READY TO REGENERATE. SEE [1])

ERIC

Fig. 14.13 Ion exchange resin condition during softening cycle

110

Softening 95

solution travels down through the resm, the sodium cations
are attached to the resin while the calcium, magnesium and
chloride (from the salt) ions flows to waste After the
regeneration has taken place, the bed if ready to be placed
in service again to remove calcium and magnesium by »on
exchange.

QUESTIONS

Write your answers in a notebook and then compare your
answeis with those on page 110.

14.1 OA List the three basic types of softeners on the
market.

14 10B What happens during tfie regeneration cycle of an
ion exchange sofiener?

14.11 OPERATIONS

Many factors influence the procedures usee to operate an
ion exchange unit and the efficiency of the softening proc-
ess. These factors include-

1. Characteristics of the ion exchange resin,

2. Quality of the source v^ater.

3. Rate of flow applied to the softener,

4. Salt dosage during regenerjtion,

5. Bnne concentration, and

6. Brine contact time.

Each ion exchange softener, regardless of manufacturer,
will have at least four common stages of operation. These
stages are listed below and will be explained as each occurs
in the softener operation (see Figure 14.14).

1. Service.

2. Backwash.

3. Brine, and

4. Rinse.

14.110 Service

The service stage of each unit is where the actual soften-
ing of the water occurs. Hard water is forced into the top of
the unit and allowed to flow down through the exchange
resin. As this takes pla je. the calcium and magnesium ions
exchange with sodium on the reoin. The sodium ions are
released into the water and the exchange capacity of the unit
IS slowly exhausted.

The length of each service stage is dependent on several
factors, source water hardr.ess is a mam consideration. The
harder the water, the more calcium and magnesium must be
removed to reach a level of zero hardness. Simply stated,
the harder the water, the less water you can treat before the
resin becomes exhausted. As long as the design flow for the
ion exchange unit is not exceeded, changes in the hardness
of the source water may be automatically adjusted for in the
ton exchange unit. The effluent from the unit usually will have
zero hardness until the unit needs regeneration. If the total
dissolved solids (TDS) in the water supply is fairly high
(above 500 mg/L). there may be some leakage. If a high TDS
water has a high sodium content, the sodium may hinder the
process by causing a local exchange on the media of
calcium and magnesium (hardness leakage) for some of the
sodium The amount of hardness leakage depends on the
TDS and the salt dosage (percent salt) used for regenera-
tion.

Other factors involved are the size of the softener and the
exchange capacity of the resin Softeners can vary in size
from a few cubic feet to several hundred cubic feet. The size
of the unit will generally be consistent with regard to the
overall treatment plant design. In other words, the softener
should be capable of producing enough softened water so
that the mix or blend of softened and upsoftened water will
produce a treated water with the desired level of hardness.

The exchange resin will also vary in its removal capacity.
There are many types of strong acid cation exchange resins
on the market today. Most will range in capacity from 20.000
to 30.000 grains of hardness removal per cubic foot (0.01 1 to
0.016 kg/cu m) resin. The removal ability of the resin is
usually expressed in grains of hardness removal per cubic
foot of material or resin.

The source water hardness, size and the removal capacity
of the resin will determine the amount of water that can be
treated before the softener must be regenerated. Vith a few
Simple calculations, an operator can determine the softening
capacity of the units. Calculations and examples will be
given at the end of the chapter. See Example 8 in Section
14 18, "Ion Exchange Arithmetic."

14.111 Backwash

The second stage of the ion exchange softener process Is
the backwash. In this stage, the unit is taken out of service
and the flow pattern through the unit is reversed. The
purpose of this is to expand and clean the resin particles and
also to free any material such as iron, manganese and
particulates that might have been rem )ved during the soft-
ening stage. The backwash water entering the softener at
the beginning of this stage should be applied at a slow
steady rate If the water enters the unit too quickly, it could
create a surge in the resin and wash it out of the unit with the
water going to waste.

Ideal bed expansion dunng the softener backwash snould
be 75 to 100 percent. In other words, when the unit is
backwashed. the resm should expand to occupy a volume
from 75 to 100 percent greater than when in normal service.
An example of this would be an ion exchange softener with
24 inches (60 cm) of resm whi'e in service. When the unit is
backwashed. the resin should expand to 48 inches (120 cm)
for a 1 00 percent expansion of the bed. As the bed expands
a shearing action due to the backwash water and some
scrubbing action will free any material that might have
formed on the resm particles during the softening stage.

During the backwash a small amount of resm could be
lost. This ^mount, however, should be minimal and you

96 Water Treatment

OPERATIOM

VALVE NUMBER

SERVICE

OPEN

BACK WASH

OPEN

BRINE

CLOSF

OPEN

RINSE

OPEN

Fig. 14.14 Valve positions for each stage
of ion exchange softener operation

(Permission of General Filter Company)

^ • 112

Softening 97

should cfieck the backwash effluent at different intervals to
insure that the resin is not being lost. A glass beaker can be
used to catch a sample of ilie effluent while the unit is
backwashing A trace amount of resin should cause no
alarm, but a steady loss of resm could indicate a probi->m m
the unit and the cause should be located and corrected as
soon as possible. Too much loss of resin may be caused by
an improper freeboard on the tank or wash troughs.

The backwash duration and flow rate will vary depending
on the manufacturer and the type ar j size of resin used and
the water temperature

14.112 Brine

The third stage is most often termed the regeneration or
brine stage At this point, the sodium ion concentration of the
resm is recharged by pumping a concentrated brine solution
onto the resm. The solution is allowed to circulate through
the unit and displace all water from the resm in order to
provide full contact between the brine solution and the resm.

Most treatment plants use a bnne solution to regenerate
their softening units. The optimum brine concentration com-
mg in contact v/ith the ion exchange resm is around 10 to 14
percent sodium chloride solution Concentrated bnne is only
used when the water v thin the softener tank serves as the
dilution water A 26 percent bnne solution (fully concentrated
or saturated) causes too great of an osmotic shock on the
■on exchange resm and can cause it to break up. The salt
dosage used to prepare the brine solution is one of the most
important factors affecting the ion exchange capacity and
ranges nom 5 to 15 pounds of salt per cubic foot (80 to 240
kg/cu m) of resm. See EXAMPLE 10 on page 104 for
procedures on how to calculate the salt dosage and gallons
of brine solution required. Brine concentrations less than
saturated require longer contact time and more solution
must be applied to the unit to achieve a successful regenera-
tion.

The regeneration stage of the softener is very important
and the operator should be certain it is properly carried out.
In the regeneration stage, the sodium ions present in the
bnne solution are exchanged with the calcium and magne-
sium .ons on the resm. The ions on the resm were ex-
changed during the service or softening stage. The regen-
eration rate is usually one to two GPM per cubic foot (2.2 to
4 4 liters per second per cubic meter) of resm for the first 53
minutes and then three to five GPM per cubic foot (6.6 to 1 1
liters per second per cubic meter) for the last five minutes of
fast dram. If the regeneration process is performed correct-
ly, the result is a oed that is completely recharged with
sodium ions and will again soften water when the unit is
returned to service

ERLC

14.113 Rinse

The fourth and final stage of softener operations is ♦he
nnse stage After adequate contact time has been allowed
between the brine solution and resm, a clear rinse is applied
from the top of the unit to remove the waste products and
excess brine solution from the softener. The flow pattern is
very similar to the service stage except that the softener
effluent goes to waste instead of storage. The waste dis-
charge contains high concentrations of calcium and magne-
sium chloride Most rinse stages will last between 20 and 40
minutes, depending on the size of the unit and the manufac-
ture See Section 14. 14. "Disposal of Spent Brine," for
procedures on how to oispose of the waste discharge.

Again, the operator should pay close attention to the
softener while it rinses The rinse must be long enough to
remove the heavy concentration of waste from the unit. If the
rinse is not of the correct length and the unit returns to
service, g salty taste will be very noticeable in the softener
effluent Taste the waste effluent near the end of the nnse
stage to determine if the majority of chloride ions have been
removed. The chloride lon concentration may also be meas-
ured by titration as outlined in Chapter 21, "Advanced
Laboratory Procedures or by measunng the conductivity of
the water If the water still has a strong salty taste or
excessive chloride ions are present, check the nnse rate and
timer settings. The unit may need adjustment to increase the
duration of the nnse stage

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 11^.

14 11A What IS the mam consideration in determining the
length of the service stage of an ion exchange
softener'^

14 11B What IS the purpose of the backwash stage of an
ion exchange softener'?

14 lie How are ion exchange softeners regenerated'?

14 11D Where does the softener effluent go dunng the
nnse stage'?

14.12 CONTROL TESTING OF ION EXCHANGE
SOFTENERS

In most small treatment plants, the operator has to per-
form many jobs and may not always have time to monitor the
softening units js they should be monitored. If a few simple
test procedures are learned and carried out on a regular
basis the operator can ^eel confident the ion exchange units
are operating properly. Control tests the operator should
perform are listed in this section.

1. Softener Influent

Be aware of the iron and manganese levels entering
the softener. These levels should be kept to a minimum to
prevent fouling of the media bed as the unit will remove a
certain amount of iron and manganese before becoming
plugged. Insoluble particles of iron and manganese will
plug the filter media. Soluble ionic iron (Fe^^) and manga-
nese (Mn^^) will exchange onto the media and will not be
fully removed by regeneration. If the source water enter-
ing the plant is high in iron and manganese, proper
oxidation and filtration of the water BEFORE the softener
should reduce the levels and prevent problems from
developing in the softeners.

t 1'3

98 Water Treatment

Monitor source water hardness on a routine basis.
Generally, hardness will not vary, but if it changes, you
Will need to adjust the amount of water treated by each
softener before the media becomes exhaustec' and the
unit must be regenerated

2. Softener Effluent

At the end of a regeneration stage, as the unit goes
back into service, check the effluent for hardness This
one test will tell you if the regeneration of the softener has
been properly conducted. Allow a few minutes to ensure
that all of the rinse vater in the unit has been purged
(removed). Run a hardness test on the effluent side of the
unit. The results should indicate a water of zero hard-
ness. Several test kits are available on the market today
that are fairly quick ar.i simple to use to measure water
hardness.

14.13 LIMITATIONS CAUSED BY IRON AND
MANGANESE

Ion exchange units are very versatile. The primary pur-
pose of the unit is to remove calcium and magnesium from
the water thus making the water soft. Ion exchange soften-
ers, however, will also remove iron and manganese in either
the soluble or precipitated form. If this occurs, the iron and
manganese will seriously affect the life of the exchange
capacity of the resin. If water high in iron and manganese is
applied to the ion exchange resin for very long, iron fouling
or the loss of exchange capacity will result.

When *he softeners remove iron in the ferrous (soluble) or
ferric (solid) form, the two problems discussed below could
result

1 If water with iron In the ferrous form is applied to the
softener, the resin will remove the iron from the water.
The iron can be retained on the surface of the resin or is
sometimes captured deep inside the resin itself. As this
happens, the resin or bed will develop an orange or rusty
appearance. I.' the resin becomes iron coated, the effi-
ciency of the softener will bP reduced greatly.

2. The second problem associated with high iron levels is a
plugging or clogging of the resin bed. When water con-
taining iron in the ferric form (solid) is applied to the unit, it
will act like a filter and strain the iron from the water,
leaving the iron trapped in the bed. If high iron loadings
continue, the upper layer of the bed could become
plugged, forcing the water to channel or short-circuit
through the bed. The result is incomplete contact be-
tween the water and media thus creating hardness leak-
age and loss of softening efficiency.

IRON AND MANGANESE MUST BE REDUCED TO
THEIR LOWEST POSSIBLE LIMITS BEFORE APPLYING
WATER TO THE SOFTENER. Oxidation of iron and
manganese (see Chapter 12. "Iron and Manganese Con-
trol") BEFORE applying water to ion exchange units is
very helpful. You should also be aware of the chlorine
levels applied to the softening units Normal chlorine
dosages will not present a problem, but high residuals
could damage the resin and reduce its life span.

14.14 DISPOSAL OF SPEN"^ BRINE

One of the larg'^st problems associated with the design
and operation of ion exchange softening plants is the
disposal of the softener waste.

The waste discharge from softeners consists mostly of
calcium, magnesium and sodium chlorides. These by-prod-
ucts are corrosive to material they contact and possess
varying ;oxic levels in relationship to the environment.

Many water treatment plants discharge spent brine into
nearby sewers This procedure may be approved if the
downstream wastewater treatment plant and receiving wa
ters can handle the brine. Usually the water treatment plant
must have some type of holding tank to store the spent
bnne The brine is slowly discharged into the sewer at a rate
which will not upset (or be toxic to) the biological treatment
processes at the wastewater treatment plant Also the salt
level in the effluent from the wastewater treatment plant
must not adversely impact the aquatic life in the receiving
waters nor cause a violation of the wastewater treatment
plant's NPDES PERMlT^"^

Some water treatment plants mcy be issued an NPDES
Permit to discharge spent brine into receiving waters. This
could happen only if the flow in the receiving waters was
very high (plenty of dilution) and the flow of spent brine was
very low A holding tank would be needed for the spent brine
and the bnne could be discharged very slowly. The receiving
waters would have to be monitored to be sure that the
discharge of bnne will not cause a significant increase m the
level of bnne

Sanitary landfills also may be an acceptable means of
disposing of spent bnne See Chapter 17. 'Handling and
Disposal of Process Wastes." for additional information.

Each lon exchange treatment plant probably has only one
approved method of waste disposal. Very few options are
available to plants discharging this type of waste. Alternate
waste disposal methods available for spent bnne are cov-
ered in Chapter 17. "Handling and Disposal of Process
Wastes '

^7 NPDES Permit, national Pollutant Discharge Bhmination System permit is the regulatory agency document issued by either a federal or
state agency which is designed to control all discharges of pollutants from point sources m U,S, waterways, NPDES permits regulate
discharges into navigable waters from all point sources of pollution, including industries, municipal treatment plants, large agricultural
^ feed lots and return irrigation flows.

ERIC

Softening 99

The operator needs to ',2 aware of the seriousness
involved with softener waste. If a problem develops at the
treatment plant, the operator should be working with the
agency in the area that governs waste disposal as several
considerations must be studied when changsng a disposal
method

QUESTIONS

Write your answers in a notebook and then compare your
ansvi/ers with those on page 110.

14 12A Which water quality indicators should be monitored
in the effluent of an ion exchange softener*?

14 13A What happens when high chlorine residual levels
are applied to the softening units'?

14.14A Why is the disposal of spent brine a problem*?

14.15 MAINTENANCE

Most of the ion exchange water softening equipment on
the market today is fully automated (Figure 14.12). The
reason for most of this automation is to reduce the time an
operator must spend with each unit. Automation is fine for
operational control, but it does not mean a unit is mainte-
nance free. Systems like this have a tendency to lead
operators astray. A smail routine maintenance item can go
unnoticed until it becomes a full scale problem if the opera-
to* does not run a regular maintenance schedule on the
equipment. For example, most valves on ion exchange units
arc pneumatic or are equipped witn some type of self-
operating device (valve actuators). This does not mean,
however, the valve will operate each time it is required to do
so A'.thout a regular examination and overhaul. The operator
must check the equipment to insure it is always in proper
working order One valve that fails to open or to close dunng
a regeneration stage could mean trouble (a storage tank full
of salty water or no brine at all;.

The components of an ion exchange softening system
that should receive constant attention are the brine pumps
and piping. A saturated brine solution is very corrosive and
will attack any unprotected metallic surface it comes iri
contact with. Try to keep the system as tight as possible. An
uncontained brine leak will only get worse.

If you must change the pipe work in the brine system, give
serious consideration to installing PVC pipe. The material is
much cheaper than bronze and will outlast steel or galva-
nized pipe when properly installed and supported. Future
repairs are also much easier to make if PVC pipe is used.

The pun^p on the brine system is most often made of
brass which offers some additional protection from the bnne
solution. The impeller should be bron7e and the shaft
stainless steel. A strainer or screen oevice should be in-
stalled ahead of the pump on the suction side.

Most treatment plants buy salt to make their brine solution
in bulk form. Regardless of the salt supplier, a certain
amount of insoluble material will accompany each bulk
delivery This insoluble material will consist of rocks, coal,
sand and other particles that can clog or destroy an impeller
if they reach the pump. Check the strainer assembly on the
brine pumps quite often and keep spare parts on hand in
case replacement is required.

The use of packing on the pumps is recommended over
mechanical seals. Regardless of how well the strainers
perform, a small amount of sand will usually end up in the

pump The combination of sand and mechanical seals will
most often result in high repair and mu"^tenance costs
Packing is v^heaper and easier to install and maintain than
mechanical seals and packing wil! usually outlast mechani-
cal seals in this type of mstanation

The brine pump motor should have a 'heavy duty " rat'rig
and a body made of cast iron is preferable. Aluminum or mild
steel motor housings do not hold up as well as cast iron
when subjected to the corrosive environment around the
brine pumpmg station.

An f.rea most often neglected until problems arise is the
bulk brine storage area of the treatment plant. Most storage
areas are underground pits equipped with rock or gravel
strainers above some type of underdram collection system.
Over a period of time, the strainers will si;t in with sand and
impunties received with salt deliveries. The best way to
prevent this from occurring is to regularly shut down, dram
and replace the strainer systems in the pit. This is a great
deal of work, but it is a necessity if the brine system is to stay
in operation.

Some brine storage areas have become so clogged that
the bnne solution could not penetrate the strainer media and
reach the underdram system. Like the head loss on a filter,
the strainers can become so clogged that the solution
cannot seep through to the underdram system. If this
happens and the system cannot be shut down for cleaning, a
pipe can be driven down through the sand and impurities
into the gravel layers. If enough holes are driven through the
zones of impurities, the solution will eventually seep into the
underdrains and caii be pumped into the softeners. This is a
temporary repair measure only and th"* storage area should
be cleaned as soon as possib'<?.

Inspect the brine solution make-up water line while the
storage area is shut down. This line must be kep* in good
working order because it provides potable wate^ to the salt
supply This water makes the saturated brine solution that is
used to regenera'i^ the softener PVC pipe would provide
excellent service in a corrosive environment such as a
storage area.

Wet salt storage bnne tanks are another location at a
water treatment plant where sanitary defects may develop.
The make-up water line must have a free fall or air gap
someplace in the system to prevent the backflow of a brine
solution into the potable water supply. The brine tanks must
be protected from contamination just like any other water
storage facility. The cover and access hatches must be of
the raised-lip, overlapplng-cover type. All vents must be
properly screened to keep out insects, birds, and rodents.

I t fr
1 * i)

100 Water Treatment

All areas of maintenance tn an ion exchange softenmg
plant cannot be covered here because each plant will differ
With the type of equipment used and its method of operation
Set up a maintenance routine that is characteristic of your
treatment plant The objective of the maintenance routine
must be to keep the plant operating and hold repair costs to
a minimum

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 110.

14 ISA What could happen if a valve fails to open or close
during a regeneration stage'?

14 15B Why should the brme pumps and piping receive
constant aiteiit'on'?

14 15C Why IS packing on bnne pumps recommended over
mechanical seals'?

14.16 TROUBLESHOOTING

14.160 Test Units

Ion exchange softeners, if properly operated and main-
tained, will usually provide years of trouble-free service. If
problems ansa however, the operator should be able to
identify and correct the situation without a great deal of
difficulty.

The best way to insure that a softener will continue to
operate properly is to occasionally test the unit during
various stages of operation Learn to recognize minor
problems as they develop and make the necessary repairs
before a full scale problem exists

Items an operator shcjid check on in each stage are
discussed in this section

14.161 Service Stage

In the service stage, while the unit is producing soft water,
hardness tests shoulc' be run on the softener effluent to
insure the water has a hardness of zero. One grain hardness
per gallon of water (17 1 mg/L) showing up in the effluent
should not cause alarm, but concentrations of hardness
higher than one gram hardness per gallon signal the need to
investigate the softener s operation more closely.

14.182 Backwash Stage

Check the backwash stage for adequate flow rates and
full extent of the time required to complete the stage Unless
the rate is high enough to remove trapped turbidity particles
and other insoluble matenal that is trapped in the resin, a
loss of softener efficiency could result

Check the timer on the backwash star ..to make sure the
unit IS washed for the required length of time.

If high iron concentrations have been applied to the
softener, check the condition of the resin by visually inspect-
ing the top layer of the bed Color is a key factor to watch for
in units beginning to show signs of an iron-fouled resin. The
resin will be an orange, rusty color, while the backwash
effluent will appear a light orange at the end of the backwash
stage Also, the head loss on the unit will run higher than
normal as the bed becomes plugged with iron.

If iron fouling appears to be a problem, the length of the
backwash stage should be increased to wash as much of

the particulate matter from t' ) resin as possible. A means of
surface washing the resin must be provided for this proce-
dure to be effective Avoid exceeding recommended manu-
facturer s flow rates to prevent washing resin from ihe unit

A chemical cleaner can be used to remove heavy iron
coalings from the resin itself. These cleaners are mostly
sodium bisulfite and can be mixed in solution form and
poured into the softener. The bisulfite could also be added to
the resin during the regeneration stage by dumping a
concentrated powder form in with the bnne solution. Consult
the resin supplier or manufacturer before using any cleaner
on the resin

14.163 Rinse Stage

The nnse stage of the softener should be checked when
tests indicate problem*^ are developing. The rinse rate is a
key factor in keeping th,. soft^^er functioning properly. If the
nnse starts too soon, the bnne solution could be forced out
of the unit before adequate contact time has elapsed. If the
nnse rate is too low. all the waste matenal might not be
removed from the unit before it goes into the service stage.

The rate settings on the unit should be compared, on all
stages, against the actual manufacturer s recommended
settings As equipment ages, it wears. Over a penod of time,
valves might need adjustment to keep the unit operating
within the manufacturer's guidelines.

14.164 Brine Injection Stage

The bnne injection stage of the softener sequence must
be correctly applied or the unit will not perform satisfactorily
when It returns to service. If the resin is not regenerated
dunng this stage, there will be no sodium ions to exchange
with the hardness ions in the water when the water is applied
to the unit

The bnne storage area should always contain enough salt
to provide a bnne so'ution when make-up water is added.

Also check the amount of salt solution that is pumped into
the softener This is usually done with a meter that is preset
to deliver the exact amount of bnne solution required to
regenerate the softener. If a bnne solution is less than
saturated, longer contact time is required between the
media and the solution

Softeninc 101

The required amount of solution must be delivered consis-
tently to achieve a successful regeneration of the unit. If
hardness leakage appears early in the service or softening
stage, check the amount and saturation of bnne solution in
the bnne system since these are the mam reasons for
hardness leakage.

If hardness leakage is excessive Immediately following a
regeneration stage, shut the unit down and check the media
level. The bed could bP disrupted from excessive backwash
or rinse rates. Iron fouling could also cause a channeling
condition to occur and cause the water to short-circuit
through the media without contacting the corrplete bed
volume.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 110.

14.16A What IS the maximum hardness level expected in
the effluent of a properly operating ion exchange
softener before the operator should investigate the
operation?

14.16B What IS the purpose of the backwash sta^e of an
ion exchange softener operation?

1 4.1 6C What problems may occur If the nnse rate starts too
soon or is too slow?

14 16D What would you do if hardness leakage is exces-
sive immediately following a regeneration stage?

14.17 STARTUP AND SHUTDOWN OF UNIT

At times It becomes necessary to shut a unit down and
take It out of service for repairs or inspection. If the operator
will follow common sense guidelines, no problems should
arise from unit shutdowns.

When dealing with these units, drain and fill them slowly.
This will prevent surging of the media v/hich will either wash
it out of the unit or disrupt it, thus making the media uneven
and creating channeling problems. If you suspect problems
with a unit, the last thing you want to do is make the situation
worse by rapidly backfilling or backwashing the softener.

Most units are equipped with automatic air release valves
(Figure 1 4.1 5). Be certain these valves are operating proper-
ly, because the venting of trapped a'r is an Important step in
filling a unit after it has been shut down.

During unit shutdown, make a complete visual inspection.
Now is the time to detect and correct minor problems that
might otherwise develop into bigger ones. Check the brine
inlet distnbutors while the unit is down. They should be
visible from the top hatch on most softeners.

Make sure the pipe work is level and the nozzles or
openings are not clogged. The distnbutors play an important
role In the regeneration stage by applying the brine solution

evenly to the top of the resin bed If the pipe work is
deteriorating from the bnne solution. PVC pipe should be
used as a replacement.

If the resin and gravel support material is removed from
the softener, check the underdrain structures in the unit and
repair any problems you discover. In filling the unit with
gravel and resin, each zone of the bed should be leveled and
Sized according to manufacturer's specifications.

The procedure for filling a unit with water after a total
shutdown is very important. The flow into the unit should be
from the bottom at a slow, controlled rate- This is done by
putting the unit in the backwash position, running water into
the unit from the bottom and out the ba;Kwash effluent
valve. The purpose of this procedure is to fill the unit with
water and purge the air that was trapped in the resin and
softener during the replacement process.

After the unit is filled the backwash rate should be
increased to normal and continued until the effluent is clear.
Again, care should be taken when bnnging the rates up to
the manufacturer's recommendations, to prevent disrupting
or displacing resin from the bed.

Once the unit has been satisfactorily backwashed, the bed
should be regenerated. This can be accomplished by run-
ning the softener through a normal brine and rinse proce-
dure before it is retumed to service. Run a hardness test on
the effluent to insure all stages have performed correctly
and the unit is softening water.

QUESTIONS

Write your answers \[t a notebooK and then compare your
answers with those on page 110.

14.1 7A Why must ion exchange softeners be drained and
filled slowly during startup and shutdown?

14.178 What should be done if the pipe work in an ion
exchange softener is detenorating from the bnne
solution?

14.18 ION EXCHANGE ARITHMETIC

Hardness is usually expressed as mg/L of CaCOj. In ion
exchange softening, however, hardness is most often ex-
pressed in terms of grains per gallon or grains of hardness
removed from the water being treated.

The exchange capacity of most softeners is expressed as
kilograms (1000 grams) of hardness removed per each cubic
foot of resin.

1\7

102 Water Treatment

AIR RELEASE ASSEMBLY

Pressure aeration and pressure filtration type filtei- plants require an automatic air release
assembly to prevent accumulation of an excessive volume of air :n the pressure filter tanks.
This air release assembly consists of an automatic air release valve, and necessary pine,
valves and fittings to install on filter tank. The air release valve is a float operated type and
must be installeJ with center hne of valve level with or above top oi filter tank. Air from top
of filter enters air release valve at top connection and water from filter inlet pipe enters
valve at bottom connection. Excessive air from filter fills valve body with air forcing water
level down and thereby allowing float to drop, Dowu/i^rd movement of float allows excessive
air to escape through the needle valve until an air-water pressure balance is restored.

In normal operation valves 1 and 3 are open and valve 2 is closed. To flush air release valve
close valve 1 and open valve 2 which allows water from top of filter to flush down through the
valve to the drain. Valve 3 is left open at all times unless it is necessary to remove air re-
lease valve.

Figure. 14. 15 Air release assembly

f'*ermission of General Filter Company)

m ■ lis

Softening 103

Salt in solution form is used to regenerate ion exchange
softeners. The theoretical salt requirement is 0.17 pounds of
salt for 1000 grains of hardness removed. Most regenera-
tions, however, require 0.3 to 0.5 pounds of salt per 1000
grains of hardness removal.

In this section you will learn how to calculate the volume of
the brine solution required to regenerate the softening unit
as well as the pounds of salt required for regeneration. The
concentration of brine solution used at each treatment plant
may vary. Table 14.6 lists the pounds of salt present in the
percentage of brine solution being used.

FORMULAS AND CONVERSION FACTORS

Hardness is usually expressed as milligrams of hardness
per liter of water as CaCOj.

Treatment for hardness Is often discussed as grains of
hardness per gallon of water.

1 gram per gallon = 17.i milligrams per liter

or 1 gpg = 17.1 mg/L

7000 grains = 1 pound

To convert grains per gallon to milligrams per liter,

Hardness, mg/L = (Hardness, grains/gallon)(17.1 mg/L)

1 gpg

To convert milligrams per liter to grains per gallon,

Hardness, ^(Hardness, mg/L)(1 gpg)
grains/gallon 17.1 mg/L

To find the exchange capacity of a softener, you need to
know the removal capacity of the softener in grains per cubic
foot of resin or in kilograins per cubic foot of resin and the
volume of the resin in cubic feet.

TABLE 14.6 SALT SOLUTION CHARACTERISTICS

Percent NaCI
or grams per

Lb$NaCI LbsNaCI

0 grams of

Specific Gravity

Salameter

per

solution

at15**C or 59**F

Degree

U.S. gal

Cu Ft

1.0

1.0073

0.084

0.63

1.0140

0.169

1.27

3.0

1 0217

0.255

1.91

4.0

1.0290

0 343

2.57

5.0

1 0362

0 432

3.23

6.0

1.0437

0.522

3.90

1.0511

0.612

4.59

8.0

1.0585

0.705

5.28

1.0659

0.799

5.98

100

1.0734

0.874

6.69

11.0

1.0810

0.990

7.41

120

1 0885

1.09

8.14

13.0

1.0962

1.19

8.83

14.0

1.1038

1 29

9.63

15.0

1.1115

1.39

10.4

16.0

1.1194

1 49

11.2

170

1.1273

1.60

12.0

18.0

1.1352

1.70

12.7

19.0

1.1432

1.81

13.5

20.0

1.1511

1.92

14.4

21.0

1.1593

2.03

15.2

22.0

1.1676

2.14

16.0

23 0

1 1758

2.25

16.9

24.0

1.1840

2.37

17.7

25.0

1.1923

2.48

18.6

26.0

1.2010

2.60

19.5

26.4

1.2040

100

2.65

19.8

^gralns^^ ^^^^^ '^ ^ (Removal Capacity, grams/cu ft) (Media Vol, cu ft)

water Treated Exchange Capacity, grams

9a' Hardness Removed, grams/gal

Operating Time, hr (Water Treated, gal) (24 hr/day)

ZIbZ::^ ^ AveDa.,yF.ow.ga,/.ay

generation)

To deternme the amount of salt required for regeneration,
you need to know the pounds of salt per 1000 grains
required for regeneration. To calculate the gallons of brine
required for regeneration, you need to know the percent
brine solution or the pounds of salt per gallon of brine.

Salt Needed
lbs

erme.
gallons

(Salt Required, lbs/1000 gr) (Hardness Removed, gr)
Salt Needed, lbs

Salt Solution, lbs salt/gallon of brine

EXAMPLE 6

How many milligrams of hardness per liter are there In a
water with 16 grains of hardness per gallon of water?

Known Unknown

Hardness, gpg = 16 gpg Hardness, mg/L

1 Calculate the hardness of the water in milligrams per liter.

(Hardness, grams/gallon) (17.1 mg/L)

Hardness. mg/L=- : ; —

1 gram/gallon

06 grams/gallon) (17 1 mg/L)

1 grain/gallon

" 274 mg/L

EXAMPLE 7

Convert the hardness of a water at 290 mg/L to grains per
gallon

Known Unknown

Hardness. mg/L = 290 mg/L Hardness, grams/gallon

1. Convert the hardness from milligrams per liter to grains
per gallon

Hardness, ^ (Hardness mg/L) (1 gram/gallon)
grams/gallon 17.1 mg/L

^ (290 mg/L) (1 grain/gallon)

17.1 mg/L
= 17 grams/gallon

EXAMPLE 8

An ion exchange softener contains 50 cubic feet of resin
with a hardness removal capacity of 20 kilograins per cubic
foot of resin. The water being treated has a hardness of 300
mg/L as CaCOj. How many gallons of water can be softened
before the softener will require regeneration?

Known

Resin Volume,
cu ft

ERLC

Removal Capacity,
gr/cu ft

Hardness. mg/L

I!, 9

50 cu ft
20,000 grains/cu ft
300 mg/L

Unknown

Water Treated, gal

104 Water Treatment

1 Convert the hardness from mg/L to grains per gallon
Hardness. ^ (Hardness mg/L) (1 gram/gallon)

grams/gallon ^7 ^ ^g^^

_ (300 mgIL) (1 grain/gailon)

17.1 mg/L
- 17 5 grams/gallon

2 Calculate the exchange capacity of the softener in grams

fc. change (Resm Vol cu ft) (Removal Capacity grams/cu ft)
grau^s'^^ (50 cu it) (20 000 grams/cu ft)

1 .000 000 grains of removal capacity

3 Calculate the volume of water in gallons that may be
treated before regeneration

water Treated, qal = ^^change Capacity, grams

4. rmd the length of time the softeners can run before
requiring regeneration.

Hardness, grams/gallon
1.000.000 grams

17.5 grams/gallon

- 57.143 gallons

Therefore. 57.C00 gaiions of water with 17.5 grams of
hardness per gallon of water can be treated before the resm
becomes exhausted

EXAMPLE 9

An ion exchange softening plant has two softeners that
are eight feet in diameter and the units have a resin depth of
SIX feet. The resin has a 20 kilogram removal aUiiity. How
many gallons of water can be treated if the hardness is 14
grains per gallon? If the flow rate to the softeners is 500
gallons per minute, how long will they operate before
regeneration is required'?

Known Unknown

Nuiiiber of Softeners = 2 Softeners i. Water
Diameter, ft = 8 ft Treated, gal

Resin Depth, ft = 6 ft 2. Operating

Exchange Capacity, = 20,000 grams/cu ft
gr/cu ft

Hardness, = 14 grams/gallon
grain/gallon

Flow, gallons/mm = 5OO gallons/mm

1. Calculate the total volume of softener media

Resm Vol. = (0.7b5)(Diameter. ft)2(Depth. ft)(No. Softeners)
cu ft

= (0.785)(8 ft)2(6 ftX2 Softeners)
= 603 cu ft

2. Calculate the total exchange capacity of the two soften-
ers in grains.

Exchange = (Resm Vol, cu ft)(Removal Capacity, grams/cu ft)
Capacity,

grams (603 cu ft)(20.000 grams/cu ft)

= 12,060.000 grams, removal capacity of the beds

3. Calculate the volume of water in gallons that may be
treated before the resin is exhausted.

Water Treated, .Exchange Capacity, grains

Hardness, grains/gallon

^12,060,000 grains

14 grains/gallon

= 861.429 gallons can be treated before
resin is exhausted

ERIC

operating Time,
hr

(V\/ater Treated, gal)

(Ave Daily Flow. gal/min)(60 min/hr)

(861.429 gal)
(500 gal/min)(60 min/hr)

^ 28 7 hours of operation before regeneration
IS required

EXAMPLE 10

An ion exchange soften<3r will remove 1.000,000 grams of
hardness before the resm becomes exhausted. If 0.3
pounds of salt are required per 1000 grains of hardness,
how many pounds of salt are needed'? If a 15 percent salt
solution IS used to regenerate the unit, how many gallons of
brir e are required? Table 14.6 indicates that 1.39 pounds of
salt is present in each gallon of 15 percent brin^ solution.

Unknown

1 Salt Needed, lbs

2 Brme. gal

Known

Hardness Removal, ^ 1,000,u00 grams
grains

Salt Required. = c.3 lbs/1000 gr
lbs/1000 gr

Salt Solution. - 1.39 lbs/gal
lbs/gal

1 Determine the pounds of calt needed for regeneration.

Salt Neoded- = (Salt Required, lbs/1000 gr)(Hardness Removed, gr)
lbs

^ (0 C lbs Sait)( 1,000.000 grams)

(1000 grains)
^ 300 lbs of salt
2. Find the gallons of brine solution required.

Brine, gal =.

Salt Needed, lbs

Salt Solution, lbs/gallon of brine

= 300 lbs of Salt

1 .39 lbs of falt/gallon of brine

= 216 gallons of brine

(15 percent salt solution)

120

Softening 105

EXAMPLE 11

Use the same information as in Example 10, except use a
12 percent brine solution. Table 14.6 mdicates that 1.09
pounds of salt aie present in each gallon of 12 percent brine
solution. Three hundred pounds of salt are naeded for
regeneration. How many gallons of 1 2 percent brine solution
IS required'?

Known Unknown

Salt Needed. 300 lbs Bnne, gal

lbs

Salt Solution, = 1 .09 lbs/gal
lbs/gal

1. Find the gallons of brine solution required.

Salt Needed, lbs

Brine, gal =_

Salt Solution, lbs/gallon of brine
^ 300 lbs

1.09 lbs/gal
= 275 gallons of 12 percent bnne solution

NOTE: More gallons of bnne solution are required when
using a 12 percent bnne solution than when using a
15 percent solution. The weaker concentration re-
quires more gallons to achieve the same results.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 110.

14.18A A source water has a hardness of 150 mg/L as
CaCOj. What is the hardness in grains per gallon'?

1 4 1 88 An ion exchange softener contains 60 cubic feet of
resin with a hardness removal capacity of 25 kilo-
grams per cubic foot of resin. The water being
treated has a hardness of 250 mg/z. as CaCOj. How
many gallons of water can be softened before the
softaner will require regeneration'^

14.19 BLENDING

Ion exchange softeners will produce a water with zero
hardness Water with zero hardness must not be sent into a
distribution system. Water with zero hardness is very corro-
sive and ovjr a period of time will attack steel pipes m the
system and create red water problems. Also, to provide a
water supply with zero hardness water would be very
expensive.

At most softening plants, the zero hardness effluent from
the softeners is mixed with filtered water having a known
hardness concentration. In other words, a certain amount of
water the treatment plant produces will bypass the softening
units (sp»it treatment). This water has a known hardness
concentration and is mixed in various proportions with the
softener effluent to arrive at a desired level of hardness In
the finished water (Figure 14.16).

An example would be a treatment plant that has a filtered
water hardness of 16 grams/gallon. If the desired plant
effluent hardness is 8 grams/gallon, fifty percent of the plant
influent must be softened and tne other fifty percent would
be filtered water mixed together with the softener effluent.
The result would be water that has a hardness of 8 grains
per gar jn.

The blending of water is very simple and is usually
controlled by a valve and meter. The operator adjusts the
exact gallons per minute bypassing the softener to produce
the desired hardness

UNSOFTENED WATER

FLOW CONTROLLER

BY PASS METER
OPTIONAL

ADJUSTABLE

ORIFICE

SOFTENER

CONTROL
LINE

BLENDED WATER

FIXED
ORIFICE

Fig, 14, 16 Automatic softener bypass

(Permission of Goneral Filter Company)

106 Water Treatment

FORMULAS

To calculate the bypass flow in gallons per day to blend
water, determine the total flow, the filtered water hardness
and the desired effluent hardness.

The softener capacity in gallons and both the softener and
bypass flows In gallons per day are needed to determine the
volume of bypass water.

The total flow produced by the plant before legeneration
IS the sum of the (lows through the softener and the bypass
flow.

Bypass Flow, GPn = C'o^Q^ ^'o^. GPD)(Piant EffI Hardness, gpg)

Filtered Hardness, gpg

Bypass Water, gal ^ (Softener Capacity. gaQjBypass Flow. GPP)

Softener Flow. GPD
Total Flow, gal - Softene*- Capacity, gal -f Bypass Water, gal

EXAMPLE 12

A softener plant treats 120,000 gallons per day. The
filterea water has a hardness of .5 grains per gallon (256
mg/L) and the desired hardness in the plant effluent is 5
grains per gallon (86 mg/L) How much water in gallons per
day must bypass the softener to produce the desired level of
hardness'?

Known Unknown

Total Flow. GPD = 120,000 GPD Bypass Flow,

Filtered Hardness, gpg = 15 gpg GPD
EffI Hardness, gpg = 5 gpg

1. Calculate tne bypass flow in gallons per day.

Bypass Flow, GPD (Total Flow. GPD)(Piant Effi Hardness, gpg)
Filtered Hardness, gpg
^ (120.000 GPD){5 gpg)

05 gpg)

= 40.000 GPD

EXAMPLE 13

Using the information in Example 12, how many gallons of
water will be bypassed before the softener requires regen-
eration? The softener has the capacity to treat 105,000
gallons. From Example 12 the bypass flow is 40.000 GPD
and the total flow is 120,000 GPD. Therefore the softener
flow IS 80.000 GPD (120,000 GPD - 40,000 GPD). What is
the total flow produced by th<5 plant per regeneration?

Known Unknown

Softener Capacity. = 105,000 gal 1. Bypass Water, gal
gal

2. Total Flow, gal

Softener Flow. GPD = 80,000 GPD

Typass Flow, GPD = 40.000 GPD

1, Calculate the gallons of water that will be bypassed
before the softener requires regeneration.

Bypass Water. _ (Softener Capacity, gal) (Bypass Flow. GPD)
93' " (Softener Flow. GPD)

(105.QCJ gal) (40.000 GPO)
80,000 GPD
= 52.500 gallons

ERIC

2 Determine the total flow produced by the plant per
regeneration.

Total Flow, gal = Softener Capacity, gal h Bypass Water, gal
= 105.000 gal + 52,500 gal
- 157.500 gallons

14.20 RECORDKEEPING

Keeping correct and up-to-date records is as important as
performing scheduled maintenance on a regular routine. The
recordkeeping system should be set up to record data on a
daily basis. Record the total flow through the softener each
day, along with the blend rates and gallons that have
bypassed the unit. The total gallons of brine used each day,
along with the pounds of salt used to keep the ion exchange
softener in good working order should be recorded. Records
of the tests performed on the softeners should be kept up-
to-date in order to warn the operator of any problems that
might be developing with the softening unit. Good records
are an impclant part of a successful treatment plant oper-
ation Many problems can be avoided or solved with an
adequate recordkeeping system if you review your daily
records and compare them with the normal recoids to
determine operating problems.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 111.

14.19A Why is source water blended with the effluent from
an ion exchange softener'?

14.20A What records should be koDt by the operator of an
ion exchange softening plant'?

14.21 ARITHMETIC ASSIGNMENT

Turn to the Appendix at the back of this manual on "How
to Solve Water Treatment Plant Arithmetic Problems." In
Section A.52, "Softening," read the material, work the exam-
ple problems and check the arithmetic using your calculator.

14.22 ADDITIONAL READING

1 NEW YORK MANUAL Chapter 1 1 , "Softening."

2 TEXAS MANUAL, Chapter 1 1 , Special Water Treatment
(Softening and Ion Exchange).

3 /VOTES ON WATER CHEMISTRY, prepared for "Ad-
vanced Water Works Operations," by Michael D. Curry.
P E , President Curry and Associate Engineers, Inc., P.O.
Box 246, Nashville, Illinois 62263.

Softening 107

14.23 ACKNOWLEDGMENTS

Portions of the materia! discussed on ion exchange soft-
ening came from the sources listed below.

1. Bowers, Eugene, "Ion Exchange Softening" in WATER
QUALITY AND TREATMENT 3rd Ed., American Water
Works Association, Computer Services, 6666 W. Quincy
Ave., Denver, Colorado 80235. Order No. 10008. Price,
members, $41.00; nonmembers, $51.00

2. Lipe, LA. and M.D. Curry, "Ion Exchange Water Soften-
ing," a discussion for v /ter treatment plant operators,

1974-75 seminar series sponsored by Illinois Environ-
mental Protection Agency, and

3. Riehl, Merrill L., WATER SUPPLY AND TREATMENT,
National Lime Association, 3601 North Fairfax Drive,
Arlington, Virginia 22201. Price, $10.00.

DISCUSSION AND REVIEW QUESTIONS

Chapter 14. SOFTENING

(Lesson 2 of 2 Lessons)

Write the answers to these questions in your notebook
before continuing with the Objective Test on page 111. The
problem numbering continues from Lesson 1.

13. What happens in the resin or media in an ion exchange
softener during the softening stage?

14. How would you insure that large amounts of resin are
not being lost during ihe backwash stage'^

15. How would you determine if an ion exchange softener
rinse stage has been successful

16. What happens if an ion exchange softener removes iron
■n the ferrous (soluble) or ferric (solid) form?

17. What types of insoluble material may be found in salt?
What problems can be caused by this ma'enal and how
can these problems be prevented'^

18. How would you prevent the strainers under the bulk
brine sto'age area from silting in with sand and impuri-
ties'?

19. How would you determine if iron has fouled the resin of
an ion exchange softener'?

20. How are ion exchange units filled with water after total
shutdown'?

21 Why IS water with zero hardness not delivered to
consumers'?

SUGGEST

Chapter 1

ANSWERS TO QUESTIONS IN LESSON 1

Answers to questions on page 72.

14 OA Hardness is caused mainly by the calcium and mag-
nesium ions in water.

14 1A Excessive hardness is undesirable because it
causes the formation of soap curds, increased use of
soap, deposition of scale in boilers, damage in some
industrial processes, and sometimes may cause ob-
jectionable tastes in drinking water.

14.1^ Limitations of the ion exchange softening process
include (1) an increase in the sodium content of the
softened water and (2) ultimate disposal of spent
brine and rinse waters.

Answers to questions on page 75.

14.2A Hardness is commonly measured by titration. Individ-
ual divalent cations may be measured by using an
atomic adsorption (AA) spectrophotometer.

ERLC

I ANSWERS

SOFTENING

14 2B Determine the total hardness as CaC03 for a sample
of water with a calcium content of 25 mg/L and a
magnesium content of 14 mg/L

Known Unknown

Calcium, mg/L = 25 mg/L Total Hardness,
Magnesium, mg/L = 14 mg/L mg/L as CaCOj

Calculate the total hardness as milligrams per liter of
calcium carbonate equivalent.

Total Hardness.^ Catcium Hardness.^ Magnesium Hardness,
mg/L as CaC03"^ mg/L as CaC03 mg/L as CaCOo

= 2 50 (Ca, mg/L) f 4 12 (Mg. mg/L)

- 2 50 (25 mg/L) + 4 12 (14 mg/L)

= 62,5 mg/L + 57,7 mg/L

= 120 2 mg/L as CaCOa

14.2C Water treatment chemicals which lower the pH when
added to water include alum, carbon dioxide, chlo-
rine (CIg), ferric chloride, hydrofluosilicic acid and
sulfuric acid.

loo

1 O

108 Water Treatment

14.2D Results from alkalinity titrations on a sample of water
were as follows:

Known

Sample Size, mL =100 mL

mL titrant used to pH 8 3, A = 1 .2 mL
Total mL of titrant used, B = 5 6 mL
Acid normality, N = 0.02 N H^SO^

Unknown

1. Total Alkalinity, mg/L as CaCOj

2. Bicarbonate Alkalinity, mg/L as CaCOj
3 Carbonate Alkalinity, mg/L a^ CaCOj
4. Hydroxide Alkalinity, mg/L as JaCOj

14.3D The pH is increased because calcium and magne-
sium become less soluble as the pH increases.
Therefore, calcium and magnesium can be removed
from water as insoluble precipitates at high pH
levels.

1 4 3E After the chemical softening process, the scale form-
ing tendencies of water are reduced by bubbling
carbon dioxide (recarbonation) through the water.

14 3F Caustic soda softening might be used in place of
soda ash The decision to use caustic soda rather
than soda ash depends on the quality of the source
water and the delivered costs of various chemicals.

1 . Calculate the phenolphthalein alkalinity in mg/L as

CaCOj.

Phenotphthaiein
Alkalinity.
mg/L as CaC03

A X N X 50.000

inL of sample
(1 2mL)x (0 02 N) x 50.000
100 mL
- 12 mg//.as CaC03

2. Calculate the total alkalinity in mg/L as CaC03.

Total Alkalinity. ^ B x N x 50.000
mg//. as CaCOs mL of sample

(5 6mL)x(0 02N) X (50.000)
100 mL
= 56 mg/L as CaCQ3

3. Refer to Table 14.3 for alkalinity constituents.

From Table 1 4.3 we want the second row because
P = 12 mg/L which is less than V2T[(V2) (56 mg/L)
= 28 mg/L].

Therefore,

a. Bicarbonate Alkalinity = T - 2P

= 56 mg/L -2(12 mg/L)
- 32 mg/L as CaCOg

b. Carbonate Alkalinity = 2P

= 2 (12 mg/L)

= 24 mg/L as CaCOg

c. Hydroxide Alkalinity = 0 mg/L as CaCOj

Answers to questions on page 75.

14.3A The minimum hardness that can be achieved by the
lime-soda ash process is around 30 to 40 mg/L as
CaCOj.

14.3B Benefits that could result from the lime-soda soften-
ing process in addition to softening include:

1. Removnl of iron and manganese,

2. Reduction of solids,

3. Removal and inactivation of bacteria and virus
due to high pH,

4. Control of corrosion and scale formation with
proper stabilization of treated water, and

5. Removal of excess fluoride.

Answers to questions on page 77.

1 4.3C The addition of lime to water increases the hydroxide
concentration, thus increasing the pH.

Answers to questions on page 78.

1 4.3G Calculate the . .ydrated lime (Ca(0H)2) with 90 percent
purity soda ash, and carbon dioxide dose require-
ments in milligrams per liter for the water shown
below.

ERLC

124

Known

Constituents

CO2. mg/L

Total Alkalinity, mg/L

Total Hardness. mg/L

Mg2+.nig/L

Lime Purity. %

Softened Water
After Recarbonetion
Source Water and Filtration

5 mg/L = 0 mg/L

1 50 mg/L as CaC03 = 20 mg/L as CaC03

240 mg/L as CaC03 ^ 50 mg/L as CaC03

= 16 mg/L = 2 mg/L

=74 =88

= 90%

Unknown

Hydrated Lime. mg/L
Soda Ash. mg/L
Carbon D»ox»de. mg/L

1 Calculate the hydrated lime (Ca(0H)2) required in
milligrams per liter.

A = (CO2 mg/L) (74/44)

= (5 mg/L) (74/44)

=^ 8 mg/L
B = (Alkalinity, mg/L) (74/100)

= (150 mg/L) (74/100)

= 111 mg/L
C =0

D - (Mg2^. mg/L) (74/24 3)
-(16 mg/L) (74/24 3)
- 49 mg/L

Hydrated Lime (A + B + C + D) 1 15

(Ca(0H)2) Feed.
mg/L

Hydroxide Alkalinity = 0

Purity of Lime, as a decimal
(8 mg/L + 111 mg/L + 0 + 49 mg/L) 1

0 90

(168 mg/L) (1 15)
090
^ 215 mg/L

Calculate the soda ash required in milligrams per
liter.

Noncarbonate jotal Hardness. Carbonate Hardness.
Hardness. - rng/L as CaCOs ~ mg/L as CaC03
mg/L as CaCOs

240 mg/L - 150 mg/L
= 90 mg/L as CaC03

Soda Ash
(Na2C03) =
Feed. mg/L

, Noncarbonate Hardness., /-nc/mm
<mg/LasCaC03 ) 006/100)

= (90 nr^g/L) (106/100)
= 95 mg/L

Softening 109

3. Caculate the dosage of carbon dioxide required
for recarbonation.

Excess Lime,_ (A + B + C + D) (0 15)
mg/L

= (8mg/t + 111 mg/L + 0 + 49mg/L)(0l5)
= (168 mg/L) (0 15)
= 25 mg/L

Total CO2 ^ (Ca(0H)2 excess. mg/L) (44/74)
Feed, mg/1 + (Mg'^2 residual. mg/L) (44/24 3)

= (25 mg/L) (44/74) + (2 mg/L) (44/24 3)

= 15 mg/L + 4 mg/L

= 19 mg//.

Answers to questions on page 81 .

14.3H In the lime softening process, calcium is precipitated
out as calcium carbonate and magnesium hydroxide.

14.31 Partial lime softening (no magriesium removal) re-
moves hardness caused by calcium ions. This may
be referred io as calcium hardness.

14.3J In split lime treatment, a portion of the water is
treated with excess lime to remove the magnesium at
a high pH. Tne source water (the remaining portion)
is added in the next basin to neutralize (lower the pH)
the excess-lime-treated portion.

14.3K Recarbonation is a process in which carbon dioxide
is bubbled into the water being treated to convert
carbonate ions to bicarbonate ions to stabilize the
->lu*ion against the precipitation of carbonate com-
pounds. The pH may also be lowered by the addition
of acid.

Answers to questions on page 82.

14.3L Lime-soda ash softening is used when lime alone will
not remov-i enough hardness.

14.3M Noncarbonate hardness is removed by the addition
of soda ash in the chemical precipitation softening
process.

Answers to questions on page 82.

14 3N Where the daily requirements tor lime are small, lime
IS usual'y delivered to the wrter treatment plant in
bags.

14.30 Considerahle heat is generat(5d if quicklime acciden-
tally gets wet.

1 4.3P Lime may be applied by dry foeding techniques using
volumetric or gravimetnc feaders.

Answers to questions on page 83.

14.4 A When the alu:n dose i'lcreases for coagulation, the
lime dose rr<ust be increased also.

14.4B Color can be removed from water by coagulation
with alum at 'ow pH values. The high pH values
required during softening tend to "set" the color
which then becomes very difficult to remove.

Answers to questions on page 84.

14.5A A slight excess of lime can cause a scale to form on
the filter sand, distribution mains, and household
plumbing.

ERIC

14.5B Excess caustic and unprecipitated carbonate ions
(pin floe) can be removed from softened water by
recarbonation. Recarbonation is the bubbling of car-
bon dioxide through the water being treated to lower
the pH. Recarbonation can be accomplished, to a
degree, by using source water in the split treatment
mode.

14.5C The marble test is used to deter.nine if a water is
stable. The Langelier Index is also used to determine
the corrosivity of water.

14 5D Suspending a couple of nails on strings in a filter can
indicate if the water is stable. If the nails are rusting,
the water is corrosive. If a scale forms on the nails,
then scale is forming on your filter media and in your
distribution system.

Answers to questions on page 84.

1 4.6A Wooden paddles should be used as cleaning tools on
any slaker in operation. A metal tool will damage the
slaker and could even injure the operator if dropped
by accident. However, a wooden paddle will likely be
broken up with no damage to the equipment or
operator.

14.6B Information on how to safely maintain equipment
may be found in equipment manuals provided by
equipment suppliers and manufacturers.

Answers to questions on •^age 85.

14.7A A disadvantage < recirculating sludge back to the
primary mix area is that an increase in magnesium
could result.

1478 Only trial and error will really determine if sludge
recirculation will serve a useful purpose in your plant.

1 4.8A Records should be kept on the amounts of treatment
plant chemicals ordered and the amounts fed.

Answers to questions on page 86.

14.9A When selecting the target hardness for a water
softening plant, consider the uses of the softened
water and the cost of softening.

14.98 If lime added to water does not reduce the hardness
of a water sufficiently, use the optimum lime do^'e
and run jar tests with varying soda ash doses. Select
the soda ash dose that will produce a water with a
softness of around 80 to 90 mg/L.

Ar .vers to questions on page 90.

14.9C The overfeeding of chemicals is a waste of money
and quality control will suffer.

14.9D What should be the lime feeder setting in pounds per
day to treat a flow of 2 MOD when the optimum Tme
dose IS 160 mg/L'?

Known Unknown

Flow. MGD = 2 MGD Feeder Setting.

Lime Dose. mg/L = 16O mg/L lbs/day

Calculate the lime feeder setting in pounds per day.

^Ibs/day^^"'"^'" (Flow. MGD) (Lime. mg/L) (8.34 lbs/gal)
= (2 MGD) (160 mg/L) (8.34 lbs/gal)
= 2669 lbs/day

. 125

110 Water Treatment

1 4 9E How much soda ash s required m pounds per day to
remove 40 mg//. hardness from a flow of 2 MGD'^

Known Unknown
Flow. MGD = 2 MGD Feeder Setting.

Hardness Removed, mg/t = 40 mg/L lbs/day

1 Calculate the soda ash dose in milligrams per liter.
Soda Ash, mg/l = (1.1) (Hardness Removed, mg/l)

- (1 1)(40 mg/L)
= 44 mg/l

2 Determine the soda ash feeder setting in pounds
per day.

^Ibs/da^^"'"^ ~ (Flow, MGD) (Soda Aoh. mg/L) (8 34 lbs/gal)

- (2 MGD) (44 mg/L) (8 34 IbS/gal)

- 734 lbs/day

14.14A The disposal of spent brine is a problem because
the brine is very corrosive and toxic to many living
things in the environment.

Answers to questions on page 100.

14.15A One valve that fails to open or close during a
regeneration stage could mean a sto^'age tank full
of salty water or no brine.

14 15B Brine pumps and piping must receive constant
attention because a saturated bnne solution Is very
corrosive. An uncontained brine leak will only get
worse,

1 4.1 5C Packing is recommended over mechanical seals on
bnne pumps because sand in mechanical seals will
result in high repair and maintenance costs.

ANSWERS TO QUESTIONS IN LESSON 2

Answers to questions on page 95.

14 10A The three basic types of softeners on the market
are:

1 . An upflow unit,

2 A gravity flow unit, and

3 A pressure downflow unit (tht? most common).

14.108 Dunng the regeneration cycle the softener is taken
out of service. Salt in the form of a concentrated
brine solution is used to r-^generate (recharge) the
ion exchange media. When the brine solution is fed
into the media, the sodium cations are exchanged
for calcium and magnesium cations As the brine
solution travels down through the media, the sodi-
um cations are attached to the media while the
calcium, magnesium and chloride (from the salt)
ions How to waste. After the regeneration has taken
place, the bed is ready to be placed in service again
to remove calcium and magneslun. by ion ex-
change.

Answers to questions on page 97.

14.11 A The source water hardness is the main consider-
ation in determining the length of the service stage
of an ion er'^hange softener.

14.1 IB The purpose of the backwash stage is to expand
and clean the media or resin particles and also to
free any material such as iron and manganese that
might have been removed dunng the softening
stage.

14.1 1C Ion excoange soiteners are regenerated by the use
of a saturated bnne solution

1 4.1 1 D During the rinse stage the softener effluent goes to
waste.

Answers to questions on page 99.

14.12A Hardness should be monitored in the effluent from
an ion exchange softener.

14.13A High chlorine residual levels applied to softening
units could damage the resin and reduce its life
5;pan.

Answers to questions on page 101.

14.16A The maximum expected hardness level in the efflu-
ent from an ion exchange softener should not
exceed one grain hardness per gallon (17.1 mg/L).

14.16B The purpose of the backwash stage is to remove
trapped turbidity particles and other insoluble mate-
nal that is trapped in the resin,

14.16C If the rinse rate starts too soon, the brine solution
could be forced out of the unit before adequate
contact time has elapsed. If the rinse rate is too low,
all the waste matenal might not be removed from
the unit before it goes into the service stage.

14.16D If hardness leakage is excessive immediately fol-
lowing a regeneration stage, shut the unit down and
check the media level. The bed could be disrupted
from excessive backwash or nnse rates. Iron foul-
ing could also cause a channeling condition to
occur and cause the water to short-circuit through
the media without contacting the complete bed
area.

Answers to questions on page 101.

14.17A Ion exchange softeners must be drained and filled
slowly during startup and shutdown to prevent
surging of the media which w'll either wash it out of
the unit or disrupt it, thus making the media uneven
and creating a channeling problem.

14.178 If the pipe work is deteriorating from the brine
solution, PVC pipe should be used as a replace-
ment.

Answers to questions on page 105.

14 18A A source water has a hardness of 150 mg/L as
CaCOg. What is the hardness in grains per gallon?

Known Unknown

Hardness, mg/l = 150 nig/l Hardness, grams/gallon

Calculate the source water hardness in grains per
gallon.

Hardness, ^ (Hardness, mg/L) (1 gpg)
grams/gallon 17.1 mg/L

_ (150 mg/L)(1 gpg)

17.1 mg/L
= 8.8 grams/gallon

ERIC

126

Softening 111

1 4.1 8B An ion exchange softener contains 60 cubic feet of
resin with a hardness removal capacity of 25 kilo-
grains per cubic foot of media. The water being
treated has a hardness of 250 mg/L as CaCOj. How
many gallons of water can be softened before the
softener will require regeneration*?

Kno^n Unknown
Resm Vol. cu ft = 60 cu ft Water Treated, gal

Removal Capacity. = 25.000 gr/cu ft
g^fcu ft

Haidness. mg/l = 250 mg/l

1. Convert the ' ardness from mg/L to grains per
gallon.

Hardness. _ (Hardness. mg/L) (1 gram/gallon)
grams/gallon" 17.1 mg/L

^250 mg/L)(l grarn/gailon)
17.1 mg/L
= 14.6 grams/gallon

2. Calculate the exchange capacity of the softener
in grains.

Exchange

Capacity." (Resin Vol. cu ft) (Removal Capacity, gr/cu ft)
grams . (60 cu ft) (25.000 grams/cu ft)

- 1 .500.000 grams of hardness removal capacity

3 Calculate the volume of water .n gallons that
may be treated before regeneration

Water Treated. ^ Exchange Capacity, grains

9a' Hardness, grains/gallon

_ 1.500.000 grams

14 6 grams/gallon

= 102.700 gallons

Therefore. 102.700 gallons of water with 14.6
grains of hardness per gallon of water can be
treated before the resm becomes exhausted.

Answers to questions on page 106.

14 19A Source water is blended with the effluent from an
ion exchange softener so the consumers will re-
ceive water with an acceptable hardness. Deliver-
ing water with zero hardness is very expensive and
the water is very corrosive.

14 20A Records that should be kept by the operator of an
ion exchange softening plant include:

1 T jtal daily flow through unit.

2. Blend rates.

3 Total daily gallons that have bypassed unit,

4 Gallons of brine used each day,

5. Pounds of salt used each day, and

6. Results of tests performed on source water,
softener effluent and blended water

OBJECTIVE TEST

Chapter 14. SOFTENING

Please write your name and mark the correct answers on
the answer sheet as directed at the end of Chapter 1 . There
may be more than one correct answer to the multiple choice
questions.

TRUE-FALSE

1 Most of the hardness in water is caused by iron.

1 True
2. False

2 Some industrial processes require softer water than is
produced by municipal water treatment plants which
soften water

1. True

2. False

3 The lime-soda ash softening process produces water
with zero hardness.

1. True

2. False

4, Water having a hardness caused by calcium and mag-
nesium bicarbonate ion can usually be softened to an
acceptable level using lime only.

1. True

2. False

5 Recarbonation is a process which causes the precipita-
tion of calcium carbonate

1 True
2. False

6 Water which cannot be softened by lime contains car-
bonate hardness

1 True
2. False

7 Noncarbonate hardness requires the addition of a com-
pound containing carbonate to soften the water.

1. True

2. False

8 The addition of caustic soda to water can remove both
carbonate and noncarbonate hardness.

1 True
2. False

9. Carbonate hardness is caused by the presence of
sulfate and chloride ions.

1. True

112 Water Treatment

10 All three forms of alkalinity can exist at once in a sample 23. The ion exchange softener regeneration and bnne
of water stages are two different stages.

1 True 1 True

2. False 2. False

1 1 Quicklime should never be stored close to combustible
materials.

1. True

2. False

24. During the rinse stage the softener effluent goes to
storage.

1 True
2. False

12 Do not rub your eyes if they become irritated with lime
dust.

1. True

2. False

13 When the alum dose is decreased for coagulation, the
lime dose for softening can be

1. Decreased

2. Increased.

1 4 Recarbonation will actually increase the hardness of the
water slightly.

1. True

2. False

15. Always wear goggles or a face shield when working
with hme that has been or ts in the process of slaking.

1. True

2. False

16 Records will help a good operator to be a better
operator

1. True

2. False

17. An overfeed of lime to some waters will actually in-
crease the hardness.

1 True
2. False

18. Ion exchange water softening is a process in which the
hardnass-causing sodium ions are replaced by calcium
and magnesium ions.

1. True

2. False

25 Ion exchange softening will remove iron and manga-
nese in either the soluble or precipitated form.

1 True
2. False

20 A oaturated brine solution will attack any unprotected
metallic surface it comes in contact with.

1. True

2 False

27 The use of mechanical seals on brine pumps is recom-
mended over packing.

1. True
2 False

28 The brine tanks must be protected from contamination
just like any other water storage facility.

1. True

2. False

29. If iron fouling appears to be a problem with an ion
exchange softener, the duration of the backwash stage
should be decreased.

1. True

2. False

30. If the rinse rate of an ion exchange softener is too low,
all of the waste material might not be removed from the
unit before it goes into the service stage.

1. True

2. False

19 Hard water has an adverse effeci on health.

1, True

2. False

20. Lime softening will remove noncarbonate hardness.

1 True
2. False

21. Changes in the hardness of the source water are
automatically treated by an ion exchange unit.

1. True

2. False

22. At the beginning of the backwash stage, the backwash
water should be applied at a slow steady rate.

1. True

2. False

ERIC

MULTIPLE CHOICE

31. Carbonate hardness is caused by

1. Calcium chlonde.

2. Calcium sulfate.

3. Magnesium bicarbonate.

4. Magnesium chloride.

5. Magnesium sulfate.

32. The two basic methods of softening a municipal water
supply are

1. Ion exchange and chemical precipitation.

2. Ion exchange and lime.

3. Ion exchange and excess lime.

4. Lime and soda ash.

5. Lime-soda ash and caustic soda.

Softening 113

33. Regardless of the method used to soften water, con-
sumers usually receive a softened water with a hard-
ness of around

1. 30 to 40 mg/L.

2. 50 to 60 mg/L.

3. 80 to 90 mg/L.

4. 140 to 150 mg/L

5. 150 to 200 mg/L

41 The chemical feed rates produced by jar tests may not
produce the exact same results in an actual plant
because of differences in

1 Coagulant feed

2 Mixing equipment.

3 Sizes and shapes of jars and basins.

4 Water quality.

5 Water temperature.

34. Removal of noncarbonate hardness by chemical pre-
cipitation requires the addition of a compound contain-
ing

1. Bicarbonate

2. Calcium.

3. Carbonate.

4. Chloride.

5. Sulfate.

35. Items to be cons'dered when deciding whether to use
caustic soda or tne lime-soda ash process to soften
water include

1. Amounts of sludge produced.

2. Costs.

3. Disposal of sludge.

4. Handling and feeding of chemicals.

5. Source water characteristics.

36. Alkalinity exists as

1. Bicarbonate.

2. Carbonate.

3. Hydroxide.

4. pH.

5. Sulfate.

37. How frequently should alkalinity be measured if the
source water for a lime-soda ash process is subject to
change? Every

1. 2 hours.

2. 4 hours.
3- 8 hours.

4. 16 hours.

5. 24 hours.

42. Source water quality changes of concern to the opera-
tor of a lime-soda ash softening plant include changes in

1. Alkalinity

2. Hardness.

3. pH.

4 Temperature.

5 Turbidity.

43. A soft to moderately hard water will have a haraness of
nrig/L as calcium carbonate.

1 . 0 to 45

2. 46 to 90

3. 91 to 130

4. 131 to 170

5. 171 to 250

44. The common stages of operation of an ion exchange
softener include

1. Backwash

2 Brtne.

3 Recarbonation.

4. Rinse.

5. Service

45. Most ion exchange resins on the market will raitce \n

exchange capacity from grains of hardr.ess

removed per cubic foot of resin.

1. 100 to 500

2. 500 to 1000

3. 1000 to 5000

4. 5000 to 20,000

5. 20,0C0 to 30,000

38. Which of the following protective devices could be used
to protect you from lime?

1. Filter mask

2. Gloves

3 Long-sleeved shirt

4. Safety glasses

5. Skin cream

39. How can the pH of softened water be lowered after lime
softening? By the use of

1. Carbon dioxide gas.

2. Caustic soda.

3. Hydrochloric acid.

4. Source water.

5. Sulfuric acid.

46 The backwash duration and flow rate of an ion ex-
change softener will vary depending on the

1. Amount of alkalinity being removed.

2. Amount of hardness being removed.

3. Manufacturer.

4. Temperature of the water.

5. Type of resin used.

47 Which water quality indicators should be monitored in
the influent to an ion exchange softener?

1 Alkalinity

2 HardnpGS

3 Iron and manganese

4. pH

5. Temperature

40. The most common method of sludge disposal is .
disposal.

1. Drying bed

2. Land application

3. Landfill

4. Sewer

5. Sludge recirculation

ERIC

48 Whal type of pipe ma.^nal should be used in a brine
system'^

1. Boron

2. Galvanized

3. Iron

4. PVC

5. Stoel

114 Water Treatment

49 What can the operator do if iron fouling appears to be a
problem on an ion exchange softener'^

1 . Apply a chemical cleaner such as sodium bisulfate

2. Decrease the strength of the brine used in the
regeneration stage

3. Increase backwash flow rates

4. Increase duration of backwash stage

5. Increase duration of service stage

50 Hardness may be expressed as

1 . Grains per gallon.

2. Milligrams per liter

3. Milliliters per liter.

4. Pounds per day.

5. Pounds per million gallons

51 How many gallons of water vMth a hardness of 14 grains
per gallon may be treated by an ion exchange softener
with an exchange capacity of 20,000 kilograms'?

1 OJO M Gal

2 1 07 M Gat
3. 1 24 M Gal

4 1.43 M Gal

5 1.67 fv^ Gal

52. How many hours will an ion exchange softening unit
operate when treating an average flow of 500 GPW
The unit is capable of softening 1,500,000 gallons of
water before requiring regeneration

1 25 hours

2. 30 hours

3. 35 hours

4. 40 hours

5. 50 hours

ERIC

130

CHAPTER 15

TRIHALOMETHANES

Mike McGuire

116 Water Treatment

TABLE OF CONTENTS

Chapter 15. Trihalomethanes

OBJECTIVES

GLOSSARY

15.0 The Trihalomethane (THM) Problem .

15.1 Feasibility Analysis Process

15.2 Problem Definition

15.20 Sampling

15.21 THM Calculations

15.22 Chemistry of THM Formation .

15.3 Control Strategies

15.4 Existing Treatment Processes

Page
. 117
. 118
. 119
. 121
121
121
122
123
124
124

15.5 Treatment Process Research Study Results ^24

15.50 Consider Options

15.51 Remove THMs After They Are Formed ^25

15.52 Remove THM Precursors

15.53 Alternate Disinfectants

15.6 Selection and Implementation of a Cost-Effective Alternative

15.7 Regulatory Update

15.8 Summary and Conclusions

15.9 Arithmetic Assignment

15.10 Additional Reading

SUGGESTED ANSWERS

Chapter 15. TRIHALOMETHANES

Answers to questions on page 121.

15.0A THM precursors are defined as natural organic com-
pounds found in all surface and groundwaters The
THM precursors react with halogens (such as chlo-
nne) to form trihalomethanes (THMs); they must be
present in order for THMs to form.

15.0B Free chlorine is added to drinking water as a disin-
fectant.

15.0C One source of bromide is sea water.

15.0D Trihalomethanes are formed by the reactions of
natural organic compounds with halogens (such as
chlorine).

Answers to questions on page 123.

15.1 A The major steps that a water utility could take to
solve a THM problem include

1. Determine extent of THM problem.

2. Evaluate control strategies,

3. Evaluate existing treatment processes,

4. Examine research studies of treatment proc-
esses,

5. Select most cost-effective option, and

6. Implement selected option.

15 1 B Control strategies that could be evaluated to control
a THM problem include:

1. Change sources of supply, and

2. Treatment options

(a) Remove THMs,

(b) Remove precursors, and

15 2A Important factors that influence the production of
trihalomethanes include the effects of time, tempera-
ture, pH and the types and concentrations of chemi-
cals.

15.28 Those utilities that use lime softening should be
aware that free chlonne in contact with natural or-
ganics at a pH of 10.5 or higher will produce THMs
fastei than if the pH were near 7.0.

Answers to questions on page 124.

15.3A The two types of controlling a THM problem are (1)
change the source of supply or (2) provide some type
of treatment.

15,38 Abandoning the use of free chlorine is a serious
move in view of its superior performance as a
disinfectant.

15.4A Water treatment processes that can be used to
control THMs include:

1. Aeration,

2. Oxidation with potassium permanganate,

3. Coagulation, flocculation and filtration,

4. Softening processes, and

5. Powdered activated carbon applications.

Answers to questions on page 126.

15.5A Aeration is a much more effective process than
oxidation for removing THMs after they have been
formed.

15.58 THM concentrations should be reduced in waters
which have been stored in uncovered reservoirs
because of loss to the atmosphere.

15 5C The adsorption process involves the individual THM
compounds leaving the water and becoming at-
tached to the surface of the carbon or resin.

Answers to ques*'ons on page 126.

15 5D The major treatment processes that have been in-
vestigated to remove THM precursors before they
come in contact with chlorine include:

1. Aeration,

2 Oxidation (including ozone oxidation prior to co-
agulation and clarification).
3. Clarification,
4 Adsorption, and
5. Ion exchange.

15. 5E Moving the addition of free chlorine to a point follow-
ing the clarification process is the key to success
when using clarification to remove THM precursors.

Answers to questions on page 128.

15.5F 8efore an alternate disinfectant is applied to any
system, the source of the water supply, water quality
and treatment effectiveness for bactenological con-
trol must be evaluated.

15.5G Upgraded monitoring (more samples and tests) of
the distribution system before and after a disinfec-
tant change must be provided by a utility.

15. 5H 8efore and after a disinfectant change, the distribu-
tion system monitoring program should include con-
forms, standard plate count, turbidity and nutrients.

Answers to questions on page 129.

15 6A If existing water treatment processes are not capa-
ble of solving a THM problem, the least cost solution
will probably be an alternate disinfectant.

15 68 Apparently the most popular alternate disinfectant is
chloramineo.

Answers to questions on page 130.

15-7A Treatment processes which utilities must evaluate
before applying for and receiving a variance include:

1. Use of chloramines or chlonne dioxide as an
alternative or supplement to chlorine for oxidation
and disinfection,

2. Use of chloramines, chlorine dioxide, or potas-
sium permanganate as an alternative to chlorine
for preoxidatlon,

3. Moving the point of chlorlnation in order to reduce
THM formation,

4. Improvement of existing clarification, and

5. Use of powdered activated carbon (PAC), inter-
mittently as necessary to reduce TTHM or THM
precursors. The dosage of PAC is not to exceed
an annual average of 10 mg/L

147

132 Water Treatment

15 7B If treatment processes are not technically feasible
nor economically reasonable, then utilities must con-
sider-

1. Off-line storage for precursor reduction,

2. Aeration where appropriate.

3 Introduction of clarification where not practiced,

4 Alternative sources of raw water, and

5 Use cf ozone as an alternative or supplement to
chlorine for disinfection or oxidation

OBJECTIVE TEST

ChaptenS. TRIHALOMETHANES

Please write your name and mark the correct answers on
the answer sheet as directed at the end of Chapter 1 . There
n.?y be more than one correct answer to the multiple choice
questtoiib.

TRUE-FALSE

1 . Trihalomethanes are formed in drinking water when free
chlorine comes in contact with naturally occurring or-
ganic compounds.

1. True

2. False

2 The trihalomethane regulations apply to all community
water systems that add a disinfectant to their water
supply.

1. Tru«

2. False

3. The Maximum Contaminant Level (MCL) for total tri-
halomethanes (TTHMs) was established solely on the
basis of health-effects data

1. True

2. False

4. Depending on the type of natural organics present in the
water, the time it takes ior 0.10 mg/L of THMs to form
may range from minutes to days.

1. True

2. False

5. ^^ost THM precursors enter source waters from indus-
trial organic chemicals.

1. True

2. False

6. The concentration of precursors in water is as important
as the types of precursors that are found in v/ater for the
production of THMs.

1. True

2. False

8. Removal of THMs after they are formed using oxidants
has been very successful.

1. True
2 False

9 Aeration is an effective process for removing THMs
from v/ater.

1. True
2 False

10 Aeration is an effective means for removing THM pre-
cursors

1 True
2. False

11. THM precursors vary considerably between locations.

1 True
2, False

12. Removing free chlorine from the chlorine/bromide/pre-
cursor reaction will stop the formation of any significant
amounts of THMs

1. True

2 False

13. A chemical reducing agent is added to THM sample
bottles to stop the chemical reaction between chlorine
and the THM precursors.

1. True
2 False

14 Tnhalomethanes are produced when free chlorine
reacts with naturally occurring bromide and organic
compou.nds.

1 True

2. False

All types of precursors will produce THMs at the same 15. A water utility may apply for a variance from the THM
''3te. regulations.

1. True 1. True

2. False 2. False

er|c

148

Trihalomethanes 133

IViULTiPLE CHOICE

1 6 Examples of organic compounds include

1. Calcium.

2 Carbohydrates.

3. Fats.

4. Trihalomethanes

5. Vitamins

17. Naturally occurring organics get into water when the
water partially dissolves organic materials from

1. Algae.

2. Leaves
3- Rocks.

4. Salts.

5. Soils.

18. The total tnhalomethanes in water are the sum of the
concentrations of

1. Bromodichloromethane.

2. Bromoform

3 Chloroform.

4. Dibromochloromethane.

5. Methane.

1 9. The Maximum Contaminant Level (MCL) for total trihal-
omethanes (TTHMs) IS

1. 0.01 mg/L

2. 0 03 mg/L
3 0.05 mg/L.

4. 0.10 mg/L

5. 0.20 mg/L.

20. Important factors that influence the production of trihal-
omethanes include

1 . Concentration of chemicals.

2. Location of chlorine application.

3. pH.

4. Temperature.

5. Time.

2 1 . Treatment techniques available to control THMs include

1 Drawing water from different levels in a reservoir.

2. Removing THM precursors before chlorine is added

3. Removing THMs after they are formed.

4. Shifting to a different source.

5. Using a disinfectant other than free chlonne.

22 Which of the following treatment processes are effec-
tive in removing THM precursors?

1. Aeration

2. Coagulation, flocculation and filtration

3. Open storage

4. Potassium permanganate

5. Softening processes

23 Which of the following treatment processes are effec-
tive in removing THMs after they have been formed?

1. Adsorption

2. Aeration

3. Coagulation, flocculation and filtration

4. Oxidation

.5. Softening processes

24 Oxidation treatment processes include

1 Chlorine dioxide.

2. Granular activated carbon

3. Ozone.

4 Powdered activated carbon

5 Synthetic resins

25. The most commonly considered alternate disinfectants
to free chlorine are

1. Chloramines

2. Chlorine dioxide.

3. Hydrochloric acid

4 Hypochlonte.

5 Ozone

26. Dechlorination of water containing chloramines can be
accomplished by the use of

1. Activated carbon.

2. Ammonia.

3 Ascorbic acid.

4. Hypochlorite.

5 Sodium thiosulfate.

27. Water quality indicators which should be monitored in
the distribution system before and after a disinfectant
change include

1. Chloride.

2. Coliforms.

3. Nutrients.

4. Standard plate count
5 Turbidity.

28 The results of the quarterly average TTHM measure-
ments for one year are given below. Calculate the
running annual average for the fou^'th quarter.

Quarter 12 3 4

Ave Quarterly TTHM, ^g/L 63 89 121 72

1 43^g/L

2 68^g/L
3. 86^g/L

4 93^g/L

5 95 ^g/L

140

CHAPTER 16

DEMINERALIZATION

ERIC

136 Water Treatment

TABLE OF CONTENTS

Chapter 16 Demineralization
(Removal of Dissolved Minerals by Membrane Processes)

Page

OBJECTIVES .... ^3g

GLOSSARY ^3g

LESSON 1

16.0 Sources of Mineralized Waters

16.1 Demineralizmg Processes -I42

16.2 Reverse Osmosis

16.20 What IS Reverse Osmosis? 142

16.21 Reverse Osmosis Membrane Structure and Composition 145

16.22 Membrane Performance and Properties I45

16.23 Def.nition of Flux 14g

16.24 Mineral Rejection -I4g

16 25 Effects of Feedwater Temperature and pH on Membrane Performance 147

16 25 Recovery

LESSON 2

16.3 Different Types of Reverse Osmosis Plants 153

16.4 Operation 15g

16.40 Pretreatment 15g

16.41 Removal of Turbidity and Suspended Solids 156

16.42 pH and Temperature Control 156

16.43 Other Potential Sealants 156

16.44 Microbiological Organisms 157

16.45 RO Plant Operation 157

16.46 Typical RO Plant Operations Checklist 157

16.47 Membrane Cleaning I61

16.48 Safety 1^2

16.480 Use of Proper Procedures 162

16.481 Chemmals 162

16.482 Hydraulic Safety I62

16.483 Electrical Safety 162

ERIC 151

Demineralization 137

LESSON 3

16.5 Electrodialysis .... 163

16.e Principles of Electrodialysis . . 165

16.60 Anions and Cations in Water 165

16.61 Effects of Direct Current (D.C.) Potential on Ions 165

16.62 Ar.ion and Cation Membranes and Three-Cell Unit 165

16.63 Multi-compartment Unit 165

16.7 Parts of an Electrodialysis Unit 168

16 JO Flow Diagram 168

16 71 Pretreatment 168

16.72 Pumping Equipment and Piping 168

16.73 D.C Power Supply 168

1 6 74 Membrane Stack 1 68

16.75 Chemical Flush System 168

16.8 Routine Operating Procedures ... 168

16.80 Design Specifications for Feedwater 168

16.81 Detailed Operating Procedures 171

16.9 Safety Precautions 171

16.10 Anthmetic Assignment 173

16.11 Additional Reading 173

SUGGESTED ANSWERS

Chapter 16. DEMINHRALIZATION

ANSWERS TO QUESTIONS IN LESSON 1

Answers to questions on page 142.

16.0A Demineralization is the process which removes dis-
solved minerals (sails) from water

16.0B Sea water is more expensive to treat than brackish
water becauses of its much higher TDS concentra-
tion.

Answers to questions on page 142.

16.1 A Methods of removing minerals from water can be
divided into two classes:

1. Those that use a phase change such as freezing
and distillation, and

2. Non-phase change methods such as reverse os-
mosis, eiectrodialysis and ion exchange.

16.1B The common membrane demineralizing processes
are reverse osmosis and electrodialysis.

Answers to questions on page 146.

16.2A The osmotic pressure of a solution is the difference
in water level on both sides of a membrane.

16.2B The modified cellulose acetate membrane is com-
monly used today.

16.2C The water flux is the flow of water in grams per
second through a membrane area of one square
centimeter (or gallons per day per square foot) while
the mineral flux is the flow of mineral.*; in grams per
second through a membrane area of one square
centimeter.

ERIC

16 2D When additional pressure is applied to the side of a
membrane with a concentrated solution, the water
flux (rate of water flow through the membrane) will
increase, but the mineral flux (rate of flow of miner-
als) will remain constant.

16 2E When higher mineral concentrations occur in the
feedwater, the mineral concentrations will increase in
the product water

Answers to questions on page 147.

16 2F Water flux is usually expressed in gallons per day per
square foot (or grams per second per square centi-
meter) of membrane surface.

16.2G The term "flux decline" is used to descnbe the loss of
water flow through the membrane due to compaction
plus fouling.

16,2H Mineral rejection is defined as

Product Concentration

Rejection, % = (1

Feedwater Concentration

)(100%)

Mineral rejection can be determined by measuring
the TDS and using the above equation. Rejections
also may be calculated for individual constituents in
the solution by using their conCv;ntrations.

Answers to questions on page 151.

16 21 An increase m feedwater temperature w'll increase
the water flux.

i6.2J Hydrolysis of a membrane results in a lessening of
mineral rejection capability.

133

Demineralization 175

16.2K Recovery is defined as the percentage feed flow
which Is recovered as product water

Recovery, % =

(Product Flow) (100%)
Feed Flow

16.2L Recovery rate is usually limited by (1) desired prod-
uct water quality and (2) the solubility limits of miner-
als In the brine.

16.2M Concentration pc^rization is the ratio of the mineral
concentration in tho membrane boundary layer to the
mineral concentration in the flow stream.

ANSWERS TO QUESTIONS IN LESSON ^

Answers to questions on page 156.

16.3a The three types of commercially available membrane
systems which have been used in operating plants
are (1) spiral wound, (2) hollow fine fiber, and (3)
tubular.

16.38 The tubular membrane process is used to treat
wastewater with a high suspended solids concentra-
tion.

Answers to questions on page 157.

16.4A To protect the reverse osmosis system and its ac-
cessory equipment, the feedwater should be fiitered.
When the water source is a groundwater or a pre-
viously treated municipal or industrial supply, filtra-
tion may be accomplished by a simple screening
procedure. An untreated surface water will probably
require coagulation, flocculation, sedimentation and
filtration.

1 6.4B Colloidal particulates are removed from feedwater by
chemical treatment and filtration.

16.4C As an acetate membrane hydrolyzes, both the
amount of water and the amount of solute which
permeate the membrane increase and the quality of
the product water deteriorates.

16.4D The scale control method which is used to inhibit
calcium sulfate precipitation is a threshold treatment
with 2 to 5 mg/L of sodium hexametaphosphate
(SHMP).

16.4E A 1 to 2 mg/L chlorine residual is maintained to
control biological fouling.

Answers to questions on page 157.

16.4F Operating pressure on a reverse osmosis unit is
regulated by a control valve on the influent manifold.

16.4G The demineralized water is usually calied PERME-
ATE, the reject BRINE.

16.4H Product or permeate flow is not regulated and varies
as feedwater pressure and temperature change.

Answers to questions on page 162.

1 6.41 Chlorine is added to the feedwater to prevent biologi-
cal fouling.

16.4J The operator must check the differential pressure
across the RO unit to know when to clean the
elements. When the elements become fouled, AP
usually Increases, thus indica ting the need for clean-
ing.

16.4K The reverse osmosis elements should be cleaned
when the operator observes (1) lower product w^,,r
flow rate, (2) lower salt rejection, (3) higher differen-
tial pressure (AP), and (4) higher operating pressure.

Answers to questions on page 162.

16 4L Safety needs for demineralization plants can be
divided into three general groups consisting of
chemicals, electrical and hydraulics.

16.4M Electrical equipment used around reverse osmosis
plants consists of a series of electrically powered
pumps.

ANSWERS TO QUESTIONS IN LESSON 3

Answers to questions on oage 165.

16.5A Typical removals of inorganic salts from brackish
water by ED range from 25 to 40 percent of dissolved
solids per stage of treatment.

16.5B A membrane stack in an electrodialysls unit consists
of several hundred membranes and their separating
spacers assembled between a single set of elec-
trodes. End plates and tie rods complete the assem-
bly.

16.5C The most commonly encountered problem In ED
operation is sealing (or fouling) of the membranes by
both organic and inorganic materials. Alkaline scales
are troublesome in the concentrating compartments
when the diffusion of ions to the surface of the anion
membrane in the diluting cell is insufficient to carry
the current.

Answers to questions on page 165.

16.6A If a D.C. potential is applied across a solution of salt
in v/ater by means of insertion of two electrodes In
the solution, the cations will move towards a negative
electrode, which is known as the "cathode**, and the
anions will move towards the positive electrode,
which Is known as the **anode."

16.6B Only cations (positively charged Ions) can pass
through cation membranes.

16.6C In a multi-compartment ED unit, the compartments
losing salt are labeled "dilute" and those receiving the
transferred salt, "brine."

Answers to questions on page 168.

16.7A Iron, manganese and chlonne residual must be re-
moved from the feedwate*' supply to the electrodiely-
sis unit.

16.7B The rectifier provides the D.C. power to the mem-
brane stack assembly. The input (alternating current,
A.C.) is converted by the rectiiiei to D.C. which is
applied to the electrodes on each side of the mem-
brane stack to remove the ions from the feed stream.

Answers to questions on page 171.

1 6.8A The Ions most often encountered in the feedwater to
an electrodialysls unit include:

Cations Anions

1. Calcium

2. Iron

3. Magnesium

4. Silica

5. Sodium

1. Bicarbonate

2. Chloride

3. Sulfate

176 Water Treatment

16 8B To prevent biological fouling of the cation and anion
membranes, the operator mui't control feed, pH,
biological and bactenological quality.

16.8C Generally the electrodlalysis un.t should NOT be
operated when the feedwater contains any of the
following:

1. Chlorme residual in any concentration,

2. Hydrogen sulfide of any concentration,

3. Calgon or other hexrmetaphospha»es in excess
of 10 mg/L,

4. Manganese iti excess of 0.1 mg/L, and

5. Iron in excess of 0.3 mg/L.

16.8D The recommended daily activities for the operator of
an electrodialysis unit include.

1 . Fill out log sheet,

2. Verify that electrodes are bumping and flowing
properly.

3. Inspect stacks for excess external leakage, and

4. Check the pressure drop across the cartridge
filter and change the cartridges whenever the
pressure drop re' .hes 10 psi.

Answers to questions on page 173.

16.9A Loose connections at the electrode tab connecting
bolf will cause overheating which could result in
serious damage to the membrane stack.

16.9B Expect the D.C. amperage to D/iOP when the feed-
water temperature DROPS.

16.9C Should shorting occur from a metal end plate across
the plastic end block to the electrode, IMMEDIATELY
turn off the rectifier. Try to eliminate the cause of the
shorting by wiping excess moisture off the block.
Also, be sure to completely remove the black carbon
that has formed at the point of shorting.

16.9D If the operation of the '^ntire unit must be stopped
immediately, the M/ j BREAKER should be
switched off.

OBJECTIVE TEST

Chapter 16. DEMINERALIZATION

Please write your name and mark the correct answers on
the cnswer sheet as directed at the end of Chapter 1 . There
may be more than one correct answer to the multiple choice
answers.

TRUE-FALSE

1. Most of the earth's water supplies are fresh water

1. True

2. False

2. All fresh waters contain total dissolved solids (TDS).

1. True

2. False

3. The development of the membrane demineralizmg
processes has significantly increased the cost of demin-
eralizing water.

1. True

2. False

4. Osmosis is the passage of a liquid from a concentrated
to a dilute solution across a semipermeable membrane.

1. True

2. False

5. Semipermeable RO membranes generally must oe
maintained wet at all times.

1. True

2. False

6. When the pressure differential applied across the mem-
brane increases, the salt flux will increase.

1. True

2. False

ERIC

7. Water flux throuah a membrane over time tends to
increase because of membrane erosion.

1. True

2. False

8. Mineral rejection by a reverse osmosis membrane in-
creases as feedwater mineral concentration Increases.

1. True

2. False

9. The value of the water permeation constant is only
constant for a given temperature.

1. True

2. False

10. Minerals are transmitted through the membrane at a
much more rapid rate than water.

1. True

2. False

11. Water to be demineralized always contains impurities
which must be removed by pretreatment.

1. True

2. False

12. The rate of acetate membrane hydrolysis is at its
minimum at about a pH of 4.7, and the rate increases
with both increasing and decreasing pH.

1. True

2. False

13. Reverse osmosis modules provide a large surface area
for the attachment and growth of bacterial slimes and
molds.

1. True

2. False

Demineralization 177

14. The operator of a reverse osmosis plant must properly
maintain and control all flows and recovery' rates to
avoid possible damage to the membranes from scaling.

1. True

2. False

15. The brine flov; valves in a reverse osmosis plant must
never be fully closed.

1. True

2. False

16. To properly operate a reverse osmosis plant, the prod-
uct or permeate flow must be regulated.

1. True

2. False

17. Most RO systems should be operated with the addition
of a scale inhibitor to protect membranes from precipita-
tion of calcium sulfate c*^ other inorganics.

1. True

2. False

18. When starting up a reverse osmosis unit, the feedwater
should always be bypassed until the ph i? properly
adjusted.

1. True

2. False

19. To clean the elements of a reverse osmosis unit, the
elements must be removed from the pressure vessel.

1. True

2. False

20. When working around electrical equipment, shut off and
lock out electrical circuits if you are not a qualified
electrician.

1. True

2. False

21. The removal efficiency of ED units increases with de-
creasing temperature.

1. True

2. False

22. If a D.C. potential is applied across a solution of salt
water, the cations will move towards a negative elec-
trode.

1. True

2. False

23. The negative electrode is known as the anode.

1. True

2. False

24. Electrodialysis requires much higher operating pres-
sures than reverse osmosis.

1. True

2. False

25. The quality of the feedwater to an electrodialysis unit
and Its ionic composition are extremely important.

1. True

2. False

26. A.ways wear rubber gloves when voltage probing the
membrane stack of an electrodialysis unit.

1. True

2. False

27. Always keep the electrodialysis membranes dry when
not In use.

1. True

2. False

28. The gas separator tank on electrodialysis units should
be serviced when the unit is in operation.

1. True

2. False

29. Feeawater containing Calgon or other hexametaphos-
phates will lower membrane stack resistance.

1. True

2. False

30. When an electrodialysis plant is operating on automatic
controls, the plant is controlled by the product water
tank's level switch.

1. True

2. False

MULTIPLE CHOICE

31. The need for demineralizing treatment processes is
increasing due to

1. Agricultural runoff into rivers.

2. Increased demands for water.

3. Increased mineral content of many rivers.

4. Large quantities of mineralized groundwater.

5. Weather modification programs.

32. Demineralizing processes include

1. Distillation.

2. Electrodialysis.

3. Ion exchange.

4. Mineralization.

5. Reverse osmosis.

33. Materials that can be removed by some demineralizing
processes include

1. Bactena.

2. Organic material.

3. pH.

4. Suspended solids.

5. Viruses.

34. The selection of a demineralization process for a par-
ticular application depends on

1. Availability of energy and chemicals.

2. Brine disposal facilities.

3. Mineral concentration in feedwater.

4. Pretreatment required.

5. Product water quality required.

ERLC

178 Water Treatment

35. )Nha\ happens when the osmotic pressure differential
across a membrane decreases?

1. Mineral flux does not change.

2. Mineral flux will decrease.

3. Water flux decreases.

4. Water flux does not change.

5. Water flux increases.

36. Fouling on RO membranes can be caused by

1. Bacteria.

2. Dissolved inorganics.

3. Dissolved organics.

4. Grovirths on membrane surfaces.

5. Suspended solidc;.

37. To insure the longest possible lifetime of a membrane

and to slow hydrolysis is added as a pretreat-

ment step before demlneralization.

1. Ado

2. Alkalinity

3. Caustic

4. Lime

5. Polymer

38. Feedwater should be pretreated to remove materials
and change conditions potentially harmful to the RO
process such as

1. Adjust pH.

2. Adjust temperature.

3. Disinfect to prevent biological growth

4. Remove or prevent scaling or fouling.

5. Remove turbidity /suspended solids.

39. Why is sulfuric acid usually added to the feedwater?

1. To control precipitation of membrane fouling materi-
als.

2. To control precipitation of scale-forming minerals.

3. To improve the alkalinity of the feedwater.

4. To Increase pH.

5. To prevent corrosion.

40. What problems may be caused in the reverse osmosis
process by microbiological organisms?

1. Deterioration of cellulose acetate membrane

2. Increase in conforms in proQuct water

3. Membrane fouling

4. Module plugging

5. Reduction of organic matter

41. Typical operating pressures for brackish water demin-
erallzlng reverse osmosis processes vary from

1. 20 to 40 psi.

2. 70 to 100 osi.

3. 150to350psl.

4. 400 to 500 psi.

5. 1000 to 2000 psi.

42. Which of the following chemicals are used in the oper-
ation of a reverse osmosis unit?

1. Caustic

2. Chlorlns

3. Lime

4. Sodium hexametaphosphate

5. Sulfuric acid

43. The differential pressure (AP) across the RO unit should

not exceed because of possible damage to the

RO modules.

ERIC

1. 20to4C psi

2. 70 to 100 psi

3. 100 to 250 psi

4. 150 to 500 psi

5. 1000 to 2000 psi

44. What rypes of cleaning s'^'utions a e used to remove
biological or organic fouling from an RO membrane?

1. Bactericides

2. Chelating agents

3. Citric acid

4. Detergents

5. Sequestrants

45. Advantages of the electrodialysis process include

1. Efficient removal of most inorganic constituents.

2. Low costs.

3. Low energy requirements.

4. Waste brine contains only salts removed from feed-
water.

5. Well developed technology.

46. The actual percentage removal of mine.als by an ED
unit varies with

1. Flow rate of the water.

2. pH.

3. Stack design.

4. Types and amounts of Ions present.

5. Water temperature.

47. Which of the following ions must be lowered or removed
Ly pretreatment of the feedwater supply to the electro-
dialysis unit?

1. Chlorine residual

2. Hydrogen

3. Hydroxyl

4. Iron

5. Manganese

48. Which of the following tasks should be performed dally
by the operator on an electrodialysis unit?

1. Check the oil level on pumps fitted with automatic
oilers.

2. Fill oul log sheet.

3. Inspect stacks for excess external leakage.

4. Verify that electrodes are bump'ng and flowing prop-
erly.

5. Voltage probe the membrane stacks.

49. Estimate the ability of a reverse osmosis plant to reject
minerals by calculating the mineral rejection as a per-
cent. The teed water contains 1700 mg/L TDS and the
proJjct water is 140 mg/L.

1. 85%

2. 87%

3. 90%

4. 92%

5. 95%

50. Estimate the percent recovery or a reverse osmosis unit
with a 4-2-1 arrangement if the feed flow is 4.5 MGD and
the product *lov/ is 3.9 MGD.

1. 85%

2. 87%

3. 90%

4. 1^5%

5. 95%

19/

CHAPTER 17

HANDLING AND DISPOSAL OF PROCESS WASTES

George Uyeno

180 Water Treatment

TABLE OF CONTENTS

Chapter 17. Handhng and Disposal of Process Wastes

Page

OBJECTIVES

181

GLOSSARY

182

17.0 Need for Handling and Disposing of Process Wastes ^33

17.1 Sources of Treatment Process Wastes ^33

17.2 Process Sludge Volumes ^o>.

io4

17.3 Methods of Handling and Disposing of Process Wastes ^35

17.4 Draining and Cleaning of Tanks ^oc

1 oo

17.5 Backwash Recovery Ponds (Solar Lagoons) ^37

17.6 Sludge Dewatering Processes

17.60 Solar Drying Lagoons

17.61 Sand Drying Beds ^g^

17.62 Belt Filter Presses ^g^

17.63 Centrifuges ^g^

17.64 Filter Presses ^g^

17.65 Vacuum Filters ^g^

17.7 Discharge Into Collection Systems (Sewers) ^gg

17.8 Disposal of Sludge ^g^

17.9 Equipment

^ 200

17.90 Vacuum Trucks 200

17.91 Sludge Pumps

17.10 Plant Drainage Waters 202

17.11 Monitoring and Reporting

17.12 Additional Reading 202

SUGGESTED ANSWERS

Chapter 17. HANDLING AND DISPOSAL OF PROCESS WASTES

Answers to questions on page 183.

17 OA Strict laws are needed regarding the disposal of
process wastes to prevent rivers and streams from
becoming more polluted. These laws are designed to
prevent any waste discharge that could discolor,
pollute or generally be harmful to aquatic or plant life
or the environment.

17. OB If a discharge results from the disposal of process
wastes, such water quality Indicators as pH, turbidity,
TDS, settleable solids and any other harmful materi-
als may require monitonng.

Answers to questions on page 184.

17.1 A Sludge Is removed from sedimentation tanks by
mechanical rakes or scrapers whch periodically
draw out sludge from a hopper or a vacuum-^^'oe
sludge removal device may be used.

17.1B Sludge is removed from upflow solids-contact units
through sludge drawoff lines which must be moni-
tored.

Answers to questions on page 185.

17.2A A source water stabilizing reservoir can reduce the
volume of sludge handled by reducing the turbidity in
the water being treated. Lower turbidities reduce the
amount of alum required and thus the volume of
sludge that settles out.

17.28 If a plant does not have sludge drying beds or
lagoons, the raw or wet sludge can be pumped into a
vacuum tank truck and hauled to a site where the
sludge can be spread out on land to dry or du mped in
a landfill.

Answers to questions on page 185.

17.3A Sludge may be dewatered by the use of belt presses,
centrifuges, filter presses, vacuum filters, solar la-
goons and sand drying beds.

17 38 Sedimeniation tanks should be inspected and re-
paired (if necessary) when the tanks are drained and
cleaned.

Answers to questions on page 187.

17.4A Sludge must be removed manually from tanks with-
out mechanical or vacuum-type sludge collectors.
The tanks must ba drained and then -roerators must
push the sludge to the dram lines with 5> queegees or
the sludge must be pumped out into tanK trucks.

1 7.48 When draining a sedimentation tank, do not drain the
settled water above the sludge to the lagoons or
sludge drying beds. Divert or pump this water to
sedimentation tanks that are in operation, to tne
headworks for reprocessing, or return the water to
the source.

1 7 40 Whenever an operator enters a closed tank (confined
space), be sure that:

1 . No gasoline engines are operated in the tank,

2. Adequate ventilation of clean air is provided at ^11
times.

3- Clean running water is available to wash down
boots and equipment when leaving the tank, and

4. Use the buddy system Someone must be outside
the tank and watching anyone inside the tank.

204 Water Treatment

Answers to questions on page 1 90.

17.5A Time is critical if backwash recovery ponds are used
to handle sludge from sedimentation basins, be-
cause you want to avoid having to backwash the
filters while you are draining a sedimentation tank.

17.5B The suction pipe for the backwash recovery pump
must be floated near the surface of the pond so that
any excess water can be recycled, but the sludge will
not be pumped out of the pond.

17.5C Lime-soda softening sludge can be disposed of
ultimately by

1. Covenng the lagoon with soil,

2. Hauling the dried sludge to a landfill, or

3. Spreading on agncultural soils to adjust the pH for
optimum crop yields.

Answers to questions on page 191.

17 6A The minimum recommended number of solar drying
lagoons is three.

17.6B Sludge drying beds are made with underdralns cov-
ered with gradations of aggregate and sand. The
drains terminate into a sump where recovery pumps
can return the water drained from the sludge back to
the plant to be reprocessed.

17.6C The proper time to remove sludge from the drying
bed is when one foot of sludge has accumulated and
a checkered-shaped piec^ of dry sludge can be
picked up off the sand.

17.6D When operating a front-end loader to remove sludge
from a drying bed. be careful so only the dried sludge
Is picked up with a minimum of disturbance to the
sand and aggregate. The loader oucket capacity
should be limited to one or two cubic yards of sludge
because there may be only about 14 inches of sand
cover over the underdrains.

Answers to questions on page 1 95.

17.6E Sludges may be dewatered using: (1) solar lagoons,
(2) sand drying beds, (3) belt presses, (4) centnfuges,
(5) filter presses, and (6) vacuum filters.

17.6F The principal advantage of using centrifuges to
dewater sludges is that the density of the sludge
cake can be varied from a thickened liquid slurry to a

dry cake. The major limitation of using centrifuges is
high energy consumption.

17.6G A precoat of diatomaceous earth is required to
dewater gelatinous alum sludge.

Answers to questions on page 195.

17 7A The complications of discharging sludge to sewers
include:

1. Fees charged by wastewater treatment plants
could be very high,

2. Increased monitonng requirements and costs,

3. A holding tank may be necessary so the sludge is
released at a uniform rate.

4. Possibility of causing a sewer blockage, and

5. Wastewater treatment plant will have to handle
and dispose of sludge.

^1 7B Brine from ion exchange units is usually discharged
into wastewater collections during the day to take
advantage of high flows for dilution.

Answers to questions on page 200.

17 8A Methods of ultimate sludge disposal include:

1 . Wet sludge can be disposed of on open fields,

2. Wet or dry sludge can be dumped in landfills, and
3 Lime softening sludges may be sold to improve

the pH of agricultural soils

1 7.8B Sludge should be disposed of as close as possible to
the water treatment plant to reduce hauling costs.

Answers to questions on page 202.

17 9A Objects that plug sludge suction hoses get into
water treatment plants by being accidentally
dropped m or thrown in by vandals.

17.9B A diaphragm pump can be used to pump sludge
into a tank on a truck.

17.10A Sources of plant drainage waters include the labo-
ratory, shops and plant drainage water from leaki
and spills.

17,1 1 A Monitonng and reporting requirements for a sludge
disposal program are dictated by the location of
your water treatment plant and the methods used to
ultimately dispose of your process wastes.

OBJECTIVE TEST

Chapter 17. HANDLING AND DISPOSAL OF PROCESS WASTES

Please write your name and mark the correct answers on
the answer sheet as directed at the end of Chapter 1 . There
may be more than one correct answer to the multiple choice
questions.

TRUE-FALSE

1. Many articles and books have been written on sludge
handling and disposal.

1. True

2. False

ERIC

Frequently water treatment plants will use a seciimenta-
tion tank as a backwash recovery area

True
False

Ultimately process wastes must be disposec* of m
manner that will not harm the environment.

1 True

2 False

9':

Process Wastes 205

4 Wet sludge can easily be removed from drying beds by
a front-end loader.

1. True

2. False

5. After draining a sedimentation tank, allow the sludge to
dry on the equipment so the sludge can be easily
removed.

1. True

2. False

6. Sludge that settles out near the entrance to the sedi-
Tientation tank is more dense than the rest of the
sludge.

1 True
2. False

1. The sale of lime sludge as an agricultural liming agent
can help offset sludge handling and disposal costs.

1. True

2 False

8. Brine from ion exchange units is usually discharged into
sewers at night during low flow periods.

1. True

2. False

9 Wet sludge from a sedimentation tank can flow through
pipes by gravity.

1. True

2. False

10. Wet sludge should be dewatered or dried at the plant
before being hauled away.

1. True
2 False

MULTIPLE CHOICE

11. Sources ^f process wastes include

1. Disinfjction.

2. Filter backwash.

3. Grit basins

4. Ion exchange softening.
5 Lime-soda softening.

12. Sludges may be dewaterr J by

1. Centnfuging.

2. Drying.

3. Filter pressing.

4. Flocculating.

5. Lagooning.

13. Sludges and brines may be ultimately disposed of in

1. Lakes.
2 Landfills.

3. Rivers.

4. Streams.

5. Wastewater collection systems.

14 The frequency of draining and cleaning a sedimentation
tank will depend on

1. Backwash rate of rapid sand filters.

2. Detention time in sand filters,

3. Time required to drain and clean tank.

4. Volume of sludge in tank.

5 Volume of treated water in distribution system pipes.

15 How freqently are sedimentation tanks usually drained
and cleaned'?

1. Weekly

2. Monthly

3. Quarterly

4. Semi-annually

5. Annually

16. Treatment processes used in water treatment plants to
reduce the volume of sludge that must be handled and
ultimately disposed of include

1. Conditioning.

2. Dewatering.

3. Digesting.

4. Flocculating.

5. Thickening.

17. Methods of ultimate sludge disposal will depend on

1. Distance to disposal site.

2. Land available.

3. Quality of product water.

4. Sludge moisture content

5. Volume of sludge.

1 8. The frequency of removal of dried sludge will depend on

1. Drying conditions (weather).

2. Number of operators at the plant.

3. Size of drying beds.

4. Time available for operators to do job.

5. Volume of sludge produced.

19. When draining a sedimentation tank, the settled water
above the sludge should be

1. Diverted to the clear well.

2 Diverted to the headworks for reprocessing.

3 Emptied onto the sludge drying beds.

4, Pumped to a sedimentation tank in operation.
5 Recycled to the solar drying ponds.

20. The easiest way to dispose of sludge from a sedimenta-
tion tank IS to

1. Discharge sludge to the sewer.

2 Divert sludge to backwash recovery ponds.

3. Haul sludge to landfill.

4. Pump sludge to drying beds.

5. Spread sludge over land.

21. When releasing wet sludge at one point, the back of the
sludge truck should face downhill so the

1. Spray bars will not become plugged.

2. Tank will empty completely,

3. Tank will empty faster.

4. Truck will not become stuck in the sludge.

5. Water will flow out before the sludge.

^ '•f o

CHAPTER 18

MAINTENANCE

Parker Robinson

208 Water Treatment

TABLE OF CONTENTS

Chapter 18 Maintenance

Page

OBJECTIVES 213

GLOSSARY 214

LESSON 1

18.0 Treatment Plant Maintenance — General Program 218

18.00 Preventive Maintenance Records 218

18.01 Library of Manufacturers' Operation and Parts Manuals 218

18.02 Emergencies 220

18.1 Electrical Equipment 220

1*8.10 Beware of Electricity 220

18.100 Attention 220

18.101 Recognize Your Limitations 221

18.11 Electrical Fundamentals 221

18.110 Introduction 221

18.111 Volts 221

18.1 12 Direct Current (D.C.) 223

18.113 Alternating Current (A.C.) 223

18.114 Amps 224

18.115 Watts 224

18.116 Power Requirements 225

18.1 17 Conductors and Insulators 225

18.12 Tools, Meters and Testers 225

18.120 Voltage Testing 225

18.121 Ammeter 227

18.122 Megger 229

18.123 Ohm Meters 230

18.13 Switch Gear 230

18.130 Equipment Protective Devices 230

18.131 Fuses 230

18.132 Circuit Breakers 230

18.133 Overload Relays 231

18.134 Motor Starters 231

ERLC

228

Maintenance 209

18 14 Electric Motors 234

18 140 Classifications 234

18.141 Troubleshooting 236

18.142 Recordkeeping 236

18.15 Auxiliary Electrical Power 244

18.150 Safety First 244

18.151 Stanc Power Generation 244

18.152 Emergency Lighting 245

18.153 Batteries 245

18.16 High Voltage 246

18.160 Transmission 246

18.161 Switch Gear 246

1 8. 1 62 Power Distribution Transformers 247

18.17 Electrical Safety Check List 247

18.18 Additional Reading 247

LESSON 2

18.2 Mechanical Equipment 249

18.20 Repair Shop 249

18.21 Pumps 249

18.210 Centrifugal Pumps 249

1 8.21 1 Let's Build a Pump 249

18.212 Horizontal Centrifugal Pumps 257

18.213 Vertical Centrifugal Pumps 257

18.214 Reciprocating or Piston Pumps 257

18.215 Progressive Cavity (Screw-Flow) Pumps 257

18.216 Chemical Metering Pumps 258

18.22 Lubrication 262

1 8.220 Purpose of Lubrication 262

1 8.221 Properties of Lubricants 262

18.222 Lubrication Schedule 262

18.223 Precautions 263

18.224 Pump Lubrication 263

18.225 Equipment Lubrication 263

LESSON 3

18.23 Pump Maintenance 265

18.230 Section Format 285

18 231 Preventive Maintenance 265

1. Pumps, General 265

2. Reciprocating Pumps, General 272

ER?C 229

210 Water Treatment

3. Propeller Pumps, General 273

4. Progressive Cavity Pumps, Genera! 273

5 Pump Controls 273

5. Electric Motors 274

7 Belt Drives . . 274

8 Cham Drives 277

9. Variable Speed Belt Drives 278

10 Couplings 27s

11. Shear Pins 280

18.24 Pump Operation 282

18.240 Starting a New Pump . 282

18.241 Pump Shutdown 282

18 242 Pump-Driving Equipment 282

18.243 Electrical Controls 282

18.244 Operating Troubles 283

18.245 Starting and Stopping Pumps 284

18.2450 Centrifugal Pumps 284

18.2451 Positive Displacement Pumps 286

LESSON 4

18 25 Compressors 287

18.26 Valves 289

18.260 Uses of Valves 289

18.261 Gate Valves 289

18.262 Maintenance of Gate Valves 291

12. Gate Valves 29i

18 263 Globe Valves 292

18.264 Eccentric Valves 292

18.265 Butterfly Valves 292

18.266 Check Valves 296

18.267 Maintenance of Check Valves 305

13. Check Valves 3Q5

18.268 Automatic Valves 3Q5

LESSON 5

18.3 Internal Combustion Engines ^oj

18.30 Gasoline Engines 307

18.300 Need to Maintain Gasoline Engines ^07

18.301 Maintenance ^Qj

18.302 Starting Problems 3O7

ERLC

230

Maintenance 211

18.303 Running Problems 307

18.304 How to Start a Gasoline Engine ... 308

18.3040 Smali Engines 308

18.3041 Large Engines 308

18.31 Diesel Engines 309

18 310 How Diesel Engines Work 309

18.311 Operation 309

18 312 Fuel System 311

18 313 Water-cooled Diesel Engines . 311

18.314 Air-cooled Diesel Engines 311

1 8.31 5 How to Start Diesel Engines 311

18 316 Maintenance and Troubleshooting 311

18 32 Cooling Systems 313

18 33 Fuel Storage 315

18.330 Code Requirements 315

18.331 Diesel 315

18.332 Gasoline 315

18.333 Liquified Petroleum Gas (LPG) 316

18 334 Natural Gas 316

18.34 Standby Engines 316

18.4 Chemical Storage and Feeders 316

18.40 Chemical Storage 316

18.41 Drainage from Chemical Storage and Feeders 317

18.42 Use of Feeder Manufacturer's Manual 317

18.43 Solid Feeders 317

18.44 Liquid Feeders 317

18.^0 Gas Feeders 317

18.46 Calibration of Chemical Feeders 317

1 8.460 Large-Volume Metering Pumps 317

18 461 Small-Volume Metering Pumps 317

1 8 462 Dry-Chemical Systems 317

18.47 Chlorinators 320

18.5 Tanks and Reservoirs 321

18.50 Scheduling Inspections 321

18.51 Steel Tanks ....321

18.52 Cathodic Protection 321

18.53 Concrete Tanks 321

18.6 Building Maintenance 321

ERIC 231

112 Water Treatment

18.7 Arithmetic Assignment

18.8 Additional Reading

18.9 Acknowledgments .
Suggested Answers
Objective Test

322
322
322
323
327

er|c

Maintenance 213

OBJECTIVES

Chapter 18. MAINTENANCE

Following completion of Chapter 18, you should be able
to:

1 Develop a maintenance program for your plant, includ-
ing equipment, buildings, grounds, channels, and tanks;

2. Start a maintenance recordkeeping system that wiil
provide you with information to protect equipment war-
ranties, to prepare budgets, and to satisfy regulatory
agencies;

3. Schedule maintenance of equipment at proper time
intervals;

4. Perform maintenance as directed by manufacturers;

5. Recognize symptoms that indicate equipment is not
performing properly, identify the source of the problem,
and take corrective action;

6. Recognize the serious consequences that could occur
when inexperienced, unqualified or unauthorized per-
sons attempt to troubleshoot or repair electnca! panels,
controls, circuits, wiring or equipment;

7. Communicate with electricians by indicating possible
causes of problems in electrical panels, controls, cir-
cuits, wiring, and motors;

8 Properly select and use the following pieces of equip-
ment (if qualified and authorized):

a. Voltage tester.

b. Ammeter,

c. Megger, and

d. Ohm meter;

9. Safely operate and maintain auxiliary electrical equip-
ment, including during standby and emergency situa-
tions;

10. Descnbe how a pump is put together;

11. Discuss the application or use of different types of
pumps;

12. Star* and stop pumps;

13. Maintain the various types of pumps;

14. Operate and maintain a compressor;

15. Develop and conduct an equipment lubrication pro-
gram; and

16. Start up, operate, maintain and shut down gasoline
engines, diesel engines, heating, ventilating and air
conditioning systems.

NOTE: Special maintenance information is given in the pre-
vious chapters on treatment processes where appro-
pnate.

^ Jo

214 Water Treatment

GLOSSARY

Chapter 18. MAINTENANCE

AIR GAP

A.i open vertical drop, or vertical empty space, that sepa-
rates a drinking (potable) water supply to be protected from
another system in a water treatment plant or other location.
This open gap prevents the contamination of drinking water
by backsiphonage or backflow because there is no way raw
water or any other water can reach the drinking water.

DRINKING
WATER

AIR GAP

ALTERNATING CURRENT (A.C.]

An electric current that reverses its direction (positive/negative values) at regular intervals.
AMPERAGE (AM-purr-age) AMPERAGE

The strength of an electric current measured in amperes. The amount of electric current flow, similar to the flow of water in gal-
lons per minute. ^

AMPERE (AM-pesr) AMPERE

The unit usee to measure current strength The current produced by an electromotive force of one volt acting through a resis-
tance of one ohm. ^ ^

AMPLITUDE AMPLITUDE
The maximum strength of an alternating curren. dunng its cycle, as distinguished from the mean or effective strength.

AXIAL TO -MPELLER AXIAL TO IMPELLER

The direc'fjn in which materia! being pumped flows around the impeller or parallel to the impeller shaft.

AXIS OF IMPELLER AXIS OF IMPELLER

An imaginary line running along the center of a shaft (such as an impeller shaft).

BRINELLING (bruh-NEL-ing) BRINELLING
Tiny indentations (dents) high on the shoulder of the bearing race or bearing. A type of beanng failure.

CATHODIC PROTECTION (ca-THOD-ick) CATHODIC PROTECTION

An electrical system ior prevention of rust, corrosion, and pitting of metal surfaces which are in contact with water or soil. A
low-voltage current is made to flow through a liquid (water) or a soil in contact with the metal in such a manner that the external
electromotive force renders the metal structure cathodlc. This concentrates corrosion on auxiliary anodic parts which are delib-
erately allowed to corrode instead of letting the structure corrode.

CAV; ."ATION (CAV-uh-TAY-shun)

The formation and collapse of a gas pocket or bubble on the blade of an impeller or the gate of a valve. The collapse of this qas
pocket or bubble drives water into the impeller or gate with a terrific force that can cause pitting on the impeller or gate surface
Cavitation is accompanied by loud noises that sound like someone is pounding on the impeller or gate with a hammer.

C'RCU'T CIRCUIT

The complete path of an electric current, including the generating apparatus or other source, or, a specific segment or section
of the complete pith. "

■Jit

CAVITATION

Maintenance 215

CIRCUIT BREAKER CIRCUIT BREAKER

A safety device in an elBCtrica! circuit that automatically shuts off the circuit when it becomes overloaded. The device can be
manually reset.

CONDUCTOR CONDUCTOR
A substance, body, device or wire that readily conducts or carries electrical current.

COULOMB (COO-lahm) COULOMB

A measurement of the amount of electncal charge conveyed by an electnc current of one ampere in one second. One coulomb
equals about 6.25 x 10^^ electrons (6,250,000,000,000,000,000 electrons).

CROSS-CONNECTION CROSS-CONNECTION

A connection between a drinking (potable) water system and an unr^pprovea water supply. For example, if you have a pump
moving non-potable water and hook into the drinking water system to supply water for the pump seal, a cross-connection or
mixing between the two water systems can occur. This mixing may lead to contamination of the drinking water.

CURRENT CURRENT

A movement or flow of electricity. Water flowing in a pipe is measured in gallons per second past a certain point, not by the
number of water molecules going past a point. Electric current is measured by the number of coulombs per second flowing past
a certain point in a conductor. A coulomb is equal to about 6.25 x 10^® electrons (6,250,000,000,000,000,000 electrons). A flow
of one coulomb per second is called one ampere, the unit of the rate of flow of current.

CYCLE CYCLE
A complete alternat;on of voltage and/or current in an alternating current (A.C.) circuit.

DATEOMETER (day-TOM-uh-ter) DATEOMETER

A small calendar disc attached to motors and equipment to indicate the year in which the last maintenance service was per-
formed.

DIRECT CURRENT (D.C.) DIRECT CURRENT (D.C.)

Electrical current flowing in one direction only a"d essentially free from pulsation.

ELECTROLYTE (ee-LECK-tro-LIGHT) ELECTRo^ HE

A substance which dissociates (separates) into two or more ions when it is dissolved in v/ater.

ELECTROMOTIVE FORCE (E.M.F.) ELECTROMOTIVE FORCE (E.M.F.)

The electrical pressure available to cause a i\o/j of current (amperage) when an electrical circuit is closed. See VOLTAGE.

ELECTRON ELECTRON
An extremely small, negatively-charged particle, the part of an atom that determines its chemical properties,

END BELLS END BELLS

Devices used to hold the rotor and stator of a motor in position.

FUSE FUSE

A protective device having a strip or wire of fus.b(ci metal which, when placed in a circuit, will melt and break the electrical circuit
if heated too much. High temperatures v/iH develop in ..he fuse when a current flows through the fuse in excess of that which the
current will carry safely.

GROUND GROUND

An expression representing an electrical connection to earth or a large conductor which is at the earth's potential or neutral
voltage.

HERTZ (HUR^S) HERTZ

The number of complete electromagnetic cycles or waves in one second of an electncal or electronic circuit. Also called the fre-
quency of the current. Abbreviated Hz.

HYGROSCOPIC (HI-grow-SKOP-ick) HYGROSCOPIC
Absorbing or attracting moisture from the air.

JOGGING JOGGING
The frequent etarting and stopping of an electric motor.

23-.;

216 Water Treatment

LEAD (LEE-d) LEAD
A wire 0. conductor that can carry electricity.

MANDREL (MAN-drill) MANDREL
A special tool used to push beanngs in or to pull sleeves out.

MEG I^EG

A procedure used for checking the insulation resistance on motors, feeders, buss bar systems, grounds, and branch circuit wir-
ing. Also see MEGGER.

MEGGER (from megohm) MEGGER

An instrument used for checking the insulation resistance on motors, feeders, buss bar systems, ground, and branch circuit
wiring. Also see MEG

MEGOHM MEGOHM
Meg means one million, so 5 megohms means 5 million ohms. A megger reads in millions of ohms.

MULTI-STAGE PUMP MULTI-STAGE PUMP

A pump that has more than one impeller. A single-stage pump has one Impeller.

OHM OHM
The unit of electrical resjstance The resistance of a conductor in which one volt produces a current of one ampere.

POLE SHADER POLE SHADER

A copper bar circling the laminated Iron core inside the coil of a magnetic starter.

POWER FACTOR pOWER FACTOR

The ratio of the true power passing through an electric circuit to the prodj'-t of the voltage and amperage in the circuit. This is a
measure of the lag or load of the current with respect to the voltage. In altemating current the voltage and ampere' are not
always in phase; therefore, the true power may be slightly less than that determined by the direct product.

PRUSSIAN BLUE PRUSSIAN BLUE

A blue paste or liquio (often on a paper like carton paper) used to show a contact area. Used to determine if gate valve seats fit
properly.

RADIAL TO IMPELLER RADIAL TO IMPELLER

Perpendicular to the impeller shaft. Material being pumped flows at rinht angle to the impeller.

RESISTANCE RESISTANCE

That property of a conductor or wire that opposes the passage of a current, thus causing electrical energy to be transformed
into heat.

ROTOR ROTOR
The rotating part of a machine. The rotor is surrounded by the stationary (non-moving) parts (stator) of the machine.

SEIZE UP SEIZE UP

Seize up occurs when an engine overheats and a part expands to 'he point where the engine will not run. Also called "freezing."

SHEAVE (SHE-v) SHEAVE
V-belt drive pulley which is commonly made of cast iron or steel.

SHIM SHIM

Thin metal sheets wnich are inserted between two surfaces to align or space the surfaces correctly. Shims can be used any-
where a spacer is needed. Usually shims are 0.001 to 0.020 inches tnick.

SINGLE-STAGE PUMP SINGLE-STAGE PUMP

A pump that has only one impeller. A multi-stage pump has more than one impeller.

STATOR STATOR
That portion of a machine which contains the stationary (non-moving) parts that surround the moving parts (rotor).

Maintenance 217

STETHOSCOPE STETHOSCOPE
An instrument used to magnify sounds and convey them to the ear.

VOLTAGE VOLTAGE

The electrical pressure available to cause a flow of current (amperage) when an electrical circuit is closed. See ELECTROMO-
TIVE FORCE (E.M.F.).

WATER HAMMER WATER HAMMER

The sound like someone hammering on a pipe that occurs when a valve is opened or closed very rapidly When a valve position
IS changed quickly, the water pressure in a pipe will increase and decrease back and forth very quickly. This rise and fall in
pressure can do serious damage to the system.

237

218 Water Treatment

CHAPTER 18. MAINTENANCE

(Lesson 1 of 5 Lessons)

1 8.0 TREATMcNT PLANT MAINTENANCE — GENERAL
PROGRAM

A water treatment plant operator has many duties. Most of
them have to do with the efficient operation of the plan. An
operator has the responsibility to produce a water that will
meet all the requ -ements established for the plant. By doing
this, the operator develops a good working relationship with
the regulatory agencies, water users, and plant neighbors.

Another duty an operator has is that of PLANT MAINTE-
NANCE. A good maintenance program is a must in order to
maintain successful operation of the plant. A successful
maintenance program will cover everything from mechanical
equipment to the care of the plant grounds, buildings, and
structures,

Mechanical maintenance is of prime importance as the
equipment must be kept in good operating ccr.Jitlon in order
for the plant to maintain peak performance. Manufacturers
provide information on the mechanical maintenance of their
equipment. You should thoroughly read their literature on
your plant equipment and UNDERSTAND the procedures.
Contact the mar ifacturer or the local representative if you
have any questions Follow the instructions very carefully
when performing maintenance on equipment. You also must
recognize tasks that may be beyond your capabilities or
repair facilities, and you should request assistance when
needed.

For a successful maintenance program, your supervisors
must understand the need for and benefits from equipment
that operates continuously as intended Disabled or improp-
erly working equipment is a threat to the quality of the plant
output, and repair costs for poorly maintained equipment
usually exceed the cost of maintenance.

18.00 Preventive Maintenance Record

Preventive programs help operating personnel keep
equipment in satisfactory operating condition and aid in
detecting and correcting malfunctions before they develop
into major problems.

A frequent occurrence in a preventive maintenance pro-
gram is the failure of the operator to record the work after it
is completed. When this happens the operator must rely on
memory to know when to perform each preventive mainte-
nance function. As days pass into weeks and months, the
preventive maintenance program Is lost in the turmoil of
everyday operation.

The only way an operator can keep track of a preventive
maintenance program is by GOOD RECORDKEEPING.
Wh.' ever record system is used, it should be kept up to date
on aily basis and not left to memory for some other time.
Equipment service record cards (Figure 1 8.1 ) are easy to set
up and require little time to keep up to date.

ERIC

An EQUIPMENT SERVICE CARD (master card) should be
filled out for each piece of equipment in the plant. Each card
should have the equipment name on it, such as Raw Water
Intake Pump No. 1

1 List each required maintenance service with an item
number,

2 List maintenance services in order of frequency of per-
formance. For instance, show daily service as Items 1,2,
and 3 on the card; weekly items as 4 and 5; mof ithly items
as 6, 7, 8, and 9; and so on.

Describe each type of service under work to be done.

Make sure all necessary inspections and services are
shown. For reference data, list paragraph or section num-
bers as shown in the pump maintenance section of this
lesson (Section 18.23, p. 265) Also list frequency of service
as shown in the time schedule columns of tl j same section.
Under time, enter day or month service is due. Service card
information may be changed to fit the needs of your plant or
particular equipmen' as recommended by the equipment
manufacturer. Be oure the information on the cards is
complete and correct.

The SERVICE RECORD CARD should have the date and
work done, listed by item number and signed by the operator
who p<^rformed the service. Some operators prefer to keep
both cards clipped together, -while otners place the service
record card near the equipment.

When the service record is filled, it should be filed for
future reference and a new card attached to the master card.
The EQUIPMENT SERVICE CARDXeWs what should be done
and when, while the SERVICE RECORD CARDis a record of
what you did and when you did it.

1 8.01 Library of Manufacturers* Operation and Parts
Manuals

A plant library can contain helpful information to assist in
plant operation. Material m the library should be cataloged
and filed for easy use. Items in the library should include:

238

Maintenance 219

EQUIPMENT SERVICE CARD

EQUIPMENT. #1 Raw Water Intake Pump

Item No.

Work to be Done

Reference*^

Time

Check water seal and packing qiand

Par. 1

Daily

Listen for u jsuai noises

Par. 6

Daily

Operate pump alternately

Par. 1

Wppklv

1 VI ^1 ivjcx y

Inspect pump assembly

Par. 1

Weekly

Wednesday

Inspect and lube bearings

Par. 1

Quarterly

1-4-7-10^

Check operating temperature of bearings

Par. 1

Quarterly

1-4-7-10^

Check alignment of pump and motor

Par. 1

Semi-Ann.

4 &10

Inspect and service pumps

Par. 1

Semi-Ann.

4 & 10

Dram pump before shutdown

Par. 1

SERVICE RECORD CARD

EQUIPMENT: #1 Raw Water Intake Pump

Date

Work Done
(Item No.)

Signed

Date

Work Done
(Item No.)

Signed

1-5-84

1-2-3

J.B.

1-6-84

1-2

J.B.

1-7-84

1-2-4-5-6

R.W.

a Par. 1 refers to Paragraph 1 in Section 18.23 of this manual Par. 6 is also in Section 18.23.

b 1-4-7-10 represent the months of the year when the equipment should be serviced — 1 -January, 4-April, 7-July. and 10-October.

^ Fig. 18. 1 Equipment service card and service record card

ERIC

'^3 J

220 Water Treatment

1. Plant operation and maintenance instruction manuals,

2. Plant plans and specifications,

3. Manufacturers' instructions,

4. Reference books on water treatment,

5. Professional journals and publications,

6. First-aid book,

7. Reports from other plants, and

8. A dictionary.

18.02 Emergencies

If your plant has not developed procedures for handling
potential emergencies, do it NOW. Emergency procedures
must be established for operators to follow when emergen-
cies are caused by the release of chlorine, hazardous or
toxic chemicals into the raw water supply, power outages or
broken transmission lines or distribution mains. These pro-
cedures should include a list of emergency phone numbers
located near a telephone that is unlikely to be affected by the
emergency.

1. Police

2. Fire

3. Hospital and/or Physician

4. Responsible Plant Officials

5. Local Emergency Disaster Office

6. CHEMTREC (800) 424-9300

7. Emergency Team (if your plant has one)

The CHEMTREC toll-free number may be called at any
time. Personnel at this number will give information on how
to handle emergencies created by hazardous materials and
will notify appropriate emergency personnel.

An emergency team for your plant may be trained and
assigned the task of responding to SPECIFIC EMERGEN-
CIES such as chlorine leaks. This emergency team must
meet the following strict specifications at all times.

1 . Team personnel must be physically and mentally quali-
fied.

2. Proper equipment must be available at all times, includ-
ing:

a. Protective equipment, including self-contained breath-
ing apparatus,

b. Repair kits, and

c. Repair tools.

3. Proper training must take place on a regular basis and
include instruction about:

a. Properties and detection of hazardous chemicals,

b. Safe procedures for handling and storage of chemi-
cals,

c. Types of containers, safe procedures for shipping
containers, and container safety de*-ices, and

d. Installation of repair devices.

4. Team members must be exposed regularly to simulated
field emergencies or practice dnils. Team response must

ERIC

be carefully evaluated and any errors or weaknesses
corrected

5 Emergency team performance must be reviewed annually
on a specified date. Review must include:

a. Training program,

b. Response to actual emergencies, and

c. Team physical and mental examinations.

WARNING. One person should never be permitted to at-
tempt an emergency repair alone. Always wait
for trained assistance. Valuable time could be
lost rescuing a foolish Individual rather than
repairing or correcting a serious emergency.

For additional information on emergencies, see Chapter 7,
Disinfection, Section 7.52, "Chlorine Leaks," Chapter 10,
Plant Operation, Section 10.9, "Emergency Conditions and
Procedures," and Chapter 23, Administration, Section 23 3,
"Contingency Planning for Emergencies." Chapter 23 con-
tains information on what to do if a toxic substance gets into
your water supply.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 323.

18.0A Why should you plan a gov-d maintenance program
for your treatment plant?

18.0B What general items would you include in your mainte-
nance program?

18.0C Why should you have a good recordkeeping system
for your maintenance program*?

18.0D What is the difference between an EQUIPMENT
SERVICE CARD and SERVICE RECORD CARD?

18 OE Prepare a lis\ emergency phone numbers for your
treatment plant.

18 OF What Items should be included in the training pro-
gram for an emergency team?

18.1 ELECTRICAL EQUIPMENT

18.10 Beware of Electricity

18,100 Attention

A. DO NOT ATTEMPT TO INSTALL, TROUBLESHOOT,
MAINTAIN, REPAIR OR REPLACE ELECTRICAL EQUIP-

2-io

Maintenance 221

MENT, PANELS, CONTROLS, WIRING OR CIRCUITS
UNLESS YOU

1 KNOW WHAT YOU ARE DOING,

2. ARE QUALIFIED, AND

3. ARE AUTHORIZED.

Sect.on 1811, Electrical Fundamentals, is presented to
provide you with an understanding and awareness of
electricity. THE PURPOSE OF THE SECTION IS TO
HELP YOU PROVIDE ELECTRICIANS WITH THE INFOR-
MATION THEY WILL NEED WHEN YOU CONTACT
THEM AND REQUEST THEIR ASSISTANCE. YOU MUST
BE EXTREMELY FAMILIAR WITH ELECTRICITY BE-
FORE ATTEMPTING ANY MAJOR REPAIRS.

B. Due to the wide variety of equipment and manufacturers,
in the water treatment field, detailed procedures for the
maintenance of some types of equipment were very
difficult to include in this chapter. Also manufacturers are
continually improving their products and some details
would soon be out of date FOR DETAILS CONCERNING
THE OPERATION, MAINTENANCE AND REPAIR OF A
PARTICULAR PIECE OF EQUIPMENT REFER TO THE
O & INSTRUCTIONS MANUAL OR CONTACT THE
MANUFACTURER.

C Effective equipment maintenance is the key to successful
system performance. The better your maintenance, the
better your facilities will perform. Abuse your equipment
and facilities and they will abuse you Everyone must
realize that if the equipment can't work, no one can work

18. 101 Recognize Your Limitations

In the water departments of all cities, there is a need for
maintenance operators to know something about electricity.
Duties could range from repairing a tail light on a trr'ler or
vehicle to repairing complex pump controls and motors
VERY FEW MAINTENANCE OPERATORS DO THE ACTU-
AL ELECTRICAL REPAIRS OR TROUBLESHOOTING BE-
CAUSE THIS IS A HIGHLY SPECIALIZED FIELD AND
UNQUALIFIED PEOPLE CAN SERIOUSLY INJURE THEM-
SELVES AND DAMAGE COSTLY EQUIPMENT. For these
reasons, you must be familiar with electricity, KNOW THE
HAZARDS, and RECOGNIZE YOUR OWN LIMITATIONS
when you must work with electrical equipment.

Most municipalities employ electncians or contract with a
commercial electrical company that they call when major
problems occur. However, the maintenance operator should
be able to EXPLAIN HOW THE EQUIPMENT IS SUPPOSED
TO WORK AND WHAT IT IS DOING OR IS NOT DOING
WHEN IT FAILS. Aftfir studying this section, you should be
able to tell an electrician what appears to be the problem
with electrical panels, controls, circuits and equipment.

The need for safety should be apparent. If proper safe
procedures are not followed in operating and maintaining
the various electrical equipment used in water treatment
facilities, accidents can happen that cause injuries, perma-
nent disability, or loss of life. Some of the serious accidents
that have happened and could have been avoided occurred
when machinery was not shut off, locked out, and tagged
properly (Figure 18.2) Possible accidents include:

1. Maintenance operator could be cleaning pump and have
It start, thus losing an arm, hand, or finger,

2 Electrical motors or controls not properly grounded could
lead to possible severe shock, paralysis, or death, and

3 Improper circuits such as a wrong connection, safety
devices jumped, wrong fuses, or improper wiring can
cause fires or injuries due to incorrect operation of
machinery

Another consideration for having a basic working knowl-
edge of electricity is to prevent financial losses resulting
from motors burning out and from damage to equipment,
machinery and control circuits. Additional costs result when
damages have to be repaired, including payments for out-
side labor

. WARNING I

PiNlC^^UTfMHAT VOU C?^MT ^hi^Wl fi^^^UT

QUESTIONS

Wnte your answers in a notebook and then cr-^pare your
answers v^ith those on page 323

18.10A Why must unqualified or inexperienced people be
extremely careful when attempting to Iroubleshoot
or repair electrical equipment*?

1 8. 1 0B What could happen when machinery is not shut off,
locked out, and tagged properly?

18.11 Electrical Fundamentals

18.110 introduction

This section contains a basic Introduction to electrical
terms and information plus directions on how to trouble-
shoot problems with electrical equipment.

Most electrical equipment used in water treatment plants
IS labeled with name plate information indicating the proper
voltage and allowable current In amps.

18.111 Volts

Voltage (E) Is also known as Electromotive Force (E.M.F.),
and IS the electrical pressure available to couse a flow of

ERIC

24.1

222 Water Treatment

DANGEK

MAN
WORKING
ON LINE

DO NOT CLOSE THIS
SWITCH WHILE THIS
TAG IS DSSPLAYED

SIGNATURE

This IS the ONLY person authorized to remove this tag

Note: Tag also should include: TIME OFF

DATE

Fig. 16.2 Typical warning tag

(Source industrial Indemnity/industrial Underwnters/lnsurance Cos )

ER?C 242

Maintenance 223

current (amperage) when an electrical circuit is closed.^ This
pressure can be compared with the pressure or force that
causes water to flow in a pipe Some pressure in a water
pipe IS required to make the water move The same is true of
electricity. A force is necessary to push electricity or electnc
current through a wire This force is called voltage. There
are two types of current Direct Current (D C ) and Alternat-
ing Current (A.C.).

18. 1 12 Direct Current (D,C,)

Direct Current (D.C ) flows in one direction only and is
essentially free from pulsation. Direct current is seldom used
in water treatment plants except m electronic equipment,
some control components of pump dnves and stand-by
lighting Direct current is used exclusively i automotive
equipment, certain types of welding equipment, and a vari-
ety of portable equipment. Direct current is found in various
voltages such as 6 volts, 1 2 volts, 24 volts, 48 volts, and 1 1 0
volts All batteries are direct current. D.C. voltage can be
measured by holding the positive and negative leads of a
D C voltmeter on the corresponding terminals of the D.C.
device such as a battery. Direct current usually is not found
in higher voltages (over 24 volts) around plants except in
motor-generator sets. Care must be taken when installing
battery cables and wiring that Positive (-f ) and Negative (-)
poles are connected properly to wires marked (-f ) and (-). If
not properly connected, you could get an arc of electricity
across the unit that could cause an explosion

18. 1 13 Alternating Current (A.C.)

An alternating current circuit Is one in which the voltage
and current periodically change direction and AMPLITUDE.^
In other words, the current goes from zero to maximum
strength, back to zero and to the same strength in the
opposite direction. Most A.C. circuits have a frequency of 60
CYCLES^ per second. "Hertz" Is the term we use to describe
the frequency of cycles completed per second so our A.C.
voltage would be 60 Hertz (Hz).

Alternating current is classified as:

a. Single phase,

b. Two phase, and

c Three phase, or polyphase.

The most common of these are single phase and three
phase. The various voltages you probably will find on your
job are 1 1 0 volts, 120 volts, 208 volts, 220 volts, 240 volts,
277 volts, 440 volts, 480 volts, 2400 volts and 4160 volts.

Single-phase power is found in lighting systems, small
pump motors, various portable tools and throughout our
homes This power is usually 120 volts and sometimes 240
volts Single phase means that only one phase of power is
supplied to the mam electrical panel at 240 volts and has
three wires or leads. Two of these leads have 120 volts
each, the other lead is neutral and usually is coded white.
The neutral lead is grounded. Many appliances and power
tools have an extra ground (commonly a green wire) on the
case for additional protection.

Thiee-phase power is generally used with motors and
transformers found in water treatment plants, and usually is
208, 220, 240 volts, or 440, 460, 480 and 550 volts. Higher
voltages are used in sone pump stations. T^ ree phase is
used when higher power requirements or larger motors are
used because efficiency is usually higher and motors require
less maintenance. Generally speaking, all motors above two
horsepower are three phase unless there is a problem with
the power company getting three phase to the installations.
Three-phase power usually is brought in to the point of use
with three leads. There is power on all three leads and the
fuse switches will generally appear as shown in Figure 18.3.

Fig. 16.3 Fuse switches

(Courtesy of Consolidated Electrical Distributors, inc )

When making voltage measurements on three-phase
power circuits, take three readings: (1) between lead 1 and
lead 2, (2) between 1 and 3, and (3) between 2 and 3. The im-
balance between readings should not exceed five percent of
the average of the three readings and the average should
not be below the nominal voltage (20P 220, 240, 460) nor
should It exceed the nominal voltage by more than five
percent. Voltages that do not meet these limits will place
undue stress on electrical equipment, especially motors.

^ Electnaans often talk about .:oS'ng an electrical circuit. This means they are closing a switch that actually connects circuits together so
electricity can flow through the circuit. Closing an electrical circuit is like opening a valve on a water pipe.

2 Amplitude The maximum strength of an alternating current during its cycle, as distinguished from the mean or effective strength.

3 Cycle. A complete alternation of voltage and/or current in an alternating current (A.C.) circuit.

243

224 Water Treatment

When there is power in threp leads and a fourth lead is
brought in, it is a neutral lead Incoming power goes through
a metar and then some type of disconnecting switch This
switch could be a fuse switch or a circuit breaker The
purpose of the disconnect switch is to open whenever a
short or fault occurs and thus protect both the electrical
circuits and electncal equipment.

Circuit breakers (Figure 18.4) are used to protect electrical
Circuits from overloads. Most circuit breakers are metal
conductors that de-energize the mam circuit when excess
current passes through a metal stnp causing it to overheat
and open the mam circuit.

Fig. 16.4 Circuit breakers

(Courtesy oi Consolidated EiectrrCdl Distributors inc )

These equations are used by electrical engineers for
calculatmg circuit charactenstics If you memorize the fol-
lowmg relationship, you can always figure out the correct
formula

To use the above triangle you cover up the term you don't
know or are trying to find out with your finger. The relation-
ship between the other two known terms will indicate how to
calculate the unknown. For example, if you r s trying to
calculate the current, cover up I. The two knowns (E and R)
are shown in the triangle as E/R. Therefore, I = E/R. The
same procedure can be used to find E when I and R are
known or to find R when E and I are known.

Two-phase systems will not be discussed oecause they
are seldom found m water treatment facilities.

18.114 Amps

An Ampere (I) is the practical unit of electric current. This
IS the current produced by a pressure of one volt in a circuit
having a resistance of one ohm. Amperage is the measure-
ment of current or electron flow and is an indication of work
being done or "how hard the electricity is working."

In order to understand amperage, one more term must be
explained. The OHM is the practical unit of electrical resis-
tance (R). "Ohm's Law" states that in a given electrical circuit
the amount of current (I) in amperes is equal to the pressure
in volts (E) divided by the resistance (R) In ohms. The
followmg three formulas are given to provide you with an
indication of the relationships among current, resistance and
EMF (electromotive force).

BMP. Volts

Current, amps= r : :: —

Resistance, ohms

EMF. Volts = (Current, amps) (Resistance, ohms) ( E - IR )

Resistance,
ohms

EMF, Volts
Current, amps

(R = -)

ERIC

18.115 Watts

Watts (W) and kilowatts (kW) are the units of measurement
of the rate at which power is being used or generated. In
D.C. circuits, watts (W) equal the voltage (E) multiplied by the
current (I).

Power, watts - (Current, amps) (Electromotive Force, volts)

or P, v^/atts = (I. amps) (E, volts)

In A C polyphase circuits the formula becomes more
complicated because of the inclusion of two additional
factors. First, there is the square root of 3, for three-phase
circuits which is equal to 1.73. Secondly, there is the power
factor which is the ratio of the true or actual power passing
through an electncal circuit to the product of the voltage
times the amperage m the circuit, '^or standard three-phase
induction motors the power factor will be somewhere near
0.9. The formula for power input to a three-phase motor is:

Power, kilowatts

(E volts) (I. amps) (Power Factor) (1 73)
1000 watts/kilowatt

Since 0 746 kilowatts equal 1 .0 horsepower, then the power
output of a motor is

Power Output
horsepower

(Power Input, kilowatts) (Efficiency, %)
(0.746 kilowatts/horsepower) (100%)

244

Maintenance 225

18. 1 16 Power Requirements

Power requirements (Pr) are expressed in kilowatt hours
500 watts for two hours or one watt for 1000 hours equals
one kilowatt hour The power company charges so many
cents per kilowatt hour.

Power req., kW-hr = (Power, kilowatts) (Time, hours)
P?.kW-hr - (P, kVV) (T, r.r)

18.117 Conductors and Insulators

A material, like copper, which permits the flow of electrical
current k> called a conductor Material which will not permit
the flow ot electricity, like rubber, is called an insulator. Such
material when wrapped or cast around a wire is called
insulation. Insulation is commonly used to prevent the loss
of electrical flow by two conductors coming into contact with
each other.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 323.

18.11 A What are two types of current?

18.1 IB Amperage is a measurement of what?

18.1 1C How can you determine the proper voltage and
allowable current in amps for a piece of equipment*?

Be sure the voltage tester that you are using has sufficient
range to measure the voltage you would expect to find. In
other words do not use a tester with a limit of 600 volts on a
circuit that normally is energized at 2300 volts. With the
voltage tester you can tell If the current is A.C. or D.C. and
the intensity or voltage which will probably be one of the
following: 120, 207, 230, 460, 2400, or 4160.

Do not \A'0.*'k on sny 6!9Ctr!C3l circuits unless you are
qualified and authorized. Use a voltage tester and other
Circuit testers to determine if a circuit is energized, or if all
voltage is off. This should be done after the mam switch is
turned off to make sure it is safe to work inside the electrical
pa.iel. Always be aware of the possibility that even if the
disconnect to the unit you are working on is off, the control
circuit may still be energized if the circuit onginates at a
different distribution panel. Also a capacitor in the unit may
have sufficient energy stored to cause considerable harm to
an operator, such as a power factor correction capacitor on
a motor. Test for voltage both before and during the time the
switch IS pulled off to have a double check. This procedure
ensures that the voltage tester is working and that you have
good continuity to your tester. Use circuit testers to measure
voltage or current characteristics to a given piece of equip-
ment and to make sure that you have or do not have a live"
circuit.

Besides using the voltage tester for checking power, it can
be used to test for open circuits, blown fuses, single phasing
c' Mors, grounds, and many other uses. Some examples
are illustrated in the following paragraphs.

In the Circuit shown below (Figure 18.5), test for power by
holding one lead of the tester on point "A," and the other at
point "B." If no power is indicated, the switch Is open or
faulty. Sketch shows switch in "open" position.

Light

Switch

Ground

18.12 Tools, Meters and Testers

NieveC ^MT&C AN eu&CT(2lCALPAMeL
Qe(PM(2 ASii^ p\BCJ^ Of BlBCmc/Kl^

MMH0(Z\7BrP.

18.120 Voltage Testing

In order to maintain, repair, and troubleshoot electrical
equipment and circuits, the proper tools a^'e required. You
will need a VOLTAGE TESTER to check for voltage. There
are several types on the market and all of them work. They
are designed to be used on energized circuits and care must
be exercised when testing. By holding one lead on ground
and the other on a power lead, you can determine if the
circuit is energized.

ERLC

Fig. 18.5 Single-phase circuit (switch in open position)

To test for power at Point "A" and Point "B" in Figure 18.6,
open the switch as shown. Using a volt meter or voitage
tester, connect a lead on Line 1 and a lead on Line 2, at
points A and B, between the fuses and the load. Bring the
voltage tester and leads out of the panel and close the panel
door as far as possible without cutting or damaging the
meter leads. Some switches cannot be closed if the panel
door IS open. The panel door is closed when testing because
hot copper sparks could seriously injure you when the circuit
IS energized and the voltage is high. Close the switch.

1. Voltage tester should register at 220 volts. If there is no
reading at points "A" and "B," the fuse or fuses could be
blown.

2. Move voltage tester to LI and L2. If there is still no
reading on the voltage tester, check for an open switch in
another location, or call the power company to find out if
power is out.

24H

226 Water Treatment

LINE

NEUTRAL

INCOMING
SINGLE PHASE 220 VOLT
(110 VOLTS FROM N TO LI AND
110 VOLTS FROM N TO L2
220 VOLTS FROM LI TO L2
OR A TO B)

SWITCH

FUSES

LOAD

Fig, 18.6 Single-phase, three lead circuit

3. If a 220 volt reading is registered at LI and 12, move the
test leads to pent "A," and the "neutral" lead If a reading
of 110 volts is observed, the fuse on line "A" is okay. If
there isn't a voltage reading, the fuse on line "A" could be
"blown." Move the lead from line "A" to line "B." Observe
the reading. If 110 volt power is not observed, the fuse on
line "B" tould be "blown." Another possibility to consider
IS that the neutral line could be brohan. Under these
conditions, if there is voltage on line "A" and the fuse on
line "B" is blown, voltage may appear on line "B."

WARNING

TURN OFF POWER AND BE SURE THA T THERE IS
NO V^LT^GE IN EITHER POWER LINE BEFORE
CHANGIN3 FUSES. Use a FUSE PULLER. Test circuit
again in the same manner to make sure fuses or circuit
breakers are okay. 220 volts power or voltage should
be present between points "A" and "B." If fuse or circuit
breaker trips again, shut off and determine the source
of the problem.

Referring to Rgure 18.7, test for voltage in three-phase
circuits as follows — with the switch closed and the load
disconnected, check for voltage (probably either 220 or 440)
between points A3-B3, A3-C3, and between B3-C3. A zero
voltage reading on any or all of the three tests indicates a
problem ahead of this location that could be at another

switch or a power company problem. Assuming normal
readings were found at A3, B3, and 03, repeat the three
readings at points A2, B2, and 02 with the switch closed.
Any zero voltage readings are an indication of a defective

ER?C

24i>

Maintenance 227

FUSES

L2
LOAD

Fig. 18.7 Three-phase circuit, 220 volts

switch. Assummg normal readings were found at A2, B2,
and C2, repeat the three readings at points A1 , B1 , and C1
with the switch closed. If any two voltage readings are zero,
one fuse is blown and it will be the one in the line that was
common to the two zero readings. If aii three voltage
readings are zero, either two or three fuses are blown. To
determine which fuses are blown, refer to Table 18.1. Note
that a zero voltage reading indicates a blown fuse.

TABLE 18.1 LOCATING A BLOWN FUSE
Blown Fuse In Line Use Either Test

LI A1-B2or A1-C2

L2 B1-A2 or B1-C2

L3 C1-A2orC1-B2

Another way of checking the fuses with the load connect-
ed on this three-phase circuit would be to take your voltage
tester and place one lead on the bottom and one lead on the
top of each fuse. You should NOT get a voltage reading on
the voltmeter. This is because electricity takes the path of
least resistance. If you get a reading across any of the fuses
(top to bottom), that fuse is bad.

ALWAYS MAKE SURE THAT WHEN YOU USE A VOLT-
METER IT IS SET FOR THE PROPER VOL TAGE. IF VOLT-

AGE IS UNKNOWN AND THE METER HAS DIFFERENT
SCALES THAT ARE MANUALLY SET, ALWAYS START
WITH THE HIGHEST VOLTAGE RANGE AND WORK
DOWN. Otherwise the voltmeter could be damaged. Look at
the equipment instruction manual or name plate for the
expected voltage. Actual voltage should not be much higher
than given unless someone goofed when the equipment was
v^ired and inspected.

18. 121 Ammeter

Another meter used in electrical maintenance and testing
IS the AMMETER. The ammeter records the current or
"amos" flowing in the circuit. There are several types of
ammeters, but only two will be discussed in this section. The
ammbt^^r generally used for testing is called a "clamp on"
type. The term "clamp on" means that it can be clamped
around a wire supplying a motor, and no direct electrical
connection need be made. Each "leg" or lead on a three-
phase motor must be individually checked.

The first step should be to read the motor name plate data
and find what the amperage reading should be for the
particular motor or device you are testing. After you have
th's infornr.atlon, set the ammeter to the proper scale. Set it
on a higher scale than necessary if the expected reading is
close (o the top of the meter scale. Place the clamp around
one lead at a time. Record each reading and compare with
the name plate rating. If the readings are not similar to the

24';

228 Water Treatment

name plate rating, find the cause, such as low voltage, bad
bearings, poor connections or excessive load. If the amme-
ter readings are higher than expected, the high current could
produce overheating and damage the equipment. Try to find
the problem and correct it.

Current imbalance is undesirable because it causes un-
even heating in a motor that can shorten the life expectancy
of the insulation. However, a small amount of current
imbalance is to be expected in the leads to a three-phase
motor. This Imbalance can be caused by either peculiarities
in the motor or by a power company imbalance. To isolate
the cause, make the following test. Note that this test should
be done by a qualified electrician. Refer to Figure 18.8.

If the current on Lines L1, L2, and L3 are about the same
both before and after the winng change, this is an indication
that the imbalance is being caused by the power company
and they should be asked to make adjustments to correct
the condition. However, if the current reading followed the
motor terminal (T) numbers rather than the power line (L)
numbers, the problem is within the motor and there isn't
much that can be done except contact the motor manufac-
turer for a possible exchange.

When using a clamp on ammeter, be sure to set the meter
on a high enough range or scale for the starting current if
you are testing during startup. Starting currents range from
500 to 700 percent higher than running currents and using

LINE

L1 L2

o 6

MOTOR
STARTER

T1 T2

Ftg. 18.8 Determination of current imbalance

1. With the motor wired to its starter, L1 to T1, L2 to T2 and
L3 to Y3, measure and record the amperage on L1 L2
and L3.

2. De-energIze the circuit and reconnect the motor as fol-
lows: L1-T3, L2-T1, L3-T2. This wiring change will not
change the direction of the rotation of the motor.

3. Start up the motor and again measure and record the
amperage on L1 , L2, L3.

243

Maintenance 229

too low a range can rum an expensive and delicate instru-
ment Newer clamp on ammeters automatically adjust to the
proper range and can measure both starting or peak current
and normal running current.

Another type of ammeter is one that is connected m line
With the power lead orieads Generally they are not portable
and are usually installed in a panel or piece of equipment
They require physical connections to put them in series with
the motor or apparatus being tested Current transformers
(CT) are commonly used with this type of ammeter so that
the meter does not have to conduct the full motor current
These ammeters are usually more accurate tha*^. the clamp
on type and are used in motor control centers and pump
panels

18. 122 Megger

A MEGGER is a aevice used for checking the insulation
resistance on motors, feeders, buss bar systems, grounds,
and branch circuit winng.

— j WAKMNG I

There are three general types of meggers crank operat-
ed, battery operated, and instrument There are two leads to
connect One lead is clamped to a ground leac md the other
to the lead you are testing The readings on uie megger will
range from 0" (ground) to Infinity (perfect), depending on the
condition of your circuit.

The megger is usually connected to a motor terminal at
the starter, and the other lead to the ground lead. Results of
this test indicate if the insulation is deteriorating or cut

Insulation resistance of electrical equipment is affected by
many variables such as the equipment design, the type of
insulating material used, including binders and impregnatmg
compounds, the thickness of the insulation and its area,
cleanliness (or uncleanliness), moisture, and temperature
For insulation resistance measurements to be conclusive in
analyzing the condition of equipment being tested, these
variables must be taken into consideration.

Such factors as the design of the equipment, the kind of
insulating material used, and its thickness and area cease to
be vanables after the equipment has been put into service,
and minimum insulation resistance values can be estab-
lished within reasonable tolerances. The vanables that must
be considered after the equipment has been put into service,
and at the time that the ir'sulation resistance measurements
are being made, are uncloanliness, moisture, temperature,
and damage such as fractures

The most important requirements in the reliable operation
of electrical equipment are cleanhness and the elimination of
moi:*'ire penetration into the insulation. This is merely good
housekeeping but »t is essential in the maintenance of all
types of electrical equipment. The very fact that insulation
resistance is affected by moisture and dirt, with due
allowances for temperature, makes the 'megger" insulation
test the valuable tool which it is in electncal maintenance.

The test is an indication of cleanliness and good housekeep-
mg as well as a detector of deterioration and impending
trouble

Several cr.iaria for "minimum values' of insulation resis-
tance have been developed. These values should be pro-
vided by the equipment manufacturer and should serve as a
guide for equipment m service. However, penodic tests on
equipment in service will usually reveal readings consider-
ably higher than the suggested minimum safe values Rec-
ords of penodic tests must be kept, because persistent
downward trends m insulation resistance usually give fair
warning of impending trouble, even though the actual values
may be HIGHER than the suggested minimum safe values.

Also, allowances must be made *or equipment in service
showing penodic test values LOWER than the suggested
minimum safe values, so long as the values remain stable or
consistent In such cases, after due consideration has been
given to temperature and humid»ty conditions at the time of
the test, there may be no need for concern. THIS CONDI-
TION MAY BE CAUSED 3Y UNIFORMLY DISTRIBUTED
LEAKAGES OF A HARMLESS NA TURE. AND MAY NOT BE
THE RESULT OF A DANGEROUS LOCALIZED WEAK-
NESS Here again, records of insulation resistance tests
over a penod of time reveal changes which may justify
investigation. The "trend of the curve" may be more signifi-
cant than the numerical values themselves

For many years ONE MEGOHM"^ has been widely used as
a fair allowable lower limit for insulation resistance of
ordinary industrial electrical equipment rated up to 1000
volts. This value is still recommended for those who may not
be too familiar with insulation resistance testing practices, or
who may not wish to approach the problem from a more
technical point of view

For equipment rated above 1000 volts, the "one megohm"
rule IS usually stated. "A minimum of one megohm per
thousand volts' Although this rule is somewhat arbitrary.

and may be criticized as u .mg an engmeenng foundation.
It has stood the test of a good many year.i of practical
experience. This rule gives some assurance that equipment
IS not too wet or not too dry and has saved many an
unnecessary breakdown.

More recent studies of the problem, however, have result-
ed m formulas for minimum values of insulation resistance
that are based on the kind of insulating matenal used and
the electncal and physical dimensions of the types of
equipment under consideration '

^ Megohm Meg means one mtHion, so 5 megohms means 5 million ohms A megger reads in millions of ohms

5 Portions of the preceding paragraphs were taken from INSTRUCTION MANUAL FOR MEGGER INSULATION TESTERS, No

pages 42 and 43, published by Biddle Instruments, c/o Advertising Department, 510 Township Line Road, Blue Bell Pennsylvania

19422. For additional information see Biddle's publication, A STITCH IN TIME, price $2.00

ERIC

24.9

230 Water Treatment

Motors and wirings should be megged at least once a
year, and twice a year if possible. The readings taken should
be recorded and plotted in some manner so that you can
determine when insulation is creaking down. Meg motors
and wirings after a pump station has been flooded. If
insulation is wet, excessive current could be drawn and
cause pump motors to "kick out "

18,123 Ohm Meters

OHM MEIERS, sometimes called circuit testers, are valu-
able tools used for checking electrical circuits. An ohm meter
IS used only when the electrical circuit is OFF, or de-
energized The ohm meter supplies its own p'^wer by using
batter es An ohm meter is used to measure the resistance
(ohms) in a circuit These are most often used in testing the
control circuit components such as coils, fuses, relays,
resistors, and switches. They are used also to check for
continuity An ohm meter has several scales which can be
jsed Typical scales are: R a 1 , R ^ 10. R a i ,000, and R x
1 0,000. Each scale has a level of sensitivity for measuring
different resistances. To use an ohm meter, set the scale,
start at the low point (R x 1). and put the two leads across
the part of the circuit to be tested such as a coil or resistor
and "ead the resistance In ohms. A reading of infinity would
indicate an ^pen circuit, and a "0" would read no resistance.
These usually would be used only by skilled technicians
because they are very delicate instruments.

All meters should be kept in good working order and
calibrated periodically They are very delicate, susceptible to
damage, and should be well protected during transportation.
When readings are taken, they should always be recorded
on a machinery history card for future reference. Meters are
a good way to determine pump and equipment perform-
ance. NEVER USE A METER UNLESS QUALIFIED AND
AUTHORIZED.

QUESTIONS

Write your answers m a notebook and then compare your
answers with those on page 323.

1812A How can you determine if there is voltage in a
circuit

18.12B What are some of the uses of a voltage tester'^

18.12C What precautions should be aken before attempt-
ing to change fuses'?

18.12D How do you test for voltage with a voltmeter when
the voltage is unknown?

1 8.12E What could be the cause of amp readings different
from the name plate rating?

18.12F How often should motors and wirings be megged*?

18 12G An ohm meter is used to check the ohms of
resistance in what control circuit components?

18.13 Switch Gear

18. 130 Equipment Protective Devices

Electricity needs safety devices to protect operators and
equipment Water systems have pressure valves, pop offs
and different safety equipment to protect the pipes ant-
equipment. So must electricity have safety devices to con-
tain the voltage and amperage that r^omes in contact with the
wiring and equipment. The first piece J equipment which
must be protected is the main electrical panel or control unit

where the power enters. Thjs protection is provided by
either fuses or a circuit breaker

18.131 Fuses

Let s start with fuses The power company has installed
fuses on their power noles to protect ^heir equipment from
damage We also must insta'i something to protect the mam
control panel and wiring from damage due to excessive
voltage or amperage

A FUSE IS a protective device having a stnp or wire of
fusible metal which, when placed in a circuit, will melt and
break the electnca! circuit when subjected to an excessive
temperature This temperature will develop in the fuse when
a current flows through the fuse in excess of what the circuit
will carry safely This means that the fuse must be capable of
de-energizing the circuit before any damage is done to the
wiring it is safely protecting. Fuses are used to protect
operators, mam circuits, branch circuits, heaters, motors,
an^ arious other electrical equipment.

I cie are several types of fuses, each being used for a
certain type of protection. Some of these are:

1 CURRENT-LIMITING FUSES. These fuses open so
quickly while cleanng a short-circuit current that the
potential fault current is not allowed to reach its peak.
They are used to protect power distribution circuits.

2 DUAL-ELEMENT FUSES: These fuses provide a time
delay in the low overload range and a fast acting element
for short-circuit protection. These fuses are used for
motor protection circ jits.

There are many other types of fuses used for special
application, but the above are the most common.

A fuse must NEVER be by-passed or jumped. This is the
only protection the circuit has; without it, senous damage to
equipment and possible injury to operators can occur. Make
sure that all fuses are replaced with the proper size and type
mdicated for that circuit. If you have any doubt, check the
electrical pnnts or contact your electrical engineer.

18, 132 Circuit Breakers

The CIRCUIT BREAKER (Figure 18.4) is another safety
device and is used in the same place as a fuse. Most circuit
breakers consist of a switch that opens automatically when
the current or the voltage exceeds or falls below a certain
limit. Unlike a fuse that has to be replaced each time it
"blows," a Circuit breaker can be reset after a short delay to
allow time for cooling. This is done by moving the handle to
the "off" position or slightly past, and then moving it back to
the "on" position. Also, unlike a fuse, a circuit breaker can be
visually inspected to find out if it has been tripped. The

2i)0

ERiC

Maintenance 231

handle will be at the mid position between 'on" and off/
Several different types of circuit breakers are being used
today and each one is selected for a ^ jcial protective
purpose.

18. 133 Overload Relays

Three-phase motors are usually protected by OVERLOAD
relays. This is accomplished by having heater strips, bimetal,
or solder pots which open on current rise (overheating), and
open the control circuit. This in tum opens the power control
Circuit, which de-energizes the starter and stops power to
the motor. Such relays are also known as heaters or
thermal overloads. Sizing of these overloads is very cntical
and should co'ncide with the name plate rating on the motor.
Sizing depends on the servic ? factor of the electnc motor.
Usually they range from 100 to 110 percent of the motor
name plate ratings and should never exceed 125 percent
("sually 1 15 percent) of the motor rating. For example, if the
motor IS rated for 10 amps, the overloads should be sized
from 10 to 11 amps.

Again. NEVER INCREASE ^-iE RATING OF THE OVER-
LOAD HEATERS BECAUSE OF TRIPPING, YOU SHOULD
FIND THE PROBLEM AND REPAIR IT. There are many
other protective devices for electricity such as motor wind-
ing thermostats, phase protectors, low voltage protectors,
and ground fault protectors. Each has its own special
applications and should never be tampered with or jammed.

GROUND IS an expression representing an electrical
connection to earth or a large conductor which is at the
earth's potential or neutral voltage. Motor frames and all
electrical tools and equipment enclosures should be con-
nected to ground. This is generally referred to simply as
grounding, or equipment ground.

The third prong on cords from electric hand tools is the
equipment ground and must never be removed. When an
adapter is used with a two-prong receptacle, the green wire
on the adapter should be connected Uiider the center screw
on the receptacle cover plate. Many times equipment
grounding, especially at home, is achieved by connecting
onto a water pipe or drain rather than a rod driven into the
ground. This practice generally is not recommended when
pk^stic pipes and other non-conducting pipe matenals are
used unless it is known that the piping is all metal and not in-
terrupted. Also corrosion can be accelerated pipes of
different metals are used. A rod dnven into dry ground isn't
very effective as ? ^round.

18.134 Motor Starters

A motor starter is a device or group of devices which are
used to connect the electrical power to a motor. These
starters can be either manually or automatically controlled.

Manual and magnetic starters range in complexity from a
single "on-off" switch, to a sophisticated automatic device
using timers and coils. The simplest motor starter is used on
single-phase motors where a circuit breaker is turned on
and the motor starts. This type of starter also is used on
three-phase motors of smaller horsepower. These are used
on fan motors, machinery motors, and several others where
It isn't necessary to have automatic control.

MAGNETIC STARTERS (Figures 18.9 and 18.10) are
commonly used to start pumps, compressors, blowers, and
anything where automatic or remote control is desired. They
permit low power circuits to energize the starter of equip-
ment at a remo\e location or to start larger starters (Figure
18.11). A magnetic starter is operated by electromagnetic

ERIC

action This starter has contractors and tney operate by
energizing a coil which closes the contact, thus starting the
motor The circuit which energizes the starter is called the
control Circuit and it may operate on a lower voitage (115
volts) than the motor. Whenever a starter is used as a part of
an integrated circuit (such as *or flow, pressure or tempera-
ture control), a magnetic starter or controller is necessary.

Magnetic starters are sized for their voltage and horse-
power ratings These are divided into classes The nosi
cc nmon starts*- is Class "A." A Class "A" starter is an
Alternating Current air-break and oil immersed ma iual, or
magnetic controller for service on 600 volts or le*>s. It is
capable of interrupting operating overloads up to and .pclud-
ing 10 tinpes their normal motor rating, but not short circuits
or faults beyond operating overloads."

Additional class information can be found in electrical
catalogs, manuals and manufacturers' brochures.

There are a number of different types of three-phase
magnetic motor starters available. The simplest and most
common is the "across-the-line" full voltage starter. This
starter consists of three contacts, a magnetic actuating
device, and overload detection. This starter subjects the
power system to the full surge current on startup and may
cause the lights in the treatment plant to dim momentarily.

To reduce the in-rush current when starting polyphase
motors, a number of other types of starters are available.

1 . Auto-Transformer Type Reduced Voltage Starters. These
begin the motor start sequence by applying a reduced
voltage to the motor for a few seconds. The voltage is
controlled by a time delay relay within the starter. The
reduced voltage is obtained from transformers that are a
part of the starter. These transformers are designed to
operate for only a few seconds at a time and can easily be
burned out if the motor is started too frequently.

2 Solid State Reduced Voltage Starters. These starters do
the same job as the auto-transformer type reduced
voltage starters but they do not need transformers be-
cause the voltage and current are electrically controlled.

3 Part Winding Starters. These starters are used with
special motors that have two separate sets o^ windings
on the same motor frame. By energizing the windings
about one second apart, the in-rush current is limited to
about half that of a normal motor with a full voltage
starter.

4. Wye-Delta Starters. These starters are used with motors
that have all leads brought out to the terminal box. The
motor IS first started with wye connected coils and
switched over to a aelta connection for running, "^he
result IS the same as if you used a reduced voltuge
starter.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 323.

1 8 1 3A What are two types of safety devices found in main
electrical panels or control units''

18.13B What are fuses used to protect?

18.13C Why must a fuse never be by-passed or jumped?

18.1 3D How does a circuit breaker work?

18.13E How are motor starters controlled?

18.13F When are magnetic starters used?

232 Water Treatment

Maintenance 233

Fig. 18.10 Wiring diagram of three-phase magnetic starter

Fig. 18. 1 1 Application of magnetic starter

253

234 Water Treatment

18.14 Electric Motors

18.140 Classification

Electric motors are the machines most commonly used to
convert electrical energy into mechanical energy. A motor
usually consists of a STATOR,^ ROTOR J END BELLS,^ and
windings. The rotor has an extending shaft which allows a
machine to be coupled to it.

Motors are of many different types (Figure 1 8. 1 2), such as,
squirrel cage induction motors, wound rotor motors, syn-
chronous motors and many others. The most common of
these IS the squirrel cage induction motor. Some pumping
stations use wound rotor induction motors when speed
control IS nieded

Three-phase electric motors are used for operating
pumps, compressors, fans and other machinery. Motors are
generally trouble free and, when lubricated properly, cause
very few problems The amperage and voltage readings on
motors should be taken periodically to insure proper oper-
ation

Motors are classified by NEMA (National Electrical Manu-
facturers Association) with code letters from A through V
With "A" having the lowest starting torque and in-rush current
and "V having the highest starting torque and in-rush
current The most commonly available motors have codv.-
letters from "F" through "L" which have in-rush currents on
start of from 500 to 1000 percent of full load.

Another important consideration in selecting a motor is
the class of insulation. This determines how hot a motor may
operate and is listed as degree rise on the motor nameplate
(Figure 18.13).

Motor insulation classt^ are as follows:

Class

Temperaturing Rating

105°C (221 °F)

130°C (266°F)

155°C (31 rF)

180°C (356°F)

At pre'^ent most motors are Class B insulated. Try to keep
the actual operating temperature below the temperature
rating or limit in order to prolong the life of the insulation.

All of this information can be found on the motor name
plate and should be taken Into consideration when evaluat-
ing a motor. Most of the trouble encountered with electrical
motors results from bad bearings, shorted windings due to
insulation breakdown or excessive moisture.

All of the information on the motor name plate (Figure
18.13) should be recorded and placed in n file for future
reference. Many times the name plate is painted, corroded
or missing from the unit when the information is needed to
repair the motor or replace parts. Also record the date of
installation and service startup. See Section 18.142. "Rec-
ordkeeping.*' for a typical data sheet for recording the
essential information. This information also should be on the
manufacturer's data sheet and in the instruction manual.
Compare the information for consistency and file in an
appropriate location. Be sure you have the correct serial
and/or model numbers.

QUESTIONS

Wnte you*- answers in a notebook and then compare your
answers with those on page 324.

18 14A How IS electncal energy converted into mechanical
energy*?

18.14B What are the important parts of an electnc motor?

18 14C How can motors be kept trouble free?

18.14D What should be done with motor name plate data*?

18. 14 1 Troubleshooting

Practical stop-by-step procedures combined with a com-
mon sense approach is the key to effective troubleshooting.

A. Gather preliminary information. The first step in trouble-
shooting any motor control which has developed trouble
IS to understand the circuit operation and other related
functions. In other words, what is supposed to happen,
operate, and so forth when it's working right? Also, what
IS It doing now? The qualified maintenance operator
should be able to do the following:

1 . KNOW WHAT SHOULD HAPPEN WHEN A SWITCH IS
PUSHED: V^hen switches are pushed or tripped, know
what coils go in, contacts close, relays operate, and
motors run.

2. EXAMINE ALL OTHER FACTORS: What other unusual
things are happening in the plant now that this circuit
doesn't work properly? Lights dimmed, other pumps

stor ed, lights went out when it broke, everything was
flooded, operators were hosing down area, and many
other possible factors.

3. ANALYZE WHAT YOU KNOW: What part of it is
working correctly? Is switch arm tripped? Is it a
mechanical failure or an electrical problem caused by
a mechanical failure?

4. SELECT SIMPLE PROCEDURES: To localize the
problem, select logical ways that can be simply and
quickly accomplished.

5. MAKE A VISUAL INSPECTION: Look for bumed
wires, loose wires, area full of water, coil burned,
contacts loose, or strange smells.

« Stator That portion of a machine which contains the stationary (non-moving) parts that surround the moving parts (rotor)

liotor The rotating part of a machine. The rotor is surrounded by the stationary (non-moving) parts (stator) of the machine
» End Bells. Devices used to hold the rotor and stator of a motor in position.

er|c

254

Maintenance 235

DRIP PROOF

ITEM
NO.

PART NAME

Wound Stator w/ Frame

Rotor Assembly

Rotor Core

Shaft

Bracket

Bearing Cap

Bearings

Seal, Labyrinth

Thru Bolts/Caps

Seal, Lead Wire

Terminal Box

Terminal Box Cover

Fan

Deflector

Lifting Lug

TOTALLY ENCLOSED FAN COOLED

ITEM
NO.

PART NAME

Wound Stator w/ Fvame

Rotor Assembly

Rotor Core

Shaft

Brackets

Bearings

beal. Labyrinth

Thru Bolts /Caps

Seal, Lead Wire

Terminal Box

Terminal Box Cover

Fan, Inside

Fan, Outside

Fan Grill

Fan Cover

Fan Cover Bolts

Lifting Lug

Fig. 18. 12 Typical rr.^tors

"curtesy of Sterling Power Systems. Inc ;

Er|c 2^l\

236 Water Treatment

Sterlii

£/7/^ VARIABLE SPEED

SERIAL NO. B-961Q283

DESIGN B

FRAME

215

MAX
AM8

CLASS

ABFK

DUTY Continuous

oc!

TYPE

NOTE- 1. The motor for this unit is rated at 1750 RPM and
the maximum speed for the vanable drive unit is
1200 RPM.

2. The 40°C rating is V\e allowable operating tem-
perature above ambient tempera'ure.

Fig. 18. 13 Typical nameplate

(Courtesy of Sterling Power Systems. Inc.)

6 CONVERGE ON SOURCE OF TROUBLE: Mechanical
or electrical. Motor or control, whatever it might be
Electncal problems result from some type of mechani-
cal failure.

7 PINPOINT THE PROBLEM. Exactly where is the prob-
lem and what do you need for repair?

8. FIND THE CAUSE. What caused the problem*? Mois-
ture, wear, poor design, voltage, or overloading.

9. REPAIR THE PROBLEM AND ELIMINATE THE
CAUSE IF POSSIBLE. If the problem is inside switch
gear or motors, call an electrician. Give the electrician
the information you have regarding the equip'^ent. Do
not attempt electrical repairs unless qualified and
authorized, otherwise you could cause excessive
damage to yourself and to the equipment.

B Some of the things to look for when troubleshooting are
given in the remainder of this section,

ERIC

18. 142 Recordkeeping

Records are a very important part of electncal mainte-
nance They must be accurate and complete. Whenever
something is changed, repaired, or tested, it should be
recorded on a material history Cc ''d of some type. Pages 242
and 243 are examples of typical record sheets

QUESTIONS

Write your answers m a notebook and then compare your
answers with those on page 324.

18 14E What IS the key to effective troubleshooting*?

18.14F What are some of the steps that should be taken
when troubleshooting electrical equipment?

18 14G What kind of information should be recorded re-
garding electncal equipment?

Maintenance 237

ELECTRIC MOTOR TROUBLESHOOTING
1. Contacts

Trouble Possible Causes

Contact chatter 1 . Broken POLE SHADER ^

2. Poor contact in contro! circuit.

3. Low voltage

Welding or freezing 1. Abnormal surge of current.

2. Frequent JOGGING:^

3. Insufficient contact pressure.

Short contact hfe or overheating
of tips

Coil, overheated

4. Contacts not positioning properly.

5. Foreign matter preventing magnet
from seating.

6. Short cir^ Jit

1- Contacts poorly aligned, spaced or
damaged.

3. Excessive starting and stopping of
motor.

4. Weak contact pressure.

5. Dirty contacts.

6. Loose connections.

1. Starting coil may not kick out

2. Overload won't let moior reach mini-
mum speed.

3. Over voltage or high ambient tem-
perature.

4. Incorrect cor'

5. Shorted turns caused by mechanical
damage or corrosion.

6. Undervoltage, failure of magnet to
seal It.

7. Dirt or rust on pole faces increasing
air gap.

Remedy

1. Replace

2. Improve contact or use holding circuit
Interlock

3. Correct voKage condition. Check mo-
mentary voltage dip.

1. Use larger contactor and check for
grounds, shorts, or excessive motor
load current.

2. Install larger device rated for jogging
service or caution operator.

3. Replace contact spnng; check contact
carrier for damage.

4. Check for voltage dip during startup.

5. Clean contacts.

6. Remove short fault and check that
fuse or breaker are right.

1. Do not file silver-faced contacts.
Rough spotfi or discoloration will not
harm contacts.

2. Install larger device. Check for
grounds, shorts, *r excessive motor
currents.

3. Caution operators. Check operating
controls.

4. Adjust or replace contact spnngs.

5. Clean with approved solvent.

6. Check terminals and tighten.

1. Repair coil.

2. Remove overload.

3. Check application and circuit.

4. Check rating and if incorrect, replace
with proper coil.

5. Replace coil.

6. Correct system voltage.

7. Clean pole faces

2. EA^s:"<5'vely high currents.

9 Poie Shader. A copper bar circling the laminated iron core inside the coil of a magnetic starter.
Jogging. The frequent starting and stopping of an electric motor.

238 Water Treatment

ELECTRIC MOTOR TROUBLESHOOTING ('Continued)
Trouble Possible Causes

Overload relays tripping 1 Sustained overload

Failure to tnp overload relay

2. Loose connection on all or any load
wires.

3 Incorrect heater

4. Fatigued heater blocks.

1. Mechanical binding, dirt, or corrosion.

2. Wrong heater, or heaters omitted and
jumper wires used

3. Motor and relay in different tempera-

tUicG

2. Magnetic and Mechanical Parts
Noisy magnet (humming)

Failure to pick up and seal

1 Broken shading coil.

2. Magnet faces not mating.

3. Dirt or rust on magnet faces.

4. Low voltage.

1 . Low voltage

2. Coil open or shorted.

3. Wrong coil.

4. Mechanical obstruction

Failure to drop out 1 . Gummy substance on pole

2. Voltage not removed from coil.

3. Worn or rusted parts causing binding.

4. Residual magnetism due to lack of air
gap in magnet path.

5 Welded contacts.

Remedy

1. Check for grounds, shorts or exces-
sive motor currents Mechanical over-
load

2 Check, clean, and tighten.

3. Replace with correct size heater unit.

4. Inspect and replace
1 Clean or replace.

2. Check ratings Apply heaters of prop-
er rating.

3. Adjust relay rating accordingly, or in-
stall temperature compensating re-
lays.

1. Replacing shading coil.

2. Replace magnet assembly or realign

3 Clean and realign.

4. Inspect system voltage and voltage
dips during starting.

1 Inspect system voltage and correct.

2. Replace.

3. Check coil number and voltage rating.

4. With power otf. check for free move-
ment of contact and armature assem-
bly. Repair.

1. Clean with solvent.

2. Check coil Circuit.

3. Replace or clean parts as necessary.

4. Replace worn magnet parts or align if
possible.

5 Replace contacts.

ERIC

253

Maintenance 233

TROUBLESHOOTING GUIDE FOR ELECTRIC MOTORS

Symptoms

Cause

Result*

Remedy

'i Motor ^oes not
start. (Switch is on
and not defective )

a Incorrectly connected.

a Burnout.

a Connect correctly per diagram
on motor

b. Incorrect power supply.

b Burnout

b Use only with correctly rated
power supply.

c. Fuse out. loose or open con-
nection.

c Burnout

c Correct open circuit condition.

d Rotating parts of motor may
be jammed mechanically

d. Burnout

d. Check and coirect:

1. Bent shaft.

2. Broken housing.

3. Damaged beanng.

d FnrPinn matprial in motor

e. Driven machine may be
jammed.

e. Burnout

e Correct jammed condition.

f. No power supply.

f. None.

f Check for voltage at motor and
work back to power supply.

!
1

g. Internal circuitry open.

g Fiurnout.

g. Correct open circuit condition.

i 2 Motor starts but

a. Same as 1-a, b, c above.

a. Burnout.

a. Same as 1-a, b, c above.

ooes not come up
to speed

b Overload.

b. Burnout.

b. Reduce load to bring cunent to
rated limit. Use proper fuses
and overload protection.

c. One or more phases out on
a 3 phase motor.

c. Burnout.

c. Look for open circuits.

1 3 Motor noisy electri-
! cally.

a. Same as 1-a, b, c above.

a. Burnout

a. Same as 1-a, b, c above.

! 4. Motor runs hot (ex-
j ceeds rating).

a. Same as 1-a. b, c above.

a. Burnout.

a. Same as 1-a, b, c above.

b. Overload.

b. Burnout.

b. Reduce load.

c. Impaired ventilation.

c. Burnout.

c Remove obstruction.

d. Frequent start or stop

d. Burnout

d. 1. Reduce number of starts or
reversals.
2. Secure proper motor for this
duty.

e. Misalignment between rotor
ana c^ator laminations.

e. Burnout

e. Realign.

5 Noisy

(mechanically)

a. Misalignment of coupling or
sprocket.

a. Bearing failure,
broken shaft, stator
burnout due to motor
drag.

a. Correct misalignment.

b. Mechanical unbalance of ro-
tating parts.

b. Same as 5-a.

b. Find unbalanced part, then bal-
ance.

c. Lack or improper lubricant.

c. Bearing failure

c. Use correct lubricant, replace
parts as necessary.

d. Foreign material in lubricant.

d. Same as 5-c.

d. Clean out and replace bear-
ings.

e. Overload.

e. Same as 5-c.

e. Remove overload condition.
Replace damaged parts.

f. Shock loading.

f. Same as 5-c.

f. Correct causes and replace
damaged parts.

g. Mounting acts as amplifier
of normal noise.

g. Annoying.

g. Isolate motor from base.

h. Rotor dragging due to worn
bearings, shaft or bracket.

h. Burnout.

h. Replacing bearings, shaft or
bracket as needed.

0 Dcdriny laiiure

a. oame as o^a, u, c, a, e.

a. ~UriiUUl, UaiTldycU

shaft, damaged hous-
ing.

a Qonl^r^o hparlt^riQ AnH fnllnuu
a. riCUiOiUc? ucai li IU9 ciiivJ iwii^w

a, b, c, d, e.

b. Entry of water or foreign ma-
tenal into beanng housing.

b. Same as 6-a.

b. Replace beorings and seais
and shield against entry of for-
eign material (water, dust, etc.).
Use proper motor.

* Many of these conditions should trip protective devices rather than burn out motors.

240 Water Treatment

TROUBLESHOOTING GUIDE FOR ELECTF MOTORS (continued)

Symptom

Caused By

A/'pearance

1 Shorted motor winding

a Moisture, chemicals, foreign material in
motor, damaged winding.

a. Black or burned with remainder of winding
good.

2 All windings completely
burned

a. Overload.

b. Stalled.

c. impaired ventilation.

d. Frequent reversal or starting

e. Incorrect power.

a. Burned equally all around winding

b Burned Pnurlllv rill ArmmH wmHinn

c. Burned equally all around winding
d Burned equally all around winding,
e. Burned equally all around winding.

3 Single phase cond ' n

a Open circuit in one line. The most common
causes are loose connection, one fuse
out, loose contact in switch.

a. If 1 800 RPM motor — four equally burned
groups at 90^ intervals.

b. If 1200 RPM motor — six equally burned
groups at 60** intervals

c. If 3600 RPM motor — two equally burned
groups at 180^

NOTE: If Y-connected each burned group
will consist of two adjacent phase groups.
If delta-connected each burned group will
consist of one phase group.

4 Other

a. Improper connection
b Ground.

a Irregularly burned groups or spot burns.

Many burnouts occur within a short period c . time after motor is started up This does not necessarily indicate that the motor was defec-
tive, but usually is due to one or more of the above mentioned causes The most common of these are improper connections, open circuits
in one hne, incorrect wer supply or overload

Maintenance 241

TROUBLE-REMEDY CHART FOR INDUCTION MOTORS

A. Motor will not start.

Overload control tripped. Waic for overload to cool, then
try to start again. If motor still does not start, check for the
causes outlined below.

1. Open fuses: test fuses.

2. Low voltage- check name plate value*} against power
supply characteristics. Also rheck voltage at motor
terminals when starting moi r under load to check
for allowable voltage drop.

3. Wrong control connections: check connections with
control wiring diagram.

4. Loose terminal-lead connection: turn power off and
tighten connections.

6. Drive machine locked: disconnect motor from load. If
motor starts satisfactorily, check dnven machine.

6. Open Circuit in stator or rotor winding: check for open
Circuits.

7. Short circuit in stator winding: check for short.

8. Winding grounded: test for grounded wiring

9. Bearing stiff: free bearing or replace.
10. Overload: reduce load.

8 Motoi noisy.

1. ';;»ree-phase motor running on single phase, stop
motor, then try to start. It will not start on single
phase. Check for open circuit in one of ♦ j lines.

2. Electrical load unbalanced: check current balance.

3. Shaft bumping (sleeve-bearing motor): check align-
ment and conditions of belt. On pedestal-mounted
bearing check cord play and axial centering of rotor.

4. Vibratiori: driven machine may U3 unbalanced. Re-
move motor from load If motor is still noisy, re-
balance.

5. Air gap not uniform: center tr . rotor arid if necessary
replace bearings.

6 Noisy ball bearing: check lubrication. Replace bear-
ings if noise is excessive and persistent.

7. Rotor rubbing on stator: center the rotor and replace
bearings if necessary.

8. Motor loose on foundation: tighten hold-down bolts.
Motor may possibly have to be realigned.

9. Coupling loose: insert feolers at four places in cou-
pling joint before pulling up bolts to check alignment.
Tighten coupling bolts securely.

C. Motor at higher than no*'mal temperature or smoking.
(Measure temperature with thermometer or thermister
and compare with name plate value.)

1. Overload: measure motor loading with ammeter.
Reduce load.

2. Electrical load unbalance: check for voltage unbal-
ance or single-phasing.

3. Restricted ventilation, clean air passage and wind-
ings.

4. Incorrect voltage and frequency: check name plate
values with power supply. Also check voltage at
motor terminals with motor under full load.

5. Motor stalled by driven tight bearings: remove power
from motor. Check machine for cause of stalling.

6. Stator winding shorted or grounded: test windings by
standard method.

7. Rotor winding with loose connection: tighten, if pos-
sible, or replace with another rotor.

8. Belt too tight: remove excessive pressure on bear-
ings.

9. Motor used for rapid reversing service, replace with
motor designed for this service.

D. Bearings hot.

1. End shields loose or not replaced properly: make
sure end shields fit squarely and are properly tight-
ened.

2. Excessive belt tension or excessive gear side thrust:
reduce belt tension or gear pressure and realign
shafts. See that thrust is not being transferred to
motor bearing.

3. Bent shaft: straighten shaft or senci to motor repair
shop.

E. Sleeve baarings.

1. Insufficient oil: a^d oil — if supply is very low, drain,
flush,and refill.

2. Foreign matenal in oil or poor grade of oil: dram oil,
flush, and relubricate using industrial lubricant rec-
omrr' :ded by a reliable oil manufacturer.

3. Oil rings rotating slowly or not rotating at all: oil too
heavy; dram and replace. If oil ring has worn spot,
replace with new ring.

4. Motor tilted too far: level motor or reduce tilt and
realign if necessary.

5. Rings bent or otherwise damaged in reassembling:
replace rings.

6. Rings out of slot (oil-ring retaining clip out of place):
adjust or replace retaining clip.

7. Defective bearings or rough shaft: replace bearings.
Resurface shaft

F. Bail bearings.

1. Too much grease: remove relief plug and let motor
run. If excess grease does not come out, flush and
relubncate.

2. Wrong grade of grease: flush bearing and relubncate
with correct amount of proper grease.

3. Insufficient grease: remove relief plug and grease
bearing.

4. Foreign material .i grease: flush bearing, relubricate:
make sure grease supply is clean (keep can covered
when not in use).

ERIC

261

242 Water Treatment

NAHE

TYPE

PUMP RECORD CARD

_MAKE

SIZE

MODEL

SERIAL #

ORDER NUMBER

SUPPLIER

DATE PURCHASED

DATE INSTALLED

APPLICATION

PLANT #

Naroe Plate Data and Pump Info Stuffing Box Data Motor Data

Diameter ^Depth Name Serial #_

TOH

RPM

Jype_

Gage Press Disc_

Gage P'-ess Sue

Shut off Press

Suction Head
Rotation

Impeller Type

Impeller Dia.

Impeller Clear

Coupl Type & Size

Front Brg I

Rear Brg #

Lub Interval
Lubricant

Wearing Rings

Shaft Sleeve Size

Pump Shaft Size

Pump Keyway

Other Related Information;

ERIC

Pack. Size_
Length No. Rings

H.P.

Speed

JLantern Ring Flushed

_Amb1ento_
RPM

Mech. Seal Name

Type_

Pump Materials

Shaft

_Wearing Rings Casing

JJearing Rings Impeller

Shaft Sleeve

JSlinger

Shims

_Gaskets_
"0" Rings

_Brg.- Seals Front_
Rear

asing Wear Ring Size ID_
OD

z W1dth__
Impeller Wear Ring ID_
0D_
Width,

Frame

Size Volts

_Amps_

Phase

jCycle^

Shaft Size

Key

_Bear1ng Front^
Rear

Code

Typt

J\mps (? Max. Speed

Jmps (? Shut Off

Control Data Info

Starter

MENA Size

Cat. §

Heater Size

Rated (?

J^ontrol Voltage

^Variable Speed
Typa_

Jpeed Max

JSpeed Miri_^

Maintenance 243

MOTOR STARTERS

Number

Title:.
Mfg.:_

Style:.
Type:_

Style_
Amps

Mfg:.

Style:

Cat. No.

TITLE_
Mfg:_
HP:

Phase:

Cycl es :.

Code:

S0#

Fonii

Address

Class

Size

O.L. HEATERS
Code

Mfg:.

O.L. TRIP UNITS
Style :_

Type:

Amps Range:

CIRCUIT BREAKER

Address

Frame:

_Volts;
Amps:

RPM:

S.F.:

Spec.

50 Cycle Data_

Volts

Amps Setting_

MOTOR

Number

Address

Ser. No.

Duty:

Frame:

Temp:

Jype_

Class;

Model

Spec . ;

Style:

CSA App:_

Shft. Brg.

Rear Brg.

Suitable for 208V Network: Connection Diagram

Additional data (6) (5) (4) (6) (5) (4)

(7) (8) (9) (7) (8) (9)

(1) (2) (3) (1) (2) (3)

ERIC

244 Water Treatment

18.15 Auxiliary Electrical Power
18.150 Safety First

Always remember that a QUALIFIED ELECTRICIAN
should perform most of the necessary maintenance and
repair of electrical equipment. If you don't know the how,
why, and when of the job, don't do it. You could endanger
your life as well as your fellow operators. Never attempt
work that you are not qualified to do or are not authonzed to
perform.

18, 15 1 Standby Power Generation

There are three ways of providing standby power. One is
by providing the treatment plant with an engine driven
generator set. The limit of how much power can be produced
IS determined only by the size of the generator. The second
possibility for standby power is batteries. Battenes should
only be considered for low power consumption uses such as
emergency lighting, communication, and possibly some con-
trol and instrumentation functions. The other possibility for
standby power is a connection to an alternate power source,
such as a different substation or another power company.

Because the treatment of water is considered a critical
service, it is important to be able to provide drinking water
even with the loss of commercial power. A power outage of
a short duration probably will not have adverse effects on
plant operation. The question you must ask yourself is, "Can
my plant meet the needs of the public if a 'brown out* or
catastrophic event eliminates commercial power for an
extended length of time?" If the answer is "no," then perhaps
a form of standby power generation should be cc idered.

The following six conditions must be analyzed to deter-
mine the need for and size of standby power generation.

1. Frequency of power outages in last 10 to 15 years.

2. Duration of the power outage ir. each occurrence.

3. Availability of additional source of power supply from a
different substation in the vicinity.

4. Method by which raw water reaches plant (is flow by
gravity or by a raw water pumping station*?).

5. Total storage capacity of reservoirs in the distribution
system.

6. Possibility of obtaining a potable water supply from
adjacent cities (is there a reasonably sized pipe connec-
tion between your system and the distribution system of
an adjacent city?).

If the frequency of power outages is once or twice a year
with a 10 to 30 minute duration, the capacity of a standby
power generator can be relatively small. The minimum size
of a standby power generator may require sufficient capac-
ity to operator essential equipment such as:

1. Coagulant and chlorine feeders,

2. One-third of flocculators,

3. Major electric valve operators and plant control system,

4. One-third of pumping capacity (if necessary), and

5. Minimum lighting.

er|c

Where do you begin? You have to consider whether you
would like to have all of your facility operating or whether
just the vital or key equipment would be sufficient. Since the
characteristics and operating conditions of every p.ant are
different, it is extremely difficult to make specific sugges-
tions.

For the sake of illustration, let us pose a hypothetical
situation. Consider a 10 MGD (38 MLD) capacity plant with
an average flow rate of 6 MGD (23 MLD). Prepare a list of
needs that must be met to insure minimal operation:

1. Raw water pumping,

2. Clanfication,

3. Clear water pumping,

4. Chlorination, and

5. Minimal lighting.

Calculate the maximum horsepower or total kilowatts
necessary to maintain the limited operation:

1. Raw Water Pump — 75 horsepower

2. Clanfication — 2V2 horsepower

3. Clear Water Pump 40 horsepower
4 Chlonnation — 15 horcepower
5. Lighting

56.00 kW
2.24 kW
30.00 kW
11.20 kW
5.00 kW
104.44 kW

The minimum power required is 104.44 kW. When sizing a
generator for emergency power, you have to make sure that
the operator will be able to start the needed motors. Since
the locked rotor current of the 75 horsepower induction
motor on the raw water pump is approximately four times
running current, then the generator must be able to handle
224 kW at that instant. Size the generator not only by total
load, but also for the highest horsepower motor being
started. Consider the sequence in which motors will be
started. The starting of all the motors simultaneously (with-
out sequence starting) wculd be nearly impossible. Consult
experts in power generation for answers to your specific
questions regarding your plant because each plant has
different needs If you are considering standby power, shop
around and get ideas from the equipment manufacturers.
You may be able to reduce the size of the generator by using
reduced voltage starters on the larger motors.

After you have determined the size or generator needed,
you must^be able to connect it to ycjr power distribution
system. This may require some sophisticated switch gear.
Besides the mechanical functions necessary in connecting
the emergency power with your normal system, it is impor-
tant that the two systems cannot be electrically coupled.
(Two electrical systems must be "in phase" v/ith each other

264

Maintenance 245

before parallel coupling.) For this reason, mechanical inter-
locks are used to insure that one circuit is always open. A
"kirk-key" system, where one key is used for two locks,
locking one sw'tch open before the other can be closed, is
sometimes used. The manufacturers of most packaged
motor-generator systems can provide automatic transfer
switches that will automatically start the generator when a
power failure occurs and connect the generated power into
the plant power aistribution wiring.

Looking back at the plant described, a generator of 125
kW with intermittent overload capabilities should handle the
load. (Note: This is an assumption. Actual calculation may
indicate a different size.) An engine-generation system of
this size could handle your minimal power needs. If your
water distribution system has ample capacity, it may be
possible to cut the plant production rate to reduce power
requirements to what can be handled with a smaller capacity
generator.

If you do not have standby power generation at your
facility, talk to others in the water treatment field who do and
obtain ideas and information. After due consideration, take
the necessary steps to insure yourself against interrupted
power.

Standby power generators should be operated on a
regular basis (once a week) to be sure they wih operate
properly when needed. Be sure to operate your generator at
full load for at least an hour. Commercial power into your
plant must be shut off to operate standby power at full load.

18. 152 Emergency Lighting

The most practical form of emergency lighting in most
instances is that provided by battery-powered lighting units.
Because they are used primarily for exit lighting, they are
more economical than engine-driven power sources. If you
have a momentary power outage, the system responds
without an engine-generator start-up. All emergency lighting
unit equipment is basically the same and consists of a
rechargeable battery, a battery charger, low voltage flood
lights, and test monitoring and control accessories. Proper
selection of a unit for a particular location requires careful
consideration of the following itens:

1. Initial cost,

2. Types of batteries,

3. Maintenance requirements, and

4. Lighting requirements.

The three types of batteries most commonly used are:
lead acid, lead calcium, and nickel cadmium Because poor
battery maintenance is quite common in emergency lighting
systems, "maintenance free" batteries are becoming in-
creasingly popular. These batteries can have a gelatin or
acid (wet) ELECTROLYTES The gelatin type is completely
spillproof and can be handled safely without the dangers of
acid spills. These batteries have a shorter life span than the
wet type. Since all batteries undergo evaporation, the gelatin
electrolyte wui be exhausted before that of a battery contain-
ing liquid. Wet-lype maintenance free batteries require no
refilling and, when handled properly, acid spillage Is minimal.

In terms of cost, the maintenance-free battery is more
expensive: but when you consider the human factor, they
may be more reliable and cheaper in the long run. Most
systems use a battery charger that monitors the battery
voltage. When required, the charger then charges the batter-

ies. In earlier designed units, a trickle charger was used
This constant charging resulted in inoperative batteries in a
short time because of overcharging

The lamps used are normally 6 to 12 volt sealed-beam 25-
watt lamps The light pattern provided is most effective when
Illuminating a work area. A rule of thumb is that one lamp will
be sufficient for about 1.000 square feet, providing that the
full light pattern can be used. Consult emergency light level
codes (Table 18.2) for your particular application.

W'len selecting an emergency lighting system, check it
very thoroughly to insure that it will give you the protection
needed. If it fails to work ./hen the chips are down and the
mar oower is out, you've wasted your money.

18.153 Batteries

This section will discuss wet storage batteries since they
are the most prevalent. Automotive and equipment batteries
are usually of the lead-acid type. This indicates that the
dissimilar plates are made of two types of lead and the
electrolyte is sulfuric acid. Wet-type batteries can also be
mckel cadmium or nickel iron.

Most batteries are a series of cells enclosed in a common
case. Each of these cells develops a potential (voltage) of
2 3 volts per cell when fully charged. Hence, a six-volt
battery contains three cells and a 12-volt battery has six
cells. The voltage output of a 12-volt battery is 13.8 volts
when fully charged. Once a lead-acid battery has been
placed in service, the addition of sulfuric acid is not neces-
sary. The water portion of the electrolyte solution evapo-
rates as the battery is charged and discharged. Lost watDr
must be replaced. Deionized or distilled water should be
used. Tap water contains impurities that shorten the life
span of a battery if used to replace lost water. These minute
particles become attached to the lead plates and co not
allow the battery to rejuvena. self fully when charged.

When batteries are placed on charge, remove the cell
covers to allow the gas (hydrogen) caused by charging to
escape and not to build excessive pressure in the battery. A
battery on charge is as lethal as a small bomb if you ignite
the gas. Do not smoke or cause electrical arcing near the
battery. Do not breath the gas and make sure that the area
where a battery is being charged is well ventilated.

The keys to prolonged life of a battery are to '<eep the
electrolyte level above the cell plates, to keep the battery
fully charged, and above all, to keep the terminals and top
clean. When dirt and residue accumulate on the top of a
battery, it forms a path for current to flow between the
negative and positive posts. Take a multimeter, connect cne
lead to the proper post (it will cause up-scale deflection) and
s'owly slide the other lead across the top of the battery
toward the other post. If the top is dirty, the meter will deflect
mc? as you proceed across the top.

ti Electrolyte (ee-LECK-tro-LlGHT), A substance which dissociates (separztes) into two or more ions when it is dissolve ' in water

ERIC

246 Water Treatment

Hazard requiring visual
detection

NORMAL
ACTIVITY
LEVEL*

Areas

TABLE 18.2 lES RECOMMENDED EMERGENCY LIGHT LEVELS^

Slight High

LOW

Conference rooms
Reception rooms
Exterior floodlighting
Closets

Footcandles
Dekalux

0.5
0.54

HIGH

Lobbies

Corridors

Concourse

Restrooms, washrooms
Telephone switchboard

rooms
Exterior entrance
Exterior floodlighting

1.0
1.1

LOW

Elevators (freight)
File rooms
Mail rooms
Offices
Stairways
Stockrooms
Exterior entrance with
stairs

2.0

2.2

HIGH

Elevators
Escalators
Computer rooms
Drafting rooms
Offices
Stairways
Transformer vaults
Engine rooms
Electrical, mechanical,
plumbing rooms

5.0

2.2

Minimum illumination for safety of personnel, absolute minimum at any time and at any location on any plane where safety is related to
seeing conditions. '

• Special conditions may require different levels of illumination. In some cases higher levels may be required as for example where securi-
ty IS a factor In some other cases greatly reduced levels of illumination, including total darkness, may be necessary specifically in situa-
tions involving manufacturing, handling, use. or processing of light-sensitive materials (notably in connection with photographic
products). In these situations alternate methods of insuring safe operation must be relied upon.
EMERGENCY LIGHT LEVEL codes and standards vary widely throughout the country Recommended minimurr lighting levels of the Illu-
minating engineering Society are being considered as a possible standard by ANSI and the Life Safety Code. These are minimum liqhtinq
levels recommended for safety of personnel.

To Clean the battery, use a stiff-bristled brush (not a wire
brush) and remove the heavy material. Then wash with a
solution of baking soda and water (four teaspoons of baking
soda to one quart of water). This will remove the acid film
from the top and neutralize corrosion on the battery termi-
nals. Rmse with fresh water and dry the top with a dry,
lintless cloth. Remove cell caps and wipe between them,
then replace. At this time check to be sure that the battery
terminals are clean and tight. If a battery is charged, but the
terminals are loose, proper voltage and current cannot be
delivered.

QUESTIONS

Write your answers in a notebook and then compare your
answers with t/,ose on page 32^».

18 15A Why should a qualified electrician perform most of
the necessary maintenance and repair of electrical
equipment?

18.15B What is the purpose of a "kirk-key" system?

18 15C Why are battery-powered lighting units considered
better than engine-driven power sources?

18.15D Why should the water lost from a lead-acid battery
be replaced with deionized or distilled water?

18.16 High Voltage

18.160 Transmls^f'cn

In general terrr'j, high voltage is the voltage transmitted to
the plant site by the utility company. The voltage level can
vary, but 12,000 volts is quite common. After the power

Er|c

reaches *i b plant, it is transformed down to a useable
voltage ( .0 to 480 volts) either through utility-owned or
customer-owned transformers. The NEC (National Electrical
Code) denotes high voltages as those over 600 volts.

Why have high voltage? Since current (amperes) vanes
inversely with voltage, a load of 500 amps on the low voltage
side of the transformer would create a 20 amp load on the
high voltage side of a 12,000 volts/480 volt transformer.
Transmission lines would have to be enormous in order to
carry the load if a lower voltage were used. Where high
voltage cables terminate at a transformer or switch gear,
certain conditions must be adhered to. If outdoor transform-
ers are used that have high voltage wires exposed, an eight-
foot (2.4 m) high fence is required to prevent accessibility by
unqualified or unauthorized persons. Signs attached to the
fence must indicate "High Voltage." Specifications for clear-
ances, grounding, access, and enclosures vary with installa-
tions. Any modification or repair work must be completed by
qualified people oniy.

18.161 Switch Gear

When we see the term "switch gear," it is usually associat-
ed with the equipment used in the interruption, transfer, or
disconnecting of voltages over 600 ^/oWs. The enclosure is
designed and manufactured to safely control high-voltage
switching. Most distribution systems have a load-interrupt-
ing switch that is capable of disconnecting high voltage lines
that are unde, load. Because of the arc that is caused in
breaking the circuit, special "arc shoes'* (arc-suppressant
devices) are used to ensure that the contact points are not
p tted. A keyed lock system is used to prevent opening of the
enclosure in the eneigized state.

26'6

Maintenance 247

Probably the best preventive maimenance that a treat-
ment plant operator can provide for switch gear is to keep
the exterior and its surroundings clean if you encounter
difficulties in the course of operating the switches, please
obtain qualified help to do the inspection or lepairs needed
Check with your particular manufacturer to determine what
IS needed and when this has to be done to keep your system
functioning as designed. If your equipmeiit is in a corrosive
atmosphere, it may be necessary to remove it from service
and expoxy paint the internal buses. All pivoting points
should be lubricated with a lubricant specified by the manu-
facturer.

18. 162 Power Distribution Transformers

If the high voltaje transformers are owned by the utility,
the inspection and maintenance is earned out by the utility.
Any peculiar changes, smells, or noises should be reported
to the utility. When transformers are customer owned, a
regular inspection program should be established.

Most transformers use an oil to insulate as well as to cool
the windings. As heat is generated in the windings, it is
transferred to the oil. The oil is then cooled by air passing the
cooling fins of the transformer. The prinnary requirements
of the oil are:

1. High dielectric strength;

2. Freedom from inorganic acid, alkali, and sulfur to prevent
injury to insulation and conductors;

3. Low viscosity to provide good heat transfer: and

4. Freedom from sludging under normal operation condi-
tions.

The principal causes of deterioratio.. of insulating oil are
water and oxidation. The oil may be exposed to moisture
through condensation of moist air due to "breathing" of the
transformer, especially v^hen the transformer is not continu-
ously in service. The moist air condenses on the surface of
the oil and on the inside of the tank. Oxidation causes
sludging. The amount of sludge formed in a given oil
depends upon the temperature and the time of exposure of
the oil to the air. Excessive operating temperatures may
cause sludging of any transformer oil. Check with the
manufacturer to determine how often the oil should oe
tested. Oil can be revitalized by a cleaning procedure that is
accomplished at the transformer site.

Any symptoms such as unusual noises, high or low oil
levelc. oil leaks, or high operating temperatures should be
investigated at once. If your transformer has a thermometer.
It IS of the alcohol type and should be replaced with that type
only. A mercury-type thermometer could cause insulation
failures by reason of proximity of a metallic substance,
regardless of whether it is intact or broken.

The tank of every power transformer should be grounded
to eliminate the possibility of obtaining static shocks from it
or from being injured by accidental grounding of the winding
to the case.

If repairs are indicated, u3e the expertise of a qualified
person to ensure that the repairs are made safely as well as
correctly. Your life and the lives of others may depend on the
use of qualifiea people.

QUESTIONS

Write your answers in a notebook and then cortipare your
answers with those on page 324.

ERIC

18 ISA Why IS electricity transmitted at h'gh voltage''

18 16B What precautions must be taken if outdoor trans-
formers have exposed high voltage wires''

16 i6C 'vVhdl Kind of rnainlenance should a treatment plant
operator perform on switch gear''

18 16D What symptoms indicate that a power distribution
transformer may be m need of maintenance or
repair''

18.17 Electrical Safety Check List

Throughout this manual and throughout this cnapter the
need for electrical safety is always being stressed. This
section contains an electncal safety check list which is
provided to help you ensure that you have minimized electri-
cal hazards m your plant. This list is piovided to make you
asr.are of potential electrical hazards. You should add to the
list additional electrical hazards that could in|ure someone at
your water treatment plant.

1 Are there any conduits rusted to the point where they
might have lost their explosion proof integrity''

2. Are there any elect-ical conduit hangers that are rusted
so bad that they are allowing the conduit to sag?

3 Are there any fasteners on the conduit hangers that are
rusted and allowing the conduit to hang by the wires?

4 Do all of the extension cords and power tools meet code
requirements for use in wet areas?

5. Does the age.'icy or utility have a policy covering the
proper placement of portable ventilation equipment whcr^
operators work inside enclosed tanks, vaults and other
confined spaces''

6. Does the agency use proper grounding units (ground
fault interruptor3) when working in wet areas?

7. Is the g-ounding of electrical equipment and systems
inspected regularly?

8 Are electrical breakers and controls clearly marked''

9 Is there a formal program for lock.ng out, tagging and
blockout of electncal devices?

If you can answer these questions properly, you are
working in the nght Oirection to minimize electrical hazards
in your water treatment plant.

QUESTIONS

Write your answers m a notebook and then compc 'e your
answers v^rith those on page 324.

18.17A Why are rusted conduits of concern to a water
treatment plant operator''

18.17B What is the purpose of an electrical safety check
'•sf

18.18 Additional Reading.

1. BASIC ELECTRICITY by Van Valkenburgn, Nooger &
Neville. Inc. Obtain from The Brolet Press, 33 Gold Street,
New York. N.Y. 10038. $39.95 for combined Edition of all
five volumes.

a. Volume 1. Price $10.50.
Where Electricity Comes From
Electncity in Action
Current Flow, Voltage, Resistance
f^agnetism. DC [Meters

248 Water Treatment

b. Volume 2. Price $10.50
Direct Current

Ohm's and Kirchoff s Law
Electric Power

c. Volume 3. Price $10.50.
Alternating Current

Resistance. Inductance. Capacitance m AC

Reactance

AC Meters

d. Volume 4. Price $10.60.
Impedance.

Alternating Current Circuits
Series and Parallel Resonance
Transformers

e. Volume 5. Price $10.50.
DC Generators and Motors
Alternators and AC Motors
Power Control Devices

NOTE' For an additional S2 00 per volume, you can
obtain an "interactive Self-Learning Package.'

f Other Training Programs
Bas«c Electronics. 6 Volumes
Basic Industrial Electricity. 2 Volumes

2 "Maintenance" by Stan Wuiton. Volume II. Chapter 15 in
OPERATION OF WASTEWATER TREATMENT PLANTS,
Kenneth D. Kern. California State University. Sacramen-
to. 6000 J Street. Sacramento. CA 95819. Price for
Volume II. $25.00.

3. "Instrumentation" by George Ghara, Chapter 8, in AD-
VANCED WASTE TREATMENT Kenneth D. KerrI, Cali-
fornia State University, Sacramento. 6000 J Street, Sac-
ramento, CA 95819. Price, $20.00.

4 ELECTRICITY PRINCIPLES AND PRACTICES by Ad-
ams. McGraw-Hill Book Company 817^ Redwood High-
way Novato. CA 94547 Price S24.95.

5. "Electrical and Automation," Chapter XII in WATER DIS-
TRIBUTION OPERATOR TRAINING HANDBOOK, by LE.
Nichols and B.W. Jex. Obtain from American Water
Works Association, 6666 W. Quincy Ave., Denver, Colo-
rado 80235. Order No. 20103. Price $14.50 for members
of AWWA, $17.50 for others.

6. MAINTENANCE ENGINEERING HANDBOOK by Higglns,
McGraw-Hill Book Company, PO Box 402, Highstown,
New Jersey 08520. Price $79.50.

7. ELECTRICITY FOR WATER AND WASTEWATER
TREATMENT PLANT OPERATORS. Available from Na-
tional Environmental Training Association, 8687 Via de
Ventura, Suite 214, Scottsdale, AZ 85258. Price $181.50.

8. MECHANICAL MAINTENANCE FOR WATER AND
WASTEWATER TREATMENT PLANT OPERATORS.
Available from National Environmental Training Associ-
ation, 8687 Via de Ventura, Suite 214, Scottsdale, AZ
85?58. Price $156.50.

6 fid c( IC^OK 1 5 Ic^^

MAINTCNANJe

Please answer the discussion and rt view questions be-
fore continuing with Lesson 2.

DISCUSSION AND REVIhW QUESTIONS

ChaptenS. MAINTENANCE

(Lesson 1 of 5 Lessons)

At the end of each lesson in this chapter you will find some
discussion and review questions that you should work
before continuing. The purpose of these questions is to
indicate to you how well you understand the material in the
lesson.

Write the answers to these questir ' in your notebook.

1 Why should operators thoroughly »cad and understand
manufacturers' literature before attempting to maintain
plant equipmenf^

2 Why must administrators or supervisors be made aware
of the need for an adequate maintenance program'^

3. What IS the purpose of a maintenance recordkeeping
program?

4. What Items should be included in a plant library'?

5- Why should your plant have an emergency team to
repair chlorine leaks'?

B Why should one person never be permitted to repair a
chlorine leak alone'?

7 Why should inexperienced, unqualified or unauthorized
persons and even qualified and authorized persons be
extremely careful around electrical panels, circuits, wir-
ing and equipmenf?

8 What protective or safety devices are used to protect
operators and equipment from bemq harmed by elec-
tric y'?

9 Why must motor name pi.-'te data be recorded and filed?

10 What might be the cause ot a pump motor failing to
start?

11 Why should a water treatment plant have standby
power'?

12 How would you deterrnme the capacity of standby
generation equipmenf?

Maintenance 249

CHAPTER 18. MAINTENANCE

(Lesson 2 of 5 Lessons)

18.2 MECHANICAL EQUIPMENT

Mechan-cal equipment commonly lised in water treatment
plants is describa; and d 3c jssea in this section. Equipment
used with specific treatme'il processes such as flocculation
and filtration is not discussed. You must be familiar with
equipment and understand what it is intended to do before
developing a preventive maintenance program and main-
taining equipment.

18.20 Repair Shop

Many large plants have fully equipped mach;ne shops
staffed with competent mechanics. But for smaller plants,
adequate macnine shop facilities often can be found in the
community. In addition, most pump manufacturers maintain
pump repair departments where pumps can be fully recondi-
tioned.

The pump repair shop ir a large plant commonly includes
such items as welding equipment, lathes, drill press and
drills, power hacksaw, flame-cutting equipment, microme-
ters, calipers, garss, portable electric tools, grinders, a
forcing press, metal-spray equipment, and sand-blasting
equipment, ^'ou must determine what repair work you can
anf^ should do and when you need to request assistance
from an expert.

Some agencies have their own repair shops or local
machine shops rebuild parts rather than buying direct from
manufacturers. Many agencies try to select equipment on
the basis the reputations of distributors for supplying
repair parts when needed. A parts inventory is essential for
key pieces c .quipment.

18.21 Pumps

Pumps serve many purposes in water treatment plants.
They may be classified by the character of tht material
handled, such as raw or filtered v^ater. Or, they may relate to
the conditions of pumping: high lift, low lift, or high capacity.
They may be further classified by principle of operation,
such as centrifugal, propeller, reciprocating, and turbine
(Figure 18.14).

The type of material to be handled and the function or
required performance of the pump vary so widely that the
designing engineer must use great care in preparing specif»-
cations for the pump and its controls. Similarly, the operator
must conduct a maintenance and management program
adapted to the peculiar characteristics of the equipment.

18.210 Centrifuga! Pumps

A centrifugal pump is basically a very simple device; an
impf-'ier rotating in a casing. The impeller is supported on a
shaft which is, in turn, supported by bearings. Liquid coming
in at the center (eye of the impeller (Fipure 18.15)) is picked
up by the vanes and by the rotation of tne impeller and then
is thrown out by centrifugal force nto the discharge.

To help you understand how pumps work and the purpose
of the various parts, a section titled "Let's Build a Pump" has
been included the followinq pages. This material has
been repririied with \he permission of Allis-Chalmers Corpo-

ration, Milwaukee, Wisconsin, Industrial Pump Division, Nor-
wood. Ohio. Originally, the material was printed in Allis-
Chalmers Bullei. 08X62568.

18.211 Let's Build a Pump!

A student of medicine spends long years learning exactly
how the human body is built before attempting to prescribe
for Its care. Knowledge of PL^/WP anatomy is equally basic in
caring for centrifugal pumps!

But whereas the medical student must take a body apart
to learn its secrets, it will be far more instructive to us if we
put a pump TOGETHER (on paper, of course). Then we can
start at the beginning — adding each new part as we need it
in logical sequence.

As we see WHAT each part does, HOlVit does it . . . we'll
see how it must be CARED FOR!

Another analogy between medicine and maintenance:
there are various types of human bodies, but if you know
basic anatomy, you understand them all. The same is true of
centrifugal pumps. In building one oasic type, we'll learn
about ALL types.

Part of this will be elementary to some maintenance
people ... but they will find it a valuable "refresher" course,
and, after all, maintenance just can't be too good.

So, with a glance at the centrifugal principle on page 252,
let's get on with building our pump . . .

FIRST WE REQUIRE A DEVICE TO SPIN LIQUID AT HIGH
SPEED . . .

That paddle-wheel device is called the "impeller" . . . and
It's the heart of our pump.

Note that the blades curve out from its hub. As the impeller
spins, liquid between the blades is impelled outward by
centrifugal force.

2IJ3

PUMPS

PUWPS

DYNAMIC

— 'OlSPLACEMFNT

CENTRIFUGAL

— AXIAL FLOW

SINGLE STAGE -IT CLOSED IMPELLER

H pFlXCD PITCH

J u - -» '

MULTISTAGE

•OPEN IMPELLErH

-VARIABLE PITCH

MIXED FLOW.
RADIAL FLOW

SINGLE
SUCTION

. 00'J8LE
SUCTiON

f- SELF -PRIMING -i
NONPRIMING —
SINGLE STAGE
MULTISTAGE — '

OPEN
IMPELLER

, SEMI-OPEN
IMPELLER

CLOStD
IMPELLER

PERIPHE.'JAL

p Single staget tSElf-priming

MULTISTAGE

SPECIAL EFFECT

NONPRIMING

JET (EDUCTOR)

- GAS LIFT

- HYDRAULIC RAM

- ELF.CTROMAGNETIC

Dynamic types of pumps

r DISPLACEMENT

DYNAMIC j

- RECIPROCATING

2V"

PISTON.
PLUNGER

r- STEAM -DOUBLE ACTING

SIMPLEX
DUPLEX

POWER

SINGLE ACTING -i
DOUBLE ACTING J~

- SIMPLEX

I- DUPLEX
- TRIPLEX
^ MULTIPLEX

DIAPHRAGM

|— SIMPLEX -I -
1- MULTIPLEX -i L

- FLUID OPERATED

MECHANICALLY OPERATED

ROTARY

SINGLE ROTOR

- VANE

- PISTON

Flexible member

MUL'^IPLE ROTOR

- SCREW

- PERISTALTIC
p GEAR

- LOBE

- CIRCUMFERENTIAL PISTON

- SCREW

Displacement types of pumps

Fig. 18, 14 Classification of pumps

Maintenance 251

Refer to Fig. 18.18, pages 258 and 259, for location of impeller in pump

Fig. 18. 15 Diagram showing details of centrifugal pump impeller

(Source CENTRIFUGAL PUMPS by Karasstk and Curter of Worthtngton Corporation)

Note, too, that our impeller is open at the center — the
••eye." As liquid in the impeller moves outward, it will suck
more liquid in behind it through this eye . . . PROVIDED IT'^^
NOT CLOGGED!

That brings up Maintenance Rule No. 1; if there's any
danger that foreign matter (sticks, refuse, etc.) may be
sucked into the pump — clogging or wearing the impeller
unduly — PROVIDE THE INTAKE END OF THE SUCTION
PIPING WITH A SUITABLE SCREEN.

NOW WE NEED A SHAFT TO SUPPORT AND TURN THE
IMPELLER . . .

Our shaft looks heavy — and it IS. It must maintain the
impeller in precisely the right place.

But that ruggedness does A/07 protect the shaft from the
corrosive or abrasive effects of the liquid pumped ... so we
must protect it with sleeves slid on from either end.

ERLC

271

Water Treatment

ALL AA0VIN6 BOOiCS TEHOTOTRAVeLINASrRAHHT
UNE.WHCN FORCED TO TRAVEL IN ACURVEflHCY
CONSTANTLY TRY TO TRAVEL ON ATANOCNT.^

Otntriiugai force pushes dummy planes smmg'
in a. eirde /rom center cj^iritation..

... /Af^

Centrifugal fsrec tends to putfi swirling wiler
outvMrd.,. forming vorteicin center.

272

Maintenance 253

What these sleeves — and the impeller, too — are made
of depends on the nature of the liquid we're to pump.
Generally they're bronze, but various other alloys, ceramics,
glass, or even rubber-coating are sometimes required.

Maintenance Rule No. 2: NEVER PUMP A LIQUID FOR
WHICH THE PUMP WAS NOT DESIGNED.

Whenever a change in pump application is contemplated
and there's any doubt as to the pump's ability to resist the
different liquid, CHlCK WITH YOUR PUK:P MANUFAC-
TURER!

WE MOUNT THE SHAFT ON SLEEVE, BAuL OR ROLLER
BEARINGS . . .

As we'll see later, clearances between moving parts of our
pump are QUITE SMALL.

If beanngs supporting the turning shaft and impeller are
allowed to wear e^^^^ssively and lower the turning units
within a pump's closely-fitted mechanism, the life and effi-
ciency of that pump will be seriously threatenec

Maintenance Rule No. 3: KEEP THE RIGHT AMOUNT OF
THE RIGHT LUBRICANT IN BEARINGS AT ALL TIMES.
FOLLOW YOUR PUMP MANUFACTURER'S LUBRICATION
INSTRUCTIONS TO THE LETTER.

Mam points to keep in mind are . . .

1. Although too much oil won't harm sleeve bearings, too
much grease in antifriction type bearings (ball or roller)
will PROMOTE friction and heat. Main job of grease in
antifriction bearings is to protect steel elements against
corrosion, not friction.

2. Operating conditions vary so widely that no one rule as to
frequency of changing lubricant will fit all pumps. So play
safe: if anything, change lubricant BEFORE \Vs too worn
or too dirty.

TO CONNECT WITH THE MOTOR, WE ADD A COUPLING
FLANGE . . .

Some pumps are built with pump and motor on one shaft,
of course, and offer no alignment problem.

But our pump is to be driven by a separate motor . . . and
we attach a flange to one end of the shaft through which
bolts will connect with the motor flange.

ERIC

Maintenance Rule No. 4: SEE THAT PUMP AND MOTOR
FLANGES ARE PARALLEL VERTICALLY AND AXIALLY . . .
AND THAT THEY'RE KEPT THAT WAY'

If shafts are eccentnc or meet at an angle, every revolution
throws tremendous extra load on bearings of both pump and
motor. Flexible couplings will A/Or correct this condition if
excessive.

Checking alignment should be regular procedure In pump
maintenance. Foundations can settle unevenly, piping can
change pump position, bolts can loosen. Misalignment is a
MAJOR cause of pump and coupling wear.

NOW WE NEED A "STRAW" THROUGH WHICH LIQUID
CAN BE SUCKED . . .

Notice two things about the suction piping: 1) the horizon-
tal piping slopes UPWARD {ov^ar6 the pump; 2) any reducer
which connects between the pipe and pump intake nozzle
should be horizontal at the top — {ECCENTRIC, not concen-
tnc).

AllOWCD Br wOWM SiO'IN&PlT>i Allowed By TAPCT^DBrCUCI'R

273

254 Water Treati?ent

This up-sloping prevents air poc»<eting in the top or the
pipe which air might be d awn into the p'lmp and cause
loss of suction.

Maintenance Rule No. 5: ANY DO\vNSLOPING TOWARD
THE PUMP IN SUCTION PIPING (AS EXAGGERATED IN
THE DIAGRAMS ABOVE) SHOULD BE CORRECTED,

This rule is VERY important. Loss of suction greatly
endangers a pump . . as we'll see shortly.

WE contmIn and direct the spinning liquid with a

CASING . . .

We got a little ahead of our story in the previous para-
graphs . . . because we didn t yet have the casing to which
the suction piping bolts. And the manner in which it is
attached is of great importance.

Maintenance Rule No. 6: SEE THAT PIPING PUTS ABSO-
LUTELY NO STRAIN ON THE PUMP CASING.

T«C WClSMTOF -PlPlNvJ CAN
EASILY T»UIW A PUMP/

When thr original installation is made, all piping should be
in place arid self-supporting before connection. Openings
should m'^et with no force. Otherwise ine casing is apt to be
c ?cked ... or sprung enough to allow closely-fittec oump
Parts to ruL.

It's good practice to check the piping supports regulaHy to
see that loosening, or settling ')f the building, hasn't put
strains on ^he casing.

NOW OUR PUMP IS ALMOST COMPLETE, BUT IT WOULD
LEAK • 'XE A SIEVE . . .

We're far enough along now to trace the flow of water
through our pump. 5'<'s not easy to show suction piping in the
cross-section view above, so im?5qini3 it stretching fr^^m your
Gve to the lower center of the p. np.

ERIC

Our pump happens to be a "double suction" pump, which
means th^*t water flow is divided inside the pump casing . . .
reaching t! ^ eye of the impeller from either side

/liquid socs

•UT50Mf Of IT LEAKS

^AClC<f ROM fRESSURE 10 SUCTION I

As water is sucked into the spinning impeller, centrifugal
force causes it to flow outward . . . building up high pressure
at the outside of the pump (which will force water OUT) and
creating low pressure at the center of the pump (which will
suck water IN.) This situation is diagrammed m the upper
half of the pump, above.

So tar so good . . . except that water ten ' to be sucked
back from pressure to suction through the s\, ice between
impeller and casing — as diagrammed in the lower l-.alf of
the pump, above — and our next step must be to plug this
leak, if our pump is to be very efficient!

SO WE ADD WEARING RINGS TO PLUG INTERNAL LIQUID
LEAKAGE . . .

You might ask why we didn't build our parts closer fitting
m the first place — instead of narrowing the gap between
them by inserting wearing rings.

The answer is that those rings are removable r.nd RE-
PLACEABLE . . . when wear enlarges the tiny gap between
them and the impeller. (Sometimes nngs are attached to
impeller rather than casing — or rings are attached to BOTH
so they face each other.)

^57

A LOT X>EPEhOS on

27i

Maintenance 255

Maintenance Rule No. 7. NEVER ALLOW A PUMP TO
RUN DRY (either through lack of proper priming when
Gtarting or through loss suction when operating). Water is
a LUBRICANT bexv^een rings and impeller.

Maintenance Rule No. 8. EXAMINE WEARING RINGS AT
REGULAR INTERVALS. When seriously worn, their replace-
ment will g»'eatly improve pump efficiency.

TO KEEP AIR FROM BEING SUCKED IN, WE USE STUFF-
ING BOXES . . .

We have two good reasons for wanting to keep air out of
our Dump: 1) we want to pump water, not air; 2) air leakage is
apt to cause our pump to lose suction.

Each stuffing box we use cc.isists of a casing, rings of
packing and a gland at the oUiSide end.

Maintenance Rule No. 9: PACKING SHOULD BE RE-
PLACED PERIODIC ALL Y — DEPENDING ON CONDITIONS
— USING THE PACKING RECOMMENDED BY YOUR
PUMP MANUFACTURER. Forcing in a ring or two of new
packing instead of replacing worn packing is BAD PRAC-
TICE. It's apt to displace the seal cage (see next column).

Put each ring of packing in separately, seating it firmly
jiore adding the next. Stagger adjacent rings so the points
where their ends meet do not coincide.

Maintenance Rule No. 10: NEVER TIGHTEN A GLAND
MORE THAN NECESSARY ... as excessive pressure will
wear shaft sleeves unduly.

Maintenance Rule No. 11: IF SHAFT SLEEVES ARE
BADLY SCORED, REPLACE OR REPAIR THEM IMMEDI-
ATELY ... or packing life will be entirely too short.

TO WAKE PACKING MORE AIR-TIGHT, WE ADD WATER
SEAL PIPING...

In the center of each stuffing box is a "seal cage." By
connecting it with piping to a point near the impeller rim, we
bring liquid UNDER PRESSURE \o th3 stuffing box.

This liquid acts both to block out air intake and to lubricate
the packing. It makes both packing and shaft sleeves wear
longer . . . PROVIDING ITS CLEAN LIQUID'

Maintenance Rule No. 12: IF THE LIQUID BEING
PUMPED CONTAINS GRIT, A SEPARATE SOURCE OF
SrALING LIQUID SHOULD BE OBTAINED (e.g., it may be
possible to direct some of the pumped liquid into a container
and settle the grit out).

To control liquid flow, draw up the gland just tight enough
so a THIN stream flows from the stuffing box during pump
operation.

DISCHARGE PIPING COMPLETES THE PUMP INSTALLA-
TION — AND NOW WE CAN ANALYZE THE VARIOUS
KORCES WE'RE DEALING WITH . . .

)

. ERIC

27 o

256 Water Treatment

SUCTION At least 75% of centrifugal pump troubles trace
to the suction side. To minimize them . .

1 . Total suction lift (distance between center line of pump
and liquid level whr pumping, plus friction losses) gen-
erally should not exceed 15 feet.

2. Piping should be at least a size larger than pump suction
nozzle.

3. Friction in piping should be minimized . . use as few and
as easy bends as possible . . . avoid scaled or corroded
pipe.

DISCHARGE lift, plus suction lift, plus friction in the piping
from the point where liquid enters the suction piping to the
end of the discharge piping equals total head.

PUMPS SHOULD BE OPERATED NEAR THEIR RATED
HEADS.

Otherwise, pump is apt to operate under unsatisfactory
and unstable conditions which reduce efficienc*' and operat-
ing life of the unit.

Note the description of "cavitation" below — and direc-
tions for figuring the head your pumps are working against.

PUMP CAPACITY generally is measured in gallons per
minute A new pump is guaranteed to deliver its rating in
capacity and head.

But whether a pump RETAINS its actual capacity depends
to a great extent on its maintenance.

Weanng nngs must be replaced when necessary — to
keep internal leakage losses down.

Friction must be minimized in bearings and stuffing boxes
by proper lubrication . . . and misalignment must not be
allowed to force scraping between closely-fitted pump parts.

POWER of the driving motor, like capacity of the pump,
will not remain at constant level without proper mainte-
nance.. (If you us electric motors, by all means send for
Allis-Chalmers free "Guide to Care of Electric Motors!")

Starting load on mot^^rs can be reduced by throttling or
closing the pump discharge valve (NEVER the suct'on valve!)

. . but the pump must not be operated for lon^ vith the
discharge valve closed. Power then is converted into friction
— overheating the water with serious consequences.

^Ay£ A ^^^^rTiBsPEcrpoP cAViVArtof^i

IF PWMP CATACITT, 8TtCl>,«EAT>, AMD ^UCTIOM 1.1 Fr '
A^EN'r FIGURED PROPERir, CAVITATV N CAR EAT A|/
IMmi^ AWAY ^Jl A tABoHATORY WATCR-
.HAMMCe INDICATES tT'^SER031VE F0RCF».

3 ci.p^i.s

CAVrTY-HATI ft fMKMQ

2 '^•^•ucfi tmtvt

ERIC

276

Maintenance 257

Cavitation is a condition that can cause a drop in pump
efficiency, vibration, noise and rapid damage to the impeller
of a pump. Cavitation occurs due to unusually low pressures
within a pump. These low pressures can develop when
pump inlet pressures drop below the design inlet pressures
or when the pump is operated at flow rates considerably
higher than design flows. When the pressure within the
flowing water drops very low, the water starts to boil and
vapor bubbles form. These bubbles then collapse with great
force which knocks metal particles off the pump impeller.
This same action can and does occur on pressure reducing
valves and partially closed gate and butterfly valves.

18.212 Horizontal Centrifugal Pumps

Horizontal centrifugal pumps, like the one we just con-
structed on paper in the last section, are available in a
number of configurations. The one we built is best descnbed
as a single-stage, horizont^., double-suction, split-case cen-
trifugal pump. The pump is a single-stage pump because it
has only one impeller. Some horizontal pumps have two
impellers that are working in series to create higher heads
than can readily be obtained with only one impeller. Our
paper pump was double suction in that water entered the
impeller from both sides. The advantage of this design Is
that the longitudinal thrust fro.<t the water entenng the
impeller is balanced. This greaiiy reduces the thrust load
that the pump's bearings must carry. The split case designa-
tion indicates that the pump case is made In two halves.
Some centnfugal pumps have a single suction in line with the
shaft. These are oescribed as single stage end sucuon
centrifugal pumps.

18.213 Vertical Centrifugal Pumps {Figures 1 8.16, 1 8.17
and 18.18)

Another common configuration for centnfugal pumps is
t vertical suction cased centrifugal pump. This is an
adaptation of the deep well turbine pump for booster pump
service. They are very flexible in design as the engineers can
specify either single or multi-stage in a wide variety of sizes
and characteristics.

Besides the usual lubrication or the electric motor, the only
routine maintenance required is to adjust and repair, as
needed, the single packing gland.

Adjusting Nut
Drive Key

Vertical Hollow
Shaft Motor

Top Shaft

Deflector Rin^

Packing Gland

Packing

Lantern

Packing Box

Discharge Head

Packing Box Bushing

Dram Line

Top Column Flange

Shaft Couphng

Column Pipe

Bowl Shaft

Discharge Case Cap

Discharge Case Coupling

Discharge Case

Discharge Care Bearing

Impeiicf

Intermediate Bowl
Imoeller Lock Collet
Intermediate Bowl Bearing
Bowl We^r Ring

Suction Case Bearing

Suction Flange

18.214 Reciprocating or Piston Pumps

The word "reciprocating" means moving back and forth,
so a reciprocating pump is one that moves a liquid by a
piston that moves back and forth. A simpla reciprocating
pump IS shown In Figure 18.19. If the piston Is pulled to the
left. Check Valve A will be open and the liquid wi" 3nter the
pump and fill the casing. When the piston reacnes the end of
its travel to the left and is pushed back to the right, Check
Valve A wi'l close. Check Valve B will open, and the liquid will
be forced out the exit line.

A piston pump is a positive-displacement pump. Never
operate it against a closed discharge valve or the pump,
valve, and/or pipe could be darTJ?^ged by excessive pres-
sures. Also, the suction valve should be open when the
pump is started. Otherwise an excessive suction or vacuum
could develop and cause problems.

18.215 Progressive Cavity (Screw-Flow) Pumps

(Figure 18.20)

The progressive cavity pump consists of a screw-shaped
rotor sniiqly enclosed In a non-moving stator or housing
(Figure 18.2 J). The threads of the screw-like rotor (common-
ly manufactured of chromed steel) make contact along the

Fig, 18.16 Vertical centnfugal pump (multistage)

(Permission of Aurora Pump Company)

m m

Fig. 18.17 Vertical centrifugal pump (single sta. i)

(Permission of Aurora F'ump Company)

277

258 Water Treatment

walls of the stator (usually made of synthetic ruhber). me
gaps between the rotor threads are called "cavities/' When
water Is pumped through an inlet valve, it enters the cavity
As the rotor turns, the material is moved along until it leaves
the conveyor (rotor) at the discharge end of the pump. The
size of the cavities along the rotor determines the capacity of
the pump.

All progressive cavity pumps operate on the basic pnnci-
pie descnbed above. To further increase capacity, some
models have a shaped inside surface of the stator (housing)
with a similarly shaped rotor. In addition, some models use a
rotor that moves up and down Inside the stator as well as
turning on its axis (Figure 18.21). This allows a further
increase in the capacity of the pump.

Progressive cavity pumps are recommended for materials
which contain higher concentrations of suspended solids.
They are commonly used to pump sludges. Progressive
cavity pumps should NEVER be operated dry (without liquid
in the cavities), nor should they be run against a closed
discharge valve.

18.216 Chemical Metering Pumps

Many chemical metering pumps are a type of positive
displacement pump Fo. information on chemical metering
pumps, see Chapter 13, Fluoridation, Section 13.30, "Chemi-
cal Feeders;' and Section 18.4, "Chemical Feeders," in this
Chapter.

QUESTIONS

Wnte your answers in a notebook and then compare your
answers with those on page 324.

18.20A List tfit; pieces of equipment and special tools
commonly found in a pump rpoair shop.

18.21 A What is the purpose oi a pump impeller?

18.21B Why should the intake end of suction piping have a
suitable screen?

18.21C Why must suction piping always be up-sloping?

18.21D What IS cavitation?

18.21E What IS an advantage of having a DOUBLE'SUC-
TION pump over a SINGLE'SUCTfON pump?

1. Motor frame

2. Impeller

3. Oil seal

4. Mechanical seal

5. Frame

6. Casing

7. Shaft sleeve

8. Back pull-out

9. Lubrication fittings

10. Shaft

11. Impeller

12. Bearings

13. Shaft sleeve

14. Close coupled motor support

15. Impeller

16. Wearing ring

17. Oil reservoir

18. Rear support foot

Fig. 18.18 Centrifugal pvmp parts

(Permisston of Aurora Pump Company)

278

Maintenance 259

1. Motor frame 7. Shaft sleeve 13. Shaft sleeve

2. Impeller 8. Back pull-out 14. Close coupled motor support

3. Oil seal 9. Lubrication fittings 15. Impeller

4. Mechanical sea' 10. Shaft 16. Wearing ring

5. Frame 11. Impeller 17. Oii reservoir

6. Casing 12. Bearings 18. Rear support foot

Fig. 16. 16 Centrifugal pump parts (contii d)

PISTON

FLOW IN

Fig. 16,19 S.mple reciprocating pump

o>
o

o
3

280

Fig. 18.20 Progressive cavity (screw-llow) pump

(Permisspon o) Moyno Pump Division. Robbins S Meyer, Inc )

2Si

Maintenance 261

Pumping principle

0°

Fig. 18.21 Pumping principle of a progressive cavity pump

(Permission of Atfweiler Pumpi, Inc )

28?.

262 Water Treatment

18.22 Lubrication

18.220 Purpose of Lubrication

Lubrication of equipment is probably one of the most
important phases of a maintenance operator s job. Wrthout
proper lubrication, the tools and equipment used for operat-
ing and maintaining water treatment plants would fail. Prop-
er lubrication of tools and equipment is probably one of the
maintenance operator's easiest jobs, but often is the most
neglected.

The purpose of lubrication is to reduce friction between
two surfaces- luorication also removes heat that is caused
by friction. Solid fr.ction of two dry surfaces in contact is
changed to a fluid friction of a separating layer of liquid or
liquid lubricant. Actually, water is a lubricant, although not a
good lubricant.

18.221 Properties of K ubricants

A good lubricant must have the following properties:

1. Form a slippery coating on contacting surfaces so they
can slide freely past each other, and

2- Exert sufficient pressure to keep the surfaces apart when
running.

Tc be a good lubncant for a particular job. the lubricant
used must have the following qualities:

1 - Thickiiess of the lubricant layer must be sufficient to keep
the roughness of the metal parts from touching.

2. Lubricity (slipperiness) must be sufficient to allow mole-
cules lo slide freely past each other, and

3. Viscosity (resistance to flow) must be sufficient to bu..d
up a Pr<issure necessary to keep the surfaces apart. If
viscosity alone cannot provide enough pressure, an ex-
ternal pressure must be supplied by a pump.

^2 SSU. Staf.dard Saybolt Units.

ERIC

Viscosity in the United States is the number of seconds it
takes 60 cubic centimeters (cc) of an oil to flow through the
standard orifice of a Saybolt Universal Viscometer at 100,
130. or 210 degrees Fahrenheit. A 300 - SSU^^ @ 130 oii
means that it took 300 seconds for 60 cc to flow through a
Saybolt Universal Viscometer at 130 degrees Fahrenheit.
Viscosity decreases with temperature rise because oil be-
comes thinner The specific gravity of an oil is measured by
comparing the weight of oil with an equal volume of water,
both at 60 degrees Fahrenheit.

Some other important information to know about lubri-
cants IS the:-- "Pour Point." "Flash Point," and Tire Point."
"Pour Point" is the temperature at which a lubricant refuses
to run. This is important in low temperature work. "Flash
Point" is the temperature at which oil vaporizes enough to
ignite momentarily when near a flame. A low flash point
means that oil evaporates more readily in service. "Fire
Point'' IS the temperatuie at which oil vaporizes enough to
keep on burning. Oils in service tend to become acid and
may cause corrosion, deposits, sludging and other prob-
lems. This condition may not be visible when you look at the
oil. Therefore, do not extend the time for an oil change
because the oil looks clean.

To detect acid conditions in oils, the neutralization number
of an oil is ijsed. The neutralization number is the weight in
milligrams of potassium hydroxide required to nei 'alize
one gram of oil. This is used by laboratories which te^t the
oil on large engines, turbines, compressors, and other
equipment which have large volume oil reservoirs to deter-
mine when cil changes or additives are needed.

Most lubricants in gei eral use are fluid at room tempera-
ture. Mostly, these are petroleum base, but others are used.
Greases are mixtures of petroleum products with soaps
such as lime, soda, aluminum, and metallic. Metallic soaps,
forms of calcium, sodium, potassium, and lithium, have good
'-etention in bearings and can withstand high temperatures
and pressures. A sodium base grease has sodium as the
soap mixed with the petroleum.

Solid materials such as graphite, finely ground mica, and
yarn are sometimes used as lubricants. Some recently
developed silicon compounds (silicones) work very well
under heavy loads and widely varying temperatures.

Thore are many oil additives on the market today and they
are worth investigating. Oil additives are chemical com-
pounds added to an oil to improve certain chemical or
physical properties such as stability, lubricity and foaming.
They are used to prevent rust or deposits and many other
items that could cause problems.

18.222 Lubrication Schedule

To have proper lubrication you must first set up a lubrica-
tion schedule. This can be a sii.;ple check-off sh'^et or card
system or an elaborate computer system. The first thing to
do IS make a list of everything that needs lubrication down to
the smallest item including chains, rollers, and sprockets.
After you have listed every item on paper, go through the
manufacturer's instruction books to determine the frequen-
cy and type of lubrication required. Is the frequency daily,
weekly, monthly, semi-annual, or annually? The manufactur-
er's literature usually lists several different name brands of
lubricants which are equal. If you need help determining the
type of lubricant or cross-referencing it to your particular
brand, contact your supplier. Most oil distributors have a
service representative who will come to your facility and go
over the individual equipment and specify which lubricants

283

Maintenance 263

you should use. Next, determine the amount of each lubri-
cant required. This is achieved by counting the number of
grease fittings Determine the locations of fill plugs, dram
piMgs, oil levels, sight glasses, dip sticks and other important
items. To find these locations, physically inspect each piece
of equipment thoroughly and look for all lubrication points.
Also the manufacturer's maintenance manual should shov^^
the lubrication points for each piece of equipm-int.

When you have gathered all this information, transfer it to
the equipment history cards for future reference. From this
information you can make up a lubrication chart or form.

As stated earlier, use whatever type of lubrication form
you prepare, but follow it. Always record each lubrication job
when completed and have the operator who did the job initial
the record card. Always keep your lubrication schedules up
to date. If there are failures due to the wrong or insufficient
lubricant, change or increase the lubrication frequency on
the schedule. Also, new equipment must be added and
discarded equipment removed fnm the schedule. Someone
must be assigned to take care of the lubrication and records.
Assign more than one operator or rotate this job so if an
individual is off work or leaves the crew, there is a continuity
in tha lubrication schedule.

18,223 Precautions

When handling or storing oils and greases, some special
precautions must be followed. Make sure the storage area
does not create a fire hazard. Most all lubricants are highly
flammable and shouldn't be stored wh?re there is an open
flame. "NO SMOKING" signs must be posted outside the
building. Be sure to Keep any spills wiped up and make sure
that all the lids are tight on their containers.

Keep materials and containers clean. Sand, grit, and other
substances can contaminate lube supplies and create an
equipment failure that lubrication maintenance is intended to
prevent. Another good idea is to direct the first shot of
grease from a gun into a waste can.

18.224 Pump Lubrication

Pumps, motors, and drives should be oiled and greased in
strict accordance with the recommendations of the manu
facturer. Cheap lubricants may often be the most expensive
in the end. Oil should not be put in the housing while the
pump shaft is rotating because the rotary action of the ball

ERIC

bearings ptck up and retain a considerable amount of oil
When the unit comes to rest, an overflow of oil around the
shaft or out of the oil cup will result.

Greased bearings should be lubricated as follows:

1. Shut off the unit if moving parts that might be a safety
hazard are close to the grease fitting oi orain plugs.

2. Remove the dram plug from the bearing housing.

3 Remove the grease fitting protective cap and wipe off the
grease fitting. Be sure that you do not force dirt into the
bearing housing along with the clean grease.

4 Pump in clean grease until the g^'case coming out of the
dram hole is clean. Don't pump grease into a bearing with
the dram plug in place. This could easily build up enough
pressure to blow out the seals.

5. Put the protective cap back on the grease fitting.

6. With the dram plug still removed, put the unit back in
service. As the bearing warms up, excess grease will be
expelled from the dram hole. After the unit has been
running for a few hours, the dram plug may be put back m
place. Special drain plugs with spring loaded check
valves are recommended because they will protect
against further buildup.

7 Unless you intend to be very careful, we recommend that
bearing grease be p ^chased in cartridge form to mini-
mize the chance of geumg dirt into the lubricant.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 324.

18.22A What is the purpose of lubrication?

18.22B What happens to oils in service'^

18.220 What should be done to insure prope^ lubrication of
equipment?

18.225 Equipment Lubrication

Different authorities may make conflicting lube recom-
mendations for essentially the same item; however, general
reference material is available to help select the correct
lubricant for a specific application.

Grease is graded on a number scale, or viscosity index, by
the National Lubricating Grease Institute. For example. No. 0
IS very soft.; No. 6 is quite stiff. A typical grease for most
treatment plant applications might be a 2 lithium or
sodium compound grease, which is used for operating
temperatures up to 250°F (120°C).

Generally, the time between flushing and repacking for
greased bearings should be divided by 2 for every 25°F
(15°C) above 150*^ (65°C) operating temperature. Also,
generally, the time between lubrications should not be
allowed to exceed 48 months, since lube component sepa-
ration and oxidation can become significant after this period
of time, regardless of amount of use.

Another point worth noting is that grease is normally not
suitable for moving elements w'th speeds exceeding 12 000
in./min (5 m/s). Usually, oil-lubricating systems are used for
higher speeds. Lighter viscosity oils are recommended for
high speeds, and, within the same speed and temperature
range, a roller bearing will normally require one grade
heavier viscosity than a ball bearing.

284

264 Water Treatment

A good rule of thumb is to change and flush oil completely
at the end of 600 hours of operation or 3 months, whichever
occurs first. More specific procedures for flushing and
changing lubricants are outlined by most equipment manu-
facturers.

Every operator should be aware of the dangers of overfill-
ing with either grease or oil. Overfilling can result in high
pressures and temperatures, and ruined seals or other
components. It has been observed that more antifriction
bearings are ruined by over-greasing than by neglect.

A thermometer can tell a great deal about the condition of
a bearing. Ball bearings are generally in trouble above ISO^'F
(80*^0). Grease-packed bearings typically run 10 to 50 de-
grees above ambient.

Forclanfier drive units, which are almost always located
outdoors, condensation presents a dangerous problem for
the lubrication system. Most units of current design have a
condensate bailing system to remove water from the gear
housing by displacement. These units should be checked
often for proper operation, particularly during seasons of
wide air temperatu'-e fluctuation.

Pumps incoroorate many types of seals and gaskets
constructed of combinations of elastomers and metals. As

for lubricants, conflicting advice can be obtained A file
containing data on general properties of materials used can
help in the choice of lubricant.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 324.

18 22D Does a soft grease have a high or low viscosity
index as compared with a hard grease?

18.22E Is oil or grease used with higher speeds'?

1 8.22F What problems can result from overfilling with oil or
grease?

OVl

Please answer the discussion and review questions be-
fore continuing with Lesson 3.

DISCUSSION AND REVIEW QUESTIONS

Chapter 18. MAINTENANCE

(Lesson 2 of 5 Lessons)

Write your answers to these questions in your notebook
before continuing The question numbering continues trom
Lesson 1.

13. What is the purpose of a purnp shaft?

14. What is the purpose of pump sleeves'^

15. Why should a pump never be allowed to run dry''

16. How would you develop a lubrication schedule for a
pump?

17. Why is cleanliness important in the storing and use of
lubricants?

ERLC

28r,

Maintenance 265

CHAPTER 18. MAINTENANCE

(Lesson 3 of 5 Lessons)

18.23 Pump Maintenance

16.230 Section Format

The format of this section differs from the other chapters.
This format was designed specifically to assist you in
planning an effective preventive maintenance program. The
paragraphs are numbered for easy reference when ycu use
the Equipment Service Cards and Service Record Cards
mentioned in Section 18.00, page 219, and shown in Figure
18.1.

An entire book could be w 'tten on the topics covered in
this section. Step-by-step -tails for maintaining equipment
are not provided because manufacturers are continually
improving their products and these details could soon be out
of date. You are assumed to have some familiarity with the
equipment being discussed. FOR DETAILS CONCERNING
A PARTICULAR PIECE OF EQUIPMENT, YOU SHOULD
CONTACT THE MANUFACTURER. This section indicates to
you the kinds of maintenance you should include in your
program and how you could schedule your work. Carefully
read the manufacturer's instructions and be sure you clearly
understand the material before attempting to maintain and
repair equipment. If you have any questions or need any
help, do not hesitate to contact the manufacturer or your
local representative.

A glossary is not provided in this section because of the
large number of technical words that require familiarization
with the equipment being discussed. The best way to learn
the meaning of these new words is from manufacturers'
literature or from their representatives. Some new words are
described in the lessons where necessary.

18.231 Preventive Maintenance

The following paragraphs list some general preventive
maintenance services and indicate frequency of perform-
ance. There are many makes and types of equipment and
the wide variation of functions cannot be included; therefore,
you will have to use some judgment as to whether the
services and frequencies will apply to your equipment. If
something goes wrong or breaks in your plant, you may
have to disregard your maintenance schedule and fix the
problem now.

NOTE: If you need to shut a unit down, make sure it is also
locked out and tagged properly. (Figure 18.22)

cope-

Paragraph 1: Pumps, General

This paragraph lists some general preventive mainte-
nance services and indicates frequency of performance.
Typical centrifugal pump sections are shown in Figure 18.18.

Frequency
of
Service

D 1. CHECK WATER-SEAL PACKING GLANDS
FOR LEAKAGE. See that the packing box is
protected with a clear-water supply from an
outside source, make sure that water seal
pressure is at least 5 psi (35 kPa or 0.35 kg/
sq cm) greater than maximum pump suction
pressure. See that there are no CROSS-
CONNECTIONS.^^ Check packing glands
for leakage during operation. Allow a slight
seal leakage when pumps are running to
keep packing cool and in good condition.
The proper amount of leakage depends on
equipment and operating conditions. Sixty
drops of water per minute is a good rule-of-
thumb. If excessive leakage is found, HAND
TIGHTEN glands* nuts evenly, but not too
tight. After adjusting packing glands, be
sure shaft turns freely by hand. If serious
leakage continues, renew packing, shaft, or
shaft sleeve.

D 2. CHECK GREASE-SEALED PACKING
GLANDS. When grease is used as a packing
gland seal, maintain constant grease pres-
sure on packing during operation. When a
spring-loaded grease cup is used, keep it
loaded with grease. Force grease through
packing at a rate of about one ounce (30 gm)
per day. When water is used, adjust seal
pressure to 5 p3i (35 kPa or 0.35 kg/sq cm)
above maximum pump suction pressure.
Never allow the seal to run dry.

W 3. OPERATE PUMPS ALTERNATELY. If two
or more pumps of the same size are in-
stalled, alternate their use to equalize weai,
keep motor windings dry, and distribute
lubricant in bearings.

^3 Cross-Connection. A connection between a drinking (potable) water system and an unapproved water supply For example, if you
have a pump moving nonpotable water and hook into the ^rinkmg water system to supply water fc the pump seal, a cross-connection
or mixing between the two water systems can occur. This mixing may lead to contamination of the drinking water.

266 Water Treatment

MAN
WORKING
ON LINE

DO NOT CLOSE THIS
SWITCH WHILE THIS
TAG IS DISPLAYED

SIGNATURE .

This IS the ONLY person authorized to remove (his tag

NOTE: Tag also should include: TIME OFF

DATE

Fig. 18.22 Typical warning tag

(Source- Industrial Indemnity/Industrial UiKierwnters/irjsuiance Cos )

287

Maintenance 267

Frequency
of

Service
W

D
W

4. INSPECT PUMP CONTROL Inspect the
pump controls to see that the pump re-
sponds properly to changes In tne control-
ling variable. This variable may be either a
pressure or a water level. This check could
be done physically or by analyzing recording
gage records.

5. CHECK MOTOR CONDITION. See Para-
graph 6: Electric Motors.

e CHECK PACKING GLAND ASSEMBLY.
Check packing gland, the unit's most
abused and troublesome part. If stuffing
box leaks excessively when gland is pulled
up with miid pressure, remove packing and
examine shaft sleeve carefully. Replace or

repair grooved or scored shaft sleeve be-
cause packing cannot be held in stuffing
box with roughened shaft or shaft sleeve.
Replace the packing a stnp at a time, tamp-
ing each stnp thoroughly and staggering
joints. (See Fig. 18.23.) Position lantern ring
(water-seal ring) properly. If grease sealing
IS used, completely fill lantern ring with
grease before putting remaining rings of
packing in place. The type of packing used
(Fig. 18.24) IS less important than the man-
ner in which packing is placed. Never use a
continuous strip of packing. This type of
packing wraps around and scores the shaft
sleeve or is thrown out against outer wall of
stuffing box. allowing water to leak through
and score the shaft. The proper size of
packing should be available in your plant's
equipment files. See Fig. 18.25 for illustrat-
ed steps on how to pack a pump.

Fig. 18.23 Method of packing shaft

(Sourco war Department Tochntcal Manual TM5'666)

288

ERIC

268 Water Treatment

Teflon Packing

Graphite Packing

Fiy. 18.24 Packing

(Courtesy A w Chesteron Co )

Er|c 28 ^

Maintenance 269

-^T7

1 Remove oil old pocking. Akn pocking
* hook ot bor« of th0 box keep from
scrotching the shoft. Otsn box thor-
oughly so the new pocking won't hong up

Check 7or bent rod, grooves or shoul-
d'*rs. If the neck bushing clearance
in bottom of box is great, use stfffer
bottom ring or reploce the neck bushb>g

3 Revolve rotory shaft. If the Indlcotor
runs out over 0.003-in., straighten
shoft, r check bearings, or bakince
rotor. Gyroting shoft beats out pocking

Wrong

6 Cutting off rings while pocking Is
¥rrapped around shoft will give you

rings with parallel ends,
important if packing is

fhis is very
to do job

7 11 you cut pocking while stretched out straight, the ends will be at on angle.
With gap at angle, packing on either skle squeezes into top of gap ond ring,
cannot close. This brings up the questton otout gap for expansion. Mo& pocktngs
need none. Channel-type packing with lead core may need slight gap for exponsK>n

HOW

TO PACK

A PUMP

(Editor's Note: This step-by-step il-
lustration of a basic maintenance
duty was brought to our attention
by Anthony J. Zigment, Director,
Municipal Training Division, De-
partment of Community Affairs.)

wrong

11 Open ring joint sidewise, especkslly
II lead-filled and metallic types. This
prevents distorting molded circumfer-
ence— breaking the ring opposite gap

10 Use split wooden bushing. Install
1^ first turn of pocking, then force
into bottom of box by tightening gland
cgoinst bushing. Seot each turn this way

Doss expansion Sectional Diagonal

1C Always install cross-exponskm pocking so plies slope toward the fluid pres-
Iv sure from housing. Place sectkinol rings so slope between inside and outskie
ring is toward the pressure. Dkigonal rings must riso hove slope toward the fluid
pressure. Wotch these details for best results when installing new packing in o box

ERIC

fig. 18.25 How to pack a pump

(Source Water Pollution Control Assoctatton of Pennsylvania Magazine. January-February. 1976)

23-)

270 Water Treatment

J To find the right size of packing to C Wind pocking, needed for filling stuffing box, snugly around rod (for sorne size

t instoll, meosure stuffing-box bore ond v shoft held in vise) ond cut through eoch turn while coiled, Js shown. If the

subtrocr rod diometer, divide by 2. pockmg is slightly too lorge, never flotten with o hommer. Place each turn on

Pocking js too critical for guesswork, o cleon newspoper ond then roll out with pipe as you would ¥ ith a rolling pin

8 Install fotl'wropped pocking so edge^
on inside will foce direction of shoft
rototion. This is o must; otherwise, thin
edges flake off, reduce pocking life

, Neck bushing

9 Neck bushing slides into stuffing
box. Quick woy to moke it is to pour
soft Leonng metol into tin con, turn
ond bore for sliding fit into ploc*

in scabbing new metollic pockfaigs with
iubricont supplied by pocking maker
is OK. These include foil types, !ead^
core, etc. If the rod is oily, don't swob It

10 Stogger joints 180 degrees if only
■ V two rings ore in stuffing box. Spoce
ot 120 degrees for three rings, or 90
degrees if four rings or mOre ore in set

Lonrern rtng^

■KIBCB

1 i Instoll pocking so Jontern ring lines up with cooling-liquid opening. Also, remem*
■ ■ ber that this ring moves bock into box os pocking is compressed. Leave space
for glond to enter os shown. Tighten glond with wrench — bock off finger^tight.
Allow the pockmg to leak until it seots itself, then ollow o slight operortng leokoge

Hydroulic-packing pointers

First, clean stuffing box, examine ram or rod. Next, measure stuffing-box
depth and packing set— find difference. Place %-in. washers over gland
studs as shown. Lubricate ram and packing set fif for water). If you
can use them, endless rings give about 17% more wear than cut rings.
Place male adapter in bottom, then carefully slide each packing turn
home— don't harm lips. Stagger joints for cut rings. Measure from lop
of packing to top of washers, then compare with gland. Never tighten
down new packing set until all air has chance to work out. As packing
wears, remove one set of washers, after more wear, remove othe*- washer.

ERLC

Fig. 16,25 How to pack a pump (continued)

2dl

Maintenance 271

Frequency
of
Service

If a bronze shaft sleeve is not too badly
scored, the shaft sleeve can be restored to
service. The repair procedure consists of
turning the sleeve down to a uniform diame-
ter with a rough cut. Then spray the sleeve
with stainless steel to a slightly oversized
outside diameter followed by machining and
polishing to bring the sleeve back to its
original diameter. You will probably find that
these reworked sleeves will outlast the
originals.

W 7. CHECK MECHANICAL SEALS. Mechanical
seals usually consist of two sub-assem-
blies: (1) a rotating ring assembly, and (2) a
stationary assembly.

Inspect seal for leakage and excessive heat.
If any part of the seal needs replacing,
replace the entire seal (both sub-assem-
blies) with a new seal that has been pro-
vided by the manufacturer. Before installing
a new seal, be sure that there are no chips
or cracks on the carbide sealing surface.
Keep a new mechanical seal clean at all
times

Always be sure that a mechanical seal is
surrounded with water before starting and
running the pump.

Q 8. INSPECT AND LUBRICATE BEARINGS.

Unless otherwise specifically directed for a
particular pump model, lubricate according
to the procedures covered in Section
18.224, page 263. Check sleeve bearings to
see that oil rings turn freely with the shaft.
Repair or replace if deJective.

Measure sleeve bearings and replace those
worn excessively. Generally, allovy clear-
ance of 0.002 inch plus 0.001 Inch for each
inch or fraction of inch of shaft-journal diam-
eter.

Q 9. CHECK OPERATING TEMPERATURE OF
BEARINGS. Check bearing temperature
with thermometer, not by hand. If antifriction
bearings are running hot, check for over-
lubrication and relieve if necessary If sleeve
bearings run too hot, check for lack of
lubricant. If proper lubrication does not cor-
rect condition, disassemble and inspect
bearing. Check alignment of pump and mo-
tor if high temperatures continue.

S 10. CHECK ALIGNMENT OF PUMP AND MO-
TOR. For method of aligning panp and
motor, see Paragraph 10: Couplings. If mis-
alignment recurs frequently, inspect entire
piping system. Unbolt piping at suction and
discharge nozzles to see if it springs away,
indicating strain on casing. Check all piping
supports for soundness and effective sup-
port of load.

Vertical pumps usually have flexible shafting
which permits slight angular misalignment;

however, if solid sJiafting is used, align
exactly. If beams carrying intermediate
bearings are too light or are subject to
contraction or expansion, replace beams
and realign intermediate bearings carefully.

1 1 INSPECT AND SERVICE PUMPS.

a Remove rotating element of pump and
inspect thoroughly for wear. Order re-
placement parts where necessary-
Check impeller clearance between vo-
lute

b. Remove any deposit or scaling. Clean
out v/ater-seal piping.

c. Determine pump capacity by pumping
into empty tank of known size or by
timing the draining of pit or sump.

Pump Capacity, GPM

Volume, gallons
Time, minutes

Pump Capacity,

liters Volume, liters

sec Time, seconds

ERIC

See EXAMPLE 1 for procedures on how
to calculate pump capacity.

d. Test pump efficiency. Refer to pump
manufacturer's instructions on how to
collect data and perform calculations.
Also see pages 147 and 148 in SMALL
WMER SYSTEM OPERATION AND
MAINTENANCE of this series of man-
uals.

e. Measur<? total dynamic suction head or
lift and discharge head to test pump and
pipe condition. Record figures for com-
parison with later tests.

f. Inspect foot and check valves, paying
particular attention to check valves,
which can cause water hammer when
pump stops. (See Paragraph 13: Check
Valves also.) Foot valves are a type of
check valve which are used when pump-
ing raw water.

g. Examine wearing rings. Replace serious-
ly worn wearing rings to improve efficien-
cy. Check wearing ring clearances which
generally should be no more than 0.003
inch per inch of wearing diameter.

CAUTION: To protect rings and castings,
never allow pump to run dry through lack
of proper priming when starting or loss of
suction when operating.

12. DRAIN PUMP FOR LONG-TERM SHUT-
DOWN. When shutting down pump for a
long pcnod, open motor disconnect switch;
and if so equipped, turn on the electnc
motor winding heaters. Shut all valves on
suction, discharge, water-seal, and priming
lines; dram pump completely by removing
vent and drain plugs. This procedure pro-
tects pump against corrosion, sedimenta-
tion, and freezing. Inspect pump and bear-
ings thoroughly and perform all necessary

2ii:i

272 Water Treatment

Frequency
of
Service

servicing. Drain bearing housings and re-
plenish with fresh oil. purge old grease and
replace. When a pump is out of service, run
it monthly to warm It up and to distribute
lubncalion so the packing will not "freeze" lo
the shaft. Resume periodic checks after
pump is put back in service.

FORMULAS

To find the volumes of a rectangle In cubic feet, multiple
the length times width times depth.

Volume, cu ft = (Length, ft) (Width, ft) (Depth, ft)

To find the volume of a cylinder in cubic feet, multiply
0.785 times the diameter squaied times the depth.

Volume, cu ft = (0.785) (Diameter, ft}^ (Depth, ft)

To convert a volume from cubic feet to gallons, multiply
the volume in cubic feet times 7.48 gallons per cubic foot.

Volume, gal = (Volume, cu ft) (7.48 gal/cu ft)

To calculate the output or capacity of a pump in gallons
per minute, divide the volume pumped in gallons by the
pumping time in minutes.

no* r^r^^M Volume Pumped, gallons

Pump Capacity, GPM = — —

Pumping Time, minutes

EXAMPLE 1

A pump's capacity is measured by recording the time in
minutes for water to rise 3 feet in an 8-foot diameter tank.
What is the pumping rate or capacity in gallons per minute
when the pumping time is 9 minutes?

Known Unknown

Diameter, ft = 8 ft Pump Capacity. GPM

Depth, ft = 3 ft
Time, min = 9 min
Calculate the tank volume in cubic feet.

Volume, cu ft = (0.785) (Diameter, ft)^ (Depth, ft)

= (0.785) (8 ft)2 (3 ft)

= 151 cu ft

Convert the tank volume from cubic feet to gallons.
Volume, gal = (Volume, cu ft) (7.48 gal/ru ft)

= (151 cu ft) (7 48 gal/cu ft)

= 1129 gallons

Calculate the pump capacity in gallons per minute.

^ . _ Volume Pumped, qal

Pump Capacity, GPM = ^ ' ^

Pumping Time, min

_ 1129 gallons

9 min

= 125 GPM

ERLC

QUESTIONS

Wnte your answers m a notebook and then compare your
answers with those on page 325.

18 23A What is a cross-connection'?

18.23B Is a slight water-seal leakage desirable when a
pump is running? If so, why?

18.23C How would you measure the capacity of a pump?

18.23D Estimate the capacity of a pump (In GPM) if it
lowers the water in a 10-foot wide by 15-foot long
wet well 1.7 feet in five minutes.

1 8.23E What should be done to a pump before !t Is shut
down for a long time, and why?

Paragraph 2: Reciprocating Pumps, General

The general procedures in this paragraph apply lo all
reciprocating pumps described in this section.

Frequency
of

Service

W 1. CHECK SHEAR PIN ADJUSTMENT. Set ec-
centric by placing shear pin through proper
hole In eccentric f'anges to give required
stroke. Tighten the two Vs- or %-inch hexag-
onal nuts on connecting rods just enough to
take spring out of lock washers. (See Para-
graph 11: Shear Pins). When a shear pin
fails, eccentric moves toward neutral posi-
tion, preventing damage to the pump. Re-
move cause of obstruction and Insert new
shear pin. Shear pins fall because of one of
three common causes:

(1) Solid object lodged under piston,

(2) Clogged discharge line, and

(3) Stuck or wedged valve.

D 2. CHECK PACKING ADJUSTMENT. Give
special attention to packing adjustment. If
packing is too tight. It reduces efficiency and
scores piston walls. Keep packing just tight
enough to keep s'udge from leaking through
gland. Before pump is installed or after it
has been idle for a time, loosen all nuts on
packing gland. Run pump with sludge suc-
tion line closed and valve covers open for a
few minutes to break In the packing. Turn
down gland nuts no more than necessary to
prevf-ni sludge from getting past packing.
Tighten all packing nuts uniformly.

When packing gland bolts cannot be taken
up farther, remove packing. Remove old
packing and thoroughly clean cylinder and
piston walls. Place new packing Into cylin-
der, staggering packing-ring joints, and
tamp each ring into place. Break In and
adjust packing as explained above. When
chevron type P'-^.king is used, tighten gland
nuts only finger tight becauss excessive
pressure ruins packing and scores plunger.

Q 3. CHECK BALL VALVES. When vaVe balls
are so worn that diameter Is Ve inch (1 .5 cm)
smaller than original size, they may jam Into

Maintenance 273

Frequency
of
Service

guides in valve chamber. Check size of
valve balls and replace if badly worn.

Q 4. CHECK VALVE-CHAMBER GASKETS.

Valve-chamber gaskets on most pumps
serve as a safety device and blow out under
excessive pressure. Check gaskets and re-
place if necessary. Keep additional gaskets
on hand for replacement.

A 5. CHECK ECCENTRIC ADJUSTMENT. To
take up babbitt bearing, remove brass
shims provided on connecting rod. After
removing shims, operate pump for at least
one hour and check to see that eccentric
does not run hot.

D 6. NO^E UNUSUAL NOISES. Check for no-
ticoable water hammer when pump is oper-
ating. This noise is most pronounced when
pumping water or very thin sludge; it de-
creases or disappears when pumping heavy
sludge. Eliminate noise by opening the V4-
inch (0.6 cm) petcock on pump body slightly:
this draws in a small amount of air, keeping
discharge air chamber full at all times.

D 7. CHECK CONTROL VALVE POSITIONS. Be-
cause any plunger pump may be damaged if
operated against closed valves in the pipe-
line, especially the discharge line, make all
valve setting changes with pump shut down;
otherwise pumps which are installed to
pump from two sources or to deliver to
separate tanks at different times may be
broken if all discharge line valves are closed
simultaneously for a few seconds or dis-
charge valve directly above pump is closed.

W 8. GEAR REDUCER. Check oil level by remov-
ing plug on the side of the gear case Unit
should not be in operation.

Q 9. CHANGE OIL AND CLEAN MAGNETIC
DRAIN PLUG.

W 1 0. CONNECTING RODS. Set oilers to disperse
two drops per minute.

W 11. PLUNGER CROSSHEAD. Fill plunger as re-
quired to half cover the wrist pin with oil.

D 12. PLUNGER TROUGH. Keep small quantity of
oil in trounh to lubricate the plunger.

M 13 MAIN SHAFT BEARING. Grease bearings
monthly. Pump should be in operation when
lubricating to avoid excessive pressure on
seals.

14. CHECK ELECTRIC MOTOR. See Para-
graph 5: Electric Motors.

Paragraph 3: Propeller Pumps, General

D 1. CHECK MOTOR CONDITION. See Para-
graphs 6.1 and 6.2.

D 2. CHECK PACKING GLAND ASSEMBLY. See
Paragraph 1.6.

W 3. INSPECT PUMP ASSEMBLY. See Para-
graph 1.4.

W 4. LUBE LINE SHAFT AND DISCHARGE
BOWL BEARING. Maintain oil in oiler at all
times. Adjust feed rate to approximately
four drops per minute.

W 5. LUBE SUCTION BOWL BEARING. Lube
through pressure fitting. Usually three or
four strokes of gun are enough.

W 6. OPERATE PUMPS ALTERNATELY. See
Paragraph 1.3.

A 7. LUBE MOTOR BEARINGS. See Paragraph
6.3.

Paragraph 4: Progressive Cavity Pumps, General

(Fig. 18.20, page 260).

D 1 CHECK MOTOR CONDITION. See Para-
graphs 6.1 and 6.2.

D 2. CHECK PACKING GLAND ASSEMBLY. See
Paragraph 1.6.

D 3. CHECK DISCHARGE PRESSURE. A higher
than normal discharge pressure may indi-
cate a line blockage or a closed valve down-
stream. An abnormally low discharge pres-
sure can mean reduced rate of discharge.

S 4. INSPECT AND LUBRICATE BEARINGS —
GREASE. If possible, remove bearing cover
and visually inspect grease. When greasing,
remove relief plug and cautiously add 5 or 6
strokes of the grease gun. Afterwards,
check bearing temperature with thermom-
eter. If over 220''F (104*^0), remove some
grease.

5. LUBEFLUSH MOTOR BEARINGS. See
Paragraph 6.3.

6. CHECK PUMP OUTPUT Check how long it
takes to fill a vessel of known volume or
quantity; or check performance against a
meter, if available. See Paragraph 1.1 I.e.

S
S

7. SCOPE MOTOR BEARINGS. See Para-
graph 6.4.

8. SCOPE PUMP BEARINGS. See Paragraph
6.4.

Paragraph 5: Pump Controls

To ensure the best operation of the pump, a systematic
inspection of the controls should be made at least once a
week.

W 1. CHECK CONTROLS. Controls respond to
the control variable.

W 2. STARTUP. The unit starts when the control
^.yotem makes contact, and the pump stops
at the prescribed control setting.

W 3. MOTOR SPEED. The motor comes up to
speed quickly and is maintained.

W 4. SPARKING. A brush-type motor does not
spark profusely in starting or running.

2<J4

274 Water Treatment

Frequency
of

Service
W

INTERFERENCE WITH CONTROLS.
Gr se and d»rt are not interfering with
conn uls.

ADJUSTMENTS. Any necessary adjust-
ments are properly completed.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 325.

1 8.23F What are some of the common causes of shear pin
failure in reciprocating pumps?

18.23G What may happen when water or a thin sludge is
being pumped by a reciprocating pump?

18.23H What could be the causes of a higher than normal
discharge pressure in a progressive cavity pump?

Paragraph 6: Electric Motors (Fig. 18.26)

In order to ensure the proper and continuous function of
electric motors, the items listed in this paragraph must be
performed at the designated imervals. If operational checks
indicate a motor is not functioning properly, these items will
have to be checked to locate the Drobiem.

D 1. CHECK MOTOR CONDITIONS.

a. Keep motors free from dirt, duot and
moisture.

b. Keep operating space free from articles
which may obstruct air circulation.

c. Check for excessive grease leakage
from bearings.

D 2. NOTE ALL UNUSUAL CONDITIONS.

a. Unusual noises in operation.

b. Motor failing to start or come to speed
normally, sluggish operation.

c. Motor or bearings which feel or smell
hot.

d. Continuous or excessive sparking com-
mutator or brushes. Blackened commu-
tator.

e. Intermittent sparking at brushes.

f. Fine dust under coupling having rubber
buffers or pins.

g. Smoke, charred insulation, or solder
whiskers extending from armatu''e.

h. Excessive humming.

i. Regular clicking,
j. Rapid knocking.

Frequency
of
Service

k. Brush chatter.

I. Vibration.

m. Hot commutator.

A 3 LUBRICATE BEARINGS (Fig. 18.27). Check
grease in ball bearing and relubricate when
necessary.

Follow instructions in Section 18.224, Pump
Lubrication, when lubricating greased bear-
ings.

A 4. USING A STETHOSCOPE.^^ CHECK BOTH
BEARINGS. Listen for whines, gratings, or
uneven noises. Listen all around the bearing
and as near as possible to the bearing.
Listen while the motor is being started and
shut off. If unusual noises are heard, pin-
point the location.

5. IF YOU THINK THE MOTOR is running
unusually hot, check with a thermometer.
Place the thermometer on the casing near
the bearing, holding it there with putty or
clay. Check the current on each leg to
determine if the currents are balanced and
within the motor name plate limits.

A 6. DATEOMETER}^ If there is a dateome er
on the motor, after changing the oil in the
motor, loosen the dateometer screw and set
to the corresponding year.

QUESTiONS

Write your answers in a notebook and then compare your
answers with those on page 325.

18.231 What are the major items you would include when
checking an electric motor?

18.23J What is the purpose of a stethoscope?

Paragraph 7: Belt Drives

Frequency
of
Service

1. GENERAL. Mamtaii-ing a proper tension
and alignment of belt drives ensures long
life of belts and sheaves. Incorrect align-
ment causes poor operation and excessive
belt wear. Inadequate tension reduces the
belt gnp, causes high belt loads, snapping,
and unusual wear.

a. Cleaning belts. Keep belts and sheaves
clean and free of oil, which causes belts
to deteriorate. To remove oil, take belts
off sheaves and wipe belts and sheaves
with a rag moistened in a non-oil base
solvent. Carbon tetrachloride is NOTrec-

I* Stethoscope. An instrument used to magnify sounds and convey them to the ear

ERIC

Maintenance 275

DRIP PROOF

ITEM

PART NAME

NO.

Wound Stator w/ Frame

Rotor Assembly

Rotor Core

Shaft

Bracket

Bearing Cap

Bearings

Seal, Labyrinth
Thru Bolts /Caps

Seal, Lead Wire

Terminal Box

Terminal Box Cover

Fan

Deflector

Lifting Lug

11*5

TOTALLY ENCLOSED PAN COOLED

ITEM

NO.

PART NAME

Wound Stator w/ Frame

Rotor Assembly

Rotor Gore

Shaft

Brackets

Bearings

Seal, Labyrinth

Thru Bolts /Caps

Seal, Lead Wire

Terminal Box

Terminal Box Cover

Fan J Inside

''an. Outside

Fan Grill

Fan Cover

Fan Cover Bolts

Lifting Lug

Fig. 18.26 Typical motors

{C'^Mosi of Sterling Power Systems. Inc )

276 Water Treatment

ELECTRIC MOTOR

MOTOR LUBRICATION

FRONT BEARING BRACKET
FRONT AIR DEFLECTOR
FAN
ROTOR

FRONT BEARING
END COVER
STATOR

8 SCREENS

9 CONDUirBOX

10 BACK AIR DEFLECTOR

11 BACK BEARING

12 BACK BEARING BRACKET

13 OIL LUBRICATION CAP

Fig. 18.27 Electric motor lubrication

ERIC

Maintenance 277

Frequency
of

Service

ommended because exposure to its
fumes has many toxic effects on hu-
mans. Carbon tetrachloride also is ab-
sorbed into the skin on contact and its
effects become stronger with each con-
tact.

b. Installing belts. Before installing belts,
replace //orn or damaged sheaves, len
slack off on adjustments. Do not try to
force belts into position. Never use a
screwdriver or similar lever to get belts
onto sheaves. After belts are installed,
adjust tension; recheck tension after
eight hours of operation. (See Table
18.3).

c. Replacing belts. Replace belts as soon
as they become frayed, worn, or
cracked. NEVER REPLACE ONLY ONE
V-BELT ON A MULTIPLE DRIVE. Re-
place the complete set with a set of
matched belts, whi'. h can be obtained
from any supplier. All belts in a matched
set are machine-checked to insure equal
size and tension.

d. Storing spare belts. Store spare belts in a
cool, dark place. Tag all belts in storage
to identify them with the equipment on
which they can be used,

2. V-3ELTS. A properly adjusted V-belt has a
slight bow in the slack side when running;
when idle it has an alive springiness \NUen
thumped with the hand. An improperly tight-
ened helt feels dead when thumped.

If the slack side of the drive is less than 45°
from the horizontal, vertical sag at the cen-
ter of the span may be adjusted in accor-
dance With table 18.3 below:

TABLE 18.3 HORIZONTAL BELT TENSION

span
(inches)

100

150

200

Vertical
Sag

From

1 80

3 30

(inches)

2 30

4 90

8 60

Span
(miiiimoters)

250

500

1250

2500

3750

5000

Vertical
Sag

From

0 25

0 75

5 00

POO

45 0

82 5

(rniUimeters)

0 75

2 25

14 50

57 5

122 5

2150

M a. Check tension. If tightening belt to proper

tension does not cc ect slipping, check
for overload, oil on belts, or other possi-
ble causes. Never use belt dressing to
stop belt slippage. Rubber wearings near
the drive are a sign of improper tension.
Incorrect alignment, or damaged
sheaves.

M b. Check sheave (pulley) alignment. Lay a

long straight edge or string across out-
side faces of pulley, and allow for differ-
ences in dimensions from center lines of
grooves to outside faces of the pulleys

ERLC

being aligned. Be especially careful in
aligning drives with more than one V-be't
on a sheave, as misalignment can cai<se
unequal tension

Parrigraph 8: Chain Drives

1. GENERAL. Cham drives may bo designated
for slow, medium, or high speeds.

a. Slow-speed drives. Because slow-speed
drives are usually enclosed, adequate
lubrication 5s difficult. Heavy oil applied to
the outside of the chain seldom reaches
the working parts; in addition, the oil
catches dirt and grit and becomes abra-
sive. For lubricating and cleaning meth-
ods, see 5 and 6 below.

b. Medium- and high-speed drives. Medi-
um-speed drives should be continuously
lubricated with a device similar to a sight-
feed oiler. Highspeed drives should be
completely enclosed in an oil-tight case
and the oil maintained at proper level.

D 2. CHECK OPERATION. Check general oper-
ating condition during regular tours of duty.

Q 3. CHECK CHAIN SLACK. The correct amount
of slack IS essential to proper oneration of
chain drives. Unlike other belts, chain belts
should not be tight around the sprocket;
when chains are tight, working parts carry a
much heavier load than necessary. Too
much slack is also harmful; on long centers
particularly, too much slack causes vibra-
tions and chain whip, reducing life of both
chain and sprocket. A properly installed
Cham has a slight sag or looseness on the
return run.

S 4. CHECK ALIGNMENT. If sprockets are not in
line or if shafts are not parallel, excessive
sprocket and chain wear and early chain
failure result. Wear on inside of chain, side
walls, and sides of sprocket teeth are signs
of misalignment. To check alignment, re-
move chain and place a straight edge
against sides of sprocket teeth.

S 5. CLEAN. On enclosed types, flush chain and
enclosure with a petroleum solvent (kero-
sene). On exposed types, remove chain and
soak and wash it in solvent. Clean sprock-
ets, install chain, and adjust tension.

S 6. CHECK LUBRICATION. Soak exposed-type
chains in oil to restc.e lubricating film. Re-
move excess lubricant by hanging chains up
to drain.

Do not lubricate underwater chains which
operate in contact with considerable grit. If
water is clean, lubricate by applying water-
proof grease with brush while chain is run-
ning.

Do not lubricate chains on elevators or on
conveyors of feeders A^hich handle dirty or
gritty materials. Dust and grit combine with
'ubricants to form a cutting compound which
reduces chain life.

278 Water Treatment

Frequency
of

Service

S 7. CHANGE OIL. On enclosed types only, dra.n
Oil and refill case to proper level.

S 8. INSPECT. Note and correct abnormal condi-
tions before scnous damage results. Do not
put a new chain on worn sprockets. Always
replace worn sprockets when replacing a
chain because out-of-pitch sprockets cause
as much chain wear in a few hours as years
of normal operation.

9. TROUBLESHOOTING. Some common
symptoms of improper chain-drive oper-
ation and their remedies follow:

a. Excessive noise. Correct alignment, if
misaligned. Adjust centers for proper
Cham slack. Lubricate In accordance with
aforementioned methods. Be sure all
bolts are tight. If chain or sprockets are
worn, reverse or renew if necessary.

b. Wear on chain, side walls, and sides of
teeth. Remove chain and correct align-
ment.

c. Chain climbs sprockets. Check for poorly
fitting sprockets and replace if neces-
sary. Make sure tightener is installed on
dnve Cham.

d. Broken pins and rollers. Check fo-^ chain
speed which may be too high ,or the

pitoii. UMU buuotuuic oiidiii dfiO bpfUCKetS

with shorter pitch if necessary. Breakage
abo may be caused by shock loads.

e. Cham clings to sprockets Check for in-
correct or worn sprockets or heavy,
tacky lubricants. Replace sprockets or
lubricants i' necessary.

f. Cham whip. Check for too-long centers
or high, pulsating loads and correct
cause.

g. Chains get stiff. Check for misalignment,
improper lubncation, or excessive over-
loads. Make necessary corrections or
adjustments.

Paragraph 9; Variable Speed Belt Drives (See Fig 18.28)

D 1- C'-EAN DISCS. Remove grease, acid, and
water from disc faces.

D 2. CHECK SPEED-CHANGE MECHANISM.

Shift drive through entire speed range to
make sure shafts and bearings are lubricat-
ed and discs move freely in lateral direction
on shafts.

W 3. CHECK V-BELT. Make sure it runs level and
true. If one side rides high, a disc is sticking
on shaft because of insufficient lubncation
or wrong lubricant. In this case, stop the
drive at once, remove V-belt, and clean disc
hub and shaft thoroughly with petroleum
solvent until disc moves freely. Relubricate
with soft ball-beanng grease and replace V-

ERIC

Frequency
of

Service

belt in opposite direction from that in which
It formerly ran.

M If drive is not operated for 30 days or more,

shift unit to minimum speed position, plac-
ing spnng on vanable-speed shaft at mini-
mum tension and relieving belt of excessive
pressure.

4 LUBRICATE DRIVE. Make sure to apply
lubricant at all the six force-feed lubrication
fittings (Fig. 1 8.28: A, B, D, E, G and H) and
the one cup type fitting (C).

NOTE: If the drive is used with a reducer,
fitting E IS not provided.

W a. Once every ten days to two weeks, use

two or three strokes of a grease gun
through fittings A and B at ends of shift-
ing screw and variable-speed shaft, re-
spectively, to lubricate bearings of mov-
able discs. Then, with unit running, shift
drive from one extreme speed position to
the other to ensure thorough distribution
of lubricant over disc-hub bearings.

0 b. Add two or three shots of grease through

fittings D and E to lubricate frame bearing
on variable-speed shaft.

Q c Every 90 days, add two or three cupfulls

of grease to Cud C which lubricates
thrust bearing on constant-speed shaft.

Q d. Every 90 days, use two or three strokes

of grease gun through fittings G and H to
lubncate motorframe beanngs.

CAUTION: Be sure to follow manufactur-
er's recommendation on type of grease.
After lubricating, wipe excessive grease
from sheaves and belt.

QUESTIONS

Write your answers in a notebook and then compare your
ansv^ers with those on page 325.

18 23K How can you tell if a belt on belt-drive equipment
has proper tension and alignment

18 23L Why should sprockets be replaced when replacmg
a Cham in a chain-drive unif

Paragraph 10: Couplmgs

1 GENERAL. Unless couplings between the
driving and driven elements of a pump or
any other piece of equipment are kept in
proper alignment, breaking and excessive
weai results m either or both the driven
machinery and the driver. Burned-out bear-
ings, sprung or broken shaft, and exces-
sively worn or ruined gears are some of the
damages caused by misalignment. To pre-
vent oui^ages and the expense of installing
replacement parts, check [he alignment of
all equipment before damage occurs.

29j

Maintenance 279

NOTE A, B, D, E, G and H are force-feed lubrication fittings.
C ts a cup type lubncation fitting

Fig 18.28 Reeves ' aridnve

(Source war Departmenl Technical Manual TMS-666)

Frequency
of
Service

a. Improper original installation of the
equipment may not necessarily be the
cause of the trouble. Settling of founda-
tions, heavy floor loadings, warping of
bases, excessive bearing wear, and
many other factors cause misalignment.
A ngid base is not always security
against misalignment. The base may
have been mounted off level, which could
cause it to warp.

b. Flexible couplings permit easy assembly
of equipment, but they must be aligned
as exactly as flanged couplings if maintp-
nance and r«»pair are to be kept a
minimum. Rubber-bushed *ypes cannot
function properly if the bolts cannot
move in their bushings.

S 2. CHECK COUPLING ALIGNMENT (straight
edge method). Excessive bearing and motor
temperatures caused by overload, notice-
able vibration, or unusual noises may all be
warnings of misalignment. Realign when

necessary (Fig 18 29) using a straight edge
and thickness gage or wedge. To ensure
satisfactory operation, level up to within
0.005 inch (0.13 mm) as follows:

a. Remove coupling pins.

b. Rigidly tighten driven equipment; slightly
tighten bolts holding drive.

c To correct horizontal and vertical misa-
lignment, shift cr shim drive to bring
coupling halves into position so no I'ght
can be seen under a straight edge laid
across them. Place straight edge in four
positions, holding a light in back of
straight edge to help ensure accuracy.

d. Check for angular misalignment with a
thickness or feeler gage inserted at four
placfts to make certain space between
coupling halves is equal.

e. If proper alignment has been secured,
coupling pins can be put in place easily
using only finger pressure. Never ham-
mer pins into place.

f. If equipment is still out of alignment,
repeat the procedure.

30'.j

280 Water Treatment

— STRAIGHT EDGE

FEELER GAGE -

ANGULAR MISALIGNMENT

FEELER GAGE
PERFECT ALIGNMENT

Fig. 18.29 Testing alignment straight edge

(Source Unknown)

Frequency
of
Service

S 3 CHECK COUPLING ALIGNMENT (dial indi-
cator method). Dial indicators also are used
to measure coupling alignment. This meth-
od produces better results than the straight
edge method. The dial indicates very small
movements or distances which are meas-
ured in mils (one mil equals 1/1000 of an
inch). The indicator consists of a dial with a
graduated face (with "plus" and "minus"
readings, a pedestal, and a rigid indicator
bar (or "fixture") as shown in Figure 18.30).

The dial indicator Is attached to one cou-
pling via the fixture and adjusted to the zero
position or reading. When the shaft of the
machine Is rotated, misalignment will cause
the pedestal to compress (a "plus" reading),
or extend (a "minus" reading). Literature
; ovided by the manufacturer of machinery
usually will indicate maximum allowable tol-
erances or movement.

Carefully study the manufacturer's literature
provided with your dial Indicator before at-
te.npting to use the device.

A 4. CHANGE OIL IN FAST COUPLINGS. Drain
out old oil and add oil to proper level.
Correct quantity is given on instruction card
supplied with each coupling.

Paragraph 11: Shear Pins

Some water treatment units use shear pins as protective
devices to prevent damage In case of sudden overloads. To
serve this purpose, these devices must be In operational
condition at all times. Under some operating conditions,
shearing surfaces of a shear pin device may freeze together

so solidly that an overload fails to break them.

Me lufacturers* drawings for particular installations usual-
ly specify shear pin material and size. If this information is
not available, obtain the information from the manufacturer,
giving the model, serial number, and load conditions of unit.
When necessary to determine shear pin size, select the
lowest strength which does not break under the unit's usual
loads. When proper size is determined, never use a pin of
greater strength, such as a bolt or a nail.

If necked pins are used, be sure the necked-down portion
IS properly positioned with respect to shearing surfaces.
When a shear pin breaks, determine and remedy the cause
of failure before inserting new pin and starting drive in
operation.

Frequency
of
Service

M 1 GREASE SHEARING SURFACES

Q 2. REMOVE SHEAR PIN. Operate motor for a
short time to smooth out any corroded
spots.

A 3. CHECK SPARE INVENTORY. Make sure an
adequate supply is on hand, properly Identi-
fied and with record of proper pin size,
necked diameter, and longitudinal dimen-
sions.

QUESTIONS

Write your answors in a notebook and then compare your
answers with those on page 325.

18.23M What factors could cause couplings to become out
of alignment?

ERIC

18.23N What is the purpose of shear pins'?

30}

Maintenance

INDICATOR BAR
(FIXTURE)

REVERSE
DIALING
PARALLEL
MISALIGNMENT

ILLUSTRATION INDICATES
A TOTAL OFFSET OF
40 MILS (20 MILS + 20 FlILS)

Fig. 18.30 Use of a dial indicator

(Permission of DYMAC. a Divieion of Spectral Dynamics Corporation)

302

282 Water Treatment

18.24 Pump Operation

18.240 Starting a New Pump

The initial startup work described in this paragraph should
be done by a competent and trained person, such as a
manufacturer's representative, consulting engineer, or an
experienced operator. The operator can learn a lot about
pumps and motors by accompanying and helping a compe-
tent person put new equipment into operation.

Before starting a pump, lubncate it according to the
lubncation instructions. Turn the shaft by hand to see that it
rotates freely. Then cl-eck to see that the shafts of the pump
and motor are ahg.ied and the flexible coupling adjusted.
(Refer to Paragraph 10: Couplings, page 278; also see
Section 18.23. "Pump Maintenance," page 265.) If the unit is
belt dijven, sheave (pulley) alignment and belt adjustment
should be checked. (Refer to Paragraph 7: Belt Drives.)
Check the electric voltage with tre motor characteristics and
inspect

the wiring See that thermal overload units in the starter are
set properly Turn on the motor just long enough to see that
it turns the pump in the direction indicated by the rotational
arrows marked on the pump. If separate water seal units or
vacuum pr.mer systems are used, these should be started.
Finally, make sure lines are open Sometimes there is an
exception (see following paragraph) in the case of the
discharge valve.

A pump should not be run without first having been
primed To pnme a pump, the pump must be completely
filled with water In some cases, automatic primers are
provided. If they are not, it is necessary to vent the casing.
Most pumps are provided with a valve to accomplish this.
Allow the trapped air to escape until v/ater flows from the
vent; then replace the vent cap. In the case of suction-lift
applications, the pump must be filled with water unless a
self-primer is provided. !n nearly every case, you may start a
pump with the discharge valve open. Exceptions to this,
however, are where water hammer or pressure surges
might result, or where the motor does not have sufficient
margin of safety or power. Sometimes there are no check
valves in the discharge iine. In this case (with the exception
of positive displacement pumps) it is necessary to start the
pump and then open the discharge lines. Where there are
common discharge headers, it is essential to start the pump
and then open the discharge valve A positive displacement
pump (reciprocating or piston types) should never be operat-
ed against a closed discharge line.

After starting the pump, again check to see that the
direction of rotation is correct. Packing-gla.id boxes (stuffing
boxes) should be observed for slight leakage (approximately
60 drops per minute) as described in Paragraph 1: Pumps,
General Check to see that the bearings do not overheat
from over- or under-lubncation. The flexible coupling should
not be noisy, if it is, the noise may be caused by misalign-
ment or improper clearance or adjustment. Check to be sure
pump anchorage is tight Compare delivered pump flows
and pressures with pump performance curves. If pump
delivery falls below performance curves, look for obstruc-
tions in the pipelines and inspect piping for leaks

18.241 Pump Shutdown

When shutting down a pump for a long period, the motor
disconnect switch should be opened, locked out, and tagged
with reason for tag noted. If the electric motor is equipped
with winding heaters, check to be sure they are turned on.
This helps to prevent condensation from forming which can
weaken the insulation on the windings. All valves on the
suction,^ discharge, and water-seal lines should be shut
tightly. Completely dram the pump by removing the vent and
dram plugs.

Inspect the pump and beanngs thoroughly so that all
necessary servicing may be done during the inactive period.
Dram the beanng housing and then add fresh lubricant.
Follow any additional manufacturer's recommendations.

18.242 Pump-Driving Equipment

Driving equipment used to operate pumps includes elec-
tric motors and internal combustion engines. In rare in-
s'tances, pumps are driven with steam turbines, steam
engines, air and hydraulic motors.

In all except the large installations, electnc motors are
used almost exclusively, with synchronous and induction
types being the most commonly used. Synchronous motors
operate at constant speeds and are used chiefly In large
sizes. Three-phase, squirrel-cage induction motors are most
often used in treatment plants. These motors require little
attention and, under average operating conditions, the fac-
tory lubncation of the bearing will last approximately one
year. (Check with the manufacturer for average number of
operating hours for beanngs.) When lubricating motors,
remember that too much grease may cause beanng trouble
or damage the winding.

Clean and dry all electncal contacts. Inspect for loose
electncal contacts. Make sure that hold-down bolts on
motors are secure. Check voltage while the motor is starting
and running. Examine beanngs and couplings

18.243 Electrical Controls

A variety of electncal equipment is used to control the
operation of pumps or to protect .electric motors. If starters,
disconnect switches, and cutouts are used, they should be
installed in accordance with the local regulations (city and/or
county '^odes) regardmg this equipment. In the case of larger
motors, the power company often requires starters which do
not overload the power lines.

The electrode-type, bubbler-type, and diaphragm-type
water level control systems are all similar in effect to the
float-switch system. Scum is a problem with most water-
level controls that operate pumps and must be removed on a
regular basis.

Maintenance 283

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 325.

1 8.24A Where would you find out how to lubricate a pump''

18 24B What problems can develop if too much grease is
used in lubricating a motor'?

18.244 Operating Troubles

The following list of operating troubles includes most of
the causes of failure or reduced operating efficiency. The
remedy or cure is either obvious or may be identified from
the description of the cause.

SYMPTOM A — PUMP WILL NOT START
CAUSES:

'i Blown fuses or tripped circuit breakers due to:

A. Rating of fuses or circuit breakers not correct,

B. Switch (breakers) contacts corroded or shorted,

C. Terminal connections loose or broken somewhere in
the circuit,

D. Automatic control mechanism not functioning prop-
erly,

E. Motor shorted or burned out,

F. Wiring hookup or service not correct,

G. Switches not set for operation,

H. Contacts of the control relays dirty and arcing,

I. Fuses or thermal units too warm,
J. Wiring short-circuited, and

K. Shaft binding or sticking due to rubbing impeller, tight
packing glands, or clogging of pump.

2. Loose connections, fuse, or thermal unit

SYMPTOM B — REDUCED RATE OF DISCHARGE
CAUSES:
1 Pump not primed

2. Air in the water

3. Speed of motor too low

4. Improper wiring

5. Defective motor

6. Discharge head too high

7. Suction lift greater than anticipated

8. Impeller clogged

9. Discharge line clogged

10. Pump rotating in wrong direction

11. Air leaks in suction line or packing box

12. Inlet to suction line too high, permitting air to enter

13. Valves partially or entirely closed

14 Check valves stuck or clogged

15 Incorrect impeller adjustment

16 Impeller damaged or worn
17. Packing worn or defective

18 impeller turning on shaft because of broken key

19 Flexible coupling broken

20 Loss of suction dunng pumping may be caused by leaky
suction line, ineffective water or grease seal

21 Belts slipping

22 Worn wearing ring

SYMPTOM C — HIGH POWER REQUIREMENTS
CAUSES'
1 Speed of rotation too high

2. Operating heads lower than rating for which pump was
designed, resulting in excess pumping rates

3. Sheaves on belt drive misaligned or maladjusted

4. Pump shaft bent

5 Rotating elements binding

6. Packing too tight

7. Wearing rings worn or binding

8. Impeller rubbing

SYMPTOM D — NOISY PUMP
CAUSES

1 Pump not completely primed

2 Inlet clogged

3. Inlet not submerged

4 Pump not lubricated properly

5. Worn impellers

6. Strain on pumps caused by unsupported piping fast-
ened to the pump

7 Foundation insecure

8. Mechanical defects in pump

9 Misalignment of motor and pump where connected by
flexible shaft

10 Rocks in the impeller

1 1 Cavitation

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 325.

18 24C What Items would you check if a pump will not
start''

18.24D How would you attempt to increase the discharge
from a pump if the flow rate is lower than expected?

304

284 Water Treatment

18.245 Starting and Stepping Pumps

The operator must determine what treatment processes
will be effected by either starting or stopping a pump. The
pump discharge point must be known and vaVes either
opened or closed to direct flows as desired by the operator
when a pump is started or stopped

1 8 2450 Centrifugal Pumps. Basic rules for the operation
of centrifugal pumps Include the following items

1. Do not operate the pump when safety guards are not
installed over or around moving parts.

2. Do not start a pump that has been locked or tagged out
for maintenance or repairs

3. Never run a centnfugal pump when the impeller is dry.
Always be sure the pump is primed.

4. Never attempt to start a centnfugal pump whose impeller
or shaft is spinning backwards.

5. Do not operate a centnfugal pump that is vibrating
excessively after startup. Shut unit down and isolate
pump from system by closing the pump suction and
discharge valves Look for a blockage in the suction line
and the pump impeller

There are several situations in whiuh It may be necc-ssary
to start a CENTRIFUGAL pump against a CLOSED dis-
charge valve. Once the pump Is primed, running and indicat-
ing a discharge pressure, slowly open the pump discharge
valve until the pump is fully on line. This procedure is used
With treatment processes or piping systems with vacuums
or pressures that cannot be dropped or allowed to fluctuate
greatly while an alternate pump is put on the line.

Most centrifugal pumps used in water treatment piei-its are
designed so that they can be easily started even if they
haven't been primed. This is accomplished with a positive
static suction head or a low suction lift. On most of t.iese
arrangements, the pump will not require priming as long as
the pump and the piping system do not leak. Leaks would
allow the water to drain out of the pump volute. When pumps
in water systems lose their prime, the cause is often a faulty
check valve on the pump discharge line. When the pump
stops, the discharge check valve will not seal (close) proper-
ly. Water previously pumped then flows back through the
check valve and through the pump. 1 he pump is drained and
has lost its prime.

About ninety-five perciint of the time, the centnfugal
pumps In v.dter treatment plants are ready to operate with
suction and discharge valves open and seal water turned on.
When the automatic start or stop comma ;d is received by
the pump from the controller, the pump is ready to respond
properly.

When the pumping equipment must be serviced, take it off
the line by locking and tagging out the pump controls until all
service work Is completed.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 325.

1 8.24E Why should a pump that has been locked or tagged
out for nriaintenance or repairs not be started?

1 8 24F Under what conditions might a centrifugal pump be
started against a closed discharge valve?

STOPPING PROCEDURES

This >ection contains a typical sequence of procedures to
follow to stop a centrifugal pump. Exact stopping proce-
dures for any pumping system depend upon the condition of
the discharge system. The sudden stoppage of a pump
could cause severe WATER HAMMER^^ problems in the
piping system.

1 Inspect process system affected by pump, start alternate
pump if required, and notify supervisor or log action.

2 Before stopping and operating pump, check its oper-
ation. This will give an indication of any developing
problems, required adjustments, or problem conditions of
the unit. This procedure only requires a few minutes
Items to be inspected include:

a Pump packing gland.

1) Seal water pressure

2) Seal leakage (too much, sufficient or too little
leakage)

3) Seal leakage dram flowing clear

4) Mechanical seal leakage (if equipped)
b- Pump operating pressures.

1) Pump suction (Pressure Vacuum)

A higher vacuum than normal may indicate a partial-
ly plugged or restncted suction line. A lower vacu-
um may indicate a higher suction water level or a
worn pump impeller or wearing rings.

Water Hammer The ^nund ,tke someone hammering on a pipe that occurs when a valve is opened or closed very rapidly. When a
valve position is changed quickly, the wati.. pressure in a pipe will increase and decrease back and forth very quickly. This rise and fall
in pressures can do serious damage to the system.

Maintenance 285

2) Pump discharge pressure

System pressure Is indicated by the pump dis-
charge pressure. Lower than normal discharge
pressures can be caused by:

a) Worn impeller or wearing rings in the pump;

b) A different point of discharge can change dis-
charge pressure conditions;

c) A broken discharge pipe can change the dis-
charge head.

NOTE. To determine the maximum head a centrifugal pump
can c^'^velop, slowly close the discharge valve at the
pump. Read the pressure gage between the pump
ana the discharge valve when the valve is fully
closed. This is the maximum pressure the pump is
capable of developing. Do not operate the pump
longer than a few minutes with the discharge valve
closed completely because the energy from the
pump is converted ;o heat and water in the pump can
become hot enough to damage the pump.

c. Motor temperature and pump bearing temperature.

If motor or bearings are too hot to touch, further
checking is necessary to determine if a problem has
developed or if the temperature is normal. High tem-
peratures may be measured with a thermometer.

d Unusual noises, viDrations, or conditions about the
equipment.

If any of the above items indicate a change from the
pump*s previous operating condition, additional ser-
vice or maintenance may be required during shut-
down.

3. Actuate stop switch for pump motor and lock out switch.
If possible use switch next to equipment so that you may
observe the equipment stop. Observe the following items:

a. Check valve closes and seats.

Valve should not slam shut, or discharge piping will
jump or move in their supports. There should not be
any leakage around the check valve shaft. If check
valve is operated automatically, it should close
smoothly and firmly to the fully closed position.

ERIC

NOTE If the pump is not equipped with a check valve,
close discharge valve before stopping pump.

b Motor and pump should wind down slowly and not
make sudden stops or noises during shutdown.

c After equipment has completely stopped, pump shaft
and motor should not start back-spinning. If back-
spinning IS observed in a pump with a check valve or
foot valve, close the pump discharge valve SLOWLY'
Be extra careful if the.^ is a plug valve on a line with a
high head because when the discharge valve is part
way closed, the plug valve could slam closed and
damage the pump or piping.

4. Go to power control panel containing the pump motor
starters just shut down and OPEN motor breaker switch,
lock O'jt, and tag.

5. Retum to pump and close:
a. Discharge valve,

b Suction valve,

c. Seal water supply valve, and

d Pump volute bleed line (if so equipped).

6. If required, close and open appropnate valves along
piping system through which pump was discharging.

Starting Procedures

This section contains a typical sequence of procedures to
follow to start a centrifugal pump.

1 Check motor control panel for lock and tags. Examine
tags to be sure that NO item is preventing startup of
equipment.

2. Inspect equipment

a. Be sure stop switch is locked out at equipment loca-
tion.

b. Guards over moving parts must be in place.

c. Clean-out on pump volute and dram plugs shoulc* '^e
installed and secure.

d. Valves should be in closed position.

e. Pump shaft must rotate freely.

f Pump motor should be clean and air vents clear.

g Pump, motor, and auxiliary equipment lubncant level
must be at proper elevations.

h. Determine if any special considerations or precautions
are to be taken dunng startup.

3. Follow pump discharge piping route. Be sure all valves
are in the proper position and that the pump flow will
discharge where intended.

4. Retum to motor control panel.

a. Remove tag.

b. Remove padlock.

c. Close motor main breaker.

d. Place selector switch to manual (if you have automatic
equipment).

3'Ju

286 Water Treatment

5. Return to pump equipment

a. Open seal water supply line to packing gland. Be sure
seal water supply pressure is adequate

b. Open pump suction valve slowly.

c Bleed air out of top of pump volute in order to pnme
pump Some pumps are equipped with air relief valves
or bleed lines back to the we! well for this purpose.

d. When pump is primed, slowly open pump discharge
valve and recheck prime of pum.p Be su^'e no air is
escaping from volute.

e. Unlock stop switch and actuate start switch. Pump
should start

6. Inspect equipment.

a. Motor should come up to speed promptly. If ammeter
IS available, test for excessive draw of power (amps)
dunng startup and normal operation. Most Ihree-
phase induction motors used in water treatment plants
will draw 5 to 7 times their normal running current
during the brief penod when they are coming up to
soeed.

b No unusal noise or vibrations should be observed
dunng startup

c. Check valve should be open and no chatter or pulsa-
tion should be observed.

d. Pump suction and discharge pressure readings should
be within normal operating range for this pump.

e Packing gland leakage should be normal.

f. If a fiow meter is on the pump discharge, record pump
output

7 If the unit IS operating properly, return to the motor
control panel and place the motor mode of operation
selector tn the prope' operating position (manual-auto-
off).

8. The pump and auxiliary equipment should be inspected
routinely after the pump has been placed back into
service.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 325.

18,24G What should be done before stopping an operating
pump?

18.24H What could cause a pump shaft or motor to spin
backwards?

18.241 Why should the position (open or closed) of all
valves be checked before starting a pump*?

18.2451 Positive Displacement Pumps. Steps for starting
and stopping positive displacement pumps are outlined m
this section. There are two basic differences in the operation
of positive displacement pumps as compared with centrifu-
gal pumps. Centrifugal pumps (due to their design) will
permit an operator error, jut a positive displacement pump
will not and someone will have to pay for correcting the
damages.

ERIC

Important rules for operating ucsitive displacement
pumps include

VAUVg,g4PeglAtLVAC7l4CUAg6gyAl\/e.

'i Excessive pressure could rupture the equipment and
possibly seriously injure or kill someone ne?r*by.

2 Positive displacement pumps are used to pump solids
(sludge) and meter chemicals. Certain precautions must
be taken to prevent .njury or damage. If the valves on
both ends of a sludge line are closed tightly, the I'ne
becomes a closed vessel Gas from decomposition of the
sludge can build up and rupture pipes or valves.

3. Positive displacement pumps also are used to meter and
pump chemicals, oare must be exercised to avoid venting
chemicals to the atmosphere.

4. Never operate a positive displacempnt pump when it is
dry or empty, especially the progressive-cavity types that
use rubber stators. A small amount of liquid is needed for
lubncation in the pump cavity between the rotor and the
stator.

In addition to NEVER closin/ a discharge valve on an
operating positive displacement^pump, the only other differ-
ence (when compared with a centrifugal pump) may be that
the positive dibplacement pump system may or may not
have a check valve m the discharge piping after the pump
Installation of a check valve depends upon the designer and
the material being pumped.

Other than the specific differences mentioned in this
section, the starting and stopping procedures for positive
displacement pumps are similar to the procedures for centn-
fugat pumps.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 326.

18 24J What IS the most important rule regarding the
operation of positive displacement pumps?

18 24K What could happen if a positive displacement pump
IS started against a closed discharge valve?

18 24L Why should both ends of a sludge line never be
closed tighf?

Please answer the discussion and review questions be-
fore continuing with Lesson 4.

311/

Maintenance 287

DISCUSSION AND REVIEW QUESTIONS

Chapter 18. MAINTENANCE

(Lesson 3 of 5 Lessons)

Write your answers to these questions in your notebook
before continuing. The question numbering continues from
Lesson 2

1 8 When two or more pumps of the same size are installed,
why should they be ojierated alternately'?

19 vv^.!?t should be checked if pump bearings are running
hof?

20. What happens when the packing is too tight on a
reciprocating pump'?

21 Why should adjustments in control valves for recipro-
cating pumps be made when the pump is shut down'?

22. Why would you use a stethoscope to check an electric
motor'?

23. How would you determine if a motor is running unusual-
ly hof?

24 How would you clean belts on a belt drive?

25. Why should you never replace only one bt ' on a
multiple-dnve unif?

26. What do rubber wearings near a belt drive indicate'?

27. How can you dete^'mme if a chain in a chain-drive unit
has the proper slack'?

28. What happens when couplings are not in proper align-
ment?

29 How can you determine if a new pump will turn in the
direction intended'?

30. When shutting down a pump for a long pe..od, what
precautions should be taken with the motor disconnect
switch'?

31 How can you determine if a new pump is delivering
design flows and pressures'?

CHAPTER 18. MAINTENANCE

(Lesson 4 of 5 Lessons)

18.25 Compressors

Compressors (Fig 18.31) are commonly used in the
operation and maintenance of water treatment plants They
are used to activate and control pump control systems
(bubblers), valve operators, and water pressure systems
They are also used to operate portable pneumatic tools,
such as jack hammers, compactors, air drills, sand blasters,
tapping machines, and air pumps.

A compressor is a device used to increase the pressure cf
air or gas. They can be of a very simple diaphragm or
bellows type such as are found in aquanum pumps, or
extremely complex rotary, piston, or sliding vane type com-
pressors. A compressor usually has a suction pipe with a
filter and a discharge pipe which goes tq an air receiver or
storage tank. The compressed air or gas \ then used from
the air receiver.

ERIC

Due to the complexity of compressors, the water treat-
ment plant operator usually will not be repairing them. You
will, however, be required to maintain these compressors.
With proper maintenance a compressor should give years of
trouble-free service.

The first step for compressor maintenance, and this
pertains to any mechanical equipment, is to get the manu-
facturer's istruction book and read it completely. Each
compressor is different and the particular manufacturer will
provide its recommended maintenance schedules and pro-
cedures. Some of the maintenance procedures are dis-
cussed in the following paragraphs.

1. Inspect the suction filter of the compressor regularly.
The frequency of cleaning depends upon the use of the
compressor and the atmosphere around it. Under nor-
mal operations the filter should be inspected at least

'JC3

288 Water Treatment

Fig. 18.31 Two-stage piston compressor

(Courtesy Worthington Corporation)

monthly and cleaned or replaced every three to six
months Inspect and replace the filter more frequently in
areas with excavation and dust. When breaking up
concrete, inspect the filters daily.

There are several types of filters, such as paper, cloth,
vyire screen, oil bath, and others. The impregnated
paper filters must be replaced when dirty. The cloth-
type filters can be washed with soap and water, dried
and reinstalled. If a cloth-type filter Is used, it is recom-
mended that a spare be kept so one can be cleaned
while the other is being used. The wire mesh and oil-
bath type filters can be cleaned with a standard solvent,
reoiled or oil bath filled and used again. Never operate a
compressor without the suction filter because dirt and
foreign materials will collect on the rotors, pistons, or
blades and cause excessive wear.

2. Lubrication. Improper or lack of lubrication is probably
the biggest cause of compressor failures. Most com-
pressors require oiling of the bearings. They can have
crank case reservoirs, oil cups, grease fittings, a pres-
sure systeni or separate pump Whatever type. It must
be Inspected daily. Examine the reservoir dip stick or
sight glass. Make sure that dnp-feed oilers are dripping
at the proper rate, force fred oilers have the proper

ERLC

pressure, and grease fittings are greased at the proper
interval. Compressors use a certain amount of oil in
their operation and special attention is needed to keep
the reservoirs full. Care also must be used to not overfill
the crankcase. On some compressors it is possible for
the oil to get into the compression side and lock up the
compressor, or damage It. Remember!

A UiaUlP CANNOT SB COIAPQt^^SV.

When air or gas are compressed, they give off heat and
the compressor becomes very hot. This tends to break
down oil faster, so most compressor manufacturers
have special oils recommended for their particular com-
pressor. Also, due to the heat and contamination, it is
necessary to change oil quite frequently. Compressor
oil should be changed at least every three months,
unless manufacturer states differently. If there are filters
m the oil system, these also should be changed.

3. Cylinder or casing fins should be cleaned weekly with
compressed air or vacuumed off. The fins must be clean
to insure proper cooling of the compressor.

4. Unloader. Many compressors have unloaders that allow
the compressor to start under a no-load condition.
These can be inspected by observing the compressor.
When the compressor starts, it should come up to
speed and the unloader will change, starting the com-
pression cycle. This can usually be heard by a change in
sound. When it stops, you can hear a small pop and
hear the air bleed off the cylinders. If the unloader is not
working properly, the compressor will stall when start-
ing, not start, or if belt-driven, burn off the belts.

Maintenance 289

5 Test the safety valves weekly The pop off or safety
valves are located on the air receiver or storage tank.
They prevent the pressu^'e from building up above a
specified pressure by opening and venting to thp atmos-
phere, in gas compressors, they vent to the suction side
of the compressor. Some compressors have high pres-
sure cut-off switches, low oil pressure switches, and
high temperature cut-off switches. These switches have
pre-set cut-off settings and must not be changed with-
out proper authorization If for any reason any of the
safety switches are not functioning properly, the prob-
lem must be corrected before starting the compressor
again The safety switch settings should be recorded
and the results kept ir the equipment file

6. Dram the condensate (condensed water) from the air
receiver daily. Due to temperature changes, the air
receiver will fill with condensate. Each day the conden-
sate should be drained from the bottom of the tank
There is usually a small valve at the bottom of the air
receiver for this purpose. Some air receivers are
equipped with automatic dram valves These must be
inspected periodically to insure they are operating satis-
factorily

7 Inspect belt tension on compressors Usually you
should be able to press the belt down with hand
pressure approximately three-fourths of an inch. This is
done at the center between the two pulleys MAKE
SURE COMPRESSOR IS LUCKED OFF BEFORE MAK-
ING THIS TEST. Do not over-tighten belts because it will
cause overheating and excessive wear on bearings and
motor Overloading

8 Examine operating controls Make sure the compressor
IS starting and stopping at the proper settings If it is a
dual installation, make sure they are alternating if so
designed, inspect gage for accuracy Compare readings
with recorded startup values or other known, accurate
readings

9. Many portable compressors are equipped with tool
oilers on the receivers. These are used for mixing a
small quantity of oil with the compressed air for lubrica-
tion of the tools being used These are located on the
discharge side of the air receiver. They have a reservoir
which must be filled with rock drill oil.

10 All compressors should be thoroughly cleaned at least
monthly Dirt, oil, grease, and other material must be
thoroughly cleaned off the compressor and surrounding
area Compressors have a tendency to lose oil around
piping, fittings and shafts; thus constant cleaning is
required by the maintenance operator to insure proper
and safe operation.

QUESTIONS

Write your answers m a notebook and then compare your
answers with those on page 326.

18 25A List some of the uses of a compressor in connec-
tion with operation and maintenance of a water
treatment plant.

1 8.25B How often should the suction filter of a compressor
be cleaned''

18.26C How often should compressor oil be changed*?

18 25D How often should the condensate from the air
receiver be drained*?

18 25E What must be done before testmg belt tension on
compressors with your hands'?

18.26 Valves^^

18.260 use of Valves

Valves are the controlling devices placed m piping sys-
tems to stop, regu'ate, ^.^teck, divert, or otherv^ise modify the
flow of liquids or gases There are specific valves that are
more suitable for certain ;obs than others. The five most
common valves that you will find m a water treatment facility
are discussed in this section

18.261 Gate Valves (Figures 18.32 and 18 33)

The basic parts of a gate valve are- the operator (handle),
the shaft packing assembly, the bonnet, the valve body with
seats, the stem, and the disc Gate valves cor.^e a large
number of sizes, but the principle of operation is quite
similar for all sizes. One could associate the action of a gate
valve to that of a guillotine having a screw shaft instead of
the rope The valve disc is raised or lowered by a threaded
shaft and is guided on each side to ensure that it will not
hang up m the operation. The disc is screwed down until it
wedges itself between two machined valve seats This
makes a leak-proof seat on both sides of the disc The discs
are replaceable Some gate valves have discs with wedges
inside As more force is applied to the screwed stem, the
wedges force the discs into tighter contact with the valve
seats

Gate valves are either of the rising (Figure 18 32) or non-
rismg stem (Figure 1 8.33) type The rising stem has compan-
ion threads m the valve bonnet. As the valve is opened, the
stem IS threaded out, lifting the wedged disc In the non-
rising type, the stem is held in place in the bonnet by a collar.
The stem is threaded with companion threads in the wedged
disc As the valve opens, the disc rises on the stem
Consequently, the hand wheel stays on the same plane.

Gate valves are not commonly used to control flows With
the valve partially open, the water velocity is increased
through the valve and minute particles transported in the
water can cause undue seat wear. However, the vee-ported
gate valve can be used m controlling flows. As the valve is
opened, the vee is widened to allow more flow Because of
the valve design, little damage is done to the valve seats m
the vee-ported type of gate valve.

Suggested operation and maintenance procedures are
listed below

1 Open valve fully. When at stop, reverse and close valve
one-half turn.

2 Operate all large valves at least yearly to insure proper
operation

3. Inspect valve stem packing for leaks Tighten as needed

4. If the valve has a rising stem, keep stem threads clean
and lubricated

5. Close valves slowly in pressure lines to prevent water
hammer

17 For additional information on valves, see WATER DISTRIBUTION SYSTEM OPERATION AND MAINTENANCE, Chapter 3, Distribution
System Facilities, Section 3.670, "Valves,'' in this series of manuals.

310

290 Water Treatment

Ftg. 18.32 Rising stem gate valve

(Permission of Stockham Valves & Frttings. Copyright. 1976)

Fig. 18.33 Non-nsing stem gate valve

(Permission of Stockham Valves & Fittmgs. Copyright. 1976)

ERIC 311

Maintenance 291

6. If a valve wiH not close by using the normal operator,
check for the cause. Using a "cheater" (bar-pipe wrench)
Will only aggravate your problem.

18.262 Maintenance of Gate Valves

Paragraph 12: Gate Valves

The most common maintenance required by gate valves is
Oiling, tightening, or replacing the stem stuffing box packing.

Frequency
of
Service

A 1. REPLACE PACKING. Modern gate valves
can be repacked without removing tnem
from service. Before repacking, open valve
wide. This prevents excessive leakage
when the packing or the entire stuffing box
IS removed. It draws the stem collar tightly
against the bonnet on a non-rising stem
valve, and tightly against the bonnet bush-
ing on a rising stem valve.

a. Stuffing box. Remove all oij packing
from stuffing box with a packing hook or
a rattail fih with bent end. Clean valve
stem of all adhering particles and polish it
with fine emery cloth. After polishing re-
move the fine gnt with a clean cloth to
which a few drops of oil have been
added.

b. Insert packing Insert new split-ring pack-
ing in stuffing box and tamo it into place
with packing gland. Stagger ring splits.
After stuffing box is filled, place a few
drops of oil on stem, assemble gland,
and tighten it down on packing

S 2 OPERATE VALVE. Operate inactive gate
valves to prevent sticking.

A 3 LUBRICATE GEARING. Lubricate gate
valves as recommended by manufacturer.
Lubricate thoroughly any gearing in large
gate valves. Wash open gears with solvent
and lubricate with grease.

S 4 LUBRICATE RISING-STEM THREADS.

Clean threads on rising-slem gate valves
and lubncate with grease

A 5 LUBRICATE BURIED VALVES. If a buried
valve works hard, lubricate it by pouring oil
down through a pipe which is bent at the
end to permit oiling the packing follower
below the N/alve nut

A 6 REFACE LEAKY GATE VALVE SEATS If
gate valve seats leak, reface them immedi-
ately, using the method discussed below. A
solid wedge disc valve is used for illustra-
tion, but the general method also applies to
other types of reparable gate valves. Pro-
ceed as follows:

a Remove bonnet and clean and examine
disc and body thoroughly. Carefully de-
termine extent of damage to body rings

18 Prussian Blue. A blue paste or hqwd (often on a paper like carbon
seats fit properly.

and disc If corrosion has caused exces-
sive pitting or eating away of metal, as in
guide ribs in body, repairs may be im-
practical.

b Check and service all parts of valve com-
pletely. Remove stem from bonnet and
examine it for sconng and pitting where
packing makes contact. Polish lightly
with fine emery cloth to put stem in good
condition. Use soft jaws if stem is put in
vise

c. Remove all old packing and clean out
stuffing box Clean ail dirt, scale, and
corrosion from inside of valve bonnet
and other parts.

d Do not salvage an old gasket. Remove it
completely and replace with one of prop-
er quality and size.

e. After cleaning and examining all parts,
determine .nether valve can be repaired
by ren^oving cuts from disc and body
seat faces or by replacement of body
S'iats. If repair can be made, set disc in
vise with face leveled, wrap fine emery
cloth around a flat tool, and rub or lap off
entire bearing suriace on both sides to a
smooth, even finish. Remove as little
metal as possible.

f Repair cuts and scratches on body rings,
lapping with an emery block small
enough to permit convenient rubbing all
around rings. Work carefully to avoid
removing so much metal that disc will
seat too low. When seating surfaces of
disc and seat rings are properly lapped
in, coat faces of disc with PRUSSIAN
BLUE^^ and drop disc in body to check
contact. Wlien good, continuous contact
IS obtained, the valve is tight and ready
for assembly. Insert stem in bonnet, in-
stall new packing, assemble other parts,
attach disc to stem, and place assembly
in body Raise stem to prevent contact
with seats so bonnet can be properly
seated on body before tightening the
joint.

g. Test repaired valve before putting it back
in line to ensure that repairs have been
properly made.

h. If leaky gate valve seats cannot be re-
faced, remove and replace seat rings
with a power lathe Chuck up body with
rings vertical to lathe and use a strong
steel bar across ring lugs to unscrew
them. They can be removed by hand with
a diamond point chisel if care is taken to
avoid damaging threads. Dnve new rings
home tightly. Use a wrench on a steel oar
ac.oss lugs when putting in rings by
hand. ^Jways coat threads with a good
lubncant before putting threads into the
valve body. This helps to make the

used to show contact area Used to determine if gate valve

292 Water Treatment

Frequency
of
Service

threads easier to remove the next time
the seats have to be replaced Lap in
rings to fit disc perfectly.

18.262 Globe Valves (Fig. 18.34)

The globe valve seating configuration is quite different
from the gate vatve Globe valves use a circular disc to maKe
a flat surface contact with a ground-fitted valve seat. This is
Similar to placing your thumb over the end of a tube. The
parts of the valve are similar m name and function to the gate
valve. They can be of the rising or non-nsing stem type

What IS unique about the globe valve is its internal design
(Figure 18.34). This design enables the valve to be used in a
controlling mode The valve seats are not subject to exces-
sive wear when partially opened like the gate valve. After
extended use. the valve may not have a positive shutoff but
It will still be effective in throttling flows. Procedures for
operating and maintaining globe valves are similar to the
procedures outlined for gate valves in Section 18 262

18.264 Eccentric Valves (Figs 18.35 and 18.36)

The eccentric valve has many desirable features These
features include allowance for high flow capacity, quarter
turn operation, no lubrication, excellent resistance to wear,
and good throttling characteristics. The eccentric vaive uses
a cam shaped plug to match an eccentric valve seat. As the
valve IS closed, the plug throttles the flow yet maintains a
smooth flow rate The plug does not come into contact with
the valve seat until it is in the closed position.

Because the plug has a resilient coating, it insures a leak-
tight seal at the valve seats The Buna-N, neoprene. or viton
plug coating is a very wear resistant compound and can
function well under a wide temperature range. This valve is
excellent for controlling the flows of sfurnes and sludges
found in water treatment facilities

18.265 Butterfly Valves (Fig. 18.37)

The butterfly valve is used primarily as a control valve. The
flow Characteristics allow the water to move in straight lines
w'th little turbulence in the area of the valve disc (butterfly;.
Complete flow shutoff can be accomplished but the PSI
rating is relatively low in comparison to eccentric or gate
valves

The butterfly valve uses a machined disc that can be
opened to 90 degrees to allow full flow through the valve.
Quarter turn operation moves the valve from the closed' to
open' position The disc is mounted on a shaft eccentric that
allows the disc to come into its seat with minimum seating
torque and scuffing of the rubber seat There is no contact
between the disc and the seat until the last few degrees of
valve closure

A resilient rubber is used as the seat and is of a continu-
ous form that ic not interrupted Dy a shaft connection. Wear
resistance characteristics are good when used m slurry and
sludge applications.

When the valve is closed, the disc is forced against the
.jbber seat Wedges with jacking screws compress the
rubber seat via a jack nng. The rubber seat then w^nforms to
the entire disc circumference. The rubber can be readily
replaced when necessary without complete valve disman-
tling Large valves do not need to be removed from the line
for seat repacement.

IDENTIFICATION PUTE

DISC lOCK NUT

Fig. 18.34 Globe valve

(Permission of Stockham Valves and "ittings)

ER?C 3IJ

Maintenance 293

ECCENTRIC ACTION

The DeZurik design matches a single-faced
eccentric or cam-shaped plug with an ec-
centric raised body seat. With rotary
motion only, the plug advances against
the seat as It closes. Here's how It works:

OPEN— The plug Is out of the flow path.
There Is no bonnet or other cavity to fill
with slurry material. Flow is straight-
through with minimum pressure drop.

CLOSING— At any position between open
and closed, the eccentric plug still has not
touched the seat. There Is no friction to
cause wear or binding. Flow Is still smooth
and straight. Throttling action Is excellent
on all types of services from slurries to gas.

CLOSED— The eccentric plug makes con-
tact with the eccentric seat only in the
fully closed position. Action Is easy, with-
out binding or scraping. There is no con-
tinual seat wear. The plug Is moved firmly
into the seat to provide a positive, drip-
tight, long-lasting seal.

Fig, 18.35 How eccentric valves work

(Permission of DeZurik Corporation. Sartell. Minnesota)

ERIC

31 'I

294 Water Treatment

Maintenance 295

Fig. 18 37 Butterfly valve

(Permi5S»on ol Amencan-Dfefling Valvo. Birmtngham. Alabama)

316

296 Water Treatment

18.266 Check Valves (Fig. 18.38)

The term check valve' describes its function. A check
valve allows water to flow in one direction only. If the water
attempts to flow in the opposite direction, an internal mecha-
nism closes the valve and "checks" the flov^. Three types of
check mechanisms may be used — the swing check, the
water check, or the lift check. In the swing check, a move?
ble disc rests at a right angle to the flow and seats against a
ground seat. The moveable disc is called the clapper. The
clapper can be one of three types: gravity operated, lever
and weight operated, or lever and spnng operated. In many
installations the water being pumped must be delivered at a
desired flow rate and pressure. A clapper with an external
means of adjusting the opening in the check valve may be
necessary to produce desired flows and pressures. By
positioning the weight on the lever or adiusting the spring
tension, a check valve can be made to operate either
partially or fully open at vanous pressures and flows. The
spring or counter weight also ensures that the check valve
closes at "no flow." This is very helpful if the valve is not in a
position that will enable gravity alone to operate the clapper
The gravity-operated clapper does not have an externa!
adjustment and relies on the weight of the clapper to close
the valve at ' no flow" conditions.

Most swing check valves provide for full opening, that is,
the clapper can move up into the bonnet and thus be
c "oletely out of the flow. Head loss in swing check valves
ma;, je relatively high and this factor must be considered in
selecting the device for a particular application. This type of
check valve is quite common in pump installations and often

has a dampening feature to cushion the clos-ng of the
clapper.

The wafer check has a circular disc that hinges in the
center (diameter) of the disc Water passing through col-
lapses the disc and the stoppage of flow allows the disc to
return to its circular form Because the valve has a tendency
to be fouled up by stringy material, it is not commonly used
in handling raw water. Wafer check valves a''e very effective
when used with clean water.

The lift check uses a vertical lift disc or ball. When there is
flow, the disc or ball is lifted from its ground seat and fluid
passes through the valve As flow stops, the check realigns
itself with Its seat and checks or prevents water backflow.
The moveable portion can be a spring or gravity return.

The foot valves used in pump suctions are nearly always
of the vertical lift disc design. A check valve of this type is
usually applied to handle clean water.

Backflow prevention by check valves is essential in many
applications to:

1 Prevent pumps from reversing when power is removed,

2. Protect water systems from being cross-connected,

3 Aid in pump operation as a dampener, and

4. Ensure "full pipe" operation (pipe is full of water).

Table 18.4 provides a comparison of vanous types of
check valves with features of these valves. Figures 18.39
through 18.45 prov drawings and photographs of the
different types of ch ^k valves listed in Table 18.4.

ERLC

Tight closing assured
since clapper arm shaft
is set slightly back of
vertical seat face.

Bronze clapper arm shaft
can be extended through
bod*/ when lever with
weight or spring i
quired.

Fully revolving disc^
seats in different posi-
tion on seat ring face
and distributes wear uni-
formly over the entire
seating fare.

Bronze seat ring is
screwed In body and
made with lugs and can '
be replaced with body
in line. It can be furn-
ished with a resilient in-
sert for bottle«tight ser-
vice on gas or air.

Bronze bushed ductile
iron clapper arm for
added strength and im-
pact resistance.

Body design permits re*
moval of clapper arm
assembly through bon-
net opening.

Bronze or alloy disc ring
is securely peened into
machined dove-tai led
groove.

Fig. 18.38 Check valve

(Permssion of Amencan-Dariing Valve. Birmingham, Alabama)

Vertical seating surfaces
provide sensitive seating
action.

31V

Maintenance 297

TABLE 1 8.4 COMPARISON OF FEATURES OF
DIFFERENT TYPES OF CHECK VALVES^

Lowest initital cost
Shiortest laying lengrhi
Highest hiead loss (see hiead loss curves)
Resilient seat (optional)
For waste and raw sewage
Clean water only
Cushiion closing
Silent closing (positively silent)
Free open - Free close
Control open or close or bothi (optional)
Vertical installation flow up or down
Can be rubber lined
Disc position indicator
Buried service
Outside lever
Surge pressure control
Reverse flow
Up to 600# class
Uptol500#class

Lowest hiead loss (see hiead loss curves)
Up to 2500# class
Control open and close standard
Shut off valve
Throttling valve

Vertical installation flow up only
Electric motor operated
Remote control

Control closure upon power failure
Resilient seat standard
Velocities in excess of 1 5 FPS
Velocities up to 5 FPS
Velocities up tolOFPS

a Permission of APCO/Valve and Primer Corporation.

er|c

318

298 Water Treatment

Maintenance 299

300 Water Treatment

Maintenance 301

Fig, 18,42 Slanting disc check valves (pivot off center)

(pormission of APCO/Valve and Prtmer CorporaJion)

ERJC 3H2

302 Water Treatment

Maintenance 303

304 Water Treatment

Maintenance 305

18.267 Maintenance of Check Valves
Paragraph 13: Check Valves

Frequency
of

Service

A 1 INSPECT DISC FACING Open valves to
observe condition of facing on swing check
valves equipped with leather or rubber
seats on disc. If metal seat ring is scarred,
dress it with a fine file and lap with fine
emery paper wrapped around a flat tool.

A 2. CHECK PIN WEAR. Check pin wear on
balanced disc check valve, sincG disc must
be accurately positioned in seat to prevent
leakage

18,268 Automatic Valves

Water treatment plants usually have a number of auto-
matically operated valves. The simplest type Is either open
or closed and is not required to operate in an intermediate
position. Frequently these valves are similar to gate valves
that have had their threaded stems and handwheels re-
placed by a smooth shaft and hydraulic piston. Maintenance
on these v^*' '-;s Is essentially the same as for gate valves.

Other automatically operated valves are used to control
flow in water treatment plants and are usually located at
some point between tight shut and wide open. These are
commonly called modulating valves. A buttp fly valve with a
hydraulic cylinder operator can be use^ for this type of
service.

The diaphragm-operated globe valve (Figure 18.46) is also
used for modulating service These valves can be equipped
with pilot control devices to control pressure, flow, or level
either singly or in combination. Maintenance on these valves
consists of the following:

1. Periodically clean any strainers in the pilot control sys-
tem Scheduling should be adjusted to accommodate the
rate at which the strainer collects foreign material.

2. Check the operation of the valve to see ihat the controls
are. in fact, correctly positioning the valve to accomplish
the job.

3. If the valve is used in an application where it seldom or
never is wide open, it should periodically be exercised
manually to cycle from tight shut to wide open. This is to
insure that there is no buildup on the stem that could jam
the valve. These valves can be opened wide by drawing
all the pressure from the cover chamber. If water does
not stop flowing out of the cover chamber, when the valve
IS wide open, it is an indication that the diaphragm Is
leaking and should be replaced.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 326.

18.26A What IS the purpose of valves'?

18 26B List six common types of vah'^s found in water
treatment facilities

18 26C What is the purpose of a check valve?

18.26D Why is backflow prevention by check valves essen-
tial in many applications?

18 26E What maintenance is required by gate valves'?

Please answer the discussion and review questions be-
fore continuing with Lesson 5.

DISCUSSION AND REVIEW QUESTIONS

Chapter 18. MAINTENANCE

(Lesson 4 of 5 Lessons)

Write your answers to these questions in your notebook
before continuing. The question numbering continues from
Lesson 3.

32. What are the uses of a compressor?

33. What Items should be maintained on a compressor*?

34 Why should inactive gate valves be operated periodic-
ally?

35. What factors can cause wear on gate valve seats?

ER?C

32S

306 Water Treatment

ERIC

Fig. 18.46 Diaphragm operated globe valve

(Permission of CLA-VAL Co )

Maintenance 307

CHAPTER 18. MAINTENANCE

(Lesson 5 of 5 Lessons)

18.3 INTERNAL COMBUSTION ENGINES
18.30 Gasoline Englnes^^

18.300 Need to Maintain Gasoline Engines

In the water treatment departments of all cities there is
occasion to use gasoline-powered engines that drive
pumps, generators, tractors, and vehicles. Although we all
drive automobiles that are powered by internal combustion
engines, are you aware of the fundamentals'?

Very 'ew operators actually do the repair of gasoline-
powered engines. Although you may not be able to perform
the duties of an engine mechanic, there are a number of
steps you can take to ensure that your particular engine is
well maintained.

At the end of this section you will have an adequate
knowledge of how a gasoline engine operates in order to
maintain it so as to provide many hours at optimum per-
formance.

18.301 Maintenance

In order to have an engine that will provide you with many
hours of trouble-free operation, it must be well cared for
PLEASE REFER TO THE OWNER/OPERATOR MANUAL
FOR YOUR PARTICULAR ENGINE. Typical maintenance
procedures are as follows:

1 Change engine oil regularly every 25 hours,

2 Clean carburetor air filter every 25 hours;

3 Blow dust and chaff from louvered engine vanes regu-
larly;

4 Clean carbureto'' fuel filter/screen eveiy 100 hours;

5 Lubncate generator and/or starter motor as recommend-
ed, every 100 hours;

6. Lubricate throttle linkage every 100 hours.

7. Clean, gap, or rer/!3C0 spark plug every 100 hours; and

8. Remove carbon deposits from top of piston and valves
every )0 to 3C0 hours.

18.302 Starting Problems

Listed below are some items to check if you have prob-
lems starting a gasoline engine

1 . No fuel in tank, valve closed

2 Carburetor not choked

3 Water or dirt in fuel lines of carburetor

4 Carburetor flooded

5 Low compression

6 Loose spark plug, and
7. No spark at plug

a Dirty and improper/gapped plug

b Broken or wet ignition cables

c. Greaker points not opening or closing, and

d Magneto grounded

18.303 Running Problems

Check the following items a gasoline, engine does not
run properly

1 Engine misses

a Faulty spark plug/gappmg

b Weak ignition spark

c Loose ignition cable

d Worn breaker points

e Water in fuel

f Poor compression

2 Engine surges

a Carburetor flooding

b Governor spring connected improperly

For additional information on y^soline engines, see INDUSTRIAL WASTE TREATMENT, Chapter 7, Support Systems, Section 74,
"Gasoline Engines," in this series of manuals.

308 Water Treatment

3 Engine stops
a Fuel tank empty

b. Vapor lock
c Tank air vent plugged

4 Engjne overheats
a Low crankcase oil
b igmtjon fming wrong
c Engine overloaded

d Restricted air circulation/high ambient temperature
e. Poor grade of gasoline

5. Engine knocks
a Poor grade of gasoline
b Engine under heavy load at low speed

c. Carbon deposits m cylinder head

d. Spark advanced too far

e. Loose connecting rod bearing
f Worn or loose piston pin

6. Engine backfires through carburetor
a Water or dirt n fuel
b Cold engine
c Poor grade of gasoline
d. Sticking mlet valves
e Spark plug heat range too hot

QUESTIONS

Wnte your answers m a notebook and then compare your
a.iswers with those on page 326

18.30A List some possible uses of gasoline engines m
water treatment plants.

18.30B What items would you check if you had problems
starting a gasoline engine?

18.30C What Items could cc jse a gasoline engine to not
run properly?

18,304 How to Start a Gasoline Engine

Because of the wide variety of uses for gasoline-powered
engines, no one starting sequence will apply to all engines.
In general, gasoline engines can be divided into two groups.
In the first group are small engines with magneto Ignition
and recoil start. Larger engines with battery-powered igni-
tion and elertnc start are in the second group.

18.3040 imaii Engines. The procedure for starting small
engines is as follows:

1. Check fuel tank for adequate fuel;

2. Ensure fuel shut off valve fron. the tank to the carburetor
is open;

3. Disengage ignition ground f kill" switch or mechanism
that grounds the spark plug);

4. Check crankcase lubricating oil;

ERLC

5 Set throttle to start position or % full throttle;

6 Set choke lever or pull out choke on carburetor.

7 Pull recoil starter twice.

8 If engine has started, push choke to "off", and

9 If engine does not start after two pulls, disengage the
choke and try three or four more times.

If repeated efforts at starting have been unsuccessful,
remove the high tension voltage wire from the spark. Hold
the end of the wire (grasp the insulated portion, NOT the
connector) Ve inch (3 mm) from the spark plug Pull the recoil
starter. You should see a small blue spark This will indicate
that the points are opening and closing and providing
ignition voltage.

The next step is to remove the spark plug from the
cylinder head (use a ^^le inch (20.6 mm) deep socket). Check
for a carbon buildup on the electrode. A piece of carbon may
have lodgea between the center electrode and the side
electrode. Also check to see if the plug is wet with fuel or oil.
This could indicate that you have flooded the cylinder with
fuel by having the choke on too long. If there is oil residue, it
could mdlcaie worn piston rings.

Replace the spark plug with a new one if in doubt. If you
must use the one you have, clean it by buffing with a wire
brush. Check the "gap" between the center electrode and
side electrode; it should be approximately .030 inch (30
thousands of an inch or 0.76 mm).

Try staring the engine as previously described. If the
engine does not sputter or pop, close the fuel shut-off valve,
remove fuel sedimentation bowl and clean. Open fuel va've.'
Catch a small amount of fuel in the palm of your hand and
examine the fuel for grit or water. If everything looks okay,
replace sediment bowl and open fuel valve.

Try to start the engine. If you still cannot achieve ignition,
you may have other problems that will require further
checking by a small-engine mechanic Do not feel disgrun-
tled, you have checked for the most common problems.

1 8.3041 Large Engines. The procedure for starting large
engines is as follows:

1 . Check fuel tank for fuel;

2. Check crankcase for oil;

3. Check radiator for coolant (if water cooled);
4 Set throttle to V2 full position;

Maintenance 309

5 Pull out choke.

6 Turn on ignition switch and press start button.

7 After four or five engine revolutions, push m the choke,
and

8 Engine should start

After repeated tries, further invebtgation by a mechanic
may be needed

NOTE Do not crank engine with the starter lotor foi more
than one minute initially Wait two minutes and try
again for 45 seconds After three tiys. let starter
motor cool for 5 minutes before trying again This will
avo.d starter motor damage.

Preliminary checks for a large engine that won t start are
Similar to procedures for small engines

Remove spark plug wires Test each one by holding it Vs
inch (3 mm) from the spark plug or ground, and turn engine
over with the starter. You should see a small blue spark. If
you have no spark, the points are not openir or high
tension voltage is not present from the ignition coil. Check
further as needed

If spark IS present, inspect spark plugs. Clean or replace if
needed

After checking the ignition system, make sure fuel is
present at the carburetor Remove the fuel line at the
carburetor and direct it away from you and the engine
Engage starter motor for two revo jtions. Fuel should spurt
from the line if the fuel pump is working satisfactorily
Replace fuel line and wipe away any fuel that may be present
on the engine.

With fuel and ignition voltage present, it should start.
Repeat start procedure If you still cannot start the engine,
call on your mechanic to look for the problem.

NOTE' Some engines have a low oil pressure switch that
must be manually held in until sufficient oil pressure
IS present.

Do not use a starting fluid on gasoline engines unless it is
a LAST RESORT eiion to get a critical piece of equipment
running. Hard-starting engines should be inspected and
repaired by a reliable mechanic

After an engine has been starred, give it an opportunity to
warm up before applying the load. Follow manufacturer s
recommendations for the starting procedure since there is
some variation between different makes of engines

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 326.

18 30D If a gasoline eng.ne will not start and the spark plug
IS wet with fuel or oil, what has happened'^

18 30E If a gasoline engine will not start and there is an oil
residue on the spark plug, what has happened*^

18.30F After an engine has started, what should be done
before applying the load?

18.3 1 Diesel Engmes^°

18.310 How Diesel Engines Work (f\g 18 47)

Diesel engines are similar to gasoline engines and are
either two or four cycle They can be air or water cooled In
general the diesel engine is of heavier construction to
Withstand the higher pressures resulting from higher com-
pression ratios

The diesel does not use spark plugs, but instead relies on
heat generated by air compressed in the cylinder (1.000
degrees F or 540''C) to ignite the fuel mixture. The fuel is a
petroleum product that is heavier than gasoline and with a
higher flash point Gasoline cannot be used in a diesel
because it would start to burn frcm the heat generated by
compression before the piston reached the top of the stroke

A diesel has no carburetor The fuel is sprayed (injected)
into the cylinder while the cylinder is compressing air The
heat of compression ignites the fuel-air mixture and burns,
producing power similar to a gasoline engine The introduc-
tion of fuel into the cylinder must be "timed'" in the same
manner as spark to the plug m a gasoline engine Fuel is
pumped by a pumping device that is geared tc ine crank-
shaft

Diesel fuel, unlike gasoline, does not vapo 'ze readily The
fuel must be broken up in fine particles and sprayed into the
cylinder The atomization of fuel is accomplished by forcing
the fuel through a nozzle at the top of the combustion
chamber As the fuel combines with the air in the cylinder, it
becomes a combustible mixture Since the diesel engine
depends upon the heat of compressed air to ignite the fuel-
air mixture, compression pressure must be maintained
Leaking valves or piston rings (causing "blow by ) cannot be
tolerated

The fuel IS also important. The automotive-type diesel is
designed to run on a specific type or grade of fuel Trouble
can be expected if an attempt is made to use other than the
proper type

18.311 Operation

In the two-cycle engine, intake and exhaust takes place
during part of the compression and power strokes; whereas,
the four-cycle engine requires four strokes to complete the
operating cycle During one-half of the cycle, the four-stroke
acts as an air pump. The two-stroke must have a blower (air
pump) to provide the necessary air to expei the exhaust
gases and rcjharge the cylinder with fresh air

In the two-cycle, a series of ports surround the cylinder at
a point higher than the lowest position of the piston. These
are the intake ports that allow air into the cylinder The four-
cycle engine uses intake valves The incoming air forces the
expended gases out the exhaust valve, leaving the cylinder
full of clean air

As the piston starts '*s upward stroke, the exhaust valve
closes, the intake ports are sealed off by the piston, and the
air in the cylinder is compressed Shortly before the piston
reaches the top of the stroke, the required amount of fuel is
sprayed into the combustion chamber by the fuel injector.
The intense heat of compression ignites the fuel-air mixture
with the resulting combustion driving the p'Ston down on its
power stroke.

20 For additional information on diesel engines, see INDUSTRIAL WASTE TREA TMENT. Chapter 7, Support Systems. Section 7.5, "Diesel
Engines," in this series of manuals.

ERLC

'3:1

310 Water Treatment

CHARGE OF FUEL BEING INJECTED
INTO COMBUSTION CHAMBER

EXHAUST TAKING WACE AND CYLINDER ABOUT
TO BE SWEPT WITH QEAN SCAVENGING AIR

T.50I4

Power and Exhaust

ERLC

Fig. 16 47 How diessi engines work

{Source GMC Truck Overhaul Manual Series 53. permission cf General Motors Corp )

33 i

Maintenance 311

As the piston nears the bottom of the stroke, the exhaust
valve opens and the spent gases are released, assisted by
the incoming fresh air. The cycle is complete.

18.312 Fuel System (Fig. 1 8.48)

The basic parts of the fuel system are:
1 . Primary fuel filter.
2 Secondarv fuel filter.

3. Fuel injection pump, and

4. Fuel injector.

The primary filter removes all coarse particles from the
fuel and the secondary filter removes any minute particles
that remain. This ensures a clean fuel that will not clog the
injector pump or fuel injectors. The heart of the fuel system
IS the injection pump (Fig. 18.49) This pump is a gear-type
positive-displacement pump that can deliver fuel to the
injector at a very high pressure. Incorporated into the pump
IS a timing advance mechanism to advance or retard the
instant when fuel is injected into the cylinder. At high engine
speed, injection would take place sooner in the cycle. The
reverse happens for lower speeds.

A governor which uses centrifugal weights and is driven
by the pump shaft, activates a fuel control unit. When engine
speed increases, the weights are thrown toward th- ir outer
limit Geared to the assembly, the fuel control valve is
opened wider allowing more fuel to flow to the injector.

We now have higher engine speed, advanced "timing' of
injection, and the necessary fuel to sustain the faster oper-
ation. When the engine is slowed, the reverse takes place.

Fuel under pressure is fed from ths injection pump to the
appropriate fuel nozzles. When the pressure reaches ap-
proximately 3,00C psi (20,700 kPa or 207 kg/sq cm), the
valve in the injector opens allowing fuel to be Injected into
the combustion chambers As line pressure drops, the
return spring closes the nozzle valve. Fuel left in the line is
Jed back to the pump through "leak off" lines.

18.^ 13 Water-cooled Diesel Engines

Usually the larger diesel engines are of the water-cooled
type, similar to gasoline engines. In order to deliver a
sustained amount of high horsepower, an effective cooling
system is necessary to dissipate the extreme heat of com-
bustion. Because of this fact, a water-cooled engine of
comparative horsepower to the air-cooled will cost more to
manufacture, and subsequently to maintain.

18.314 Air-cooled Diesel Engines

When a lighter weight, lower horsepower, and more
ccrpoact engine is desired, the air-cooled engine will serve
your needs. You get the benefits of a diesel engine in a
smaller package.

There are some definite advantages to the diesel engine
over the gasoline engine. The initial cost is greater for the
diesel; however, the diesel:

1. Requires less maintenance because there are:

a. No plugs,

b. No contact points to pit,

c. No ignition coils or high tension wires, and

d. Fewer tune-ups.

2 Is cheaper to operate because:
a. Diesel fuel may be cheaper, and
b Better fuel efficiency

Perhaps the biggest drawbacks against Oiesel engines
are

1. Initial investment costs, and

2. Repair costs

The pros and cons must be weighed to provide you with
an engine that will fill your particular needs Whichever
engine you select, remember that a well-cared-for engine
will De there to serve you when it is needed and will provide
trouble-free operation that is essential to most users

18.315 How to Start Diesel Engines

Diesel engines vary in size and use and have varied
starting procedures. Follow manufacturer's suggested pro-
cedures for your particular engine. As with the gasoline
engine, check fuel, oil. and coolant.

To start a diesel engine, the procedures are as follows

1. Push in "stop" control,

2. Set throttle to V3 full,

3. Turn on switch and engage starter, and

4. Engine should start

Some engines have glow plugs that are energized when
the switch is placed in the start position. They preheat the
air-fuel mixture in tud cylinder to aid in starting. After the
engine is started, maintain the lower RPM's on the engine
tachometer and allow the engine to warm up. The warm-up
period IS vital to the diesel engine for eff^ient engine
performance. When operating the engine, maintain ade-
quate engine RPM's as recommended by the manufacturer.

When a diesel engine will not start after repeated tries, a
small amount of starting fluid sprayed into the air intake may
be needed to start the engine. If you use starting fluid, do not
get carried away with its use; a little goes a long way. Use it
only as a last resort or as specified by the manufacturer. If
your efforts have failed to start the engine, have a mechanic
that IS familiar with diesel engines detern.ine the cause of
the problem.

18.316 Maintenance and Troubleshooting

For detailed maintenance procedu . z for your diesel en-
gine, see your diesel manufacturer's service manual.

312 Water Treatmert

1 Nozzle Valve and Body

2 No7j2le Valve Spring

3 Leak-off Lines

4 Hydraulic Head Assembly

5 Fuel Metering Sleeve

6 Pump Plunger

7 Face Gear

8 Tappet and Roller

9 Can\

10 Governor Gears
i 1 Governor Weights

12 Governor Stop Plate

13 Fulcrum Lever

14 Stop Lever

15 Shut-off (when used)

16 Fuel Return Line

Fig. 18,48 Diesel engine fuel system

(Source Maintenance Manual, permisston of General Motors Corp )

Er|c 33 j

Maintenance 313

Fig. 16.49 Cut-away view of fuel injection pump for G-cylinder engine

(Source Maintenance Manual, permission of General Motors Corp )

TROUBLESHOOTING

Certain abnormal conditions which sometimes interfere
with satisfactory engine operation are listed in this section.

Satisfactory engine operation depends pnmanly on:

1. An adequate supply of air compressed to a sufficiently
high compression pressure.

2. The injection of the proper amount of fuel at the right
time.

Lack of power, uneven running, excessive vibration, stall-
ing at idle speed and hard starting may be caused by either
low compression, faulty injection in one or more cylinders, or
lack of sufficient air.

Since proper compression, fuel injection and the proper
amount of air are important to good engine performance,
possible problems are listed below:

1. Misfiring cylinders,

2. Improper compression pressure,

3. Engine out of fuel,

4. Proper fuel flow,

5. Excessive crankcase pressure,

6. Excessive back pressure.

7. Improper air box pressure,
8- Restricted air inlet,

9. Low oil pressure, and

10 Improper engine coolant operating temperature.

Solut.ons to these problems can be found in the operation
and maintenance instructions for the engines.

18.32 Cooling Systems (Fig. 18.50)

In an air-cooled engine, the heat generated by combustion
IS dissipated by the air circulating past the louvered cylinder
block. With a water-cooled system, the same effect is
achieved by using water. Each cylinder is surrounded with a
water jacket through which coolant circulates. This is ac-
complished by a water pump that is belt-driven from the
cankshaft. The heat transfers from the cylinder wall to the
water which, in turn, is pumped back to the radiator where
the heat is dissipated. A fan mounted on the same shaft as
the water pump ensures that a large volume of air is blown
across the radiator coils to facilitate rapid disbursbment of
heat. The cooled Wcter is then pumped back into the engine.

ERLC

334

314 Water Treatment

Engine temp^atures are regulated by transferrtng excess
heat to surrounding air.

With woftr focktts eniircly around toch cylindtr and valve, thtrt ts o great amount o/ oreo exposed to

th^ circulating coolant.

Fig, 18.50 Water cooling system

(Source Automotive Encyclopedia, permission of the Goodheart-Wiicox Co inc )

ERIC

Maintenance 315

Internal combustion engines operate more efficiently
when their temperature is maintained within narrow limits
This objective is achieved with the insertion of a thermostat
in the cooling system which is called a "temperature actu-
ated valve." When the engine is cold, the thermostat remains
closed not allowing the water to circulate back to the
radiator As the engine temperature increases to normal
operating temperature, the thermostat opens.

The radiator cap provides a function other than preventing
coolant from splashing out the filter opening The cap is
designed to seal the cooling system so that it operates
under pressure This imprc/es cooling efficiency and pre-
vents evaporation of coolant. The boiling point of water is
212 degrees F (100°C) However, for every pound of pres-
sure applied to the system, the boiling point rises 3.25
degrees F (1.8°C). If your cooling system had a 15 psi (100
kPa or 1 kg/sq cm) radiator cap and used water for coolant.
It would have a boiling point near 260 degrees F (127''C)

The use of coolant/anti-freeze provides protection against
the radiator coolant freezing and ruptunng the system and
also provides better heat transfer and heat dissipation
characteristics than water. Most of the name-orand coolants
contain rust inhibitors. Rust buildup in the cooling system
interferes with good heat transfer and the sloughing of rusi
scale can block narrow passages.

Stationary internal combustion enginej such as those
that are used to drive pumps and generators at the water
treatment plants, are often installed in a building where free
circulation of air for radiator cooling may not be possible.
For these installations, a liquid-to-liquid heat exchanger
often replaces the radiator (which is a liquid-to-air heat
exchanger). In this case, instead of the heat in the cooling
jacket water being transferred to the surrounding air, it is
transferred to anotner liquid, usually tap water. This water
may be wasted, if the engine is a standby unit and not
operated very much, or the cooling water may be recovered
in a cooling tower if the engine is in regular use.

In liquid-to-liquid heat exchanger systems a thermostati-
cally controlled valve is usually installed to regulate ♦he flow
of cooling water through the exchanger. This valve should
be checked periodically to see that it: (1) provides sufficient
water flow when the engine is running and (2) closes off tight
when ihe engine is shut down to prevent waste.

Cooling water from a heat exchanger should not be put
back mtc a potable wa^er system Any leakage in the heat
exchanger could result in engine jacket coolant contaminat-
ing the potable water supply.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 326.

18 31 A Why is gasoline not used as a fuel in diesel en-
gines?

18 31 B List the four basic parts of a diesel fuel system

18.31C What IS the purpose of the fuel injection pump?

18.32A How IS heat removed from the cylinders m a water-
cooled engine*?

1G.33 Fuel Stor..9e

18,330 Code Requirements

Storage and use of fuels for internal combustion engines
must always be in accordance with local building and firo

marshal codes In addition, the water treatment plant opera-
tor should be familiar with the particular problems associat-
ed with each of the commonly used fuels

18.331 Diesel

DIESEL This fuel comes in two grades known as #1 and
#2 Be sure to use the grade recommended by the engine
manufacturer. Be aware that the fuel grade recommendation
may vary with the season. Diesel fuel is often stored in
above ground tanks. The fuel may be kept in storage for
years without deteriorating To protect stored diesel from
water contamination, keep the storage tanks full and use
special additives.

18.332 Gasoline

GASOLINE Except for very small quantities, gasoline is
stored in underground tanks This can result in problems for
the operator If the storage tank develops a leak, either fuel
can leak out or water can leak m. Either condition is

undesirable Fuel loss ca i not only be an unwanted operat-
ing expense, but can be a danger to underground plant
piping. Gasoline detenorates rubber and if the piping is put
together with rubber gaskets or rings, the detenoration can
result in major leaks and broken couplings. Fuel loss can
best be monitored by careful accounting.

Water leakage into underground fuel tanks can result in
engine stoppages and possible damage to the engine.
Special devices are available for detecting water in gasoline
tanks and such a test should be run routinely. These devices
can be obtained by contacting your local wholesale fuel
distributor

Gasoline, unlike diesel, deteriorates in storage. For en-
gines that are in normal everyday use, this is not a problem.
However, fuel storage for standby, engine-driven equipment
requires further consideration. Engine operation and fuel
tank rej^!enishment should be scheduled so that at least one
half of the gasoline in storage is used each year. Failure to
do this can result in engines that are hard to start and in the
formation of varnish and gummy deposits that can cause
malfunctions in the parts of the fuel syste.n.

316 Water Treatment

18.333 Liquified Petroleum Gas (LPG)

LIQUIFIED PETROLEUM GAS (LPG). LPG is usually a
mixture of propane and butane. The proportions of each is
varied according to the weather temperature. The cooler the
weather, the greater the proportion of propane.

This fuel IS always stored under pressure in above-ground
tanks that are located out in the open. LPG does not
deteriorate in storage and therefore can be kept for many
years.

LPG IS heavier than air and will collect in low areas if there
IS any leakage. This poses an extremely dangerous explo-
sive threat that treatment plant operators must constantly
guard against.

18.334 Natural Gas

NATURAL GAS. This fuel is usually obtained from the
local gas company through a metered connection from their
distribution system. There is no on-site storage.

Natural gas, being lighter than air, tends to rise and
dissipate from leaks and therefore is less dangerous to
handle than LPG. Explosions can occur, however, if the
leakage is confined inside a building.

18.34 Standby Engines

Internal combustion engines must be run periodically to
ensure that, when needed, they will function properly. An
engine that is not in regular service should be started up and
test run at least once a week. The test run should be long
enough for the engine to come up to its normal operating
temperature before the engine is shut down. If at all possi-
ble, run the engine under its normal load. Just idling an
engine for 20 minutes doesn't give you much of an indication
as to whether it can handle a load. Check and make note of
the engine instruments. Look for changes that may indicate
a need for repairs. Lube oil pressure and intake manifc'^i
pressure (on spark ignition engines without supercharging
or fuel injection) are two key indicators of engine condition.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 326.

18.33A The storage and use of fuels for internal combus-
tion engines must be in accordance with what
codes?

18 33B List four types of fuels commonly used by inlernal
combus^lion engines.

18.34A Hov often should standby internal combustion en-
gines be test run when not in regular service*^

18.34B Under what conditions should standby engines be
test run*?

18.4 CHEMICAL STORAGE AND FEEDERS^'

18.40 Chemical Storage

Certain dry chemicals such as alum, ferric chloride, and
soda ash are HYGROSCOPIC.^^ These chemicals require
special considerations to protect them from moisture during
storage. Dry quicklime should be kept dry because of the

tremendous heat which is generated when it comes in
contact with water. This heat is sufficient to cause a fire

Some liquid chemicals such as sodium hydroxide (caustic
soda) should not be exposed to air because of the formation
of calDum carbonate (a solid) due to the carbon dioxide in
the air Also some liquid chemicals may "freeze." A 50
percent sodium hydroxide solution becomes crystalized
(forms a solid) at temperatures below 55°F (13°C). Therefore
a heater may be required to keep the storage area warm or
the solution may have to be diluted down to a 25 percent
solution.

Potassium permanganate can be kept indefinitely if stored
in a cool dry a''ea in closed containers. The drums should be
protected from damage that could cause leakage. Potas-
sium permanganate should be stored in fire-resistant build-
ings, having concrete floors as opposed to wooden floors. It
should not be exposed to intense heat, or stored next to
heated pipes Any organic solvent, such as greases and oils
in general, should be kept away from stored KMnO^.

Potassium permanganate spills should be swept up and
removed Immediately. Flushing with water is an effective
way to eliminate spillage on floors. Potassium permangan-
ate fires should be extinguished with water.

Carbon should be stored in a clean, dry place, in single or
double rows, and with access aisles around every stack for
frequent fire inspections. The removal of burning carbon will
thus be facilitated. Carbon should never be stored in large
stacks.

The storage area should be of fireproof construction, with
self-closmg fire doors separating the carbon room from
other sections. Storage bins for dry bulk carbon should be of
fireproof construction equipped for fire control by the instal-
lation of carbon dioxide equipment, or should be so ar-
ranged that they can be flooded with a fine spray of water.

Ca;bon storage areas should be protected from contact
with flammable materials. (Carbon dust mixed with oily rags
or chlorine compounds can ignite in spontaneous combus-
tion.) SMOKING SHOULD BE PROHIBITED AT ALL TIMES
DURING THE HANDLING AND UNLOADING OF CARBON
AND IN THE STORAGE AREA. Carbon should not be stored
where a spark from overhead electric equipment could start
a fire. If a fire occurs, the carbon monoxide hazard should be
taken into account.

Electnc equipment should be protected from carbon dust
and cleaned frequently or, better, explosion-proof electric
wiring and eauipment should be used. (The heat from a
motor may ignite the accumulated carbon dust, this material,
especially when damp, is a g ^od conductor of electncity and
could short-circuit the mechanism.)

Polymer sc'utions will be degraded (lose their strength) by
bioloq»cal contamination. A good cleaning of polymer stor-
age tanks IS recommended before a new shipment is deliv-
ered to the plant.

Liquid chemical storage tanks should have a berm or
earth bank around the tanks to contain any chemicals
released if the tank fails due to an earthquake, corrosion or
any other reason.

Some chemicals such as chlonne and fluoride compounds
are harmful to the human body when they are released as
the result of a leak. Continual surveillance and maintenance
of the storage and feeding systems are required.

2» For additional information on chemical feeders, see Chapter 13, Fluoridation, Section 13 30, "Chemical Feeders
22 Hygroscopic (HI-grow-SKOP-ick). Absorbing or attracting moisture from the air.

ERIC

33/

Maintenance 317

18.41 Drainage from Chemical Storage and Feeders

Safety regulations prohibit a single drainage pit which can
accept and contain both acid and alkali chemicals because
of the possibility of an explosion whenever these two types
of chemicals come in coiitact. Also, any organic chemical
waste such as a polymer solution should not be allowed to
be discharged into a pit or sump which could also receive a
waste from oxidizing chemicals such as potassium perman-
ganate (KMnO^) because of the possibility of a fire. There-
fore, separate drainage systems or a high dilution of certain
chemicals are necessary for a safe drainage system.

18.42 Use of Feeder Manufacturer's Manual

Water treatment plants will have a number of chemical
feeders to accurately control the i ate at which chemicals are
fed into the water as a part of the treatment processes
There are many types of feeders and they work on many
different principles. Study the feeder manufacturer's manual
that you should find in the treatment plant library for details
on maintaining the equipment. Additional information on
chemical feeders is contained in specific chapters on treat-
ment processes that require the use of chemical feeders.

18.43 Solid Feeders

Solid feeders usually handle powdered material and usu-
ally have many moving mechanical parts that need adjust-
ment, lubrication, and replacement when worn. The chemi-
cal supply IS usually stored in a hopper. Keep the hopper
and feeder clean and dry in order to prevent "bndging" (a
hardened layer which can form an arch and prevent flow) of
the chemical in the hopper and clogging in the feeder.

18.44 Liquid Feeders

Liquid feeders handle many types of chemicals, some of
which may be corrosive and/or have a tendency to plug up
the mechanism. The key to reliable operations is constant
vigilance and cleaning as needed

18.45 Gas Feeders

The principal chemical found in gaseous form at water
treatment plants is chlorine Chlonne is quite poisonous to
humans and must be handled with great caution

18.46 Calibration of Chemical Feeders^^

To ensure chemical feed rates, liquid-chemical metering
pumps and dry-chemical feed systems should be tested and
calibrated when first installed and at regular intervals there-
after. This section presents general proceaures for calibrat-
ing several types of liquid- and dry-chemical feeders.

18.460 Large-Volume Metering Pumps

Pumps metering chemicals such as liquid alum deliver a
relatively large volume of chemical in a short time period.
These pumps can be accurately calibrated with a clear
plastic sight tube and a stopwatch (Figure 18.51).

To calibrate 'ine pump, fill the sight tube from the chemical
solution tank, then set the valve so the tube Is the only
source of liquid chemicai entering the pump. Run the pump
for exactly one minute (use the stopwatch) at each of five or

SIX representative settings of the pump-control scale. Re-
cord the amount pumped at each setting as observed in the
Sight tube Use this information to develop curves of pump
setting vs chemical dose in mg//_ or chemical feed in gallons
per day for your plant (Figure 18.52).

The graph developed by this process is called a calibration
curve it can be used to determine the pump setting needed
to deliver a required chemical feed rate, or the commonly
used range of feed rates can be marked in gallons per day
directly on the pump control panel.

18.461 Small-Volume Metering Pumps

Pumps metering a chemical such as sodium hexameta-
phosphate, a lime feed solubility enhancer, feed a very small
volume per day. The procedure for calibration of these
pumps IS similar to the procedure for large-volume units. For
very low feed rates, pumping times of longer than one
minute may be required to give accurately measurable
results.

Once the test data have been recorded, convert the test
results to appropriate units and draw a calibration curve to
be used as for the larger pumps.

18.462 Dry-Chemical Systems

Dry-chemical feed systems are used for chemicals such
as activated cartx)n, fluoride, and lime. Two types of sys-
tems are common, the rocker-dump type and the helix-feed
type The rocker-dump chemical feed uses a scraper moving
back and forth on a platform located at the bottom of a
hopper filled with dry chemical The platform may be adjust-
ed up and down to regulate the thickness of the nbbon of
chemical, and the length of stroke for the scraper can be
adjusted, usually by means of an indicator on an exterior
arm.

The helix-type feeder feeds the dry chemical with a
rotating screw (helix). The feed rate is adjusted by varyng
the drive-motor speed. The speed can usually be vaned from
0 to 100 percent.

To calibrate either type of feed system, choose five or six
representative settings of the arm (rocker-dump) or of the
motor speed control (helix type), and a, each of the settings
catch the amount of chemical fed dunng a precisely meas-
ured time interval. Next, weight each volume of chemical as
accurately as possible and convert the information into
pounds per day. Use the data to construct a calibration
curve with one axis representing feeder settings and the
other representing pounds per day. The curve is used in the
same manner as the curves for licuid-feed pumps.

FORMULAS

To determine the chemical feed rate or flow from a
chemical feeder, we need to know the amount or volume fed
during a known time period. The flow from a chemical feeder
can be calculated by knowing the volume pumped from a
chemical storage tank and the time period.

Flow, GPM =

or Flow, GPM =

Volume Pumped, gal
Pumping Time, minutes
(Volume Pimped, gal) (24 hr/day)
(Pumping Time, hour)

For additional information on i.^i!.trct.Kjn of chemical feeders, see Volume L Appendix Section A 13h Chemical Doses, pages
^ 567-570.

ERIC

333

•A
00

CHEMICAL
SOLUTION
TANK

(CHLORINE, ALUM, ETC.)

CLEAR PLASTIC
GRADUATED
CYLINDER
MARKED IN
MILLILITERS

9
3

ID
3

->-T0 POINT OF

CHEMICAL INJECTION

CHEMICAL
SOLUTION
FEED PUMP

THE FEED RATE OF A CHEMICAL SOLUTION FEED PUMP CAN BE DETERMINED BY MEASURING THE AMOUNT OF
SOLUTION WITHDRAWN FROM A GRADUATED CYLINDER IN A GIVEN TIME PERIOD. ALLOW THE CYLINDER TO FILL WITH
SOLUTION. THEN CLOSE THE VALVE ON THE LINE FROM THE TANK SO THE FEED PUMP TAKES SUCTION FROM THE
CYLINDER ONLY. OBSERVE THE MILLILITERS OF SOLUTION USED IN ONE MINUTE. COMPARE THIS RESULT WITH THE
DESIRED FEED RATE AND ADJUST THE FEED PUMP ACCORDINGLY.

Fig. 18,51 Calibration of a chemical feed pump

ERIC

Maintenance 31S

CHEMICAL DOSE, mg/L

Fig. 18.52 Chemical feed pump settings for various chemical doses

Liquid polymer feed rates are often measured in pounds
per day. To calculate this feed rate we need to know the
strength of the polymer solution as a percent or as milli-
grams per liter, the specific gravity of the solution, the
volume pumped and the time period.

Polymer ^ (ppiy Conc. mg/L) (Vol Pumped, mi) (60 min/hr) (24 hr/day)
Ibs^day ' ^^^"^^ Pumped, mm) (1000 mL/L) (lOOO mg/gm) (454 gm/lb)

To determine the actual feed from a dry chemical feeder, we
need to know the pounds of chemical fed and the time
period.

Chemical
Feed,
lbs/day

(Chemical Fed, lbs) (60 min/hr) (24 hr/day)
Time, minutes

EXAMPLE 2

A chemical feed pump lowered the chemical solution in a
four-foot diameter chemical storage tank two feet during a
seven-hour period. Estimate the flow delivered by the pump
in gallons per minute ana gallons per day.

Known
Tank Diameter, ft = 4 ft
Chemical Drop, ft = 2 ft
Time, hr = 7 hr

Unknown

Flow, GPM
Flow, GPD

1. Determine the volume of water pumped in gallons,
volume, gal - (0 785) (Diameter, ft)2 (Dron. ft) (7 48 gai/cu ft)
= (0 785) (4 ft)2 (2 ft) (7 48 gal/cu ft;
- 188 gal

2 Calculate the flow from the chemical feed pump in gallons
per minute.

Flow, GPM

Volume Pumped, gal
(Pi-Tiping Time, hr) (60 min/hr)

188 gal
(7 hr) (60 min/hr)

0 45 GPM

3 Calculate the flow from the chemical feed pump in gallons
per day.

Flow, GPD =

(Volume Pumped, gal) (24 hr/day)

Pumping Time, hr
(188 gal) (24 hr/day)

7 hr

- 645 GPD

320 Water Treatment

EXAMPLES

Determine the chemical feed in pounds of polymer per day
from a chemical feed pump. The polymer solution is 2 C
percent or 20,000 mg polymer per liter Assume a specific
gravity of the polymer solution c' 1.0. During a test run the
chemical feed pump delivered '50 m/_ of polymer solution
during six minutes.

Unknov^n

Polymer Feed,
lbs/day

Known

Polymer Solutio'^. % = 2 0%
Polymer Cone, mg/L - 20,000 mg//.
Polymer SpGr = 1.0
Volumed Pumped, m/_- 750 mL
Time Pumped, mm = 6 mm

Calculate the polymer feed by the chemical feed pump in
pounds of polymer per day.

Polymer (Poiy Conc. mg/L) (Vol Pumped, ml) (60 mm/hr) (24 hr/clay)

Feed. ^

lbs/day ^ ' ""^ Pumped, mm) (1000 mL/L) (1 000 mg/gm) (454 gm/lb)

_ (20.000 mg/L) (750 mL) (60 min/hr) (24 hr/day)
(6 mm) (1000 mL/L) (1000 mg/gm) (454 gm/lb)
- 7 9 lbs polymer/day

EXAMPLE 4

Determine the actual chemical fed in pounos per day from
a dry chemical feeder A pie tin placed under a chemical
feeder collected 1000 grams of chemical in five minutes.

Known Unknown

Dry Chemical, gm = 1000 gm Chemical Feed, lbs/day
Time, mm = 5 mm

Determine the chemical feed in pounds of chemical applied
per day.

*"Feed'^^' = (Chemical Applieo, gm) (60 mm/hr) (24 hr/day)
lbs/day (454 gm/lb) (Time, mm)

(1000 gm) (60 miri/hr) (24 hr/day)
(454 gm/lb) (5 min)
- 635 lbs/day

18.47 Chlorinators

Chlonne gas leaks around chlorinators oi containers of
chlorine will cause corrosion of equipment Check every day
for leaks. Large leaks will be detected by odor: small leaks
may go unnoticed until damage results. A green or reddish
deposit on metal indicates a chlorine leak. Any chlonne gas
leakage m the presence of moisture will cause corrosion.
Always plug the ends of any open connection to prevent
moisture from entering the lines. Never pour water on a
chlorine leak because this will only create a bigger problem
by enlarging the leak. Chlonne gas reacts with water to form
hydrochloric acid.

WARNING

Toxic mi man^.

Ammonia water will detect any chlorine leak. A small piece
of cloth, soaked with ammonia water^"* and wrapped around
the end of a short stick, makes a good leak detector Wave
this stick m the general area of the suspected leak (do not
touch the equipment ^vith it) if chlorine gas leakage is
occunng. a white cloud of ammonium chloride will form You
should make this test at all gas pipe joints, both inside and
ou\side the chlorinators, at regular intervals. Bottles of
ammonia water should be kept tightly capped to avoid loss
of strength. All pipe fittings must be kept tight to avoid leaks.
NEW GASKETS SHOULD BE USED FOR EACH NEW CON-
NECTION

CAUTION

tOLOCATe A CHUOC?)NB L^Ak, 170 MOT
SP(?AV OI? ->WAS eOUlPAACrMT W\-r+A
AMMONIA WAXe V WAVGr AM AMMON\A-
-$OAKEP t2ACEr O^ p/^^iNrr H>RU-bH INlT^E
<^BH^^A^ AP^A AK\P VOO CAIvi PeTECT
PRESENCE: OP A^AMV LeAk:^.40Me
OPECATO^a^ ^BPBHTO WAVE A -STiCfel WITH
A CLOTK OM THeENP iM PCOMTOP TUEM
WWEMTf^EV At?E iO0\^\N6x C[\LOU.\ ME

Do not use a spray bottle in a room where large amounts
of chlcnne gas have already leaked into the air. After one
squeeze, the entire area may be full of white smoke and you
will have troi jle locating the leak. Under these conditions,
use a cloth t^oaked in ammonia water to look for leaks.

The exterior casing of chlorinators should be painted as
required, however, most chlonnators manufactured recently
have plastic cases ♦hat do not require protective coatings. A
clean machine is a better op^^ itmg machine. Parts of a
chlonnator handling chlorine gas must be kept dry to prevent
the chlorine ard moisture from forming hydrochloric acid.
Some parts may be cleaned, when required, first with water
to remove water soluble material, then with wood alcohol,
followed by drying The above chemicals leave no moisture
residue. Another method would oe to wash them with water
and dry them over a pan or heater to remove all traces of
moisture.

Water strainers on chlorinators frequently clog and re-
quire attention They may be cleaned by flushing with water
or. if badly fouled, they may be cleaned with r'llute hydro-
chloric acid, followed with a water . mse.

The atmosphere vent lines from nhlormators must be
opeii and free. These vent lines evacuate the chlorne to the
outside atmosphere when the chlonnator is being shut
down. Place a screen over the end of the pipe to keep
insects from building a nest in the pipe and clogging it up.

When chlonnators are removed from service, as much
chlonne gas as possible should be removed from the supply
lines and machines. The chlonne valves at the containers
are shut off and the chlonnator injector is operated for a
penod to remove the chlonne gas. In "V" notch chlonnators,
the rotameter goes to the bottom of the manometer tube
when the chlorine gas has been expelled.

All chlonnators will give c^ tinuous t- )uble-free operation
if properly maintained and operated ^ach chlonnator manu-
facturer provides with each machine a mamtena'^ce and
operations instruction booklet with line diagrams showing
the operation of the component parts of the machine.
Manufacturer's instructions should be followed for mainte-

24 Use a concentrated ammcma solution containing 28 to 30 percent ammonia as NH3 (this is the same as 58 percent ammonium hydrox-
ide, NH4OH, or commercial 26"" Baume).

Maintenance 321

nance and lubrication of your particular chlonnator. If you do
not have an instruction booklet, you may obtain one by
contacting the manufacturer s representative in your area

QUESTIONS

Wnte your answers in a notebook and then compare your
answers with those on page 327

18 4A How can an operator locate information on how to
operate, control and maintain chemical feeders''

18 4B List three common types of chemical feeders

1 8 4C Why should chlorine leaks be detected and repaired''

18 4D How would you search for chio .we leaks''

18.5 TANKS AND RESERVOIRS^^

18.50 Scheduling Inspections

Plant tanks should be drained and inspected at regular
intervals If the interior is well protected, five-year intervals
between inspections may be sufficient If the tank is below
the surface of the ground, be sure the groundwater level is
down far enough (below the bottom of the tank) so the tanks
will not float on the groundwater when empty or develop
cracks from groundwater pressure.

Schedule inspections o< tanks and channels during per-
iods of low plant demand so that plant operation won t be
disrupted

18.51 Steel Tanks

All steel tanks must be protected from rusting Once metal
IS lost because of rusting, it can t be recovered. The ex-
teriors of the tanks are easily inspected — don t forget the
roof — and should be repainted, as needed, not only to
protect the steel surface but to provide a pleasing appear-
ar.ce. The interiors of steel tanks are exposed to a much
harsher environment due either to being constantly sub-
merged or to constant high humidity.

Protective coatings for steel tank interiors must be care-
fully selected to provide superior protection and at the same
time impart neither taste nor odors to the water Proper
surface preparation and application is as important as the
coating materials in getting interior protection that will last a
reasonable period of time

When interior tank recoating is required, schedule the
work when plant demand is low but not dunng rainy weather
when it may be impossible to maintain a dry steel surface
warm enough to ensure proper curing of the coating. This
type of work is usually done by outside contrac'.ors. Con-
stant inspection is a must if the work is go.ng to be
completed according to the specifications.

18.52 Cathoaic Protections^

An alternative to repainting the submerged interior sur-
faces of a steel water tank is installation of a cathodic
protection system. The rusting of steel is accompanied by
the flow of small electrical currents. Cathodic protection
systems prevent rusting of bare steel surfaces by causing
an electrical current to flow from anodes hung in the water to

the tank surface The polarity of this current is opposite to
what It would be if rust were forming The current can be
obtained from sacrificial anodes that make the tank into a
giant low voltage battery, or from electronic rectifiers that
are powered from the commercial power lines.

Cathodic protection systems provide protection only so
long as they are operat ng and properly idjusted Systems
with rectifiers should be checked weekly. The inspection
consists of reading and record . the DC volt and ammeter
readings Compare the readings with previous readings and
with the readings recommended by the corrosion engineer
or technician Deviations from normal should be investigated
without delay

Once a year, a corrosion specialist should be called in to
take potential profile readings on the inside of the tank and
to set the rectifier and recommend new normal current
settings. Over the years, as more and more of the interior
tank coating fails, the bare surface area to be protected by
the cathodic protection system will increase. For this reason.
It IS to be expected that the current required to provide
protection will increase m small amounts or increments each
year

18.53 Concrete Tanks

Concrete tanks are not usually coated on the inside and
are painted on the exterior for appearance purposes only.
This would seem to indicate that maintenance on concrete
tanks IS minimal, but this may not be true Concrete tanks
are all reinforced with steel Steel can rust. If too much steel
IS lost to rust, the structural strength of the tank can be
threatened Periodically inspect the tank for signs of rusting.
This IS particularly important for pre-stressed concrete tanks
that have a tensioned wire wrap on the exterior. The wires
are small in diameter and even a small amount of rust could
reduce the size of the wire to the point where it might faJ.

QUESTIONS

Write your answers in a notebook and then compare your
answers w ^h those on page 327.

18 5A How often should tanks and reservoirs be drained
and inspected''

1 8 SB Why must the groundwater level be below the bottom
of a tank before it is drained?

18 50 What IS an alternative to applying a protective coat-
ing to prevent corrosion of a steel tank''

18.6 BUILDING MAINTENANCE

Building maintenance is another program that should
receive attention on a regular schedule Buildings in a
treatment plant are usually built of sturdy materials to last for
many years, if they are kept in good repair. In selecting paint
for a treatment plant, it is always a good idea to have a
painting expert help the operator select the types of paint
needed to protect the buildings from deterioration. The
expert also will have some good ideas as to color schemes
to help blend the plant in with the surrounding area. Consid-
eration should also be given to the quality of paint A good
quality, more expensive material will usually gr'^ better
service over a longer period of time than the economy-type
products.

25>%/so r.ee WATER DISTRIBUTION SYSTEM OPERATION AND MAINTENANCE, Chapter 2. Storage Facilities, Section 2.4, "Mamte-
nance," in this series of manuals.

^^Also see Chapter 8, Corrosion Control, Section 8.36. Xatholic Protectionism WATER TREATMENT PLANT OPERATION, Volume 1.

ERLC

322 Water Treatment

Building maintenance programs depend on the age, t/oe
and use of a building New buildings require a thorough
check to be certain essential items are available and working
properly Older buildings require careful watching and
prompt attention to keep ahead of leaks, breakdowns,
replacements when needed, and changing uses of the
building Attention must be given to the maintenance re-
quirements of many items in all plant buiMings, such as
etectncal systems, plumbing, heating, coo!' ^g, ventilating,
floors, windows, roofs, and drainage around the buildings.
Regularly scheduled examinations and necessary mainte-
nance of these Items can prevent many costly and time-
consuming problems in the future

In each plant building, periodically check all stairways,
(adders, catwalks, and platforms for adequate lighting, head
clearance, and sturdy and convenient guardrails Protective
devices should surround all moving equipment. Whenever
any repairs, alterations, or additions are built, avoid building
accident traps such as pipes laid on top of floors or hung
from the ceiling at head height, which could create serious
safety hazards.

Organized storage areas should be provided and main-
tained in an accessible and neat manner.

KEEP ALL BUILDINGS CLEAN AND ORDERLY. Janitorial
work should be done on a regular schedule. All tools and
plant equipment should be kept clean and in tneir proper
place. Floors, walls, and windows should be cleaned at
regular intervals in order to maintain a neat appearance. A
treatment plant kept in a clean, orderly condition makes a
safe place to work and aids in building good public and
employer relations.

QUESTIONS

Wnte your answers in a notebook and then compare your
answers with those on page 327.

18 6A What items should be included in a build-ng mainte-
nance program*?

18 6B What factors influence the type of building mainte-
nance program that might be needed for your water
treatment planf?

18.7 ARITHMETIC ASSIGNMENT

Turn to the appendix at the back of this manual and read
Section A 35, 'Maintenance " Also work the example prob-
lems and check the arithmetic using your calculator You
should be able to get the same answers

18.8 ADDITIONAL READING

1. NEW YORK MANUAL, Chapter 19, "Treatment Plant
Maintenance and Accident Prevention

2. TEXAS MANUAL, Chapter 13. "Pumps and Measurement
of Pumps "

18.9 ACKNOWLEDGMENTS

Major portions of this chapter were taken from the follow-
ing California State University, Sacramento, Operator Man-
uals

1. OPERATION OF WASTEWATER TREATMENT PLANTS

Volume 11, Chapter 15, "Maintenance," by Norman
Farnum, Stan Walton, John Brady, Roger Peterson
and Malcolm Carpenter.

2 OPERATION AND MAINTENANCE OF WASTEWATER
COLLECTION SYSTEMS

Chapter 9, "Equipment Maintenance, " by Lee Doty.

3. INDUSTRIAL WASTE TREATMENT
Chapter 7, "Maintenance," by Roger Ham.

OVl

DISCUSSION AND REVIEW QUESTIONS

Chapter 18. MAINTENANCE

(Lesson 5 of 5 Lessons)

Write your answers to these questions in your notebook
before continuing to the objective test on page 327. The
question numbering continues from Lesson 4

36 What factors could cause gasoline engine starting prob-
lems'?

37. Why IS rust a problem in water-cooled systems?

38 What IS the purpose of the fillers in the diesel fuel
system?

39 What are the advantages of air-cooled diesel engines as
compared with water-cooled types'?

40 How should large quantities of gasoline be stored'?

41 Why IS "idling" not a satisfactory method of testi.ig
standby engines?

42 Why should ory chemical fee^prs and hoppers be kept
clean and dry?

43 V\/hat problems can be caused by chlorine gas leaks
around chlorinators or containers of chlorine'?

ERIC

•6U

Maintenance 323

SUGGESTED ANSWERS

Chapter 18. MAINTENANCE

ANSWERS TO QUESTIONS IN LESSON 1

Answers to questions on page 220

1 8 OA A good maintenance program is es- ?ntial for a water
treatment plant to operate at peak efficiency.

18 OB The most important item is maintenance of the
mechanical equipment — pumps, valves, scrapers,
and other moving equipment. Other items include
plant buildings and grounds.

1 8 OC A good record system tells when maintenance is cue
and also provides a record of equipment perform-
ance. Poor performance is a good justification for
replacement o" new equipment. Good records help
keep your warranty in force.

18.0D Both cards are vital in a good recordkeeping system.
The equipment service record card is a permanent or
master card that indicates when or how often certain
maintenance work should be done. The service rec-
ord card IS a record of who did that work on what
date and is hel? ul in determining when the future
maintenance w^ik is due.

18 OE Emergency phone numbers for a treatment plant
should include the phone numbers for police, fire,
hospital and/or physician, responsible plant officials,
local emergency disaster office, emergency team
and CHEMTREC. (800) 424-9300.

18.0F A training program for an emergency team should
include:

1. Use of proper equipment (self-contained breath-
ing apparatus, repair kits and repair tools),

2. Properties and detection of hazardous chemicals,
3 Safe procedures for handling and storage of

chemicals,

4. Types of containers, safe procedures for shipping
contain ..-rs, and container safety devices,

5. Installation of repair devices, and

6. Simulated field emergencies

Answers to questions on page 221.

18.1 OA Unqualified or inexperienced people must be ex-
tremely careful when attempting to troubleshoot or
repair electrical equipment because they can be
seriously injured and damage costly equipment if a
mistake is made.

18.10B When machine is not shut off. locked out, and
tagged properly, the follo'vng accidents could oc-
cur:

1. Maintenance operator could be cleaning pump
and have it start, thus losing an arm, hand or
finger;

2. Electrical motors or controls not properly
grounded could lead to possible severe shock,
paralysis, or death; and

3. Improper circuits such as a wrong connection,
safety devices jumped, wrong fuses, or improp-
er wiring can cause fires or Injunes due to
incorrect operation of machinery.

Answers to questions on page 225.

18 11A The two types of current are Direct Current (D.C.)
and Alternating Current (A C ).

1 8 1 1 B Amperage is a measurement of work being done or
"how hard the electricity is working."

18 lie The proper voltage and allowable current in amps
for a piece of equipment can be determined by
reading the name plate information or the instruc-
tion manual for the equipment.

Answers to questions on page 230.

18 12A You test for voltage by using a voltage tester

18 12B A voltage tester can be used to test for voltage,
ooen circuits, blown fuses, single phasing of mo-
tors and grounds.

18.12C Before attempting to change fuses, turn off power
and check both power lines for voltage Use a fuse
puller.

18.12D If the voltage is unknown and the voltmeter has
different scales that are manually set, always start
with the highest voltage range and work down.
Otherwise the voltmeter could be damaged.

18.12E Amp readings different from the name plate rating
could be caused by low voltage, bad bearings, poor
connections, plugging or excessive load.

1 8 1 2F Motors and winngs should be megged at least once
a year, and twice a year if possible.

18 12G An ohm meter is used to test the control circuit
components such as coils, fuses, relays, resistors
and switches.

Answers to questions on page 231.

18.13A The two types of safety devices in main electncal
panels or control units are fuses or circuit breakers.

18.13B Fuses are used to protect operators, wi' ^, cir-
cuits, heaters, motors, and various other electrical
equipment,

l8.i3C A fuse must never be by-passed or jumped be-
cause the fu£.e may be the only protection the
Circuit has; without it, serious damage to equipment
and possible injury to operators can occur.

18 13D A Circuit breaker is a switch that is opened auto-
matically when the current or the voltage exceeds
or falls below a certain limit. Unlike a fuse that has
to be replaced each time it "blows," a circuit breaker
can be reset after a short delay to allow time for
cooling.

18.13E Motor starters can be either manually or automati-
cally controlled.

18.13F Magnetic starters are generally used to start
pumps, compressors, blowers and anything where
automatic or remote control is desired,

ERIC

324 Water Treatment

Answers to questions on page 234.

18 14A Electrical energy is commonly converted into me-
chanical energy by electric motors.

18.14B An electric motor usually consists of a stator, rotor,
end bells, and windings.

1 8 1 4C Motors can be kept trouble free with proper lubrica-
tion and maintenance.

18 14D Motor name plate data should be recorded, com-
pared with manufacturer's data sheets and instruc-
tions, and placed in a file for future reference. Many
times the name plate Is painted, corrodes or is
missing from ♦he unit when the information is need-
ed to repair the motor or replace parts

18.16D Symptoms that a power distribution transformer
may be in need of maintenance or repair include
unusual noises, high - 'ow oil levels, oil leaks or
high operating temperatures.

Answers to questions on page 247.

1 8 1 7A Rusted conduits are of concern because they could
become the source of a spark which could cause an
explosion.

18 17B Electrical safety check lists are used to make
operators awcre of potential electrical hazards in
their water treatment plant.

Answers to questions on page 236.

18.14E The key to effective troubleshooting is practical,
step-by-step procedures combined with a common
sense approach.

18 14F When troubleshooting:

A. Gather preliminary information.

B. Inspect:

1. Contacts,

2. Mechanical parts, and

3. Magnetic parts.

18.14G Types of information that should be recorded re-
garding electrical equipment mcluc* even/ change,
repair and test.

Answers to questions on page 246.

18.15A A qualified electrician should perform most of the
necessary maintenance and repair of electrical
equipment to avoid endangering lives and to avoid
damage to equipment.

18.15B The purpose of a "kirk-key" system (one key is used
for two locks) Is to Insure proper connection of
standby power into your power distribution system.
The commercial power system must be locked out
by the use of switch gear before the standby power
IS connected to your power distnbution system.

18.15C Battery-powered lighting units are considered bet-
ter than engine-driven power sources because they
are more economical. If you have a momentary
power outage, the system responds without an
engine-generator startup.

18.150 If water lost from a lead-acid battery is replaced
With tap water, the impurities in the water will
become attached to the lead plates and shorten the
life of the battery.

Answers to questions on page 247.

18.16A Electricity Is transmitted at high voltage to reduce
the size of transmission lines.

18 16B If outdoor transforme'-'^ have exposed high voltage
wires, the following precautions must be taken:

1. An eight foot (2.4 m) high '-^^nce is required to
prevent accessibility by un- ilified or unauthor-
ized persons; and

2. Signs attached to the fence must indicate "High
Voltage."

18.16C The treulTient plant operator must keep the exteri-
or and surroundings of the switch gear clean.

ERIC

ANSWERS TO QUESTIONS IN LESSON 2

Answers to questions on page 258

18.20A Pieces of equipment and special tools commonly
found in a pump repair shop include welding equip-
ment, lathes, drill press and drills, power hack saw,
flame-cutting equipment, micrometers, calipers,
gages, portable electric tools, grinders, a forcing
press, metal-spray equipment, and sand-blasting
equipment.

1 8 21 A The purpose of a pump impeller is to suck water in
the suction piping and to throw water out between
the impeller blades.

1 3 21B A suitable screen should be installed on the intake
end of suction piping to prevent foreign matter
(sticks, refuse) from being sucked into the pump
and clogging or wearing the Impeller.

18 21C Suction piping must be up-sloping to prevent air
pockets from forming in the top of a pipe where air
could be drawn into the pump and cause the loss of
suction.

18.21D Cavitation is the formation and collapse of a gas
pocket or bubble on the blade of an impeller. The
collapse of this gas pocket or bubble drives water
into the impeller with a terrific force that can cause
pitting on the Impeller surface.

18 21 E An advantage of a double-suction pump Is that the
longitudinal thrust from the water entering the im-
peller is balanced.

Answers to questions on page 263,

18 22A The purpose of lubrication is to reduce friction
between two surfaces and to remove heat caused
by friction.

18 22B Oils in service tend to become acid (contaminated)
and may cause corrosion, deposits, sludging and
other problems.

18 22C To ensure proper lubrication of equipment, deter-
mine the proper lubrication schedule, lubricant, and
amount of lubricant and prepare a lubrication chart.

Answers to questions on page 264

18 22D A soft grease has a low viscosity index as com-
pared with a hard grease.

18 22E Oil IS used with higher speeds.

18 22F Overfilling with oil or grease can result in high

pressures and temperatures, and ruined seals or

other components.

346

Maintenance 325

ANSWERS TO QUESTIONS IN LESSON 3

Answers to questions ^n page 272

18 23A A cross-connection is a connection between two
piping systems where an undesirable water (water
from water seal) could enter a domestic water
supply.

18 23B Yes. A slight leakage is desirable when the pumps
are running to keep the packing cool and in good
condition.

18 23C To measure the capacity of a pump, measure the
volume pumped during a specific time period

Volume, gallons

v:apacity. GPM

Capacity.

Time, minutes

liters Volume, liters

18 23D

Capacity. GPM

sec Time, sec
Volume, gallons

Time, minutes

(10 ft) (15 ft) (1 7 ft) (7 5 gal/cu ft)

5 minutes

Capacity

382 5 GPM

liters Volume, liters

sec Time, sec

(3 m) (5 m) (0 5 m) (1000 L/cu m)

(5 minutes) (60 sec/mm)
25 liters/sec

1 8 23E Before a prolongeo shutdown, the pump should be
drained to prevent damage from corrosion, sedi-
mentation, and freezing Also, the motor disconnect
switch should be opened to disconnect motor

Answers to questions on page 274

18 23F Shear pins commonly fail in leciprocating pumps
because of (1) a solid object lodged under piston,
(2) a clogged disc' Jrge line, or (3) a stuck or
wedged valve

18 23G A noise may develop when pumping thin sludge
due to water hammer, but will disappear when
heavy sludge is pumped.

18 23H Higher than normal discharge pressures in a pro-
gressive cavity pump may indicate a line blockage
or a closed valve downstream

Answers to questions on page 274

18.231 When checking an electric motor, the following
Items should be checked periodically, as well as
when trouble develops:

1 . Motor condition,

2. Note all unusual conditions,

3. Lubricate bearings,

4. Listen to motor, and

5. Check temperature.

1 8.23J The purpose of a stethoscope is to magnify sounds
and carry them to the ear. This instrument is used
to detect unusual sounds in electric motors such as
whines, gratings, or uneven noises.

Answers to questions on page 278.

1 8 23K A properly adjusted horizontal belt has a slight bow
in the slack side when running. When idle, it has an
alive spnnginess when thumoed with the hand,
vertical belts should have a springmeso when
thumped. To check for proper alignment, place a
straight edge against the puller face or faces. If a
ruler won't work, use a transit for long runs, or the
belt may be examined for wear.

18 23L Always replace sprock(its v/hen replacing a chain
because old. out-of-pitch sprockets cause as much
Cham wear in a few hours as years of normal
operation

Answers to questions on page 280

18 23M Improper original installation of equipment, settling
of foundations, heavy floor loadings, warping of
bases, and excessive bearing wear could cause
couplings to become out of alignment.

1 8 23N Shear pins are designed to fail if a sudden overload
occurs that could damage expensive equipment.

Answers to questions on page 283.

1 8 24A Pumps must be lubricated in accordance with man-
ufacturer's recommendations Quality lubricants
should be used.

18 24B In lubricating motors, too much grease may cause
bearing trouble or damage the winding

Answers to questions on page 283.

18.24C If a prmp will not start, check for blown fuses or
tnpped Circuit breakers and the cause. Also check
for a loose connection, fuse, or thermal unit.

1 8 24D To increase the rate of discharge from a pump, you
should lock for something causing the reduced rate
of discharge, such as pumping air, motor malfunc-
tion, plugged lines or valves, impeller problems, or
other factors.

Answers to questions on page 284.

18 24E If a pump that has been locked or tagged out for
maintenance or repairs is started, an operator
working on the pump could be seriously injured and
also equipment could be damaged.

1 8 24F Normally a centrifugal pumo should be tarted after
the discharge valve is o,.ened. Exceptions are
treatment processes or piping systems with vacu-
ums or pressures that cannot be dropped or al-
lowed to fluctuate greatly while an alternate pump
IS put on the line. If the pump is not equipped with a
check valve and the discharge pressure is higher
than the suction pressure under static conditions,
the pump could run backwards and cause damage
to the equipment.

Answers to questions on page 286.

18 24G Before stopping an ope ating pump:

1 Start another pump (if appropriate); and

2 Inspect the operating pump by looking for devel-
oping problems, required adjustments, and
problem conditions of the unit.

347

326 Water Treatment

18 24H A pump shaft or motor will spin backwards if water
being pumped flows back through the pump when
the pump IS shut off. This will occur if there is a
faulty check valve or foot valve m the system.

18.241 The position of aii valves should be checked before
starting a pump to ensure that the water being
pumped will go where intended.

Answers to questions on page 286.

18 24 J The most important rule regarding the operation of
positive displacement pumps is to NEVER start the
pump against a closed discharge valve.

18.24K If a positive displacement pump is started against a
closed discharge valve, the pipe, valve or pump
could rupture from excessive pressure. The rupture
will damage equipment and possibly seriously in-
jure or kill someone standing nearby.

18 24L Both ends of a sludge line should never be closed
tight because gas from decomposition can build up
and rupture pipes or valves.

ANSWE" " TO QUESTIONS IN LESSON 4

Answers to questions on page 289.

18 25A Compressors are used with water ejectors, pump
control systems (bubblers), valve operators, and
water pressure systems. Also they are used to
operate portable pneumatic tools such as jack
hammers, compactors, air drills, sand blasters,
tapping machines, and air pumps.

18 25B The frequency of cleaning a suctic i filter on a
compress depends on the use of a compressor
and the atmosphere around it. The filter should be
inspected at least monthly and cleaned or replaced
every three to six months. More frequent inspec-
tion, cleaning and replacement are required under
dusty conditions such as operating a jack hammer
on a street.

18 25C Compressor oil should be changed at least every
three months, unless manufacturer states different-
ly. If there are filters .n the oil system, these also
should be changed.

18.25D Dram the condensate from the air receiver daily.

18 25E Before testing belt tension on a compressor v;ith

your hands, MAKE SURE COMPRESSOR !S

LOCKED OFF.

Answers to questions on page 305.

18.26A Valves are the controlling devices placed in piping
systems to stop, regulate, check, divert, or other-
wise modify the flow of liquids or gases.

18.26E Six common types of valves found in water treat-
.ent facilities include gate valves, globe valves,
eccentnc valves, butterfly valves, check valves and
plug valves.

18.260 The purpose of the check valve is to allow water to
flow In one direction only.

18.26D Backflow prevention by check valves is essential in
many applications to:

1. Prevent pumps from reversing when power Is
removed,

2. Protect water systems from being cross-con-
.lected,

ERLC

3 Aid in pump operation as a dampener, and

4 Ensure "full pipe" operation.

18 26E The most common maintenance required by gate
valves IS oiling, tightening, or replacing the stem
stuffing box packing.

ANSWERS TO QUESTIONS IN LESSON 5

Answers to questions on page 308.

18.30A Gasoline engines may be used in water treatment
plants to drive pumps, generators, tractors, and
vehicles

18. JOB If a gasoline engine will not start, check the follow-
ing Items:

1 No fuel in tank, valve closed.

2 "arburetor not choked,

3 V/ater or dirt in fuel lines of carburetor,

4. Carburetor flooded,

5. Low compression,

6 Loose spark plug, and
7. No spark at plug.

18 30C A gasoline engine may not run properly du3 to:

1 Engine missmy,

2. Engine surging,

3. Engine stopping.

4. Engine overheating,

5. Engine knocking, and

6. Engine backfinng through carburetor.

Answers to questions on page 309.

1 8.30D If a gasoline engine will not start and the spark olug
IS wet with oil or fuel, this could indicate that the
cylinder is flooded with fuel by having the choke on
too long.

1 8 30E If a gasoline engine will not start and there is an oil
residue on the spark plug, this could indicate worn
piston rings.

1 8 30F After an engine has started, give it an opportunity to
warm up before applying the load.

Answers to questions on page 315.

18 31A Gasoline is not used as a fuel in diesel engines
because It would start to burn from the heat gener-
ated by compression before the piston reaches the
top of the stroke.

18.31B The four basic parts of a diesel fuel system are:

1. Primary fuel filter,

2. Secondary fuel filte*

3. Fuel Injection pump, and

4. Fuel injector.

18 31C The purpose of the fuel injection pun ^ is to deliver
fuel to ♦he injector at a very high pressure.

18.32A Heat Is removed from *Ue cylinders by a water
cooling system. Each cylinder Is surrounded with a
water jacket through which the coolant (water)
Circulates and pulls heat from the cylinder. This is
accomplished by a water pump that is belt-driven
from the crankshaft.

Answers to questions on page 316.

18.33A The storage and use of fuels for internal combus-
tion engines nust be in accordance with building
and fire marshal codes.

Maintenance 327

18.33B Four types of fuels commonly used by internal
combustion engines include (1) diesel, (2) gasoline,
(3) liquified petroleum gas (LPG), and (4) natural
gas.

18.34A Standby internal combustion engines not in regular
service should be started up and test run at least
once a week.

1 8.34B Standby engines should be test run long enough fcr
the engine to come up to its normal operating
temperature. If at all possible, the engine should be
run under its normal load

Answers to questions on page 321.

18.4A Information on how to operate, control and maintain
chemical feeders may be found in the feeder manu-
facturer's literature.

18.4B The three common types of chemical feeders are (1)
solid feeders, (2) liquid feeders, and (3) gas feeders.

18.4C Chlorine is toxic to humans and will cause corrosion
damage to equipment

18.4D Large chlonne leaks can be detected by smell. Small
leaks are detected by soaking a cloth with ammonia
water and holding the cloih near areas where leaks
might develop. A white cloud will indicate the pres-
ence of a leak.

Answers to questions on page 321

18.5A Tanks and reservoirs should be drained and inspect-
ed at least once every fjve years if the interior is well
protected: more often if it is not well protected.

1 8.5B The groundwater level should be below the bottom of
a tank before tt is drained so the tank will not float on
the groundwater when empty or develop cracks from
groundwater pressure.

18.5C Cathodic protection is an alternative to applying a
protective coating to prevent corrosion of a steel
tank.

Answers to questions on page 322.

18.6A A building maintenance program will keep the build-
ing in good shape and includes painting when neces-
sary. Attention also must be given to electncal sys-
tems, plumbing, heating, cooling, ventilating, floors,
windows, and roofs. The building should he kept
clean, tools should be stored in their proper place,
and essential storage should be available.

18.6B Factors that influence the type of building mainte-
nance program needed by a water treatment plant
include the age, type and use of each building.

OBJECTIVE TEST

Chapter 18. MAINTENANCE

Please mark correct answers on the answer sheet as
directed at the end of Chapter 1. There may be more than
one correct answer to the multiple choice questions.

TRUE-FALSE

1. An Equipment Service Card is another name for a
Service Record Card.

1. True

2. False

2. Building maintenace is NOT part of a treatment plant
operator's duties.

1. True

2. False

3. A treatment plant library should contain copies of the
plant's drawings and specifications.

1. True

2. False

4. Pumps in water treatment plants are driven only by
electric motors.

1. True

2. False

5. If a pump IS going to be shut down for a long period of
time, the pump should be drained.

1. True

2. False

6. An empty clear well drained for inspection purposes
could f oat up out of the ground when the groundwater
level IS high.

1. True

2. False

7 All gate valves have non-nsing valve stems.

1. True

2. False

8 The most practical form of emergency lighting is that
provided by standby power generators.

1. True

2. False

9 Standby power generators should be operated once a
week at full load.

1. True

2. False

ERLC

34J

328 Water Treatment

10 Diesel engines can use gasoline for fuel.

1. True

2. False

11 Diesel engines se spark plugs

1. True
2 False

12. A qualified electncian should perform most of the nec-
essary maintenance and repair of electncal equipment

1. True

2. False

13. When a pump is not snut off, locked out, and tagged
properly, a plant operator could be maintaining a pump,
the pump could start, and the operator cuuld lose a
finger.

1. True
2 False

14 Most electrical equipment does not indicate the proper
voltage on the name plate

1 True

2. False

15. Closing an electncal circuit is like closing a valve on a
water pipe.

1. True

2. False

MULTIPLE CHOICE

16 Which of the following items are parts of an electnc
motor?

1. Impeller

2. Rotor

3. Stator
4 Volute

5. Windings

17 Centnfugai pump parts mchide

1. Diaphragm.

2. Impeller

3. Piston

4. Rotor

5. Volute.

18. Wearing rings are installed in a pump to

1. Hold the shaft in position.

2. Keep the impeller in place.

3. Plug internal water leakage.

4. Wear instead of Impeller.

5. Wear out the sleeves.

19. What could be the cause of a pump's electnc motor not
starting?

1. Fuse or circuit breaker out

2. Incorrect power supply

3. No power supply

4. Pump not hooked to motor

5. Rotating parts of motor may be jammed mechanically

ERIC

20. Equipment name plate data must be recorded and filed
because the

1 Filing caoinet is supposed to have this information.

2 Information is needed to order replacement parts.

3 Manufacturer doesn't keep the information on older
models.

4 Name plate could become corroded.
5. Name plate could get lost

21 Compressor maintenance includes

1. Cleaning cylinder or casing fins weekly.
2 Examining the oil reservoir dipstick or sight glass.
3. Inspecting the suction filter of the compressor regu-
larly

4 Keeping the belts as tight as possible

5 Washing off the compressor weekly.

22 What IS the purpose of an equipment preventive mainte-
nance program'?

1 To extend equipment life.

2 To insure proper and efficient operation of the equip-
ment.

3. To keep operators looking at equipment.

4. To protect the public's investment spent buying the
equipment.

5. To provide jobs for operators when they visit a
facility.

23 When belts are used to dnve equipment, important
considerations include

1 . Belt dressing should be used monthly for pliability of
belts

2 Belts must be matched sets

3. Guaros are required on all belt drives that are ex-
posed.

4. Noise or squeal on startup can be corrected by
proper tension

5. Proper number of belts.

24 Some of the advantages of mechanical seals over
packing include

1. Continual adjusting, cleaning, o» repacking is not
required.

2. Lower initial cost.

3 Pump does not have to be dismantled for repair.

4 They last longer, thus resulting in labor savings.

5. Usually there isn't any damage to shaft sleeve when
they need replacing.

25 Wnat information must be on a warning tag attached to
a locked out switch?

1. Directions for removing tag

2. Name of company that printed tag
3 Name of equipment

4. Signature of person who locked out switch and who
IS only person authonzed to remove tag

5. Time to unlock switch

26 Operators should not do actual electncal repairs or
troubleshooting because

1 . Costly damage can be done to equipment by unauth-
onzed persons.

2. It IS too dangerous.

3. Many are not adequately trained

4. They realize their own limitations regarding electrical
work.

5. This IS a highly specialized field.

350

Maintenance 323

27. If a pump wiH not start, check for

1 . Loose terminal connections

2. Nuts, bolts, scrap iron, wood, or plastic in the wrong
places

3. Shaft binding or sticking

4. Tripped circuit breake s.

5. Water in the wet weh.

28. How can a chlonne leak be detected*^

1 . By an explosiometer

2. By checking the rotameter

3. By waving an ammonia-soaked rag

4. deen or reddish deposits on metal

5. Smell

29 What can heppen if you DO NOT penodical'y dram and
inspect plant tanks and channels?

1 . An emergency situation may develop dunng a period
of high demand.

2. Costly repairs could result.

3. Senous maintenance problems could develop.

4. The operator will not know if cracks are developing in
underground tanks and channels.

5. The operator will stay out of trouble.

30 Pump maintenance includes

1 . Checking operating temperature of bearings.

2. Checking packing gland.

3. Lubricating the impeller.

4. Operating two or more pumps of the same si/e
alternately to equalize wear.

5. Preventing all water seal leaks around packing
glands

31 Preventive ma.ntenance of electric motors includes

1. Checking temperature of motor.

2. Frequently starting and stopping the motor to give it
a rest.

3. Keeping motor free from dust, dirt and moisture.

4. Keeping motor outdoors where it can stay cool.

5. Lubricate bearings.

32. Maintenance of gate valve includes

1 . Lubricating bearing.

2. Lubricating with Prussian Blue.

3. Operating inactive valves to prevent sticking.

4. Refacing leaky valve seats.

5. Tightening or replacing the stem stuffing box pack-
ing.

34.

Proper selection of an emergency lighting unjt for a
particular location requires careful consideration of
which of the following items'^

1. Costs

2. Lighting requirements

3. Nearness of vendor to repair failures

4. Necessary switch gear

5. Type? of batteries

Possible causes of a gasoline engine not starting in-
clude

1.
2.
3.
4.
5.

Carburetor choked.
Carburetor floodea.
Loose spark plugs.
SparK at plug.

Water in fuel lines of carburetor.

ERIC

35. The ignition system for a gasoline engine consists of the

1 Battery

2. Coil.

3. Distnbutor

4. Filter

5. Thermostat.

36. If a compressor fails to operate or provide rated capac-
ity, what could be the cause of the problem*?

1 Air cleaner, cap and/or screen clogged

2 Air used by compressor is polluted

3. Engine fails to develop proper RPMs

4. Faulty oil seal

5. Pressure regulator improperly adjusted

37. Maintenance of automatic valves includes

1 Adjusting the check valve.

2 Cleaning any strainers in the pilot control system.
3. Determining if controls are properly positioning

valve.

If valve IS inactive, manually exercise valve from tight
shut to wide open position.
5 Reversing the flow through the valve.

38 Problems that may be encountered when storing gaso-
line include

1. Deterioration of gasoline stored for a iong time.

2 Easy starting of engines.

3 Gasoline leaking into an underground water supply.

4 Lack of gummy deposits on parts of the fuel system.

5 Water leaking into the gasoline storage tank.

39. Steel tanks may be protected from rusting by

1. Alternately wetting and drying walls.

2. Cathodic protection.

3 Maintaining humidity in tank

4 Protective coatings.

5 Washing tank walls.

40 Equipment service cards and service record cards
should

1. Identify the piece of equipment that the record card
represents.

2. Indicate the work done.

3 Indicate the work to be done.

4 Maintain selective service records.

5 Record sick leave.

41 Estimate the pumping capacity of a pump in gallons per
minute if 1 1 minutes are required for the water level in a
tank to drop 3 feet. The tank is 6 feet in diameter.

1 8GPM

2. 10GPM

3. 36 GPM
4 58 GPM
5. 74 GPM

42 Calculate the feed rate of a dry chemical feeder in
pounds per day if two pounds of chemical are caught in
a weighing tin dunng nine minutes.

1 . 320 lbs/day

2. 2394 lbs/day

3. 2670 lbs/day

4. 2660 lbs/day

5. 3200 lbs/day

35.1

CHAPTER 19

INSTRUMENTATION

Leonard Ainsworth

332 Water Treatment

TABLE OF CONTENTS

Chapter 19 Instrumentation

Page

OBJECTIVES 334

GLOSSARY 335

SYMBOLS 339

LESSON 1

19.0 Importance and Nature of Measurement and Control Systems 342

19.00 Need for Understanding Measurement and Control Systems 342

19.01 Importance to Waterworks Operator 342

19.02 Purpose and Naiu.c '^f the Measurement Process 342

19 03 Explanation of Control Systems 343

19.1 Safety Hazards of Instrumentation Work 345

19.10 Be Careful 345

19 11 Electrical Hazards 345

19 12 f\/1echanical Hazards . . 347

19 13 Vaults and Other Confined Spaces 348

19 14 Falls 348

19.2 Measured Variables and Types of Sensors/Transmitters 348

19.20 How Variables are Measured 348

19 21 Pressure 349

19 22 Level 349

19.23 Flow (Rate of Flow and Total Flow) 356

19.24 Chemical Feed Rate 360

19.25 Process Instrumentation 360

19.26 Signal Transmitters/Transducars 360

Instrumentation 333

LESSON 2

19.3 Categories of Instrumentation .... 363

19.30 Measuring Elements 363

19.31 Panel Instruments 363

19 310 Indicators . . 363

19 311 Indicators/Recorders 363

19 312 Recorders 364

19 313 Totalizers 367

19 314 Alarms 367

19.32 Automatic Controller 368

19.33 Pump Controllers 368

19.34 Telemetemg Links (Phone Lines) 369

19 35 Air Supply Systems 371

19 36 Laboratory Instruments 374

19.37 Test and Calibration Equipment 374

19.4 Operation and Preventive Maintenance 375

19.40 Proper Care of Instruments 375

19 41 Indications of Proper Function 375

19.42 Startup/Shutdown Considerations 378

19 43 Maintenance Procedures and Records 379

19.44 Operational Checks 379

19.45 Preventive Maintenance 379

19.5 Additional Reading 380

SUGGESTED ANSWERS

Chapter 19 INSTRUMENTATION

ANSWERS TO QUESTIONS IN LESSON 1

Answers to questions on page 343.

19.0A Measurement instruments can be considered an
extension of your human sens.^s because they Cc.n
perform the same duties as your eyes and ears can
directly.

19.0B Water treatment processes and equipment that
could be monitored or controlled by measurement
and control systems include influent and effluent
flows, basin levels, pump operation, chemical feed-
ers and filter valves.

1 9.0C An advantage of instruments over our senses is that
instruments provide quantities or measurable infor-
matio.i, whereas only qualitative information is avail-
able from our senses.

1 9.0D The anabg readout of an instrument has a pointer (or
other indicating means) that reads against a dial or
scale.

Answers to questions on page 345.

19.0E An on-off type "controller" controls the automatic
starting-stopping of a pump or a chemical feeder
motor.

19.0F Examples of "proportional control" in waterworks
operations include: (1) chlorine residual analyzer/
controller; (2) chemical feed, flow paced (open loop);
(3) pressure- or flow-regulating valves; (4) continu-
ous level control of filter basins; (5) variable-speed
pumping system for flow control.

19.0G The motor control station provides for on-off oper-
ation of electric motors.

Answers to questions on page 347.

19.1 A The general principles for safe performance on the
job are to ALWAYS avoid unsafe acts ana correct
unsafe conditions.

19 IB Electrical shock can cause death by asphyxiation
and/or burning.

19.1C An electrical "explosion" could shower you with mol-
ten metal, startle you into a bumped head or elbow,
or cause a bad fall.

Answers to questions on page 348.

19.1D Operators should be especially careful when working
around powered automatic mechanical equipment
because the equipment could start unexpectedly and
cause senous injury.

19,1E The purpose of an electrical lock-out device is to
positively prevent the operation of an electrical cir-
cuit, or to de-energize the circuit temporarily.

19 IF If electrical current flows through your upper body,
electrical shock could harm your heart and/or your
head.

19.1G Thin rubber or plastic gloves can be worn to reduce
markedly your chances of electrical shock.

Answers to questions on page 349.

19 2A A sensor is the primary element that measures a
vanable. The sensor is often a transducer of some
type that converts energy of one kind into some other
form to produce a readout or signal.

19.2B Pressure is measured by the novemen: of a f'axible
element or a mechanically deformable device sub-
jected to the force of the pressure being measured.

19.2C Some sensors are fitted with surging and overrange
protection to limit the effect of press^'re spikes or
water hammer on the sensor.

Answers to questions on page 355.

19 2D Liquid level sensors include floats, displacers.
probes, pressure sensors, and bubbler tubes.

19.2E A signal can be generated by a float element by
attaching the float to a steel tape or cable that is
wrapped around a drum or pulley. The level sensed
is transmitted as a signal (electrical) proportional to
the rotation (position) of the pulley or drum.

19-2F Probes are used instead of mechanical systems to
measure liquid levels in sealed or pressurized tanks,
or with chemicc.3ly-active liquids.

19.2G A bubbler measures the level of a liquid by sensing
(measuring) air pressure necessary to cause bubbles
to just flow out the end of the tube.

Answers to questions on page 360.

19.2H The two types of flow readings are (1) rate of flow
and (2) total flow (volume).

19 21 The two main types of larger flow measurement
devices are (1) velocity sensing and (2) differential-
pressu»'e sensing. Magnetic and ultrasonic devices
are also used.

19.2J Smaller service meters are one of the positive-
displacement types of total flow meters.

19.2K Velocity-sensing devices measure flows by sensing
the rate of rotation of a special impeller placed within
the flowing system.

19.2L Flows are measured with ventun meters by sensing
the pressure differential between the water pressure
l^efore the restnction in the meter or tube, and the
pressure within the restriction.

Answers to questions on page 362.

19.2M Chemical feed rates are measured on a weight or
volumetric basis if the chemical is in a dry solid form.
If chemical is in liquid form, ^ volumetric flow device
such as a rotameter may be used.

19.2N Process variables commonly measured and/or con-
trolled by instruments include turbidity, pH, chlorine
residual, fluoride, electrical conductivity, hardness,
alkalinity and temperature.

19.20 Values measured at one site are transmitted by a
signal to a receiver at a remote location.

403

382 Water Treatment

19. 2P The two general systems used to transmit measure-
ment signals are electrical and pneumatic systems.

ANSWERS TO QUESTIONS IN LESSON 2

Answers to questions on page 364.

19.3 A The purpose of indicators is to give a visual presen-
tation of a variable's value, either as an analog cr as
a digital display.

19.3B An analog display uses some type of pointer (or
other indicator) against a scale.

19.3C Recorders are usually found in a central location at a
water treatment plant.

19.3D Factors that can cause electronic instrument prob-
lems include temporary power failures, tripped panel
circuit breakers, voltage surges (or lightning) result-
ing in blown fuses, and excessive heat.

Answers to questions on page 368.

19.3E Recorders are indicators designed to show how the
value of the variable has changed with time,

19.3F Recorder charts may be circular or strip types.

19.3G In remote locations where no electricity is available,
charts are driven by hand-v/ound drives or batteries.

19.3H Alarms may produce either visual and/or audible
signals.

Answers to questions on page 369.

19.31 An operator might bypass a proportional-type con-
troller in an emergency or when, in the judgment of
the operator, the controller is not exercising control
within sensible limits. To bypass a controller, switch
to the manual mode of operation.

19.3J "On-off" controls should be programmed to operate
or cycle associated equipment on and off no more
often than actually necessary for plant or system
operation.

19.3K Pumps can be prevented from running -jpon loss of
signal by electrical circuitry designed so the pump
will turn OFF on an OPEA/ signal circuit and OA/ only
with a CLOSED circuit.

19.3L Pumps in a pump station can be operated for si.milar
lengths of time by the use of manual or automatic
"sequencers" which switch different pumps to the
"lead" pump position and the other(s) to the "lag"
position periodically.

Answers to questions on page 374.

19.3M Signals are transmitted over long distances by the
use of signal tra'^smission lines. These lines may be
wires owned by the water agency, or telephone lines
leased from the local telephone agency. Radio or
microwave transmission is sometimes used.

19.3N A loss of signal causes the indicator to go to zero or
to maximum scale, depending on type of signal.

19.30 Pneumatic instrumentation pressure systems must
have a constant source of clean, dry, pressurized air
for reliable operation.

19.3P Oil is removed by filtration through special oil-absor-
bent elements, and a dryer desiccator or refrigera-
tion is used to remove moisture from instrument air.

ERLC

Answers to cjestions on page 374.

19.30 Care must be exercised when working in the labora-
tory so as not to break t.he sensitive instruments,
delicate equipment, or fragile glassware,

19.3R Operators should become familiar with the testing
and calibration of plant measuring and control sys-
tems in order to assist instrument technicians, and to
better understand the plant's instrumentation sys-
tem. Also, development of skills in instrument testing
and calibration equipment may result in a job promo-
tion and/or pay raise.

19.3S V-O-M stands for Volt-Ohm-Milliammeter, conrnonly
referred to as a multi-meter.

Answers to questions on page 375.

19.4A The three principles which are the keys to proper
instrument 0 & M are:

1. Recognizing properly functioning instruments, so
as to prevent prolonged and damaging malfunc-
tions,

2. Shutting down and preparing devices for seasons
or prolonged nonoperation, and

3. Performing preventive (and minor corrective)
maintenance tasks to ensure proper operation in
the long term.

19.4 B General tasks expected of operators of instrumenta-
tion systems can be summed up (1) from an oper-
ations standpoint as learning and constant attention
to what constitutes normal function, and (2) from a
maintenance standpoint, as ensuring proper and
continuing protection and care of each component.

Answers to questions on page 378.

19.40 Three signs tiiat a flow recorder may not be function-
ing properly are:

1. Very flat or steady pen trace (is the system
working at all. or is the variable really that con-
stant?);

2. Excessive pen/pointer quiver (causes undue wear
on parts, can usually be adjusted out); and

3. Constant or periodic hunting, or spikes, in a pen/
pointer (improper adjustment, control or other
problem).

19.40 Recording pens are most hkely to become stuck or
"hung-up" on the chart edge or in a tear or hole.

19.4E A common reason for nonoperation of a pneumatic
system is the failure of the instrument air supply
caused by water and oil.

19.4F An indication of a serious problem in an electrical
instrument or power cicuit is the presence of smoke
and/or a burning odor.

Answers to questions on page 379.

19.4G Moisture can be controlled in instruments by a
space-heat source (such as a power transformer) or
by inserting a container of desiccant into its case.

19.4H Pneumatic instrumentation should be purged with
dry air before shutdown to rid the individual parts of
residual oil and moisture and to minimize internal
corrosion.

Answers to questions on page 379.

19.41 Regular preventive maintenance duties should be
printed on forms or cards for use by operators as a

404

Instrumentation 383

reminder, guide and record of preventive mainte«
nance.

1 9.4J Operational checks are performed by always observ-
ing each system for its continuing signs of norma!
operation, and cycling some indicators by certain
testing methods.

19.4K If a recorder trace is altered from its usual pattern
dunng the process of checking an instrument, the
operator causing the upset should initial the chart
appropriately, with the time noted.

Answers to questions on page 380.

19.4L To obtain a technical manual for an inst^'ument, write
to the manufacturer. Be sure to provide all relevant
serial/model numbers in your request to the manu-
facturer for a manual.

19.4M Instrument supplies and spare parts that should
always be available include charts, pens, pen clean-
ers and ink, and any other parts necessary for
Instrument operation or service.

OBJECTIVE TEST

Chapter 19. INSTRUMENTATION

Please wnte your name and mark the correct answers on
the answer sheet as directed at the end of Chapter 1 . There
may be more than one correct answer to the multiple choice
questions.

TRUE-FALSE

1 . Accuracy cf an instrument relates to the closeness of a
measurement to the actual value.

1. True

2. False

2. A digital readout display provides a direct, numerical
reading.

1. True

2. False

3. A motor control station provides for the on-of f operation
of an electric motor.

1. True

2. False

4. The pressing down of a relay armature within an electri-
cal panel may cause an electncal "explosion" to shower
you with molten metal.

1. True

2. False

5. A danger may exist around powered mechanical equip-
ment even when the exposed rotating or meshing
elements have "guards" fitted in compliance with safety
regulations.

1. True

2. False

6. Power tools are often used to calibrate instruments.

1. True

2. False

7. Falls are a leading c'luse of lost-tirrie accidents.

1. True

2. False

8. A measured variable is that quantity which is sensed
and quantified by a primary element or sensor.

1. True

2. False

9. Pressure is sensed by mechanically immovable ele-
ments.

1. True

2. False

10. Use of a bubbler tube is a very precise method of
measuring water levels.

1. True

2. False

11. When propeller meters become old, they become sus-
ceptible to over registration (read hiyh).

1. True

2. False

12. The permanent pressure loss through a venturi meter is
greater than *.TOugh an orifice plate.

1. True

2. False

1 3. Pneumatic signal systems are commonly used over very
long distances.

1. True

2. False

14. Operators may safely rely solely upon the readings of
instruments to ensure proper plant operation.

1. True

2. False

15. Alarms are visual and/or audible signals that a variable
is out of bounds.

1. True

2. False

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4o:;

384 Water Treatment

1 6. Several different tone signals can be sent over the same
pair of phone lines.

1. True

2. False

17. A remote sensing and control station can send tone
signals to the water plant and simultaneously receive
tone signals to effect control at the site ove. the same
!ines.

1. True

2. False

18. "Pneumatics" may operate for many years without sig-
nificant problems if they have a quality air supply.

1. True

2. False

19. "Plant air" must be filtered and dried, as with "instrument
air."

1. True

2. False

20. If a gentle tap on an instrument causes a slight pen
movement, the instrument is functioning properly.

1. True

2. False

which controls or adjusts the process variable.

1. Control loop

2. Control system

3. Feedback

4. Linearity

5. Telemetry

26 Which of the following items are safety provisions that
may be used on electrical equipment?

1. Insulating covers

2. Lockouts

3. Safety switches
<4. Torque ratings
5. Warning labels

27. When working on instruments while standing on a
ladder, you should

1. Carry tools on an electrician's belt.

2. Leave tools on the ladder steps when not working.

3. Use a non-conductive type of ladder.

4. Wear a hard hat.

5. Wear thin rubber or plastic gloves.

28. Pressure is measured or sensed by

1. Bourdon tubes.

2. Bellows.

3. Diaphragms.

4. Pistons.

5. Propellers.

MULTIPLE CHOICE

21. Objectives of this chapter include how to

1. Determine location and cause of measurement and
control system failures.

2. Dismantle an automatic controller and repair it.

3. Safely enter a vault without any ventilation system.

4. Test an electrical circuit with a screwdriver.

5. Use power tools in wet environments.

22. Operators should be able to

1. Dram an air line.

2. Free a stuck pen.

3. Repair a turbidimeter.

4. Replace a fuse.

5. Restore proper control of a controller.

23. refeis to how closely an instrument measures

the actual value of the process variable being meas-
ured.

1. Accuracy

2. Calibration

3. Precision

4. Repeatability

5. Standardization

24. Examples of proportional control encountered by water-
works operators include

1. Chemical feed, flow paced.

2. Chlorine residual analyzer/controller.

3. Continuous level control of filter basins.

4. Flow regulating valves

5. Pressure regulating valves.

25. is the circulating action between the sensor

which measures a process variable and the controller

ERIC

29. are used to measure the level of water.

1. Bubblers

2. Displacers

3. Electrical probes

4. Floats

5. Stilling wells

30. Velocity may be sensed

1. Chemically

2. Electrically

3. Hydraulically

4. Mechanically

5. Naturally

31. Flow measuring devices include

1. Impellers.

2. Orifice niates.

3. Propellers.

4. Rotameters.

5. Venturis.

32. Which of the following process variables are usually
monitored continuously by instrumentation in a modern
water treatment plant?

1. Chlorine residual

2. Cohforms

3. Iron and manganese

4. pH

5. Turbidity

33. Advantages of digital panel indicators include

1. Cheaper than analog.

2. Erroneous values easily recognized.

3. Quickly read.

4. Respond virtually instantly to variable change.

5. Rugged.

406

Instrumentation 385

34. Causes of electronic instrument problems include

1 . Dirty instrument air.

2. Excessive heat.

3. Temporary power failure.

4. Tripped panel circuit breakers.

5. Voltage surges.

35. Controls available to protect pumps from damage in-
clude

1. High-pressure cut-off switches.

2. Lock-out switches.

3. Low-pressure cut-off switches.

4. Sensors that detect open or closed signal circuits.

5. Warning tags.

36. Reliable operation of pneumatic instrumentation pres-
sure system requires

1. Clean air.

2. Dry air.

3. Pressurized air.

4. Properly lubricated air.

5. Uninterrupted power.

Essential parts of a plant's instrument air supply system
include

1. Air filters.

2 Air dryers.

3. Compressors.

4. Compressor controls.

5. Master air pressure regulators.

38. Erratic performance by pneumatic instruments may be
caused by

1. Carbon dioxide in the air supply.

2. Excessive temperature of air supply.

3. Oil in air supply.

4. Over-pressurized air supply.

5. Water in air supply.

39. An operator should be alert for which of the pen
movements that could indicate a ootential problem*?

1. Constant hunting

2. Periodic spikes

3. Quivering pen movement

4. Similar cycles

5 Very flat pen trace

40. Recording pens may get stuck on or in

1. Chart edges.

2. Chart ends.

3. Holes.
4 Ink.

5. Tears.

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407

CHAPTER 20

SAFETY

Joe Monscvitz

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388 Water Treatment

TABLE OF CONTENTS

Chapter 20. Safety

Page

OBJECTIVES

391

GLOSSARY

392

LESSON 1

20.0 Responsibilities

o9w

20.00 Everyone Is Responsible for Safety 3g3

20.01 Regulatory Agencies

20.02 Utilities

393

20.03 Supervisors

394

20.04 Operators

394

20.05 First Aid

395

20.06 Reporting

20.07 Training

20.08 Measuring

o99

20.09 Human Factors

400

LESSON 2

20.1 Chemical Handling

20.10 Safe Handling of Chemicals

20.11 Acids

402

20.110 Acetic Acid (Glacial)

20.1 1 1 Hydrofluosilicic Acid

20.112 Hydrofluoric Acid

20.113 Hydrochloric Acid ^^3

20.114 Nitric Acid

405

20.115 Sulfuric Acid

405

20.12 Bases

405

20.120 Ammonia

406

20.121 Calcium Hydroxide

20.122 Sodium Hydroxide (Caustic Soda) 4Q7

Safety 389

20.123 Sodium Silicate "^07

20.124 Hypochlorite

20.126 Sodium Carbonate

20.13 Gases

20.130 Chlorine (Cy

20.131 Carbon Dioxide (CO2)

20.132 Sulfur Dioxide (SO2)

20.14 Salts

20.140 Aluminum Sulfate (alum)

20.141 Ferric Chloride

20.142 Ferric Sulfate

20.143 Ferrous Sulfate

20.144 Sodium Aluminate ^'•^

20.145 Fluoride Compounds ^"'^

2015 Powders

20.150 Potassium Permanganate (KMnOJ

20.151 Powdered Activated Carbon

20.152 Other Powders

20.16 Chemical Storage Drains ^"^^

LESSON 3

20.2 Fire Protection

20.20 Fire Prevention

20.21 Classification

20.22 Extinguishers

20.23 Fire Hoses

20.24 Flammable Storage

20.25 Exits

20.3 Plant Maintenance

20.30 Maintenance Hazards ^20

20.31 Cleaning "^20

20.32 Painting ^20

20.33 Cranes

20.34 Manholes ^21

20.35 Power Tools ^21

20.36 Welding "^22

20.37 Safety Valves ^22

20.4 Vehicle Maintenance and Operation ^23

20.40 Types of Vehicles ^23

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390 Water Treatment

20.41 Maintenance

20.42 Seat Belts

20.43 Accident Prevention

20.44 Forklifts

LESSON 4

20.5 Electrical "Equipment . . .

20.50 Electrical Safety

20.51 Current — Voltage

20.52 Transformers

20.53 Electrical Starters

20.54 Electrical Motors . .

20.55 Instrumentation

20.56 Control Panels

20.6 Laboratory Safety

20.60 Laboratory Hazards

20.61 Glassware

20.62 Chemicals

20.63 Biological Considerations

20.64 Radioactivity

20.65 Laboratory Equipment

20.650 Hot Plates

20.651 Water Stills

20.652 Sterilizers

20.653 PIpet Washers
20J Operator Protection

20.70 Operator Safety

20.71 Respiratory Protection

20.72 Safety Equipment . .

20.73 Eye Protection

20.74 Foot Protection

20.75 Hand Protection

20.76 Head Prelection

20.77 Water Safety

20.8 Preparation For Emergencies

20.9 Arithmetic Assignment

20.10 Additional Reading
Suggested Answers
Objective Test

OBJECTIVES

Chapter 20. Safety

Following completion of Chapter 20, you should be able
to:

1. List the responsibilities of all persons and agencies
involved in waterworks safety,

2. Identify ana safely handle hazardous chemicals,

3. Recognize fire hazards and properly extinguish various
types of fires,

4. Safely maintain waterworks equipment and facilities,

5. Properly operate and maintain vehicles,

6. Recognize electrical hazards,

7. Safely perform duties in a laboratory, and

8. Protect other operators and yourself while working in and
around waterworks facilities.

392 Water Treatment

GLOSSARY

Chapter 20. SAFETY

DECIBEL (DES-uh-bull) DECIBEL

A unit for expressing the relative intensity of sounds on a scale from zero for the average least perceptible sound to about 130
for the average level at which sound causes pain to humans.

OLrACTORY FATIGUE (ol-FAK-tore-ee) OLFACTORY FATIGUE

A condition in which a person's nose, after exposure to certain odors, is no longet able to detect the odor.

OSHA Q^^^

The Williams-Stelger Occupational Safety and Health Act of 1970 (OSHA) is a law designed to protect the health and safety of
industrial workers and also the operators of water supply systems and treatment plants.

TAILGATE SAFETY MEETING TAILGATE SAFETY MEETING

The term TAILGATE comes from the safety meetings regularly held by the construction industry around the tailgate of a truck.

413

Safety 393

CHAPTER

(Lesson 1

20.0 RESPONSiBILITIES

20.00 Everyone Is Responsible for Safety

Waterworks utilities, regardless of size, must have a
safety program if they are to realize a low frequency of
'"ccideht occurrence. A safety program also provides a
means of comparing frequency, disability and severity with
other utilities. The utility should identify causes, provide
training, have means of reporting, and hold supervisors
responsible for the program implementation. Each utility
should have a safety officer or supervisor evaluate every
accident, offer recommendations, and keep and apply statis-
tics. The c*fectiveness of any safety program will depend
upon how the utility holds its supervisors responsible. If the
utility hclds only the safety officer or the employees respon-
sible, the program will fail. The supervisors are key in any
organization. If they disregard safety measures, essential
parts of the program Wh lot work. The results will be an
overall poor safety record. After all, the first line supervisor
IS where the work is being performed, and some may take
advantage of an unsafe situation in order to get the job
completed. The organization must discipline such supervi-
sors and make them aware of their responsibility for their
own and their operators' safety.

Safety is good business both for the operator and the
agency. For a good safety record to be accomplished, all
individuals must be educated and must believe in the pro-
gram. All individuals involved must have the conviction that
accidents can be prevented. The operations should be
studied to determine the safe way of performing each job.
Safety pays, both in monetary sav ings and in happiness of
the operating staff.

20.01 Regulatory Agencies

There are many state and federal agencies involv<>'J in
ensuring safe working conditions. The one law that has had
the greatest impact has been the Occupational Safety and
Health Act ot 1970 (OSHA), Public Law 91-596, which ♦^ok
^'^zX on December 29, 1970. This legislation affect: more

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20. SAFETY

of 4 Lessons)

than 75,000,000 employees and has been the basis for most
of the current state laws covering employees. Also, many
state regulatory agencies enforce the OSHA requirements.

The OSHA regulations provide for safety inspections,
penalties, recordkeeping and variances. Supervisors must
understand the OSHA Act and must furnish each operator
With the rules of conduct in order to comply with occupation-
al safety and health standards. The intent of the regulations
IS to create a place of employment which is free from
recognized hazards that could cause serious physical harm
or death to an operator.

Civil and criminal penalties are allowed under the OSHA
Law, depending upon the size of the lousiness and the
seriousness of ^^e violation. A routine violatio" could cost an
employer or supervisor up to $1,000 for each violation. A
serious, willful or repeated violation could cause the c mploy-
er or supervisor to be assessed a penalty of not more than
$10,000 for each violation. Penalties are assessed against
the supervisor responsible for the injured operator. Opera-
tors should become familiar with the OSHA regulations as
they apply to their organizations. They mu^^t correct viola-
tions and prevent others from occurring.

20.02 Utilities

Water utilities must make safety a part of management's
responsibility. Each utility should start and maintain a safety
program by holding its supervisors responsible for the
elfectiveness of the program. The utilities must have a
reporting system to keep records; they may be required to
submit reports to state and federal agencies. Even if the
utility does not submit reports to other agencies, it should
keep and review such reports on its own, as a means of
reducing hazards to the operators.

Each utility should develop policy statements on safety,
giving its objective concerning the operator's welfare (Table
20.1). The statement should be brief, but express the utility's
recognition of the need for safety to stimulate efficiency,
improve service, imp^'Ove morale and to .naintain oood

414

394 Vi^ei^ Treatment

public relPtions. ^he poiicy should recognize the human
factor (the unsafe act) as the most slgnificent cause of
accidents, and thereby emphasize the operator's responsi-
bility to perform the job safely. The policy should be one of
providing the operators with proper equipment and safe
working conditions. Finally, it is essential that the policy
reinforce the supervisory responsibility to maintain safe
work practices

This policy statement should be made by every utility
regardless of size. The statement should be written and
given to each operator and all other employees and rein-
forced by the supervisory staff. Without such an objective,
the utility cannot hope to gain the loyalty and respect of its
operators, nor can it achieve efficient plant operation. The
utility must hold everyone responsible for safety and desig-
nate a specific indi\/idual to be responsible for an active, on-
going safety program.

TABLE 20.1 SAFETY POLICY STATEMENT

LAS VEGAS VALLEY WATER DISTRICT
SAFETY STATEMENT WORK RULE #920

The Distnct recognizes its responsibility for providing the
safest working conditions for its employees and customers.
This responsibility is met by means of a safety program
which will be applied through the development of safety
awareness among the t nployees. the use of up-to-date
safety equipment, and the continual inspection of conditions
and practices by all levels of supervision.

It IS the responsibility of everv emplo/ee to develop safe
working hibits. The development of proper attitudes toward
safety is the only method to improve safe working habits.
Therefore, training sessions play a large part in the safety
program. The District wants to protect all employees and the
public from injury and accidents. To accomplish this goal,
the safety program will involve everyone, and it will require
the active participation and cooperation of all to make it
operate effectively.

Safety training sessions are conducted for all Dl<itrict em-
ployees and employees are expected to perform in a safe
manner Negligent or unsafe conduct by an employee will
subject the employee to disciplinary action.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 438.

20.0A Wha* ihould be the duties of a safety office-'?

20.0B Who should be responsible for the iinpiemenL tion of
a safety program?

20.0C Who enforces the OSHA requirements'?

20 OD What should be included in a utility's policy statement
on safety?

thereby effectively ensure compliance with all aspects of the
utility's safety program.

The problem, however, is one of tne supervisor accepting
this responsibility. The supervisor vho wishes to complete
the job and go on to the next one without taking time to be
concerned about working conditions, the welfare of opera-
tors, or considenng any aspects of safety is a poor supervi-
sor. Only after an accident occurs will a careless supervisor
question the need t,ir a work program based on safety. At
this point, however, it is too late, and the supervisor may be
tempted to simply cover up past mistakes. As sometimes
happens, the supervisor may even be partially or fully
responsible for the accident by causing unsafe acts to take
place, by requiring work to be performed in haste, by
disregarding an unsafe work environment or by overlooking
or failing to consider any number of safety hazards. This
negligent supervisor could be fined, sentenced to a jail term,
or even De barred from working In the profession.

All utilities should make their supervisors bear the great-
est responoibllity for safety and hold them accountable for
planning, implementing and controlling the safety program.
If most accidents are caused and do not just happen, then It
IS the supervisor who can help prevent most accidents.

Equally important are the officials above the supervisor.
These officials Include commissioners, managers, public
works directors, chief engineers, superintendents and chief
operators. The person In responsible charge for the entire
agency or operation must believe In the safety program. This
peroon must budget, promote, support and enforce the
safety program by vocal and visible examples and actions.
The top person's support is absolutely essential for an
effective safety program.

20.04 Operators

Each operator also shares in the responsibility for an
effective safety program. After all. operators have the most
to gam since they are the most likely victims of accidents. A
review of accident causes shows that the accident victim
often has not acted responsibly. In toiDe way the victim has
not complied with the safety regulations, has not been fully
aware of the working conditions, has not been concerned
about fellow employees, or just has not accepted any
responsibility for the utility's safety program.

Each operator must accept, at least in part, responsibility
for fellow operators, for the utility's equipment, for the
operator's own welfare, and even for seeing that the super-
visor complies with established safety regulations. As point-
ed out above, the operator has the most to gain. If the
operator accepts and uses unsafe equipment, it is the
operator who is in danger if something goes wrong. If the
operator fails to protect the other operators, it is the opera-
tor who must make up the work lost because of injury. If
operators fail to consider their own welfare, it is they who
suffer the pain of any injury, the loss of income, and maybe
even the loss of life.

20.03 Crupervisors

The success of any safety program will depend upon how
the supervisors of the utility t/jew their responsibility. The
supervisor who has the responsibility for directing work
activities must be safety conscious. This supervisor controls
the operators' general environment and work habits and
influences whethe; or not the operators comply with safety
regulations. The supervisor Is In the best position to counsel.
Instruct and review the operators' working methods and

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41:3

Safety 395

The operator must accept responsibility for an active role
in the safety program by becoming aware of the utility's
safety policy and conforming to established regulations
THE OPERATOR SHOULD ALWA YS CALL TO THE SUPER-
VISOR'S ATTENTION UNSAFE CONDITIONS, environment,
equipment or other concerns operators may have about the
work they are performing. Safety should be an essential part
of the operator's responsibility.

20.05 First Aid

By definition, first aid means emergency treatment for
injury or sudden illness, before regular medical treatment is
available. Everyone in an organization should be able to give
some degree of piompt treatment and attention to an injury.

First aid training m the basic principles and practices of
life-saving steps that can be taken in the early stages of an
injury are available through the local Red Cross, Heart
Association, local fire departments and other organizations.
Such training should periodically be reinforced, so that the
operator has a complete understanding of water safety,
cardio-pulmonary resuscitation (CPR) and other life-saving
techniques. All operators need training 'n first aid, but it is
especially important for those who regularly work with
electrical equipment or must handfa chlorine and other
dangerous chemicals.

First aid has little to do with preventing accidents, but it
has an important bearing upon the survival of the injured
patient. A well-equipped first aid chest or kit is essential for
proper treatment. The kit should be inspected regularly by
the safety officer to a&sure that supplies are available when
needed. First aid kits should be prominently displayed
throughout the treatment plant and in company vehicles.
Special consideration must be given to the most hazardous
areas of the plant such as shops, laboratories, and chemical
handling facilities.

Regardless of size, each utility should establish standard
operating procedures (SOP) for first aid treatment of injured
personnel. All new operators should be instructed in the
utility's first aid program.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 438.

20.0E How could a supervisor be responsible for an acc-
dent?

20.0F What types of safety-re'ated responsibilities must
each operator accept?

20.0G What is first a«d?

20.0H First aid training is most important for operators
Involved In what types of activities'?

20.06 Reporting

The mainstay of a safety program is the method of
reporting and keeping of statistics, These records are need-
ed regardless of size of the utility, as they provide a means
of identifying accident frequencies and causes as well as the
personnel involved. The records can be looked upon as the
operator's safety report card. Therefore, it becomes the
responsibility of each injured operator to fill out the utility's
accident report.

All injuries snould be reported, even if they are minor in
nature, so as to establish a record in case the injury

develops into a senous injury, it may be difficult at a later
date to prove the accident did occur on the job and have the
utility accept the responsibility for costs. The responsibility
for reporting accidents affects several levels of personnel.
First, of course, is the injured person. Next, it is the respon-
sibility of the supervisor, and finally, the

Accident report forms may be very simple. However, they
must record all details required by law and all data needed
for statistical purposes. The forniS shown here in Figures
20.1 and 20.2 are examples for you to consider for use in
your plant. The report must show the name of the injured,
employee number, divisior:, t,me of accident, nature of
in; jry, cause of accident, first aid administered, and remarks
for Items not covered elsewhere. There should be a review
process by foreman, supervisor, safety officer, and manage-
ment. RECOMMENDATIONS ARE NEEDED AS WELL ASA
FOLLOW-UP REVIEW TO BE SURE THAT PROPER AC-
TION HAS BEEN TAKEN TO PREVENT RECURRENCE. In
addition to reports needed by the utility, there are other
reports that may be required by state or federal agencies.
For example, vehicle accident reports must be submitted to
local police departments. If a member of the Public is injured,
additional forms are needed because of possible subse-
quent claims for damages. If the accident is one of occupa-
tional injury, causing lost time, other reports may be re-
quired. Follow-up investigations to identify causes and
responsibility may require the development of other specific
types of record forms.

In the preparation of accident reports, it is the operator's
responsibility to correctly fill out each form, giving complete
details. The supervisor must be sure no information is
overlooked which may be helpful in preventing recurrence.

4afeiM Officer rc\\cw
coy^^ti\c agii^nt^ ^di make

In day-to-day actions, operators, supervisors and man-
agement often overlook opportunities to counsel individual
operators in safety matters. Then, when an accident occurs,
they are not inclined to look too closely at accident reports.
First, the accident is a series of embarrassments, to the
injured person, to the supervisor and to management.
Therefore, there is a reluctance to give detailed consider-
ation to accident reports. However, if a safety program is to
function well, it will require a thorough effort on the part of
the operator, supervisor and management in accepting their
responsibility for the accident and making a greater effort
through good reporting to prevent future similar accidents.
Accident reports must be analyzed, discussed, and the real
cause of the accident identifiec and corrected.

Emphasis on the prevention of future accidents cannot be
overstressed. We must identify the caust- of accidents and
implement whatever measures are necessary to protect
operators from becoming injured.

41'6

396 Water Treatment

Date .

Name of injured employee .
Date of accident

Location of accident .
Name of doctor

Name of hospital .

Witnesses (name & address) .

. Time .

Employee #

Employee's Occupation .
Nature of injury

. Address .
. Address.

. Area .

PHYSICAL CAUSES
Indicate below by an 'X whether in your opinion, the accident was caused by:

Improper guarding

Defective substances or equipment

Hazardous arrangement

Improper Illumination

Improper dress or apparel

No mechanical cause

Not listed (describe briefly)

Working methods
Lack of knowledge or skill
Wrong attitude
Physical defect

UNSAFE ACTS

Sometimeb the »njured person is not directly associated with the causes of an accident. Using an "X" to represent the injured
worker and an "O" to represent any other person involved, indicate whether, in your opinion, the accident was caused by:

Operating without authority

Failure to secure or warn

Working at unsafe speed

Make safety device inoperative

Unsafe equipment or hands instead of equip.

No unsafe act

Not listed (describe briefly)

Unsafe loading, placement & etc.

Took unsafe position

Worked on moving equipment

Teased, abused, distracted & etc.

Did not use safe clothing or personal
protective equipment.

What job was the employee doing?

What specific action caused the accident'^

What steps will be taken to prevent recurrence'?

Date of Report .

. Immediate Supervi^^or.

Comments:

REVIEWING AUTHORITY
Comments:

ERIC

Safety Officer Department Director
Fig. 20.1 Supervisor's accident report

41 V

Date

Safety 397

INJURED: COMPLETE THIS SECTION

Name .

Address .
Title

Place of Accident

Street or Intersection
Date

Type of Job You Were Doing When Injured

Dept Assigned.

Hour.

Age.

.Sex .

. Marital Status .

A.M.

. P.M.

Object Which Directly Injured You

Part of Body Injured

How Did Accident Happen'? (Be specific and give details; use back of sheet if necessary).

DiJ You Report Accident or Exposure at Once? (Exp'ain "No") Yes □ No □

Did You Report Accident or Exposure to Supervisor?
Give Name

YesD

NoD

Were There Witnesses to Accident or Exposure'?
Give Names

Y3sn

NoD

Did You See a Doctor? Nf Yes. fiive Name)

YesD

NoD

Are You Goina to See a Doctor'? (Give NJamp)

YesD

NoD

Date Signature

SUPERVISOR: COMPLETE THIS SECTION — (Beto'n to Personnel as soon as Possible)

,^as an Investigation of Unsafe Conditions and/or
Unsafe Acts Made'? If Yes, Please Submit Copy.

YesD

NoD

Was Injured Intoxicated or Misconducting
Himself at Time of Accident? (Explain "Yes")

YesD

NoD

Date Disability Last Day Date Back
Commenced Wages Earned on Job

Date Report Completed ^ 19 Signed By

Title

Oistfibutton • Canary • Department Head. Pmk • Supervisor. White • Personnel

Fig, 20,2 Accident report

ERIC - 418

398 Water Treatment

20.07 Training

If a safety program ts to ever work well, management will
have to accept responsibility for the following three compo-
nents of training:

1 . Safety education of all employees,

2 Reinforced education in safety, and

3. Safety education in the use of tools and equipment.

Or to put It another way, the three most important controlling
factors in safety are education, education and education.

Responsibility for overall training must be that of upper
management. A program that will educate operators and
then reinforce this education in sa'ety must be planned
systematically and promoted on a continuous basis. There
are many avenues to achieving this goal.

The safety education program should start with the new
operator. Even before employment, verify the operator's
past record and qualifications and review the pre-employ-
ment physical examination. In the new operator's orienta-
tion, include instruction in the importance of safety at /our
utility or plant. AJso discuss the matter of proper reporting of
accidents as well as the organization's policies and prac-
tices. Give new operators copies of all safety SOP's and
direct their attention to parts that directly involve them. Ask
the safety officer to give a talk about utility policy, safety
reports and past accidents, and to orient the new operator
toward the importance of safety to operators and to the
organization.

The next consideration must be one of training the new
operator in how to perform assigned work. Most supervi-
sors think in terms of On-the-Job Training (OJT). However,
OJT is not a good way of preventing accidents with ah
inexperienced operator. The idea is all right if the operator
comes to the organization trained in how to perform the
work, such as a treatment operator from another plant. Then
you only need to explain your safety program and how your
policies affect the new operator. For a new operator who is
inexperienced in water treatment or in utility operation, the
supervisor must gi^e detailed consideration to the opera-
tor's welfare. In this instance, the training should include not
only a safety talk, but the foreman (supervisor) must train the
inexperienced operator in all aspects of treatment plant
safety. This training includes instruction in the handling of
chemicals, the dangers of electrical apparatus, fire hazards,
and proper maintenance of equipment to p''event accidents.
Special instructions will also be needed for specific work
environments such as manholes, gases (chlorine and hydro-
gen sulfide (HgS)), water safety, and any specific hazards
thai are unique to your facility. The new operator must be
checked out on any equipment personnel may operate such
as vehicles, forklifts, valve operators, and radios. All new
operators should be subjected to a safety orientation pro-
gram during the first few days of their employment, and an
overall training program in the first few months.

The next step in safety education is reinforcement. Even if
the operator is well trained, mistakes can occur; therefore,
the education must be continual. Many organizations use
the "tailgate" method as a means of maintaining the opera-
tor's interest in safety. The program should be conducted by
the first line supervisor. Schedule the informal tailgate
meeting for a suitable location, keep it short, avoid distrac-
tions and be sure that everyone can hear. Hand out litera-

ture, if available. Tailgate talks should communicate to the
operator specific considerations, new problems, and acci-
dent information. These topics should be published. One
resource for such meetings can be those operators who
have been involved in an accident. Although it is sometimes
embarrassing to the injured, the victim is now the expert on
how the accident occurred, what could have been done to
prevent it, and how it felt to have the injury. Encourage all
operators, new and old, to participate in tailgate safety
sessions.

Use safety posters to reinforce safety training and to
make operators aware of the location of dangerous areas or
show the importance of good work habits. Such posters are
available through the National Safety Council's catalog.^
Awards for good safety records are another means of
keeping operators aware of the importance of safety. The
awards could be given to individuals in recognition of a good
safety record. Publicity about the awards may provide an
incentive to the operators and demonstrates the organiza-
tion's determination to maintain a good safety record. The
awards may include: AWWA's water drop pins, certificates,
and/or plaques shewing number of years without an acci-
dent. Consider publishing a utility newsletter on safety tips
or giving deta.is concerning accidents that may be helpful to
other operators in the organization. Awards may be given to
the organization in recognition of its effort in preventing
accidents or for its overall safety program. A suggestion
program concerning safety will promote and reinforce the
program and give recognition to the best suggestions. The
goal of all these efforts is to reinforce concerns for the safety
of all operators. If safety, as an idea, is present, then
accidents can be prevented.

Education of the operator in the use of tools and equip-
ment IS necessary. As pointed out abo^'o, OJT is not the
answer to a good safety record. A good safety record will be
achieved only with good work habits and safe equipment. If
the operator is trained in the proper use of equipment (hand
tools or vehicles), the operator is less likely to misuse them.
However, if the supervisor finds an operator misusing tools
or equipment, then it is the supervisor's responsibility to
reprimand the operator as a means of reinforcing utility
policies. The careless operator who misuses equipment is a
hazard to other operators. Careless operators will also be
the cause of a poor safety record in the operator's division
or department.

An important part of every job should be the consideration
of Its safety aspects by the supervisor. The superyisor
should instruct the foreman or operators about any dangers
involved in job assignmen.s. If a job is particularly danger-
ous, then the supervisor must bring that fact to everyone's
attention and clarify utility policy in regard to unsafe acts and
conditions.

1 Write or call your local safety council or National Safety Council, 444 N. Michigan Avenue, Chicago, Illinois 60611, phone toll free "hot
line" (800) 621-8051 (not applicable within Illinois).

ER?C 413

Safety 399

If the operator is unsure of how to perform a job, then it is
the operator's responsibility to ask for the training needeo.
Each operator must think, act. and promote safety if the
organization is to achieve a good safety record Training is
the key to achieving this objective and training is everyone s
responsibility — management, the supe visors, foremen
and operators

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 438.

20.01 What IS the mainstay of a safety program'?

20. OJ Why should you report even a minor injury?

20. OK Why should a safety officer review an accident report
form'?

20 OL A new inexperienced operator must receive instruc-
tion on what aspects of treatment plant safety'?

20.0M What should an operator do if unsure of how to
perform a job?

20.08 Measuring

To be complete, a safety program must also include some
means of identifying, measuring and analyzing the effects of
the program. The systematic classification of accidents,
injuries, and lost time is the responsibility of the safety
officer This person should use an analytical method which
would refer to types and classes of accidents. Reports
should be prepared using statistics showing lost time, costs,
type of injuries and other data based on a specific time
interval. Such data calls attention to the effectiverass of the
program and promotes awareness of the types o\ accidents
that are happening. Management can use this information to
decide where the emphasis should be placed to avoid
accidents. However, statistical data are of little value if a
report is prepared and then set on the bookshelf or placed in
a supervisor s desk drawer. The data must be distributed
and read by all operating and maintenance personnel

As an example. Injuries can be classified as fractures,
burns, bites, eye injuries, cuts and bruises. Causes can be
referred to as heat, machinery, falling, handling, chemicals,
unsafe acts, and miscellaneous. Cost can be considered as
lost time, lost dollars, lost production, contaminated water or
any other means of showing the effects of the accidents.

Good analytical reporting will provide a great deal of detail
without a lot of paper to read and comprehend. Keep the
method of reporting simple and easy to understand by all
operators, so they can identify with the causes and be aware
of how to prevent the accident happening to themselves
and/or other operators. Table 20.2 gives one method of
showing injury and cause in terms of operator-days lost.

ERIC

TABLE 20.2 SUMMARY OF TYPES AND CAUSES OF
INJURIES

Type of Injury

CAUSE OF INJURY

Unsafe Act

Chemical

Fails

Handling Objects

Heat

Machinery

Falling Objects

Stepping

Striking

Miscellanecus

TOTAL

Lacerations

Sprains

Eye Injuries

Bites

Cuts

Bruises

ContuMons

Miscellaneous

There are many other methods of analyzing data. Table
20 2 could be rearranged by using cost in dollars rather than
operator-days lost. Not all accidents mean time lost, but
there can be other cost factors. The data analysis should
also indicate if the accidents involve vehicles, company
personnel, the public, company equipment, loss of chemical,
or other factors. Results also should show direct cost and
indirect cost to the agency, operator and the public.

Once the statistical data have been compiled, someone
must be responsible for reviewing it in order to take preven-
tive actions. Frequently such responsibility rests with the
safety committee. In fact, safety committees may operate at
several levels, for example management committee, work-
ing committee, or an accident review board. In any event, the
committee must be active, be serious and be reinforced by
management.

Another means of measuring safety is by calculating the
injury frequency rate for an indication of the effectiveness of
your safety program. Multiply the number of disabling injur-
ies by one million and divide by th3 total number of employ-
ee-hours worked. The number of injuries per year is multi-
plied by one million in order to obtain injury frequency rate
values or numbers which are easy to use. In our example
problems we obtained numbers between one and one
thousand.

Injury Frequency (Numbe. of Disabling injuries/year) (1 ,000,000)
Rate Number of Hours worked/year

These calculations indicate a frequency rate per year,
which IS the usual means of showing such data. Not that this
calculation accounts only for disabling injuries. You may
wish to show all injunes, but the calculations are much the
same.

EXAMPLE 1

A rural water company employs 36 operators who work in
many small towns throughout a three-state area. The opera-
tors suffered four injunes in one year while working 74,880
hours. Calculate the injury frequency rate.

420

400 Water Treatment

Unknown

Injury Frequency Rate

Known

Number of Operators = 36
Number of Injuries = 4/yr

Number of Hours Worked = 74,880 yr
Calculate the injury frequency rate.

Injury Frequency _ (Number of Dtsablmg Injurres/year) (1 ,000.000)

Rate

Number of Hours Worked/year
(4/yr) (1.000.000)

74.880/yr

^ 53 4

EXAMPLE 2

Of the four injuries suffered by the operators in Example 1 ,
one was a disabling injury. Calculate the injury frequency
rate for the disabling injuries.

Known Unknown

Injury Frequency
Rate

Number of Disabling Injuries = 1 yr
Number of Hours Worked = 74,880 yr
Calculate the injury frequency rate.
Injury Frequency Rate _ ber of Disabling Injurres/yr) (1 .000,000)

(Disabling injuries)

Number of Hours Worked/yr
(1/yr) (1.000.000)
" 74.b30/yr

= 13 4

Yet another consideration may be lost-time accidents. The
safety officer's analysis may take into account many other
considerations, but in any event, the method given here will
provide a means of recording and measuring injuries In the
treatment plant. In measuring lost-time Injuries, a severity
rate can be considered.

A seventy rate is based on one lost ho'jr for every million
operator-hours worked. The rate is found by multiplying the
number of hours lost by one million and dividing by the total
number of operator-hours worked.

Injury Seventy Rate

EXAMPLE 3

(Number of Hours Lost/yr) ("i ,000.000)
Number of Hours Worked/yr

The water company described in Examples 1 and 2
experienced 40 operator-hours lost due to injuries while the

ERIC

operators worked 74,880 hours. Calculate the injury severity
rate

Known

Number of Hours Lost
Number of Hours Worked

40 hrs/yr
74,880 hrs/yr

Unknown

Injury Severity
Rate

Calculate the injury sev .ity rate.

(Number of Hours Lost/yr) (1,000,000)

Injury Severity Rate =

Number of Hours Worked/yr
(40 hrs/yr) (1,000,000)
74,880 hrs/yr

= 534

Notice that all these data points are based on a one year
time interval which makes them suitable for use by the safety
officer in preparing an annual report

20.09 Human Factors

First, you may ask, what is a human factor? Well, it is not
too often that a safety text considers human factors as part
of the safety program. However, if these factors are under-
stood and emphasis is given to their practical application,
then many accidents can be prevented. Human Factors
Engineering is the specialized study of technology relating to
the design of operator-machine interface. That is to say, it
examines ways in which machinery might be designed or
altered to make it easier to u-. , safer, and more efficient for
the operator. We hear a lot about making computers more
user friendly, but human factor engineering is just as impor-
tant to everyday operation of other machinery in the every-
day plant

Many accidents occur because the operator forgets the
human factors. The ultimate responsibility for accidents due
to human factors belongs to the management group. How-
ever, this does not relieve the operator of the responsibility
to point out the human factors as they relate to safety. After
all, It IS the operator using the equipment who can best tell if
It meets all the needs for an inter-relationship between
operator and machine.

The first step in the preve.ition of accidents takes place in
the plant design. Even with excellent designs, accidents can
and do happen. However, every step possible must be taken
during design to assure a maximum effort of providing a
safe plant environment. Most often the operator has little to
do with design, and therefore needs to understand human
factors engineering so as to be able to evaluate these
factors as the plant is being operated. As newer plants
become automated, this type of understanding may even be
more important.

Safety 401

Other contributing human factors are the operator's men-
tal and physical characteristics. The operator's decision-
making abilities and general behavior (response time, sense
of alarm, and perception of problems and danger) are all
important factors. Ideally, tools and machines should func-
tion as intuitive extensions of the operator's natural senses
and actions. Any factors disrupting this flow of action can
cause an accident. Therefore, be on the lookout for such
factors. When you find a system that cannot be acted upon
by inspection, change it. You may prevent an accident. If the
everyday behavior of an operator is inappropriate mth
regard to a specific job, reconsider the assignment to
prevent an accident.

The human factor in safety is the responsibility of design
engineers, supervisors and operators. However, the opera-
tor who IS doing the work will have a greater understanding
of the operator-machine interface. For this reason, the
operUor is the appropriate person to evaluate the means of
reducing the human factor's contnbution to the cause of
accidents, thereby improving the plant's safety record.

QUESTIONS

Write your answers in a notebook and then compare your
answers wi^li those on page 438.

20. ON Statistical accident reports should contain what
types of accident data?

20.00 How can injuries be classified*^

20. OP How can causes of injuries be classified*^

20. OQ How can costs of accidents be classified?

DISCUSSION AND REVIEW QUESTIONS

Chapter 20. SAFETY

(Lesson 1 of 4 Lessons)

1. Why must waterworks utilities have a safety program*^

2. How can a good safety record be accomplished*?

3. What IS the intent of the OSHA regulations'?

4. Why should water utilities establish a reporting system
that supplies data for a permanent record*?

5 Why do operators have the most to gam from an
effective safety program?

6. Who should review accident report forms'?

7. What topics should be included in a safety officer's talk
to new operators'?

8. What are the purposes of "tailgate" talks?

402 Water Treatment

Chapter 20. SAFETY

(Lesson 2 of 4 Lessons)

20.1 CHEMICAL HANDLING

20.10 Safe Handling of Chemicals

The water treatment plant operator handles a wide vanety
of chemicals depending on the type of plant. In a simple well
system, chlonne may be the only chemical used. In more
complicated plants, there may be chlorine, other gases,
sulfuric acid, lime, alum, powdered activated ca'^bon and
anhydrous ammonia. All of these chemicals fall into groups:
acids, hydroxides, gases, salts, organics and solvents. Each
group requires you, the operator, to have a good under-
standing of all types of chemicals. You must know how to
handle the many problems associated with each of these
elements or compounds. For example, you must know how
to store chemicals, understand the fire problem, the tenden-
cy to "arch"2 jn a storage bin, how to feed dry, how to feed
liquid, and how to make up solutions. All of these factors and
many more problems may cause an unsafe condition. Over-
heating gas containers, dust problems with powdered car-
bon, burns caused by a'^id, reactivity of each chemical under
a variety of conditions that may cause fire and explosion are
other safety hazards. You will need to know the usable limits
because of toxicity, the protective equipmerit required for
each chemical, each chemical's antidote, and how to control
fires caused by each chemical. Although you may not
regularly handle all of the chemicals listed here, you may
come into contact with them from tiine to time. Try at least to
learn all of the charactenstics or the chemicals you will use
regularly. For example, learn the boiling point, explosive
limits, reactivity, flammability,, first aid used for each chemi-
cal, and other characteristics that may prove helpful in
preventing a safety hazard. Study the chemistry of each
chemical used in the plant in order to have a safe plant in
which to work. In the following discussions we shall concen-
trate on the characteristics of each compound and point out
its hazards, reactivity and the information needed to avoid
conditions that may cause a safety problem.

20.11 Acids

Acids are used extensively in water treatment. For exam-
ple, hydrofluoric acid in fluoride addition or hydrochloric acid
in cleaning Table 20 3 lists many of the acids used in water

TABLE 20.3 ACIDS USED IN WATER TREATMENT

Name, Formula

Common Name

Available Specific
Forms Gravity

Flam-
mability

Color

Odor

Containers

Acetic Acid, CH3COOH

Ethanoic Acid

Solution

1.05

N/A

Clear

Sharp, pungent

Carboys, drums

Hydrofluosilicic. H2SiFg

Fluosilicic Acid

Solution

1.4634

N/A

Clear

Pungent fumes

Drums, trucks
R.R. tank cars

Hydrogen Fluoride, HF

Hydrofluonc Acid Liquid

0.987

N/A

Clear

Funies, toxic

Drums, tank cars

Hydrochloric Acid, HOI

Monatic Acid

Solution

1.16

N/A

Clear to
Yellow

Pu igent,
sj.focating

Drums, carboys

Nitnc Acid, HNO3

Liquid

1.5027

N/A

Colorless, Toxic fumes in
yellowish presence of light

Drums, carboys,
bottles

Sulfuric Acid, HgSO^

Oil of Vitriol;
Vitnol

Solution

(60-66^ G6) N/A
1.841

Clear

Odorless

Bottles, carboys,
drums, truck.

tank cars

2 Arch, To form a bridge or arch of hardened or caked chemical which will prevent the flow of the chemical

treatment and gives their charactenstics. This quick refer-
ence gives you a guide for learning some of each acid's
limitations and its reactivity with other compounds.

The antidote to all acids is neutralization. However, one
must be careful in how this is peformed. Most often large
amounts of water will serve the purpose, but if the acid is
ingesteo (swallowed), then lime water or milk of magnesia
may be needed. If vapors are inhaled, first aid usually
consists of providing fresh air, artificially restoring breathing
(CPR), or supplying oxygen. In general, acids are neutralized
by a base or alkaline substance. Baking soda is often used
to neutralize acids on skin because it is not harmful on
contact with your skin. To understand these reactions, you
\N\\\ need to know some acid-base chemistry. The knowledge
of acid-base chemistry and fast reactions on your part may
reduce the safety hazards involved in handling acids in water
treatment.

20. 1 10 Acetic Acid (Glacial)

This chemical is stable when stored and handled properly.
However, it may react volently with certain compounds such
as ammonium nitrate, potassium hydroxide and other alka-
line materials. Strong oxidizing glacial acetic acid is a
combustible matenal. Fires involving the acid may be extin-
guished wi.h water, dry chemical or carbon dioxide. Under
such conditions as adding water, the diluted acid may
produce hydrogen gas when it comes in contact with metals.
When the chemical is involved in a fire situation, self-
contained breathing apparatus must be used to protect the

Safety 403

operator against suffocation and problems caused by corro-
sive vapors

Most people ,'ind inhalation of acetic acid vapors in
concentrations over 50 ppm intolerable, resulting in nose
and throat irritations. Repeated exposure to high concentra-
tions may produce congestion of the larynx. Skin contact
with concentrated acetic acid can produce deep burns, with
skin destruction. High vapor concentration may blacken the
skin and produce allergenic reactions and eye irritation.
Possible permanent damage or immediate burns are caused
to the eye if the acid comes Into contact with the eye. If the
acid is ingested, severe intestinal Irntation will result as well
as burns to the mouth and upper respiratory tract.

Operators should be protected by adequate exhaust facili-
ties to ensure ventilation when working with acetic acid. At a
minimum, exhaust hoods should have air velocity of 100 fpm
(30 m/min). Wear rubber gloves and an apron to prevent skin
contact. Wear splash-proof goggles or a face shield to
prevent any eye contact. Gas-tight goggles may also be
needed to prevent vapors from irritating your eyes. An eye
wash station must be readily available where this chemical is
being handled. Also, respiratory equipment should be avail-
able for emergency use Acetic acid can be handled safely
by using adequate ventilation and safety equipment to
prevent skin and eye contact. Remember also that acetic
acid vapors can cause OLFACTORY FATIGUE (o\-fAK-\ore-
ee). This is a condition in which a person's nose, after
exposure to certain odors, is no longer able to detect the
odor. Acetic acid is detectable by your nose at 1 ppm, but
documentation has shown operators tolerating up to 200
ppm.

If a leak or spill should occur, notify safety personnel and
provide adequate ventilation. When cleaning up large spills,
wear self-contained breathing apparatus and equipment to
prevent contact with eyes and skin. To clean up spill areas
and remove chemical residue, cover the area with sodium
bicarbonate and flush away with an excess of water.

First aid for a etic acid exposure calls for removal of the
victim to fresh air, rinsing the mouth and nasal passages
with water and checking for Inhalation problems. If the acid
made contact with the eyes, immediately irrigate with water
for at least 15 minutes. Obtain medical attention. For skin
contact problems, wash with water immediately, if the acid
was swallovv'ed, 9»ve three gla^.ses of milk or water and
obtain medical altention quickly Acetic acid exposure, like
all other acids, must be treate immediately to prevent
damaoe to the victim.

20,111 Hydrotiuosilicic Acid

This chemical is hazardous to handle under any condi-
tions. Be extren-ely careful using this acid. The acid is
colorless, transparent, fuming, corrosive and is a li ,uid. A
pungent odor is created by the acid and contact causes skin
irritation. When the acid vaporizes, it decomposes into
hydrofluoric acid and silicon tetrafluonde. Hydrofluoric acid
can attack jlass. When handling the acid, always use
complete protective equipment, rubber gloves, goggles or
face shield, rubber apron, rubber boots and have lime slurry
barrels, epsom salt solution and safety showers (Figure
20.3) available. Always provide adequate ventilation be-
cause Its vapor can cause irntation to the respiratory sys-
tem. Careful maintenance of protective equipment is essen-
tial because the fumes of t acid corrode or etch glass on
the protective equipment.

First aid for eye contact is to thoroughly flush with water
for 15 minutes and get medical aid as soon as possible. For
skin contact, wash the affected areas witn water For gross
(large) contact, remove contaminated clothing under a safety
shower and thoroughly wash entire body for 15 minutes or
longer. In case of inhalation, remove operator to fresh air,
restore breathing, if required, and get medical aid.

20.112 Hydrofluoric Acid

This acid :S extremely poisonous, and produces terrible
sores when allowed to come into contact with the skin. The
t "id IS a clear, corrosive liquid that has a pungent odor. All of
the precautions discussed for hydrofluosilicic acid apply to
this acid also.

20. 1 13 Hydrochloric Acid

This ac'd IS used most often for cleaning in and around the
treatment plant and is known as munatic acid. The acid is
also used very frequently in the laboratory. Hydrochloric
acid is stable vA^en properly contained and handled. This
acid IS one of tne strong mineral acids and therefore, is
highly reactive ^*i;h metals and these oxides: hydrocarbon,
amine, and carbonate compounds. The acid liberates signifi-
cant iGveis of hydrogen chloride gas (HCI) beuduse of Its
vapor pressure at room temperature a"d gives off large
amounts of gas when heated. In reactions with most metals,
hydrochloric acid will produce hydrogen gas.

Inhalation of HCI vapors or mists for long periods can
cause damage to teeth an*^ irritation to ine nasal passages.
Concentrations 750 ppm or more will cause coughing,
choking and produce severe damage of the mucous mem-
branes of the respiratory tract. In concentrations of 1300
ppm, HCI IS dangerous to life. Ingoction can cause burns of
the mouth and digpstive fact.

When handling HCI. provide adequate exhaust facilities to
ensure ventilation arj wear protective clothing and equip-
ment to prevent body contact with the acid. Use rubber
gloves, rubber apron, rubber boots and wear a long-sleeved
shirt when handling nydrochloric acid To protect your eyes
against splashing of :^e acid, you must .vear safety goggles
and/or a face shield, ^here should ai.' iys be an eye wash
station and safety sho.ver located near -^reas where th-f^ acid
IS to be used.

First aid consists of thoroughly fiLsr-. ng the *»yes with
running water for 15 min jtes and se^Jr g medical aid. If
hydrochloric acid comes m contact •'ith skin, wash the
affected areas with water ^or gross co i*act remove cloth-
ing under the safety show-;' and contint' showering for 15
minutes or longer. Shoula 'he acid be ingested, give ime

404 Water Treatment

Model 01-0354-07— Face Wash. Yello-Bowr^
and Stainless Steel pipe and valve.

Specially Coated Corrosion-Proof Models

In addition to corrosion-resistant Stainless Steel,
various coatings are available for protection
against corrosive atmospheres at additional cost.
The sprayed and baked epoxies as well as the
new fluorocarbon coatings can be applied on all
galvanized and stainless pipe and fittings. Specify
type of coating required.

Plastic Models Available

All PVC plastic models for Face/Eye Washes
as well as combination Shower-Face/Eye Wash
assemblies. Ask your distributor for details.

Part * 01-1128-06—

Shower and wash sign.
Rugged plastic base,
yellow and black con-
trast, 8" x 18".

Model 01-0502-19— Shower/Face Wash. Yello-
Bowr". Stainless Steel piping, fittings, and valves.

Fig. 20.3 Safety shower with face-eye wash

(Permission of Nevada Safety A Supply)

water, or water and milk of magnesia. Do not induce
vomiting; get medical aid. In case of inhalation, remove the
victim to fresh air, restore breathing if required, and get
medical aid.

Store acid containers closed in a clean, cool, open and
well-ventilated area. Keep out of the sun. Keep the acid
away from oxidizing agents or alkaline materials. Provide
emergency neutralization materials in use areas.

20.114 Nitric Acid

Like hydrochloric acid, nitric acid is one of the most
commonly used acids in the water treatment laboratory and
plant. The acid is a powerful oxidizing agent and attacks
most metals. Nitric acid is stable when properly handled and
placed into a proper container. The acid is one of the strong
mineral acids, and is highly reactive with materials such as
metals. When handling nitnc acid, use protective clothing
and equipment to prevent body contact with the liquid. Such
equipment includes rubber gloves, rubber apron, and safety
goggles or a face shield for eye protection against splashing
of the acid. Nitric aad is a strong, poisonous and highly
corrosive liquid and must be handled care illy. The acid
forms toxic fumes in the presence of Lght; therefore, it
should be kept out of the sun.

Like other acids, nitric acid should be stored in clean, cool,
well-ventilated areas. The areas should have an acid-resist-
ant floor and adequate drainage. Keep it away from oxidiz-
ing agents and alkaline materials. Protect containers from
damage or breakage. Avoid contact with skin and provide
emergency neutralization materials ,.nd safety equipment in
use areas.

First aid for skin contact is to flush thoroughly with water
for 15 minutes. Get medical aid if needed. This acid will
cause burns, but these can be greatly reduced if the contact
area is immediately flushed. For gross (large) contact, re-
move contaminated clothing under a safety shower. For eye
contact, flush with water for 15 minutes and get medical aid.
If acid IS ingested, give lime water or water with milk of
magnesia; get medical aid. For inhalation, remove to fresh
air, restore breathing if required, and get medical aid.

20.115 Sulfuric Acid

Thts mineral acid is highly corrosive and will attack most
metals. Sulfuric acid is also very reactive to the skin and
must be handled with extreme care or you will suffer severe
burns. Even when the acid is diluted, it is highly corrosive
and must be contained in rubber,, glass or plastic-lined
equipment. The acid will decompose clothing and shoes.
Sulfuric acid should not come in contact with potassium
permanganate or similar compounds. Sulfuric acid reacts
violently with water. ALWAYS POUR ACID INTO WATER
while stirnng to prevent the generation of steam and hot
water which could boil over the container and cause serious
acid burns.

As with other mineral acids, this material is stable when
properly contained and handled. When you are handling
sulfuric acid, you must use protective clothing and equip-
ment to prevent body contact with the acid. Wear rubber
gloves, safety goggles and/or a face shield for eye protec-
tion against splashing. Also wear a rubber apron, rubber
boots, and long-sleeved shirt. The eye wash station and
safety shower must be located nearby where the acid is
being handled. The area should be well-ventilated, the acid
should be stored in closed containers in a clean, cool, open
area. The area should have an acid-resistant floor which is
well drained. Keep away from oxidizing agents and alkaline

ERIC

Safety 405

materials and protect the containers from damagt or break-
age

Because the acid is highly corrosive and causes severe
burns, first aid for sulfuric acid must be immediate to avoid
substantial damage to human tissue. For eye contact, flush
thoroughly with running water for 15 minutes, get medical
aid — the first seconds are important. For skin contact,
wash affected areas thoroughly with water. For gross (large)
contact, remove contaminateo clothing under the safety
shower with prolonged washing for at least 15 minutes. In
cases of ingestion, give lime water or water and milk of
magnesia to drink; get medical aid. When working with
sulfuric acid, avoid skin contact and ai vays provide emer-
gency neutralization materials and a safety shower near the
work areas.

QUESTIONS

Wnte your answers in a notebook and then compare your
answers with those on page 438.

20.10A What does an operator need to know about chemi-
cals used in a water treatment plant?

20.11 A What should be done if an operator inhales acid

vapors'?

20.1 IB Acetic acid will react violently with which com-
pounds'?

20 1 1C Under what conditions can acetic acid be handled
safely'?

20 11D What protective equipment is necessary for han-
dling hydrofluosihcic acid'?

20.1 1 E How can the inhalation of hydrochloric (HCI) vapors
or mists cause damage to opei<:*ors?

20 11F How should nitric acid be stored?

20.12 Bases

The bases that are used in water treatment are known as
hydroxides From a functional standpoint they are used to
raise pH. Most common bases are compounds of sodium,
calcium and ammonium which are strong bases. However,
there are other weak bases, such as silicate, carbonate and
hypochlorite. But fiom the p'jint of safety, both weak and
strong bases must be given the same consideration when
being handled Some are very toxic, and will attack human
tissue very rapidly and cause burns. Explosive reactions will
occur when bases come in contact with an acid and hazard-
ous decomposition products are created under certain con-
ditions. Bases must be neutralized with dilute acids. Howev-
er, the operator must work carefully because under some
conditions there may be other reactions, suuh as with
hypochlorite compounds. Therefore, you should understand
acid-base chemistry before handling any of the basic com-

406 Wat**r Treatment

pounds used in water treatment Table 20.4 give? some of
the common basic compounds used in water treatment. The
following sections will discuss some of their characteristics
and the precautions the operator must use to safely handle
such compounds.

12.120 Ammonia

The operator may use one of two forms of ammonia,
anhydrous or hydroxide. The first (anhydrous) is in a gas
form and requires one type of consideration. The hydroxide
IS a liquid and requires another type of consideration.
Anhydrous ammonia in the gaseous state is colorless, about
0.6 times as heavy as air. In a liquid state, ammcnia is also
colorless, 0.68 times as hsavy as water and u vaporizes
rapidly. The ammonia gas is capable of forming explosive
mixtures with air. For your own safety, be aware of the
possibility of suffocation since the gas can displace air
which contains oxygen. Although the vapors are not poison-
ous, they can and will irritate the mucous membranes of the
eyes, nose, throat and lungs. Irritation will be detected in
concentrations of 5.0 ppm and when human tissue comes in
contact with the liquid, it will cause severe burns.

When handling ammonia or working in an ammonia p ivi-
ronment, respiratory protection is a requirement. For entry
into emergency areas, use only a self-contained breathing
apparatus. Install a good ventilation system to control va-
pors In the application room. Use protective clothing, rubber
gloves, apron, boots and face and eye protection if you are
going to work with ammonia for long penods.

Care must be used when storing or transporting contain-
ers Always keep cylinders with caps in place when not in
use. Store cylinders in a cool, dry location away from heat
and protect from direct sunlight. Storage near radiators,
steam pipes or other sources of neat may raise the pressure
to a dangerous point, whereas dampness nay cause exces-
sive corrosion. Do not store in the same ''oom with chlorine.
Always use lifting clamps or cradles. Avoid hoisting the
cylinde z using ropes, cables or slings and never drop the
containers Control ammonia Isaks. They can be detected by
cdor or by using a cloth swab soaked with hydrochloric acid.
This will form a white cloud of r-mmonium chloride.

Ammonia gas will burn if it is blended with z\r in a mixture
containing 15 to 28 percent ammonia by volume. Check
cylinder valve stems for leaks* tighten the packing gland nut
only with a special wrench pi /ided for such purposes. If a
serious leak m a cylinder cannot be controlled, place the
container in a vat of water. Fifty-three pounds of ammonia
will dissolve in 100 pounds of water at 68''F (20''C). NEVER

neutralize liquid ammonia with an acid. The reaction gener-
ates a lot of heat which may speed up the release of
ammonia gas.

First aid for skin contact with ammonia is to flush with
large amounts of water for 5 to 10 mmutes and get medical
aid Remove contaminated clothing under a safety shower.
For eye contact, flush thoroughly with water *or 15 minutes
immediately, and get medical aid. In the case of inhalation,
remove to fresh air and restore breathing. If required, get
medical aid. Nose and throat burns should be washed with
water and nnsed with two percent bone acid solution. Urge
the patient to drink large amounts of milk.

Ammonium hydroxide is an aqueous (watery) solution of
anhydrous ammonia and is quite volatile (will evaporate) at
atmospheric temperatures and pressures. This solution can
cause local skin irritations A strong solution will cause
human tissue destruction on contact with eyes, skin and
mucous membranes of the respiratory system, so avoid
contact with the compound. The solution will cause severe
burns depending upon solution icentrations and length of
contact time. The solution's vapor causes the same effects
as the gas First aid should be the same as for anhydrous
ammonia.

20. 121 Calcium Hydroxide

Hydrated lime (calcium hydroxide) is one form nf hme and
quicklime (calcium oxide) is another form. The hydrated lime
IS the least troublesome of thp two forms. The hydrated lime
IS less caustic and is therefore less irritating to the skin, but
can cause injury to eyes. However, as a dust, it is just as
hazardous as quicklime. Quicklime is a strong caustic and
irritating to personnel exposed to the compound. When
quicklime is mix^d with water, a great deal of heat is
generated which can cause explosions.

Name, Formula

TABLE 20.4 BASES USED IN WATER TREATMENT

Common
Name

Available
Fomis

Calcium Hydroxide and
Oxide, Ca(0H)2 or CaO

Hydrated Lime Dry Powder,
or Quick Lime Lump

Sodium Hydroxide, NaOH Caustic, Lye

Codium Silicate, NagSiOg

Water
Glass

Hypochlorite Compounds, HTH
NaOCI, Ca(0CI)2

Sodium Carbonate, NagCOg Soda Ash

Lump, Liquid,
Flake

Liquid

Powder

Spec. Grav.

50-70 lbs
per cu ft

1.524

1.35-1.42

23. 35, and
65 Ibs/cu ft

Flammabliity

Color

Odor

Containers

N/A

White

Dust

Bags. Bulk,
Trucks

May Cause
Flammable
Condition

Opaque
White

Toxic,
Pungent

Drums, Bulk,
Trucks

N/A

Opaque

N/A

Drums, Bulk,
Trucks

Explosive with
Antifreeze

White

Toxic CIg,
Pungent

Cans, Drums

N/A

White

Dust

Bags, Bulk,
Trucks

Safety 407

Both qucklime and hydrated lime should be stored in cool,
dry areas. Care must be taken to avoid mixtures of alum and
quicklime, since quicklime tends to absorb the water that
forms as alum crystallizes (water of crystallization) away
from the alum. In a closed container this could lead to a
violent explosion. Equal care should be taken to avoid
mixtures of fernc sulfate and lime.

When handling bc*h forms of lime, the operator should
use chemical goggles and a suitable dust mask to protect
the eyes and mucous membranes. Also wear proper cloth-
ing to protect the skin, because with long contact the lime
can cause dermatitis or burns, particularly at perspiration
points. Always shower after handling quicklime. All opera-
tors should wear a face shield when inspecting lime slakers.
Hot lime suspension that splatters on the operator may
cause severe burns of the eyes or skin. The hot mist coming
from the slakers is also dangerous. The loss of water supply
to a lime slaker can create explosive temperatures.

First aid for lime burns, which are like burns -rom other
caustics, consists of alternatively washing with water and a
mild acetic acid solution. One may also use large amounts of
soap and water. For eye contact, wash immediately with
large amounts of warm water and nnse with a boric acid
solution. Get medical aid. For irritation of nose and throat
because of exposure, see a physician.

20,122 Sodium Hydroxide (Caustic Soda)

Sodium hydroxide is available in pellet and flake forms.
Caustic soda usually comes as a 50 percent solution of
sodium hydroxide. This base is a strong caustic alkali and
very hazardous to the operator. This compound is extremely
reactive. Sodium hydroxide absorbs carbon dioxide from the
air, reacting violently or explosively with acid and a number
of organic compounds. Caustic soda 1) dissolves human
skin, 2) when mixed with water cajses heat, and 3) reacts
with amphotenc metals (such as aluminum) generating hy-
drogen gas which is flammable and may explode if ignited.
Sodium hydroxide can be dissolved in water and the solution
used for the adjustment of pH because it is a liquid and easy
to feed. This base is extensively used in water treatment.
Because of its everyday use, you may forget just how
he zardous this compound if and throug. ♦ neglect may injure
yourself or another operator. Only trairjed and protected
operators should undertake spill cleanup. The operator
must act cautiously, dilute the spill with water and neutralize
with a dilute acid, preferably acetic.

When handling caustic soda, control the mists with good
ventilation. Protect your nose and throat with an approved
respiratory system. For eye protection, you must wear
chemical worker's goggles and/or a full face shield to
protect your eyes. There must be an eye wash and safety
shower at or near the work station for this chemical. Protect
your body by being fully clothed, and by using impervious
gloves, boots, apron and face shield.

Special precautions to be taken when handling or storing
caustic soda include (1) prevent eye and skin contact, (2) do
not breath dusts or mists, and (3) avoid storing this chemical
next to strong acids. Dissolving sodium hydroxide in water
or other substances generates excessive heat, causes
splattering and mists. Solutions of sodium hydroxide are
viccous and slippery.

First aid for the eyes consists of irrigating the eyes
immediately and continuously with flowing water for at least
30 minutes. Prompt medical attention Is essential. For skin
burns, immediate and continuous, thorough washing in
flowing water for 30 minutes Is important to prevent damage

ERIC

to the skin Consult a physician if required. In case of
inhalation, remove victim to fresh air, call physician, or
transport injured person to a medical facility For ingestion,
give large amounts of water or milk and immediately trans-
port injured person to a medical facility, DO NOT INDUCE
VOMITING.

You may also have occasion to use sodium hydroxide as
flakes or pellets AH of the precautions stated for liquid
caustic also apply for the flake form

20,123 Sodium Silicate

This chemical is a liquid as used in water treatment.
However, it is non-toxic, non-flammable, and non-explosive,
but presents the same hazards to the eyes and skin as any
other base compounds. Sodium silicate is a strong alkali and
should be handled with care by using goggles or face shield,
wearing gloves and protective clothing. The chemical will
cause damage to the eyes and skin, but it is less dangerous
than other alkaline compounds used in water treatment.

First aid for the eyes is to flush immediately and thorough-
ly with flowing water for at least 15 minutes. Get medical
attention. If sodium silicate makes contact wit' zk\n, wash
thoroughly with water, particularly if the solution is hot. Then
wash the skin with a 10 percent solution of ammonium
chloride or 10 percent acetic acid. For ingest'on. give plenty
of water and dilute vinegar, lemon or orange juice. Follow
this with milk, white of eggs beaten with water or olive oil.
Call a physician.

2ii124 Hypochlorite

A number of hypochlorite compounds are commercially
available for use i' A'ater treatment. If you understand the
precautions for one such compound, you will know what
steps must be taken with other hypochlorite compounds,
su^h as calcium, sodium, or lithium. These '"hemicals may
be used in either a liquid or dry form. There are several
grades of hypochlorite compounds, but all are good oxi-
dizers and are used for disinfection. When these com-
pounds come into contact with organic materials, their
decomposition releases heat very rapidly and produces
oxygen and chlorine. Although hypochlorite compounds are
non-flammable, they may cause fires when they come in
contact with heat, acids, organic or other oxidizable sub-
stances.

All solutions of hypochlontG coinpounds attack the skin,
eyes or other body tissues with which they come into
contact. When handling hypochlorite, liquid or dry, use
suitable protective clothing such as rubber gloves, aprons,
goggles and/or a face shield. Be u.yare that many times
these compounds are stored in containers and give off
chlorine gas when opened. Store these compounds in a
cool, dry, dark area.

408 Water Treatment

First aid for eyes is to flush with plenty of water lOr at least
15 minutes and see a ohysiclan. If hypochlorite compounds
come in contact with tfie skin, flush thoroughly with water for
at least 15 minutes, and get medical attention as needed. In
case of ingestion, wash out mouth thoroughly with water
and give plenty of water to drink, and get medical attention.
For inhalation, move the victim into Uesh air and get meJical
attention.

Over-exposure to any of the hypochlorite compounds may
produce severe burns, so avoid contact with these com-
pounds. They are hazardous and can attack skin, eyes,
mucous membranes and clothing.

20, 125 Sodium Carbonate

Soda ash is a mild alkaline compound, but requires safety
precautions to minimize hazards when handling the chemi-
cal. An adequate ventilation system is needed to control the
dust generated by the compound. Wear protective gear,
such as chemical safety goggles and/or a face shield, a well-
fitting dust respirator and protective clothing to avoid skin
contact. You should protect yourself by using a suitable
cream or petroleum jelly on exposed skin surfaces, such as
neck and hands. This compound's dust irritates the mucous
membranes and prolonged exposure can cause sores in
your nasal pasi.age.

First aid for exposure tc eyes (dust or solution) requires
irrigation with water immediately for at least 15 minutes.
Consult a physician if the exposure hai; been severe. For
skin exposure, wash with large amounts of water; for
contaminated clothing, wash before reusing. For inhalation
or irritation of the respiratory tract, gargle or spray with
warm water, and consult a physician as needed.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 439.

20.1 2A What are the two forms of ammonia used by
operators

20.1 2B How should ammonia be stored?

20.1 2C What are the two forms of lime used in water
treatment plants'?

20.1 2D What would you do if someone swallowed sodium
hydroxide?

2012E What would you do if sodium silicate came in
contact with your skin?

20.13 Gases

There are a number of gases used in water treatment
(Table 20 5) Most are supplied in steel drum containers,
others must be generated on site. Some gases can be seen,
others call the operator's attention by odor, and still others
cannot be seen or detected by odor, yet are deadly. In this
section we shall only discuss those which are supplied in
containers that the operator must connect, disconnect,
handle or store.

Exposure to the liquid form of these gases usually will
cause damage to human tissue, such as skin burns, but the
most important factor to remember is the displacement of
oxygen. Most gases are heavier than aii aiici remove air
from a room by displacement. Therefore, it is very important
to have the right type of ventilation and respiratory protec-
tion. Use only the self-contained breathing apparatus when
working in emergency areas.

20.130 Chlorine (Cl^)

Safety is of the utmost importance when handling chlo-
rine. Do not treat chlorine cylinders roughly; never drop them
or permit collision of two or more cylinders. Never hoist
chlorine cylinders by the neck. Always use lifting clamps or
cradles — do not use ropes, cables or chains. Store the
cylinders in such a way that they cannot fail. Do not store
chlorine cylinders below ground level and always keep the
protective cap on the cylinder when it is not in use. Mark the
empty containers and store them aside from full cylinders.
Always store containers in an upright position in a clean, dry

TABLE 20.5 GASES USED IN WATER TREATMENT

Name, Formula

Ammonia,

Chlorine, CL

Carbon Dioxide,
CO2

Sulfur Dioxide,

SO,

er|c

Common Available Spe'tific
Name Forms Gravity

Flammablllty Color

Ammonia Liquid-Gas 0.04813 lbs/ None

cu ft @ 0°C

Liquid
Chlonne

Dry Ice

Liquid-Gas 1.46b (a>0°C None

Liquid-Gas 0.914

None

Sulfuric Acid Liquid-Gas 1.436 ^0°C None
Anhydride

42j

Colorless

Greenish
Yellow

Colorless

Odor

Crntainers

Irritating
Irntating

Odorless

Cylinders,
Tanks, Trucks

Cylinders,
One Ton Units,
Tank Cars

Bulk Liquid
Under Pressure

Suffocating, Cylinders,
Pungent One Ton Units,
Tank Cars

Safety 409

location free of flammable materials. The storage area must
be equipped with forced-exhaust ventilation with starting
switches located c n the outside of the storage room. Ventila-
tion must provide at least one complete air change per
mmute. The temperature of the storage room should never
be permitted to approach 140^F (60^C). Protect the chlonne
cylinder from heat sources and never use an open flame on
cylinders or pipes carrying chlorine. If chlorine is heated, the
increase in temperature will cause an expansion of the gas
which results in an increase in pressure inside of the
cylinders or piping, resulting in rupture of the containers.

When working with chlorine, be equipped to control chlo-
nne leaks which are most often found in the control valve.
Repair kits are available for the lOO- and 150-pound (45 and
68 kg) cylinders, as is emergency equipment for the one-ton
(909 kg) tanks for controll-ng leaks. Each operator must be
trained in the use of theso emergency kits and must practice
with the equipment at least cnce a year. Always check out
even the slightest odor of chlorine; it may indicate a leak.
Chlorine leaks only get worse. Small leaks can grow very
rapidly causing serious problems that could have been
easily solved as a small leak. There should always be two
operators attending a chlorine leak, one to do the repairs
and the other to act as safety observer. Some repairs
require two operators to do the job (depends on leak and
repair kit). Once again, use only the self-contained breathing
apparatus when repairing a chlorine leak.

When connecting chlorine cylinders, be very careful with
the threaded connections; never use two washers, use only
one. If It does not work weli, remove the washer and use
another one. Do not reuse an old or used washer; always
use a new washer. By taking this precaution, by cleaning the
threads and washer, and by being careful with the thread
setting, many chlonne leaks will be prevented. You MUST be
aware whethor you are using gas or liquid when connecting
the container. On the one-ton (909 kg) tank, the top valve is
for gas, the bottom valve is for liquid. If liquid chlorine is
allowed into a gas feed system it will cause "freezing"^ and
shut down (plug) the system. Similarly, if liquid gets into the
gas outlet, it will cause problems by "freezing." You must not
panic in this situation. Do not do anything as foolish as
adding heat by open flame or electrical heaters to clear a
"frozen" (plugged) gas line. Get help from someone expe-
rienced with chlonne cylinders.

Never make repairs to the valve or chlonne container. Just
stop the leak, perhaps by tightening the packing on the valve
stem or placing the safety device onto the cylinder. Let the
chlorine supplier repair the container. Never use a wranch
longer than six inches (15 cm) to open the cylinder valve,
making one complete turn of the valve stem in a counter-
clockwise direction. The one turn will open the valve suffi-
ciently for the f.aximum discharge. As a safety consider-
ation, cylinders are equipped with fusible metal plugs which
are designed to melt at 1 58 to 1 68*'F (70 to 76*^0). This will al-
low the cylinder contents to discharge and prevent rupturing
of the tank. On 1 00- to 1 50-pound (45 to 68 kg) cylinders, the
plug IS located just below the valve seat. The one-ton (909
kg) tanks have six such plugs; three on each end. Should
one of these plugs molt, permitting liquid chlorine to dis-
charge, place the cylinder in a position with the leak at the
top of the tank so that it permits the chlorine gas (rather than
the liquid) to discharge. This action will reduce the amount of
chlorine being discharged because the liquid will change to a
gas to escape. In doing so, it will lower the temperature of
the container, reducing the discharge rate.

3 Liquid chlorine becomes a solid around -103 to
line.

All employees, Maintenance personnel and operators who
handle chlorine must have access to an approved chlonne
gas mask (Figure 20.4) They must be instructed in the use
and maintenance of this equipment. A monthly program
should be conducted to familiarize and train each user of the
safety equipment. Those employees who are to use the
chlorine emergency equipment should practice with this
equipment every oix months while wearing a self-contained
breathing apparatus. The emergency kit consists of clamps,
gaskets, drift pins, hammers, wrenches, and other tools
needed for repairing leaks. The operator may not be able to
practice with all of the tools, but inspection and practice
gives the operator an opportunity to do maintenance on the
emergency equipment.

All operators working with chlonne should be familiar with
methods of detecting chlorine leaks. When testing for leaks,
use ammonia water on a small cloth or swab on a stick or
use an aspirator containing ammonia water. This will form a
white cloud of ammonia chlorine. Leaks should be repaired
immediately. Jo not apply the ammonia swab directly to the
equipment surface. Also do not spray ammonia into a room
full of chlorine because a white cloud will form and you won't
be able to see anything.

Many plants are equipped with chlonne gas detectors.
This equipment must be maintained weekly. If not properly
maintained, it may not be operable when you need it.
Change the electrolyte regularly, test the alarm and keep the
detectors clean and in good repair.

Someone must be assigned the responsibility for mainte-
nance of the self-breathing apparatus. That operator must
keep records of the maintenance problems and of monthly
drills using the gear. The a^oigned operator should check
the masks for leaks, loose eyepieces, faulty tubing, or other
worn or defective spots. If inspection indicates any defective
parts, they should be discarded or repaired by a properiy
trained employee. Remember, in high concentrations of
chlorine within a confined space where oxygen can be
displaced, DO NOT USE THE CANISTER TYPE OF MASK.
NO CANISTER CAN PROVIDE OXYGEN. Therefore, use
only self-contained breathing apparatus or a hose-type
mask supplied with air (Figure 20.5).

If you are caught in an area containing chlorine, do not
panic, but leave immediately. Do not breathe or cough, and
keep your ^ <?ad high until you are out of the affected area.

The first safety measure you can take when entenng a
chlonnation room is to make sure the ventilating system is
working. The ventilating system for the chlorination room
should be working all the time. Doors of chlorination rooms
should have panic bars as door openers so that in an
emergency you will not have to search for the door opener.
All safety equipment should be located outside of the
chlonnation room, but close enough so you can find the
equi,3ment when needed.

First aid for eyes exposed to liquid chlorine is immediate
irngation with flowing water for at least 30 minutes. Medical
attention is essential. If the eyes are exposed to chlorine
gas, immediately irrigate with flowing water for a period of
15 minutes. Get medical aid. If skin is exposed to liquid
chlorine, it will most likely cause burns. The skin should be
washed with flowing water for 30 minutes. If the skin is
burned, get medical attention. Chlorine gas can becom'
trapped in the clothing and react with body moisture to forn

- IOj'^C. The liquid can plug a chlorine gas line which operators refer to a "frozen"

43J

410 Water Treatment

scon PRESUR-PAK lla

SPECiFICATiONS
AIR SUPPLY

Rsud Duration at modsraU txtrtlon
(MESA/NIOSH t«ft
procedure) *

Cylinder C«P«city at 2216 ptf

US£ FACTORS

Weight, at worn, fully chargad

(appro x»)
Donnino Spaad (tralnad pmtonn^l)

Facepiaca (Scottoramlc w/nota cup)
Cylinder and Valva connection
Cyllndar Changa

Harn««f Wabbing (raplacaabia without

tools or rivatf)
Transport arKi Storaga

SHIPPING WEIGHT

NOTES: POStTlVt PRESSURE

BACK'PAK STYLE

30 min.

45c»u ft.

32 Ibt.
undar 30MCf.

Widavlflon, antl-fogging
Straight thraad, gatkat taal
Haitd ditconnact, no tools raq'd

Polypropylana

Custom Molded High Dantlty
Polyathylena Case

48 lbs.

Fig, 20.4 Chlorine gas ma$K

(Permission of Nevada Safety & Supply)

hydrochloric acid which coJd burn the skin. Remove the
clothing of the victim and wash the body down with water. In
case of inhalation, remove the victim to fresh air, administer
oxygen if available, call a physician or transport the injured
person to a medica' facility. Ingestion is not a problem
because chlorine is a gas at room temperature.

Each operator should have a copy of the Chlorine Insti-
tute's CHLORINE MANUAL^ You should read this manual
and review it at least once every year. The manual gives data
concerning chlorine as an element and gives you sugges-
tions for safely handling this hazardous liquid or ges.

20,131 Carbon Dioxide (CO^)

Water plant operators are not often exposed to carbon
dioxide because of its limited use, but it is hazardous and
can cause suffocation due to the lack of oxygen. Therefore,
when using COg keep in mind the carbon dioxidp safety
considerations The problem with carbon dioxide is that it is
odorless, colorless, and will accumulate at the lowest possi-
ble level because it is heavier than air.

Carbon dioxide is obtained in bulk lots, as a liquid under
pressure. This gas must be vaporized before using. COg is
also prepared by generation on site In either case, good
ventilation will reduce the hazards of using 00^, This will

co»"*'ol the accumulating effects of the gas. If you must go
into a COg-filled room, use a self-contained breathing appa-
ratus, not a canister gas mask. Carbon dioxide displaces
oxygen and you may suffocate with the canister type of
mask. Exposure to carbon dicxide does not require any
protection of the eyes, skin or other parts of the body, but
take precautions when entering rooms, low spots, or man-
holes that may be filled with carbon dioxide.

First aid involves moving the victim to fresh air, giving
resuscitation if the victim has stopped breathing, and getting
medical attention.

* CHLORINE MANUAL (4th Ec* Jon), The Chlorine Institute, Inc., 2001 L Strec*t, SW, Washington, DC 20036. Price, $10.00

er|c

431

Safety 411

Dual m'tr supply cylinder being uMd with 900007 Mrias
hosclina Atr-Pak with Egress.

Typical fixed air supply installation usiri^ **igh pressure air cylinders.
Fig. 20.5 Hose-type mask supplied with air

(Permission of Nevada Safety & Supply)

412 Water Treatment

20.132 Sulfur Dioxide (SO2)

This gas Is about 2.3 times as heavy as air and therefore
will accumulate in low areas. Sulfur dioxide is colorless in
the gaseous form. As a liquid it is also colorless and, when
unconfined. will vaporize rapidly into a gas. The gas is
extremely irritating and, like chlorine, will react readily with
the respiratory system if inhaled. Sulfur dioxide causes
varying degrees of Irritation to the mucous membranes —
eyes. nose, throat and lungs. The damage is caused by the
formation of sulfurous acid in reaction with moisture in these
location^. Sulfur dioxide can be readily detected in concen-
trations of 3 to 5 ppm. In higher concentrations, it is unlikely
that you will remain in the area unless you are unconscious
or trapped. If the liquid comes into contact with the skin, it
may cause local freezing as the liquid evaporates.

Always use self-contained breathip'^ apparatus around
sulfur dioxide and never use the canister type. As with other
gases, good ventilation is essential in a roonri where sulfur
dioxide is being used. The fans should be used to dissipate
any gas vapors that may occur. There should always be an
eye wash fountain close to the work area where sulfur
dioxide is used.

First aid for eyes exposed to or splashed with sulfur
dioxide Is washing immediately with water for at least 15
minutes, then getting medical attention. In case of inhalation,
remove victim to fresh air, give resuscitation if needed,
consult a physician or transport the injured person to a
medical facility. Sulfur dioxide leaks and injuries should be
treated similar to chlorine problems.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 439.

20.1 3A Where are chlorine leaks most often found?

20.1 3B What is the purpose of the fusible metal plugs on
chlonne cylinders?

20.1 3C How can chlorine leaks be detected?

20.13D What safety considerations must be observed
when using carbon dioxide?

20.14 Salts

There are many salts (chemicals) used in water treatment.
Table 20.6 lists the salts that will be discussed in this
section. If you would like additional information about com-
pounds not listed, request a data sheet about specific
compounds from the suppliers of the chemicals. Review the
chemistry of the compounds in Table 20.6 and become
familiar with each chemical's characteristics. You should
become well trained in how to handle each chemical and
know and observe the appropriate safety precautions. For
most of these salts, ventilation, respiratory protection and
eye protection will prove adequate. Other problems may
involved chemical solutions and dust. The solution may
attack skin and clothing. The dust may attack the respiratory
system or cause an explosion. Even though these chemicals
do not normally react violently, use the following procedures
when handling such salts to reduce the hazards and to
provide a safe working location.

TABLE 20,6 SALTS USED IN WATER TREATMENT

Available

Density,

Name, Formula

Common Name

Forms

Lbs/Cu Ft Flammability

Aluminum Sulfate,
AySO^ja'UHgO

Alum. Filter Alum

Liquids,
Powder, Lump

1.69 (S.G.)
38-67

None

Ferric Chloride.
FeCl3

Ferrichlor,
Chloride of Iron

Syrup, Liquid,
Lump

60-90

None

Fetnc Sulfate.
Fe2(SO,)3

Ferrifloc. Ferrisul

Powder,
Granule

70-72

None

Ferrous Sulfate.

Coppras, Green
Vitriol

Crystal,
Granule, Lump

63-66

None

Sodium Aluminate,
NBgOAIgOj

Soda Alum

Dry Crystal,
Liquid

(27° B6)

None

Fluoride Compounds,

NaF

HjSIFe.

Liquid and
Powder

50-75

None

Sodium Hexameta-
phosphate, (NaP03)g

Calgon, Glassy
Phosphate

Crystal,
Flake

None

Copper Sulfate,
CuSO^

Blue Vitriol,
Blue Stone

Crystal,
Lump, Powder

60-90

None

Sodium Chlorite,
NaOCI

Technical
Sodium Chlorite

Powder, Flake,
Liquid

70 dry

Oxidizer

Potassium

Permanganate,

KMnO^

Permanganate

Crystal

90-100

Oxidizer

Odor Containers

Ivory

N/A

Dark Brown, N/A
Yellow-Brown

Red-Brown N/A

Green N/A

White, Green- N/A
Yellow

Blue, Dust
White

White N/A

Blue None

Light Orange None

Purple None

Bags, Tank
Truck, Bulk

Carboys, Tank
Cars

Bags, Drums

Bags, Drum?.
Bulk

Bags, Bulk

Bags, Carboys.
Tank Trucks

Bags, Drums

Tank Truck.
100 lb. Drums

Drums, Bulk

ERIC

433

Safety 413

When handling, stonng or preparing solutions of chemi-
cals, treat them all as being hazardous. All chemicals require
careful consideration. They may be sources J an explosion,
violent reaction, loss of eyesight, burns and illness.

Do not store acid or oasic compounds with salts. Keep
these chemicals in e clean, dry area. When handling dry bulk
matenals, store in a fire-safe area. Keep all lids on contain-
ers "^nd follow the instructions on the container Make sure
that the operator who is mixing or dispensing these chemi-
cals is well trained and wears proper clothing to meet all
safety requirements, such as chemical goggles, face shield,
rubber gloves, rubber boots, rubber apron and chemical
respirator. When working with chemical salts, be aware that
fumes, gases, vapors, dusts or mists may be given off and
this represents a hazard to the safety of the operator.
PROTECT YOURSELFf

20.140 Aluminum Sulfate (alum)

There are two forms of alum; dry and liquid. Both have to
be handled with care. Dry alum is available m the lump,
ground or powdered form and should be stored in a dry
location because moisture can cause caking. Liquid alum is
acidic and very corrosive. Store liquid alum in corrosion
resistant storage tanks such as:

1. Steel, wood (Douglas Fir), or concrete-iined, all lined with
8-lb lead.

2. Steel, lined with 3/16 mch (5 mm) soft rubber,

3. Stainless steel.

4. Steel, lined with plartic if temperature remains below
150°F (65°C), and

5 Glass reinforced epoxy or polyester plastic.

When working with dry alum, use respiratory protection
and ensure adequate ventilation of the work area. There
should be a good mechanical dust-collection system to
minimize any dust collection.

Exposure to alum dust greater than 15 milligrams per cubic
meter of air for more than an 8-hour period is dangerous.
Avoir' skin exposure to this rhemical by using long-sleeved,
loose fitting, dust-proof clothing.

Liquid alum is an acidic solution and should be handled as
you would handle a weak acid. Reduce exposures to the
skin and eyes Avoid ingestion. Although the chemical will
not cause any lasting internal damage, it will be uncomfort-
able Use good ventilation for removing any mists. Rubber
gloves and protective clothing is recommended.

As a general precaution, avoid prolonged exposure to dry
or liquid forms of alum. If used dry, a dust mask and goggles
are desirable for the comfort of the operator. Alum dust can
be extremely irritating to the eyes. When handling the liquirJ,
normal precautions should be used to prevent splashing of
the compound onto the operator, particularly ' the liquid is
hot Wear a face shield to protect your eyes and a rubber
apron to protect clothing.

ERIC eti*

First aid for liquid or dry alum is immediate flushing of the
eyes for 15 minutes with large amounts of water. Alum
should also be washed off the skin with water because
prolonged contact will cause irritation.

20.141 Ferric Chloride

This IS a very corrosive compound and should be treated
you would treat a.ny acid. The salt is highly soluble *n
water, but in the presence of moist air or light, -it decom-
poses to give off hydrochloric acid, which may cause other
problems regarding safety. Avoid prolonged exposure to
this liquid (there is a dry form but it is not often used). When
handling liquid ferric chloride, normal precautions should be
taken to prevent splashing, particularly if the liquid is hot.
Use a face shield to protect your eyes and rubber aprons to
protect clothing. This compound will not only attack the
clothing, but also stain it. First aid for eyes exposed to the
liquid IS that the eyes must be flushed out immediately for 1 5
minutes with large amounts of water. Ferric chloride should
also be washed off the skin with water as prolonged contact
will cause irritation and staining of the skin.

20.142 Ferric Sulfate

This compound produces an acidic solution when mixed
With water. Because of Its acidic nature, operators using this
compound should be provided with protection suitable for
dry or liquid alum. The hazards associated with the use of
dry ferric sulfate are those usually connected with an acid.
Use protective clothing, neck cloths, gloves, goggles or face
shield, and a respirator. Avoid prolonged exposure to the
dry form because of its acidic reaction with moisture on the
skin, eyes and throat. The normal precautions should be
used including a dust mask and protective clothing. First aid
for exposure to the eyes requires the eyes to be flushed
immediately with lot*^ ' water. The skin should also be
flushed with large amounts of water. Prolonged contact may
cause irritation.

20. 143 Ferrous Sulfate

This chemical may be obtained in liquid or dry form. The
safety hazards are some of those for dry or liquid forms of
alum The operator should be provided with adequate venti-
lation and respiratory protection The material should be
stored in a clean, dry location. Mechanical dust collecting
equipment must be used to minimize the dust. Wear chemi-
cal goggles or a face shield, loose fitting, long-sleeved
clothing, and make an effort to minimize all skin exposure.

First aid for ferrous sulfate in the eyes is to flush out
immediately with large amounts of water for 1 5 minutes. The
chemical should be washed off the skin to reduce irritations.

20. 144 Sodium Alumir)ate

Sodium aluminate dissolved in water produces a non-
corrosive solution. In the dry form, its powder consistency
raises the usual dust problems. There are few hazards with
this compouno, but as with other chemicals, you should use
precautions when handling it. Use respiratory protection
when handling the dry compound to prevent the inhalation of
dust First aid for eyes that are exposed is to flush with
water; keep the skin clean with water.

20.145 Fluoride Compounds

All fluoride compounds should De treated with care when
you are handling them because of their long term accumula-
tive effects. Provide good ventilation; always wear respira-
tory protection; and be careful not to expose any open cuts.

434

41 4 Water Treatment

lesions (wounds), or sores to fluoride compounds Clean up
any spills promptly ano wash immediately after handling
such compounds.

When handling acui compounds of fluonde, always wear a
face shield and/or chemical goggles, ruboer gloves, rubber
apron and rubber boots. Your weanng apparel should
always be washed after working around fluoride, and the
resDirator should be kept cle.in and sanitary Keep the ac»d
feeder for fluonde in good repair. Use plastic guards to
prevent acid spray from glands or other parts of the chemi-
cal feeder This prevents attack upon the equipment and
protects operators All fluoride compounds must be regard-
ed as hazardous chemicals that are toxic to operators. Every
means possible must be taken to prevent exposure to these
compounds by use of resp'rator and protective clothing.

First aid for fluoride compounds is limited, but the follow-
ing precautions should be used. For the eyes, flush immedi-
ately with warm water and consult a physician. For external
injuries, wash with large amounts of warm water. For
poisoning, the victim should dnnk a glass of lime water, or a
one percent solution of calcium chloride, or a large amount
of milk. See a doctor

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 439.

20 14A What kind of protection does an operator need
when handling salts?

20.14B What IS the recommended first aid when either
liquid or dry alum comes in contact with your skin or
your eyes?

20 14C Whal happens when ferric chloride is exposed to
moist air or light''

20.15 Powders

20, 150 Potassium Permanganate (KMnO^)

Under normal conditions in a water treatment plant, potas-
sium permanganate js considered to be a safe chemical.
However, potassium permanganate is a strong oxidizing
agent and will react with certain easily oxidizable sub-
stances. Keep potassium permanganate away from the
possibility of reacting with sulfuric acid, hydrogen peroxide,
metallic powders, elemental sulfur, phosphorus, carbon,
hydrochlonc acid, hydrazine, hydroxylamine, and metal hy-
drides. When in contact with potassium permanganate, the
following compounds may ignite: ethylene glycol (anti-
freeze), glycerine, sawdust compounds, propylene glycol,
and sulfuric oxide.

Potassium permanganate Is available either as pellets or
as a powder. This chemical can be kept indefinitely if stored
in a cool, dry area in closed containers. The drums should be
protected from damage that could cause leakage or spillage
Potassium permanganate should be stored in fire-resistant
buildings, having concrete floors instead of wooden floors.
The chemica' must not be exposed to intense heat, or stored
next to heated pipes. Organic solvents, such as greases and
oils, should be kept away from stored potassium perman-
ganate.

Potassium permanganate spills should be swept up and
removed immediately. Flushing with water is an effective
way to eliminate spillage on floors. Potassium permangan-
ate fires should be extinguished with water.

er|c

To avoid inhalation of potassium permanganate dust, use
an approved mask wh.ch is an air-punfying half-mask respi-
rator with an outblower Safety glasses or a full face shield
should be wom to protect your eyes. Protective clothing that
should be worn includes rubber or plastic gloves ^nd apron,
and a long-sleeved shirt for handling both dry and dissolved
potassium permanganate.

Mjirj exposu*'*? w!^! cause sneezing and mild irritation of the
mucous membr<.nes Prolonged inhalation of potassium
permanganate should be avoided. If potassium permangan-
ate gets on your skin, flood the contacted skin with water If
It gets in your eyes, flush with plenty of water and call a
physician immediately.

20, 151 Powdered Activated Carbon

Powdered activated carbon is the most dangerous pow-
der that you will be exposed to as a treatment plant
operator. If you understand how to handle activated carbon
properly, other dust problems or powdered chemicals will
not be very difficult for you to handle.

There are two problems when handling activated carbon.
One IS dust and the second is fire. The two may or may not
be related. The dust causes uncomfortable working condi-
tions; fire causes damage to equipment and a hazard to
personnel. If the two problems are treated together, it will
reduce the hazards to operators. Left unattended they may
cause loss of life and property. If you will use the following
safety precautions, you can minimize the hazards of han-
dling activated carbon and aid the other operators in han-
dling other powders.

Store activated carbon in a clean, dry, fireproof location.
Keep free of dust, protect from flammable materials, and do
not permit smoking m the area at any time when handling or
unloading activated carbon. Install carbon dioxide fire extin-
guishers. Store bagged carbon in single rows. Keep access
aisles free to prevent damage to the bags and thus reduce
the dust and fire potential.

Electrical equipment in and around activated carbon stor-
age should be explosion proof and protected from the
carbon dust. Keep the equipment clean and dry. Wet or
damp carbon is a good conductor of electrical current and
can cause short-circuit fires Heat can also build up from the
motors if covered with carbon dust, causing fires. The key to
controlling fires with activated carbon is keeping the storage
area clean and dust free.

Next to electrical fires, activated carbon gives the operator
the frost difficult fire to control. The carbon gives off an
intense heat; it burns without smoke or visible flame. The
fires are difficult to locate and are very hard to control. They
cannot readily be detected in a large storage bin or in large
stacks of bags.

You will detect the indications of the fire before seeing any
evidence of flames, such as the smell of charred paper,
burned paint or other odor.

Do not douse a carbon fire with a stream of water. The
water may cause burning carbon particles to fly, resulting In
a greater fire problem. The carbon fire should be controlled
with carbon dioxide (COg) extinguishers or hoses equipped
with fog nozzles. However, when using COg, be aware that
there is a potential of carbon monoxide formation and

435

Safety 415

take the precaution of using a self-contained breathing
apparatus

Activated carbon supports fire without atmospheric oxy-
gen because it may have absorbed sufficient oxygen for
combustion. The best means of controlling a carbon fire is to
reduce its temperature below the ignition point. This can be
done by applying cold water with fog or spray nozzles and
soaking the burning carbon, but do not hit the carbon with a
stream of water. If the fire is small, just a few bags, they
should be ren oved to a safe location and dealt with by COg
or spray nozzles Blocks of dry ice can be used to control
fires in storage bins or other confined areas, but do not
expect this method to be very effective.

A final word about fire and explosions involving activated
carbon. Tests performed by carbon manufacturers have not
shown that dust mixtures of carbon have explosive tenden-
cies. Activated carbon is a charcoal and performs in a like
manner, the carbon burns withOui smoke or visible flame,
burns very hot, and will spread if doused wiih a large stream
of water

There are no specfic first aid methods for carbon expo-
sure because the carbon will not attack the human body.
Carbon does sometimes cause problems with the nasal
passages, however, and may be difficult to wash off your
hands and body. Therefore, methods h3re are those of
prevention Provide good dust collection at the point where
carbon is being unloaded, in storage bins for liquid prepara-
tion, and in dry storage bin«^. Wear an approved dust mask,
loose fitting and dust-proof clothing. If there is an excess of
dust, you should use chemical goggles, close your 'ihirt
collar and tape your trousers to cover your ankles. Yo i wi!!
need adequate shower facilities and should use mild liquid
soap. Most, if not all, hard soap bars are ineffective in
removing activated carbon dust from pores of the human
body.

20. 152 Other Powders

You may come m contact with other powdered com-
pounds in the water treatment plant, but they do not present
the problem in handling that activated carbon does. Benton-
ite creates no significant hazard other than dust, and this
can be controlled by using dust collection systems.

Similarly, calcium carbonate presents a slight dust hazard
that can be controlled by a dust collection system. Also,
whe'i handling calcium carbonate in bags, use the same
methods of control that you would use with bags of caibon

Of thR many organic coagulant aids used in water treat-
ment, only a few are applied in powder form Most of these
compounds are used in the liq'iid form which reduces the
danger in their use to operators. The dry compounds pre-
sent a slight hazard in dust irritation to the nasal passages,
this can be prevented by use of approved dust masks. The

liquid coTipounds can and will attack .f-.c skin, but can be
treated by washing with ample amounts of water and/or
soap and water Organic coagulant aids (polymers) are
extremely slippery when wet. Floors and walkways should
be clean and dry to prevent slips and falls.

As new compounds are introduced to the waterworks
field, ask for training in their use Such a training program
should provide information about detailed safety precau-
tions, the toxicity of the compound, and the appropriate first
aid methods Supervisors have the responsibility to provide
this type of training, either in conjunction with the supplier or
sponsored entirely by the utility The training must be
reinforced periodically for those compounds that are not
often used by the operator A review and updating of
information will go a long way in preventing accidents

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 439

20 15A How can potassium permanganate spills be
cleaned up'?

20 15B What is the most dangerous powder the water
treatment plant operator will be exposed to'?

20 150 How should activated carbon be stored'?

20 15D How can fires caused by activated carbon be pre-
vented'?

20 15E How should an activated carbon fire be extin-
guished'?

20.16 Chemical Storage Drains

Safety regulations prohibit the use of a common dram and
sump for acid and alkali chemicals, oxidizing chemicals and
organic chemicals because of the possibility of the release
of toxic gases, explosions and fires If both an acid and an
alkali chemical come in contact, an explosion could occur. If
an organic chemical such as a polymer solution comes in
contact with an oxidizing chemical such as potassium per-
manganate, a fire could develop Be sure that if a leak
develops from any chemical container or storage facility, the
chemical will not be able to reach, mix or react with another
chemical

QUESTIONS

Write your answers in a notebook \^d then compaie your
answers with those on page 439,

20 1 6A Why should drains from chemical storage areas not
use comnon drains and sumps?

20.16B What co'Jid happen if a leak from a polymer storage
container comes in contact with potassium perman-
ganate'?

end ^ U44a%2 M imm

436

416 Water Treatment

DISCUSSION AND REVIEW QUESTIONS

Chapter JO. SAFETY

(Lessor 2 of 4 Lessons)

Write the answers to these questions in your notebook
before continuing. The problem numbenng continues from
Lesson 1

9 What does an operator need to know about chemicals
used In a water trt aiment plant*?

10. How can hydrochloric acid be hpndled safely*?

1 1 How should hydrochloric acid be stored?

12. How can ammonia leaks be detected?

13. What IS the I'irst aid treatment for lime burns'?

14. What special precautions should be taken when han-
dling and storing caustic soda*?

15. How should hypochlorite be handled and stored*?

16 What first aid is required for a person overcome by
carbon dioxide?

1 7 What safety hazards may be causer^ by salt dust*?

18 What types of safety hazards might an operator en-
counter when handling alum?

19 What are the two major problems encountered when
handling activated carbon*?

20 How can an operator detect an activated carbon fire?

ERIC

Safety 417

CHAPTER 20. SAFET\

(Lesson 3 of 4 Lessons)

20.2 FIRE PROTECi ION

20.20 Fire Prevention

Fire prever tion is the best fire protection the plant opera-
tor can afford. Fire protection is just good housekeeping.
The word "housekeeping" best descnbes the action any
water plant operator can take to protect from or prevent
fires. This means a well-kept, neat and orderly plant repre-
sents a good fire bdfety policy. Fire hazards can be easily
removed. The prompt disposal of cartons, crates and other
packing materials, a system of waste paper collection, and
the removal of other debris can greatly reduce fire hazards.
Provide suitable containers for used wiping cloths and have
fire extinguishers conspicuously located in hallways, near
work areas and near potential fire problem areas. All of
tnese housekeeping activities are low-cost measures that
also improve the appearance of the plant and create a better
work environment.

You can call upon the service of the local fire department
for advice on fire prevention in and around the treatment
plant. You may also ask the utility insurance underwriter for
cooperation In your fire prevention program. All operators
should be trained in the proper use and maintenance of fire
control equipment. These simple steps can reduce fire
losoes to a minimum and prevent most fires from happening
at vary lov cost to the utility.

You should make a fire analysis of your plant once a year
to determine what new measures should be taken to prevent
fires. As activity changes occur, there may be a need to
change the location of hoses and extinguishers or it may be
necessary to add fire control equipment. Fire and police
departments' telephone numbers must be posted in ? con-
spicuous location along wlt^^ escape routes. Post emeigen-
cy numbers near all telephones throughout the plant. In
hazardous locations the means of oxit should be lighted and
all doors equipped with "panic bars." As indicated above,
your best fire protection or prevention is good housekeep-
ing.

20.21 Classification

Fire classifications are important for determining the type
of fire ex*'nguisher needed to control the fir. . Classi.ications
also aid .n recordkeeping and for comparison with other
agencies. Fires are claosified as ''A" — Ordinary combusti-
bles, '*B" — Flammable liquids, — Electrical equipment,
and "D" — Combustible metals.

A Class A fires involve miscellaneous combustible materi-
als These include fabrics, paper, wood, dned grass, hay
and stubble.

B. Class B fires involve flammable liquids and vapors. This
may include oils, lacquers, fats, waxes, paints, petroleum
products and gas This class is subdivided into two

subclasses:

B-2 - are those fires in which the source of flammable
vapors is substantially in a single place such as
tank's, vats, spills and trenches.

B-3 - are those fires that are complicated by a falling
stream. LPG and other vapor fires are in this class.

C The Class C fire involves electrical equipment such as
starters, breakers and motors. The circuits should always
be killed before extinguishing this type of fire.

D. Class D fires involve metals such as sodium, zinc, mag-
nesium and other similar metals. Operators rarely en-
counter this type of fire.

2';.22 Extinguishers

There are many types of hand-held fire extinguishers. All
are classified for class of fires. There is no one extinguisher
that IS effective for all fires, so it is important that you
understand the clas.s of fire you are trying to control. You
must be trained in ...a use of the different types of extin-
guishers, and the proper types should be located near the
area where that class of fire may ocour.

A. There are four types of water extinguishers: stored
pressure, cartridge operated, water pump tank, and
soda-acid. All of mese perform well in Class A fires, but
they do require maintenance. A preventive maintenance
schedule on all water extinguishers should include a
monthly check by the operator responsible for the riain-
tenance and completion of appropriate maintenance rec-
ords. Some agencies make the safety officer responsi-
ble for ensuring t*iat an ope.ator checks the fire
extinguishers.

1. The method of operation for a stored p»'essure extin-
guisher IS simply to squeeze the handle or turn a valve.
The maintenance is also simpie: check air pressure,
record and recharge the extinguisher as needed.

2. For the cartridge type, the maintenance consists of
weighing the gas cartndge and adding water as re-
quired. To operate, turn upside down and bump.

3 To use the water pump tank type of extinguisher,
simply operate the pump handle. For maintenance,
one has only to discharge the contents and refill with
water annually or as needed.

4. The soda-.' td type r jst be turned upside down to
operate; it also requires annual recharging.

B. The foam type of extinguishers will control Class A and
Class B fires well. They, like soda-acid, operate by
turning upside down and require annual recharging.

The foam and water type extinguishers should not be
used for fires involving electrical equipment. However,

4S8

418 Water Treatment

they can be used in controlling flammable liquids such as
gasoline, oil. paints, grease and other Class B fires.

C The carbon dioxide (CO^) extinguishers are common
(Figures 20.6 and 20.7). They are easy to operate, just
pull the pin and squeeze the lever For maintenance, they
must be weighed at least semi-annually. Many of these
extinguishers will discharge with age. They can be used
on a Class C (electrical) fire. All electrical circuits should
be killed. If possible, before trying to control this type of
fire. A carbon dioxide extinguisher is also satisfactory for
Class B fires, such as gasoline, oil and paint, and may be
used on surface fires of the Class A type.

D. There are two types of dry chemical extinguishers. These
extinguishers are either (1) cartrMqe operated or (2)
stored pressure. These are recom.nended for Class B
and C fires and may work on small surface Class A fires

1 . The cartridge-operated extinguishers only require you
to rupture the cartridge, usually by squeezing the
lever The maintenance is a bit more difficult, requiring
weighing of the gas cartridge and checking the condi-
tion of the dry chemical.

2 For the stored-pressure extinguishers, the operation
IS the same as the CO^ extinguisher. Just pull the pin
and squeeze the lever. The inte nance requires a
check of the pressure gages arid condition of the dry
chemical

As suggested above, a preventive maintenance program
for fire extinguishers requires a considerable amount of time
from the operator and requires a system of recordkeeping

You might consider hiring a local fire prevention agency to
perform this part of your maintenance piogram. These
service agencies will check and maintain the plant's fire
fighting equipment on a regular basis. This does not relieve
the operator of ultimate responsibility for the equipment, but
assures that the equipment is in proper working order when
needed

20.23 Fire Hoses

Fire hoses are usually stationed throughout the treatment
and pumping plants. These are the type of fire fighting
equipment that an operator may see every day, but never
give due consideration to their maintenance. Without proper
maintenance, the hoses may develop dry rot and be un-
trustworthy at the time they are needed. Under some condi-
tions, you may be tempted to use these hoses for cleaning
settling basins or filters. The fire hoses should only be used
for fighting fires, and after their use, they must be cleaned
and stored properly The hose should be tested periodically
and replaced as required, or at regular time intervals. Check
with the local fire department for recommendations.

[SPECIFICATIONS

322

CARBON DIOXIDE

Size/Type

Horn

; 10
! Hose

i
1

15
Hose

20
Hose

Model Number

'"'322

331

33"2

U/L Rating

SBC

10BC

Capacity (lbs )
Shipping V\t i^bs )

15 '

To'

] 29' r

39T2

i 51 V2

Height

30"

^- - J

30"

'vVWfh'

\2"

12'

Depth (Diam) ~

Range {Ft )

" ~ 3-8

3-8

3-8 ~j

Discharge Time-
Seconds

12 5

Coast Guard App ; Yes

[ Yes

-I—

Yes

" Yes

<S> Approved
Bracket

Yes

~j Yes
\ vvair '

Yes

Ves™"
V^^ll '

tg. 20.6 Carbon dioxide extinguishers

(Permssion of Nevada Safety & Supply)

Er|c 439

Safety 419

442 425 41 7T 424 419 441 423

SPECtFtCATlONS

ABC

Size/Type

No22le

Noz2le

Nozzle

Hose

10 Short
Hose

10 Tall

Hose

20 "
Hose

Model Number

417T

425

442

424

419

441"

^"423"

U/L Rating

1A:10
B:C

2"a:To
B.C

3A.4d'
B.C

"2A:T6"
B:C

1a.60
B:C

^A:60'
B:C

20A.'l2b
B.C

Capacity (ibs.)

2V2

Ship. Wt. (lbs.)

5V2

10^/2

19V2

46~_

Height

14"%"

14%"

17"

20 V2""

"24 "

Width

3%"

9'/^j"

10"

Depth (Dtam.)

~4 y4

4V4"

-----

Range (Ft.)

9-T5'

"12T8^

""12-18

12-78"

15-21

D.scharge Time-
Seconds

Coast Guard Ap.

~~Yes ~ ^

~~Yes

Yes

^Ye~

<3> Approved

YeT

Yes '

Pend.ng

Yes

Bracket

Veh/Mar

^Wafl '

Wall

Wail

Wall

f\Q. 20.7 Typical carbon dioxide extinguishers

(Permission of tJevada Safety & Supply)

20.24 Flammable Storage

The storage of flammable material should be isolated, if
possible, from other plant structures Ideally, these storage
areas should have explosion-proof lighting. The floor should
be grounded and the operator should only use sparkproof
tools when working near or handling flammable materials.
The room should have an alarm system, be equipped with
automatic extinguishers and have supplementary equipment
located outside of the room. In and around the storage area,
smoking or welding must be prohibited. The flammable
storage areas must be cleaily marked with distinctive signs
and all entrances should be lighted.

More often than not, however, you will be compelled to
use rooms within the plant for storage of flammable material
Here you must make the room fireproof, equip the room with
a fire door, automatic extinguishers and alarms. Keep pas-
sageways free from obstructions. Station fire-fighting equip-
ment at a suitable location, readily accessible and with

plainly labeled operating instructions The room must be
equipped with explosion-proof lights, grounded floor, no
smoking permitted, and distinctive signs indicating that this
room IS a flammable storage area.

20.25 Exits

Access and "^xit are very important in plant safety There-
fore, all exit jns should be distinctly marked and well
lighted All doors should open outward and, in hazardous
areas, there should be "panic bars" on the doors To provide
positive protection around the filter and sedimentation ba-
sins, install hand rails or other enclosures for the protection
o' operating personnel as well as visitors.

In hioh-fire-hazard occupied areas, there should be at
least two means of emfgency exit located, if possible, at
opposite ends of the room or building. These would include
areas containing woodworking and paint spraying residues
that burn rapidly or give off poisonous fumes.

440

420 Water Treatment

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 439.

20 2A Class A fires involve what types of materials'?

20.2B What kinds of fires can be controlled by a foam type
of extinguisher'?

20.2C How can an electrical fire be extinguished'?

20.3 PLANT MAINTENANCE

20.30 Maintenance Hazards

Plant maintenance, housekeeping, cleaning up, or what-
ever you wish to call it, is a very important function of the
treatment plant and essential for plant equipment. This
function requires the use of cleaning materials and hand
tools Maintenance may require you to go into a manhole,
•-epair electncal motors, lift boxes and use power tools. All of
these functions may in some way be hazardous, and if not
given proper consideration, may cause injury, fire, disease
or even death.

20.32 Painting

There are a number of considerations when painting in a
treatment plant. First, is the paint exposed to the drinking
water being treated and are there toxic compounds in the
painf? Next, is the paint being applied by brush or spray? In
either case, is there sufficient ventilation if the operator is
painting indoors or in a closed area'?

When working with toxic paints, for example, those con-
taining lead, zinc, or organics, be sure to clean your hands
before eating or handling food. Also, avoid exposing your
skin to solvents and thinners and try not to use compounds
such as carbon tetrachloride. When spiiy painting, always
use a respirator to avoid inhaling fumes. Do not allow
smoking or open flames of any kind around areas being
painted. Also, when painting or cleaning the spraying equip-
ment, avoid closed containers where heat is involved. At a
certain temperature called the flash point, spray or vapors
could ignite and burn the operator or start fires. Always
clean the spray equipment In an area having sufficient
ventilation If the painting operation Is taking place in a paint
booth, use only explosion-proof lighting and permit no open
flame and no electric switch that may cause a spark.

20.31 Cleaning

Any effort spent keeping the entire plant clean and sani-
tary will provide a much nicer place for you to work and will
also make visitors feel as if the water being produced is
safe. Even if you car just keep all working areas free of
tnpping hazards, thr .v^ill add greatly to the safety in the
plant

Cleaning duties should be performed at such times of day
or night as to cause a minimum of exposure to other
operators. For example, floors become slippery when wet
so give some consideration to the time of day and the type of
wax to be used. When cleaning floors, there are problems of
exposure to others of cleaning equipment, mops, mop and
broom handles, other tools, cleaning compounds, and most
of all, wet floors. When cleaning, try to keep others out of the
area Warn others about newly waxed floors. Use wax
compounds containing nonslip Ingredients. Try to do such
cleaning and waxing during off-duty hours, weekends or at
night.

As part of >jur maintenance program, prOvjde trash
containers for collecting waste paper and for separating
used, oily rags. Dispose of garbage and flammable refuse
on a routine, frequent basis. Hazardous waste, acids and
caustics should be cleaned up immediately. These steps will
add to the safety in the plant and to the safety of operators in
the plant.

Keeping aisles, doorways, stairs and work areas free of
refuse reduces hazards of tripping and other injuries, as well
as reducing the possibility of fires.

Cleaning windows is a hazardous occupation, but the
operator who gives due consideration to the task can
perform it safely. If windows are high, time of day is
important. Cleaning tools may be dropped and fall on
pedestrians or vehicles. There may be a need for safety
harnesses; check the harness each time it Is used. Make
sure all parts of the harness are in good working condition.
Cleaning compounds that are acid or alkaline may attack the
harness or the safety rope. Also, such compounds may
attack human skin: therefore, use rubber gloves when
appropriate.

hiiiinniimrfTnaaia

Some of the other hazards when painting include scaffold-
ing, rags and threats to your personal health. Be very careful
when using scaffolding and ladders. The scaffolding must be
in good repair and conform to current safety regulations.
Ladders must also be in good repair. If they are broken or
badly worn, they should be replaced with new ones.

Rags are always a problem If they contain oils, paint or
other cleaning compounds; there is always the possibility of
fire. The rags should be placed into a closed netal container
to reduce the fire hazard.

As to personal protection, consider using creams to help
reduce skin exposure to paint and solvents. Always <'se an
approved respirator to reduce inhalation of fumes and paint
♦s. As a final note, avoid any unnecessary exposure to
. or solvents to the skin.

20.33 Cranes

Overhead traveling cranes require safety considerations.
First, only authorized personnel should be allowed to oper-
ate them. Inspections should be made to check out the
circuit breaker, limit switches, the condition of the hook, the
wire rope and other safety devices. The load limits should be
posted on the crane and you should never overload the unit.
Always check out each lift for proper balance. U«8 only a
standard set of hand signals, and make sure that each
operator involved with the crane knows all of the signals.
Personnel In and around an overhead crane should be
required to wear hard hats. When making repairs to the
crane lock out the main power switch and allow only
authorized personnel to make repairs.

441

Safety 421

Never move loads over areas where operators or other
people a'^e working. Do not let the load remain over the
heads of operators or other workers or allow them to work
under loaded cranes. If loads must be moved over populated
areas, give a warning signal and make sure everyone is in a
safe location. Set up monthly safety inspection forms to be
filled out and placed into the maintenance file. The plant
supervisor should review the forms and authorize any
maintenance necessary on the crane in addition to following
a good preventive maintenance program.

20*34 Manholes

There are mr'^y hazards involved with manholes and all of
them can cause injury to the operator. Just removing the
manhole cover can cause the loss of hands or fingers. You
should never remove the manhole cover with your hands.
Use a manhole hook or special tool such as a pick with a
bent point to remove the lid. Be very careful when lifting the
lid. Use your legs, not your back for lifting. This will help
prevent back strains. Locate the cov tslde the working
area to provide adequate working area jnd the manhole
opening.

Next IS the problem of traffic around an open manhole.
The public, other operators and vehicles must be protected.
Therefore, barncades, warning devices and lights must
conform to local and state regulations. There also should be
a barricade around the manhole to protect the operators. All
personnel around manholes should wear hard hats for their
safety.

Always inspect the ladder rungs in the manhole before
using them. They may become loose or corroded and
therefore should be tested, using your own weight. One
should never enter a manhole i-Ione; there should be at least
one other person standing by at the top and at least one or
more people within hearing distance in case of injury.

Perhaps the greatest threats to operators working in
manholes are air contamination or depletion of oxygen.
Many operators have lost their lives because of leaking gas
mams, decaying vegetation or other gases. Never enter a
manhole without checking the atmosphere for (1) sufficient
oxygen, (2) presence of toxic gases (hydrogen sulfide), or (3)
explosive conditions (methane or natural gas). In any event,
always provide adequate ventilation. This will remove any
hazardous gases. To check the safety of the atmosphere In
a manhole, use a gas-detection Instrument (Figure 20.8).
These devices can detect explosive gases, oxygen deficien-
cy, and/or toxic conditions. Remember, just because there
are no toxic or explosive gases present does not mean that
you may not lose your life because of a deficiency of oxygen.
Normal air contains about 21 percent oxygen. The first
effects of insufficient oxygen occur when the oxygen con-
tent drops to about 15 percent. Operators who work around

rr.dnholes should be trained in applying artificial respiration
(C.P.R ).

Smoking should nc be permitted in or around man-
holes. Always use a mechanical lifting aid (rope and bucket)
for raisi.ng oi lowenng tools and equipment in and out of a
manholo The use of a bucket or bJ»<- ket will keep your hands
free when climbing down into or out of the manhole

To review the hazards of underground structures, remem-
ber to give consideration to proper tools for opening and
closing the manhole. Keep in mind the need for barricades
and lights to warn traffic and to prevent endangering other
operators. Be sure that operators are trained in artificial
respiration methods and in the way to test the manhole for
oxygen, explosive and toxic gases.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 439.

20.3A What safety precautions should be taken when wax-
ing floors?

20.3B How should rags containing oils, paint or other
cleaning compounds be stored?

20. 3C What safety precautions should be exercised when
operating an overhead crane?

20 3D How can traffic be warned that operators are work-
ing in a manhole?

20.3E How should tools and equipment be lowered into and
removed from manholes?

20.35 Power Tools

The two general classes of portable power tools are (1)
pneumatic md (2) electrical. Safety precautions for handling
these types of tools are much the same for both types. Wear
eye and ear protection when operating gnndlng. chipping,
buffing, or pavement breaking equipment. Sometimes when
using grinding or buffing tools you will encounter toxic
materials and, therefore, will need respiratory protection. At

422 Water Treatment

other trmes there is a need for full face protection because of
fiying particles: you should use a face shield or at least
goggles In the use of electrical loots, always replace worn
out extension core* and never expose cords to oils or
chemicals Extension cords also present a tripping haz^ird if
left in the way Avoid leaving extension cords in aisles o» in
work areas Do not hang extension cords over sharp edges
which could cut the cord and always store the cords in a
clean, dry location When working m a wet or damp location,
some consideration should be given to the use of rubber
mats or insulated platforms. As indicated above, use only
grounded tools. When using pneumatic tools, never use the
compressed air to clean off your clothing or parts of your
body Air can enter your tissues or other openings and
cause problems Always check hose clamps. If they are
loose or worn, tighten or replace as needed. Air hoses, like
extension cords, are a tripping hazard. Therefore, consider
tneir location when working with pneumatic tools For the
large (3/4 inch or 18 mm) hoses, always use an approved
safety-type hose connection with a short safety chain or
-ither safety device attached. Air hoses that come apart can
cause injuries as they are whipping about. Like electrical
cords, krep air hoses away from oils, chemicals or sharp
objects.

Sandblasting, using a pneumatic tool, requires some
special consideration. The operator should protect all skin
surfaces with protective clothing, wear eye and face protec-
tion, use a respirator, and be very careful of toxic fumes
which are discharged from a blasting operation

The grinding wheel, pneumatic or electric, requires the
same safety considerations. Eye and face protection is
required. Do not use this tool without safety guards Be
careful of gloves being caught on the grinding wheei. Never
operate a wheel with loose nuts on its spindle. When the
grinding wheel is badly worn, replace it and use the proper
wheel and speed of rotation.

All persons using power tools must be trained in their use
and maintenance. Use the manufacturers operations and
maintenance guide for details of proper training. Most
injuries by power tools are caused by incorrect setup and
operation due to poor training.

Finally, a high level of noise is frequently encountered
When operating power tools. For example, air drills produce
95 dB^ and circular saws 1^5 jb. Ear protection must be
provided when exposed t-^ long periods of high levels of
noise. In areas of noise exposure, all operators should be
provided with approved ear protective devices.

20.36 welding

The first safety rule in operation of gas or electric welding
equipment is that the operator be thoroughly trained in the
correct operating procedures. The second rule concerns fire
protection. The third rule is personnel protection. None of
these rules is first or last — they should ALL be followed.

If you are not thoroughly trained in the use of the welding
equipment, do not use it. If you absolutely must use the
equipment, do so only under the supervision of a trained
welder. Whenever such work must be performed in or
around a water treatment plant, take time to consider the fire
problem. For example, welding can be very dangerous in an
oxidizing chemical location, near powdered activated carbon

storage, and in storage areas for other bagged chemicals.
Avoid welding around oil and grease when possible, and
when that's not possible, at least provide for ventilation of
fumes. When welding or cutting is done in the vicinity of any
combustible material, you must take special precautions to
prevent sparks or slag from reaching the combustible mate-
rial and causing a fire

Regarding the safety of other personnel in the welding
area, eye protection comes first The person using the
welding equipment must wear protecti'3 clothing, gloves,
helmets and goggles Others in and around the welding
operation should be kept at a safe distance. Always be
careful of overhead welding because of falling sparks and
slag If other operators are (or itiust be) working in the
vicinity of the welding operation, they too must be pr *ected
from the rays of arc welding, never look at the welding
operation without eye protection.

The storage of welding gas cylinders should be given the
same consideration as those of other gases in water treat-
ment. They are stored upright, kept out of radiation of heat
and sunlight and stored with protective covers in place when
not in use. Store cylinders away from elevators and stairs,
and secure them with a chain or other suitable device.

20,37 Safety Valves

There are quite a number of safety valves in a water
treatment plant, operators are not always aware of their
locations or functions For example, most operators know of
the safety plugs on chlorine cylinders, but the''e are also
large safety valves in any plant that stores large amounts of
chlorine on site. These containers take on truck load lots of
17 tons (15.540 kilograms). The safety valves on such
containers should be certified at least every two years or as
often as the state requires. Such relief valves must be
maintained on a regular basis. Inspect the inside of these
tanks at regular time intervals and keep a record of the
findings, for example, evidence of deposits and corrosion.

Water heater safety valves should be checked on an
annual basis end maintained or replaced as needed. If the
plant has a boiler room, the steam safety valve should be
maintained and checked for proper operating pressures.
These valves should not discharge in such a manner as to
be a hazard to operating personnel.

There also may be surge relief valves on discharge piping
(high lift) of the treatment plant. These valves also act as a
safety valve to the pumping equipment and must be main-
tained on some regular time Interval. Tney should be
checked for proper pressure setting, with a" pilot valves
being reconditioned or replaced as needed.

There may be other safety valve located in ihe pumping
plant's hydraulic system for opening and closing discharge
valves that require maintenance. In the maintenance of
water treatment plants, you or your supervisor must set up a
maintenance system for all equipment. Hand tools, power
tools and other maintenance equipment must also be kept m
safe working condition. Operators must be furnished protec-
tion for the eyes, the ears, the hands, the head, feet and at
other times, the body. Work areas should be well ventilated
and noise should be reduced whenever possible. Each
operator should always be on the lookout for additional
ways of making the treatment plant a safer place to work.

5 Decibel (dB) (DES-uh-buH) A unit for expressing the relative intensity of sounds on a scale from zaro for the average least perceptible
sound to about 130 for the average level at v\/hich sound causes pam to humans, T

Safety 423

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 440

20 3F What type of protection do operacors need when
operating portable power tools'^

20.3G How can operators be protected from high noise
levels when operating air dnils and circular saws'?

20 3H What personal protection should be used when oper-
ating welding equipment?

20.4 VEHICLE MAINTENANCE AND OPERATION

20.40 Types of Vehicles

Many types of vehicles are used in the waterworks
industry. However, the plant operator may only come into
contact with a few. Cars, pickup tiucks, forklifts, dump
trucks and some electrically driven cars are the types of
vehicles " ^ operator is most likely to be involved with and
need to n.. .<tain. In addition to motor vehicle safety, this
section will also consider the storage of fuel for these and
other engines in the plant.

20.41 Maintenance

To have a safe motor vehicle, there must be a preventive
maintenance program. Figure 20.9 gives a checklist for
finding potential safety problems and a means of recording
the preventive maintenance.

Tire inflation is a good example of proper safety checks
Not only is it unsafe to operate on under inflated tires, but it
also causes undue wear on the tire. Therefore, tires should
be checked regularly for wear, which ,Tiay be caused by
misalignment or low inflation. If tires are badly worn, they
should be replaced. '^Iways maintain the recommended
pressure in the tirb^. when checking, set the hand brake and
turn off the motor.

Next, when changing tires, be sure the jack you are using
has sure footing Position the jack at nght angles to the
direction of the lift Jacko are a problem m general, and you
should make sure that proper jacks are in each vehicle. In
other words, select the proper jack for each job and choose
only one that is safe and strong enough. If blocking is
required, only use safe supports, avo:d leaning the jack and
protect hands Always stay a safe distance from the jack
handle as many injunes are caused by flying jack handles.
Also, injunes are caused by overloading jacks. In addition,
where needed, use braces or other supports to prevent
tipping the vehicle over, another cause of serious injuries.

Fueling motor vehicles also involves some hazards. V-
ways stop the vehicle's engine. Remember to remove the
fuel hose immediately after using it. You could start a fire if
you carelessly drive off with the hose still attached. Also,
rake sure the cap is replaced tightly on the tank. Do not
permit smoking m the vicinity of gas delivery pumps at
anytime. Avoid any sparks, and skin contact. Use only high-
flash point solvent for cleaning up any gasoline. Some other
safety tips when refueling are: do not let the tank overflow,
always set the brake, hang nozzle up properly onto the
pump and eliminate any leaks on the hose connections.

Most small w'**'^" *'C3tment plants do rot have hoists or
pits for vehicle luDrication. However, mosi of the following
suggestions are applicable. First, keep all walkways, steps,
tools and containers free from grease, oil and other dirt. This
will reduce the possibility of accidents caused by these
items. As when maintaining any equipment, use the right
tools, keep shoes free of all oil or grease and use only non-
slip soles on the shoes.

If the plant is equipped with a hoist, do not permit anyone
to remain inside the vehicle when 't is on the hoist. When
lifting the vehicle, do not permit tools on the hoist or vehicle
that may fall onto you or other personnel in the work area.
Keep the driveway free of hoses, tools, and cars and always
keep you hand on the operating level when raising or
lowering the vehicle.

Most water treatment plants have assigned specific areas
for washing or steam cleaning vehicles. If your plant does
not have such an area, you should have one assigned. This
area does not have to be elaborate, but should have water
hoses and steam cleaning equipment and be adequately
drained. The same safety rules apply to makeshift installa-
tions as apply to completely equipped cleaning areas. The
most important consideration is the steam cleaner. Keep the
nozzle clean, check water level on coils before turning on
the flame, and always wear protection for your eyes and
face Make sure that the cleaner is adequately ground and
be careful of cleanin'^ compounds (see Caustic Section for
burns). Maintain steam hoses, check connections and never
permit horseplay with steam cleaning equipment. As in other
work areas, keep the wash rack free ^''om grease and oil and
oily rags. Hoses should be stored on the rack when not in
use. always use scaffolding or platforms when cleaning the
tops of vehicles.

20.42 Seat Belts

Many water treatment plant operators have some reason
for not wearing seat belts. The reasons may sound good,
but they won't protect you in the event of an accident. Many
lives would have been saved if seat belts were used. The
water utility should equip all vehicles with seat belts and
require evj?'/ operator to use them.

424 Water Treatment

GiECK

1st

2nd

3rd

4 th

5th

Oil

Water

Tires

}tom

Headli^ts, High - Low

Tail Lights

Turn Signals

Stop Lights

Battery v;ater

Fire Extinguisher

First Aid Kits

Windshield 'vJipars I

Visual Inspection - Wire Rope

- Hook

tl II

- Sheaves

~ Boom

- Hydraulic Ijovel

Operational Test Controls

SERVICE I^LEAGE READINGS

FUEL CavJSUMPTION

Week

Present

Last Service

Difference

Start Mileage

1st

End Mileaqe

2nd

Total Miles

3rd

Fuel Used

4th

MPG Averaqe

5th

Fijg. 20,9 Mobile Equipment Check List

Safety 425

20.43 Accident Prevention

The best overall means of preventing vehicle accidents is
defensive dnving. This method requires training and a
certain mental outlook on the part of the vehicle operator.
Most, if not all, drivers think they are good at what they do
and this may be true to some extent. However, if each driver
would operate all vehicles as if all other drivers were the
world's worst drivers, accidents would be greatly reduced

Good drivers check out their vehicles each time they use
them and have any maintenance performed when needed.
They use proper signals for directional change, always
observe traffic regulations and show courtesy to others.
Remember that drivers in an agency vehicle represent the
agency. Therefore, good driving skills are good for public
relations.

Another way to avoid accidents is.

This IS a very unwise practice which is dangerous to the
vehicle and hazardous to its operator. A good rule to use
when following another vehicle is the old one-car-length for
every 10 MPH, and if there is limited visibility, increase that
distance. Another rule is the "Ihree Second Rule" which
says you must be at least three seconds behind the car in
front of you. Take precautions when backing up. Always set
the bi'ake and/or shift to "Park" when parking the vehicle. Be
cautious at intersections. As a defensive driver, always be
ready to give the right of way. No right of way Is worth
injuring oneself.

In some cases, even the most defensive and careful driver
Has an accident. Because of this, each vehicle should carry
tiashlights, flares, flags and a fire extinguisher, along with a
first aid kit. In the event, of an accident, the driver should
know how to fill out all the forms, a supply of which should
be provided in the vehicle.

Remember, when operating a vehicle, an accident can be
prevented by defensive driving. The plant operator should
have each member of the staff take a defensive driver
training course. Each driver should develop a defensive
driver frame of mind. Developing a good attitude and driving
skills are the key to accident prevention when operating a
vehicle. In any event, new employees should be given road
tests in operating the types of vehicles they v/ill be using.

Here are a few reminders when operating a vehicle.
During a storm, roadways or pavement are likely to be

slippery. Slow down, pump the brakes when stopping and
remember the minimum distance rules. No driver should be
required to operate an unsafe vehue. Keep copies of a
suitable form for reporting mechanical problems in each
vehicle and encourage operators to use them.

20,44 Forklifts

Most water treatment plants and pumping stations have a
forklift. Most, if not all, p»ant operators use this vehicle to
move chemicals, repair parts, and even use it when making
repairs to lift heavy objects. Therefore, every plant operator
should be trained in the use of the forklift.

Following are a few points regarding safe operation of the
forklift with suggestions for operator safety as well as
protection of others who may be in the operating area of the
forklift. Keep all aisles free of boxes and other debris. Do not
permit anyone to nde on the forklift except the operator.
Never overload the forklift. Always be sure the warning
signals are operational and never leave the power on when
leaving the forklift. Like other vehicles, check out the brakes
before operating. Be careful at intersections of aisles and
always face the direction of travel. If a loaded forklift is to be
placed on an elevator, be sure that the load on the forklift
and the weight of the vehicle do not exceed the lifting weight
of the elevator. Also, make sure the forklift load is stacked
properly before lifting or moving. When handling drums,
special lifting and retaining devices are needed.

Figure 20.10 is a typical forklift inspection form.

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 440.

20,4A What cause^ tire wear on motor vehicles?

20 4B Motor vehicles should contain what safety devices?

ERIC

4iS

426 Water Treatment

SOUTHERN NEVADA WATER SYSTEM
For Truck Operator Inspection

Operator

Brake

Boom

Tilt

Back

Horn

Wheel

Rprnarkc

un.

r*
r

FORM ^/268 — S.N.W.S.

ERIC

Fig, 20, 10 Forklift inspection form

447

Safety 427

DISCUSSION AND REVIEW QUESTIONS

Chapter 20. SAFETY

Lesson 3 of 4 Lessons)

Write the answers to these questions m your notebook
before continuing The problem nuTl-yering continues from
Lesson 2.

21 How can an operator prevent fires in a water treatment
plant?

22. How would you maintain water-type fire extinguishers'?

23. How would you maintain fire hoses in your water
treatment plant?

24 What precautions should be taken in areas where
flammable material is stored?

25 How can an operator make visuors feel as if the water
being produced is safe to drink?

26 How would you remove a manhole cover?

27. What precautions should be taken when operating
power tools in a wet or damp location?

28. What fire hazards should be considered before doing
any welding?

29. How would you safely refuel a motor vehicle?

30 What safety precautions should be taken when driving
during a storm?

ERIC

428 Water Treatment

CHAPTER 20.

(Lesson 4 of 4

20.5 ELECTRICAL EQUIPMENT

20*50 Eiectrtcal Safety

As a water plant operator, you aie not expected to be an
expert in electrical equipment, but you nrijst have a working
understanding of electricity. This includes an understanding
of the safety precautions needed to operate the electrical
equipment. After all, electrical energy is required to power
most of the treatment plant operations. The objective of this
section is to show you how to operate safely and to become
involved to a limited degree in the maintenance of electrical
equipment. Elecfxity is unforgiving to the careless treat-
ment plant operator.

20.51 Current — Voltage

Many types of electrical current are used in water treat-
ment plants and the associated pumping plant. Each day the
plant operator is exposed to this equipment, giving little
thought to the potential hazards ;f the equipment. Current
may come into the plant at a high voltage, for example, 69
KVA, reduced to 4160 volts or 2300 volts. This current may
power pump motors, blowers and other equipm.ent at lower
voltages of 440, 220, or 120 volts and within starters may be
reduced to 24 or 12 volts or changed over into DC voltages.
Given all of these variou*" voltages, the operator mu't be
careful not to become careiess working with equipment.
Therefore, become familiar with the types of current and
voltage in the plant. By knowing this, you will avoid the
mistake of becoming involved with unsafe electrical currents
or practices for which you are not trained. This will also
enable you to know when to ask for a qualified person to
perform any necessary repairs.

20.52 Transformers

Electrical power entering a plant is routed through trans-
fomfiers to reduce the voltage in most cases. There are
many types of transformers although the operator may only
think of the larger ones that bring the power into the plant.
Sometimes these are owned by the waterworks and there-
fore the maintenance is the responsibility of the operator.
There are few, if any, plant operators who are qualified to
perform such maintenance. Never attempt to wcrk on a high
voltage transformer without the ass itance of qualified per-
sonnel. Such personnel can be located at tlie power com-
pany or contact an electrical contractor who specializes in
the repair and maintenance of electrical transformers. You
will, however need to keep records of the transformer's
operation. This information is helpful to repair personnel and
is useful to operators who need to know the status of the
transformer.

There are many small transformei's within the plant's
operating gear and it is these you may have to maintain.
Most often these low-voitage transformers become over-
worked; they overheat and burn out. Any fire in the electrical
gear can be hazardous. Be very careful when opening a
starter, breaker box or indicating instrumentation if a fire or
overheated transformer is suspected. Operators have been
badly burned by not thinking before opening such 'devices
when they smell smoke in pumping stations or treatment
plants. When solving problems with hot, overheated, or
buming transformers, remember what you learned in Sec-

SAFETY

Lessons)

tion 20.2 about electrical fires. For the safety of operating
personnel and the safety of the plant, regularly inspect or
have someone inspect both large and small transformers. If
you detect any overheating, have a qualified electrician
inspect ano replace any transformer that is not functioning
properly.

There should be a fence around the transformer station,
with a locked gate and only a limited number of keys issued
to plant personnel. The operator may perform routine pre-
ventive maintenance such as removing weeds, brush and
general cleanup. Replacing fuses and major maintenance or
repairs should be made by the power company or qualified
electricians. Maintenance must be performed by qualified
and well trained personnel.

20.53 Electrical Starters

As a treatment plant operator, your most frequent contact
with electrical power will probably be with electncal starters
on the motor control panels. These devices are used
throughout the plant and provide an interface between the
operator and the flow of energy. The starter may be located
on a switch panel or there may be a switch that is remotely
located from the starter. One of the first safety procedures
you should take is to use a special insulated mat on the floor
at all switchboards. The starter should be provided with
adequate lighting and clearly marked Start-Stop buttons.
Replace indicating, lights as needed without delay. There
should always be clear and adequate working space around
the starter or sxyitch panels. To reduce the hazards of fire in
electrical starters, they should be cleaned and maintained on
a regular basis. Such maintenance must be performed by
trained, qualified personnel. In electrical starting equipment,
fires can easily occur because of accumulation of dust and
dirt on the contactors, or when they become so badly burned
that they do not make proper contact; thus, they become
overheated and start fires. The key to preventing fires in
starting equipment is a good preventive maintenance pro-
gram.

20.54 Electrical Motors

The treatment plant operator is exposed to many types
and sizes of electrical motors. In some plants, the motors
are old and require more attention because of exposed
parts. The newer electncal motors are enclosed and have all
parts protected. For the old motors, you should install
guards or guard rails to prevent accidental contact with live
parts of the motors.

449

Safety 429

Some of the electric motors may have exposed couplings,
pulleys, gears -^r sprockets that also require consideration
For these and other moving devices, a wire cloth gear guard
may be installed The gear guard can also be made of sheet
metal However, no matter which type of guard is used, it
must be securely fastened onto the floor or some other solid
support The safeguards must be constructed and fitted to
prevent material being handled by operators from coming
into contact with the moving parts driven by the motors.

Another consideration is projections on couplinos, pulley
shafts and other revolving parts on the motor or on the
device being driven These projections can be bolts, keys,
set screws or other projections The projections should be
removed, reduced or protected by one of the above guards.

Check grounding on ait electncai n.otors as part of a
routine maintenance program. The motor frames them-
selves must be grounded if the wires to the motor are not
enclosed in an armored conduit or other metallic raceway.
Check that all jointb are mechanically secure to assure good
grounding. In the case of portable electric motors, the
simplest way of grounding is an extra conductor m the cord
serving the motor. The best way is to install a ground fault
interrupter (G F.I.) receptacle. This device will automatically
disconnect the tool from the power supply if the ground is
not connected and will supply the greatest protection to the
operator and to the equipment.

When using portable electrical motors always check the
service cord. If the cord or receptacles are in poor condition
or showing signs of wear, they should be replaced. A badly
worn cord must never be used in a wet location.

20*55 instrumentation

In this area of water treatment the operator is not exposed
to a great deal of hazard, but must give some consideration
to these devices since they are operated by electncai
current. This is also true of all other automatic equipment.
Although most instruments protect the operator, there is still
a degree of hazard when changing charts, calibrating or
performing other maintenance. First, when calibrating an
instrument, you are exposed to at least 12 Volts DC to 120
Volts AC If you become grounded with the 120 Volts AC,
you may be killed or severely injured. Also, when maintaining
automatic control equipment, adjustment of one instrument
may start another device, exposing another operator to a
hazard because of an unexpected start. As mentioned
above, electronic devices operate on low current, but don't
forget that there is still high voltage located somewhere in
the instrument.

20.56 Control Panels

Control panels and switchboards should only be accessi-
ble to qualified personnel. The plant operator should have a
standard operating procedure (SOP) for lockout of all electri-
cal equipment (Figure 20.11). Two hazards due to the lack of
a good lockout procedure are (1) accidentally starting a
piece of equipment exposing a fellow operator to a hazard,
and (2) turning electrical power on when someone is still
working on the equipment, exposing that person to danger.

Always provide adequate working space in and around
control panels. As with electrical motors, the panels must be
well grounded. At some locations there may be a need for
special insulating mats, such as in wet locations. Adequate
lighting must be available inside the control panel as well as

outside for those who do the maintenance Moisture or
corrosive gases must be kept away f'-om the control panels.
To reduce fire hazard, never store any hazardous matena^
next to switchboards or control panels. Panels carrying
greater than 600 volts musr be permanently marked warning
of the hazards Areas of high voltage should be screened off
and locked with a limited number of keys given to authorized
personnel only

In a safe lockout procedure, the switches are locked open
and are properly tagged, only the operator who is doing the
maintenance should have a key. In fact, all people who
perform electrical m .intenance should have their own indi-
vidual lock and key so as to maintain control over the
equipment being worked on by each individual

QUESTIONS

Write your answers in a notebook and then compare your
answers with those on page 440.

20 5A Why should each plant operator become familiar with
the type of current and voltage in the water treatnrient
planf?

20 5B List the moving parts on electrical motors that re-
quire safety guards

20 5C What are two hazards created by the lack of a good
lockout procedure for control panels and switch-
boards''

20.6 LABORATORY SAFETY^

20.60 Laboratory Hazards

In general, water plant operators do not experience a
great deal of exposure to hazardous laboratory conditions.
However, you will be in contaci with glassware, toxic chemi-
cals, flammable chemicals, corrosive acids and alkalies.
There may be times when you will be exposed to hazardous
bacteriological agents. The seriousness of the hazards
depends mainly upon the size of the plant and the operating
procedures in the treatment piant. For your own safety, learn
the proper procedures for handling laboratory equipment
and chemicals.

20.61 Glassware

An important item in laboratory safety is handling of
glassware Almost all tests performed by an operator will
require the use of some glassware. The operator's hands, of
course, are exposed u the greatest hazard. To reduce
accidentc when handling glassware, never used chipped,
cracked or .uoken glassware in any testing procedures. All
such glassware should be disposed of in a container marked
"For Broken Glass Only " Never put broken glass m waste-
baskets Although it may not be a hazard to the operator, it is
a danger to those who clean out the wastebaskets. Clean up
any broken glass and/or spilled chemicals to reduce haz-
ards to others. Never let broken pieces of glass remain in the
sink or in sink drains. This may cause cuts to others who
unknowingly try to clean the sink.

Washing glassware is always potentially hazardous. The
glassware can be broken while being washed, causing cuts,
or cuts can be caused by chipped or cracked glassware.
Also, the cleaning compounds themselves can be a problem.
Sometimes strong acid cleaners are used to remove stains

6 See FISHER SAFETY MANUAL Fisher Scientific Company, 711 Forbes Avenue, Pittsburgh, PA 15210.

Er|c Utl^ 450

430 Water Treatment

SOUTHERN NEVADA WATER SYSTEM
Standard Operating T/ocedure

TITLE: SAFETY, EQUIPMENT LOCKOUT

Number: 122

SECTION: SAFETY

Prepared By:
RLC-2/1/73

OBJECTIVE

The purpose of this procedure is to provide the highest degree of safety to SNWS employees, also to prevent
mechanical damage or undesirable operation of equipment when it is being serviced or repaired.

PROCEDURE

Locks for securing equipment shall be issued to maintenance people and will be available to other personnel
at the superintendent's office. There is some machinery that is designed and equipped with facilities for minor
rep? " adjustments and lubrication while in opere.J;on. However, in all cases, the equipment must be turned
off • such repairs or lubrication.

In order to prevent accidental starting or endangering the safety of operating or maintenance personnel, be-
fore performing any woik the equipment must be secured. In the event the starter, motor or electrical service
to the equipment cannot be locked out, a "Do Not Operate" safety tag must be attached to the starting mecha-
nism.

During inspection, if an operator finds that the continual operation of a unit may cause damage, il should also
be shut down and locked out. The key to the lockout device should be attached to the Work Crder. Thereafter,
no one other than the Manager, Maintenance Superintendent cr Treatment Superintendent or someone
directly ordered by the above is to remove the lockout device.

Fig. 20, 1 1 Standard operating procedure for locking
out of electrical equipment

ER?C 451

Safety 431

from the glassware. Without protective gloves, you hands
could be seiicusly burned by these acids.

20.62 Chemicals

When handling liquid chemicals such as acids and bases,
always use safety glasses or face shields. If working with
ether or hloroform, avoid inhalation of fumes and always do
this type of work under the ventilation hooa. Be sure to turn
the ventilation fan on. Of course, be careful of open flames
when using flammables such as ether. As d general rule, do
not permit smoking in the laboratory. All chemicals should
be stored in proper locations; do not set chemicals on the
laboratory benches where they may cause an accident if
spilled or if the container is broken.

When handling laboratory gases, give consideration to
their location and potential accident hazards. Gas cylinders
must be prevented from falling by using safety retaining
devices such as chains. The valve and cylinder regulator
should be protected from being struck by stools, ladders
and other objects.

When mixing acid with water, always pour tl^e acid into the
water while stirring.

Nev^ add wd^vto add \xcaM^a

tkc^(y'i^^t\\i^ catMbiHq splattering
awd esce^ heat ^cnevs^iow.

Always use safety goggles, yloves and protective garments.
When cleaning up acid or alkali spills, dilute with lots of
water even if you flush them down the sink drain. Baking
soda can ^e used to neutralize acids, and vinegar is used to
neutralize bases. Never allow mercury, gasoline, oil or
organic compounds into the laboratory drains. Use only a
toxic waste disposal dram system for these items. Pouring
such compounds down sink drains can cause an explosion,
allow toxic gases and vapors to ente. the lab, or destroy the
piping.

You must never use your mouth with the pipet for transfer-
ring toxic chemicals, acids or alkalis. Use a suction bulb,
aspirator, pump or vacuum line. If you use your mouth, there
is always the danger of getting tho toxic solutions into your
mouth.

ERJC .^1^

20.63 Biological Considerations

Do not take chances with bacteria. A good policy is to
have each operator immunized vvith anti-typhoid vaccine and
to keep their booster shots current. Always use good
sanitary practices, particularly when working with unknown
bacteria or known pathogens. Never pipet bacteriological
samples by mouth. ALWAYS USE A PIPET BULB.

When exposed to any bacteria, you should make it a habit
to always wash your hands before eating or smoking. If you
have any cuts or broken skin areas, these wounds should
not come in contact with bacterial agents. You should wear
protective gloves or cover the wound with a bandage when
working with any kind of bacteria.

All work areas should be swabbed down with a good
bacteriological disinfectant before and after preparing sam-
ples. As a gene il policy, the preparation or serving of food
should never be permitted in the laboratory. Also, give some
consideration to proper ventilation, because some bacteria
may be transmitted via the air system.

20.64 Radioactivity

There are many laboratory and treatment plant instru-
ments that use radioactive isotopes in laboratory tests and
research. A plant operator may be exposed to radioactive
compounds when calibrating sludge density meters or using
research isotopes. From a safety standpoint, only qualified
personnel should be involved in the use of radiorDtive
compounds. If radioactive compounds are present in the
laboratory, warning signs should be posted. The disposal of
all radioactive compounds must be performed strictly by
qualified laboratory personnel in accordance with govern-
ment regulations.

20.65 Laboratory Equ'oment

20.650 Hotplates

You will probably use a hot plate m your >""'^<^hold odor
number (^ON) tests. YOo should turn the hot plate off when
not in use, never place bare hands on the hot plate to check
if It IS hot. Wh"in using the hot plate to remove gas or fumes,
always use the hood and turn on the hood ventilation fan.
Never place glassware onto a hot plate if the outside of the
glassware has water or moisture on the surface between the
glass and the hot plate. Steam will form at this interface and
cause the glass to break. When taking hot glassware off the
hot plate, always usj asbestos gloves.

20.651 Water Stills

Most water btills in the laboratory today are the electrical
type. To observe good safety practices, check the items
described in the electrical safety section of this chapter,

452

432 Water Treatment

such as good grounding. Set up a SOP (Standard Operating
Procedure) for proper operation of the still and follow the
manufacturer's Instructions for proper starting and stop-
ping. The sti.. will require cleaning from time to time. Be very
careful when disassembling the still. Parts may be frozen
together because of hardness in the water and may require
an acid wash to separate. Be sure that the boiler unit is full of
water before turning the still on. Never allow cold water into
a hot boiler unit because it may cause the unit to break.

20.652 Steriliz rs

There are two types of sterilizers: (1) dry electrical steriliz-
ers a Id (2) wet sterilizers (autoclaves). In the dry electrical
sterilizers, check the cords frequently because the high heat
may damage the wiring. Always let the unit cool off before
removing its contents. Wet sterilizers (autoclaves) are under
pressure by steam and should be opened very slowly. Use
asbestos gloves and protective clothing when unloading the
autoclave. Cover the steam exhaust with asbestos covering
to prevent burns. Any leakage around the donr should be
repaired by replacing door gaskets, or even the door if It is
worn or bent Always load the autoclave In accordance with
the manufacturer's recommendations. Never allow an oper-
ator to work with this equipment without proper Instruction
in its operation.

20.653 Pipet Washers

Cleaning p«pets can be hazardous. Many laboratories
have P oipet cleaner which contains an acid compound or
other Cleaning agents. Always use protective clothing and a
face shield when working with the washer jnit. Try to avoid
dripping or spilling the cleaninq compound when transfer-
ring the pipets. if the acid cor o into contact with your skin,
use the remedies recommer.jed in Section 20.11, "Acids."

QUESTIONS

Write your diibvvers in a notebook and then compare your
answers with those on page 440.

20.6A Why -s washing glassware always a potential haz-
ard?

20 6B Whr p.. .dons should be taken when handling
liquid chemicals such as acids and bases?

20.6C Why c'lould mercury, gasoline, oil or organic com-
pounds never be allowed into laboratory drains?

20.6D How can an operator be exposed to raoioacttve
compounds?

20.6E Why should cold water never be allowed into the hot
boiler unit of a water still?

20.7 OPERATOR PROTECTION

20.70 Operator Safety

So far In this chapter we have discussed many means by
which you can protect yourself and your equipme* t. In this
section we wish to discuss your own personal projection.
Take a look at the means of protecting the eye, the foot, the
head and most of all — look at wator safety. After all, a plant
operator is always In contact with water. The water may be
found in raw water reservoirs, settling basins, clear wells or
filters. Operators have lost their lives by falling into the
backwash gullet. Operators have lost their lives in the
finished water reservoirs. As unlikely as it seems, fatal
accidents have happened in the past and will happen again
in the future. Therefore, it is the responsibility of each

ERIC iH^^^

operator to watch for any safety problems in the plant's
reservoirs, pumping stations, or filters You, the operator,
are responsible for yourself. You should never expose
yourself to unsafe conditions.

A major problem confronting many operators is where ar
how can reliable safety vendors and equipment be locate
State, regional and national professional meetings, such as
those spor.sored by the American Water Works Association,
often have displays or exhibits featuring manufacturers of
safety equipment. This is an excellent opportunity to meet
the representative of these companies and discuss with
them what equipment they would recommend for your
situation. Also other operators who have had experience
with safety equipment of interest to you often attend these
meetings and are anxious to share their experiences with
you.

If you are unable to attend these meetings, the program
announcements will often have a short description of the
types of safety equipment that will be featured by each
vendor exhibiting at the conference You can obtain the
vendor's address by looking in professional journals, buy-
ers' guides or by writing to the sponsor of the conference.

20.71 Respiratory Protection

There are many respiratory hazards in and around the
treatment plant that an operator is exposed to daily including
chemical dusts, chemical fumes, and chemical gases such
as chlorine, ammonia, sulfur dioxide, and acid fumes, to
name on'y a few. Whenever working around or handling
these and other compounds, you must take adequate pre-
cautions.

Two types of conditions for which you should be prepared
are: (1) oxygen deficient atmosphere, and (2) sufficient
oxygen, but a contaminated atmosphere containing toxic
gases or explosive conditions. In either circumstance you
wi!! need an independent oxygen supply. However, an
independent oxygen supply will not protect you from an
explosion.

Call your local gas company and ask their experts to enter
the explosive area, if entry is essential. Your independent
oxygen supply should be of the positive-pressure type to
protect you if there are any leaks. Good ventilation can
reduce explosive conditions.

20.72 Safety Equipment

All waterworks safety equipment such as life lines, life
buoys, fire extinguishers, fencing, guards, and respiratory
apparatus must be kept in good repair This and other safety
equipment is necessary to protect operators or visitors from
injury or death. Safety equipment may fall into disrepair
because it Is only used occasionally and may detenorate due
to heat, time and other environmental factors. First aid
equipment should also be provided and kept resupplled as it
IS used. The operating staff should be given regular instruc-
tions in the use and maintenance of the safety equipment.

Provide protective clothing for all operators handling
chenlcals or dangerous matenals. Keep the clothing clean
and store it in a protective environment when not In use.

The water utility is responsible for providing outward
opening doors, remote-controlled ventilation, inspection

453

Safety 433

windows and similar safety devices where appropriate. This
equipment should be exercised, kept clean and well main-
tained so that it will operate when needed.

Respiratory (self-contained breathing) apparatus must be
stored in unlocked cabinets outside of chlorination, sulfur
dioxide, c?rbon dioxide, ozone and ammonia rooms. The
storage cabinets must have a controlled environment to
prevent deterioration of the equipment.

The operator has the responsibility to inspect each appa-
ratus for deterioration and need for repair. Safety equipment
is of no use to the operator if it fails when put to use, and
may cost you your life if it is in poor condition. Some self-
contained breathing apparatus (air packs) depend on com-
pressed air to supply the oxygen. Under conditions of
deficient oxygen supply, the canister type of respirator is
useless. You could lose your life by entering a room contain-
iny chlonne gas (which is heavier than air) while depending
on a poorly maintained respirator. Although you might have
protection from the chlorine, you would not have adequate
oxygen. Nevb take a chance with a toxic gas. In water
treatment plants, use only the positive-pressure type of self-
breathing apparatus.

Many newer plants are bfting constructed with indepen-
dent air supplies consisting of a helmet, hose and com-
pressed air. The helmet is connected by a hose to an
uncontaminated air source. The key word here is "unconta-
minated." Not only should the operator follow a maintenance
program for the hose and mouth pieces of the apparatus,
but the operator must maintain the air supply. The air is
supplied by mechanical equipment which requires mainte-
nance. The air pressure is controlled by a reduce^ or
regulator which must be kept clean anc maintained to be
available when needed. Set up a preventive maintenance
program for this equipment. It should be checked out on a
weekly basis, and records should be kept of each inspec-
tion. The record should show conditions of the hoses,
regulators, air filters, compressors, helmet and any other
apparatus furnished with the system.

The old standby, of course, has been the air packs or seif-
breathing apparatus. These units are carried by the user,
giving the operator an independent source of air (oxygen).
The unit can be used in any concentration of contamination
of gases, duot or anywhere the aimosphere is oxygen
deficient. There are two types of units. One type of unit
depends on compressed air or oxygen, and the second
system generates oxygen by use of chemicals in a canister.
The oxygen is generated by the moisture exhaled by the
user. Because this equipment is not used daily in the water
treatment plant, there must be a preventive maintenance
program, with records, inspection and operator check out.
As with any system, self-breathing equipment requires main-
tenance. This is vital because the op ator's life will depend
on how well th's apparatus performs.

Training is another important consideration. Even though
you may have used the breathing apparatus many times in
the past, you should be checked out each month on the
equipment. There should be a maximum allowable time for
putting on the apparatus. The apparatus should be checked
out under field conditions, such as using amtnonia or some
other non-toxic gas. Remember, it is too late to learn how
fast an operator can put on a self-breathing apparatus when
a room is filled with chlorine.

Be aware that there have been cases where operators
have been saved t)ecauso they knew how to use the
breathing apparatus properly. Only repeuted practice will
enable you to master this survival skill.

ERJC ..[.

20.73 Eye Protection

The water treatment plant operator has only two eyes.
You may think that everyone is aware of this fact. However,
some operators behave as though they have many eyes and
are very careless about protecting them from hazards.

Because some operators fail to see the value of eye
protection, it will take a maximum effort on behalf of the
supervisory staff to enforce an adequate eye protection
program. There must be an intense program of education,
persuasion, and appeal to guarantee compliance with an
eye protection program.

Most conditions in which a plant operator needs eye
protection are not too difficult to understand. Eye protection
IS needed when handling msny of thf? liquid chemicals, acids
and caustics. Some of the tests per ormed in the laboratory
require eye protection. Only a few moments are required to
put on a ^.^^e shield or safety glasses, and remember — the
loss of ai^ eye will last a lifetime.

QUESTIONS

Wnte your answers in a notebook and then compare your
answers with those on page 440.

20.7A When entering an oxygen-deficient atmosphere,
what type of oxygen supply is recommended*^

20.7B Where should respiratory apparatus be stored?

20.7C How frequently should independent air supply equip-
ment be checked out and what should be inspected?

20 7D How can compliance with an eye protection program
be encouraged?

20.7E Under what conditions does an operator need eye
proteotion*?

20.74 Foot Protection

There are few situations under which a water treatment
plant operator needs foot protection. In the normal routine of
daily operation of the plant, there are not many hazards to
the operator's feet. But in some plants the operator also
performs plant maintenance. Here the steel toed safety
shoes are useful. The shoe should bo able to resist at least a
3C0-pount^ (136 kg) impact. An important consideration in
any plant ^nder operating conditions is the use of rubber
boots. Th i rubber boots are needed when handling acid or
caustic, or when the operator is working in wet conditions
such as reservoirs, filters or chemical tanks. Under these
circumstances, the agency should have an adequate supply
of boots in various sizes. If these conditions are something
that the operator is exposed to daily or weekly, the agency
should give the operator a pair of boots for personal use.

454

434 Safety

20.75 Hand Protection

The treatment plant operator's hands are always exposed
to hazards. These include not only minor scratches or cuts,
but also exposure to chemicals that may not attack immedi-
ately. Some compounds, such as alum, attack the skin
slowly. Because there is no immediate pain, you may think
there is no damage. This is not true; the attack on the skin is
slow and may cause an infection at a later date. Therefore,
when handling chemicals, always use rubber gloves. As part
of a safety package, each operator should be issued a pair
of rubber gloves and also a pair of leather gloves. These
gloves should be replaced when they no longer provide the
necessary protection.

There are other compounds such as solvents th&i will
absorb through the skin and can cause long-term effects.
For such special problems, there is a need for neoprene
gloves. Another problem is that of handling hot materials,
such as laboratory flasks and beakers. Here you may need
asbestos fabnc gloves. When wc ng around machinery
that IS revolving, wea.ing gloves or other hand protection
can be dangerous. If a glove gets caught in the machinery,
you could become injured. Don't let your protective equip-
ment itself become a hazard.

Be sure that t^^e gloves you are wearing are the right type
for the job you are doing. The gloves should allow for quick
removal and be in good condition. Always check for cracks
and holes, flexibility and gnp. Keep them clean and in good
condition. Theie are many types of gloves and the proper
type should be wom for each job.

1. CLOTH GLOVES protect from general wear., dirt, chaf-
ing, abrasions, wood slivers and low heat.

2. LEATHER GLOVES protect from sparks, chips, rough
material and moderate heat.

3. RUBBER GLOVES protect against acids and some
chemical burns.

4. NEOPRENE AND CORK-DIPPED GLOVES give better
grip on slippery or oii/ jobs.

5. ASBESTOS OR ALUMINIZED GLOVES are heat-resist-
ant to protect against sparks, flames and heat.

6. METAL MESH GLOVES protect from cuts, rough mate-
rials and blows from edge tools.

7. PLASTIC GLOVES protect from chemicals and corro-
sive substances.

8. INVISIBLE GLOVES (barrier creme) protect fronr. exces-
sive water contact and from substances which dissolve
in skin oil.

20.76 Head Protection

In most areas of a water treatment plant, there is really no
need for a hard hat. However, there are certain hazardous
conditions under which the operators should be required to
wear a metal, plastic-impregnated fabric, or fiberglass hat.
The hard hat should have a suspended crown with an
adjustable head band; provide good ventilation; and be
water resistant. Operators should be required to wear the
hard hats when work is being performed overhead, or in any
location where .here is danger of tools or other materials
falling, for example, working in filters, settling basins or
trenches. There has been a long history showing the value
of hard hats in reducing injuries and death.

20 J7 Water Safety

Every operator in a treatment plant is exposed to situa-
tions in which the operator's life can be lost due, either
directly or indirectly, to water. Although dunng you. daily
activity you may never think in terms of drowning, this
hazard is always present in the treatment plant. If you are
working at a reservoir or a lake in a boat, you may think of
water safety, but still never pay real attention to the danger.

Starting at the treatment plant, you can take simple
measures that will reduce hazards. To reduce the hazard of
slipping when working around clarifiers or settling basins,
use non-skid surfaces on ladders and walkways going into
and out of clanfiers or sedimentation basins. Be very cau-
tious during cold or wet weather. Water freezes into ice
which is slippery.

Keep all handrails or other guards m good repair; replace
any that become unsafe. Many older plants do not have
protective handrails; install rails or chain off the unsafe area
to a.i employees and mark off with warning signs. The
unsafe areas can be guarded with %-inch (9 mm) manila
rope, chains or cables thai you may have around the plant.

Filters are an important area of safety consideration
because there is always activity in or around each filter, such
as washing or maintenance. Here you should make repairs
to handrails immediately when needed. Station emergency
gear around the filter areas; equipment such as life jackets
are good, but buoys, Ve-inch (9 mm) manila line or a long
wooden pole are much more useful. These types of devices
can be used to rescue someone who has fallen into the filter.
An operator should never work m the filte when it is being
backwashed. There is always the danger of falling into the
washwater gullet and being unable to get out before drown-
ing.

Sedimentation basins, flocculation basins or clarifiers
present many of the same problems as filters. Maintain
handrails, place warning signs or put up guard ropes or
chains. Also keep life nngs and manila or nylon lines in good
repair. A lift ring, life pole and lines should be stationed at
each basin. A good idea Is to shelter the safety gear from the
weather, but do not cause the gear to become Inaccessible.

In reservoir operation and maintenance you will encounter
two types of water: (1) raw water and (2) treated water. In a
raw water reservoir or lake, you have to worry only about
personnel safety. In a treated water rebsr /oir, you must also
be concerned about the safety of the v.'ater going to the
customer. If you are working out oi a boat, make sure that
everyone in the boat is wearing a life jacket. Also take on
board both a safety line and buoys. Cold weather conditions
are an added problem. Even though you may be a good or
excellent swimmer, the thermal shock of cold water may
quickly paralyze you, making you unable to save yourself.
Under such conditions, if a second operator goes into the
water to save you, there may be two lives lost.

455

Water Treatment 435

Of course, vjhen taking a boat out on the water it should
first be checked out for safety. Check the bilge pump,
ventilation in the compartments, the safety cushions, fire
extinguishers, battery and the engine. Also check for safety
equipment, life jackets, lights, mooring lines and fuel. If ) m
are applying copper sulfate powder or solution, other safeiy
equipment will be needed, such as respiratory and eye
protection equipment. Prepare a de* iled equipment check-
list to use each time the boat goe.. out onto the lake or
reservoir. The boat should never be taken out on choppy
waters or when the wind is high.

On some occasions, there is a need for underwater
examination of valves, intake or other underwater equip-
ment or apparatus. Such work should only be performed by
employees who are trained in underwater diving. If there are
no qualified divers on your staff, you should hire such
personnel to do the diving and underwater inspections.
There are organizations with people who do this type of
work and they are well qualified in underwater examinations.
If an operator on staff is to do the diving, the operator should
be certified by a local diving school or other certifying
agency. The operator's certificate should always be kept
current and the operator should be required to perform the
number of dives necessary to keep this certification current.

In closing, all plant operators should know how to swim. If
they do ne», they should take a Red Cross class and learn
the minimum fundamentals to save their own lives. Any
operator working over open water should be required to
wear a buoyant vest. All basins should have approved safety
vests, buoys and life lines stationed at outside edges.

QUESTIONS

Write your answers in a notebook and then compare your
answers .vitn those on page 440.

20.7F Under what operating conditions should an operator
wear rubber boots?

2C.7G Under what specific conditions should an operator
be very careful wearing gloves?

20.7H Why should operators never work in a filter when it is
being backwashed?

20,71 W^^'"* Items should be checked before an operator
takes a boat out in the water?

20,8 PREPARATION FOR EMERGENCIES^

Emergencies are very difficult to plan and prepare for
because you never know what will happen and when it will
occur. Catastrophic events could include floods, tornados,
hurricanes, fjres and earthquakes. Serious injunes to any-
one on the plant grounds is an emergency.

Conduct penodic tours of your facilities with the local fire,
police and emergency response organizations to familianze
them with the site, potentially hazardous locations, and
location of fire hydrants will be very helpful if an emergency
ever occurs. Emphasize to these people that if a disaster
occurs, how important it is for your plant to be a top prionty
for assistance because the entire community relies on you
for Its dnnking water.

You should know the names and phone numbers of your
local and state civil preparedness coordinators.

If a chemical emergency occurs such as a chemical spill,
leak, fire, exposure, or accident, phone CHEMTREC, 800-
424-9300. CHEMTREC. (Chemical Transportation Emergen-
cy Center) provides immediate advice for those at the scene
of a chemical emergency, and then quickly and promptly
alerts experts from the manufacturers whose products are
involved for more detailed assistance and appropriate follow
up

Prepare a procedure for quick and efficient handling of all
accidents or injuries occurring in your treatment facilities
and your outside crews. All personnel must be familiar with
these procedures and must be prepared to carry them out
with a minimum amount of delay or confusion.

A copy of these procedures must be posted in all working
areas accessible to a phone and in all vehicles containing
work crews. Names, addresses and phone numbers of
operators in each working area should be listed in that area
and e.so those immediately available (day or night) by
telephone.

Everyone must study these procedures carefully and be
able to respond properly and quickly. Your health and life
may depend on these proceduies.

Table 20.7 is an example of a typical safety procedure and
Table 20.8 is a checklist of what must be done if someone is
seriously injured.

QUESTIONS

Write your answers in a notebook and then compare your
answers with tho5e on page 441.

20.8A What types of emergencies should operators be
prepared to handle?

20 8B Who should be contacted if a serious chc.iical
emergency occurs such as a chemical spill, leak, fire,
exposure or accident?

20.9 ARITHMETIC ASSIGNMENT

Turn to the Appendix at the back of this manual and read
Section A.36, "Safety." Work the example problems on your
electronic pocket calculator. You should be able to get the
same answers.

7 Some of the information in this section was provided by M Richard 9 Metcaif. Training Officer, County of Onondaga, New York

Er|c 456

TABLE 20.7 EMERGENCY SAFETY PROCEDURE

1 . DO NOT MOVE THE INJURED PERSON

except when conditions would cause additional injury,
such as a gas leak or a fire.

2. ADMINISTER ONLY SUCH AID AS NECESSARY TO
PRESERVE LIFE — TREAT FOR SHOCK

(a) clear throat and restore breathing

(b) stop bleeding

3. DO NOT ATTEMPT MEDICAL TREATMENT such as

(a) do not apply splints or attempt to set broken bones

(b) do not remove foreign objects from the body

4. NOTIFY YOUR SUPERVISOR

IF AN AMBULANCE IS REQUIRED:

1. CALL AMBULANCE — phone

2. Give this information carefu;*y and accurately:

(a) Location of the injured — be specific.

1. Street location and number. Town or City
"Remember some streets have north or south
or east or west designation — use the full street
name. Also, many streets in different towns
have the same name — specify the Town.

2. Location within the Plant area

(b) Phone number from whicn you are calling

(d) Post an operator to direct the ambulance to the
victim

3. Upon arrival of the ambulance:

(a) give name, address and phone number of the
irjured person to the ambulance crew

(b) notify relatives of injury and hospital to which
person is being taken

(Medical treatment cannot be given witnout the
permission of the injured or a relative, if a minor)

4. Call your supervisor

IF AN AMBULANCE IS NOT REQUIRED:

1. Take Injured: (see map) (Phone ,^

ask for Emergency Room)

Emergency Room
St. Joseph's Hospital
301 Prospect Avenu^

2. If possible, call ahead, ^ive the nances of injured and
nature of injury.

3. Notify relatives of injury and address of hospital

4. Call your supervisor

ERIC

TABLE 20.8 INJURED PERSON CHECKLIST

1. CALL AMBULANCE SERVICE, Phone

LOCATION OF INJURED

STREET

TOWN

BUILDING LOCATION
PHONE NUMBER

NUMBER OF PERSONS INJURED

NATURE OF INJURY

2. POST OPERATOR TO DIRECT THE AMBULANCE
NAME, ADDRESS, PHONE OF INJURED PERSON

NAME^

ADDRESS

PHONE ^

3. GIVE ABOVE INFORMATION TO AMBULANCE CREW
NAME AND LOCATIOi^j OF HOSPITAL

HOSPITAL NAME

ADDRESS

PHONE

4. NOTIFY RELATIVES

5. NOTIFY SUPERVISORS

6. MAKE OUT ACCIDENT REPORT AS rjQON AS
POSSIBLE

438 Water Treatment

SUGGESTED ANSWERS

Chapter 20. SAFETY

ANSWERS TO QUESTIONS IN LESSON 1

Answers to questions on page 394.

20.0A A safety officer should evaluate every accident, offer
recommendations, and keep and apply statistics

20 OB The supervisors should be responsible for the imple-
mentation of a safety program.

20.0C Both state and federal regulatory agencies enforce
the OSHA requirements.

20.0D Each utility should develop a policy statement on
safety, giving its objective concerning the operator's
welfare. The statement sho'jid be brief, but give the
utility's recognition of the need for safety to stimulate
efficiency, improve service, improve morale and to
maintain good public relations. The policy should
recognize the human factor (the unsafe act), and
emphasize the operator's responsibility. The opera-
tors should be provided with proper equipment and
safe working conditions. Finally, the policy must
reinforce the supervisory respop-^ibility to maintain
safe work practices.

Answers to questions on page 395.

20.0E A supervisor may be responsible, in part or corr:-
pletely, for an accident by causing unsafe acts to
take place, by requiring that work be performed in
haste, by disregarding an unsafe environment of the
work /'ace, or by failing to consider any number of
safety hazards.

20.0F Each operator must accept, at least in part, responsi-
bility for fellow operators, for the utility's equipment,
for the operator's own v/elfare, and even for seeing
that the supervisor complies with establishea safety
regulations.

20.0G First aid means emergency treatment for injury or
sudden illness, before regular medical treatment is
available.

20.0H First aid training is most important for operators who
regularly work with electrical equipment and those
who must handle chlorine.

Answers to questions on page 399.

20.01 The mainstay of a safety program is the method of
reporting and keeping statistics.

20 OJ Even a minor injury should be reported because it
may be difficult at a later date to prove the accident
occurred on the job in order to have the utility accept
the responsibility for costs.

20.0K A safety officer should review an accident report
form tod) determine corrective actions and (2) make
recommendations.

20.0L A new Inexperienced operator must receive instruc-
tion on all aspects of plant safety. This training
includes Instruction in the handling of cnemicals, the
dangers of electrical apparatus, fire hazards, and
proper maintenance of equipment to prevent acci-
dents. Special instructions are required for specific
work environments such as manholes, gases (chlo-

rine and hydrogen sulfide (HpS)), wa^ir safety, and
any specific »-dzards that are unique to your facility.
All new operators should be subjected to a safety
orientation program during the first few days of
employment, and an overall training program in the
first few months.

20 OM If an operator Is unsure of how to perform a job, then
it is the operator's responsibility to ask for the
training needed.

Answers to questions on page 401.

20.0N Statistical accident reports should contain accident
statistics showing lost time, costs, type of injuries
and other data, based on some time interval.

20 OO Injuries can be classified as fractures, burns, bites,
eye injuries, cuts and bruises.

20.0P Causes of injuries can be classified as heat, machin-
ery, falling, handling chemicals, unsafe acts and
miscellaneous.

20.0Q Costs of accidents can be classified as lost time lost
doMars, lost production, contaminated water or any
other means of showing the effects of the accidents

ANSWERS TO QUESTIONS IN LESSON 2

Answers to questions on page 405.

201 OA An operator needs to know how to handle the
problems associated with the chemicals used in a
water treatment plant. The operator needs to know
how to store chemicals, the fire problem, the ten-
dency to "arch" in a storage bin, how to feed dry,
1- ow to feed liquid, and how to make up solutions.
Overheating gas containers, dust problems with
powdered carbon, burns caused by acid, reactivity
of each chemical under a variety of conditions that
may cause fire and explosions are other safety
hazard.*; that an operator needs to know about and
know how to control. Also, the operator .leeds to
know the usable limits because of toxicity, the
Protective equipment required for each chemical,
each chemical's antidote, and how to control fires
caused by each chemical.

20.11 A To give first aid vhen acid vapors are inhaled,
remove the victim to fresh air, restore breathing, or
give oxygen when necessary.

2011B Acetic acid will react violently with ammonium ni-
trate, potassium hydroxide and other alkaline mate-
rial.

20 lie Acetic acid can be handled safely the operator
uses adequate ventilation and prevents skin and
eye contact.

20.1 ID When handling hydrofluosilicic acid, always use
complete protective equipment including rubber
gloves, goggles or face shield, rubber apron, rub-
ber boots and have lime slurry barrels, epsom salt
solution and safety showers available. Always pro-
vide adequate ventilation.

20 1 1 E Inhalation of hydrochloric (HCI) vapors or mists can
cause damage to teeth and irritation to the nasal

ERIC

453

438 Water Treatment

SUGGESTED ANSWERS

Chapter 20. SAFETY

ANSWERS TO QUESTIONS IN LESSON 1

Answers to questions on page 394.

20.0A A safety officer should evaluate every accident, offer
recommendations, and keep and apply statistics

20 OB The supervisors should be responsible for the imple-
mentation of a safety program.

20.0C Both state and federal regulatory agencies enforce
the OSHA requirements.

Answers to questions on page 395.

20.0G First aid means emergency treatment for injury or
sudden illness, before regular medical treatment is
available.

20.0H First aid training is most important for operators who
regularly work with electrical equipment and those
who must handle chlorine.

Answers to questions on page 399.

20.01 The mainstay of a safety program is the method of
reporting and keeping statistics.

20 OJ Even a minor injury should be reported because it
may be difficult at a later date to prove the accident
occurred on the job in order to have the utility accept
the responsibility for costs.

20.0K A safety officer should review an accident report
form tod) determine corrective actions and (2) make
recommendations.

20 OM If an operator Is unsure of how to perform a job, then
it is the operator's responsibility to ask for the
training needed.

Answers to questions on page 401.

20.0N Statistical accident reports should contain accident
statistics showing lost time, costs, type of injuries
and other data, based on some time interval.

20 OO Injuries can be classified as fractures, burns, bites,
eye injuries, cuts and bruises.

20.0P Causes of injuries can be classified as heat, machin-
ery, falling, handling chemicals, unsafe acts and
miscellaneous.

20.0Q Costs of accidents can be classified as lost time lost
doMars, lost production, contaminated water or any
other means of showing the effects of the accidents

ANSWERS TO QUESTIONS IN LESSON 2

Answers to questions on page 405.

20.11 A To give first aid vhen acid vapors are inhaled,
remove the victim to fresh air, restore breathing, or
give oxygen when necessary.

2011B Acetic acid will react violently with ammonium ni-
trate, potassium hydroxide and other alkaline mate-
rial.

20 lie Acetic acid can be handled safely the operator
uses adequate ventilation and prevents skin and
eye contact.

20 1 1 E Inhalation of hydrochloric (HCI) vapors or mists can
cause damage to teeth and irritation to the nasal

ERIC

453

Safety 439

passages. Concentrations of 750 ppm or more will
cause coughing, choking and produce severe dam-
age to the mucous membranes of the respiratory
tract. In concentrations of 1300 ppm, HCI is danger-
ous to life.

2011F Nitric acid should be stored in clean, cool, well-
ventilated areas. The area should have sn acid-
»'esistant floor and adequate drainage. Keep away
from oxidizing agents and alkaline materials. Pro-
tect containers from damage or breakage. Avoid
contact with skin and provide emergency neutral-
ization materials and safety equipment in use
areas.

Answers to questions on page 408.

20 12A Operators use two forms of ammonia. The gaseous
form (anhydrous) and the liquid form (hydroxide)
are used by operators.

20.1 2B Care must be used when storing or transporting
ammonia containers. Always keep cyliiiders with
caps in place when not in use. S*ore cylinders In a
cool, dry location away from haat and protect from
direct sunlight. Do not store in the same room with
chlorine.

2C 2C The two forms of lime f^ed in water treatmei^t
plants are (1) hydrated lime (calcium hydroxide) and
(2) quicklime (calcium oxide).

20.12D If someone swallowed sodium hydroxide, give
large amounts of water or milk and immediately
transport t > a medical facility; do not induce vomit-
ing.

20.12E If sodium silicate comes in contact with your skin,
wash thoroughly with water, followed by washing
with a 1 0 percent solution of ammonium chloride or
10 percent acetic acid.

Answers to questions on page 412.

20.1 3A Chlorine leaks are most often found in the control
valve.

20.13B The purpose of the fusible metal plugs is to melt at
158 to 168°F. If a cylinder becomes overheated, the
plugs will melt and let the gas escape rather than
the cylinder bursting.

20.13C Chlorine leaks can be detected by the odor, by the
use of ammonia water on a small cloth or swab on a
stick, or by the use of an aspirator containing
ammonia water. (Remember not to spray ammonia
into a room full of chlonne because a white cloud
vvill form and you won't he able to see anything.)
A?so. a chlorine gas detec *or may be used.

20.13D Carbon dioxide is a safety hazard because it is
0'*'''!ess. colorless, and will accumulate at the
Ic Bt possible level. Carbon dioxide will displace
oxygen so you must use a self-contained breathing
apparatus.

Answers to questions on page 414.

20.1 4A For handling most ^^alts. ventilation, respiratory
protection and eye protection will prove adequate.

20.1 4B First aid when liquid or dry alum gets into the eyes
consists of flushing them immediately *or 15 min-
utes with large amounts of water. Alum should be
washed off the skin with water because prolonged
contact will cause skin irritation.

20 14C When exposed to moist atr or light, ferric chloride
oecomposes ani gives off hydrochloric acid.

Answers to qu' I'ons on page 415.

20.15A Potassium pernrianganate spills can be swept up.
Flushing with water is ari effective way to eliminate
spillage on floors.

20 158 Powdered activated carbon is the most dangerous
powder the water treatment plant operator will be
exposed to.

20.1 5C Activated carbon should be stored in a clean, dry,
fire-proof location. Keep free of dust, protect from
flammable materials, and do not permit smoking in
the area at any time when handling or unloading
activated carbon.

20.1 5D The key to preventing activated carbon fires is
keeping the storage area clean and free of dust.

20.15E Carbon fires should be controlled by carbon dioxide
(COj) extinguishers or hoses equipped with fog
nozzles. An activated carbon fire should not be
doused with a stream of water. The water may
cause burning carbon particles to fly, resulting in a
greater fire problem.

Answers to questions on page 415.

20.1 6A Safety regulations prohibit the use of common
drains and sumps from chemical storage areas to
avoid the ^possibility of chemicals reacting and
producing toxic gases, explosions and fires.

20.168 If a polymer solution comes in contact with potas-
>ium permanganate, a fire could devciOp.

ANSWERS TO QUESTIONS IN LESSON 3

Answers to questions on page 420.

20.2A Class A fires involve miscellaneous combustible ma-
terials. These include fabrics, paper, weed, dried
grass, hay and stubble.

20.28 Foam extinguishers can control Class A and Chss B
fires. They can control ordinary combustit:les ("A^
such as fabrics, paper, wood and grass, as well as
flammable liquids and vapors ("8^ such as oils,
lacquers, fats, waxes, paints, petroleum products
and gas.

20.2C An electrical fire can be extinguished by the use of
carbon dioxide (COj) extinguishers or with a dry
chemical extinguisher.

Answers to questions on page 421.

20.3A When waxing floors use compounds containing
nonslip ingredients. Warn others about newly waxed
floors. Try to do cleaning and waxing during off-duty
n^L?»'S, weekends or at night.

20.3B Rags are always a problem and if they contain oils,
paint or other cleaning compounds there is always
the possibility of fire. The rags should be placed into
a closed metal container to reduce the fire hazard.

20.3C When operating an overhead crane, the following
safety precautions must be exercised:

1. Allow only trained and authorized personnel to
operate the overhead crane,

2. Inspectthe circuit breaker, limit switches, condi-
tion of hook, wire rope and other safety devices,

460

440 Water Treatment

3. Post load limit on crane and never overload
crane,

4. Check each lift for proper balance,

5. Use a standard set of hand signals,

6. Be sure everyone in vicinity wears a hard hat,

7. Allow only authorized personnel to make re-
pairs,

8. Lock out the mam power switch before repairs
begin,

9 Try to avoid moving loads over populated areas,
aiid

10. Set up monthly safety inspection forms to be
filled out and placed into the maintenance file.

20 3D Traffic can be warned that operators are working in a
"^nhole by the use of barricades, signs, flags, lights
and other warning devices. Warning devices and
procedures must conform to local and state regula-
tions.

20.3E Operators should always use a mechanical lifting aid
(rope and bucket) for raising or lowering tools and
equipment into and out of a manhole. The use of a
bucket or basket will keep your hands free when
climbing down Into or out of a manhole.

Answers to questions on page 423.

20.3F Operators should wear eye and ear protection when
operating grinding, chipoing, buffing, or pavement-
breaking equipment. Sometimes when using grind-
ing or buffing tools, operators encounter toxic dusts
or fumes and therefore need respiratory protection.
At other times there is a need for full face protection
because of flying particles.

20.3G Operators can be protected from high noise levels by
wearing approved ear protection devices.

20.3H When operating welding equipment* the operator
should wear protective clothing, gloves, helmets and
goggles.

Answers to questions on page 425.

20.4A Tire wear Is caused by misalignment and low infla-
tion

20.4B fVlotor vehicles should have flashlights, flares, flags
and a first aid kit.

ANSWERS TO QUESTIONS IN LESSON 4

Answers to questions on page 429.

20.5A Each operator should become familiar with the type
of current and voltage in the plant in order to avoid
any mistake of becoming involved with unsafe elec-
trical circuits or practices for which they are not
trained. This will also permit operators to ask for a
qualified person to perform any necessary repairs.

20 58 Moving parts on electrical motors that require safety
guards include exposed couplings, pulleys, gears
and sprockets, as well as projections such as bolts,
keys, or set screws.

20.50 Two hazards due to the lack of a good lockout
procedure for control panels and switchboards are
(1) accidentally startinp a piece of equipment expos-
ing a fellow operator to a hazard, and (2) turning
electrical power on when someone is still working on
the equipment, exposing that person to danger.

ErJc Sc'>

Answers to questions on page 432.

20 6A Washing glassware is always a potential hazard
because the glassware can be broken while being
washed, causing cuts, or cuts can be caused by
chipped or cracked glassware. If your hands come in
contact with strong acir* cleaners, the acids may
cause serious burns.

20 6B When handling liquid chemicals such acids and
bases, always use safety glasses or face shields.

20 60 Never allow mercury, gasoline, oil or organic com-
pounds into the laboratory drains. Use only a toxic
waste disposal dram system for these items. Letting
such compounds down sink drains can cause an
explosion, allow toxic gases and vapors to enter the
lab or destroy the piping.

20.6D The plant operator may be exposed to radioactive
compounds when calibrating sludge density meters
or using research isotopes.

20 6E Never allow cold water into the hot boiler unit of a
water still because it may cause the unit to break.

Answers to questions on page 433.

20.7A When entering an oxygen-deficient atmosphere, you
should have an independent oxygen supply of the
positive-pressure type to protect you If there are any
leaks In your mask.

20.7B Respiratory apparatus must be stored outside of
chlorinating, sulfur dioxide, carbon dioxide, ozone
and ammonia rooms in an unlocked cabinet. The
storage cabinets must have a controlled environment
to prevent deterioration of the equipment.

20 70 Independent air supply equipment should be
checked out on a weekly basis, and records kept of
each inspection. The record should show conditions
of the hoses, regulators, air filters, compressors,
helmet and any other apparatus furnished with the
system.

20.7D To obtain compliance with an eye protection pro-
gram, supervisors should undertake an intense pro-
gram of education, persuasion, and appeal.

20 7E An operator needs eye protection when handling
many of the liquid chemicals, acids and caustics.
Many of the tests performed in the laboratory also
require eye protection.

Answers to questions on page 435.

20 7F Rubber boots are needed when handling acid or
caustic, or when tne operator is working in wet
conditions such as leservoirs, filters or chemical
tanks.

20.7G An operator should be very careful weanng gloves
when working around machinery that is revolving.

20.7H Operators should never work in a filter when it is
being backwashed because there is always the dan-
ger of falling Into the washwater gullet and being
unable to get out before drowning.

20 71 Before taking a boat out on the water, it should be
checked out for safety. The operator should check
the bilge pump, ventilation in tha compartments, the
safety cushions, fire extinguishers, battery and the
engine. For safety equipment, check oars, life jack-
ets, lights, mooring lines and fuel.

461

Safety 441

Answers to questions on page 435.

20.8A Operators should be prepared for catastrophic
events such as floods, tornados, hurricanes, fires
and earthquakes. Serious injuries to anyone on the
plant grounds Is an emergency.

20.8B If a senous CMemjcal emergency occurs such as a
chemical spill, leak, fire, exposure, or accident,
phone CHEMTREC, 800-424-9300

OBJECTIVE TEST

Chapter 20. SAFETY

Please write your name and mark the correct answers on
the answer sheet as directed at the end of Chapter 1. There
may be more than one correct answer to the multiple choice
questions.

TRUE-FALSE

1. The OSHA Law provides for civil penalties only.

1. True

2. False

2. Supervisors can prevent .nost accidents.

1. True

2. False

3. First aid training will prevent accidents.

1. True

2. False

4. On-the-job training is a good way of preventing acci-
dents for an inexperienced operator.

1. True

2. False

5. Acetic acid exposure must oe treated immediately to
prevent damage.

1. True

2. False

6. Potassium permanganate fires should be extinguished
with water.

1. True

2. False

7 Some weak bases will attack human tissue very rapidly
and cause burns.

1. True

2. False

8. Bases mjst be neutralized with dilute acids.

1. True

2. False

9. Ammonia gas is capable of forming explosive ixtures
v/ith air.

1. True

2. False

10 Never neutralize ammonia with an acid.

1. True
2 False

11. Quicklime is less caustic than hydrated lime.

1. "Trge

2. raise

1 2. When quicklime is mixed with water, a great deal o^ heat
IS generated and explosions can occur.

1. True

2. False

13. The loss of water supply to a lime slaker can create
explosive temperatures.

1. True

2. False

14. The storage area for chlorine cylinders must have force-
exhaust ventilation.

1. True

2. False

15. Never use an open flame on cylinders or pipes carrying
chlorine.

1. True

2. False

16. All safety equipment should be located inside the chlo-
rination room.

1. True

2. False

17. First aid for a sulfur dioxide victim is similar for the
victim of any acid injury.

1. True

2. False

18. Never use the same conveyor for quicklime and alum.

1 True
2. False

19. Ferric chlonde is an acid.

1. True

2. False

462

442 Water Treatment

20 Ferric chloride should be treated as you would treat any
acid.

1. True

2. False

21. Activated carbon burns without smoke or visible flame

1. True

2. False

22. Explosion-proof lighting must be used in paint booths,

1. True

2. False

23. Never use compressed air to clean off your clothing or
Darts of your body.

1. True

2. False

24. Never look at a welding operation without eye protec-
tion.

1. True

2. False

25. Chlorine may be the only chemical used in a simple well
system.

1. True

2. False

26. A special insulated mat should be used on the floor at all
switch boards.

1. True

2. False

27. Badly worn electrical cords should be used only in wet
locations.

1. True

2. False

28. In the laboratory, broken glass should be disposed of in
wastebaskets.

1. True

2. False

29. Always pour acid into water, nevf^-- the reverse.

1. True

2. False

30. Never enter a confined space with an explosive atmos-
phere.

1. True

2. False

MULTIPLE CHOICE

31. A safety officer should be responsible for

1. Applying accident statistics.

2. Evaluating every accident.

3. Implementing safety program.

4. Keeping accident statistics.

5. Offering recommendations.

32. A routine OSHA violation could cost an employer up to
for each violation.

1. $1000

2. $2500

3. $5000

4. $7500

5. $10,000

33. A supervisor could be responsible for an accident, in
part or complete, by

1. Causing unsafe acts to take place.

2. Disregarding an unsafe work environment.

3. Overlooking a potential hazard.

4. Requiring operators to attend safety meetings.

5. Requiring work to be performed in haste.

34. A review of accident causes shows that the accident
victim often has not

1. Accepted any responsibility for the safety program.

2. Acted responsibly.

3. Been concerned about fellow operators.

4 Been fully aware of the working conditions.
5. Complied with the safety regulations.

35. Tailgate safety meetings should be

1. Held where distractions can be avoided.

2. Held where everyone can hear.

3. Held in an auditorium.

4. Kept short.

5 Scheduled in a suitable location.

36. Hydrofluosilicic acid is

1. Corrosive.

2. Fuming.

3. Pungent.

4. Transparent.

5. Yellow.

37. Hydrochloric acid is highly reactive with

1. Amine.

2. Carbonate.

3. Glass.

4. Metals.

5. Porcelain.

38. Nitric acid

1. Attacks glass.

2. Attacks most metals.

3. Forms fumes in the presence of light.

4. Is a powerful reducing agent.

5. Is unstable even when properly handled.

39. Sulfuric acid may be contained in -lined contain-
ers.

1. Glass

2. Metal

3. Plastic

4. Rubber

5. Wooden

40. The most common strong bases are compounds of

1. Ammonia.

2. Calcium.

3. Carbonate.

4. Hypochlorite.

5. Sodium.

ERLC

463

Safety 443

41 . Sodium hydroxide

1. Absorbs carbon dioxide from the air.

2. Causes heat when mixed with water.

3. Dissolves human skin.

4. Is used to neutralize lime.

5. Is very hazardous to the operator.

42. Dissolving sodium hydroxide in water

1 Causes splintering.

2. Develops sludges.

3. Generates excessive heat.

4. Lowers pH.

5. Proajces mists.

43. Types of hypochlorite compounds used in water treat-
ment plants include

1 Calcium.

2. Iron.

3. Lithium

4. Magnesium.

5. Sodium.

44. Chlorine cylinders may be lifted using

1. Cableo.

2. Chains.

3. Clamps.

4. Cradles.

5. Ropes.

45. Chlorine cylinders should be stored

1, Below ground level.

2 In a clean, dry location.
3. On their sides.

4 So they cannot fall.

5. With the protective cap off.

46. Improper handling, storing or preparing solutions of
chemicals can cause

1. Burns.

2. Cost savings.

3. Explosions.

4. Illness

5. Loss of eyesight.

47. The most dangerous powder the water treatment plant
operator could be exposed to is

1. Alum.

2. Calcium carbonate.

3. Potassium permanganate.

4. Powdered activated carbon.

5 Quicklime.

48. The operator's BEST fire protection or prevention is

1. Anr-'^lly making a fire analysis of plant.
2 Good housekeeping.

3. Properly locating fire extinguishers

4. Providing suitable containers for used wiping cloths

5. Removal of fire hazards.

49. Class A fires involve

1. Electrical equipment.

2. Fabrics.

3. Oils.

4. Paints.

5. Sodium.

50. Hazardous atmospheric conditions that may be encoun-
tered in manholes include

1 Hyd'-ogen sulfide.
2. Insufficient oxygen.
3 Methane.

4. Natural gas

5. Nitrogen.

51. Which of the following rules apply to the operation of
gas or electric welding equipment'^

1. Adequate fire protection must be provided.

2. Have a buddy observe your performance.

3. Operators must be thoroughly trained.

4. Protection of other personnel must be provided and
used.

5 Work during regular hours only.

52. Types of safety valves in a water treatment Diant that
should be inspected and maintained on a regular basis
include:

1 Butterfly valves.

2. Chlorine relief valves

3. Gate valves.

^. Surge relief valves.

5. Water heater valves.

53 What safety precautions must be exercised around
vehicle wash and steam cleaning areas?

1. Always use scaffolding or platforms when cleaning
the tops of vehicles.

2 Check level of water on coils before turning on
steam.

3. Eye and face protection is not necessary.

4. Keep the steam nozzle clean.

5. Keep the wash rack free from oil and yrease.

54. Good drivers

1. Always observe traffic regulations

2 Check out their vehicles each time they use thern.

3 Drive defensively.

4. Operate vehicles as if all other drivers are the world's

worst drivers.
5 Use proper signals for directional change.

55 When safely operating a forklift, be sure to

1. Always face the direction of travel.

2 Check warning lights for proper operation.

3 Leave the power on when leaving the forklift to keep
the battery charged.

4. Never overload the forklift.

5. Use special lifting and retaining devices when han-
dling drums.

56, The purpose of most transformers where power enters
a water treatment plant is to

1. Decrease electrical resistance,

2. Detect overheating.

3. Increase the electrical voltage

4. Reduce the electrical voltage.

5. Transform low voltage to high voltage.

57. Hazardous conditions an operator may encounter in the
laboratory include

1. Alkalies.

2. Distilled water

3. Flammaole chemicals.

4. Glassware.

5. Toxic chemicals.

464

444 Water Treatment

58. Toxic chemicals, acids or alkalis can be transferred with
a pipet by using

1. Aspirators.

2. Pumps.

3. Suction bulbs.

4. Vacuum lines.

5. Your mouth.

59. Respiratory hazards in and around the treatment plant
that operators are exposed to on a daily basis include

1. Acids.

2. Bases.
3 Dusts.

4. Fumes.

5. Gases.

60. Types of gloves that an operator may need include

1. Asbestos fabric.

2 Cloth.

3. Leather.

4. Neoprene.

5. Rubber.

ERIC

405

CHAPTER 21

ADVANCED LABORATORY PROCEDURES

Jim Sequeira

446 Water Treatment

TABLE OF CONTENTS

Chapter 21 . Advanced Laboratory Procedures

Page

OBJECTIVES 447

LESSON

21.0 IJ'^e of a Spectrophotometer 448

21.1 Test Procedures* 449

1 . Algae Counts 449

2. Calcium , 45O

3. Chloride 45 -l

4. Color 453

5. Dissolved Oxygen 454

6. Fluoride 457

LESSON 2

7. Iron (Total) ^5^

8. Manganese 453

9. Marble Test (Calcium Carbonate Stability Te >t) 466

10. Metals 467

11. Nitrate , 468

12. PH 471

13. Specific Conductance 47-I

14. Sulfate 472

15. Taste and Odor 474

16. Trihalomethanes 479

17. Total Dissolved Solids 479

SUGGESTED ANSWERS

Cnapter 21. ADVANCED LABORATORY PROCEDUi'ifcS

ANSWERS TO QUESTIONS IN LESSON 1

Answers to questions on page 449.

21. OA The intensity of a blue color is measured when
measuring the concentration of phosphorus in water.

21. OB The scale in spectrophotometers i3 'jsudily graduat-
ed in two ways:

1 . In units of percent trarismittance (%T), a*. ur;^hr e-
tic scale witiT units graded from 0 to 100% aoo

2. In units of absorbance (A), a logarithmic seal*: of
nonequal divisions gradua'ed from O.O to 2.0.

21. OC If the absorbance reading w*.s 0.60, the unknown
concentration was 0.70 mg/L.

Answers to questions on page 453.

21.1 A Yes, the quality of water in any lake, reserve or
stream has a very direct effect on the abundance and
types of aquatic organisms found.

21 .1 B Calcium in the form of lime or calcium hydroxide may
be used to soften water or to control corrosion

ERLC

through pH adjustm<»nl.

21.10 Titrate sample for cairium immediately after adding
sodium hydroxide (NaOH) solKion.

21 ID Chlonde concentrations above 250 mg/L are objec-
tionable to many people due to a salty taste.

Answers to questions on page 453.

21. IE The most common colors which occur in raw water
are yellow and brown.

21 . 1 F True color is normally removed or at least decreased
by coagulation and chlonnation or ozonation.

21. 1G Stock color standards should be protected against
evaporation and contamination when not in use.

Answers to questions on page 460.

21. 1H The presence of dissolved oxygen (DO) in water can
contnbute to corrosion of piping systems.

21.11 The common range of fluoride in fluondated dnnking
water is 0.8 to 1.2 mg/L.

503

Lab Procedures 483

ANSWERS TO QUESTIONS IN LESSON 2

Answers to questions on page 465.

21.1 J Problems that may be caused by iron in a domestic
water supply include staining of laundry, concrete,
and porcelain. A bitter astnngent taste can be detect-
ed by some people at levels above 0.3 mg/L.

21.1 K All glassware must be acid washed when analyzing
samples for Iron to remove deposits of iron oxide
which could give false results.

21.1 L Manganese occurs both in suspension and as a
soluble complex in surface wat rs.

21,1 M If the manganese concentration cannot be deter-
mined immediately, acidify sample with nitric acid to
pH less than 2.

Answers to questions on page 468.

21 .1 N Temperature is important in the Marble Test because
the solubility of calcium carbonate varies with tem-
perature. Therefore, the test must be performed
immediately after the sample is collected and as
rapidly as possible.

21.10 Langelier Index ^ Initial pH - Final pH

^ 8.9 - 8.6

= 0.3

Since the Langelier Index is positive, the water is
supersaturated with calcium carbonate and not con-
sidered corrosjve.

21, IP The concentration of most mecals in water is deter-
mined by using atomic absorption spectioscopy or
colorimetric methods

Answers to questions on page 471.

21. 1Q In the nitrate test, all nitrate is reduced to nitrite and
then measured rolonmetrically.

21. '^R Removal of turoidity interfering with nitrate analyses
can be accomplished by one of the following meth-
ods to remove suspended matter that can clog the
reduction column.

1. Filter sample through a glass fiber or a 0.45
micron pore size filter ar. long as the pH is less
than 8, or

2. Add 1 mL zinc solution to 100 mL of sample and
mix thoroughly. Add enough sodium hydroxide
solution to obtain a pH of 10.5. Let treated sample
stand a few minutes to allow the heavy flocculent
precipitate to settle. Clarify by filtering through a
glass fiber filter.

21 IS The pH of natural waters is controlled by the relative
amounts of carbon dioxide, bicarbonate, and carbon-
ate ions.

Answers to questions on page 474.

21. IT Specific conductance or conductivity Is a numerical
expression (expressed in micromhos per centimeter)
of the ability of a water to conduct an electrical
current. This number depends on the total concen-
tration of the mineral dissolved in the sample (TDS)
and ♦he temperature.

21.1 U Sulfate ions are of importance in water supphes
because of the tendency of appreciable amounts to

form hard scales in boilers and heat exchapgers.

21.1V A 50 mL sample from a well produced a turbidity
reading of 40 TU using a nephelometer. What was
the sulfate concentration in mg/L'?

Known Unknown

Sample Size, mL = 50 mL Sulfate, mg/L
Turbidity. TU = 40 TU

1. Determine the sulfate concentration from the
graph.

Sulfate Concentration, mg/L = 15 mg/L
2 Calculate the sulfate concentration in mg/L.

Sulfate, mg/L (Graph Sulfate, mg/L)(lOO mL)
Sample Size, mL
^(15 mg/L)(lOO mL)

50 mL
= 30 mg/L

Answers to questions on page 479.

21 .1W Tastes and odors can be cauced in drinking water by
algae, actinomycetes, bacteria, decaying vegetation,
metals and pollutants (most organic chemicals and
some inorganic chemicals). Dissolved inorganic salts
of copper, iron, manganese, potassium, soaium and
zinc can be detected by taste.

21 IX Calculate the threshold odor number (T.O.N.) for a
sample when the first detectable odor occurred when
the 12 mL sample was diluted to 200 mL (188 mL of
odor-free water was added to the 12 mL).

Known Unknown

A or Sample Size, mL = 1 2 mL T.O.N.
B or Odor-Free Water. mL = 188 mL

Calculate the threshold odor number, T O.N.
. Ajf B
A

12 mL 188 mL

TO N. =^

12 niL

Answers to questions on page 480.

21 1Y The principal source of chlorofor'^ and other tnhalo-
methar.es in dnnkmg water is 113 chemical interac-
tion of chlorine added for disinfection and other
purposes with the commonly present natural humic
substances and other precursors produced either by
normal o'-ganic decomposition or by the metabolism
of aquatic organisms.

21 .1Z Total Dissolved Solids' (TDS) refer to material that
passes through a standard glass-fiber disc and re-
mains after evaporation at 180°C.

er|c

504

484 Water Treatment

OBJECTIVE TEST

Chapter 21. ADVANCED LABORATORY PROCEDURES

Please write your name and mark the correct answers on
the answer sheet as directed at the end of Chapter 1 . There
may be more than one correct answer to the multiple choice
questions.

TRUE-FALSE

1 . Measuring the intensity of ihe color enables the concen-
tration of a substance in water to be measured.

1. True

2. False

2. The human eye is more precise than a spectrophotom-
eter.

1. True

2. raise

3 A sample which has a low color intensity will have a low
percent transmittance but a high absorbance.

1. True

2. False

4 In most natural waters calcium is the principal anion.

1. True

2. False

5 Chloride usually occurs in natural waters as a basic salt.
1. True

2 False

6. Usually the chloride content in water increases as the
mineral content decreases.

1. True

2. False

7 True color results from the presence of suspended
matenals.

1. True

2. False

8 The formation of a white flor during the DO test indi-
cates that there is DO present in the sample.

1. True

2. False

9 As the temperature of water increases, the DO satura-
tion value increases.

1. True

2. False

10. Always record temperature of water when collecting a
dissolved oxygen sample.

1. True

2. False

1 1 . Iron IS an abundant and widespread constituent of rocks
and soils.

1. True

2. False

1 2 Above a pH of 4.6 the solubility of the fernc iron species
increases considerably.

1 True

2 False

1 3 Colloidal ferric nydroxide may persist m smflll quantities
in surface waters that appear clear.

1 True
2. False

14. Manganese is much more abundant in the earth's crust
than iron

1. True

2. False

15. Manganese m surface waters occurs both in suspen-
sion and as a soluble complex.

1. True

2. False

16. During the Marble Test, the water being tested should
not be exposed to atmospheric carbon dioxide.

1 True

2 False

1 7 Nitrite represents the most completely oxidized form of
nitrogen found in water.

1. True

2. False

18. The nitrate test measures both nitrate and nitrite.

1. True

2, False

1 9 Taste and odor are sensory clues which provide ♦he first
warning of potential hazards in the environment.

1. True
2 False

20 Water taken from a groundwater source is more likely to
produce high ThM levels than most surface waters

1. True
2 F?>'<^9

MULTIPLE CHOICE

21 Analyses of which of the following water quality charac-
teristics are based on the measurement of color inten-
sity

1. Dissolved oxygen

2. Iron

3. Manganese

4. pH

5 Phosphorus

ERIC

505'

Lab Procedures 485

22. Color intensities can be converted to concentrations of
substances using

1. Amperometnc titration.

2 Nessler tubes

3 pH prohes

4 Pocket comparators.

5 Spectrophotometers.

23. The quality ot water in any lake, reservoir or stream has

a very direct effect on the of aquatic organisms

found in the water.

1 Absorbance

2 Abundance

3. Aliquots

4. Percent transmittance

5. Transparency

24. The recommended maximum allowable concentration
of chlonde in drinking water is

1. 50mg/L

2. lOOmg/Z-

3. 150 mg//-

4. 200 mg/L

5. 250 mg/L

25. Ions that interfere with ♦he chloride test include
1 Iron.

2. Orthophosphate.

3. Sulfide.

4. Sulfite.

5. Thiosulfate

26 Color in water supplies may result from

1. Copper.

2. hardness.

3 Iron.

4 Manganese.

5. Organic matter.

27 Precautions that must be exercised when using a dis-
solved oxygen (DO) probe include

1. ACidify the sample.

2. Keep the membrane in the tip of the probe from
drying out.

3 Keep the sample iced.

4. Periodically check the calibration of the probe.

5. Remove reactive compounds thai can interfere with
the output.

28. Samples being tested for fluoride must be distilled if the
samples contain exce sive amounts of

Aluminum.

2. Hardness.

3. Hexametaphosphate

4. Nitrate.

5. Sodium hydroxide.

29. Iron in a domestic watei stpply can cause

1. Bitter tastes.

2. Consumer complaints.

3. Corrosion.

4. Staining ;i concrete.

5. Staining of lau-^dry.

30 Objections to manganese in domestic waters include

1 CorrcG;vity.

2 Discolored di iveways.

3 Mardneoo.

4. Stained laun^'ry

5. Stained plumbing fixtures

31. Metals found in drinking water include

1 Calcium

2 Chloride

3. Iron

4. Nitrogen.
5 Sodium.

32 High levels of nitrate in a domestic water suppiy are
undesirable becau'je of

1. Hardness.

2 Health threat due to infant methemoglobinema

3 Laundry stains.

4 Nitrate stains.

5 Potential for stimulating excessive algae growth.
33. Alum coagulates most effectively at pH values near

1. 4.3

2. 5 6
3 68

4. 7.5

5. 8.3

34. Tastes and odors in drinking waters can be produced by

1. Algae

2. Bactena

3. Decaying vegetation.

4. Hardness.

5. Pollutants.

35 In potable waters TDS consists mainly of

1. Dissolved minerals.

2. Inorganic salts.
3 Organic matter.

4. Soluble acids.

5. Vitamins.

36 Calculate the threshold odor number (T.O.N) for a
sample when the first detectable odor occurred when
ihe 17 rnL sample was diluted to 200 mL (183 mL of
odor-free water was added to the 17 mL).

1 4

2 6

3 8

4 12
5. 17

end oC obleciiw lis^t

ERIC

5n«

CHAPTER 22

DRINKING WATER REGULATIONS

Tim Gannon

Revised
by

Jim Sequeira

488 Water Treatment

TABLE OF CONTENTS

Chapter 22. Drinking Water Regulations

Page

OBJECTIVES 491

GLOSSARY 492

LESSON 1

22.0 History of Drinking Water Laws and Standards 493

22.1 1986 Amendments to the Safe Drinking Water Act 494

22.10 Major Aspects 494

22.11 Schedule 495

22.2 Disinfectants and Disinfection by-products 496

22.3 Surface Water Treatment Rule (SWTR) 496

22.30 Requirements for Non-Filtered Systems 497

22.31 Requirements for Filtered Water Systems 497

22.32 Monitoring Requirements of the SWTR 497

22.33 Turbidity Requirements of the SWTR 497

22.4 Types of Water Systems 493

22.40 Community Water Systems 493

22.41 Non-Community Water Systems 493

22.5 Interim Primary Drinking Water Standards 498

22.50 Establishment of Drinking Water Standards 498

22.51 Types of Contaminants 498

22.52 Immediate Threats to Health 499

22.520 Bacteria . ..499

22.521 Nitrate 499

22.53 Setting Standards 499

LESSON 2

22.6 Primary Drinking Water Standards 5O1

22.60 Inorganic Chemical Standards 501

22.600 Arsenic 503

22.601 Barium 503

ER?C

Water Quality Regulations 489

22.602 Cadmium 503

22.603 Chromium 503

22.604 Fluoride 503

22.605 Lead 503

22.606 ^:ercury 503

22.607 Selenium 503

22.608 Silver 503

22.61 Organic Chemical Standards 504

22.610 Trichloroethylene (TCE) 505

22.61 1 1.1 -Dichloroethylene 505

22.612 Vinyl Chloride 505

22.613 1.1.1-Trichloroethane 505

22.614 1 .2-Dlchloroethane 505

22.615 Carbon Tetrachloride 505

22.616 Benzene 505

22.61 7 1 ,4-Dichlorobenzene (p-dichlorobenzene) 505

L ? Turbidity Standards 505

22.63 Microbiological Standards 506

22.630 Conform 506

22.631 Multiple-Tube Fermentation Method 506

22.632 Membrane Filter Method 506

22.633 Chlorine Residual Substitution 506

22.634 Draft Coliform Rule 506

22.635 Giardia 507

22.64 Radiological Standards 507

22.7 Secondary Drinking Water Standards 508

22.70 Enforcement of Regulations 508

22.71 Secondary Maximum Contaminant Levels 508

22.72 Monitoring 509

22.73 Secondary Contaminants 509

22.730 Chloride 509

22.731 Color 509

22.73? Copper 510

22.733 Corrosivity 510

22734 Fluoride 510

22.735 Foamiiig Agents 510

22736 Iron and Manganese 511

22.737 Iron 511

22 738 Manganese 511

ERIC

490 Water Treatment

22.739 Odor 511

22.740 pH 512

22.741 Sulfate 512

22.742 Total Dissolved Solids 512

22.743 Zinc 512

22.8 Sampling Procedures 513

22.80 Safe Drinking Water Regulations 513

22.81 Initial Sampling 51 3

22.82 Routine Sampling 51 3

22.83 Check Sampling 513

22.84 Sampling Points 513

22.85 Sample Point Selection 514

22.86 Sampling Schedule 515

22.87 Sampling Route 515

22.88 Sample Collection 515

22.9 Reporting Procedures 515

22.10 Notification for Community Systems 515

SUGGESTED ANSWERS

Chapter 22. DRINKING WATER REGULATIONS

ANSWERS TO QUESTIONS IN LESSON 1

Answers to questions on pr le 496.

22.0A The first c^: inking water standards were designed to
contrOi waterborne bacteria and viruses that can
C2jse diseases such as cholera, typhoid, and dysen-
tery.

22.1 A The major aspects of the 1986 Amendments to the
SDWA include:

1. Compulsory revisions to the regulations for new
contaminants,

2. Definition of an approved treatment technique for
each regulated contaminant,

3. Filtration requirement for surface water supplies,

4. Disinfection of all water supplies, and

ERIC

5. Prohibition of thr use of lead products In materials
used to convey Drinking water.

22.1 B Water systems will not be required to meet Phase I
regulations until two-and-a-half years after the law
was passed because the Act requires promulgation
of regulations within 12 months and an additional 18
months must be given for the states to adjust their
own regulations.

Answers to questions on page 498.

22.2A Trihalomethanes (THMs) are the product of chlorine
combining with organic material in the water; they are
suspected carcinogens.

22.3A The draft Surface Water Treatment Rule (SWTR)
specifically requires tha^

1. All r iace water systems must disinfect,

528 Water Treatment

2. All surface water systems must filter unless they
meet source water quality criteria and site-specific
conditions*

3. All systems will need to achieve the removal or
inactivation criteria of Giardia and enteric viruses,
and

4. Only qualified operators will be entitled to operate
the systems.

22.3B A water utility can avc 1 mandatory filtration by
meeting (1) source water quality criteria (coliforms
and turbidity levels), and (2) certain site-specific
conditions regarding disinfection, watershed control,
lack of waterborne disease outbreaks, compliance
with conform MCL, and total THM MCL.

Answers to questions on page 500.
22.4A A community water system is defined as follows:

1. Has at least 15 service connections used by all-
year residents, or

2. Services at least 25 all-year residents.

22.5A The five types of primary contaminants which are
considered to be of public health importanro are:

1. Inorganic contaminants,

2. Organic contaminants,

3. Turbidity,

"4. Microbiological contaminants, and

5. Radiological contaminants.

22.5 B Nitrate in drinking water above the national standard
poses an immediate threat to children under three
months of age. In some infants, excessive levels o^
nitrate have been known to react with intestinal
bacteria which change nitrate to nitrite which reacts
with henr^oglobin in the blood to produce an anemio
condition commonly known as "blue baby."

ANSWERS TO QUf '>t iN LESSON 2

Answers to questions on page j04.

22.6A Inorganic chemicals ^re metals, salts, and other
chemical compounds that do not contain carbon.

22.68 Arsenic is listed as a primary contaminant because
water that continuously exceeds the national stan-
dard by a substantial amount over a lifetime may
cause fatigue and loss of energy. Extremely high
levels can cause poisoning.

22.60 At levels of 6 to 8 mg/L fluoride may cause skeletal
fluorosis which is a brittling of the bones and stiffen-
ing of the joints. At levels of 2 mg/L and greater
fluoriae may cause dental fluorosis which is discolor-
ation and mottling of the teeth, especially in children.

22.6D Lead may enter drinking water from galvanized
pipes, solder used with copper pipes, and through
the air from auto exhausts.

Answers to questions on page 505.

22.6E Organic chemicals are either natural or synthetic
chemical compounds that contain carbon. Synthetic
organic chemicals (SOCs) are man-made com-
pounds that are widely used as pesticides, paints,
dyes, solvents, plastics, and food additives.

ERIC 549

22.6F Trichloroethylene (TOE) has been widely used as an
ingredient in many household products (spot remov-
ers, rug cleaners, air fresheners), dry cleanif.g
agents, industrial metal cleaners and polishes, refrig-
erants, and even anesthetics.

22.6G The monthly average turbidity MCL may not exceed
1 TU. At state option this may be raised to 5 TU.
Some states require 0.5 TU where there is a major
hazard of wastewater (sewage) contamination of the
water supply.

Answers to questions on page 508.

22.6H EPA is considering tha creation of MCLs for Giardia.
viruses, standard plate count, and Legionella.

22.61 For water systems that regulariy take 10 or fewer
samples per month, ONE positive sample may be
discarded if:

1. The system chlorinates and maintains a residual.

2. The system takes two check samples on consecu-
tive days, and

3. This exclusion has NOT been used in the previous
month.

22.6J The MCLs for radiological contaminants are divided
into two categories: (1) natural radioactivity which
results from well water passing through deposits of
naturally occurring radioactive materials; and (2)
man-made radioactivity such as might result from
industrial wastes, hospitals or research laboratories.

Answers to questions on page 509.

22.7A Secondary drinking water regulations are enforce-
able after a state has passed a law requiring the state
health agency to enforce the regulations.

22.7B The secondary drinking water contaminants include:

1. Chloride 8. Manganese

2. Color 9. Odor

3. Copper 10. pH

4. Corrosivity 11. Sulfate

5. Foaming Agents 12. Total Dissolved Solids

6. Fluoride 13. Zinc

7. Iron

22.70 Contaminants in the secondary regulations should
be monitored at intervals no less frequent than the
moi.iionng performed for inorganic contaminants
listed in the Interim Primary Drinking Water Regula-
tions or applicable to community water systems.
More frequent monitoring would be appropriate for
specific contaminants such as pH, color, odor or
others undftr certain circumstances as directed by
the state.

Answers to questions on page 511.

22.7D Chloride is a secondary contaminant because it
affects the aesthetic quality of water by imparting an
objectionable salty taste in water and because it
causes corrosion of the pipes in hot water and other
systems.

Water Quality Regulations 529

227E Copper usually gets Into drinking water from the
reaction of aggressive water on copper plumbing.

227F Reasons why corrosive waters are undesirable as
drinking water include:

1 Affects the aesthetic quality (turbid waters), and
causes taste and odor problems .n the water
supply;

2. Has senous economic 'mpact (loss of piping sys-
tems and water loss from leaks); and

3. Presents health implications (toxic corrosion
products such as lead, cadmium and copper).

22.7G The application of chlorine to waters containing
manganese increases the likelinood of precipitation
at low levels. Unless the precipitate is removed,
precipitates reaching pipelines will promote bacterial
growth.

Answers to questions on page ''•S.

22.7H The undesirable effects of abnormal pH values in-
clude:

1 . When the pH increases, the disinfection activity of
chlorine falls significantly;

2. High pH may cause increased halogen reactions,
which produce chloroform and other tnhalometh-
anes during chlorination;

3 Both excessively high and low pHs may cause
increased corrosivity which can in turn create
taste problems, staining problems, and significant
hea'*h hazards;

4. Metallic piping in contact with low pH water will
impart a metallic taste;

5. If piping IS iron or copper, oxide and carbonate
compounds will be deposited leaving red or green
stains;

6. At high pH, dnnking water acquires a bitter taste,
and

7. The high degree of mineralization often associat-
ed with basic waters results in encrustation of
water pipes and water-using appliances.

22.71 High levels of sulfate are undesirable because they:

1. Tend to form hard scales in bOuers and heat
exchangers,

2. Cause taste effects, and

3. Cause a laxative effect.

22.7J High levels of zinc are undesirable in dnnking water
because they:

1 Produce adverse physiological effects,

2. Impart undesirable tasted,

3. Cause a milky appearance in the water, and

4. May increase lead and cadmium concentrations.

22.8C '.Whenever an initial or routine sample analysis indi-
cates that an MCL has been exceeded, CHECK
SAMPLING IS required to confirm the routine sam-
pling results. Check sampling is in addition to the
routine sampling program.

22.8D At the very minimum, a small system with a popula-
tion of 100 people must sample for turbidity and
coliform bacteria and also must have two sampling
points.

1 One where the water enters the distribution sys-
tem, and

2 One at a consumer faucet at a point representa-
tive of the distribution system.

Answers to questions on page 515.

22.8E Information that should be specified in a sampling
program includes:

1. Sampling frequency,

2. Sampling point designation,

3. Location,

4 Type of test,

5. Sampie volume, and

6. Special handling instructions.

22.8F The following elements are necessary to the cc 'lec-
tion of an acceptable sample:

Obtain a sample that is truly representative of tne
existing condition,

2. Flush the line before sample collection,

3. Fill the sample bOiJe without leaving any air
pocket,

4. Analyze residual chlonne when the sample is
taken,

5. Maintain the sample so that it does not become
contaminated before it reaches the laboratory,

6. Use preservation techniques (pH control and re-
frigeration),

7. Keep accurate 3cords of every sample collected
(date, time, location, name of sample, bottle num-
ber, type of sample, and name of person collect-
ing sample), and

8. Keep the time between the collection of the sam-
ple and analysis as short as possible.

Answers to questions on page 527.

22.9A The two general categories of reporting called for by
the SDWA are:

1 . P^^norting to the public (public notification), and

2. Reporting to the state.

Answers to questions on page 514.

22.8A "Initial Sampling' refers to the very first sampling you
do under the Safe Drinking Water Act for each of the
applicable contaminant categories.

22.8B Routine sampling refers to sampling repeated on a
regular basis.

ERIC

22.9B The three type^ cf reports that must be sent to the
state are:

1. Routine sample reryorts,

2. Check sample reports, and

3. Violation reports.

2k lOARequired public notification for the violation of an
MCL includes mail, newspaper and broadcast.

530 Water Treatment

OBJECTIVE TEST

Chapter 22. DRINKING WATER REGULATIONS

Please write your name and mark the correct answers on
the answer sheet as directed at the end of Chapter 1 . There
may be more than one correct answer to the multiple choice
questions.

TRUE-FALSE

1 All public water systems must comply with the regula-
tions of the Safe Drinking Water Act

1 True
2. False

2 MCLs apply only to contaminants from man-mac ollu-
tion.

1. True

2. False

3. More types of contaminants must be monitored by non-
community than community systems.

1 True
2. False

4. MCLs have been established to indicate when a con-
form concentration could indicate the likely ptesence of
disease-causing bacteria.

1. True

2. False

5 Monitoring for natural radioactivity is required onh' for
groundwater community systems.

1. True

2. False

6. The concerns with inorganic chemicals In drinking water
are centered on cancer.

1. True

2 False

7 Coliform bacteria in water are used to indicate the
potential presence of pathogens

1. True

2. Falsi

8. Barium can enter drinking water through natural
sources in the environment or industrial waste dis-
charges

1. True

2. False

9 The health risk from mercury is greater from waterborne
mercury than simply from eating fish.

1 True

2 False

^0 Secondary drinking water regulations are federally en-
forceable

1 True
2. False

1 1 Map taste etfocts in water are produced by cations.

1 Trie

2 Fals-^

12 The level of color m water is a measure of the safety of
water

1 True

2 False

1 3 Rapid changes m color levels may produce more citizen
complaints than relatively high, constant color levels.

1 True

2 False

1 4 EPA dnnk'ng water regulations are called "intenm" regu-
lations because research continues on drinking water
contaminants.

1 True

2 False

15 Taste tests are less fatiguing than odor tests.

1 True

2 False

16 If a water doesn't have any taste or odor, then it is safe
to drink

1 True

2 False

17 Consumers can tolerate a wide range of pH values in
dnnking water

1 True

2 False

18 At low pH levels drinking water acquires a bitter taste.

1 True

2 False

19 Samples should be collected from consumers' faucets
which are representative of conditions within the distri-
bution system.

1. True
2 False

20 Check sampling is part of the rcjtine sampling program.

1 True

2 False

21 When samples are delivered to the lab. lab personnri
must complete the field data forms upon acceptance of
toe samples.

1 True

2 False

22 The pnmary purpose of the Safe Drinking Water Act is
to protect the public's health.

1. True

2. False

EMC

551

Water Quality Regulations 531

23 Sampling points must include representative locations
of each different water source entering the system

1. True
2 False

24 Sample lines should be flushed before collecting a
sample

1. True

2 False

25 Failure to comply with a testing procedure requires
notification of consumers by newspaper

1 True

2 False

MULTIPLE CHOICE

26. The regulations of the Safe Drinking Water Act which
operators must deal with extensively include

1 Maximum Contaminant Levels.

2. Reporting requirements.

3. Sampling and testing requirements.

4. Siting requirements.

5. Variations in the regulations.

27 Types o* primary conta.T»inants which are considered to
be of public health importance include

1. Corrosivity contaminants.

2. Foaming contaminants.

3. Inorganic contaminants.

4. Microbiological contaminants.
5 Turbidity

28. Contaminants which may affect public health after a
short-term exposure include

1. Microbtologica' contaminants.

2. Nitrate.

3 Organic chemicals.

4. Radiological chemicals.

5. Trihalomethanes.

The MCLs for organic chemicais presently include

1. Herbicides.

2. Oils.

3 Pestic'des.

4. Solvents.

5 Trihalomethanes.

30. The MCL established for total trihalomethanes (TTHMs)

1. 0.1 micrograms per liter.

2. 1.0 microgram per liter.

3. 0.10 milligrams per liter.

4. 1.0 milligram per liter.

5. 10 milligrams per liter.

31 . A stale may allow a water utility to reduce the frequency
of sampling for THMs arter taking into consideration

1. Age of persons living in community.

2. Health of community.

3. Level of natural organics in water.

4. Quality and stability of raw water.

5. Type of treatment.

ERIC

32. The Safe Drinking Water Act gave the U.S. Environmen-
tal Protection Agency the authority to

1. Establish uniform guidelines of drinking water tech-

ologies.

2. i$5.>-e NPDES permits to water purveyors.

3. Promulgate pretreatment effluent standards for
POTWs.

4. Require monitoring and reporting for public water
systems.

5. Set national standards for regulating levels of conta-
minants in drinking water.

33. The draft Surface Water Treatment Rule (SWTR) re-
quires that a disinfection residual of rng/L in 95

percent of the samples be maintained.

1. 0.2

2. 0.5

3. 1.0

4. 2.0

5. 5.0

34. Substances for which drinking water standards have
been set and which pose an immediate threat to health
whenever the standards are exceeded include

1. Arsenic.

2. Coliform bacteria.

3. Lead.

4. Mercury.

5. Nitrate.

35. Arsenic is commonly found in

1. Beverages.

2. Candy.

3. Food.

4. Shellfish.

5. Tobacco.

36. Cadmium can enter drinking water from

1. Canneries.

2. Electroplating.

3. Insecticides.

4. Metallurgy

5. Photographic processes.

37. Water with a high color content may indicate

1 High disinfection demand.

2 High organic chemical contamination.

3. High pH.

4. Inadequate treatment.

5. Potential for production of excess amounts of disin-
fection by-products.

38. Reasons why copper is undesirable in drinking water
include

1. Causes blue or green staining of porcelain.

2. Imparts some taste to water.

3. Kills algae.

4. Results in liver damage after prolonged doses.

5. Stains blond hair.

552

532 MTeter Treatment

39. True taste sensations include

1. Bitter.

2. Rotten.

3. Salty
4 Sour.
5. Sweet.

40. Undesirable effects from high levels of sulfate in drink-
ing water include causing

1. Formation of hard scales in boilers and heat ex-
changers.

2. Laxative effects.

3. Precipitation of calcium sulfate.

4. Taste effects.

5. Undesirable odors in water.

41 High levels of total dissolved solids are undesirable in
drinking water because they cause

1. Adverse tastes.

2 Deterioration of distribution systems.

3. Precipitates to form in boilers.

4. Sludge in freezing processes

5. Water to be reused more often.

42. Which of the following actions are required o^ operators
by the Safe Dnnking Water Act?

1. Organizing

2. Recordkeeping

3. Reporting

4. Sampling

5. Testing

43. When you start and when you finish your Initial Sam-
pling" program depends on

1. Available budget.

2. Option exercised by state.

3. Type of contaminant being monitored.

4. Whether the system is a community or non-commu-
nity water system.

5. Whether the water source is a surface or a ground-
water supply.

44. Samples should be collected at the consumers* faucet
for which of the following contaminants?

1. Coliform ^actena
2 Inorganics

3. Organics

4. Radiochemicals

5. Turbidity

45. Community systems must sample for radioch'^micals
every

1. Six months.

2 Year.

3 Two years.
4. Three years.
5 Four years.

46. To collect an acceptable sample you must

1. Flush the line before sample collection.

2. Keep the time between sample collection and analy-
sis as long as possible.

3. Obtain a sample truly representative of the existing
condition.

4. Use preservation techniques.

5. Use the proper reporting form.

ERIC

553

Water Quality Regulations 533

APPENDIX

Coiiform Samples Required Per Population Served

Population Served

Minimum Number of
Samples per Month

25 to 1,000 1t

I, 001 to 2,500 2

2,501 to 3,300 3

3,301 to 4,100 4

4,101 to 4.900 5

4,901 to 5,800 6

5,801 to 6,709 7

6,701 to 7,600 8

7,601 to 8,500 9

8,501 to 9, 400 10

9,401 to 10,300 11

10,301 to 11,100 12

II, 101 to 12,000 13

12.001 to 12,900 14

12,901 to 13,700 15

13,701 to 14,600 16

14,601 to 15,500 17

15,501 to 16,300 18

16,301 to 17,200 19

17,201 to 18,100 20

18,101 to 18,900 21

18,901 to 19,800 22

19,801 to 20,700 23

20,701 to 2 1,500 24

21.501 to 22,300 25

22,301 to 23,200 26

23,201 to 24,000 27

24.001 to 24,900 28

24,901 to 25,000 29

25.001 to 28,000 30

23.001 to 33,000 35

33,001 to 37,000 40

37.001 to 41.000 45

41.001 to 46.000 50

46.001 to 50,000 55

50.001 to 54,000 60

54.001 to 59,000 65

59.001 to 64,000 70

64.001 to 70 000 75

70.001 to 76,000 80

76.001 to 83.000 85

83.001 to 90,000 90

Population Served

Minimum Number of
Samples per Month

90,001 to 96,000 95

96,001 to 111,000 TOO

111,001 to 130,000 110

130,001 to 160,000 120

160,001 to 190,000 130

190,001 to 220,000 140

220,001 to 250,000 150

250,001 to 290,000 160

290,001 to 320,000 170

320,001 to 360,000 180

360,001 to 410,000 190

410,001 to 450,000 200

450,001 to 500,000 210

500,001 to 550,000 220

550,001 to 600,000 230

600,001 to 660,000 240

660,001 to 720,000 250

720,001 to 780,000 260

780,001 to 840,000 270

840,001 to 910,000 280

910,001 to 970,000 290

970,001 to 1,050,000 300

1,050,001 to 1,140,000 310

1,140.001 to 1,230,000 320

1,230.001 to 1,320,000 330

1.320.001 to 1,420,000 340

1,420.001 to 1.520.000 350

1.520,001 to 1.630,000 360

1.630,001 to 1.730.000 370

1,730,001 to 1.850.000 380

1.850,001 to 1,970,000 390

1,970,001 to 2,060,000 400

2,060,001 .to 2,270,000 410

2,270,001 to 2,510.000 420

2,510.001 to 2,750,000 430

2.750.001 to 3.020.000 440

3.020.001 to 3.320,000 450

3.320.001 to 3,620,000 460

3.620.001 to 3.960,000 470

3.960.001 to 4.310,000 480

4.310.001 to 4.690,000 490

More than 4.690,001 500

Source: EPA

t . k community water system serving 25 to 1 .000 persons, with written permission from the state, may reduce this sampling frequency, ex-
cept in no case sh ill it be reduced to less than one per quarter The decision by the state will be based on a history of no coiiform bacte-
rial contamination for that system and on a sanitary survey by the state showing the water system to be supplied solely by a protected
groundwater source, free of sanitary defects.

ERIC

CHAPTER 23

ADMINISTRATION

Tim Gannon

Revised
by

Jim Sequeira

ERIC

536 Water Treatment

TABLE OF CONTENTS

Chapter 23. Administration

Page

OBJECTIVES 538

23.0 Office Procedures 539

23.00 Budgeting 539

23.01 Water Rates 54O

23.02 Procurement of Materia! 541

23.03 Treatment Plant Records 543

23.030 Purpose of Records 543

23.031 Types of Records 543

23.032 Types of Plant Operation Data 544

23.033 Maintenance Records 544

23.034 Inventory Records 544

23.035 Equipment Records 545

23.036 Disposition of Plant Records 545

23.04 Organizational Planning 545

23.1 Personnel Administration 547

23.10 Supervision 547

23.11 Staffing 547

23.12 Training 543

23.13 People 543

23.14 Operator Certification 549

23.140 Need for Certified Operators 549

23.141 Why Should Water Utility Operators Te Certified? 549

23.1410 Safety 549

23.1411 P action of the Public's Investment 549

23.1412 Employee Pride and Recognition 549

23.142 ABC 549

23.2 Public Relations 549

23.20 Establish Objectives 549

23.21 Utility Operation 549

23.22 The Mass Media 55O

23.23 Being Interviewed 55O

ERLC

556

Administration 537

23.24 Public Speaking 550

23.25 Telephone Contacts 551

23.26 Customer Inquiries 551

23 27 Plant Tours 551

23.3 Emergency Planning 552

23.4 Hanoling the ^Tireat of Contaminated Water Supplies 553

23.40 !rT^po»1ance 553

23.41 Toxicity 553

23.42 Effaaive Dosages 554

23.43 Protective Measures 554

23.44 Emergency Countermeasures 554

23.45 In Case of Contaminiation 555

23.5 Additional Reading 556

Discussion and Review Questions 556

SUGGESTED ANSWERS

Chapter 23. Administration

Answers to questions on page 541 ,

23.0A Budgeting is the art of predicting the amount of
money necessary to achieve an organization's goals.

23,0B Waste and inefficiency can be reduced or eliminated
by carefully examining all phases of operation and
maintenance when preparing accurate and realistic
budgets.

23.0C Important items usually contai'^d on a purchase
Order include: (1) the date, (2) a complete description
of each item and quantity needed, (3) prices, (4) the
name of the vendor, and (5) a purchase order num-
ber.

Answers to questions on page 545.

23.0D Some of the important uses of records include:

1 Aiding operators in solving treatment and water
quality problems,

2. Providing a method of alerting operators to
changes in source-water quality,

3. Showing that the treated water is acceptable to
the consumer,

4. Documenting that the fihal product meets plant
performance standards^ as well as the stan-
dards of the regulatory agencies.

5. Determining performance of treatment pro-
cesses, equipment, and the plant,

6. Satisfying legal requirements,

7. Aiding in answering comp'amts,

8. Anticipating routine maintenance,

9. Providing data for cost analysis and prepara-
tion of budgets,

10. Providing data for future engineering designs,
and

11. Providing information for monthly and annual
reports.

23.0E "Unaccounted for water" is the difference between
the amount of treated water that enters the distribu-
tion system and waterthat is delivered to consumers.

23.0F Chemical inventory and usage records that should be
kept include:

1. Chemical inventory/storage (measured use and
deliveries),

2. Metered or estimated plant usages, and

3. Calculated usage of chemicals (compare with
actual use).

Answers to questions on page 547,

23.0G Guidelines which are useful in development of an
organizational plan include:

1. Organization should be based specifically upon
the objectives to be achieved and the activities to
be performed,

ERIC

2. Each person should have only one boss and all
direction and guidance should come from that
supervisor,

3. The number of supervisory levels above the
working level should be kept to a minimum,

4. Each supervisor should have a limited number of
people to directly supervise (fewer than 6),

5. Delegation of authority should be as complete as
possible with the lowest levels of the work force
allowed to make as many decisions as are ap-
propriate to that level,

6. The responsibility for performance of each indi-
vidual should be pre-determined and then made
perfectly clear to the individual and the staff, and

7. Lines of management authority must be main-
tained and not weakened by staff or functional
authority.

23.0H The staff organization provides advice and service to
the line personnel to assist them in meeting their
objectives.

23.01 Organizational planning can benefit manag ,ient by
correcting weaknesses in the organization of a utility.
It can also strengthen the structure and increase the
effectiveness of management, thereby reducing
costs and increasing efficiency,

23.0J Signs that may indicate to a utility potential weak
points or approaching organizational problems in-
clude:

1. Physical, mental and emotional overloading
which causes undue fatigue,

2. Indecisiveness in management which delays de-
cision rraking,

3. Poor teamwork resulting from poor supervisory
practices or personal inadequacies of a supervi-
sor, and

4. Failure to train subordinates which causes prob-
lems when supervisors are promoted or move on
to another job.

Answers to questions on page 548.

23 1 A A supervisor is responsible for the safety and profes-
sional development of operators. Other responsibil-
ities may include assigning tasks to specific opera-
tors, being sure they understand the assignment and
know how to do the job safely, and eventually making
sure that the job was done properly.

23.1 B The most important factors which will influence the
size and qualifications of staff required include the
number of services and also the size and complexity
of the treatment processes and facilities that must be
operateo and maintained. Other important factors
might include age and condition of facilities and
expected population growth rates,

23.1 C Operators should be properly trained to recognize all
hazards and to effectively accomplish the tasks they
are assigned. Supervisors must motivate operators

578

558 Water Treatment

to use safe procedures.

Answers to questions on page 549.

23.1 D Water supply and treatment facilities are often classi-
fied on the basis of the number of services and/or the
capacity of the treatment plant as well as on the
complexity of the treatment processes in the plant.

23.1 E An operator can achieve higher levels of certification
by gaining the necessary education and experience
for the next level of certification. The operator then
must successfully pass the next level certification
examination.

23.1 F To find out how to become certified, contact your
state certification board or the Association of Boards
of Certification (ABC) in Ames. Iowa.

Answers to questions on page 552.

23.2A Probably the single most important aspect of a public
relations effort is employee job satisfaction and
performance.

23.2B Management should try to develop among its em-
ployees the attitude that even though the consumer
is not always right, every consumer is always entitled
to courteous treatment and a proper explanation of
anything the consumer does not understand.

23.2C Proper preparation for an interview with the news
media includes:

1. Speak in personal terms, free of institutional
jargon.

2. Do not argue or show anger if the reporter
appears to be rude or overly aggressive.

3. If you don't know an answer, say so and offer to
find out. Don't bluff.

4. If you say you will call back by a certain time, do
so. Reporters face tight deadlines.

5. State your key points early in the interview,
concisely and clearly. If the reporter wants more
information, he or she will ask for it.

6. If a question contains language or concepts with
which you disagree, don't repeat them, even to
deny them.

7. Know your facts.

8. Never ask to see a story before it is printed or
broadcast. Doing so indicates that you doubt th.'*

reporter s ability and professionalism.

23.2D Plant tours are an excellent method of informing the
public of the water utility's efforis to provide a safe,
wholesome witer supply.

Answers to questions on page 553.

23.3A The first step towards an effective contingency plan
for emergencies is to make an assessment of vulner-
ability. Then a comprehensive plan of action can be
developed and implemented.

23.3B Adequate chlorination is effective against most bio-
logical agents during an emergency. Othe:* consider-
ations include the amount of dilution water and the
possibility that the biological agents will die off during
normal detention times with adequate chlorination.

23.3C A detailed emergency operation plan is not needed
since all types of emergencies cannot be anticipated
and a complex response program can be more
confusing than helpful.

23.3D An emergency operations plan should include:

1 . Vulnerability assessment,

2. Inventory of personnel,

3. Provisions for recovery operation,

4. Provisions for training programs for operators in
carrying out the plan,

5. Inclusion of coordination plans with health, po-
lice and fire departments,

6. Establishment of a communications procedure,
and

7. Provisions for protection of personnel, plant
equipment, records and maps.

Answers to questions on page 555.

23.4A Toxicity is the ability of a contaminant (chemical or
biological) to cause injury when introduced into the
body.

23.4B The degree of toxicity varies with the concentration
of contaminant required to cause injury, the speed
with which the injury takes place, and the severity of
the injury.

23.4C Possible secondary effects in a water supply which
may allow detection of a contaminant without specif-
ic testing include taste, odor, color and chlori.'»e
demand.

ERLC

579

Administration 559

OBJECTIVE TEST

Chapter 23. ADMh>JlSTRATION

Please write your name and mark the correct answers on
tne answer sheet as directed at the end of Chapter 1 There
may be more than one correct answer to the multiple choice
questions

TRUE-FALSE

1 A definite plan of organization is essential to effectively
operate a v/ater treatment plant

1 True

2 False

2 The staff organization is in the line of command

1 True

2 False

3 Organizational plans can be copied from one maior
utility to another

1 True

2 False

4 Radio end television give more thorough coverage of
stones than newspapers

1 True

2 Faise

5 Usually the same vul."»erable plant element appears as a
problem for a variety of disaster events

1 True

2 False

6 Operators must be availaoie during nights, v/eekends.
and holidays to respond to emergencies

1 True

2 False

7 In a water treatment plant continuity of supply is of
prime importance

1 True

2 False

8 A set of rules can be established that will apply to all
types of people with consumer complaints

1 True

2 False

9. Try to be friendly and courteous at all times to people
with complaints.

1 True

2 False

10 Complaints should be welcomed and ac^^urately re-
corded

1 True

2 False

MULTIPLE CHOICE

1 1 A clear-cut organizational plan reduces or avoids

1. Confusion.

2 Duplication of effort.

3 Effective communication.

4 Fnction

5 Working at cross purposes

12 Each supervisor should supervise no more than

people.

1 6

2. 12

3. 18

4. 24

5. 30

13 Staff personnel shown on a water utility organization
chart include

1 Accountants.

2 Lawyers.

3 Operators.

4. Secretaries.

5. Superintendent.

14 Water utility operators stiojld become certified to

1 Be able to do a better job of operating the facilities.

2. Improve the utility's safety record.

3. Increase employee pride and recognition.

4. Learn how to identify safety hazards.

5 Protect the public's investment in the utility.

15 Management has a responsibility to keep employees
well informed about the organization's

1 Personnel actions (firings and demotions).

2. Plans.

3. Practices.

4 Purposes.

5. Union dues.

16 Management can keep employees well informed by
using

1. Bulletin board announcements

2. Local newspapers

3. Memos.

4. Straight talk from supervisors to subordinates.

5 The office gossip.

17 Information provided during a plant our should include

1 Description of the sources of water supply.

2 Information on quality of water distributed to con-
sumers

3 Plans for improvement.

4 Plant design features.

5 Theory of hydraulic turbulence in sedimenta.ion
basins.

ERIC

5S0

560 Water Treatment

18. Emergencies that confront water utilities include

1. Budget cuts.

2. Employee strikes.
3 Fires

4. Floods.

5. Vandalism.

19 Elements of a water utility which are most likely to be
weak points during a disaster include

1. Absence of trained personnel to make critical deci-
sions.

2. Inadequate amount of supplies and materials.

3. Inadequate communication equipment

4. Loss of power to the treatment facilities.

5. Shortage of funds to pay contractors.

20. The first step in organizing an effective public relations
campaign is to

1. Call a press conference.

2. Conduct plant tours.

3. Establish objectives.

4. Meet with community leaders.

5. Publish brochures.

21 . When responding to consumer complaints or questions,
proper response phrases include

1. Will you please.

2. You made a mistake.

3. You should have.

4. Your complaint.

5. Your question.

22 To help your utility make friends with people who
contact the agency by phDne. you should

1 Answer after 3 or 4 nngs so callers will know you are
busy

2. Answer by saying Hello '

3 Extend a pleasant greeting.

4 Leave word when away from ihe phone.

5 Route the call to someone who can take a message.

23 When determing the effective dosage of a contaminant
(the amount of that contaminant necessary to cause
injury), which of tha following facts must be considered?

1 . Duration of exposure to the contaminant

2 Quality or concentration of the contaminant

3 Sensitivity of consumers to the contaminant

4 Solubility of tne contaminant

5. Who is trie suspected source of the contaminant

24. Accurate records are very important because they

1 Are a valuable source of information.

2 Can save time when trouble develops.

3. Help prepare preventive maintenance progranrs.

4. Provide proof that problems were identified and
solved.

5. Serve as a basis for plant operation.

/•'■ r.

APPENDIX

Final Examination

How to Solve Water Treatment Plant
Arithmetic Problems

Water Abbreviations

Water Words

Subject Index

ERLC

582

WATER TREATMENT PLANT OPERATION

VOLUME II

FINAL EXAMINATION
AND

SUGGESTED ANSWERS

583

Final Exam 563

FINAL EXAMINATION

This final exar.iinaiion was prepared TO HELP YOU
review the material in this manual. The questions are divided
into four types:

1. True-False.

2. Multiple Choice.

3. Short Answers, and

4. Problems.

To work this examination:

1. Write the answers to each question in your notebook.

2. After you have worked a group of questions (you aecide
how many), check your answers '"'^h the suggested
answers at the end of this exam, ana

3 If you missed a question and don't understand why.
reread the material in the manual.

You may wish to use this examination for review purposes
when preparing for civil service dnd certification examina-
tions.

Since you have already completed this course, you do not
have to send your answers to California State University.
Sacramento.

True-False

1. Iron and manganese are essential to the growth of
many plants and animals, including humans

1. True

2. False

1 Only one cell of iron bacteria is needed to start an
infestation of iron bacteria in a well

1 *. rue
2. False

3. Fumes from hydrofluosilicic acid are safe to breathe

1. True

2. False

4 Insoluble deposits should be removed from chemical
feed lines.

1. True

2. False

5 In the lime softening process, magnesium is precipi-
tated out as magnesium carbonate.

1. True

2. False

6. Acid softening may be used instead of soda ash soften-
ing.

1 True
2. False

7 Dry ice should be used to keep THM samples cool when
shipping and storing.

1. True

2. False

8. THMs are produ-^ed faster in corrosive waters than m
scale forming waters

1 True

2 FaLse

9 When h gher mineral concenlralions occur in the feed-
water the mineral concentrations will decrease in tne
product water

1 True

2 False

10 An increase in feedwater temperature will decrease the
v^aler fi jx

1 True

2 False

1 1 Sedimentation lanko should be inspected and repaired
when the tanks are emptied and cleaned.

1 True

2 False

1 2 A precoat of filler sand js required to dewater gelatinous
alum sludge when using a vacuum filler.

1 True

2 False

13 Fiefore attempting to cnange fuses, turn off power and
check both power lines for voltage.

1 True

2 False

ERLC

584

564 Water Treatment

Mechanical energy ss commonly converted to electricat
energy by electric motors.

1 True

2 False

Always replace sprockets when replacing a chain.

1 True

2 False

Multiple Choice

1 Red water complaints in drinking water may be caused
by

1 . Corrosive v/ater

2 Ferric hydroxide

3 Iron bacteria

4 Iron in the water

5 Red clay or snt

16 A transducer is the primary element that measures a
variable,

1 True

2 False

17 Thin rubber or plastic gloves can be worn to reduce
markedly your chances of electrical shock

1 True

2 False

18. If an operator is unsure of how to perform a ]ob. then it
IS the operator s responsibility to ask for the training
needed

1. True
2 False

19 Inhalation of hydrochloric (HCl) vapors or mists can
cause damage to the nasal passages.

1 True

2 False

20 Distilled water is considered pleasant to drink.

1 True

2 Faise

21 Dissolved oxygen m water can contribute to corrosion
of piping systems

1 True

2 False

22 If the manganese concentration in a sample cannot be
determined immediately, acidify the sample with acetic
acid

1 "^rue

2 False

2 Chemicals used to oxidize iron and manganese include

1 Alum

2 Chlorine.

3 Hydrogen sulfide.

4 Lime.

5 Potassium permanganate

3 Important features of a fluoridation sys;em include
prevention of

1. Backsiphonage.

2 Leaks

3 Monitoring.

4 Overfeeding.
5. Underfeeding.

4 When shutting down a fluoride chemical feed system,
operators should

1 Confirm that safety guards are in place.

2. Dram and clean the mix and feed tanks.
3 Examine all fittings and drains for leaks.
4. Flush out all solution lines.

5 Inspect all equipment for binding and rubbing.

5 Benefits that could result from the lime-soda ash softei
r.g process include

1. Control of corrosion.

2 Increase in sodium content of softened water

3 Increase in water hardness.

4. Reduction in sludge disposal problems.
5 Removal of iron and manganese

6 Records that should be kept by the operator or an ion
exchange softening plant include

1. Blend rates.

2 Gallons of bnne used each day.

3 Pounds of lime used each day.

4 Results of jar tests.

5 Total flow per day that bypasses unit

23 Non-commu iity water systems serve consumers less
than 60 days per year

1 True

2 False

24. The MCL compliance for tnhalomethanes is determined
by the running average of four monthly averages

1. True

2. False

25. An acute toxic agent causes injury to occur over an
extended period of time.

1. True

2. False

ERIC 58

7 A minimum of — samples per quarter (every 3 months)
for THM analysis must be taken on the same day for
each treatment plant in the distribution system.

1 2

2 4

3 6

4 8

5 10

8 Group 1 techniques for contrc'ling THMs include

1 Aeration.

2 Chloramines.

3 Chlorine dioxide.

4 Ozone

5 Potassium permanganate

Final Hxam 565

9 The reverse osmosis elements should be cleaned v^^hen
the operator observes

1. Higher differential pressures
2 Higher operating pressures

3. Higher suspended solids in product water.

4. Lower product water flow rate

5. Lower salt rejection

10. Problems encountered in electrodialysis operation in-
clude

1. Alkaline scales in the concentrating compartments.

2 Fouling of m^.nbranes

3 Sealing of membranes by inorganic materials.

4. Sealing oi membranes by organic materials.

5. Strengthening oi membranes.

1 1 S'udge ma> oe dewatered by the use of

1 Belt filter presses.

2. Centrifuges

3. Flocculators.

4 Solar lagoons.

5. Solids-conlact units.

12 Problems created by discharging sludge to sowers
include

1 . Fees charged could be very high.

2. Increasing flow capacity of sewers.

3 Monitoring requirements increase.

4 Operational problems may develop at wastewater
treatment plant.

5 Possibility of causing a sewer blockage.

13. A good maintenance record system tells

1 How to handle consumer complaints.

2. Performance of equipment

3. QuaiJty of raw water.

4. Quality of treated water.

5. When maintenance is due.

14 A voltage tester can be useo to test for

1 Blown fuses

2. Grounds.

3. Open circuits.

4. Single phasing of motors.

5. Voltage.

15 Before a prolonged shutdown, pi mps should be
drained to prevent damage fiom

1. Cavitation.

2. CoTOSion.

3. Freezing.

4. Sedimentation

5. Water hammer,

16 Velocity sensing devices measure flows by sensing

1. Inches of water (head).

2. Loss of hydraulic energy
3 Pressure differential.

4. Pressure within a restriction.

5. Rate of rotation.

17. Reliable operation of pneumatic instrumentation pres-
sure systems requires

1. Ciean air.

2. Dry air.

3. Moisturized air.

4. Pressurized air.

5. Uninterrupted power.

ERLC

18. An operator must accept responsibility for

1 Beinq sure thai safety equipment will work when
ncedec*

2 ^-ellow operators.

3 Operator s own welfare

4. Seeinq that the supervisor complies with safety rc; j-
lattor

5 U*«>'ty's equipment.

19 Ammonia cylinders should be stored

1 Away from heat

2. In COOL dry locations

3. In the same room with chlonne.

4 With caps in place when not in use
3 With protection from direct sunlight.

20. True color is noriTially removed or at least decreased by

1. Chlonnation

2. Coagulation.

3. Filtration.

4. Ozonation

5 Sedimentation.

21 High levels of nitrate in a domestic water supply are
undesirable because of

1. Hardness.

2 Health threat due to «nfant methemoglobinema.

3. Laundry stains

4. Nitrate tastes.

5. Potential for stimulating excessive algae growth.

22. Primary contamrants which are considered to have
public health importance include

1. Lead.

2 Mercury.

3 Nitrate.

4 Odor.

5 Sulfate.

23 Turbidity is undesirable in drinking water because high
turbioity

1 Increases corrosivity.

2 Interferes with disinfection.

3 Interferes with micribiological determinations.

4 Prevents maintenance of an effective disinfectant.
5. Produces aesthetic problems

24 Possible approaches tor a utility to take to protect its
water supply from contamination include

1 Developing an extensive detection and monitoring
program.

2 Fencing off and patrolling reservoirs.

3 Having police lock up potential sources of contami-
nation

4. Isolating reservoirs that offer easy access to the
general public

5 Maintaining a low chlonne residual in the water.

25 Important uses of records include

1. Aiding operators in solving treatment and v/ater
quality problems.

2. Anticipating routine maintenance.

3. Providing data for future engineering de' gns

4. Satisfying legal requirements.

5. Showing that the treated water is acceptable to the
consumer

. c .586

566 Water Treatment

Short Answers

1 . How can the growth of iron bacteria in water systems be
controlled'?

2 Why should water being treated for iron and manganese
by ion exchange not contain any dissolved oxygen*?

3 Why should both underfeeding and overfeeding of flu-
oride compounds be avcded?

4. How would you dispose of empty fluoride chemical
containers'?

5 Why must water be stabilized after softening*?

6 Why should the same chemical hopper or feeder not be
used to feed both lime and alum at different times'?

7 Why are trihalomethanes in dnnkmg water of concern to
w^ter treatment plant operators'?

8 Where are samples collected for THM analyses'?

9 What are the common membrane demmeraliz.ng proc-
esses?

10 What causes "flux decline?"

1 1 - How can sludge be removed from sedimentation tanks'?

12. Why are source water stabilizing reservoirs helpful for
water treatment plants'?

13 Why should a qualified electrician perform most of the
necessary maintenance and repair of electrical equip-
menf?

14 Why are battery-powered lighting units considered bet-
ter than engine-driven power sou.ces?

15. Why must a suitable screen De installed on the intake
end of pump suction piping'?

16 What IS an analog instrumenf?

17 How are liquid levels in chemically-active liquids meas-
ured'?

18 how can pumps in a pump station be operated for
Similar lengths of time'?

19. What Items should be included in a utility's policy
statement on safety'?

20 Why do safety regulations prohibit the use of common
drains and sumps from chemical storage areas ^

21 What problems may be caused by iron in a domestic
water supply'?

22. What IS the mam source of trihalomethanes in dnnkmg
water'?

23. Why are nitrate concentrations above xhe national
standard considered an immediate health threaf?

24 Why are high levels of sulfate undesirable m dnnkinn
water?

25 Hovv can operators improve their technical knowledge
and skills'?

Problems

1 Determine the setting on a potassium permanganate
chemical feede. in pounds per day if the chemical dose
is 2.1 mg/L and the flow is 0.53 MGD.

2 Determine the setting on ^ potassium permanganate
chemical feeder in pounds per million gallons if the
chemical dose is 2 1 mg/L

3 A reaction basin 17 feet in diameter and 4 5 feet deep
treats a flow of 400,000 gallons per day. What is the
average detention time in minutes?

4 A flow of 0 3 MGD is to be treated with an 18 percent
solution of hydrofluosilicic acid (HgSiFg). The water to be
treated contains no fluoride and the desired fluoride
concentration is 1.1 mg/L. Assume the hydrofluosilicic
acid weighs 9.6 pounds per gallon Calculate the hydro-
fluosilicic acid feed rate m gal'ons per day.

5 A flow of 400 GPM is to be treated with a 2 4 percent
(0.2 pounds per gallon) solution of sodium fluonde
(NaO The water to be treated contains 0.5 mg/L of
fluonde ion and the desired fluonde ion concentration is
0 9 mg/L Calculate the sodium fluoride feed rate m
gallons per day. Assume the sodium fluoride has a
fluonde purity of 43.4 percent.

6 How many gallons of water with a hardness of 1 5 grains
per gallon may be treated with an ion exchange softener
with an exchange capacity of 24,000 kilograms?

7 How many hours will an ion exchange softening unit
operate when treating an average flow of 350 GPM'?
The unit is capable of softening 700,000 gallons of
water before requinng regeneration.

8 A water utility collected and analyzed eight samples
from a water distnbution system on the same day for
TTHMs. The results are shown below.

Sample No. 1 2 3 4 5 6 7 8

TTHM./ig//. 90 100 120 90 80 110 120 80

What was the average for the day'?

9 The results of the quarterly average TTHM measure-
ments for two years are given below Calculate the
running annual average of the four quarterly measure-
ments in micrograms per liter

Quarter i 2 3 4 1 2 3 4

Ave Quarterly
TTHM. ng/L

73 98 118 92 84 112 121 79

10 Estimate the ability of a reverse osmosis plant to reject
minerals by calculating the mineral rejection as a per-
cent The feedwater contains 1600 mg/L TDS and the
product w^ter is 145 mg/L.

1 1 Estimate the percent recovery of a reverse osmosis unit
with a 4-2-1 arrangement if the feed flow is 2.4 MGD and
the product flow is 2 0 MOD.

1 2 Calculate the pumping capacity of a pump in gallons per
minute if 14 minutes are required for the water level in a
;ank to drop 4.5 feet The tank is 1 1 feet in diameter.

13 Calculate the feed rate of a dry chemical feeder in
pounds per day if 2.8 pounds of chemical are caught in a
weighing tin during eight minutes

14. Calculate the threshold odor number (T.O.N.) for a
sample when the first detectable odor occurred when
the 35 mL sample was diluted to 200 mL (163 mL of
odor-free water was added to the 35 mL sampie).

ERIC

587

Final Exam 567

1 5 Determine the taste rating for a water by calculating the
arithmetic mean for the panel ratings given below

Tester No. 1 2 3 4 5 6 7

Rating 4 2 7 3 6 5 8

16 A small water system collected 12 samples dunng one
month After each sample was collected, 10 mL of
sample was placed in each of 5 fermentation tubes At
the end of the month, the results indicated that 3 out of a
total of 60 fermentation tubes were positive. What
percent of \he portions tested during the month were
positive*?