ENVIRONMENTAL PROTECTION AGENCY £. ?.A. :•::•;!•»' 4 '.
"JUL 7 1972
WASHINGTON, D.C. 20460 . .. t PM'7?
JUL
to
Attn of:
Subject: EPA Policy Statement on Water Reuse
To: All Regional Administrators
The Office of Air and Water Programs and the Office of Research
and Monitoring have jointly prepared the attached EPA Policy Statement
on Water Reuse and the accompanying Water Reuse Background Statement.
These documents are for your guidance and for distribution as you
see fit,,
~
Robert I/. Sansom
Assistant Administrator
for Air and Water Programs
Attachment
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EPA POLICY STATEMENT ON WATER REUSE
The demand for water is increasing both through population growth and changing
life styles, while the supply of water from nature remains basically constant
from year to year. This is not to imply that we are or will shortly be out
of water, although water shortages are of great comcern in some regions and
indirect reuse has been common for generations. Vfe must recognize the need
to use and reuse wastewater. Therefore,
1. EPA supports and encourages the continued development and practice
of .successive wastewater reclamation, reuse, recycling and recharge
.as a major element in water resource management, providing the rec-
lamation systems are designed and operated so as to avoid health
hazards to the people or damage to the environment.
2. In particular, EPA recognizes and supports the potential for waste-
water reuse in agriculture, industrial, municipal, recreational and
groundwater recharge applications.
3. EPA does not currently support the direct interconnection of waste-
water reclamation plants with municipal water treatment plants.
The potable use of renovated wastewaters blended with other accep-
table supplies in reservoirs may be employed once research and
demonstration has shown that it can be done without hazard to health.
EPA believes that other factors must also receive consideration, such
as the ecological impact of various alternatives, quality of avail-
able sources, and economics.
4. EPA will continue to support reuse research and demonstration projects
including procedures for the rapid identification and removal of vi-
ruses and organics, epidemiological and toxicological analyses of
effects, advanced waste and drinking water treatment process design
and5operation, development of water quality requirements for various
reuse opportunities, and cost-effectiveness studies.
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WATER REUSE
Background
While indirect and delayed reuse of water has many accepted applications, the
direct application of measures to reuse wastewaters for constructive purposes
presents both new opportunities and new problems. Direct reuse is currently
being conducted in a number of places for specific purposes; in fact, Cali-
fornia reported in 1969 over 200 non-potable reuse situations. Reuse is
being applied for a number of purposes, including industrial use for cooling
purposes, for groundwater recharge to prevent salt water intrusion in coastal
areas; as a source for recreational waters; for irrigation and other agri-
cultural uses, not involving direct contact with food surfaces; and for other
uses. An appendix is included for definition of direct and indirect reuse
and discussion of the differences related thereto.
The potential for water reuse, as a tool in broad water resources and water
quality planning, is many times greater than current practice and should be
routine y considered and developed to meet non-potable demands. As could be
expected, activity with regard to reuse appears to be much intensified in
water-short areas of the country, for instance in the arid West. The Water
Resources Council (WRC) report, "The Nation's Water Resources, 1968" cites
water shortage problems in 9 basins--Arkansas-White-Red; Texas-Gulf; Rio
Grande; Upper Colorado; Souris-Red-Rainy; Missouri; Lower Colorado; Great
Basin; and California—and pointedly shows that these problems will worsen
by 2020 unless remedial measures are applied.
In addition to. reuse of wastewaters, attention is being given to weather
modification, desalination, water conservation, interbasin transfer, tap-
ping of the geothermal deep-water reservoirs and other approaches to con-
serve existing as well as tap new sources. Reuse should be considered in
the light of water quality, environmental, ecological and economic aspects
as well as the public health aspects; it should provide a vital link in
meeting needs in water short areas.
\
>
Reuse Application and Public Health Problems
Taking a national view of fresh water demands, it may be seen from the
1968 WRC report that for 2020, electric power (cooling water) will be
first in demand (410 BCD); self-supplied industrial, second (210 BCD); ir-
rigation, third (161 BCD); and municipal, fourth (74 BCD); with minor residue
demands for livestock and rural domestic. Logically, one would expect that
priorities for reuse would pattern after demand with electric power (cooling)
first, industrial second, etc. Such a pattern of application would ideally
suit health protection-water quality relationships since cooling and most
industrial uses would present low health risks; irrigation for some crops
would be potentially hazardous, but not for others; and municipal uses would
offer the greatest human contact and the largest potential danger.
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The problem may not be handled so simply on gross utilization terms since each
call for water reuse will be situational, depending on geographic location,
climate, public attitudes, the availability of wastewater sources and of po-
tential water users, etc. One community may be non-conservative in utilizing
its fresh waters and be willing to treat and recycle wastewaters in order to
continue its easy-water practices while another community with a similar po-
licy and. an abundant supply of cheap water may be unwilling to treat and re-
cycle wastewater just to conserve water for use by others—for instance for
irrigation or municipal purposes elsewhere. In one case, a needy municipal-
ity may be in a position to utilize, industrial wastewaters and in another
case a needy industry may be situated so as to use municipal wastewaters.
In any event the technology is available for the treatment and reuse of many
wastewaters for many purposes and such reuse should be broadly considered
in the management of water resources.
Public health problems do occur and require attention as follows:
1. Industrial: The reuse of water by industry should be encouraged
where it is technically and economically feasible. Quality needs
for industrial uses vary so widely that it is not possible to
generalize on this subject; however, except for food processing
industries, they are usually lower than drinking water requirements.
2. Groundwater Recharge: Groundwater recharge can be used to raise or
maintain the level of groundwater and/or to prevent the intrusion of
salt water. For most recharge applications through spreading and
percolation of reuse waters on the surface, quality requirements
/ . for health protection would be enhanced by natural filtering pro-
cesses. However, percolation into a shallow basin used for drink-
ing water supply should receive careful attention and the recharge
of reuse water by subsurface injection should not be implemented
without strict controls and a clear demonstration that such dis-
posal will not harm present or potential subsurface water supplies
or otherwise damage the environment.
3. Recreation: Indirect reuse of water for primary contact recrea-
tional purposes is clearly recognized in the section on recreational
uses in Water Quality Criteria by way of the recommended limits for
fecal coliform organisms and the recommendation that sanitary sur-
veys be conducted to determine the degree of threat of pathogens
from specific sources. •'
The hazards associated with direct contact recreation in waters re-
ceiving inadequately treated waste discharges are chiefly biological
and are usually associated with the transmission of infectious di-
seases that may enter the body through the mouth or nasal passages
or other portals such as the eyes, and certain areas of the skin.
Numerous examples may be given of both direct and indirect use of
treated wastewaters for recreational purposes and this appears to be
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a valid practice where health requirements can be met. However,
much remains to te known about the health relationships of water
quality and recreational use. For example, water high in nutrients
may serve as a culture for pathogenic bacteria. Further research
and epidemiological investigations into water quality and health re-
lationships are urgently needed.
4. Irrigation: The reuse of waters for irrigation is and should be a
satisfactory mode of reuse. Water quality requirements for crop
protection relate primarily to salinity and toxic compounds. For
irrigation of non-food or shelled-food crops health considerations
would be minimal but for irrigation of other food crops or of pas-
turage for food-animals, the hazards are significant unless the
water is adequately treated. Much study and development of safe-
guards should precede this latter use. :
5. Municipal: The concurrent use of the Nation's rivers and lakes for
both water supply and waste disposal has been practiced for many
years in many areas of the country. It is estimated that 50% of
the Nation's population now derives their water supply from sur-
face sources which have also received a variety of industrial wastes,
untreated sewage, urban runoff and effluent fron a variety of sewage
treatment plants. Public health officials have relied upon time of
travel or storage and treatment to protect the public against infec-
tious diseases and toxic substances. Water quality standards and
treatment requirements applicable to surface sources used for water
supply have permitted the discharge of relatively high quantities
of wastes. The continuing development of new advanced wastewater
treatment technologies and implementation of.new standards will
necessitate a reappraisal of historical philosophies.
Indirect reuse for municipal public water supply is a fact of life;
however, direct reuse is a new matter requiring careful research and
investigation before introduction. Currently, there is insufficient
data to support safety of direct interconnection of wastewater rec-
lamation plants into municipal water supplies. However, the direct
connection of municipal renovated water to supply industrial water
needs is desirable and should be exploited where practical.
Health problems in a direct interconnection or in a recycling situation re-
late to viruses, bacterial build-up, chemical build-up, the possibility of
accidental spills or sabotage and a record of questionable reliability in
the operation of wastewater treatment plants. Viruses are difficult to
identify and measure and are more resistant to disinfection than bacteria.
Carbon columns and other possible advanced waste treatment elements may har-
bor bacteria or their metabolites and contribute to the development of un-
healthful levels of bacteria in a recycling situation.
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The direct introduction of chemicals from a waste-stream and their build-up
through potable system-waste system recycling can present increased long-
term chronic hazards, presently undefined. Accidental-spills or sabotage
present an acute threat which cannot be disregarded, as anyone can throw any-
thing down the drain. Because of these, even if orher.obiectionable problems
were solved, some system of holding and dilution, reservoirs may inevitably
need to be provided between the reclamation plant and the potable water in-
take together with biological and chemical monitoring. With regard to the
reliability of reclamation plant operation, studies in California have shown
that 60% of wastewater treatment plants studied had some breakdown during the
year. Observations of engineers and others confirm that reliability is a com-
mon problem in wastewater treatment plants; safeguards must be provided to
prevent the introduction of non-treated or poorly treated wastes into a potable
water system.
Conclusions , . .
1. The purposeful reuse of treated wastewaters has a large potential
in helping to meet water supply needs. Expansion of reuse as a
tool of water quality and water resources management should be
encouraged as long as measures are taken to protect the public
health.
2. We do not have the knowledge to support the direct interconnection
of wastewater reclamation plants into municipal water supplies at
this time. The potable use of renovated wastewaters blended with
other acceptable supplies in reservoirs may be employed once re-
search and demonstration has shown that all of the following con-
ditions would be met: ... . ..
a) protection from hazards to health
b) offers higher quality than available conventional sources
c) results in less adverse ecological impact than conventional
alternatives
d) is tested and supplied using completely dependable chemical
and biological control technology
e) is more economical than conventional sources
f) is approved by cognizant public health authorities
3. An accelerated research and demonstration program is vitally needed to:
Develop basic information and remedial measures with respect to •
•viruses, bacteria, chemical build-ups, toxicological aspects and
other health problems. Develop criteria and standards to assure
health protection in connection with reuse.
Upgrade the treatment process design and operation so as to as-
sure continuously safe service to the public. Provide economic
an'd other analyses to facilitate the planning and design of ef-
fective regional solutions to problems of water-shortage and
water quality.
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\J Water Quality Criteria, Report of the National Technical Advisory
- Committee to the Secretary of the Interior, April 1, 1968.
2j Ongerth, H.J., Jopling, W.F., and Deaner, D.G. Fitness Needs for
Wastewater Reclamation Plants, J. American Water Works Assn., Oct., 1971,
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APPENDIX: . DEFINITIONS AND DISCUSSION OF DIFFERENCES
FOR DIRECT AND INDIRECT REUSE
Definitions are derived from a report of the National Water Commission,
"Wastewater Reuse," by Jerome Gavis, July 1971, as follows:
1. Direct Reuse: is the direct routing of treated wastewater
effluents to the point of use.
2. Indirect Reuse: is the discharge of treated wastewater where
it is subjected to natural purification processes and dilution
before being withdrawn for use.
Differences in the two types of reuse that must be considered in any
drinking water application are as follows:
1„ Direct reuse is more vulnerable to sabotage, operational
failure and the accidental spill of toxic or hazardous sub-
stances into the water-wastewater system. The provision of
fail-safe equipment, processes and holding reservoirs may be
necessary to meet this problem.
2. Direct reuse allows no margin for error in the destruction
of pathogenic viruses, bacteria and other microorganisms.
v*> '• ,
3o Direct reuse could result in the buildup of trace substances
to many times their usual concentration; 'depending on the
degree of reuse and the efficiency of treatment, the con-
centration factor could run up to nine times.
Many of the factors influencing direct reuse may come into play for
indirect reuse. If the time and dilution factors before indirect
reuse are small, the impacts of dilution and natural purification
may be minimal. Yet the question of what time and dilution factors
are adequate cannot be answered on the basis of today's knowledge.
Research to acquire new basic knowledge and common sense in the
application of today's limited knowledge is essential. Also, it
is essential that each reuse situation be treated on an individual
basis, taking into account all factors.
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