United States Office of Water EPA 570/9-88-006
Environmental Protection, (WH-550) September 1989
Agency
c/EPA Sanitary Survey
Reference Manual
-------
CREDITS
This manual was developed by the South Carolina Environmental
Training Center in partial fulfillment of a grant number T-901536-G1
from the U.S. Environmental Protection Agency Office of Drinking
Water. Some sections of this manual were taken from the Instruc-
tor's Technical Manual prepared by the Dynamac Corporation under an
earlier USEPA funded project.
Specific recognition is due to the following individuals who
were involved in the development and implementation of this training
course:
Project Director
Dr. William Engel, Director; South Carolina Environmental Training
Center; Sumter Area Technical College; Sumter, South Carolina
EPA Project Officer
Kenneth M. Hay.- Education/Training Specialist; Office of Drinking
Water, United States Environmental Protection Agency
Project Coordinator
Andrew A. Holtan, CET, President; A. Holtan and Associates;
Whiteford, Maryland
Instructors and Technical Advisors
Stephen G. Elder, Private Consultant; La Plata, Maryland
William Rowell, Director of Compliance and Enforcement; South
Carolina Department of Health and Environmental Control
Lenny Gold, President; Gold & Associates; Towson, Maryland
Instructional Development
Susan McMaster, Director of Staff and Instructional Development;
Sumter Area Technical College; Sumter, South Carolina
Media Development
Jann Jayroe, Media Specialist; Sumter Area Technical College;
Sumter, South Carolina
-------
Technical Advisors
Recognition is also due for the following individuals who assisted in selecting
the need-to-know technical information provided in the original manual. This was
accomplished with a great deal of discussion, compromise, and ultimate agreement
on the part of each of the individuals concerned with the development of this
document.
M. K. Batavia, Director, Water Supply, State o'f South Carolina
Bill Carpenter, Assistant Training Director, National Rural Water Association
Peter Karalekas, Water Supply Branch, USEPA Region I, Boston, Massachusetts
Ken Kerri, Professor of Civil Engineering, California State University at
Sacramento
Don Kuritz, Chief, Drinking Water Division, State of West Virginia
Don Moore, Office of Environmental Health, Indian Health Service - Phoenix
William Price, Chief, Technical Services and Training, Public Drinking Water
Program, State of Missouri
T. Jay Ray, Water Supply Branch, USEPA Region VI, Dallas, Texas
W. Clough Toppan, Manager, Drinking Water Program, State of Maine
Bob Williams, Water Supply Branch, USEPA Region II, New York, New York
ii
-------
PREFACE
This publication, Sanitary Survey Reference Manual, 1s a
reference for the Water Supply Systems Training Course on "How to
Conduct a Sanitary Survey".
A second reference entitled Sanj^ary Survey Instructors. Tech-
nlca.I_Manuai Is also available. Both references were previously
developed as United States Environmental Protection Agency projects
by the Conference of State Sanitary Engineers and the Dynamac Corpo-
ration, Rockville, Maryland. A third publication, In.struct.orls.
Guide, was organized to supplement the two aforementioned manuals.
The Ln§.tC!ic.toxl_§._Z§.
-------
TABLE OF CONTENTS
UNIT PAGE
UNIT 1 - THE SANITARY SURVEY 1-2
UNIT 2 - -WATER REGULATIONS 2-2
UNIT 3 - WATER SOURCES - 3-2
3a - Overview 3-2
3b - Wells 3-14
3c - Springs 3-24
3d - Surface Sources • 3-32
UNIT 4 - PUMPS 4-2
UNIT 5 - WATER TREATMENT ^ 5-2
UNIT 6 - GRAVITY STORAGE/HYDROPNEUMATIC TANKS 6-2
6a - Gravity Storage 6-2
6b - Hydropneumatic Tanks 6-10
UNIT 7 - DISTRIBUTION SYSTEMS/CROSS-CONNECTIONS 7-2
7a - Distribution Systems 7-2
7b - Cross-Connections 7-10
UNIT 8 - MONITORING/RECORDKEEPING/SAMPLING 8-2
8a - Monitoring 8-2
8b - Recordkeeping 8-12
8c - Sampling 8-14
UNIT 9 - MANAGEMENT/SAFETY 9-2
9a - Management 9-2
9b - Safety 9-6
UNIT 10 - SURVEYS/SANITARY SURVEY REPORT/FIELD EXERCISE 10-2
lOa - Surveys 10-2
lOb - Sanitary Survey Report 10-8
lOc - Field Exercise 10-14
UNIT 11 - COMMUNICATIONS/PUBLIC RELATIONS 11-2
UNIT 12 - TECHNICAL ASSISTANCE 12-2
APPENDIX 13-1
iv
-------
COUSSŁ NOTiS ?<.><_< uiNl
-------
UNIT 1
Unit 1: THE SANITARY SURVEY
Unit Summary
Evaluation of the:
SourceCs)
Operation and maintenance of facilities
and equipment
Distribution system'
Unit References
Manual of Individual Water Supply Systems
CPart O
Water Treatment Plant Operation Vol. I
CChapter 2)
Small Water System Operation & Maintenance
CChapter 2}
Water Distribution System Operation and
Maintenance CChapter 5)
1-2
-------
COURSE MOTES FOR UNIT i
-------
UNIT I
_ . - _ .. .. a i c. i.: n -
What Is a Sanitary Survey?
"Sanitary Survey" means an evaluation of operational and maintenance pro-
cedures, a review and inspection of the water sources, facilities and equip-
ment of a public water system for the purpose of producing and distributing
safe drinking water.
Sanitary Surveys may be Class I or Class II.
(i) A Class I Sanitary Survey is conducted once every three years
and must include a comprehensive evaluation of all water system
components, operational and maintenance procedures.
(II) A Class I Sanitary Survey is a limited survey which is conducted
on an as-needed basis and could include but not be limited to:
operational and maintenance inspections, complaint investigations,
follow-up inspections or the results of a compliance or enforce-
ment related action.
Why Conduct a Sanitary Survey?~"~~
Competent personnel must conduct sanitary surveys periodically to determine
whether the construction, equipment, facilities, operation, and maintenance of
the parts of a water supply system are adequate, effective, and efficient in
producing quantities of safe water for the consuming public, and whether the
water quality meets acceptable standards.
Who Conducts a Sanitary Survey?
Sanitary surveys are conducted by sanitary engineers, sanitarians, and techni-
cians who have experience, knowledge, and competence in the design, operation,
and maintenance of water supply systems. These personnel must be qualified to
assess problems using hydrological, hydraulic, mechanical, and other basic
engineering knowledge and be able to make sound, adequate, and economical
recommendati ons.
What Occurs During a Sanitary Survey?
The activities of a sanitary survey provide a comprehensive, accurate record of
the component parts of water systems, assess their operating conditions and
adequacy as a water system, and determine if past recommendations regarding the
system have been effectively implemented.
This program of Instruction presents the Information needed by the inspector to
effectively carry out the following activities:
Inspect and evaluate the water source.
Inspect and evaluate the intake structure.
. Inspect and evaluate the treatment/conditioning facilities.
. Inspect and evaluate the distribution system.
1-4
-------
COURSE NOTES FOS UNIT
-------
o Sample source and distribution water for bacteriological, physical,
chemical, and radiological properties, and (as required) perform
and evaluate field analyses.
o Review operation and maintenance practices.
o Review records,-files, maps, correspondence.
o Determine qualifications of engineering, sanitation, and ancillary
personnel; review management practices and personnel needs.
o Complete the survey report.
o Present sanitary survey data to operating personnel and (as
required) discuss onsite problems and provide recommendations.
o Notify the owner/operator, public, State regulatory agency, and EPA
of deficiencies (as required).
(Specific inspection and reporting information is included in the basic
material of the following units.)
Program Objective
For the remainder of this training program, we will be covering the
components of a typical water system:
o Source
o intake Structure
o Treatment
o Storage
o Distribution
We will be answering two questions about these components;
1. What conditions might cause sanitary risks in each of the
components?
2. How might these conditions be recognized?
1-6
-------
COURSE NOTES FOR UNIT
-------
A Sanitary Survey is:
00
A Review of:
• Source
• Facilities
• Equipment
• Operations & Maintenance
-------
COURSE NOTrio FOR
-------
Sanitary Survey
Class I every 3 years &
Comprehensive (All
components)
Class II As needed & limited
Figure 1-2
-------
COUHS'i
IS.'- i-'OR UNIT
-------
UNIT 2
Unit 2: WATER REGULATIONS
Unit Summary
Safe Drinking Water Act
~ National Interim Primary Drinking Water
Regulat ions
Unit References
National .Interim Primary Drinking Water
Regulat ions
Water Treatment Plant Operation Vol. I
CChapters 2, 8, and 11)
Small Water System Operation & Maintenance
i, Jnaocers i. 2. and 5}
Water Distribution System Operation and
Maintenance CChapters 1 and 6)
2-2
-------
COURSE NOTES FuR UNIT 2
-------
UNIT 2
Basic Material
In recognition of a decline in the quality of drinking water around the
Nation, Congress passed the Safe Drinking Water Act designed to ensure the
delivery of safe drinking water by public water systems and to protect
underground water sources from contamination.
The Act required the Environmental Protection Agency to establish primary
and secondary regulations limiting contaminants to a level where "no known
or anticipated adverse effects on the health of persons occur and which
allows an adequate margin of safety."
The National Interim Primary Drinking Water Regulations specify
requirements and procedures for controlling contaminants in public water
supplies.
Applicability
Although the Primary Regulations apply to all public water supply systems,
the regulations make a distinction between community and noncommunity
systems. Community systems generally supply drinking water to residential
and institutional users who might be exposed to dangerous levels of
contaminants for extended periods of time. Consequently, a wider range of
contaminants is controlled by the regulations. The regulations define a
"public water system" as a system for providing piped water to the public
for human consumption if such a system has at least 15 service connections
or regularly serves at least 25 people at least 60 days per year. The
term includes any collection, treatment, storage, and distribution
facilities under control of the system operator and used primarily in
connection with such a system, and any collection or pretreatment storage
facilities not under such control that are used primarily in connection
with such a system.
Some classes and types of regulated water systems are listed below.
Community Water Systems
Municipal systems and public water utilities
Mobile home parks
Condominiums
Residential institutions and schools, including hospitals, nursing
homes, homes for the aged, colleges
Housing developments, public and private
Multi family housing complexes (all varieties)
Noncommunity Water Systems (with separate water systems)
Motels-hotels-resort areas
areas
Schools (nonresident) i
Restaurant and other food Airports
service places
2-4
-------
•JO'UKSŁ MOTŁ5
UNIT 2
-------
Parks Medical care facilities
Recreation areas Shopping centers
Migrant labor and construction Office and commercial buildings
camps Public buildings and public
Children's and adult camps assembly facilities
Gasoline service stations Social and recreation clubs
Industries Swimming pools and beaches
Churches
Siting Requirements
The siting of a water system is of primary importance in ensuring safe
water. The National Interim Primary Drinking Water Regulations encourage
the avoidance of hazardous locations when constructing new or expanding
public water systems. Sites to be avoided are areas subject to
significant risks of:
o Earthquakes*
o Floods (100-year floodplain)
o Fire or other disasters that could cause a breakdown in the water
systems
o In many areas, California for example, it is impossible to
construct plants which are not subject to these hazards. In those
cases, good designing is even more critically important to
providing a continuous supply of water.
Maximum Contaminant Levels
The regulations include maximum contaminant levels for five properties of
drinking water.
o inorganic chemicals
o Organic chemicals
o Turbidity
o Microbiological contaminants
o Radiological contaminants
The specific maximum contaminant levels are provided in Tables 2-1 through
2-3. Each category has specific sampling and analytical requirements.
Water Purveyor Requirements
The water purveyor must report to the State agencys
o Results of all tests and analyses within the first 10 days
following the month in which the result is received, or within the
first 10 days following the end of the required monitoring period -
whichever is the shortest.
o Notice of failure to comply with any primary water regulations,
including monitoring, within 48 hours.
2-6
-------
COURSE NUIZ.5
-------
o Notify public when a community water system fails to comply with:
o An applicable maximum contaminant level
o An applicable testing procedure
o Scheduled corrections
o Required mo_nitoring
o Maintain the following records:
o Bacteriological analyses - for at least 5 years.
o Chemical analyses - for at least 10 years. Actual laboratory
reports may be kept, or data may be transferred to tabular
summaries, provided that the following information is included:
- Date, place, time of sampling; name of person collecting
- Identification of routine distribution system sample, check
samples, raw or process water samples, special purpose
samples; date of analysis
- Lab and person responsible for performing analysis
- Analytical method used
- Results of analysis
o Records of action taken to correct violations - for at least 3
years after last action was "taken with respect to a particular
violation.
o Copies of written reports, summaries, or communications relating
to sanitary surveys conducted by itself, private consultant, or
local, State or Federal agency - for at least 10 years after
completion of sanitary survey involved.
o Records concerning scheduling of improvements - not less than 5
years following expiration of scheduling time.
Responsibilities for Implementing NIPDWRs
Federal
As already noted, the Federal Government through the Environmental
Protection Agency has set the MCLs and Secondary MCLs for constituents to
ensure that no adverse health effects occur. If a State desires primary
enforcement authority (primacy), EPA will certify the program if the State
meets requirements. Annual evaluations will be performed to ensure the
quality of the State program.
Research, technical assistance, training programs, and funding are
provided States. EPA may take action if States fail to adopt or properly
implement the regulations.
2-8
-------
<.'. (.- u tf.3 z. 'A u Y Ł o r',- Ł u NI T
-------
State
Most States and territories have assumed primary enforcement responsi-
bility for enforcement of the regulations. SPA would retain program
responsibility only if a State is unable or unwilling to meet the minimum
requirements for primacy. To attain primacy under the Act, a State must
adopt standards at least as stringent as the Federal primacy standards.
States are free to adopt and enforce more stringent standards appropriate
to that State.
Additionally the States must:
o Maintain an inventory of public water systems.
o Have a systematic program for conducting sanitary surveys.
o Establish a program for certification of water testing laboratories
(unless testing is done by approved State laboratories).
o Assure that new or modified public water systems are capable of
compliance with State drinking water regulations.
o Establish procedures for enforcement.
o Authority to sue in court for violations
o Right to entry
o Authority to require suppliers to keep accurate records and make
appropriate reports to the State
o Establish and maintain recordkeeping and reporting of its
activities.
o if variances or exemptions are permitted, they must be under the
same conditions as granted under the Federal regulations.
o Adopt and implement an adequate plan for providing safe drinking
water under emergency conditions.
Water Utility Responsibilities
The responsibility of the water purveyor is to meet the primary standards
set by EPA, or the more stringent State standards.
These responsibilities include the treatment and monitoring of
bacteriological, chemical, and radiological contaminants; recordkeeping
and reporting of results to State agencies; and notification of any
noncompliance to consumers and the public.
The National Secondary Drinking Wa«-»r Regulations are designed to control
contaminants that affect the esthetic quality of drinking water. High
concentrations of these contaminants may have healtn as well as esthetic
implications. The federally set contaminant levels were set as guidelines
for State regulations provided in Table 2-4.
2-10
-------
COURSE NOTES
-------
Table 2-1 US PRIMARY AND SECONDARY DRINKING WATER REGULATIONS
Contaminant
Primary regulations*
Inorganics
Arsenic
Barium
Cadmium
Chromium
Fluoride
Lead
Mercury
Nitrate (as N)
Selenium
Silver
Microbials
Coliforms
Turbidity
Organics
2,4-D
Endrin
Lindane
Methoxychlor
Toxaphene
2,4,5-TPsilvex
Trihalomethanes (chloroform,
bromoform, bromodichlo-
romethane, dibromochloromethane)
Radionuclides
Beta particle and
photon radioactivity
Gross alpha particle
activity
Radium-226 + radium-228
Volatile organic chemicals
Benzene
Carbon tetrachloride
1,2-Dichloroethane
1,1-Dichloroethylene
l,l,]-Trichloroethane
/>ara-Dichlorobenzene
Trichloroethylene
Vinyl chloride
Secondary regulationsf
Chloride
Color
Copper
Corrosivity
Fluoride
Foaming agents
Iron
Manganese
Odor
pH
Sulfate
Total dissolved solids
Zinc
Unit
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ntu
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mrem
pCi/L
pCi/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
color units
mg/L
mg/L
mg/L
mg/L
mg/L
TON
mg/L
mg/L
mg/L
MCL
0.05
1.0
0.01
0.05
4.0
0.05
0.002
10.0
0.01
0.05
1/100 mL
1-5
0.1
0.0002
0.0004
0.1
0.005
0.01
0.10
4 (annual dose
equivalent)
15
5
0.005
0.005
0.005
0.007
0.20
0.075
0.005
0.002
:
"- 1
|
1
'Enforceable
Secondary
1 MCL
i
250
15
]
noncorrosivc
2
0.5
0.3
0.05
3
6.5-8.5
250
500
5
-------
-------
Table 2-2 Maximum Permissible Microbiological Contaminants (NIPDWR)
Coliform Method
Less than 20 20 or More
Per Month Samples per Month Samples per Month
Number of coliform bacteria shall not exceed;
Membrane filter 1/100 ml 4/100 ml in one
(100-ral portions) average density sample
4/100 ml in 5%
of samples
Coliform bacteria shall not be present in more than;
Multiple tube
fermentation
(10-ml portions)
10% of
portions
3 portions in one 3 portions in 5%
sample of samples
Coliform Method
Per Month
Less than 5 5 or More
Samples per Month Samples per Month
Coliform bacteria shall not be present in more than;
Multiple tube
fermentation
(100-ml portions)
60% of
portions
5 portions in more 5 portions in more
than one sample than 20% of
samples
Table 2-3 Maximum Permissible Radioactivity (NIPDWR)*
Contaminant
Maximum Contaminant Level
Picocurie per liter (pCi/1)
Natural
Combined Radiura-226 and Radium-228
Gross alpha particle activity, including
Radiura-226 but excluding Radon and
Uranium
Man-Made
Tritium (total body)
Strontium-90 (bone marrow)
Gross beta particle activity (applicable to
surface water sources)
15
20,000
8
50
*For full explanation refer to Part 141, National Interim Primary Drinking
Water Regulations.
2-14
-------
COURSE NOTES FOR UNIT 2
-------
Table 2-4. Special Monitoring Requirements Under National
Interim Primary Drinking Water Regulations.
Frequency
Contaminant Surface Ground
Sodium 1 sample annually 1 sample at least
every 3 years
Corrosivity 2 samples annually 1 sample annually
(1 mid summer)
(1 mid winter)
2-16
-------
-------
Table 2-5
CONTAMINANTS TO BE REGULATED UNDER THE SDWA AMENDMENTS OF 1986
Inorganics
Aluminum
Antimony
Arsenict
Asbestos
Bariumt
Beryllium
Cadmiumf
Chromiumt
Copper
Cyanide
Fluoridet
Leadt
Mercuryt
Molybdenum
Nickel
Nitratet
Seleniumt
Silverf
Sodium
Sulfate
Thallium
Vanadium
Zinc
Microbiology and turbidity
Giardia lamblia
Legionella
Standard plate count
Total coliformst
Turbidityt
Viruses
Organics
Acrylamide
Adipates
Alachlor
Aldicarb
Atrazine
Carbofuran
Chlordane
2,4,-Dt
Dalapon
Dibromochloropropane
Dibromomethane
1 ,2-Dichloropropane
Dinoseb
Organics, continued
Dioxin
Diquat
Endothall
Endrinf
Epichlorohydrin
Ethylene dibromide
Glyphosate
Hexachlorocyclopentadiene
Lindanef
Methoxychlort
Pentachlorophenol
Phthalates
Pichloram
Polychlorinated biphenyls
Polycyclic aromatic hydrocarbons
Simazine
2,4.5-TPt
Toluene
Toxaphenet
1,1.2-Trichloroethane
Vydate
Xylene
Radionuclides
Beta particle and photon activityt
Gross alpha particle activityt
Radium-226 and radium-228t
Radon
Uranium
Volatile organic chemicals
Benzenet
Carbon tetrachloridet
Chlorobenzene
cis-l,2,-Dichloroethylene
Dichlorobenzenet
1,2-Dichloroethanet
1,1-DichloroethjMenet
Methylene chloride
Tetrachloroethylene
trans-l ,2,-Dichloroethylene
Trichlorobenzene
1,1, 1 -Trichloroethanet
Trichloroethylenet
Vinyl chloride r
*Seven substitutions are permitted.
tAlready regulated
2-18
-------
'JNIT
-------
UNIT 3
Unit 3: WATER SOURCES
Unit 3a: Overview
Unit Summary
Hydrologic Cycle
Ground Water
Surface Water
Quality Water
Water Demands
Unit References
Manual of Instruction for Water Treatment
Plant Operations CChapter 2}
Manual of Individual Water Supply Systems
CChapter 1)
Water Treatment Plant Operation Vol. I
CChapter 2}
Small Water System Operation & Maintenance]
CChapters 1 and 2)
Manual of Water Utilities Operations
CChapter 1)
3-2
-------
COURSE NOTES r>jR UNIT
-------
UNIT 3
Basic Material
The two principal sources of water supplies are surface waters and ground
waters. Both originate from precipitation. Some of the precipitation
collects on the surface of the earth to form streams, lakes, and other
surface water.s. _Some seeps downward through the earth where it accumu-
lates in the pore spaces in the soils that overlay rock formations. The
seepage continues downward and laterally to fill the interconnecting
joints, cracks, solution channels, pore spaces, and other openings in
these rock formations below the soils. Ground water is not static and
tends to move slowly through the substrata, some of it reappearing at the
edge of streams and lakes or as springs and seepage areas. Energy from
the sun evaporates water from the earth, streams, lakes, and seas and
promotes transpiration of moisture from growing plants to form water vapor
in the atmosphere. The water vapor forms into clouds, which in turn
produce rain and snow to replenish the surface and ground waters. This
continuous process is called the hydrologic or water cycle; and by its
very nature, water is exposed to both natural and man-induced contamina-
tion.
Ground Water
Ground water is the principal source of water for small water supply sys-
tems. Ground water generally has a more consistent good bacterial quality
than surface water, having undergone considerable natural purification
through straining and prolonged storage. However, a number of areas have
suffered contamination of their ground water due to improper disposal of
their wastes. Generally it requires little (if any) treatment prior to
use, whereas surface waters invariably require rather sophisticated treat-
ment. Furthermore, ground waters are readily available in most areas of
the country in sufficient quantities to meet the needs of small water
systems.
Surface Water
Precipitation that does not enter the ground through infiltration or is
not returned to the atmosphere by evaporation flows over the ground
surface and is classified as direct runoff. Direct runoff is water that
moves over saturated or impermeable surfaces, and in stream channels or
other natural or artificial storage sites. The dry weather (base) flow of
streams is derived from ground water or snowmelt.
Runoff from ground surfaces may be collected in either natural or
artificial reservoirs. A portion of the water stored in surface
reservoirs is lost by evaporation and from infiltration to the ground
water table from the pond. Transpiration from vegetation in and adjacent
to ponds constitutes another means of water loss.
Because surface waters are exposed to potentially severe contamination by
both man and nature and because the quality of the water varies consider-
ably, a relatively high degree of treatment is required to ensure its
3-4
-------
-------
constant safety. The treatment is generally more sophisticated than with
ground waters and requires more diligent operation and maintenance and
more costs.
However, there are occasions when surface water is a source for a small
water supply system because of the poor quality or lack of local ground
water. Other factors being equal, impoundments such as natural lakes or
ponds, or reservoirs, are preferred over streams since the quality of the
water is usually less variable, reducing the extremes in quality.
Quality of Water
Precipitation in the form of rain, snow, hail, or sleet contains very few
impurities. Trace amounts of mineral matter, gases, and other substances
may be entrained as the precipitation forms and falls through the earth's
atmosphere; however, the precipitation has virtually no bacterial content.
Once precipitation reaches the earth's surface, many opportunities are
presented for the introduction of foreign substances into the water, which
may lower its quality to the point that it constitutes a health hazard or
impairs its usefulness.
Proximity of the water source to nearby sewers, waste disposal, construc-
tion projects, animal pasturing, chemically treated agricultural land, and
chemical- storage areas (such as salt or petroleum) increases the likeli-
hood of contamination. Other sources of contamination are completely
natural, such as the impact of high flood runoff, chemical composition of
soil above the rock (e.g., the presence of iron), or decomposition of or-
ganic matter.
Substances that alter the quality of water as it moves over or below the
surface of the earth may be classified as follows:
o Organic
o Inorganic
o Biological
o Radiological
Impurities in natural waters depend largely on the circumstances of the
source and its history. Water destined for an aquifer picks up impurities
as it seeps through soil and rock, including possible pollution. Pollution
sources may include leaking sanitary sewers, septic systems, waste disposal
sites, and accidental discharges. Uptake of minerals is common. The
natural straining action does remove some of the particulate matter and,
combined with a relatively long retention period in the ground, will often
aid in removing micro-organisms. This long retention time can, however,
create problems in that ground water once contaminated can be costly to
purge in terms of both time and money. Ground waters have a fairly stable
quality usually not highly affected by seasonal changes. Wells affected
by seasonal changes tend to be very shallow and subject to easy
contamination.
3-6
-------
COURS2
-------
Water Demands
The projected average daily demand is the quantity of water projected to
be used by a specific system or part of a system in an average day. This
is based upon experience from water meter readings in similar water
systems over an extended period of time and reflects the normal seasonal
and daily variations. For design purposes, it is usually determined by
estimating the population or units of housing or other units and
muliplying by an-average person or per unit water consumption derived from
past experience. Other water demand terms frequently relate to this basic
term. The average daily demand will be exceeded on many days so it is not
appropriate to design merely for the average. For this reason other terms
are used to express the probable greatest amount of water that may be used
in one day, or other period of time.
Table 3-1 provides a guide for estimating the average daily demand for
various types of establishments, in gallons per day per unit. The unit is
persons per day unless otherwise indicated. The values shown may vary
throughout the Nation, and the inspector is advised to review local
information on water systems serving similar size establishments.
The maximum daily demand is the greatest amount of water that a system
will use in one day. Experience with small residential water systems
suggests that the maximum day is 1.5 to 2 times the average day. However/
this ratio may not apply to other types of water systems. In general, the
smaller the water system, the greater the variation between the average
and the maximum day.
The maximum hourly demand is the greatest amount of water that will be
used in any hour during a day. Maximum hourly demand is sometimes
referred to as the peak hourly demand, although there will be short-term
peak demand rates lasting for several minutes that will exceed the maximum
hourly demand rate. Bach type of system exhibits it own maximum hourly
and short-term peak demands and the hours of peak occurrence will vary.
As an example, shopping centers usually experience hourly peaks in the
early afternoon while residential communities may experience two peak
hours, about 8:00 a.m. and 6:00 p.m. The maximum hourly demand is often
expressed as a ratio of the average daily demand, in gallons per minute.
Generally speaking, the smaller the system, the greater the maximum hourly
rate in respect to the average daily rate.
Peak demand is the maximum amount of water necessary to meet the peak
short-term demand rate that may occur several times during a day, but
usually during the peak-hour period. The instantaneous peak may last for
several minutes. The rate is particularly important in considering the
sizing of the storage tank in a hydropneuraatic system. The effective
storage capacity is usually designed to meet these short-term peaks. In
the absence of sufficient effective storage to meet extended peak demands,
the wells and pumps must be capable of meeting the peak demands. The-
smaller the system, the greater the ratio of the peak demand to the
average demand. Experience with small residential communities suggests
that the peak hourly demand may range from about 6 to 10 times the average
daily demand.
3-8
-------
FOP. UNI'
-------
Fire flow is the amount of water capacity that must be designed into a
water system for firefighting purposes. Fire flow is not included in the
definition of average daily and maximum daily demands and must be added if
fire protection is desired. Fire flows are usually expressed as gallons
per minute to fight a fire of a certain duration. Local fire underwriters
will provide specific requirements on request.
Sanitary Risks
1. What type of source (surface, ground or combination)?
There are specific risks for each type of source, which will be
covered in later sections of Unit 3.
2. What is the total design production capacity?
Comparison of this figure with present demand figures allows the
inspector to determine if there is adequate treatment capacity.
3. What is the present average daily production?
Comparison of this figure with values for other similar systems on a
per capita basis may point out problems within the system. An
evaluation of average daily production trends may indicate problems as
well. For example, if consumption is excessive or production trends
are increasing without an accompanying population or use increase,
leakage within the distribution system may be indicated.
4. What is the maximum daily production?
Comparison of this figure with design capacity allows determination of
adequacy of treatment capacity.
5. Does system have an "operational" master meter?
Without an operational and calibrated master meter, it is difficult
for the utility to accurately monitor production.
6. How many service connections are there?
This figure provides the inspector with an idea of the size of the
system; this means the total number of homes and businesses served by
the system, it should not include connections for vacant lots.
7. Are service connections metered?
This allows a water balance to be made. There is also a correlation
between metered service and water conservation. If the system is
metered, the per capita consumption is reduced.
A review of the system's records and operator responses should provide
answers to these questions.
3-10
-------
COURSE NuT-iS FOR UNI'
-------
Table 3-1, Guide for Estimating Average Daily water Requirements*
(Adapted from various sources for small water systems)
Type of Establishment (The unit is per person Average Daily Use (gpd)
unless otherwise stated) _
Airport (per passenger) 3-5
Assembly Halls (per seat) 2
Camps - Child, overnite, central facilities 40-50
- Construction 50
- Migrant labor 35-50
- Day type, no meals served 15
Churches (per member) 1
Cottages, season occupancy 50
Clubs - Residential 100
- Nonresidential 25
Factories, sanitary uses, per shift 15-35
Food Service - Restaurants 7-10
- With bars 9-12
- Fast food 2
Highway Rest Areas 5
Hotels (2 persons per room) 60
Institutions - Hospitals (per bed) 250-400
- Nursing Homes (per bed) 150-200
- Others 75-125
Office -Buildings 15-30
Laundries, self service (per customer) 50
Motels (per bed) 60
Parks - Day use (with flush toilets) 5
- Mobile homes (per unit) 200
- Travel trailers (per unit) 90-100
Picnic Areas (with flush toilets) 5-10
Residential Communities
- Multi-family (per bedroom) 120
- Rooming house and tourist
homes type (per bedroom) 120
- Single family type (per house) 400
Resort Motels and Hotels 75-100
Retail Stores (per toilet room) 400
Schools - Day, no showers or cafeteria 15
- Day, with cafeteria 20
- Day, with showers and cafeteria 25
- Residential types 75-100
Shopping Centers, per sq. ft. sales area 0.16
Swimming Pools and Beaches 10
Theaters - Drive-in (per car) 3-5
- Others (per seat) , 3
•The values listed in Table 3-1 are for normal water requirements and do
not include special needs or unusual conditions. State and local require-
ments may vary from those provided in this table. Additional allowance
should be made for frequent lawn watering, swimming pool maintenance,
industrial or commercial process water, cooling water, firefighting, and
other special uses.
3-12
-------
CO'JRir.
-------
UNIT 3b: Wells
Unit -Summary
Types and Characteristics
Sanitary Risk Factors
Surveying Wells
Unit References
Small Water Systems Serving the Public (Chapter 5)
Manual of Individual Water Supply Systems (Part ii]
Ground Water and Wells
Well Drilling Operations
Water Supply System Operation (Chapter 3)
Basic Material
To reach the. ground waters underlying the earth's surface, a well must be
constructed to penetrate the desired water-bearing strata. These
structures may be dug, driven, bored, jetted, or drilled, depending on the
geological formations through which they must pass and the depth to which
they must reach. Dug, driven, bored, and jetted wells are usually
confined to relatively soft soils overlaying rock and to shallow depths
normally less than 50 feet (15 meters). Wells using these sinking methods
should not be constructed for use as public water sources unless
specifically approved by the State regulatory agency. Drilled wells may
be used in both soft and hard soil and in rock and may be sunk to depths
of several hundred feet.
Drilled wells can be constructed in all instances where driven and jetted
wells might otherwise be used and in many areas where dug and bored wells
are constructed. The larger diameter of a drilled well, compared with a
driven or jetted well, permits use of larger pumping equipment that can
develop the full capacity of the aquifer.
There are various components of a well, many of which cannot be observed
by the sanitary surveyor. Some of the more important ones follow.
Well casing is installed in wells to prevent the collapse of the walls
of the bore hole, to exclude pollutants (either surface or subsurface)
from entering the water source, and to provide a column of stored
water and a housing for the pump mechanisms and pipes.
3-14
-------
COURSE NOTES FOR UNT
-------
Cement grout is used to fill the annular open space left around the
outside of the well casing during construction to prevent undesirable
water and contamination from entering the well.
Screens are installed at the intake point of the well to hold back
unstable aquifer material and permit free flow of water into the
well. The well screen should be of good quality (corrosion-resistant,
hydraulically efficient, and with good structural properties).
Well head covers or seals are used at the top of the casing or pipe
sleeve connections to prevent contaminated water or other material
from entering the well. A variety of covers and seals are available
to meet the variety of conditions encountered, but the principles and
the objective of excluding contamination are the same.
Pitless adapters are used to eliminate the need for a well pit.
Because of the flooding and pollution hazards involved, a well pit to
house the pumping equipment or to permit accessibility to the top of
the well is not recommended. Some States prohibit its use. These
units vary in design but generally include a special fitting designed
for mounting on the side of the well casing. The well discharge and
other piping are screw-threaded into the fitting, providing a tight
seal. The pitless system permits the connection of the well piping to
the casing underground below frost depth and, at the same time,
provides for good accessibility to the well casing for repairs without
excavation.
Sanitary Risks
1. Is the aquifer recharge area protected? What is the nature of the
recharge area?
The nature of activities on the recharge zone and whether or not they
are controlled can influence the quality of the water source. This
information can assist the inspector in the identification of the
potential source. The recharge area can be protected by means ranging
from ownership of the area by the utility with restricted access to
zoning laws prohibiting the use of subsurface waste disposal (septic
tanks). The owner/operator should know this information.
2. Is the site subject to flooding?
The introduction of surface waters into the well should be avoided.
Runoff in the immediate area should be drained away from the well
site. The well field should not be placed in a floodplain (100-year
flood). TO protect a well is easier than to clean an aquifer once it
is contaminated. Information on flooding and site drainage may be
obtained from the owner/operator, visual inspection, and flood stage
records. The exposed casing should terminate 18 inches above known
flood level.
3. Is the well located in the proximity of a potential source of
pollution?
3-16
-------
COURSE NOTEb K'R UNIT o
Your State regulatory agency should be consulted for its policy con-
cerning well location, particularly the minimum protective distances
between the well and sources of existing or potential pollution.
Table 3-2 is an example of typical minimum distances. These distances
are based on general experience and are not guarantees of freedom from
contamination. The water purveyor should provide even greater protec-
tion where possible. The table applies to properly constructed wells
with protective'casing set to a depth of at least 20 feet below ground
surface. Other types of wells will require special considerations.
Table 3-2 Sample Minimum Distances Between Wells and Pollution Sources
Source N Feet from Well Remarks
Watertight Sewers 50
Other Sewers 100 Consult the State
Septic Tanks 100 regulatory agency
Sewage Field, Bed or Pit 200 for special local
Animal Pens and Yards 200 requirements.
Source: Small Water Systems Serving the Public, Chapter 5.
4. What is the depth of the well?
The greater the depth of the aquifer utilized, the less chance of
surface contamination degrading the water quality. Deeper aquifers
generally have a more consistent quality of water.
5. What is the well drawdown?
Drawdown is the difference between static water levels and pumping
water levels. Measuring drawdown is important since changes in draw-
down can indicate problems in the aquifer (declining water levels) or
well (incrustation, sand) «, The operator should be able to provide this
information, if the operator is not measuring drawdown, he/she should
be encouraged to do so.
6. What is the depth of the casing?
The casing must be strong enough to resist the pressures exerted by
the surrounding materials and corrosion by soil and water environments.
The casing must be of the proper length to provide a channel from the
aquifer to the surface through unstable formations and through zones
of actual or potential contamination. The casing should extend above
potential levels of flooding and should be protected from flood water
contamination and damage. In unconsolidated soils, the casing should
extend at least 5 feet (1.5 meters) below the estimated maximum
3-18
-------
COURSE MOTHS FO^ UNIT 3
-------
expected drawdown level. In consolidated rock formations, the casing
should extend 5 feet (1.5 meters) into firm bed rock and sealed into
place. The operator should be able to provide this information.
7. What is the depth of grouting?
Specific grouting requirements of a well depend on the existing
surface conditions, especially the location of sources of pollution,
and the subsurface geologic and hydrologic conditions. To achieve
the desired protection against contamination, the annular space must
be sealed to whatever depth is necessary, but in no case less than 20
feet.
8. Does the casing extend at least 12 inches above the floor or ground?
This provides protection against surface runoff or drainage
problems. The 12 inches is recommended when there is no potential
for flooding.
9. Is the well properly sealed?
Well head covers or seals are used at the top of the casing or pipe
sleeve connections to prevent contaminated water or other material
from entering the well. A variety of covers and seals are available
to meet the variety of conditions encountered, but the principles and
the objective of excluding contamination are the same. Well covers
and pump platforms should be elevated above the adjacent finished
ground level and should be sloped to drain away from the well
casing. Well pits should not be used, since they may result in
contamination. Pitless adapters are used to eliminate the need for a
well pit. Because of the flooding and pollution hazards involved, a
well pit to house the pumping equipment or to permit accessibility to
the top of the well is not recommended. Some States prohibit its
use. A concrete slab around the well casing is not a completely
reliable seal, since burrowing animals and insects can undermine it
or it can be broken or cracked from frost heave or vehicles.
10. Does the well vent terminate 18 inches above ground/floor level or
above maximum flood level with return bend facing downward and
screened?
This is to keep water (from water cooled bearings for example), dust,
insects, and animals from entering the well casing.
11. Does the well have a suitable sampling cock?
This is important when trying to isolate sources of contamination in
a well field, if there is a well field and individual sample cocks
are not provided, it is difficult to determine if one or all wells
are the problem.
3-20
-------
-------
12. Are check valves, blowoff valves, and water meters maintained and
operated properly?
Valves should be maintained and operated to prevent contamination
from entering the well.
13. Is the upper., termination of the well protected?
The upper termination of the well should be either housed or fenced
to protect, it from vandalism and vehicle damage.
14. Is lightning protection provided?
Lightning surges can develop in powerlines during thunderstorms.
Such surges can damage pump motors, creating loss of water supply as
well as costly repairs. To protect against this, lightning arresters
can be provided where service lines are connected to service entrance
cables or at the motor control box. A multiground arrangement can be
provided that grounds the entire pump and well against damage.
15. Is pump intake located below maximum drawdown?
This prevents the pump from running dry as well as protects against
contamination in upper portions of water table from being pumped.
16. Are footr valves and/or check valves accessible for cleaning?
As with above-ground valves, these valves must be maintained in an
operating manner to prevent flow of undesirable water into the well.
3-22
-------
1'iU i Jl..
-------
UNIT 3c: Springs
Unit Summary
Spring Source Collection System Components
Sanitary Risks
Unit References
Small Water Systems Serving the Public
(Chapter 7)
Manual of Individual Water Supply Systems
(Part II)
Basic Material
To properly develop a spring supply, the natural flow of ground water must
be captured below the ground surface, and the method used must not
contaminate.the water. Springs are subject to contamination by wastewater
disposal systems, animal wastes, and surface drainage. Springs are also
susceptible to seasonal flow variations, and the yield may be reduced by
the pumping of nearby wells.
Springs may be gravity or artesian„ Gravity springs occur where the
water-bearing stratum overlays an impermeable stratum and outcrops to the
surface. They also occur where the land surface intersects the water
table. This type of spring is particularly sensitive to seasonal
fluctuations in ground water storage, and frequently dwindles or
disappears during dry periods. Gravity springs are characteristically
low-yielding sources, but when properly developed they may be satisfactory
for small water supply systems.
Artesian springs discharge from artesian aquifers. They may occur where
the confining formation over the artesian aquifer is ruptured by a fault
or where the aquifer outcrops at a lower elevation. Artesian springs are
usually more dependable than gravity springs, but they are particularly
sensitive to the pumping of wells developed in the same aquifer. As a
consequence, artesian springs may be dried up by nearby well pumping.
3-24
-------
Ji-i
-------
Important criteria for spring sources include selection of a spring with
acceptable water quality, development to the required quantity of water,
and sanitary protection of the spring collection system. The measures
taken to develop a spring must be tailored to the prevailing geological
conditions.
Spring Source Collection System
Spring flow is intercepted by a system of perforated pipes driven into the
water-bearing stratum or laid in gravel-packed trenches. The flow is
directed into a storage tank. As an alternative, a watertight concrete
collection chamber is constructed with openings in the bottom and/or a
side wall to intercept the flow. This chamber may also serve as the
storage tank. Where possible, the walls of the collection chamber should
extend to bedrock or the impervious stratum. The watertight walls should
extend 8 or more inches above ground to prevent entrance of surface
water. An overlapping (shoe-box) cover will prevent entrance of debris.
The tank is usually constructed in place with reinforced concrete to
intercept as much of the spring as possible. When a spring is located on
a hillside, the downhill wall and sides are extended downward to bedrock
or impervious soil to ensure that the structure will hold back water to
maintain the desired level in the chamber. Supplementary cutoff Walls of
concrete or impermeable clay may be used to assist in controlling the
water table in the vicinity of the tank. The lower portion of the uphill
wall of the tank must have an open construction to allow water to move in
freely while the aquifer material is held back. Backfilling with graded
gravel will aid in restricting movement of aquifer material.
The tank cover should be cast in place to ensure a good fit. The cover
should extend down over the top edge of the tank at least 2 inches, should
be heavy enough to prevent dislodging by children, and should be lockable.
A drain pipe with an exterior valve should be placed close to a wall of
the tank at the floor level to permit draining. The end of the pipe
should extend far enough to allow free discharge to the ground surface,
away from the tank. The discharge end of the pipe should be screened to
prevent nesting by animals and insects.
The overflow is usally placed slightly below the maximum water-level
elevation. The overflow should have a free discharge to a drain apron of
rock to prevent soil erosion at the point of overflow and should be
screened.
The supply intake should be located about 6 inches above the floor and
should be screened. Care should be taken to ensure good bond between
pipes and the concrete structure.
Infiltration Galleries
Recreational or other developments located in the mountains may have
access to a head water mountain stream where the watershed is generally
heavily forested and uninhabited by man. However, after periods of heavy
rainfall or spring thaws, debris and turbidity may cause problems at the
3-26
-------
COURSE NuFIi r'.»R UNIT
-------
water intake and will materially increase the required degree of
treatment. If the conditions are suitable, this problem can be avoided by
constructing the intake in an underground chamber (infiltration gallery)
along the shore of the stream or lake.
Galleries may be considered where porous soil formations adjoin a stream
or lake so that the water can be intercepted undergound to take advantage
of natural filtration. Any gallery access structures should be located
above the level of severe flooding.
A typical installation generally involves the construction of an
underdrained, sand filter trench located parallel to the stream bed and
about 10 feet from the high water mark. The sand filter is usually
located in a trench with a minimum width of 30 inches and a depth of about
10 feet, sufficient to intercept the water table. At the bottom of the
trench, perforated or open joint tile is laid in a bed of gravel about 12
inches in thickness, with about 4 inches of graded gravel located over the
tile to support the sand. The embedded tile is then covered with clean,
coarse sand to a minimum depth of 24 inches, and the remainder of the
trench backfilled with fairly impervious material. The collection tile
drains to a watertight, concrete chamber from which water may flow to the
distribution system by gravity or pump, whichever is appropriate.
Chlorination is generally necessary and may be done in the chamber or at
another place, but prior to any use.
Where soil formations adjoining a stream are unfavorable for the location
of an infiltration gallery, the debris and turbidity that are occasionally
encountered in a mountain stream may be controlled by constructing a
modified infiltration gallery in the stream bed.
If a natural pool is not available in the stream bed, a dam is usually
constructed across the stream to form a pool. The filter is installed in
the pool by laying perforated pipe in a bed of graded gravel, which is
then covered by at least 24 inches of clean, coarse sand. About 24 inches
of freeboard should be allowed between the surface of the sand and the
surface water level. The collection lines may terminate in a watertight,
concrete basin located adjacent to the upstream face of the dam from where
the water is diverted to chlorination facilities.
Sanitary Risks
1. Is the recharge area protected?
2. What is the nature of the recharge area?
3. Is the site subject to flooding?
The rationale for the above questions is the same as that for wells.
4. Is the collection chamber properly constructed?
The collection chamber should be watertight to prevent the inflow of
undesirable water. The tank cover should be impervious and lockable.
The drain should have an exterior valve and the exterior end
screened. The overflow should have a free discharge to a drain apron
to prevent soil erosion. This information may be obtained by
inspection of the collection chamber.
3-28
-------
UNI'
-------
5. Is the supply intake adequate?
The supply intake should be located 6 inches above the chamber floor
and screened. This location reduces the withdrawal of the sludge that
may build up in the chamber.
6. Is the site adequately protected?
The following precautionary measures will help ensure spring water of
consistently high quality:
o Diversion of surface drainage from the site. A surface drainage
ditch should be located uphill from the source to intercept
surface water runoff and carry it away from the source. Springs
in close proximity to agriculturally developed land treated by
pesticides and herbicides may be particularly susceptible to
contamination.
o Protection from stray livestock and from tampering by means of
site fencing, locked covers, and Warning signs.
7. What conditions cause changes to quality of the water?
A marked increase in turbidity or flow after a rainstorm is a good
indication that surface runoff is reaching the spring.
3-30
-------
COURSE
'iS FOR UNIT
-------
UNIT 3d: Surface Sources
Unit Summary
Types and Characteristics
Sanitary Risks
Unit References
Small Water Systems Serving the Public
(Chapter 8)
Manual of Individual Water Supply Systems
(Part III)
Water Treatment Plant Operation
(Volume 1, Chapters 2 and 3)
Water Supply System Operation (Chapter 2)
Basic Material
Surface water sources used for small water supply systems require consid-
eration of additional factors not usually associated with ground water
sources. When small streams, open ponds, lakes, or open reservoirs must
be used as sources of water supply, the danger of contamination and of the
consequent spread of intestinal diseases such as typhoid fever and dysen-
tery is generally increased. Clear water is not always safe, and the old
saying that running water "purifies itself" to drinking water quality
within a stated distance is false.
The physical, chemical, and bacteriological contamination of surface water
makes it necessary to regard such sources of supply as unsafe for domestic
use unless reliable treatment, including filtration and disinfection, is
provided. The treatment of surface water to ensure a constant, safe
supply requires diligent attention to operation and maintenance by the
owner of the system. Principal sources of surface water that may be
developed are controlled catchments, ponds or lakes, surface streams, and
irrigation canals. Except for irrigation canals, where discharges are
dependent on irrigation activity, these sources derive water from direct
precipitation over the drainage area.
3-32
-------
-------
Controlled Catchments
In some areas, ground water is so inaccessible or so highly mineralized
that it is not satisfactory for domestic use. In these cases, the use of
controlled catchments and cisterns may be necessary. A properly located
and constructed controlled catchment and cistern, augmented with a
satisfactory .filtration unit and adequate disinfection facilities, will
provide a safe water. However, cisterns should be utilized only when no
other source is available.
Ponds/Lakes/Reservoirs
The development of a pond as a supply source involves: (1) selecting a
watershed that permits only water of the highest quality to enter the
pond, (2) using the best water collected in the pond, (3) filtering the
water to remove turbidity and reduce bacteria, (4) disinfecting filtered
water, (5) properly storing the treated water, and (6) properly
maintaining the entire water system.
The value of a pond or lake as a source is its ability to store water
during wet periods for use during periods of little or no rainfall. A
pond should be capable of storing a minimum of one year's supply of
water. It must be of sufficient capacity to meet water supply demands
during periods of low rainfall with an additional allowance for seepage
and evaporation losses. The drainage area (watershed) should be large
enough to catch sufficient water to fill the pond, or lake during wet
seasons of the year.
To minimize the possibility of chance contamination, the watershed should
be:
o Clean, preferably grassed
o Free from barns, septic tanks, privies, and soil-absorption fields
o Protected against erosion and drainage from livestock areas
o Fenced
The pond should be:
o Not less than 8 feet deep at the deepest point
o Large enough to store at least one year's supply
o Designed to have the maximum possible water
storage area over 3 feet in depth
o Fenced
o Free of weeds, algae, and floating debris
In many instances, pond development requires the construction of an
embankment with an overflow or spillway.
Streams and Rivers
Streams receiving runoff from large uncontrolled watersheds may be the
only source of water supply. The physical, chemical, and bacteriological
3-34
-------
COURSE NOTES FuR UNIT
-------
quality of surface water varies and may impose unusually or abnormally
high loads on the treatment facilities.
Stream intakes should be located upstream from wastewater discharges,
•storm drains, or other sources of contamination. The water should be
pumped when the silt load is low. A low-water stage usually means that
the temperature of the water is higher than normal and the water is of
poor chemical quality. Maximum silt loads, however, occur during maximum
runoff. High-water stages shortly after storms are usually the most
favorable for diverting or pumping water to storage. These conditions
vary and should be determined for the particular stream.
Irrigation Canals
If properly treated, irrigation water may be used as a source of domestic
water supply. Water obtained from irrigation canals should be treated the
same as water from other surface water sources.
Water from irrigation canals may contain large concentrations of
undesirable chemicals, including pesticides, herbicides,' and fertilizer.
Periodic chemical analysis should be made.
Sanitary Risks
1. What is the nature of the watershed?
Industrial Agricultural Forest Residential
As previously noted, the activities on the watershed will impact on
the water quality of the runoff. The potential for spills from
industrial activities, herbicides and pesticides from agricultural
land uses, organics from plant decay, and animal-borne diseases are a
few problems that may be indicated by land use on the watershed.
2. What is the size of the owned/protected area of the watershed?
To reduce the extent of contamination of the watershed, many utilities
have chosen to purchase a portion of it. Another method is to
restrict activities through zoning restrictions and ordinances.
3. How is the watershed controlled?
This question allows the inspector to evaluate the effectiveness of
watershed control measures. Ownership with restricted access is the
most stringent measure but it is also the most costly. If ordinances
are used, the inspector may wish to know how they are enforced.
3-36
-------
-------
4. Has management had a watershed survey performed?
If the utility has had a watershed survey conducted, many of the
above questions may be answered by referring to it. The fact that a
utility has conducted such a survey would indicate a concern on its
part for the protection of the supply.
5. Is there an emergency spill response plan?
Some industries (e.g., petroleum) are required to have emergency
spill plans. Potential spill sites should be identified by the
utility and contingency plans developed in the case of a spill.
However, because a plan is only paper, the necessary equipment and
personnel must be identified and coordination between respective
agencies (fire, police, water utility) worked out prior to any
emergency.
6. Is the source adequate in quantity?
To answer this question, the inspector should determine if the source
is adequate for present as well as future demands. The source should
be able to continuously meet the demands of the water system.
Decreasing trends in quantity are also important to note. Operation
records should provide this information.
7. Is the source adequate in quality?
A review of monitoring records should reveal this answer. As with
quantity, any trends of decreasing quality should be noted.
8. Is there any treatment provided in the reservoir?
The addition of any chemicals to the reservoir should be noted.
Particular concern is assuring that only approved chemicals be
utilized and that they be properly applied.
9. Is the area around the intake restricted for a radius of 200 feet?
Restriction of contact sports (e.g., swimming and water skiing) and
use of powerboats in the vicinity of the intake is important. This
will reduce the coliforra and organic pollution of the intake water.
10. Are there any sources of pollution in the proximity of the intakes?
Sources of pollution such as wastewater discharges, feedlots,
marinas, and boat launching ramps should be identified. If the use
of the reservoir is not restricted, the impact of activities should
be minimized as much as possible by keeping them away from the
intakes.
3-38
-------
COURSE
-------
11. Are multiple intakes located at different levels utilized?
Because of fluctuations of the water surface elevation and the
variability of water quality with depth, it is necessary that intakes
be provided at different depths. Seasonal turnover of the reservoir,
algal blooms, and thermal stratification can cause water quality
problems. This applies to deep reservoirs, streams, and shallow
reservoirs not subject to stratification commonly utilized at
single-level intakes.
12. Is the highest quality water being drawn?
The operator should be performing monitoring tests to determine the
water quality at the various depths in order to draw the best quality
water. The operator should be questioned as to how the intake level
is selected, what tests are accomplished, and at what frequency.
Suggested tests are dissolved oxygen, metals, and nitrogen values.
13. How often are intakes inspected?
As with all components, maintenance must be periodically performed on
the intake structure. Removal of debris and inspection of intake
screen integrity will prevent damage to piping valves and pumps.
This is particularly important during winter months due to the danger
of sheet and frazzle ice buildup.
14. What conditions cause fluctuations in water quality?
Conditions such as stratification, algal blooms, ice formation,
on-shore winds, and changing currents may create adverse changes to
water quality. Conditions creating such problems should be noted as
well as what measures are being taken to mitigate them.
15. Has the dam been inspected for safety (if applicable)?
Dams should be routinely inspected to avoid conditions that may
endanger their integrity. Many States require that such inspections
be performed. However, if not required, operators should be
encouraged to look for such things as erosion, sinkholes, burrowing
animals, and trees growing in the dam face.
3-40
-------
-------
: - „->: r ------T- -^-^^-^^ymimM.^^^^:
^:-^-L _-1«"_-v-: :• I'jif.J^-i^ d~ ^Sfel:|^fc.;
I I I
EVAPORATION
I 1 I
Hydrologic Cycle
-------
COURSE NU7ES ruK Ui-iIT
-------
at
n
n>
i
NJ
UNCONSOLIOATEO AQUIFER
Aquifers
-------
-------
Static Water Level
Screen
Figure 3-3
-------
:OURSE
•5 FOR UNIT
-------
Typical Site
Plan
Figure 3-4
-------
-------
c
n
(D
U)
I
(Jl
Emergency
Generator
L=>
c_r
Chlorinator
Septid
Tank '
t
-------
COURSE NOTES FOR UNIT 3
-------
OQ
C
H
n>
OJ
o\
-* f-
c_r
-------
COURSE
-------
•s
Surface Water
Diversion Ditch -
Lock
f. — Maximum Water Level
'. ' :'•. Watpr-Bearlng GravelI".
»' • HEVATION .
-------
COURSE NOTJŁŁ rOR UNIT
-------
H
(D
CO
00
Infiltration Gallery
-------
COURS2
-------
H
n>
Collection
//////
10 ft.
Gravel
,—i
i ^. ""lyy *ji* ik*y /.'i rf'j i
ft">IJJ o b
V 'Ac."-V'Vxv
-'xrX >.~'-iyj;
O O O O
ooo
-^- Discharge Line
Water Level
O O 0 O
oooo
Submersible Pump
Infiltration Gallery
-------
-------
00
u>
I
Water-Bearing'Sand' '
TO STORAGE
Identify Deficiencies
-------
COURoŁ MUTES FOR UNIT
-------
OQ
(B
OJ
. Minhol* Covw
\f
'
t
1
1
•
r.i
t
p
^- Screened
S Or*m
iuwo
Ouwn S|ioul 'J
tioai Haul * jL
^J ~ r-yv
Iril l|»
3
Rool
Wither
Receive) fir It || f *uc«l
Kunofl fiomRoolli -,1
.'• » '" ^
-------
COURSE NUTŁS FOK UNIT
-------
H
ID
t— »
NJ
-------
COURSE NOTES FOR UNIT 4
-------
UNIT 4
Unit 4: PUMPS
Unit Summary
Types and Characteristics
— Sanitary Risks
Unit References
Manual of Individual Water Supply Systems
CPart V)
Manual of Water Utility Operations
CChapter 13}
Manual of Instruction for Water Treatment
Plant Operators CChapter 19)
Water Treatment Plant Operation Vol. I
CChapter 11)
Small Water System Operation & Maintenance
CChapter 3)
Water Distribution System Operation &
Maintenance CChapters 2 and 5)
Basic Material
Types of Pumps~
Positive Displacement Pumps. The positive displacement pump force;
or displaces the water through a pumping mechanism. There are
several types: reciprocating pumps, helical or spiral rotor, rege
erative turbine pumps, and diaphragm pumps.
Centrifugal Pumps. Centrifugal pumps contain a rotating impeller
mounted on a shaft turned by the power source. The rotating Impel
ler increases the velocity of the water and discharges it into a
surrounding casing shaped to slow down the flow of the water and j
convert the velocity to pressure. This decrease of the flow furths
Increases the pressure.
Jet CE lector) Pumps. Jet pumps are actually combined centrifugal
and ejector pumps. A portion of the discharged water from the
centrifugal pump la diverted through a nozzle and venture tube, ft
pressure zone lower than that of the surrounding area exists in thg
venturl tube; therefore, water from the source Cwell) flows Into
this area of reduced pressure. The velocity of the water from the
nozzle pushes It through the pipe toward the surface where the
centrifugal pump can lift It by suction. The centrifugal pump then
forces it into the distribution system.
Rotary Pumps. In the rotary pumps there are two cams or gears thai
mesh together and rotate In opposite directions. The gear teeth oi|
cams fit closely to the casing so that the water will be drawn up
the suction pipe and forced into the discharge pipe. Such pumps
4-2
-------
COURSE NOTES FOR UNIT
-------
require no valves and are self-priming. They are positive dlspl
ment . They can be operated at high speeds and so obtain large
capacity with small size. They have the disadvantage of showing
considerable slip. Water containing grit is especially
them .
Sanitary Risks
1. What is the number Cincluding reserves} and location of
At least two pumping units should be provided Cfor both chei
cal feed and water applications of pumps}. Pumps may be uss
for a variety of reasons with'in the system: raw .water, che«
cal feed, finished water, and solids movement. The type of
pump is important to assure proper application. For examph
positive displacement-type solution pumps should be used to
feed liquid chemicals but not to feed chemical slurries. Th
operator and a review of plant schematics can provide this
Informat ion.
2. What is the rated capacity of the pumps?
Pumps should have ample capacity to supply the peak, demands
without dangerous overload. The Inspector should also ask
when the pump was last rated. This Is particularly importan
when the -pumping time is used to estimate water production.
The pump may have been rated 10 years ago for 200 gpm but dll
to changes in the pump and system Is presently only pumping
125 gpm. The inspector should also note If the pump is
metered. This can help the operator detect changes in the
system and take corrective action before a serious problem
develops.
3. What Is the condition of the equipment?
The pumps should be operable! No benefit Is provided the.
system when only one of its three raw water pumps Is func-
tional. The Inspector should note the state of repair-
Although packing gland seals require a constant drip of wate
it should not be an excessive spray. The pumps should not b
overgreased of overolled. Excessive noise and vibration, pa
tlcularly of centrifugal pumps, would Indicate problems. Ito
the condition of the room; If It's dirty, operation can-not
satisfactory. Dirt will get Into the lubricants and shorten
the life of the- bearings.
A. What type of lubricant Is used?
In the case of well pumps, this Is particularly Important
since oil contamination of the aquifer Is possible from lBPr
erly maintained submersible pumps. In the case of water-
lubricated pumps, the possibility of cross-connection exist?
4-4
-------
COURSE NOTES FOR UNIT
-------
5. Is the emergency power/backup system provided?
Emergency power is necessary for continuous operation of the
water system. This may be provided by an auxiliary generator
or by directly connected engines. The Inspector should note
how emergency power Is provided, how frequently It is tested,
and whether there is automatic or manual switchover. The
inspector should also be concerned with the number of primary
power failures. Availability of replacement pumps, motors, an]
critical parts should also be evaluated.
6. Are all electro/mechanical rotating equipment provided with
protective guards?
The Inspector should not only be concerned with the sanitary
aspects of the equipment but safety as well. The inspector
should check to see that belts, gears, rotating shafts, and
electrical wiring are properly shielded to prevent injury.
7. Are controls functioning properly and adequately protected?
All controls should be functional. Jerry-rigging of controls
presents both an electrical hazard and risk of failure of the
pump.
8. Are underground compartments and suction wells waterproof?
Pump stations should be waterproofed to prevent flooding of thj
pump room. The suction wells should be protected to prevent
entrance of undesirable water Into the compartment either
through the walls or surface water-
9. Are permanently mounted ladders sound and firmly anchored?
As previously stated, the Inspector should be concerned with
safety. This concern is not only for the operator's sake, but
for the inspector's own preservation. The inspector should
follow safety procedures and Inform the operator of unsafe
conditions or acts Ce.g., entering a confined space that la
not properly ventilated).
10. Is the facility properly protected?
The site should be properly protected against fire, flood,
vandalism, and other hazards. The location should be a mini nun
of one. foot above the highest flood level. Runoff should drain!
away from the pumping station. Pumping facilities should be
protected against vandalism and unauthorized entry by animals
or people.
4-6
-------
COURSE NOTES FOR UNIT 4
-------
Table 4-1,. Types and Characteristics of Pumps
.p-
00
Ty)«:
] hv-p will.
WL-II....
'iiM iw
lypu
line
7 ll-l-p u:l I
a) Vurlkal
•Ju(t luifcii
(mil ial •>Ł<.•)
Pr-Klic.,1
Stng
U.'|itl)
22-25 ft.
Up in 601) ft .
10-20 ft.
28 ft.
40- «U ft.
Oaual
Prevent
lk»la
100-200 ft.
Up la 600 ft.
•Lave cylinder.
100-150 ft.
100-200 ft.
100-HOO ft.
Advantages
a h»iti« .ctlo,,.
• Diacharge againaf variable
henda.
• Piiifia voter utitainlng
laitl aid (ill.
• Eapecially alaptod Ui lov
capacity mil high lift*.
• awuth, even flow.
• Pt«|>a utter containing
•uul ail) ailt.
• Pieaiurc on ay a ten ia even
aid free frua alock.
• llaially reli4>l« aiil good
aervica life.
******
a Sam IH atraiglit ccitri-
fugnl except nU aiilaSle
(or p»aj>ing water tuiilain-
ing MI«! or ailt.
• 11 wy ant w:lf |«inlnK.
******
• Sam: aa oliallow u:ll
turliine.
• All elitctrical cnu^iiwita
aiti i*'ii!aalble, Jxivn
glolkl.
Dinadvanlagea
• Pulaatbv diacliarge.
• IMtject lo vibrat ion anl
noiae.
• Haintenance co«t uy bu
higli.
• Hoy cauad du-atructive
preaaure if operated
againat cloand valve.
• loout |riuu c.uily.
• Efficiency dupunla ui
operat iitt iiwler dcaiun
ItfAda ttil uptittl.
• San; u ilruiglit centri-
fugal exce|>t luimaim
priming tunily.
• Efficiency dfjionla ai
operating itider du'aign
liead «ikl aptfui.
• Hcqiitrea atraigfit well
large enun^i for turbine
bowla aitl lioiwii^.
• UaVication «ikl alignuuu.
of Arft «itfc.l.
RuurVa
• Beat auilol fur capoci-
t iea of 5~~25 givi ^ttiiut
•odurate to high lieula.
• Adapt <*> It to haiki
operation. (
• Can be inatal'led in wry
aiull dimeter «jllo (2"
caaing).
• PL»|> wnt be aet directly
(Ner welt (duty uul In).
• Very ef ficieit piinp fur
capacitlw iliovu dU n|iu
anJ bea>la up to «iuul
150 ft.
• RuJuctlon in preauire
with increwed cajuclty
nd. aa aeuuiu aa vtiaiglit
ceicrifugwl.
-------
COURSE NOTES FOR UNIT 4
-------
Table 4-1 (Continued)
Type of Puwp
Centrifugal (cant.)
b) Sulaenibla
turbine
Guilt Utage)
Jet:
1 Shallow tell
2 Deep wall
totary;
1 Shallow well
(gear type)
(helical rotary
type)
Practical
Suction
Lift
PUJJ> anl
rotor
•ubnerged.
IV20 ft.
below
ejector.
15-20 ft.
below
ejector.
22 ft.
Usually
submerged.
Ifcual
Well-Pu«pin*
Depth
50-W) ft.
Up to IS- 20
ft. below
ejector.
25-120 ft.
200 ft. max.
22 ft.
50-500 ft.
Dual
Preaaure
Ifeada
50-400 ft.
80-150 ft.
80-150 ft.
50-250 ft
100-5(10 ft.
Advantage*
• Sane on ahallow well
turbine.
• Eoay to front-proof.
• Short runp ahaft to antor.
• Qjiet operation.
• Well atraightneaa not
critical.
• High capacity at low
heftJa.
• Siople in operation.
• Doe* not have to he
installed over tie well.
• Ho onving parta in thia
well.
• Bone aa ahallow well jet.
• Well atraightnea* not
critkal.
• Diadiarge cunatant inter
variable heada.
• Efficient operation.
• Sane aa ahatlow well
rotary.
• Only aie rawing ruap
device in well.
,
DiaadvaiAagea
• Abraaini fro* sard.
• Repair to mtor or p»f>
requirea |ullii% frua
well.
• Sealing of electrical
eif dpneit froa water
vapor critical.
• Miraaion from aanl.
• Capacity rediicea aa lift
increanea .
• Air in auction or return
line will atop pinping.
• SaiK aa dial low wel 1 jet .
• Umer efficiency,
especially at greater
lifta.
water cuitaiia aaid or
•ilt.
• Wear of geara reduce*
efficlenry.
• Same aa ahallow well
rotary except no gear
wear.
Remarks
• 3500 RFMnxfela, Uule
popular lucatiae of
analler diajoL-tera or
greater capaLitiea, are
•ore vulnerable u> uu.ir
ard failure trim eaiit ant
otlier causca.
• Tie aoDunt of water
returned to ejector with
increased lift - 50t of
total water pun|cd at
50-ft. lift anl 7S at
100-ft. lift.
• A cullcaa rubber utator
increaica life of |»«n'.
Flexible drive ctxipling
haa been ut* |oii
-------
COURSE NOTES FOR UNIT 5
-------
UNIT 5
UNIT 5: WATER TREATMENT
Unit Summary
Treatment Processes
Sanitary Risks
Unit References
Small Water Supplies Serving the Public
(Chapters 9, 10)
Manual of Instruction for Water Treatment
Plant Operators (Chapters 5-15)
Manual of Water Utility Operations
(Chapters 7-11)
Water Treatment Plant Operations
(Volume 1, Chapters 4-9 and 11)
Water Supply System Operation (Chapter 4)
Basic Material
The purpose of water treatment is to condition, modify or remove
undesirable impurities to provide a water that is safe,, palatable, and
acceptable to consumers. National standards (specified in the NIPDWR with
maximum contaminant levels) for some of the impurities that are considered
important to the health of consumers are set under the Federal Safe
Drinking Water Act. If these contaminants are present in excess of the
established limits, the water must be treated to reduce the levels. Some
impurities that affect the esthetic qualities of the water are listed in
SDWR as guidelines. Treatment or modification of the water to achieve
these desirable levels is highly recommended.
Some of the common treatment processes and their purposes are:
Pretreatment - generally for removal of taste and odors.
Coagulation/yiocculation - treatment with certain chemicals for
collecting nonsettleable particles into larger or other fine-grained
materials to remove particulate matter too light or too finely
divided for removal by sedimentation.
Sedimentation - removal of suspended matter.
5-2
-------
COURSE NOTES FOR UNIT 5
-------
Filtration - filtering through sand, anthracite/ or other fine-
grained materials to remove particulate matter too light or too
finely divided for removal by sedimentation.
Disinfection - destroying pathogenic organisms with chlorine, certain
chlorine compounds, or other means.
For specific information on the treatment process, the suggested
references should be consulted. It is suggested that the inspector be
familiar with:
Coagulation: Aluminum Sulfate and Iron Salts
Chlorination: Gas and Hypochlorite
Filtration: Rapid Sand
Pressure
Diatomacepus Earth
Ion Exchange
Lime Softening
Sedimentation
Taste .and Odor Control
Corrosion Control
Sanitary Risks
Prechlorination/Chemical Pretreatment
Although treatment for taste and odors can be performed at several
locations in the treatment process, frequently it is conducted as a
pretreatment. This allows the time in the pipe from the intake to the
plant to be used as contact time. Chemicals commonly used are chlorine,
activated carbon, potassium permanganate, ozone, and chlorine dioxide.
There are other pretreatment processes such as aeration, presedimentation,
and screening that may be encountered, but the following questions deal
with processes utilizing chemical addition.
1. What chemical is used?
The inspector should determine what chemicals are utilized, if they
are approved, and if they are being properly applied.
2. What is the amount used?
The amount utilized should be based on testing. The inspector should
inquire as to how the dosage is determined and how frequently. In
some cases the inspector will find that the dosage has been based on
tests conducted in the distant past and has remained the same even
though conditions have changed.
3* For prechlorination, has total trihalomethanes (TTHM) been evaluated?
Although TTHM control is not required for systems serving a
population of less than 10,000, the inspector should determine if Che
operator is aware of their impact and caudes. The dosage and/or
application point may be changed to reduce their levels.
5-4
-------
COURSE NOTES FOR UNIT 5
-------
4. What is the point of application?
The inspector should determine that chemicals are being added at the
best point to achieve the desired results. The inspector should
alert the operator to improper application such as addition of
powdered activated carbon and chlorine at the same point.
5. Is proper mixing achieved based on visual observation?
The inspeetor should be looking for evidence of short circuiting.
6. What other pretreatment is provided?
Other processes should be noted and evaluated as to their sanitary
risks.
Chemical Feed
This section deals with chemical addition for such processes as coagu-
lation, lime softening, activated carbon addition, and corrosion control.
A good policy is for the inspector to draw a simple schematic of the plant
systems and where chemicals are added. The following questions apply to
chemical feed.
1. What chemical is used?
The inspector should determine what chemicals are utilized, and if
they are approved. The question should be asked as to how the dosage
is determined and frequency of this determination.
2. Where is it applied?
The inspector should note the application point and evaluate it in
light of the purpose of the chemical addition.
3. What is the condition of the feed equipment?
The equipment should be functional and properly maintained. For
example, with dry chemical feeders watch for problems with "bridging"
of the chemical in the hopper. Liquid solution feeder lines should
be observed to see that they are not clogged. The operator should be
asked if a preventive maintenance program exists and is utilized.
The care taken for the equipment of the facility could reflect the
operator's attitude towards the system as a whole. Cross connections
and the possibility of bacterial contamination of stock solutions
should be noted.
4. Are instrumentation and controls for the process adequate, opera-
tional, and being utilized?
Controlling processes is difficult when instrumentation is not
functional and/or properly calibrated. The instrumentation is
useless if the operator does not know the significance of the
measurement. The inspector should observe the controls and question
the operator about calibration checks and what is done based on the
measurement.
5-6-
-------
COURSE NOTES FOR UNIT 5
-------
5. Is chemical storage adequate and safe?
At least a 30-day supply of chemicals on hand is recommended. Level
indicators and overflow protection should be provided for liquid
chemical storage. This is particularly important for tanks located
near a well to prevent contamination of the aquifer. Chemicals
stored together should be compatible. For example/ hypochlorite and
activated carbon should not be stored near each other. Strong acids
should not contact chlorites. Chemicals should be stored in a manner
that would preclude a spill from entering the water being treated or
the source.
6. Are adequate safety devices available and precautions observed?
Safety goggles,' gloves, hearing protection, and respirators should be
provided for protection against injury by the particular chemicals.
The inspector should observe safety procedures during the
inspection. As stated previously, the inspector should be concerned
with safety, the operator's and his own.
1. Is nixing adequate based on visual observation?
Problems with short circuiting should be noted. Adequate solution
water and agitation should be provided in the case of dry chemical
addition.
2. Is equipment operated properly and in good repair?
Mixing can be accomplished by several means (mechanical mixers,
diff users, pump blenders, and baffles). The inspector should
determine that the particular means utilized is functioning properly.
Ploccula t ion/Sed imen tat ion
1. Is the process adequate based on visual observation?
The inspector should observe if there is good floe formation prior to
sedimentation. The best floe size ranges from 0.1 mm to about 3 nan.
There should be little carryover of the floe from the sedimentation
basin.
2. Is equipment operated properly and in good repair?
In the case of mechanical flocculators, the paddles should all be
present and turning. The flocculators should not break up the floe.
3. Are jar tests being performed to determine optimum dosage of
chemicals?
Proper coagulation and flocculation cannot be routinely achieved
without jar testing.
5-8
-------
COURSE NOTES FOR UNIT 5
-------
Filtration
Several types of filters are available for- use in water systems such as
diatomaceous earth, pressure sand filters, and rapid sand filters. As
stated previously, this manual provides only the "need to know" of sani-
tary risks involved with the components. The inspector should consult the
suggested references—for specific operational considerations.
1. Is process adequate based on observation?
The primary purpose of filtration is to remove turbidity. The
inspector should be concerned that the filtration process actually
reduces the turbidity. If there are multiple filters, the effluent
from each filter should be observed.
2. Are instrumentation and controls for the process adequate, opera-
tional, and being utilized?
Turbidity should be measured in the influent and effluent from the
filters. Head loss through the filter is also important to filter
operation, as is the use of flow rate controllers. The instruments
for these measurements and controls should be present and
functional. The operator should know the importance of the
readings. The answers provided should indicate the operator's
competence to the inspector.
3. Is equipment operated properly and in good repair?
For rapid sand filters, the inspector should look for problems such
as: mudballs, cracks in the media, backwashing difficulties
resulting in short filter runs and/or failure to clean media, and
loss of media. If a problem is indicated, the inspector may wish to
have the operator backwash the filter.
Poat-Chlor ination
The primary purpose of post-chlorination is disinfection. Disinfection is
the process of destroying a large portion of the microorganisms in water
with the probability that all pathogenic bacteria are killed in the
process* In water treatment, disinfection is almost always accomplished
by adding chlorine or chlorine compounds. Other processes that may be
encountered are; ultraviolet disinfection and the use of iodine or
ozone* The measure used to determine effectiveness of disinfection is the
coliform group. The standard test for the coliform group is either the
multiple-tub* fermentation technique or the membrane filter technique. An
in-depth discussion of these techniques may be found in "Standard Methods
foe the Examination of Water and Wastewater." The coliform group is used
as an indicator of pathogenic organisms. The use of this indicator group
haa several advantages over testing for specific pathogenic organisms.
Principally these advantages are:
1. Base of isolation: Using relatively unsophisticated analytical
procedures and equipment, the presence of coliforms can be
detected. The procedures can give results in 24 hours, making it
a comparatively rapid bacteriological test.
5-10
-------
COURSE NOTES FOR UNIT 5
-------
2. Coliforms are present in large numbers in feces of all animals:
Any fecal pollution results in the presence of coliform organisms
in sufficient quantities to determine the degree of pollution
with fair accuracy.
3. Coliforms are resistant to the forces of natural purification to
a greater degree than commonly encountered pathogens. Conse-
quently, the coliforras will normally still be present after the
disease-producing pathogens may have died off and will continue
to indicate the possible danger to the water.
Chlorination Terminology
Regardless of the form of chlorination, chlorine gas, or chlorine com-
pounds, the reaction in water is basically the same. The standard term
for the chlorine concentration is either milligrams per liter (mg/1) or
parts per million (ppm).
o Chlorine Dose; The total amount of chlorine fed into a volume of
water by the chlorinator.
o Chlorine Demand: Chlorine is a very active chemical oxidizing
agent. When injected into water, it combines readily with
certain inorganic substances that are oxidizable (hydrogen
sulfide, nitrite, ferrous iron, etc.) and with organic impuri-
ties including micro-organisms and decay products. These
reactions consume or use up some of the chlorine before it can
fully destroy micro—organisms. This amount used up is the
chlorine demand.
Chlorine Demand * Chlorine Dose - Chlorine Residual
o Chlorine Residual; The amount of chlorine (by test) present in
the water after the chlorine demand is satisfied and after a
specified time period. The presence of a "free" residual, in
contrast to a "combined" residual, of at least 0.2-0.4 ppm (in
relatively unpolluted, low turbidity water), after the chlorine
demand is satisfied, usually provides a high degree of assurance
that the disinfection of the water is complete.
A residual also provides some protection against any chance
contamination that may inadvertently enter the system. The
chlorine residual test sample is usually collected before the
first point in the distribution system where water is consumed.
Bowever, it is also advisable to also test at the farthest point
in the system to ensure that a residual exists throughout the
whole system. The residual test is the basis for increasing or
decreasing the chlorinator feed rate to achieve the desired
value. Too much chlorine residual will be offensive to some
consumers.
Chlorine Residual » Chlorine Dose - Chlorine Demand
5-12
-------
COURSE NOTES FOR UNIT 5
-------
o Chlorine Contact Time; The contact time is the time interval
(usually minutes) that elapses between the time when chlorine is
added to the water and the time when that same slug of water
passes by the sampling point. A certain minimum period of time
is required for the disinfecting action to become completed. The
contact time is usually a fixed condition dependent upon the rate
of flow..of .the water and the time it takes the water to pass
through the piping and storage facilities. Generally speaking,
it is preferable that the contact period be not less than 30
minutes under the peak demand flow conditions. However, even
more time may be necessary under unfavorable conditions.
Gas Chlorination
Chlorine gas is available in compressed gas form stored in steel
pressurized cylinders. A gas chlorinator meters the gas flow and mixes it
with water which is then injected as a water solution of pure chlorine.
Chlorine gas is a highly toxic lung irritant and special facilities are
required foe storing and housing gas chlorinators. The advantage of this
method is the convenience afforded by a relatively large quantity of
chlorine available for continuous operation for several days or weeks
without the need for mixing chemicals. Gas chlorinators have an advantage
where variable water flow rates are encountered as they may be syncronized
to feed chlorine at a variable rate.
Hypochlor ination
Most small system operators will find the use of liquid or dry chlorine
compounds mixed with water and fed into the system with inexpensive
hypochlorinators a satisfactory chlorination method. These small chemical
feed pumps are designed to pump (inject under pressure) an aqueous solu-
tion of chlorine into the water system. They are designed to operate
against pressures as high as 100 psi but may also be used to inject
chlorine solutions at atmospheric or negative head (suction side of water
pump) conditions.
The pumping rate is usually manually adjusted by varying the stroke of the
piston or diaphragm. Once the stroke is set, the hypochlorinator feeds
accurately at that rate. However, chlorine measurements should be made
occasionally at the beginning and end of the well pump cycle because if
the drawdown is high, the pumping rate varies considerably and the
concentration will vary since the applied dose is constant. A metering
device may be used to vary the hypochlorinator feed rate syncronized with
the water rate. Where a well pump is used, the hypochlorinator is
connected electrically with the on-off controls oŁ the pump.
The following questions deal with the sanitary risks of Chlorination.
1. Is adequate chlorine residual being maintained?
The answer to this lies in whether there have been any positive
coliform counts. The next step in determination of adequacy would be
to ensure that a detectable residual is present at the remotest
5-14
-------
COURSE NOTES FOB UNIT 5
-------
connection in the system. The inspector should review where the
utility's sample points within the distribution system are located
and/or how they were selected. If the inspector is to sample, a
deadend portion of the system that is remote from the plant may be
selected. A free residual of 0.2-0.5 mg/1 or a combined residual of
1.0-2.0 mg/1 should be maintained at the most distant points in the
system and a.t the- ends of deadend sections. The chlorinator should
have sufficient capacity to provide adequate treatment under peak
flow conditions.
2. Is there sufficient contact time between the chlorination point and
the first point of use?
Contact time should be a minimum of 30 minutes for free residual and
2 hours for a combined residual. This may be determined by figuring
detention time in the clear well, storage tank, and/or pipeline
between point of chlorination and use.
3. Is the equipment properly operated and maintained?
The inspector should determine that all equipment is operational and
preventive maintenance is routinely performed. Some indicators of
problems for gaseous chlorination would be valves, piping and
fittings that are damaged, badly corroded or loose, no gas flow to
the chlorinator, or frost on valves and piping. For powdered
disinfectants, some indicators are clogged feed lines and valves. A
more detailed discussion of these problems and their solutions is
provided in "Water Treatment Plant Operation," Chapter 7.
4. Is operational standby equipment provided? If not, are critical
spare parts on hand?
Disinfection must be continuous! Standby equipment of sufficient
capacity to replace the largest unit is recommended. Where it is
not, flow to the water system should be halted and critical spare
parts should be on hand for immediate replacement.
5. Is a manifold provided to allow feeding gas from more than one
cylinder?
As stated above, chlorination must be continuous. A manifold should
be provided to allow empty cylinders to be changed without stopping
chlorination. If only one cylinder can be utilized, the inspector
should determine what procedure is followed when it is changed. The
operator could be allowing water to continue to flow into the system
while he changes the cylinder, a process that could take 30 minutes.
Such a situation could result in contamination of the entire system.
6. Are scales provided for weighing cylinders?
Scales should be provided and utilized to measure the amount of
chlorine used each day and to determine when they are near empty so
they can be changed. These scales should be located so that the
cylinders will be cooler than the chlorinators to prevent condensing
of the chlorine in the lines.
5-16
-------
COURSE NOTES FOR UNIT 5
-------
7. Is the chlorine storage and use area isolated from other work areas?
Operators should be well versed on the hazards of chlorine gas,
proper handling of the gas and protective equipment, and the
limitations of the protective equipment. The inspector should be
knowledgeable in_these areas as well. A brief overview of chlorine
is that it Is a~heavier-than-air gas, which is corrosive in moist
atmospheres and is extremely toxic. Its toxicity ranges from throat
irritation at 15 ppra to rapid death at 1,000 ppra. Consequently, the
storage and use areas for chlorine should be above ground, well
ventilated, and separated by a gas-tight partition from other work
areas. Both chlorine gas and particularly sodium chlorite should not
be stored with organic compounds.
8. Is room vented to the outdoors by exhaust grilles located not more
than 6 inches above the floor level?
The room should be vented at a rate of one air change per minute with
exhaust grilles not higher than 6 inches above the floor. An inlet
grille for the room should be located near the ceiling. The vapor-
tight- fan switch should be located outside the room and equipped with
an indicator light. The inspector should ensure that the exhaust
from the chlorine room will, not enter into other interior areas.
Problems have resulted from locating the exhaust grilles to the
chlorine room in the vicinity of the makeup air inlet for other rooms,
9. Are all doors hinged outward, equipped with panic bars, and at least
one provided with a viewport?
The need for doors to be hinged outward is based on the fact that
someone in the room could be overcome and passed out against the
door, making rescue difficult if the door has to swing into the
room. The door should also have warning signs affixed, alerting
personnel to the dangers.
10. Is a self-contained breathing apparatus available for use during
repair of leaks?
The use of chlorine requires protective clothing. Chemical goggles
should be worn by personnel entering the area for routine inspec-
tion. When cylinders are changed or adjustments made to the system,
impervious gloves, chemical goggles, and a full face shield should be
worn (unless a full facepiece respirator or hood is used). Chlorine
canister-type gas masks are only acceptable if the known chlorine
vapor concentration is less than 1% and oxygen level greater than
16%. Additionally, canister-type gas masks must be checked routinely
and the canister changed when it has reached its expiration date or
has been damaged. When a worker enters a heavily contaminated area
for repair, a self-contained breathing apparatus is required. Use of
protective equipment and emergency drills should be practiced.
Emergency procedures should be coordinated with fire and police
personnel. The inspector should ask if the utility has an emergency
plan and if it has ever been practiced.
5-18
-------
COURSE NOTES FOR UNIT 5
-------
11. Are there means of leak detection?
The inspector should never enter a room containing chlorine gas
without first opening the door slightly to check for the smell of
chlorine. A squeeze bottle of dilute ammonium hydroxide can be used
for leak detection by squirting a small amount into the room prior to
entry. If. a leak is present a "snow" will form. There are also
continuous and portable chlorine detection devices that may be used.
12. Are all gas cylinders restrained by chaining to the wall or other
means?
Cylinders should be restrained to an immovable object. They should
be transported and stored in an upright position and kept away from
direct heat and direct sun. Empty containers should be segregated
from full containers.
13. Have there been any interruptions in chlorination during the past
year due to chlorinator failure or feed pump failure?
Any interruptions in chlorination and their cause should be
identified. The operator should be questioned as to what measures
have been taken to preclude recurrence of the interruption.
5-20
-------
COURSE NOTES FOR UNIT 6
-------
UNIT 6
Unit 61 GRAVITY STORAGE/HYDROPNEUMATIC TANKS
UNIT 6a: Gravity Storage
Unit Summary
Characteristics of a Gravity Storage System
Sanitary Risks
Unit References
Small Water Systems Serving the Public
(Chapter 6)
Manual of individual Water Supply Systems
(Part V)
Water Supply System Operation
(Chapter 5)
Basic Material
Hell supplies are often pumped directly to a gravity distribution reser-
voir (tank) from which water flows on demand to the points of use. The
wells may also be pumped directly into the distribution system with the
tank floating (riding) on the system. Either arrangement is acceptable.
The pumps may be controlled by water level float controls or pressure
switches. The storage tank is sufficiently elevated to ensure adequate
operating pressures.
A gravity storage system offers several advantages over other (e.g.,
hydropneumatic) systems and should be considered where topographic
conditions are favorable. The larger the water system, the greater the
advantages. However, even smaller systems will have these advantages:
o L«ss variation in pressure
o Storage for firefighting use
o One to two days' storage to meet water requirements
o Greater flexibility to meet peak demands
o Use of lower capacity wells (pumping not necessary
to meet peak system demand)
o Sizing of pumps to take better advantage of electric
load factors
o Reduced on and off cycling of pumps
o Tie-in of several wells, each pumping at its optimal rate
Since the gravity reservoir provides the storage necessary to meet the
peak system demands, the wells need not be developed to meet the peak
system capacities, as is generally necessary with pressure tank systems.
6-2
-------
COURSE NOTES FOR UNIT 6
-------
The wells should be capable of meeting the maximum day demand within the
period of time when water use is significant. For example, day schools
usually exert a significant water demand only over a 10- to 12-hour day.
The wells must, therefore, be pumped at a rate sufficient to meet the
maximum day demand in a 10- to 12-hour period. Under these conditions,
the reservoir (tank) should have an effective capacity equivalent to the
average daily demand.
Gravity distribution reservoirs may be elevated tanks mounted on
structural supports above ground, may be located partly below ground, or
may be tanks placed on pads or cradles on the ground surface. Elevated
tanks are necessary when high ground is not available within the service
area. The operating water levels of the tank should be sufficiently above
the distribution system to produce minimum operating pressures of 35 psi
(about 81 feet of head) but preferably 50-75 psi (116 to 173 feet).
Pressures should not exceed 100 psi (231 feet).
Shallow reservoirs with large diameters are preferred over deep ones with
smaller diameters, other things being equal. Tanks with larger diameters
have more water per foot, of drawdown and are thus less prone to pressure
fluctuations. They are also less costly to build.
Prefabricated standpipes and elevated tanks are readily available with a
wide range of capacities. Prestressed concrete tanks are quite popular,
since they require less maintenance.
Sanitary Risks
1. Does surface runoff and underground drainage drain away from the
storage structure?
2. Is site protected against flooding?
Storage reservoirs should be located above probable ground water
levels. Surface runoff and underground drainage should be away from
the structure. Provisions should be included to guard against the
sanitary-hazards related to location; groundwater levels, movements,
and quality; character of soil; possibility of wastewater pollution;
and overtopping by floods. Sites in ravines or low areas subject to
periodic flooding should be avoided. Any sewer located within 50
feet of a storage reservoir with a floor below ground level should be
constructed of extra-heavy or service-weight cast iron pipe with
tested, watertight mechanical joints. No sewer should be located
less than 10 feet from the reservoir.
All storage reservoirs should be protected against flood waters or
high water levels in any stream, lake, or other body of water. These
reservoirs should be placed above the high water level, and the
structure and its related parts should be watertight. The ground
surface above the reservoir should be graded to drain surface water
away froa the reservoir and to prevent pooling of surface water
within the vicinity. Walls or fencing should surround open
reservoirsr and public access should be prohibited.
6-4
-------
COURSE NOTES FOR UNIT 6
-------
3. Is storage tank structurally sound?
The inspector should base the answer to this question on visual
observation. Look for washouts and signs of foundation failure.
4. Are overflow lines, air vents, drainage lines, or cleanout pipes
turned downward or covered, screened, and terminated a minimum of
3 diameters" above the ground or storage tank surface?
Any overflow, blowoff, or cleanout pipe from a storage reservoir
should discharge freely into an open basin from a point not less than
three diameters of the discharge pipe above the top or spill line of
the open basin. All overflow, blowoff, or cleanout pipes should be
turned downward to prevent entrance of rain and should have removable
124-mesh screens to prevent the entrance of birds, insects, rodents,
and contaminating materials. If the discharge pipes are likely to be
submerged by surface or flood water, a watertight blind flange should
be provided to attach to the pipe opening to prevent contaminated
water back flow into the reservoir. If the reservoir must be emptied
when the normal outlet is submerged by surface or flood waters, pumps
with outlets above the flood water should be used for emptying.
5. Is site adequately protected against vandalism?
Manholes and manhole frames used on covered storage reservoirs and
elevated tanks should be fitted with raised, watertight walls. Each
manhole frame should be closed with a solid watertight cover and a
sturdy locking device. The frame should be locked when not in use.
The storage site should be fenced to prevent unauthorized entry.
Ladders to tops of storage tanks should terminate 10 feet above the
ground to deter unauthorized climbing.
6. Are surface coatings in contact with water approved?
Coatings that are in contact with water should be approved.
Unauthorized coatings can create problems due to organic and
inorganic contamination of the stored waters.
7, Is tank protected against icing and corrosion?
Cathodic protection may be provided for metal storage tanks, icing
can be a particularly traumatic problem in northern areas. Tanks
have "blown their tops" due to the pressures that can result; in less
severe cases, the cathodic protection and tank interiors may be
damaged. Tanks should not be allowed to remain idle if freezing is a
problem. Heaters may need to be used in tanks reserved for emergency
purposes.
8. Can tank be isolated from the system?
Tanks should be able to be taken out of the system for repair without
shutting down entire system.
6-6
-------
COURSE NOTES FOR UNIT 6
-------
9. Is all treated water storage covered?
Reservoirs should be covered to prevent airborne contamination (birds
and algae growths that impart tastes and odors). Covers should be
watertight, made of permanent material, and constructed to drain
freely and to prevent contamination from entering the stored water.
The surface of a storage reservoir cover should not be used for any
purpose that may result in contamination of the stored water.
10. What is cleaning frequency for tanks?
Over a period of time, reservoirs may accumulate organic and inor-
ganic debris, which settles to the bottom as a sludge. This sludge
can contribute taste, odors, and turbidity to the systems when it
accumulates to a depth approaching the outlet pipe. Periodic drain-
ing of the tank and cleaning,is necessary. The tank should then be
disinfected before reuse.
11. Are storage tanks disinfected after repairs?
Reservoirs and elevated tanks on the distribution system should be
disinfected before being put into service or after extensive repairs
or cleaning have been completed.
6-8
-------
COURSE NOTES FOR UNIT 6
-------
UNIT 6b: Hydropneumatic Tanks
Unit Summary
Types and Characteristics
Sanitary Risks
Unit References
Small Water Systems Serving the Public
(Chapter 6)
Manual of Individual Water Supply Systems
(Part V)
Planning for an Individual Water System
(Chapter V)
Water Supply System Operation
(Chapter 3 and 5)
Basic Material
Hydropneumatic systems are very common for use in storing and distributing
small water_ supplies. They combine the energy from a pump with the
principle of air pressure to force water into the distribution system.
Understanding how the hydropneumatic system is susceptible to sanitary
risks requires understanding basic system operation and the role of system
components.
The system operates in the following manner:
o The pump starts up at a certain pressure (cut-in pressure), and the
energy from the pump moves through water to the pocket of air, air
volume, at the top of the pressure tank..
o When the pressure builds to a certain point (cut-out pressure) / the
pump stops and the air forces the water into the distribution
system.
o When the pressure becomes too low, the pump starts up again, and
the cycle is repeated. The cycle rate is» the number of times the
pump starts and stops in 1 hour.
A typical hydropneumatic system is made up of the following parts:
6-10
-------
COURSE NOTES FOR UNIT 6
-------
Item Purpose
o Steel tank Store water
o Air volume control Control air volume
o Relief valve Prevent excessively high pressure
o Inlet-piping Allow flow of water into system
o Pressure gauges Monitor pressure
o Motor controls Control cut-in and cut-out points
o High/low water level controls Regulate water level
o Low pressure or flow controls Maintain balance between water and
air pressure
o Discharge piping/air Discharge water from tank; force
compressor additional air in to increase
pressure (prepressurizing)
Most systems differ only in the kind of pressure storage tank used. The
pressure tank is a significant part of the•system in that the methods of
separating water and air and the tank size and placement vary. All these
factors may contribute to the degree of vulnerability to sanitary risks.
The three kinds of tanks are:
Conventional
o Air cushion in .direct contact with water; air volume controls
necessary
o Capacity ranges from a few to several thousand gallons
o Vertical or horizontal placement
o Outlet located near bottom of tank; combined inlet-outlet or
separated on opposite sides of tank
o Air volume control located in upper portion of tank; provisions
available for prepressurizing
Floating Wafer
o Floating wafer (rigid floats or flexible rubber or plastic)
separates water and air, but separation not complete; some loss of
air expected, requiring occasional recharging
o Vertical placement limits tank capacity
o Inlet and outlet combined at bottom of tank
o Internal air check valve to prevent premature loss of air due to
electric outage or excess water demand
Flexible Separators
o Separator fastened around inside of tank for complete separation of
air and water, either flexible diaphragm or bag type
o Vertical placement limits tank capacity
o Supercharged at factory to pressures just below pump starting
pressure
6-12
-------
COURSE NOTES FOR JNT
-------
Sanitary Risks
1. Does low pressure level provide adequate pressure?
Maintenance of adequate pressure is especially important. Too little
pressure can cause a reversal in the flow of the water, allowing water
from a polluted source to enter a potable, stored water source. TOO
high pressure cair strain system components, cause high leakage rates,
and can force air out with water. Low pressure can indicate improper
connections, or cross-connections, made from storage to serviced
facilities. Adequate pressure is needed to keep the water flowing from
storage to serviced areas. Backpressure backflow occurs when potable""
water pressure is less than nonpotable pressure; backsiphonage back flow
is a reversal stemming from a vacuum at the potable supply. Back flow
and backsiphonage are especially hazardous sanitary risks when they
involve poisonous or harmful chemicals. Inspectors must be aware of
proximity of polluted sources and must protect stored water against
cross-connections.
To ensure against backflow and backsiphonage, minimum pressure must be
maintained at all times.
System Pressures
(Pounds Per Square Inch)
Optimum Working Pressure =» 40-60 psi
Minimum Working Pressure » 35 psi
Maximum Pressure at Service Connections * 100 psi
Minimum Pressure at Service Connections - 20 psi
Inspectors should check engineering records to assess potential hazards
in the water of facilities served by the system and consult operating
records to see whether pressure is adequate at service connections.
2. Are instruments and controls adequate, operational, and being utilized?
Proper operation and maintenance of the storage system is also essen-
tial. Failure to adjust gauges and controls properly can lead to in-
adequate pressure and/or inadequate supplies of water. Also, pollution
of the storage tank can occur from airborne or waterborne foreign
matter. Careful installation and maintenance of pollution prevention
devices can prevent, their entry into the hydropneumatic system.
To ensure proper operation and maintenance1 of the system, the
following components must be routinely checked and adjusted for
changes in the peak demand:
o Air volume control
o Relief valve
o Motor controls
o High/low water level controls
o Low pressure flow controls
o Air compressor and controls
6-14
-------
COURSE NOTES FOR UNIT 6
-------
Frequently, controls are not adjusting after delivery of the system
from the factory. Operating records will reveal original calibration
and whether peak demand has changed.
3. Are the interior and exterior surfaces in good condition?
The interior and-exterior should be in good physical condition. The
inspector may not be able to inspect the interior surfaces but should
emphasize the importance of regular inspections. The inspector may
determine if they are being performed by reviewing maintenance records,
4. Are tank supports structurally sound?
The tank should be properly supported.
5. Is storage capacity adequate?
There are several formulas for determining required storage capacity.
One method is presented.
In selecting and evaluating the tank, storage capacity must be matched
to the peak demand (period of highest water use) of the system.
Otherwise, the tank will supply neither sufficient daily water needs
nor emergency needs, such as for firefighting.
To ensure against inadequate storage capacity (and straining facili-
ties at peak demand), purveyors must know pumping capacity and peak
demand rates, which can be used, in the formula below to compute
appropriate tank size. Engineering records list pump capacity, cut-
in, and cut-out pressures. Operating records show current peak demand
and whether peak demand has changed since the tank was installed,
which could require a change in tank size.
Formula for Estimating
Appropriate Tank Size
Q-__25L
Q • Tank volume in gallons
QR » Peak demand rate, gpm x desired minutes of storage
P! • Cut-in pressure + atmospheric pressure (14.7 psi)
P2 » Cut-out pressure + atmospheric pressure (14.7 psi)
6. What is the cycle rate?
The pressure pump should not cycle frequently (10-15 cycles/hour
acceptable). Frequent or constant operation of the pressure pump
indicates a "waterlogged" tank or improper settings on the pressure
controls.
6-16
-------
COURSE NOTES FOR UNIT 6
-------
Top
Manhole
n>
Ladder•
Vent
^ Overflow
Splash Pad
J4
Gravity Storage Tank
-------
COURSE NOTES FOR UNIT 6
-------
(D
I
VANDALISM
-------
COURSE NOTES FOR UNIT 6
-------
a»
Pump
AIR
WATER
Maximum Pressure
100 psi
CUT-OUT PRESSURE
-------
COURSE NOTES FOR UNIT 6
-------
Types of Pressure Tanks
CONVENTIONAL WAFER DIAPHRAGM WATER IN BAG AIR IN BAG
Air
Volume
AIR
WATER
AIR
WAFER
WATER
AIR
DIAPHRAGM
WATER
AIR
BAG
— WATER
4
-------
COURSE NOTES FOR UNIT 7
-------
urti.j.
Unit 7: DISTRIBUTION SYSTEMS/CROSS-CONNECTIONS
UNIT 7a: Distribution Systems
Unit Summary
Components of a Distribution System
Sanitary Risks
Unit References
Small Water Systems Serving the Public
(Chapter 11)
Manual of Individual Water Supply Systems
(Part V)
Manual for Evaluating Public Drinking Water
Supplies (Part III)
Hater Supply System Operation
(Chapters 6, 7, and 8)
Basic Material
Many failures to meet the requirements of the drinking water standards are
directly related to the use of poor operating and maintenance procedures
for distribution systems or to the presence of sanitary defects in the
system. Some causes that contribute to poor water quality are:
o Insufficient treatment at the point of production
o Cross-connections
o Improperly protected distribution system storage
o Inadequate main disinfection
o Unsatisfactory main construction, including improper joint-packing
o Close proximity of sewer and water mains
o Improperly constructed, maintained, or located blowoff, vacuum, and
air relief valves
o Negative pressures in the distribution system
Component3 of the Distribution System
Th« following briefly describe some of the important components of a
distribution system.
7-2
-------
COURSE NOTES FOR UNIT 7
-------
Pipes
o Convey supply to points of use
o Pipe size relative to flow gpra, distance
o Types
o Galvanized. Not recommended for underground use; subject to
corrosion from soil, acid water
o Copper--._Heavy types used underground; less sensitive to
corrosion
o Plastic. Corrosion resistant; subject to puncture
o Cast Iron/Ductile Iron. Corrosion resistant; good hydraulic
characteristics; unlined pipe can be subject to iron tubercles
o Asbestos Cement. Lightweight, corrosion resistant; easily cut
but easily broken
o Lead, used in older systems, particularly as service lines. No
longer approved under any circumstances due to possibility of
contaminating tapwater.
Valves
o Control water flow
o Control backflow
o Adjust water levels and pressures
o Isolate sections of system for repair
o Types
o Shut-Off valves stop flow of water.
o -Check Valves permit water to flow in one direction only.
o Plow Control Valves provide uniform flow at varying pressures.,
o Relief Valves permit water to escape from the system to relieve
excess pressure.
o Float Valves respond to high water levels to close an inlet pipe.
o Blowoff Valves provide a means to flush sediment from low
points/deadends in the distribution system.
o Altitude Valves are used to shut off flow of water into storage
tank at a preset level to avoid overflow and allows water to
flow into tank after level drops.
o Air Relief Valves are used at high points to release entrapped
air.
o Hydrants provide water for firefighting and are a means to flush
the system.
Meters
o Monitor flow through various sections to provide regulation,
reimbursement, and maintenance
Meter vaults
o Protect meters and controls
Thrust Blocks and Anchors
o Protect against pipe movement
7-4
-------
COURSE NOTES FOR UNIT 7
-------
Sanitary Risks
The questions that a surveyor should' be asking with regard to the
distribution system and their rationale follow.
1. Is proper pressure (40-70 psi) maintained throughout the system?
The system should be designed to supply adequate quantities of water
under ample pressure and should be operated to prevent, as far as
possible,.conditions leading to the occurrence of negative pressure.
Steps to prevent negative pressure should include minimizing planned
shutdowns, providing adequate supply capacity, correcting undersized
conditions, and properly selecting and locating booster pumps to
prevent the occurrence of a negative head in piping subject to
suction. Continuity of service and maintenance of adequate pressure
throughout a public water supply system are essential to prevent
backsiphonage. The inspector should determine if complaints about
inadequate pressure have been registered. He or she should determine
if there is a program to periodically monitor pressures throughout the
system.
2. What types of construction materials are used?
The components of the distribution system should meet the current AWWA
standards. The corrosive effects of finished water on nonferrous
metal pipe used for water-service lines should be considered, together
with possible toxicological effects on consumers, resulting from
solution of the metals. Only nontoxic plastic pipe should be used,
when plastic pipe is acceptable. Materials used for caulking should
not be able to support pathogenic bacteria and should be free of oil,
tar, or greasy substances. Joint packing materials should meet the
latest AIWA specifications.
3. Are plans of the water system available and current?
The minimum record of a distribution system contains maps showing
locations of all mains, main size, and the location in detail of every
line valve. The pipe layout should be designed for future additions
and connections to provide circulation where deadends are necessary in
the growth state of the pipe system. The system should be provided
with sufficient bypass and blowoff valves to make necessary repairs
without undue interruption of service over any appreciable area.
Blowoff connections to sewers or sewer manholes should be prohibited.
4. Does the system have an adequate maintenance program?
This is actually an overall evaluation of the answers to a series of
questions, such as:
a. What is the frequency of main breaks?
The majority of breaks are not due to age but to leaks. The leaks
undermine the pipe, consequently causing it to fail under the
weight of the overburden. To prevent main breaks, a routine
program for leak detection should be conducted.
7-6
-------
b. Does the utility have a pressure testing program?
Such a program may be conducted in conjunction with the fire
department to determine adequacy of fire flow. A record of
pressures throughout the system may help to ide-tifv problems.
If they are conducted both during the day and at night, th y will
indicate..-the hydraulic efficiency under common requirements.
c. Does the utility have a flushing program?
.The whole system should be flushed once or twice a year due to
sediment deposition in the lines. The flushing should be well
planned and carried out, beginning at points near the water
plant/storage and moving to the outer ends.
d. Does the utility have a valve maintenance program?
All valves in a system should be inspected on a routine basis.
The frequency of inspection depends on type of valve, but an
annual inspection is desirable for all valves. This should
include completely closing, reopening to about one-quarter, and
reclosing until valve seats properly. A record of valve
maintenance and operation should be kept.
e. Does the utility have a corrosion control program?
The utility should have a program to evaluate corrosion and the
effectiveness of corrosion control particularly to control
contaminants such as lead and cadmium.
f. Are proper disinfection procedures used after repairs?
The procedure outlined in the AWWA Standard for Disinfecting
Water Mains should be followed. The inspector should question
the operator as to what procedures are used. The final
determining factor should be that new mains and repaired main
sections should demonstrate negative bacteriological results
prior to being placed in service.
5. Is the system interconnected with any other water systems?
This of of concern for two reasons:
a. The water systems to which it is connected may be of a lower
quality and potentially pose a risk.
b. The other water system may provide an alternate source in the
case of drought, contamination of the primary source or a similar
emergency.
The inspector should evaluate the answers to such questions and the
availability of records to determine the adequacy of the maintenance
program.
7-8
-------
COURSE NOTES FOR UNIT 7
-------
COURSE NOTES FOR UNIT 7
-------
UNIT 7b: Cross-Connections
Unit Summary
Type and Characteristics of
Cross-Connections
Sanitary Risks
Unit References"
Small Water Systems Serving the Public
(Chapter 15}
Cross-connection Control Manual
Water Supply System Operation
(Chapters 6 and 8)
Basic Material
To prevent contamination of the community's water supply, the purveyor
must make sure that service connections are properly made and are
continually monitored for cross-connection hazards. A cross-connection is
a physical connection or arrangement between otherwise separate piping
systems containing potable and other water, whereby water may flow between
the two systems. Hazards occur when water flows toward the potable supply
instead of from it to the service outlets. Unless controlled, cross-
connections can result in contaminated water replacing potable water at
various sites within a water system. If the contaminated water is
unobstructed and its force is great enough, it can enter the potable
supply at the water facility, endangering the health of the entire
community.
A cross-connection link can be made either as a pipe-to-pipe connection,
in which potable and contaminated water pipes are linked without the
proper control valves, or as a pipe-to-water connection, in which the
outlet from a potable water supply is submerged in contaminated water.
Cross-connections are usually made unintentionally or are made because
their hazards are not recognized. The two major types of cross-connection
hazards—backpressure backflow and backsiphonage backflow—are
distinguished by their origins. Backpressure backflow refers to the flow
of water toward a potable supply when the contaminated water's pressure is
greater than the potable water's pressure. Contaminated water pushes
toward the potable supply. (Liquid flows from a place of high pressure to
one of lower pressure.) Backsiphonage backflow is a type of backflow
resulting from negative pressure (a vacuum) in the distributing pipes of a
potable water supply. Contaminated water is sucked up toward the potable
supply.
7-10
-------
COURSE NOTES FOR UNIT 7
-------
Plumbing defects can occur within any part of a water system, and cross-
connection hazards can occur where outside water pressure can exceed
potable water pressure. Therefore, cross-connections must be prevented or
controlled at all service sites as well as at the water facility.
Successful control of cross-connection hazards depends not only on
voluntary monitoring of connections by the water purveyor and water users,
but also on an enforceable community control program. If a community
subscribes to a modern plumbing code, such as the National Plumbing Code,
its provisions will govern backflow and cross-connections. Still, the
water facility must obtain authority to conduct a community inspection
program through an ordinance or other means. A cross-connection control
ordinance should have at least three basic parts:
o Authority for establishment of a program.
o The technical provisions relating to eliminating backflow and
cross-connections«
o Penalty provisions for violations.
Protection Against Sanitary Risks
»
At Service Sites; Cross-connections that occur at sites serviced by the
water facility can usually be controlled at the sites themselves. For
example, a submerged water outlet in an apartment building could result in
contamination of the water for the entire building (as well as threatening
the water facility's supply) if the water pressure of the contaminated
water exceeds that of the potable water. To prevent this cross-connection
hazard, each fixture in the building should have a vertical airgap between
its water outlet and its flow-level rim. This will eliminate the physical
cross-connection link and protect the building (and the municipal supply)
against backflow. An airgap separation may also be made at a point where
the water service enters the building. (This protects only the municipal
supply, however, and not the building system.) Backflow prevention
devices, such as double-check, double-valve assemblies, can be installed
when an airgap cannot be made. They can also provide backup when airgaps
are made. Surge tanks, booster systems, and color-coding and labeling of
pipes in dual water systems also protect buildings against cross-connection
backflow. Backsiphonage can be prevented by installation of vacuum-
breaking devices at water outlets where contaminated water is used and
where a vacuum could occur in the water supply pipe.
At the Water Facility; To lessen the chances of hazardous cross-
connections, water facilities should not be connected to unapproved
systems or to private wells. If connections must be made to wastewater
treatment plants, boiler plants, and other sites with inherently dangerous
contaminants, the connections must be carefully monitored at the facility
to prevent contamination from entering the water supply. An airgap in
the service line to a premise at which extreme hazards exist may be
warranted. Waterworks officials often prescribe the installation of a
backflow prevention device in the service line to a premise where
7-12
-------
COURSE NOTES FOR UNIT 7
-------
hazardous use of water is found. Lesser hazards can often be prevented
with back flow prevention devices in other locations. Backflow prevention
devices are critical (used exclusively or as backup) in all water
facilities because any water pressure greater than that of the facility
could cause a flow reversal. Maintenance of systematic water pressure
will prevent backsiphonage stemming from the water facility. The facility
must also install and maintain devices that block backsiphonage flow as a
backup in cases when pressure does drop. (This can occur if a main break
or a fire overburdens the pumping capacity.)
Types of Devices;
Vacuum Breaker; A device that is activated by atmospheric pressure to
block the water supply line when negative pressure develops in the line.
This action admits air to the line and prevents backsiphonage. A vacuum
breaker is not designed to provide protection against backflow resulting
from backpressure, and should not be installed where backpressure may
occur.
(See Figure 7-1)
Pressure-Type Vacuum Breaker; This device is installed in pressurized
systems and will operate only when a vacuum occurs. It is usually spring !
loaded, and should be specially designed to operate after extended periods,;
under pressure because corrosion and deposition of material in the line j
might render it inoperable.
Ą.(.• J
(See Figure 7-2)
7-14
-------
COURSE NOTES FOR UNIT 7
-------
Reduced Pressure Zone Backflow Preventer (RPZ); This device consists of
two hydraulically or mechanically loaded pressure-reducing check valves,
with a pressure-regulated relief valve located between the two check
valves. Flow from the left enters the central chamber against the
pressure exerted by the loaded check valve 1. The supply pressure is
reduced by a predetermined amount. The pressure in the central chamber is
kept lower than tR~e incoming supply pressure through the operation of
relief valve 3, which discharges to the atmosphere whenever the central
chamber pressure is within a few pounds of the inlet pressure. Check
valve 2 is lightly loaded to open with a pressure drop of 1 psi in the
direction of flow and is independent of the .pressure required to open the
relief valve. In the event that the pressure increases downstream from
the device, tending to reverse the direction of flow, check valve 2
closes, preventing backflow. Because all valves may leak as a result of
wear or obstruction, the protection provided by the check valves is not
considered sufficient. If some obstruction prevents check valve 2 from
closing tightly, the leakage back into the central chamber would increase
the pressure in this zone, the relief valve would open, and flow would.be
discharged to the atmosphere.
When the supply pressure drops to the minimum differential required to
operate the relief valve, the pressure in the central chamber should be
atmospheric. If the inlet pressure should drop below atmospheric
pressure, relief valve 3 should remain fully open to the atmosphere to
discharge any water that may flow back as a result of backpressure and
leakage of check valve 2.
Malfunctioning of one or both of the check valves or relief valve should
always be indicated by a discharge of water from the relief port. Under
no circumstances should plugging of the relief port be permitted because
the device depends on an open port for safe operation. The pressure loss
through the device may be expected to average between 10 and 20 psi within
the normal range of operation, depending upon the size and flow rate of
the device.
(See Figure 7-3)
Normal Direction of Flow
Direction of Flow
7-16
-------
COURSE NOTES FOR UNIT 7
-------
Double-Check, Double-Gate Valve Assembly; The double-check, double-gate
valve assembly is a very useful and, when properly maintained, reliable
means of backflow protection for intermediate degrees of hazard. AS in
the case of other backflow preventers, the double-check, double-gate valve
assembly should be inspected at regular intervals. Some health authori-
ties have established programs of annual inspection.
The double-check, double-gate system has the advantage of a low head
loss. With the gate valves wide open, the two checks, when in open
position, offer little resistance to flow.
Double-check, double-gate assemblies should be well designed and con-
structed. The valves should be all bronze or, for larger sizes,
galvanized gray iron. The trim should be of bronze, or other corrosion-
resistant material. Springs should be bronze, stainless steel, or spring
steel covered with a coat of vinyl plastic. Valve discs should be of
composition material with low water absorption properties. Test cocks
should be provided.
Q«t» A
T««r Cocks
Sanitary Risks
To evaluate the potential risks of cross-connections, the inspector should
determine the answers to the following:
1. Does the utility have a cross-connection prevention program?
The inspector should determine if the water facility has obtained
authority to conduct a community inspection program through an
ordinance or other means. A cross-connection control ordinance
should have at least three basic parts:
o Authority for establishment of a program
o The technical provisions relating to eliminating backflow and
cross-connections
o Penalty provisions for violations
7-18
-------
COURSE NOTES FOR UNIT 7
-------
2. Are backflow prevention devices installed at all appropriate
locations (wastewater treatment plants, hospitals, industrial
locations)?
The threat of cross-contamination hazards is especially great at
wastewater treatment plants, boiler plants, chemical manufacturing
plants, hospitals, and nuclear power plants. Their water may contain
inherently dangerous materials. These sites should be ensured
against physical links and should be equipped with devices to prevent
backflow and backsiphonage from contaminating water on the premises.
3. Are cross-connections present at the treatment plant?
The inspector should briefly discuss with the operator the importance
of ensuring that there are no cross-connections at the plant either
on a temporary or permanent basis. One way to help minimize the
potential of cross-connections is to have the piping in the plant
color coded. The primary sources of cross-connections in the
treatment plant are submerged inlets to solution tanks, connections
between potable water lines and process water lines, and at pumps.
When using phosphate solutions, tanks must be kept covered and
disinfected by carrying a 10 rag/1 free chlorine residual to prevent
the growth of bacteria.
7-20
-------
Vacuum
•s
M
n
DUc
n
+
Atmospheric/
Prvisur*
/•,
V. Almoiphcric
Pr«t»ur«
I
Disc In Normal Votuum Flow Jo$l a'ler
Flow Poiilion / Vacuum i* Applied
Atmospheric
Pr«*»ur«
L
Ą
Almoiphtric
Disc in Vacuum
Breaking Position
Operation of a vacuum breaker.
-------
COURSE NOTES FOR UNIT 7
-------
Valve 2
/ f 7 7 7^7 7 7 J 7 7 777
7/7//Y////S/7/7
Test Cock
ro
-\
Valve 1
Pressure-type vacuum breaker installation.
-------
COURSE NOTES FOR UNIT 7
-------
O
^1
I
Normal Direction of Flow
Reversed Direction of Flow
Reduced pressure zone back flow preventer —
principle of operation.
-------
COURSE NOTES FOR UNIT 7
-------
COURSE NOTES FOR UNIT 8
-------
UNIT 8
Unit 8s MONITORING/RECORDKEEPING/SAHPLING
Unit 8a: Monitoring
Unit Summary
Monitoring Responsibility
Monitoring Requirements
In-plant Monitoring
Unit References
National Interim Primary Drinking Water
RegulatIons
Water Treatment Plant Operation Vol. I
CChapter 10)
Basic Material
The National Interim Primary Drinking Water Regulations (.NIPDWR)
outlining responsibilities and requirements of the water purveyor
with respect to monitoring. The responsibilities for monitoring
are:
1. Arrange for all applicable sampling required In the
regulatIons.
2. Arrange for sample examinations at a State-approved
laboratory.
The requirements for sampling frequency are provided in the
tables Included In this unit.
8-2
-------
COURSE NOTES FOR UNIT 8
-------
TABLE 8-1
Frequency Requirements for Sampling and Analysis
MICROBIOLOGICAL
Contaminant
Surface Source
Ground Source
Coliform Bacteria
Monthly, based on
population served
Community systems of
less than 1,000 people,
a minimum of one per
month
Noncommunity systems,
a minimum of one per
calendar quarter
Same as for surface
sources except that
State agency may
reduce to one sample
per calendar quarter
INORGANIC CHEMICALS
(Applies only to community systems except for
Nitrate, which applies to both community and
noncommuni ty)
Contaminant
Surface Source
Ground Source
Arsenic
Barium
Cadmium
ChroBium
Lead
Mercury
Selenium
Silver
Fluoride
Nitrate
Analysis at 1-year
intervals
Analysis at 3-
year intervals
8-4
-------
COURSE Nt)TES FOE UNIT 8
-------
ORGANIC CHEMICALS
TABLE 8-1 (cont.)
Contaminant
Surface Source
Ground Source
Endrin
Lindane
Methoxychlor_
Toxaphene 2,4-D
2,4,5-TP Silvex
Total Trihaio-
methanes
Analysis at 3-year
intervals
Sampling and analysis
conducted quarterly
Analysis only if
required by the
State
(Individual States may require greater frequency of sampling and analysis.
RADIOACTIVITY (Applies only to community-type systems)
Contaminant
Surface Source
Ground Source
Natural
Radioactivity
Analysis completed
at 4-year intervals
Analysis completed
within 3 years
after effective date;
thereafter at 4-
year intervals
SODIUM (Applies only to community-type systems)
Surface Source
Ground Source
Sampling and analysis
conducted annually
Sampling and analysis
conducted every
3 years
8-6
-------
COURSE NOTES FOR UNIT 8
-------
TABLE 8-1 (cont.)
CORROSIVITYJZHARACTERISTICS CApplles only to community-type
systems)
Surface Source Ground Source
COne round of Two samples to be taken Only one sample
sampling and one midwinter and one and analysis
analysis) midsummer required
CNote: Individual states may require a greater frequency.of
sampling and analysis.
TURBIDITY
Surface Source Ground Source
Sampling of at least Not applicable
once per day
With respect to this In-house monitoring, the Inspector should be
concerned with the following points:
1. Is the operator competent In performing the tests?
The Inspector may wish to observe the operator's technique In
collecting samples and performing analyses. The operator ghoul;
follow the correct procedures such as calibrating and zeroing
specific Ion electrodes. The operator should be aware of ,
Interferences that may cause Incorrect readings.
2. Are testing facilities and equipment adequate?
The water utility should be encouraged to have equipment to
enable proper operational monitoring. The equipment should be
In working order- The Inspector may wish to look at the equip;
ment. The operation of the plant Is not aided by a pH elec-
trode that the operator has been using which has been dry for
the last six months. The facilities should be adequate for thj
equipment utilized. Many of the electronic Instruments are
Influenced by temperature and humidity.
3. Do reagents used have an unexplred shelf life?
The operator should be encouraged to mark the date of prepara-
tion on reagents and to discard when appropriate. The
8-8
-------
COURSE NOTES FOR UNIT 8
-------
manufacturer—prepared reagents should be discarded when the
expiration date Is reached.
4. Are records of test results being maintained?
The records of test results should be kept so that trendg uja
observed. The Inspector should determine what action is tafc
based on the tnst results. The operators should know the
Importance of the particular test and what the results mean.
For operational water quality monitoring the following parameter;
are generally tested:
Temperature Color
pH Iron
Alkalinity Manganese
Chlorine Residual Flourlde
Hardness Phosphate
Carbon Dioxide Total Collform
Turbidity
Using the parameters listed above and any other you feel necessa;
list those you feel are necessary to properly monitor the treatij
processes In the three problems below. Assume the role of the pj
operator as you perform this exercise.
SCHEMATIC OF CONVENTIONAL SURFACE WATER PLANT
Figure 8-1
SCHEMATIC OF IRON REMOVAL FACILITY
Figure 8-2
SCHEMATIC OF GROUNDWATEH SYSTEM WITH SIMPLE CHLORINATION
Figure 8-3
8-10
-------
NOTES FOR JNIT i
-------
Unit 8b: Recordkeeplng
Unit Summary
Bacteriological Analysis
Chemical Analysis
Corrective Action Records
Unit References
Manual of Instruction for Water Treatment
Plant Operations CChapter 8)
Water Treatment Plant Operation Vol. I
([Chapters 3, 4, 9, and 10}
Small Water System Operation & Maintenance
CChapters 1. 3, 4, and 5}
Basic Material
The following records must be kept by the water supplies as outlln«
by NIPDWRs
Bacteriological analyses - for at least five years.
Chemical analyses - for at least ten years. Actual
laboratory reports may be kept, or data may be transferred
to tabular summaries, provided that the following
Information Is Included:
Date; place, time of sampling, name of person collecting
Identification of routine distribution system sample,
check, samples, raw or process water samples, special
purpose samples, date of analyses
Lab and person responsible for performing analysis
Results of analysis
Records of action taken to correct violations - for at leas
three years after last action was taken with respect to a
particular violation.
. Coplea_of _wr 11 tenure port a . _aumiiar lea_or_eommr|} eat ions
relating to sanitary surveva conducted by Itself, private.
consultant, or local. State, or Federal agency - for at
least ten years after completion of sanitary survey
Involved.
Records concerning scheduling of Improvements - not leas
than flv« years following expiration of scheduling time.
8-12
-------
COURSE NOTES FOR UNIT 8
-------
Unit 8c: Sampling
Unit Summary
Representative Samples
Sample Collection Techniques and Location
Sample Handling and Preservation
Unit References
Manual of Instruction for Water Treatment
Plant Operations CChapter 21}
Manual of Water Utility Operations
CChapter 12)
Water Distribution System Operation &
Maintenance CChapters 5 and 6)
Water Treatment Plant Operation Vol. I
CChapters 4, 6, 7, and 11}
Small Water System Operation & Malntenanc
CChapter 7}
Basic Material
The inspector should ensure that the required monitoring is being
conducted and that analysis is performed by a certified laboratory.
Recordkeeping should also be evaluated to determine compliance with the
regulation.
The previously discussed, monitoring is required to comply with the
regulations. The analysis for those samples„ with the exception of
turbidity and chlorine residual, must be conducted by an approved
laboratory. The operator must establish an in-house monitoring program to
properly evaluate the operation of the treatment system. The number of
parameters and sample points is dependent on the type of treatment
required. The frequency of the sampling will depend on the type of
source, its variability of quality, and the importance of the parameter
being evaluated. The following chart illustrates sampling points and
suggested monitored parameters.
8-14
-------
COURSE NOTES FOR UNIT 8
-------
Sampling Points
L_raw water
rapid six
_> flocculatlon
_> seeding
laapla
routine chcalcals
baccaria
jar ce«c
Use <_
chlorlnaclon <_
rouclna chealcala
bacetrla
«aapla
turbidity
alkalinity
filtration <_
turbidity
alkalinity
pH
Routine Analysis;
color iron alkalinity chlocid
turbidity manganese pH fluorid
odor hardness nitrogen series
8-16
-------
COURSE NOTES FOR UNIT 8
-------
SAMPLING
Since the intent of the Safe Drinking Water Act is to insure drinking wate
quality, meaningful analysis of the water is necessary to gauge compliance with
established water quality standards. The analysis of water samples is meaningft
only if three important factors are" followed:
1. The sample collected must be truly .representative of the water under
consideration.
2. The sample must be collected using the proper sampling equipment and
techniques.
3. Once collected, the sample must be protected and preserved until it is
analyzed.
A wide variety of potential sample locations are associated with public
water systems, and specialized sampling techniques must be used on many of these
Common Sample Location:
Source Water Sampling
Surface Water (Streams, Lakes, Reservoirs,
Rivers)
Groundvater
In-Plant Sampling
Raw water
Mixed water
Settled water
Filtered water
Finished water
Distribution System Sampling
Mains
Storage Tanks
Customer tap
.The diversity of sample collection equipment and procedures necessary to
allow sampling of the locations listed above is substantial. Equipment ranging
from simple glass or plastic containers to composite samplers or continuous
monitors are often necessary for the proper evaluation of water quality.
Inspectors should become familiar with the availability and use of sampling
equipment and specifically with their own state's requirement concerning sample
volume requirements, holding times, preservation techniques, reporting and chain
of custody procedures.
Recommendation for Sampling and Preservation of Samples According
to Measurement:
Table 8-2 provides a complete listing or recommendations for
sampling and preservation of samples according to measurement.
Table reprinted from Water Treatment Plant Operation, Volume I,
page 489. Table 8-3 provides the sampling requirements for
microbiological examination of potable water as established by
the South Carolina Department of Health and Environmental Control.
8-18
-------
COURSE NOTES FOR UNIT 8
-------
TABLE 8-2 RECOMMENDATION FOH SAMPLING AND PRESERVATION OF SAMPLES ACCORDING TO MEASUREME.NT»
Measurement
PHYSICAL PROPERTIES
Color
Conductanca
Harcnessd
Odor
pr-f*
Residue. FifteraWe
Tamc-eranjre
Turbidity
METALS (Fe. Mn>
Dissolved
Suspended
Total
INORGANICS, NON-METALLJCS
Acdity
Alkalinity
Bromide
Chloride
CMonne
Cyanide
Fluoride
Iodide
Nitrogen
Ammonia
Kjeidanl. Total
Nitrate plus Nitnte
Nitrate
Nitme
Dissolved Oxygen
Prooe
Winklar.
Phospnorua
Ortno-onosprate. Dissolved
Hydrotyzable
Total
Total, Dissolved
Sinca
Suifate
Suifide
Suifiie
vol.
Req.
(mi.)
50
100
100
200
25
100
1000
100
200
200
100
100
100
100
50
200
500
300
100
400
500
100
100
50
300
300
50
50
SO
50
50
50
500
50
Container0
P.G
P.G
P.G
G only
P.G
P.G
P.G
P.G
P.G
P,G
P,G
P.G
P.G
P.G
P.G
P.G
P.G
P.G
P.G
P.G
P,G
P.G
P.G
G only
G only
P.G
P.G
P.G
P.G
P only
P.G
P.G
P.G
Preservative
Cool, 4'C
Cool, 4'C
Cool. 4'C
HNO, to pH <2
Cool, 4'C
Det on site
Cool. 4'C
Oat on site
Cool. 4'C
Filter on site
HNCj to pH <2
Filter on site
HNOj to pH <2
Cool, 4'C
Cool, 4'C
None Req.
None fleq.
bet. on site
Cool. 4-C
NaOH to pH 12
None fleq.
Cool, 4'C.
Cool. 4'C
HjSO, to pH <2
Cool. 4'C
HjSO, to pH <2
Cool. 4'C
H2SO« to pH <2
Cool. 4'C
Cool. 4'C
Oet. on site
Fix on site
Filter on site
Cool. 4'C
Cool. 4'C
HjSO, to pM <2
Cool. 4'C
HjSOi to pH <2
Filter on site
Cool. 4'C
HjS04 to pH <2
Cool. 4'C
Cool, 4-C
Cool. 4'C
2 mC zinc acetate
Cool, ij-C
Maximi
HnlHtn
ngigin
Tim»i
•*8 hflurt
23 days
6 done*!'
2< hours
2 hourj
14 days
ImrriQdisi
48 hours
S montnj
6 rnontftj
S montfij
U days
14 days
28 days-
23 days
2 hours
14 days
23 days
24 hours
28 days
23 days
28 days.
48 hours
43 hours
1 hour
8 hours
24 hours
24 hours
28 days
24 hours
28 days
28 days
28 day*
48 hours
"•Guidelines Establishing Test Procedures for me Analysis o» Pollutants;' Proposed Regulations: Correction. by U.S. ^"""l
Protection Agency. Federal Register. Pan IV. Vol.
-------
COURSE NOTES FOR UNIT 8
-------
IABLE: 8-3
MICROBIOLOGICAL EXAMINATION OF POTABLE WATER
Tvpe of Examination
1. Total Colifonn
(MF or MPN)
2. Fecal Coliform
(MFC or MPN)
Amount of
Sample Seeded Procedure
4 oz. Analyze within a 30-hour
time limit.
4 oz. Sample refrigerated and
delivered to lab within
6 hours. In no case will ,
sample be analyzed if more
than 30 hours old.
Time Reqd
Completin
MF : 24 ho
Verificat
Additio:
96 hour
MPN: up ti
MFC: 24 hi
Vericatioi
Additioi
72 hour!
MPN: up t<
3. Standard Plate
Count
4 oz.
Sample refrigerated and
examined within a 30-hour
time limit.
48 hours
4. Non-Coiiform
Identification
4 oz.
Collect sample for routine Minimum of
Total CoIiform and request up to 2-3
NCG-ID.
5. Salmonella-Shigella
1-2 liters Sample refrigerated and. 1 week min
delivered to lab within possibly 2
6 hours. Collect only if for confir
Fecal Colifonn is positive.
6. Actinomycetes
4 oz.
Sample collected from raw
water source from a site
near intake to water plant
and as close to the
bottom as possible.
7 days
7- Fungi
4 oz.
Sample refrigerated and 5-7 days
analyzed within 24 hours.,
8. Iron Bacteria
4 oz.
Analyze within a 30-hour
time limit.
24 hours
9. Giardia lamblla
5-10 liters
(500 gal.
preferred)
Preferred method: In-line
filter left in place for
24 hours.
10. Viruses
Minimum of 100
liters Potable
water: 1000
liters
Must be collected by Lab
personnel using cartridge
filter adsorption elation
procedure.
Must be pet
in co-ordiii
with EPA LJ
tories. Cd
3-6 week fd
pletion.
8-22
-------
COURSE iMOTES FOR UNIT 6
-------
Sanitary Risks:
The questions that a surveyor should ask regarding sampling are:
1. Is the operator collecting water samples at the proper location?
The results of the analytical test will be meaningless unless the
water tested is truly representative of the water In question,
2. Are the proper precautions being taken during sampling to provide
valid and useful results? The evaluation of proper techniques
Including the use of proper sampling equipment, preservation
techniques, reporting, and the actual analytical test should be
made.
3. What type of samples should be collected by the person conducting
the survey for analysis by the State Laboratory? Dependent upon
the type of treatment, efficiency of treatment operation and past
water quality results, the Inspector should be ready to collect
the appropriate samples to Insure proper operation and water
quality at the facility. These samples should preferably be spill
with the utility or at least compared with recent results obtalnei
from the. water systems own monitoring.
4. Are the samples being collected under the proper conditions? Is
the operator collecting settled water samples first thing In the
morning following startup? Are samples collected first thing In
the morning following startup for chlorine residual monitoring?
If so, from where are they collected and are they truly
representative? Are sample pumps left running? If not, Is
sufficient flushing time allowed?
5. Is the water system collecting the proper types of samples for the
type of treatment employed? Is the frequency sufficient? A
review of reference material as well as common sense Is necessary
In evaluating a system's monitoring requirements. If a system Is
treating to remove "something", then that "something" generally
should be monitored. If a system is adding a chemical, then
generally that chemical or effect should be monitored.
8-24
-------
COURSE NOTES FOR UNIT 8
-------
Problem Solving Exercises:
The following four (4) problem examples should be evaluated by
groups. Each group should list what sampling they feel should be
conducted and any other items or actions that they feel are needed to
solve the stated problems.
Exaaple #1:
The town of Leptothrix has two deep wells providing
approximately 250 gpm each, a 150,000 gallon elevated tank and a
distribution system serving the town. The groundwater has the
following characteristics:
pH 5.2 - 5.4
Alkalinity 24 mg/1 as CaCo 3
Iron 4.2 mg/1
Manganese 0.37 mg/1
Color less than 15
Hardness 50 mg/1 as CaCo 3
Turbidity 2.5 NTU
The system provides iron and manganese removal treatment by
using a manganese greensand filter. Prechlorlnation, Pre pH
adjustment, and the continuous pre feed of KMnC>4 is the only chemical
treatment.
Problems
Numerous complaints have been received concerning rusty
discolored water which smells bad. What type of samples and from
where would you collect them to ascertain the problem?
8-26
-------
COURSE NOTES FOR UNIT 8
-------
Example f2:
A 40 MGD conventional surface water treatment facility is located on a
shallow reservior that was constructed six (6) years ago. The plant has
experienced problems with manganese as high as 2.2 mg/1 in their raw water and
has had THM quarterly averages as high as 285 mg/1. In order to treat for
manganese and to control the formation of THM's, the facility switched from
pre-chlorintion to chlorination on top of the filters. They also implemented t
feeding of KMnO, into their raw water line near the raw water pumping station.
Problea:
Within the last two weeks the facility has begun to receive numerous
complaints concerning discolored water. What type of samples would you collect
and from where to determine what may be causing this problem and to be able to
prescribe a solution? With this type of treatment change, what monitoring
requirements do you feel would be necessary?
8-28
-------
COURSE NOTES FOR UNIT 8
-------
Example 13:
A small subdivision is served by a private water utility. The operator of
the system says they utilize five (5) low capacity wells (less than 30 gpm each)
and provide disinfection by means of a hypochlorinator and a solution of calciun
hypochlorite as the disinfectant at three (3) of the wells. The system is
diagramed on the next page.
Probleu:
The local Medical Director calls and says he is aware of approximately five
families who are having gastrointestinal problems and that they live in the same
subdivision. After further investigation, you determine that the families are
all on the private water system and that the last 12 months' bacteriological
self-monitoring results were satisfactory. You are requested to perform a
sanitary survey. Upon arrival, you can find no physical reasons that would
indicate an obvious problem at the water system. You, however, discover that thi
sample taker has been collecting all of the required monthly bacteriological
water samples from the tank located at well #5. What samples would you collect
and from where? NOTE: Your Medical Director has just indicated that eight (8)
more G. I. cases have been confirmed and that they too live in the subdivision.
8-30
-------
COURSE NOTES FOR UNIT 8
-------
Exanple M:
A conventional surface water treatment facility is experiencing difficult
in treating a turbid water. The operator on duty indicates that the chemical
dosages have not been changed since they historically determined the best dose
for their water and that no other dose would be any better. You ask the opera]
to run a sample that you collect from the settled water flume to determine the
turbidity. He accommodates you and says it is 18 NTU. He further-explains- th;
is why they have filters. The filter effluent turbidity is indeed 0.18 NTU. [
however, forgets to tell you, they are reaching a terminal head loss in a little
oyer 8 filter hours.
Problem:
What samples would you collect and analyze to try to ascertain what
improvements could be made and to convince the operator a change in chemical
dosage is necessary?
8-32
-------
COURSE NOTES FOR UNIT 3
-------
SCHEMATIC OF CONVENTIONAL SURFACE WATER TREATMENT FACILITY
RAW WATER
JT03AGE RESERVOIR
FLCC!
8AS1N
LOW LIFT
PUMP OR
BOOSTER
CLEAR WELL OR
TREATED WATER
STORAGE TANK
Figure 8-1
-------
COURSE NOTES FOR UNIT 8
-------
SCHEMATIC OF IRON REMOVAL FACILITY
RAW
WATER
V
V
/~
/
OXIDATION
T
Ir i i T3 AT i n w
f 1 L 1 rVM i 1 U IN
1
I
STH 9 4. r ?
1 UKMUt
I
SAMPLE JAMPLE SAMPLE SAMPLE
SAMPLE
Figure 8-2
-------
SCHEMATIC OF GROUNOWATER SYSTEM WITH SIMPLE CHLORINATION
RAW WATER
\
s~
t
CHLORINATION
i
x'
f
STORAGE
\
*
DISTRIBUTION
SAMPLE
SAMPLE SAMPLE
SAMPLE
Figure 8-3
-------
COURSE MOTES FOR UNIT 8
-------
\
\
\
«
\
\
\
%
•\
k
«
*
*
«
\
0
*
4
LEPTOTHRIX. S.C.
*
1 I Tank site with 250 gpm well
2 I 250 gpm well
-------
COURSE NOTES FOR UNIT 8
-------
120 Acre
Reservoir
Note: Raw H20 Intake
has 4 possible intake Levels,
2 ft, 5 ft, 7 ft., 11 ft
Chemical Feed
Q KMnO4
O Lime
(3) Alum
Q C1
NaOH
Sample Locations
DO
m
Rgure 8-5
-------
COURSE NOTES FOR UNIT 6
-------
Well #6
Well #4
1
n
CD
i
D
o
a
n
D
D
D
D
y — v
f" 'V
D
D
Well #3
<. J
n
gal
D
n n ^
D
D
D D
n
JF
U D
D
D
D
D
D 5,000
lank
a a
-
k
D
U
Well
#1
m
We
HI
a
Note: C\ 2 fed only at well #1, #4, and #5.
All wells controlled by pressure switches
-------
COURSE NOTES FOR UNIT 8
-------
UNIT 9
Unit 9: MANAGEMENT/SAFETY
Unit 9a: MANAGEMENT
Unit Summary
Personnel Training/Certification
Personnel Staffing
FlnancIng
Emergency Planning
Unit References
Manual of Water Utility Operations
CChapter 19)
Water Treatment Plant Operation Vol. II
CChapter 23)
Snail Water System Operation & Maintenance
CChapter 3)
Basic Material
The management oŁ the water system does not of itself represent a sanitary
risk to the quality of the water. However, there are several aspects of
management that will affect the overall capabilities of the system.
Personnel
1. Are personnel adequately trained and/or certified?
In order to properly operate a system, personnel must be adequately
trained. This can be provided by an in-house training program
conducted by more experienced personnel. Correspondence courses such
aa Water Treatment Plant Operation, Water Supply System Operation and
AWWA courses are a means for a small system operator to receive
training relatively inexpensively. Operators should also be certified
by the appropriate state regulatory agency. Proof of certification
should be prominently displayed or otherwise made available to the
Inspector.
2. Are there sufficient personnel?
There should be enough personnel to provide for operation during
vacations or sickness as a minimum. The number, of operators is
dependent on the type and size of the treatment process.
finance
3. Are the financing and budget satisfactory?
The system should be able to have sufficient funds for operation,
maintenance, and future replacements.
9-2
-------
COURSE NOTES FOR UNIT 9
-------
Energency^Plannlng
A. The utility should have a contingency plan that outlines what
action will be taken and by whom. The emergency plan should
meet the needs of the facility, the geographical area, and
the nature of the emergency likely to occur. Conditions
such as storms, floods, and civil strife should ba
considered.
9-4
-------
COURSE NOTES FOR UNIT 9
-------
Unit 9bt Safety
Unit Summary
Safety Haza rds
Accident Prevention
Unit References
Manual of Water Utility Operations
CChapter 20)
Manual of Instruction for Water Treatment
Plant Operators C Chapter 19)
Water Distribution System Operation &
Maintenance C Chapter 7)
Small Water System Operation & Maintenance
CChapter 7)
Water Treatment Plant Operation Vol. II
CChapter 20)
Basic Material
Another aspect of management is safety. This is a concern if the system
has 1 operator or 50. It has been pointed out previously that safety
should be a concern of the inspector, both his safety and that of the
operator. There are a number of safety hazards including:
1. Electrical shock
2. Exposure to chemicals
3. Drowning
•4. Working in confined spaces
5. High-intansity noise
6. Sprains and strains due to lifting
7. Slips and fails
The first choice in preventing accidents is to engineer out the exposure.
An example of this is providing guards for all rotating equipment and
belts. This choice is not always possible. The second choice is the use
of protective equipment. The roost frequently used equipment and a
necessity of every plant are the following:
o Safety Helmets - provide protection from falling objects in
manholes and pipe galleries. Can be used as a rceans of
identification.
o Goggles - provide eye protection from chemicals and flying
objects. They rsay need to be supplemented by full face shield when
working with some chemicals.
o Gloves - provide protection against injuries from chemicals and
equipment.
9-6
-------
COURSE NOTES FOR UNIT 9
-------
o Shoes - steel-toed safety shoes provide protection from falling
objects.
o Respirators - protect the wearer from inhalation of dust, organic
vapors, and other chemicals. This equipment is only to be used
where the atmosphere is known not to be oxygen deficient.
o Self-contained Breathing Apparatus - provides protection in oxygen
deficient a-tmospheres where the operator must work, such as
repairing chlorine leaks.
With regard .to safety the inspector should be concerned with
1. Is adequate safety and personal protective equipment provided?
2. Are the facilities free of safety hazards?
9-8
-------
COURSE NOTES FOR UNIT 9
-------
UNIT 10
Unit 10: SURVEYS/SANITARY SURVEY REPORT/FIELD EXERCISE
Unit lOa: Surveys
Unit Summary
On-slte Review
Evaluation Adequacy
File Review
Scheduling Survey
On-slte Inspection
Documenting Observations
Notification of Results
Unit References
How to Conduct a Sanitary Survey
Basic Material
In the previous chapters, the concerns of a sanitary inspector
have been outlined. In this unit a plan for doing the survey
will be developed. As this plan is developed and the use of a
standard form_is discussed, it is important for the inspector to
remember what the purpose of the survey is. The Inspector la to
perform an on-site review of the water source, facilities,
equipment, operation, and maintenance of a public water system
for the purpose of evaluating the adequacy of such source,
facilities, equipment, operation, and maintenance for producing
and distributing safe drinking water. This purpose is easy to
forget and to let the survey become an exercise in completing the
blanks In a particular form. As an inspector, you need to
concentrate on identifying potential or existing problems and
evaluating their risks.
In planning for a survey, an estimate of the time required will
help in managing your schedule. The estimate should include time
prior to, during, and after the survey. Although the time
required will vary with the complexity and the experience of the
inspector, a good rule of thumb would be two days in the office
for every day in the field.
Prior to each survey the inspector should review all available
file information concerning the system being surveyed. This
review will assist you in being fully briefed on the system's
past history and present conditions. Many times, if you are
familiar with the system history, previous inspections, reports,
memorandums, and telephone communications, you can dispel remarks
made concerning previous letters, conversations, etc., that are
taken out of context, altered, or Just misunderstood. This
knowledge of the system's past conveys to th« water system
personnel a concern for the system and professionalism on your
10-2
-------
COURSE NOTES FOR UNIT 10
-------
COURSE NOTES FOR UNIT 10
-------
part. Once the owner, operator, or engineer realizes you are
familiar with their operations and past dealings with your
agency, they will normally take the Inspecting party more seri-
ously and the end result will be better, more accurate> and
useful Information concerning their operation and facilities. Ir
this preparation period, the Initial contact should be establlahe
with the water system. Telephone contact to establish a mutually
acceptable date for t-he on-slte visit Is beneficial. A short
notification letter giving the survey time and date should be
forwarded with instructions for requesting changes to the
schedule. This is also a good opportunity to reiterate the
reasons for performing the survey and to Inform them of specific
Information they will need to provide. This should be provided
In sufficient time for the water system personnel to respond to
the notice. If the Inspector must change the schedule, It must
be done at the earliest possible time. The survey must never be
postponed or. canceled without prior notification.
A brief synopsis of activities during this period follows:
1. Detailed general file review.
2. Detailed review of chemical and bacteriological files.
3. Review self-monitoring reports.
4. Hake contact with owner/operator to establish survey date and
time.
5. Give early notice of any schedule change.
In performing the on-slte survey, the first step Is to be punc-
tual. This will prevent getting off to a bad start because the
operator had to wait.
This brings up the necessity, of the successful survey. Impera-
tive to a successful survey Is having a representative of the
water system, preferably the operator, accompany the Inspector
during the on-slte survey. This will allow the Inspector and
operator to ask questions and develop a mutual confidence In each
other's ability. Once this trust has been developed, the opera-
tor may be more willing to be open about the operations and
problems of the system. This Is the period of evaluating the
system. In most cases it is good to use a standard form to help
the Inspector cover all the points of the system. Again, filling
out a form Is not the primary function of the survey. Many times
system owners and operators are "put off" by someone filling out
a form. They wonder if you know what you are asking or whether
you- are Just filling out a form with information that may never
be used or evaluated. The Inspector should know why each ques-
tion is asked. The Judicious use of • form will Ca} provide
uniformity of Inspections, Cb} ensure completeness of ,the Inspec-
tion by another Inspector, CO facilitate data record, and Cd)
allow followup inspection by another Inspector- There Is no
best form since each system is different and each report must be
10-4
-------
COURSE NOTES FOR UNIT 10
-------
tailored to the specific conditions of that system. There are
several examples of survey forms provided at the end of this
unit. The first Is a compilation of the questions that have be
asked In the previous chapters. Other examples are from the
States of Alaska, South Carolina, Maine, and Missouri. These
examples may be used In developing or comparing your own survey
form.
Some of the activities that should be conducted at this
point follow:
1. Review of system complaints.
2. Review of monthly operator reports and In-house monitoring.
3. Complete Investigation of the water supply, treatment, and
distribution facilities.
4. A general description of the system and a flow diagram.
5. Establishment of an exchange of Information between the
operator and Inspector.
6. Completion of the form as required.
7. Sampling as required.
8. Debriefing of the operator/owner at the end of the
evaluation.
10-6
-------
COURSE NOTES FOR UNIT 10
-------
Unit lObs Sanitary Survey Report
Unit Summary
Purpose
Content
Unit References
How to Conduct a Sanitary Survey
Basic Material
The last phase of the survey la the writing of the report. Thl3
represents the official notification of the results of the evalu-
ation. The report should be done promptly and reflect the Infor-
mation provided to the operator at the end of the on-slte visit.
If the written evaluation Is different from the oral debriefing,
the operator should be advised telephonically of such changes.
There is little that Is more exasperating to the owner/operator
than to receive a written report six months after the on-slte
visit listing deficiencies that he knows nothing about. The
purpose of the report Is Ca) formal notification of deficiencies,
Cb) motivate corrective actloni Cc) provide records of compliance
and future Inspections. The report itself can be as" brief as a
letter or as detailed as necessary to convey to owners and opera-
tors of the system what deficiencies exist and what must be done
to correct them.
The sanitary survey report Is probably the single most Important
item of a sanitary survey. No matter how much research Is con-
ducted or how involved and detailed the field aspects of a sani-
tary survey are, if the findings are not properly registered by
the use of appropriate forms and documented In a sanitary survey
report, then the previous efforts are all but wasted. If formal
documentation and notification of deficiencies are not made fol-
lowing a survey, then It Is very unlikely that the next inspec-
ting party will find any improvement in a system's operation and
maintenance the next time it is surveyed.
Often the Inspector feels that the survey report Is Just a small
and bothersome datall In completing a sanitary survey. No matter
how professional the sanitary survey was and no matter how many
deficiencies were pointed out verbally during your inspection,
the parties receiving the report are not always the ones accompa-
nying the Inspector during the survey, nor are they the ones that
will make the decisions to upgrade or modify the system's opera-
tion. In addition, If properly detailed documentation Is not
registered by the use of sanitary survey forms and a sanitary
survey report. It will be very difficult to use any of the survey
activities for enforcement purposes. If this accurate descrip-
tion of Improper operation or system deficiencies Is not detailed
10-8
-------
COURSE NOTES FOR UNIT 10
-------
In a sanitary report, then the Inspector la guilty of not
fulfilling his responsibilities to the system or the public.
If an accurate and detailed sanitary survey report Is sent In a
timely fashion to the appropriate personnel, then the survey am
the organization will, In most Instances, be construed by the
water system personnel as being professional and will foster
confidence and a wllFlngness to cooperate towards a mutual goaT
safe drinking water.
Briefly, the activities during this period are as follows?
1. Completion of formal report.
2. Notification of appropriate organizations of results.
3. Followup on technical assistance/questions asked by owner/
operator.
4. Notification of variance of written evaluation from that
provided In the oral debriefing.
10-10
-------
CCfURSE NOTES FOR UNIT 10
-------
MAJOR FUNCTIONS OF A SANITARY SURVEY REPORT;
1. To Provide Formal Notification of Deficiencies.
The formal notification of deficiencies speaks for itself. However, by ji
listing the deficiencies, the inspector may not accomplish his objective i
informing the system of a problem and seeking its correction. Often the
inspector assumes operators and water system personnel understand what he
says without questioning whether they actually understand his comments or
even the terminology used. The inspector is often their only contact in
discussing the technical operation of their facilities and it is often
wrongfully assumed that the operators have the ability to fully understand
the inspector's comments. Even if the system personnel understand what tt
inspector wants, it will be quite unlikely that corrective actions will be
taken if they cannot understand the reason for doing it. By taking the ti
to describe the problem in simple terms and by explaining the reasons for
requiring its correction, the inspector will receive a better response.
2. To Motivate Corrective Action.
A sanitary survey report, in addition to verbal communication during the
survey, can be used to motivate corrective actions. This motivation can b>
due to the professional nature of the report, including an explanation of
why corrective actions are necessary. When significant violations exist,
then it is indeed likely that a compliance schedule, consent agreement,
administrative order, or litigation by the appropriate court may be
necessary to ensure prompt and proper correction.
3. To Provide a Record.
The survey report is an important tool for tracking compliance with the Saf
Drinking Water Act, and it is a valuable tool to be used in evaluating you:
water supply program. The single most important feature, however, is the
ability to provide ,a hard record for future inspecting parties and to
provide much needed information during emergency situations or when
technical assistance is needed.
10-12
-------
COURSE NOTES FOR UNIT 10
-------
Unit lOc: Field Exercise
Unit Summary
Application of Knowledge
Selection of Water Supply Systems
Team Approach
Recording Observations
Critique of Field Exercise
Basic Material
A field exercise will be organized to provide the opportunity to
apply classroom Instruction and discussion to actual situations an
to provide practice In recognizing potential problem areas. The
field exercise Incorporates the principle of a Class I Sanitary
Survey during the on-slte Inspection of one or more water supply
systems.
The water supply systems are selected to reflect the size and type
of water systems which are typical In that area. Preference Is al
given to selecting systems which have problems.
Course participants are assigned to teams to ensure a mix of
experience and geography. Discussion between the team members Is
encouraged to Increase the sharing of knowledged between team
members.
As the on-slte Inspection Is conducted, te-am members record their
observations and evaluations on a standard field exercise form
CFlgures 10-1 through 10-4}.
At the conclusion of the field exercise each team is requested to
describe their observations and to explain wnat was right or wrong
in each case. Team members are encouraged to comment during the
discussions and to contribute their own experiences.
10-14
-------
COURSE NOTES FOR UNIT 10
-------
FIELD TRAINING FORM
Date of Survey
Name of System:
Owner:
Address:
Service Connections
Population
System Capacity
Telephone:
Emergency Connections
MGD
S U N/A
Surface Water Source
Source Name(s)
Type
Intake, (location, levels, screens, maintenance)
Access (restricted, monitored)
Pollution Control
Water Quality
Quantity
Low Service. Pumps (number, capacity, condition)
SPRINGS/INFILTRATION GALLERIES
Recharge area protection
Site protection
Flood protection
Construction
Maintenance
Quantity
Quality
1
Figure 10-la
-------
COURSE NOTES FOR UNIT 10
-------
^
o
M/A
WELL
Quantity
Quality (bacti., chem., rad.)
Protection from contamination (pad, seal, casing, vent, location, etc.
Security (fence, lock, etc.)
Wellhead piping (check valve, blowoff, sample tap, gate valve)
Weather protection
Flow measuring device
WATER TREATMENT (UNIT PROCESSES)
Pretreatment
Rapid Mix
Flocculation
Sedimentation
Clarification
Filtration
WATER TREATMENT (GENERAL)
Equipment operation & maintenance (feeders, pumps, filters, etc.)
Gas chlorine compartment
Adequate chlorine residual
Safety equipment & procedures
Chemical usage, feed rates, records
Chemical Storage
Chemical injection point, sample tap
Figure 10-lb
-------
COURSE-NOTES FOR UNIT 10
-------
N/A
STORAGE
Sanitary protection (vents, overflow, drain, etc.)
Maintenance
Security
Adequate volume (total storage
Bypass, drain, sample tap
Air/water ratio (pneumatic)
DISTRIBUTION
^
High service pumps
Booster pumps
Adequate pressure (25 psi min)
Water quality
Fire flow
Valve maintenance (exercise, testing, repair)
Hydrant maintenance
Flushing program
Leak detection & repair
System map
Crossconnection program
Are all services metered?
Yes No
# metered
Figure 10-lc
-------
COURSE NOTES FOR UNIT 10
-------
s
1
M/A
GENERAL OPERATION & MAINTENANCE
Housekeeping
Certified operator
Staffing
O & M records
Supplies & spare parts inventory
Self monitoring reporting records, public notification
Wastewater disposal method:
O & M procedures manual
OPERATOR QUALITY CONTROL
Knowledge & ability
Facilities & test equipment
Daily testing
Records
EMERGENCY OPERATION
Stand-by power
Emergency operation plan
Type Inspection:
Routine:
Follow-up:
Complaint:
Other:
Follow Up: Yes _
Date
No
Overall Rating: Satisfactory
Unsatisfactory
Figure 10-ld
-------
COURSE NOTES FOR UNIT 10
-------
SURVEY SAMPLE FORM
Date of Survey
Name of Facility System Identification
Owner _____ Telephone
Address -
County
Treatment Plant Telephone Number
Name of Operator ________________________ Certification
Water Purchased From Water Sold To
(other than system)
SOURCE
1. What type of source?
2. What is the total design production capacity? MGD
3. Whatsis the present average daily production? MGD
4. What is the maximum daily production? MGD
5. Does system have an operational master meter? Yes No
6. How many service connections are there? ________
7. Are service connections raetered? Yes _____ No
WELLS Yes No
1. Is recharge area protected?
Ownership Fencing ______ Ordinances
2. What is nature of recharge zones?
Agricultural industrial Residential Other
3. Is site subject to flooding?
4. Is well located in.proximity of a potential source of
pollution?
5. Depth of well ft.
6. Drawdown ft.
7. Depth of casing ft.
Figure 10-2a
-------
COURSE MOTES FOR UNIT 10
-------
Yes No
8. Depth of grout ft.
9. Does casing extend at least 12 inches above .the-
floor or ground? ,
10. Is well properly sealed? _____
11. Does well vent terminate 18 inches above ground/floor
level or above maximum flood level with return bend
facing downward and screened? _____ .
12. Does well have suitable sampling cock? _____
13. Are check valves, blowoff valves, and water meters
maintained and operating properly?
14. Is upper termination of well protected?
15. is lightning protection provided? _____
16. Is intake located below the maximum drawdown? _____ ___
17. Are foot valves and/or check valves accessible for
cleaning? ____ ___
" "~ ' Yes No"
SPRINGS AND INFILTRATION GALLERIES
1. is the recharge area protected?
Ownership Fencing _____ Ordinances _____
2. What is the nature of the recharge area?
Agricultural ___ Industrial ____ Residential Other __,
3. Is site subject to flooding?
4. Is collection chamber properly constructed? _____
5. Is supply intake adequate? >
6. Is site properly protected?
7. What conditions cause changes to quality of the
water?
Figure 10-2b
-------
COURSE NOTES FOR UNIT 10
-------
Yes No
SURFACE SOURCES
1. What is nature of watershed?
Agricultural Industrial Forest Residential
2. What is size of the owned/protected area of the watershed?
3. How is watershed controlled?
Ownership Ordinances Zoning
4. Has management had a watershed survey performed?
5. Is there an emergency spill response plan? _____
6. Is the source adequate in quantity?
7. Is the source adequate in quality? ____
8. Is there any treatment provided in the reservoir? .,
9. Is the area around the intake restricted for a radius of
200 feet?
10. Are there any sources of pollution in the proximity
of the intakes?
11. Are multiple intakes, located at different levels,
utilized?
12. la the highest quality water being drawn? _____
13. How often are intakes inspected? _______________________
14. What conditions cause fluctuations in quality?
POMPS
1. Number
Type
Location
2. Rated Capacity
Figure 10-2c
-------
COURSE NOTES FOR UNIT 10
-------
Yes
3. Are pumps operable?
4. What is state of repair of pumps?
5. What type q.f lubricant is used?
6. Emergency power
o What type
o Frequency of testing
o Record of primary power failures: in
last year.
o Automatic Manual Switchover
o Are backup pumps/motors provided?
7. Is all electro/mechanical rotating equipment provided
with guards?
8. Are controls functioning properly and adequately
protected?
9. Are underground compartments and suction well waterproof?
1Q. Are permanently mounted ladders for pumping stations
sound and firmly anchored?
lie Is facility properly protected against trespassing
and vandalism?
Yes No
TREATMENT UNITS (Note: Multiple units should have a separate information
section completed for each unit.)
Prechlorination/Pretreatment Units
1. What chemical is used?
2. What amount is used? __ Ibs/day
3. For prechlorination, has TTHM been evaluated?
4. Where is point of application?
5. Is chemical storage adequate and safe?
6. Are adequate safety devices available and precautions
observed?
Figure 10-2d
-------
COURSE NOTES FOR UNIT 10
-------
Yes NO
Mixing
1. Is mixing adequate based on visual observation?
2. Is equipment operated properly and in good repair? __^
Flocculation/Sedimentation
1. Is process adequate based on visual observation?
2. Is equipment operated properly and in good repair?
Filtration
1. Is process adequate based on visual observation?
2. Are instrumentation and controls for the process adequate,
operational, and being utilized?
3. What type of filter is utilized?
4. Is equipment operated properly and in good repair?
Post-Chlor ination
I* Is adequate chlorine residual being monitored?
2. Is the disinfection equipment being operated and
maintained properly?
3. 13 there sufficient contact time (30 minutes minimum)
between the chlorination point and the first point of
use?
4. Is operational standby equipment provided? If not,
are critical spare parts on hand?
5. Is a manifold provided to allow feeding gas from more
than one cylinder?
6. Are scales provided for weighing of containers?
7. Are chlorine storage and use areas isolated from
other work areas?
9. Is room vented to the outdoors by exhaust grilles
located not more than 6 inches above the floor level?
9. Is a means of leak detection provided?
Figure 10-2e
-------
COURSE MOTES FOR UNIT 10
-------
Yes NO
10. Is self-contained breathing apparatus available for
use during repair of leaks?
11. Are all doors hinged outward, equipped with panic
bars, and at least one provided with a viewport?
12. Are all gas cylinders restrained by chaining to
wall or by other means?
12. Have there been any interruptions in chlorination
during the past year due to chlorinator failure
or feed pump failure?
Yes No
STORAGE
1. What type of,water is stored?
Raw Treated
2. What type of storage is provided?
Gravity gala. Hydropneumatic gals.
3. Total number of days of supply? days
Gravity Storage
1. Does surface runoff and underground drainage drain
away?
2. Is the site protected against flooding?
3. Is storage tank structurally sound?
4. Are overflow lines, air vents, drainage lines or
cleanout pipes turned downward or covered, screened, and
terminated a minimum of 3 diameters above the ground or
storage tank surface?
5. Is site adequately protected against vandalism?
6. Are surface coatings in contact with water approved?
7. is tank protected against icing and corrosion?
9. Can tank be isolated from system?
9. la. all treated water storage covered?
10. What is cleaning frequency for tanks? •
11. Are tanks disinfected after repairs are made?
Figure 10-2f
-------
COURSE NOTES FOR UNIT 10
-------
Yes NO
Hydropneumatic
1. Does low pressure level provide adequate pressure?
2. Axe instruments and controls adequate, operational,
and being utilized?
3. Are the interior and exterior surfaces of the pressure
tank in good physical condition?
4. Are tank supports structurally sound?
5. Is storage capacity adequate? _____
6. What is cycle rate?
Yes NO
DISTRIBUTION SYSTEM
1. Is proper pressure maintained throughout the system?
2. What types of construction materials are used?
3. Are plans of the water system available and current?
4. Does the utility have an adequate maintenance program?
5. Is the system interconnected with any other system? _____
YesNO"
CaOSS-CONHECTIONS
1. Does the utility have a cross-connection prevention
program?
2* Are backflow prevention devices installed at all
appropriate locations? ______
3. Are cross-connections present at th« treatment plant?
YesNo"
MONITORING
1. Is the operator competent in performing necessary tests? _____
2. Are testing facilities and equipment adequate? ______ __
Figure 10-2g
-------
COURSE NOTES FOR UNIT 10
-------
Yes NO
3. Do reagents used have an unexpired shelf life? .
4. Are records of test results being maintained?
Yes NO
MANAGEMENT
1. Are personnel adequately trained?
2. Are operators properly certified?
3. Are there sufficient personnel? _____
4. Are financing and budget satisfactory? _____
5. Is an emergency plan available and workable?
6. Is adequate safety and personal protective equipment
provided? _____
7. Are the facilities free of safety hazards?
Figure 10-2h
-------
COURSE NOTES FOR UNIT 10
-------
SITE PLAN
TREATMENT UNIT SCHEMATIC
Figure 10-21
-------
COURSE NOTES FOR UNIT 11
-------
UNIT 11
Unit 11: Communications/Public Relations
Unit Summary
Personal Contacts and Purpose
Communicating Effectively
Unit References
Water Distribution System Operation and
Maintenance CChapter 5) >
Water Treatment Plant Operation Vol. I
CChapter
Basic Material
An area that the Inspector of a water system must deal with Is
who to contact with regard to the sanitary survey. This contact
Is necessary for obtaining cooperation, gathering Information!
coordinating with other departments or agencies, and transmitting
the results of the evaluation. Briefly, the parsons/agencies the
Inspector should contact, and the purpose of the contact, are the
following:
Prior to On-slte Visit
Owner of water system
Obtain cooperation and establish survey dates
Explain purposes of survey
Request that necessary Information be available
Operator
Coordinate gaining entry to site
Ensure presence of operator during survey
Local Health Unit/Other Departments
Ensure cooperation and coordination
Obtain information pertinent to system
Durlng_thQ_Qn-aita_Vialt
Owner of water system
Obtain Information pertinent to system
Explain function of survey results
Explain recommended actions
Explain what action will result from survey
Operator
Obtain Information pertinent to system
Exchange of technical Information
Explain survey results
Explain recommended action
11-2
-------
COURSE NOTES FOR UNIT 11
-------
After the On-3lte Visit CSurvey Report)
Owner of water system
Notification of deficiencies
Instructions for corrections
Compliance schedule for corrections
State Regulatory Agency
Case report where formal enforcement Is Indicated
U.S. Environmental Protection Agency
Case report when State does not have primacy under
SDWA
Public
If system Is not In compliance with:
applicable MCL
applicable testing procedure
required monitoring
scheduled corrections
an exemption or variance
Brleflyt we need to discuss communications with the owner/
operator and with the public. There Is not sufficient time In
this course to fully discuss Interpersonal relationships and how
to deal with people. .However, there are some points that Inspec
tors should keep in mind. The establishment of a good relation-
ship with the operator la important to the success of the survey
The operator of the small water system occupies a unique posltlo
In the water supply Industry. In most cases the operator Is
responsible for all aspects of the system from operation of the
plant to budgeting for equipment and in small towns may also be
responsible for the other services Cwastewater treatment, road
repair, etc.) in the community. Consequently, the operator will
frequently have only a basic working knowledge of the treatment
processes of that particular system. The fact that the operator
may not be fully knowledgeable about the technical design cri-
teria does not make the operator Incompetent. Communicate with
the operator in terms that can be understood, not by yourself or
by an engineer, but by the operator- This is particularly true
when providing assistance. An in-depth discussion on the
Brownlan movement of colloidal particles may dazzle th« operator
with your brilliance but do little to foster a good relationship
Communicating at the level of your audience is particularly
important In dealing with the general public. A technical know-
ledge of water treatment and water quality cannot be assumed wltl
the general public. Consequently, you must be careful to couch
your communications in layman's terms, particularly when dealing
with problems In the system. The public should be made to real-
ize the Impact of the problem without having the dangers
exaggerated.
11-4
-------
COURSE NOTES FOR UNIT 12
-------
UNIT 12
UNIT 12: TECHNICAL ASSISTANCE
Unit Summary
Providing Technical Assistance
Common Problems
Unit References
Small Water Systems Serving the Public
(Chapter 13)
Handbook of Individual Water Systems
Water Systems Handbook
Water Treatment Plant Operation (Volumes I
& II)
Water Supply System Operation
Basic Material
The sanitary survey is in part designed to assist the water purveyor in
correcting~any deficiencies in water quality or the water supply system.
m order to provide this assistance, the inspector must be able to commun-
icate to water system personnel the possible causes of problems. Problem
solving should be approached in a systematic manner with a concept of the
elements that might contribute to water problems and with insights into
possible solutions.
An effective maintenance and repair schedule is of primary importance in
operating a water supply system. Every opportunity should be taken to
provide guidance in the development of such a system and to supply techni-
cal assistance with potential and actual water system problems.
How the technical assistance is provided is equally important as the in-
formation given. Unless the solution is obvious, technical assistance
should be given only after the entire system has been surveyed. There are
two reasons for this procedure. First, the objective of your visit is to
evaluate the entire water system. If you spend your time playing Sherlock
Holmes in attempting to determine the cause of a problem* you have changed
your objective and may very well overlook a serious sanitary risk, isola-
ting the cause of a water system problem is time consuming and without
sampling and analytical support, generally difficult. If the operator is
competent, the more common causes will have been evaluated and will have
been ruled out. The second reason for surveying the entire system is that
there can be causes of problems throughout the system. Consequently,
judgment should be reserved until the entire system has been reviewed.
12-2
-------
COURSE NOTES FOR UNIT 12
-------
The operator should be asked what steps have been taken to evaluate and
mitigate the problem. The inspector should determine if the problem has
occurred before and what action was taken. A review of operating records
may provide a clue to recent changes in the system or chemicals utilized
that may be the cause.
The inspector -shootd temper any advice with a realization of their
experience and knowledge of the problem. If erroneous information is
provided, a loss of money and time can result while the hazard continues
to exist. The classic "I'm from the Government and I'm here to help"
situation followed by assistance that intensifies the problem rather than
finds a solution can be devastating. The inspector with limited
experience is wiser to refer the problem to more experienced personnel.
Many States have developed a means by which assistance can be provided to
a water system either by its request or a referral from a sanitary
inspector. This is not to say that there should not be an exchange of
technical infocmation with the operator by an inspector. The inspector
should note sanitary problems to the operator, discuss their importance,
and if sure of a means of resolution, provide it.
Review the following problems in light of the possible causes. Wherever
possible, relate the possible causes to indicators of the problem so as to
best aid the water purveyor with any problems. Use the elements of the
system as a checklist of your knowledge.
Problem 1; No or Low Water Pressure
Health Risk
o Contamination from backflow (cross-connection)
Possible Causes;
Water Source
o Water table has dropped below well screen
o Clogging of well screen with debris
o Spring flow has been diminished
Well or Intake Structure
a Debris blocking pipes
o Defective valves or valve settings
o Plugged foot valve or strainer
o Break in wall of collection chamber
o Water in collection chamber or pipes freezing
o Well screen plugged or broken
o Well pipe ruptured above water table (shallow well with suction
pump)
Treatment Equipment
o Electrical safety control activated to cut off water pump due to
inoperative chemical feed pump
12-4
-------
COURSE NOTES FOR UNIT 12
-------
Pump System
o Power failure
o Low line voltage
o Blown fuses
o Shorted-out electric motor
o Defective pressure switch
o' System valved off
o Air lock in suction line
o Leak on suction side of system
o Plugged ejector or impeller
o Worn or defective pump
o Discharge line check valve installed backward
o Loss of prime in piston-type pump
Storage System
o Ruptured tank
o Drain valve open
o Float switches on gravity tank defective
o Pressure switch on hydropneumatic storage tank defective
Distribution System
o Break in water main
o Hydrants open
o Excessive water demand over prolonged period
Problem 2; Water Quality Violates Standards
Health Risk
o Disease or chemical poisoning of consumers
Possible Causesr
Water Source
o Contamination of source by wastewater or toxic chemicals
Well or Intake Situation
o Onsite contamination by wastewater or toxic chemicals
o Inoperative well seal
Treatment Process
o Contamination of treatment chemicals
o Insufficient chlorine feed rate
o Chlorine solution exhausted
o Defective chemicals feed equipment
Pump System
o Repair or replacement of pump parts without adequate disinfection
o Use of contaminated water to lubricate package
o Improper sealing of pump to base during repair
o Improper drainage of pump
12-6
-------
COURSE NOTES FOR UNIT 12
-------
Storage System
o Debris in storage tanks
o Interior of tank coated with unapproved coatings
o Access of contaminants through broken vent or open manhole
Distribution System
o Cross-connection with source of sewage or toxic chemical
Problem 3; The Water Has Bad Taste, Odor, or Color
Health Risk
o Possible bacterial or chemical contamination
o Use by consumer of a more palatable but potentially less safe watt
supply
Possible Causes:
Water Source
o Contamination of source by foreign substance
Well or Intake Structure
6 Entry of contaminant into structure through defective vent, open
manhole, or screen
o Inoperative well seal, allowing entry of contaminant
Treatment Process
o Production of chlorophenyls by action of chlorine on precursor
substances
Pump System
o Repair or replacement of pump parts without adequate disinfection
o Use of contaminated water to lubricate package
o improper sealing of pump to base, allowing entry of contaminants
o Improper drainage of pump
Storage System
o Debris in storage tank
o Interior of tank coated with unapproved coatings
o Entry of contaminants through broken vent or open manhole
Distribution System
o Iron bacteria growth in pipes
12-8
-------
-------
APPENDIX
SUGGESTED REFERENCES
1. Water Treatment Plant Operations, Volume I
Water Treatment Plant Operations, Volume II
Water Distribution System Operation & Maintenance
Small Water System Operation & Maintenance
Available from: Kenneth Kerri
Department of Civil Engineering
California State University, Sacramento
6000 J Street
Sacramento, CA 95810
(Phone: 916-278-6142)
Price: $30.00/$30.00/$20.00/$20.00 per manual, respectively
2. Manual of Water Utility Operations
Available from: Texas Water Utilities Association
6.521 Burnet Lane
Austin, TX 78757
Price: $17.00
3. A Manual of Instruction for Water Treatment Plant Operators
Available from: Health Education Services, Inc.
P.O. Box 7126
Albany, NY 12224
Price: $5.00
4. Planning for an Individual Water System
Available from: American Association for Vocational
Instructional Materials
Engineering Center
Athens, GA 30602
Price: $7.65
5. Water Systems Handbook
Available from: Water Systems Council
221 North LaSalle Street
Chicago, IL 60601
Price: $6.00
6. Environmental Engineering and Sanitation — by Joseph A. Salvato
Available from: John Wiley & Sons, Inc.
Somerset, NJ 08873
Price: $55.00
7. National Interim Primary Drinking Water Regulations
Available from: Superintendent of Documents
U.S. Government Printing Office
Washington, D.C. 20402
Stock No. 055-000-00157-0
Price: $5.50
13-1
-------
-------
SUGGESTED REFERENCES (continued)
8. Manual of Individual Water Supply Systems
Available from: Superintendent of Documents
U.S. Government Printing Office
Washington, D.C. 20402
Stock No. 055-000-00229-1
Price: $6.00
9. How to Conduct a Sanitary Survey Procedures Manual
Available from: New Mexico Health and Environmental Department
Environmental Improvement Division
P.O. Box 968
Santa Fe, NM 87504-0968,
Price: $4.00
10. National Secondary Drinking Water Regulations
Available from: Environmental Protection Agency
Office of Water Supply
Washington, D.C. 20460
EPA-570/9/76-000
11. The Safe Drinking Water Act Handbook for Water System Operators
Available from: AWWA
6666 W. Quincy Avenue
Denver, CO 80235
12. Introduction to Water Sources Transmission, Volume I
Available from: AWWA
666 W. Quincy Avenue
Denver, CO 80235
13. Introduction to Water Treatment, Volume II
Available from: AWWA
6666 W. Quincy Avenue
Denver, CO 80235
14. Introduction to Water Distribution, Volume III
Available from: AWWA
6666 W. Quincy Avenue
Denver, CO 80235
15. Introduction to Water Quality Analyses, Volume IV
Available from: AWWA
6666 W. Quincy Avenue
Denver; CO 80235
16. Basic Science Concepts and Applications Reference Handbook
Available from: AWWA
.6666 W. Quincy Avenue
Denver, CO 80235
13-2
-------
i I'J i sL'Zt
-------
ADDITIONAL READINGS
1. Water Treatment Plant Design, prepared jointly by the American Water Works
Association, Conference of State Sanitary Engineers, and American Society
Civil Engineers
Available from: Data Processing Department, AWWA
6666 W. Quincy Avenue
Denver, CO 80235
Price: To members - $14.40; nonmembers - $18.00
2. Water Quality and Treatment: A Handbook of Public Water Supplies;
American Water Works Association, Third Edition, McGraw-Hill, 1971
Available from: Data Processing Department, AWWA
6666 W. Quincy Avenue
Denver, CO 80235
Order No. 10008
Price: To members - $34.10; nonmembers - $42.60
3. Manual of Treatment Techniques for Meeting the Interim Primary Drinking
Water Regulation; EPA 600/8-77-005
Available from: ORD Publications
USEPA-CERI
26 West St. Clair Street
Cincinnati, OH 45268
Price: Free
AUDIO-VISUAL TRAINING MATERIALS
Films
1. "Anybody Can Do It"
Supplier: Out of Print
2. "Safe Handling of Chlorine:
Supplier: AWWA - Technical Library
6666 W. Quincy Avenue
Denver, CO 80235
(Phone: 303-794-7711)
Slides/Tapes
1. "Safe Handling of Water Treatment Chemicals"
Supplier: AWWA - Technical Library
666 W. Quincy Avenue
Denver, CO 80235
(Phone: 303-794-7711)
Slides of Case Histories
Individual libraries
13-3
------- |