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EPA-600/9-75-007
December 1975
RESEARCH NEEDS
FOR THE
POTABLE REUSE OF MUNICIPAL WASTEWATER
Proceedings of a Workshop
Sponsored by the:
U.S. Environmental Protection Agency
American Water Works Association
Water Pollution Control Federation
in cooperation with the
University of Colorado
March 17-20, 1975, Boulder, Colorado
Edited By:
K. Daniel Linstedt
Edwin R. Bennett
University of Colorado
Research Grant No. R803546
Project Officer'
John N. English
Wastewater Research Division
Municipal Environmental Research Laboratory
Cincinnati, Ohio 45268
MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Municipal Environmental Research Laboratory,
U.S. Environmental Protection Agency, and approved for publication. Approval
does not signify that the contents necessarily reflect the views and policies
of the U.S. Environmental Protection Agency, nor does mention of trade names
or commercial products constitute endorsement or recommendation for use.
ii
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FOREWORD
Man and his environment must be protected from the adverse effects of pesti-
cides, radiation, noise, and other forms of pollution, and the unwise manage-
ment of solid waste. Efforts to protect the environment require a focus that
recognizes the interplay between the components of our physical environment
air, water, and land. The Municipal Environmental Research Laboratory contributes
to this multidisciplinary focus through programs engaged in
• studies on the effects of environmental contaminants on
the biosphere, and
• a search for ways to prevent contamination and to recycle
valuable resources
This Proceedings contains the results of a Workshop that was held to identify
research needs for the reuse of municipal wastewater for potable purposes.
Identification of needed research is a necessary first step in developing the
technology to recycle resources and protect the environment.
iii
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ORGANIZING COMMITTEE
CHAIRMAN
F. M. Middleton
Environmental Protection Agency
CO-CHAIRMAN CO-CHAIRMAN
E. R. Bennett K- D. Linstedt
University of Colorado University of Colorado
Water Pollution Control Federation
MEMBERS
C. A. Brunner, Environmental Protection Agency
J. J. Convery, Environmental Protection Agency
J. N. English, Environmental Protection Agency
G. G. Robeck, Environmental Protection Agency
J. M. Smith, Environmental Protection Agency
E. F. Spitzer, American Water Works Association
P. Tobin, Environmental Protection Agency
iv
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PREFACE
Water reuse is not a new concept In
that it has been practiced for many years
for such non-potable uses as irrigation,
recreation, and industrial purposes.
However, it has recently become apparent
that sound management of water resources
must include consideration of the poten-
tial for indirect or direct reuse of high
quality treated wastewaters as part of
domestic supply waters. Where water
development costs and legal constraints
are making sources of raw water difficult
to acquire, wastewater reuse is increas-
ingly being considered as a potential
alternative water source. While present
treatment technology has proven adequate
to provide a suitable product water qual-
ity for many of the non-potable reuse
applications, this is certainly not the
case for domestic wastewater reuse.
Additional research is necessary before
direct potable reuse can be permitted.
The Water Pollution Control Federa-
tion and the American Water Works Asso-
ciation recently issued a joint resolution
that urged the Federal government to
support a massive research effort to
develop needed technology and evaluate
potential health problems related to re-
cycling of wastewaters to domestic water
supplies. These organizations under-
scored the "lack of adequate scientific
information about possible acute and
long-term effects on man's health from
such reuse," and also noted that "the
essential fail-safe technology to permit
such direct reuse has not yet been
demonstrated." The resolution iden-
tified the need for an "immediate and
sustained multidisciplinary, national
effort to provide the scientific know-
ledge and technology relative to the
reuse of water for drinking purposes in
order to assure the full protection of
the public health."
Public Law 92-500, the "Federal
Water Pollution Control Act Amendments
of 1972," recognized the potentially
large benefit to be realized if waste-
waters can be renovated for reuse
applications. It authorized EPA to
make grants for demonstrating advanced
waste treatment and water purification
methods, and required that the Adminis-
trator conduct an accelerated effort to
develop, refine and achieve practical
application of advanced waste treatment
methods for reclaiming and recycling
water.
Likewise, the new Safe Drinking Water
Act also contained mandates of impor-
tance with regard to renovation and re-
cycling of wastewaters. Specifically, it
authorized a development and demonstra-
tion program to (1) demonstrate new or
improved technology for providing safe
water supply to both urban and rural
areas, and (2) to investigate and demon-
strate health implications involved in
the reclamation, recycling, and reuse of
wastewaters for drinking and related uses,
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and to demonstrate processes and methods
for the safe and aesthetic preparation of
such waters. There exists, therefore, a
strong and clear mandate for research,
development, and demonstration of reliable,
cost-effective technology for reclaiming
and recycling wastewaters for beneficial
uses.
The Research Needs workshop which is
summarized in this document represents an
initial step in the formulation of a
unified research program aimed at develop-
ing confidence in potable reuse of waste
water. The workshop was jointly sponsored
by the United States Environmental Pro-
tection Agency, American Water Works
Association, and the Water Pollution
Control Federation, and was held on March
17-20, 1975, in Boulder, Colorado. It
has provided a forum for assembling
specific input relative to the wide range
of research needs associated with potable
reuse. We trust that this input will lead
to the development of a coherent and
effective research effort on domestic
wastewater reuse.
K. Daniel Linstedt
Cochairman, Municipal
Wastewater Reuse
Research Needs Workshop
Edwin R. Bennett
Cochairman, Municipal
Wastewater Reuse
Research Needs Workshop
John N. English, Member
Organizing Committee
Municipal Wastewater
Reuse Research Needs
Workshop
vi
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CONTENTS
Page
PREFACE v
ORGANIZING COMMITTEE ix
SUMMARY 1
WORKSHOP OBJECTIVES 4
Donald P. DuBois, Environmental Protection Agency
OVERVIEW OF WASTEWATER REUSE AND EPA RESEARCH STRATEGY 6
F- M. Middleton, Environmental Protection Agency
CURRENT MUNICIPAL WASTEWATER REUSE PRACTICES 15
C. J. Schmidt, SCS Engineers
WASTEWATER REUSE IN ORANGE COUNTY, CALIFORNIA 29
Neil M. Cline and David G. Argo, Orange County Water District
WASTEWATER REUSE AS A WATER RESOURCE - THE DENVER EXPERIENCE 60
J. L. Ogilvie, Denver Water Department
WASTEWATER TREATMENT TECHNOLOGY FOR POTABLE REUSE 67
R. B. Dean and J. J. Convery, Environmental Protection Agency
TREATMENT RELIABILITY AND EFFLUENT QUALITY CONTROL FOR 78
POTABLE REUSE
H. J. Ongerth and J. Crook, California State Department
of Health
HEALTH ASPECTS OF REUSING WASTEWATER FOR POTABLE PURPOSES - 86
U.S. EXPERIENCE
L. J. McCabe, Environmental Protection Agency
EVALUATION OF THE HEALTH ASPECTS OF REUSING WASTEWATER FOR 97
POTABLE PURPOSES IN ISRAEL
H. I. Shuval, Hebrew University, Jerusalem, Israel
HEALTH ASPECTS OF REUSING WASTEWATER FOR POTABLE PURPOSES 109
SOUTH AFRICAN EXPERIENCE
E. M. Nupen and W. H. J. Hattingh, National Institute for
Water Research of the Council for Scientific and Industrial
Research, Pretoria, South Africa
PLANNING FOR WATER REUSE - SOME SOCIO-ECONOMIC ASPECTS 120
J. Gordon Milliken, Denver Research Institute, and
Lucy Black Greighton, Colorado Women's College
CHARGE TO THE WORKSHOP 129
Albert C. Trakowski, Environmental Protection Agency
vii
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WORKSHOP SESSION SUMMARIES !32
WORKSHOP ON TREATMENT RELIABILITY AND EFFLUENT QUALITY 133
CONTROL FOR POTABLE REUSE
Chairman: Michael A. Bellanca, Virginia State Water
Control Board
Vice-Chairman: John M. Smith, Environmental Protection
Agency, NERC, Cincinnati, Ohio
WORKSHOP ON RESEARCH NEEDS RELATED TO TREATMENT FOR 143
POTABLE REUSE
Chairman: Franklin D. Dryden, County Sanitation Districts
of Los Angeles County
Vice-Chairman: Carl A. Brunner, Environmental Protection
Agency, NERC, Cincinnati, Ohio
WORKSHOP ON HEALTH EFFECTS OF POTABLE REUSE ASSOCIATED 153
WITH INORGANIC POLLUTANTS
Chairman: John R. Goldsmith, NIH Cancer Institute
Vice-Chairman: Gunther Craun, Environmental Protection Agency,
WSRL , Cincinnati, Ohio
WORKSHOP ON HEALTH EFFECTS OF POTABLE REUSE ASSOCIATED WITH 162
VIRUSES AND OTHER BIOLOGICAL POLLUTANTS
Chairman: Edwin Lennette, California Department of Health
Vice-Chairman: Gerald Berg, Environmental Protection Agency,
NERC, Cincinnati, Ohio
WORKSHOP ON HEALTH EFFECTS OF POTABLE REUSE ASSOCIATED WITH 171
ORGANIC POLLUTANTS
Chairman: Hans Falk, National Institute of Environmental
Health Science
Vice-Chairman: Robert G. Tardiff, Environmental Protection
Agency, NERC , Cincinnati, Ohio
WORKSHOP ON SOCIO-ECONOMIC ASPECTS OF POTABLE REUSE 178
Chairman: Edward G. Altouney, National Oceanic Atmospheric
Adminis tration
Vice-Chairman: Richard K. Schaefer, Washington Environmental
Research Center , Environmental Protection Agency
PARTICIPANTS 188
viii
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WORKSHOP SUMMARY
The reuse of wastewater offers many
potential benefits in terms of both
water pollution control and augmentation
of existing natural water resources.
This reuse may take a number of forms
depending upon the local conditions and
the quality of the reuse source. Included
among these potential uses are irrigation,
recreation, industrial applications, and
groundwater recharge. In order to maxi-
mize the benefits derived from wastewater
reuse it would be desirable to have the
flexibility to use this water for all
purposes, including direct potable reuse.
In order to accomplish this direct
reuse of water in the most effective
manner, it is necessary to first clearly
define the research and development that
is needed, and then to establish priori-
ties for implementation of this program.
Toward this end, ninety-two participants
attended the "Municipal Wastewater Reuse
Research Needs Workshop". To insure a
broad coverage of all viewpoints, the
participants represented government
regulatory and research agencies, uni-
versities, operating engineers and mana-
gers of large treatment systems, con-
sulting engineering firms, and equipment
manufacturers. The first day of the
workshop was devoted to the presentation
and discussion of current research and
demonstration activities related to treat-
ment technology and health effects
associated with current and proposed water
reuse applications. From these presenta-
tions it was apparent that there is a
limited, but expanding, amount of water
reuse being practiced at the present
time for non-potable purposes. However,
there is increasing interest developing
to accomplish this reuse on a much
broader scale. Likewise, at the present
time there are only a limited number of
municipalities incorporating potable
reuse into their resource planning.
These municipalities must have assurance
of the potability of reuse water prior
to implementing their reuse plans. The
time frame indicated for providing the
technology development and health effects
evaluation necessary to provide this
assurance was indicated to be in the
range of 10-15 years, assuming that a
comprehensive research and demonstration
effort is initiated in the very near
future.
The second and third days of the
meeting were devoted to workshop discus-
sions directed at the specific research
needs in each of the following subject
areas: 1) treatment reliability and
effluent quality control for potable
reuse, 2) wastewater treatment for
potable reuse, 3) health effects of
potable reuse associated with inorganic
pollutants, A) health effects of potable
reuse associated with viruses and other
biological pollutants, 5) health effects
of potable reuse associated with organic
pollutants, and 6) socio-economic aspects
of potable reuse. A number of points
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and research needs were discussed during
these workshop sessions which were common
to several of the workshop groups. These
common points of discussion included:
1. It was the general consensus of
the participants in the workshop
that the research needs identi-
fied for direct potable reuse
should be applied equally to the
indirect reuse of wastewater,
which has been practiced for
some time. This recommendation
applies to the effluent quality
control and reliability studies
which were identified as well as
to the toxicological and epide-
miological study suggestions.
2. Research is needed to identify
the contaminants which are cur-
rently present in domestic water
supplies and to evaluate the
current water treatment processes
to determine their effectiveness
in controlling these contaminants.
This type of characterization
will serve as the basis for
assessing the effect of various
levels of indirect refuse, as well
as providing some insight into
unit process selection for water
renovation. Similar evaluation
of candidate water renovation
processes should be performed to
assess the effectiveness of these
processes and to characterize
the product water for comparison
with existing drinking water
supplies.
3. Development of rapid, sensitive,
and accurate testing procedures
is required for the inorganic,
organic, and biological consti-
tuents in wastewater. In line
with this, indicator parameters
must be identified in each of
these areas which can be used for
continuous, on-line monitoring
of product quality.
4. Toxicological studies are needed
involving the application of in
vitro methods to screen classes
of wastewater contaminants and
their concentrates. This screen-
ing should involve several in
vitro systems including bac-
terial and cell culture systems.
Animal toxicity testing should
be used to validate such tech-
niques where appropriate.
5. Consideration should be given
to a collaborative effort with
the WHO International Reference
Center on Community Water Sup-
plies involving retrospective
and prospective epidemiclogic
surveys of population groups
exposed to indirect wastewater
reuse. The aim would be to
determine whether there are any
detrimental health effects
resulting from such long-term
exposure.
6. The workshop recognized the
strong need for improvement in
the exchange of information
relative to reuse, both within
the United States and throughout
the world. This was identified
as being particularly important
„ as it relates to new developments
in analytical methodology,
treatment technology, and health
effects research. Channels of
communication should be estab-
lished for rapid dissemination
of this information.
In addition to the common areas of
research need which were indicated, each
workshop group identified research and
development needs which were specific to
the assigned workshop. Highlights from
the research needs cited by each of the
six groups are as follow.
Several research areas were in-
dicated by the Treatment Reliability and
Effluent Quality Control group as being
necessary for defining treatment design
goals. These involved establishing water
quality standards for potable reuse,
requirements for fail/safe reliability,
and allowable limits of product quality
variability. With the establishment of
these goals and limits the group outlined
a set of research needs aimed at deter-
mining the equipment and management
requirements for providing the required
renovation system reliability.
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The Wastewater Treatment group
identified a large-scale demonstration
effort as being among the most important
treatment needs. The purpose of this
effort would be to characterize the
long-term effectiveness and reliability
of various alternative treatment systems
for producing a potable quality product.
In evaluating these systems, the effi-
ciency of removal for undesirable waste-
water constituents would be a necessary
criteria, as would the energy requirements,
system costs, overall reliability, and
residue disposal considerations. Addi-
tional work was indicated in the develop-
ment of cost effective processes for
disinfection, trace organic removal,
nitrogen removal, and demineralization.
A balanced use of epidemiological
and toxicological research was indicated
as being extremely important in ascer-
taining the Health Effects of_ Potable
Reuse Associated with Inorganic Pollutants.
The epidemiological program which was
recommended included an assessment of the
relationship between current water quality
and the incidence and prevalence of
chronic diseases, as well as a determia-
tion of the body burdens of inorganic
substances. The strategy called for in
the toxicological studies involved in
vitro screening of concentrated toxicants,
animal toxicity testing, and population
dose estimation.
The workshop group dealing with
Health Effects of Potable Reuse Associated
with Viruses and Other Biological Pollu-
tants highlighted the development and
evaluation of rapid and relatively simple
methods for detection of viruses having
major public health significance as being
among the areas warranting extensive
research. This was coupled to a high
priority for determining the degree and
mechanisms of removal and inactivation of
viruses in reclaimed waters.
The workshop group on Health Effects
of Potable Reuse Associated with Organic
Pollutants recommended that the EPA
develop a viable and visible program to
assess the potability of reused water.
The program should have a program manager
charged with preparing a critical path
analysis, with time and monetary require-
ments, for evaluating the health effects
of potable reuse. In addition, as part
of a toxicity testing program the group
identified the need for an assessment
of the interaction of pollutants to
determine the importance of synergistic
effects on the toxicity of organic com-
pounds which might occur in renovated
wastewater.
Among the recommendations developed
by the working group on Socio-Economic
Aspects of Potable Reuse was a need to
identify the extent to which the U.S.
population is presently being supplied
former wastewater as a part of the raw
water supply. An extension of this
need involved the suggestion that a
public education program be undertaken
to indicate the true picture concerning
the current practice of indirect water
recycling. It was also recommended that
an in-depth investigation of potential
reuse cost-effectiveness be performed
at several specific U.S. locations of
varying characteristics.
In conclusion, the Workshop has
made it apparent that there are many
specific research needs related to treat-
ment technology and reliability, health
effects, and socio-economic considera-
tions for potable water reuse. The
importance of proceeding with the accom-
plishment of this research is related
not only to the recognized need for
future direct reuse, but also because
of the insight these investigations will
provide concerning our current supply
sources, many of which are currently
influenced by upstream discharges of
municipal and industrial wastewaters.
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WORKSHOP OBJECTIVES
Donald P. Dubois, Deputy Regional Administrator
Region VIII, Environmental Protection Agency
In looking over the agenda for this
workshop, I have been impressed with the
scope and organization of the program,
and with the impressive credentials of
the international group of participants
and speakers that have been assembled. I
am confident that the nature of this pro-
gram and the quality of the participants
will allow us to achieve our objective,
which is to define and establish the
priorities for research needed to develop
confidence in the reuse of wastewater for
potable purposes.
I think that is a most worthy objec-
tive for this conference. I suppose we
could ask why it is important that we
achieve this objective. I suspect that
many of you who work in this field on a
daily basis know better than I, but from
my own perspective^, I think the one reason
it is important to achieve this objective
is because we already are reusing water.
For the most part this reuse is not inten-
tional or direct, but relates to the wastes
discharged through our major river systems,
and the subsequent downstream use of that
water for drinking and potable purposes.
Over a long period, the Public Health
Service, now EPA, has developed a very
strong commitment to define what is in
water that is being used in the lower por-
tions of river systems and whether or not
these constituents are harmful to health
and welfare. For those that are harmful
the agency has sought to develop means to
remove these constituents or render them
less harmful. I think the classic example
of the chlorinated organics in the New
Orleans water supply, which came to the
fore here in the last few months, illus-
trates what I am talking about in that con-
text.
Looking again from my perspective here
in the Rocky Mountain-Prairie Region, I
think it is critically important that we
begin to directly reuse water wherever
possible. Particularly in this part
of the country, we are running short of
unused or pristine water supplies. There
are many competing uses for those water
supplies in terms of municipal purposes,
industrial, agricultural, recreational,
and so forth. The environmental impact
of developing some of these pristine
sources can be, and often is, undesirable.
This is evidenced by disruption of stream
flows, alteration of the ecology of the
stream system and fisheries, and by the
concentrating effect on salinity and
other constituents that can result from
depletions of stream flows in the head-
water areas. In addition, the cost of
developing these upstream mountain water
supplies is becoming prohibitive in many
cases.
All of these reasons combine to say
that we must expand our emphasis on
developing means of increasing water re-
use. However, I would introduce a note
of caution at this point. It is clear
that we must know what we are doing be-
fore we rush into a direct reuse program
for potable purposes. I think we must
balance the drive to define reuse tech-
niques with a program to develop answers
to the problems associated with reuse so
that we can be confident that the bene-
fits which we perceive from reuse will
not be offset by possible harmful health
effects. I think that is why you are all
here; to chart a course for a research
and development program that will identify
the benefits, and most importantly, will
define and reduce the risks of water re-
use.
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Congress has recognized the
need for this kind of research and develop-
ment in the Federal Water Pollution Control
Act of 1972, and the Safe Drinking Water
Act of 1974, both of which give EPA strong
authority for research into practically
all phases of waste treatment, water treat-
ment, and reuse. I think your task really
boils down to helping EPA define our re-
search priorities so that we can build on
the research work that has already been
underway for many years and direct it more
into the area of potable water reuse, in
order to better define the risks and what
we can do about them. I hope also that
this workshop will identify what the other
institutions—the universities, the con-
sulting engineers, the municipalities—
can do as their part of the responsibility.
It certainly is not all EPA's responsibtl-
ity.
I do hope you have a successful con-
ference. I am confident that you will.
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OVERVIEW OF WASTEWATER REUSE AND EPA RESEARCH STRATEGY
F. M. Middleton
Deputy Director
National Environmental Research Center
Environmental Protection Agency
Cincinnati, Ohio 45268
ABSTRACT
Water reuse is a common fact of life. Water shortages and the recent recognition in
the United States of the need to conserve water has focused attention upon the value of
more intentional reuse. Planners recognize the need for a hierachy of water use in the
community. All water need not be of the same quality. And the wastewater of a community
should be considered a resource.
Wastewater reuse is being specifically recognized by recent legislation. Public Law
92-500, The "Federal Water Pollution Control Act Amendments of 1972", calls for research
and facilities construction to permit reuse. Public Law 93-253, The "Safe Drinking Water
Act", passed in December 1974 allows for grants to investigate and demonstrate health impli-
cations involved in reclamation, recycling and reuse of wastewaters to prepare a safe and
acceptable drinking water. The American Water Works Association and the Water Pollution
Control Federation have issued a joint statement in support of appropriate reuse.
Municipalities on an annual basis use about 10 trillion gallons of water and waste-
water return amounts to 8 trillion gallons. Present wastewater usage for specific purposes
such as irrigation and cooling amount to only 134 billion gallons or less than 2% of the
available flow. Much of the waste flow can be put to productive use.
A great deal of research in EPA is directed toward some facet of wastewater reuse. A
major effort is now needed to embark upon a long-term integrated program to permit waste-
water reuse for any purpose including to supply drinking water. Some states and major
municipalities are already working on a variety of reuse projects. Our combined programs
should lead us to a sound base of science and technology that will ensure safety and gain
the public confidence for full-scale water reuse. The technology for preparing water of
any quality is well advanced. Needed is better knowledge on the level of residues that
remain and their possible health effects. Social and economic factors will need additional
research.
INTRODUCTION and conservation and reclamation of resources
must become the rule.
Abundant supplies of clean surface and
underground waters in the United States have Water has always been used and reused by
been taken for granted until recent years. man. The natural water cycle, evaporation,
Severe contamination of many surface supplies and precipitation is one of reuse. The return
has occurred. Increasing instances of ground- of wastewaters to the streams and lakes of
water contamination are being found. Thus, the country is a fact of life. The unplanned
our relatively fixed volume of water may reuse of wastewaters is not new. The planned
become less and less usable. Adequate reuse of wastewaters for beneficial purposes
pollution control measures must be taken has been done in some areas for many years,
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but it is here that we need to concentrate
our efforts for far greater use of our
wastewaters. The purpose of this seminar
is to set the research needs and objectives
to move forward in the planned wastewater
reuse area.
The quality and quantity of waste-
waters produced by the community depend
upon such factors as the source of supply,
population density, industrial practices,
and even the attitudes of the local popu-
lation. The quality of the environment can
be improved by reducing pollution at the
source, providing adequate treatment of the
wastewaters, and by recycling and reusing
wastewater. Public support and some change
in social behavior will be required in most
instances.
DEFINITIONS
Since there are many different types
of wastewater reuse and the term "reuse"
has different meanings to different people,
the following definitions will be used for
this Workshop:
Municipal Wastewater - The spent water
of a community, consisting of water-carried
wastes from residences, commercial buildings,
and industrial plants and surface or ground-
waters that enter the sewerage system.
Advanced Waste Treatment - Treatment
systems that go beyond the conventional pri-
mary and secondary processes. Advanced
waste treatment systems may include biologi-
cal processes, the use of chemicals, acti-
vated carbon, filtration, or separation by
membranes.
Indirect Reuse - Indirect reuse of
of wastewater occurs when water already used
one or more times for domestic or industrial
purposes is discharged into fresh surface or
underground waters and is used again in its
diluted form.
Direct Reuse - The planned and deli-
berate use of treated wastewater for some
beneficial purpose such as irrigation, re-
creation, industry, prevention of salt water
intrusion by recharging of underground
aquifers, and potable reuse.
Potable reuse can be further divided
into two categories as follows:
Indirect Potable Reuse - The planned
addition of treated wastewater to a drinking
water reservoir, underground aquifer, or
other body of water designed for potable
use that provides a significant dilution
factor.
Direct Potable Reuse - The planned
addition of treated wastewater to the head-
works of a potable water treatment plant or
directly into a potable water distribution
system.
OFFICIAL SUPPORT FOR WASTEWATER REUSE
The role of the U.S. Environmental
Protection Agency (USEPA) and its predecessor
organizations in wastewater reuse has been
stated in various acts. Public Law 87-88
passed in 1961 amending the Federal ffater
Pollution Control Act directed the Secretary
(at that time of Health, Education, and
Welfare) "to develop and demonstrate practi-
cable means of treating municipal sewage
and other water-borne wastes to remove the
maximum possible amounts of physical, chemi-
cal, and biological pollutants in order to
restore and maintain the maximum amount of
the Nation's water at a quality suitable for
repeated reuse."
This Act gave impetus to the Advanced
Waste Treatment Research Program, which be-
gan in 1960. The objective of this national
program is to conduct research that will
develop new and improve existing wastewater
treatment processes and ultimate disposal
technology, thus permitting maximum removal
of contaminants and repeated reuse of the
Nation's waters.
Public Law 92-500, the "Federal Water
Pollution Control Act Amendments of 1972",
recognizes the potentially large benefit to
be realized if wastewaters can be renovated
for reuse applications. Sections 201 (b),
201 (d), and 201 (g) (2) (B) clearly require
1. that EPA provide for the application of
best practicable waste treatment technology,
including reclaiming and recycling of water;
2. that construction of revenue producing
facilities providing for reclaiming and re-
cycling be encouraged; and 3. that works
proposed for grant assistance, to the extent
practicable, allow for the application of
technology at a later date which will provide
for reclaiming and recycling of water.
Section 105 (a) (2) authorizes EPA to make
grants for demonstrating advanced waste
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treatment and water purification methods,
and Section 105 (d) (2) requires that the
Administrator conduct on a priority basis
an accelerated effort to develop, refine,
and achieve practical application of ad-
vanced waste treatment methods for reclaim-
ing and recycling water and confining
pollutants.
The Safe Drinking Water Act of 1974
(Section 1444) also contains mandates of
importance with regard to renovation and
recycling of wastewaters. Section 1444
authorizes a development and demonstration
program to: demonstrate new or improved
technology for providing safe water supply
to the public; investigate and demonstrate
health implications involved in the recla-
mation, recycling and reuse of wastewaters
for the preparation of safe and acceptable
drinking water.
There exists, therefore, a strong and
clear legislative mandate for research
development and demonstration of reliable,
cost-effective technology for reclaiming
and recycling wastewaters for beneficial
uses. A major beneficial use is the supple-
mentation of domestic water supplies.
The Water Pollution Control Federation
(WPCF) (1) and the American Water Works
Association (AWWA) issued a joint resolution
that urged the Federal Government to support
a massive research effort to develop needed
technology. These organizations underscored
the "lack of adequate scientific information
about possible acute and long-term effects
on man's health from such reuse", and also
noted that "the essential fail-safe tech-
nology to permit such direct reuse has not
yet been demonstrated." The resolution
recognizes the need for an "immediate and
sustained multi-disciplinary, national
effort to provide the scientific knowledge
and technology relative to the reuse of
water for drinking purposes in order to
assure full protection of the public health."
The USEPA in a policy statement on
water reuse dated July 7, 1972, supports
and encourages the development and practice
of successive wastewater reuse. EPA does
not currently support the direct inter-
connection of wastewater reclamation plants
with potable water systems.
SPECIFIC CONSIDERATIONS GOVERNING REUSE
The reuse of treated effluents is most
applicable where large volumes of water are
used and the wastes are not highly contami-
nated. The location of the treatment plant
and the possible transport of the renovated
water are important considerations. A waste-
water renovation plant need not always be
located at the same place as the municipal
wastewater disposal plant, nor should the
renovation process be dependent upon treat-
ing the total flow. Treatment processes
work most efficiently and economically when
dealing with a steady flow of wastewater
rather than with the irregular flow normally
experienced from urban sources. This condi-
tion can be obtained by withdrawing only a
part of the urban wastewater; this is depict-
ed in Figure 1, which shows how water reno-
vation and reuse can be planned to best
advantage in the community.
VOLUME OF WASTEWATERS
AVAILABLE IN MUNICIPALITIES
Municipalities on an annual basis use
about 10 trillion gallons of water, and
wastewater return amounts to 8 trillion
gallons. Present wastewater usage for
specific purposes is shown in Table 1.
As can be seen from the Table, only
136 billion gallons, or less than 2% of the
available flow, is used on a planned basis.
Much of the waste flow can be put to produc-
tive use. Such uses can go a long way in
conserving scarce clean water sources.
STANDARDS FOR WASTEWATER REUSE
To ensure the safety of water supplies,
standards have to be applied. Standards for
drinking water have been available for many
years. Although national standards may be
set for drinking water, the qualities of
river-water, industrial effluents, and re-
used wastewater are the responsibility of
the local controlling authority. Even so,
the standards set must take into account
the possible transport of pollutants across
state borders or the effects of discharges
on downstream water users. Standard setting
is a most difficult and critical job, with
important economic implications. Standards
must be given the force of law, and an
authority must be created to ensure that
they are observed.
-------
DISCHARGE OF
HOUSEHOLD SEWAGE
DISCHARGES
OF INDUSTRIAL
WASTES UNSUITABLE
FOR RECLAMATION
1 1
TRUNK E
SEWER
' .
VEN FLOW
TO PLANT
WASTEWATER
j
•••MI
1
SLUDGES
RETURNED
TO SEWER
RENOVATION PLANT
-CLEAN WATER FOR REUSE
TO MUNICIPAL
DISPOSAL PLANT
The diversion of wastewater from the trunk sewer to the wastewater renovation plant
should be chosen at a point where it is known that the trunk sewer contains only household
sewage.
FIGURE 1. Simplified Wastewater Reuse Scheme*
'From World Health Organization Technical Report No. 517 (1973)
TABLE 1. Water Reuse in the United States
Type Volume in 1971
Irrigation and agriculture 77 bg
Industrial 54
Recreational 3
Non-potable domestic *1
*Groundwater augmentation *1
No. of Plants
338
14
5
1
8
*Estimated from information in EPA publication EPA-660/2-73-006b
"Wastewater Treatment and Reuse by Land Application" - Vol. I & II
-------
Standards governing the quality of
water in rivers and lakes are becoming
common. Some countries have, and others
are formulating, standards applicable
directly to effluents, though few countries
yet have standards for the planned reuse of
treated wastewater. As wastewater reuse
grows, it is important that standards be
set for specific reuse purposes.
As wastewater - treated or untreated -
has been reused in agriculture for a fairly
long time, some countries have developed
standards for this purpose. A summary of
some representative standards for the use
of renovated water in agriculture is given
in Table 2.
TABLE 2. EXISTING STANDARDS GOVERNING THE USE OF RENOVATED
WATER IN AGRICULTURE*
California
Israel
South Africa
Federal Republic
of Germany
Orchards and
vineyards
Primary effluent;
no spray irrigation ;
no use of dropped
fruit
Secondary
effluent.
Tertiary effluent,
heavily chlorinated
where possible. No
spray irrigation.
No spray irrigation
in the vicinity.
Fodder,
fibre crops,
and seed
crops
Primary effluent;
surface or spray
irrigation.
Secondary effluent,
but irrigation of
seed crops for
producing edible
vegetables not
permitted.
Tertiary effluent.
Pretreatment with
screening and
settling tanks.
For spray Irrigation,
biological treatment
and chlorination.
Crops for
human con-
sumption that
will be pro-
cessed to kill
pathogens
For surface irriga-
tion, primary
effluent.
For spray irrigation,
disinfected sec-
ondary effluent (no
more than 23 coli-
form organisms per
100 ml).
Vegetables for hu- Tertiary effluent.
man consumption
not to be irrigated
with renovated
wastewater unless
it has been properly
disinfected (< 1000
coliform organisms
per 100 ml in 80% of
samples).
Irrigation up to
4 weeks before
harvesting only.
Crops for
human con-
sumption in
a raw state
For surface irriga-
tion, no more than
2.2 coliform organ-
isms per 100 ml.
For spray irrigation,
disinfected, filtered
wastewater with
turbidity of 10 units
permitted, provid-
ing it has been
treated by coagula-
tion.
Not to be irrigated
with renovated
wastewater unless
they consist of
fruits that are peel-
ed before eating.
Potatoes and
cereals — irrigation
through flowering
stage only.
ff J ™
*From World Health Organization Technical Report No. 517 (1973)
10
-------
DOMESTIC REUSE
In any reuse application there are
a number of points to consider. One very
important question is whether the reuse
will result in multiple recycle. Multiple
recycle produces a buildup of refractory
materials, especially inorganic ions, and
may require the use of demineralization or
other specialized processes. In-plant reuse
of industrial water, where actual consump-
tion is small, may lead to a high degree
of recycle. On the other hand reuses of
municipal wastewater, except for domestic
reuse, probably would not lead to multiple
recycle. Even in the case of domestic
reuse there is not likely to be total
recycle. The reason is that less water
is ordinarily found arriving at the waste-
water treatment plant than is supplied to
the municipal water system. Such losses
do occur and are quite large in warm, dry
areas where domestic reuse is likely to
be most widely practiced. In the United
States, it is estimated (2) that these
losses range from less than 20% in humid
areas to about 60% in arid areas. Park-
hurst et al., (3) point out, based on
experience in the Los Angeles area, that
less than 50% of a water supply would be
available for reuse. The disadvantage of
these large losses is the need for a sub-
stantial additonal fresh water source. The
advantage is that the steady state mineral
concentration is reduced. As a result, the
degree of demineralization may be reduced
substantially below that needed if there
were no losses. Also, there is the flexi-
bility of demineralizing either the renovat-
ed wastewater or the supplementary water
source; there may be advantages to deminer-
alizing the supplementary source.
Another consideration in reuse is the
character of the wastewater entering the
treatment plant, especially with respect
to industrial pollutants. Care must be
used to exclude materials that would be
detrimental to the reuse application. This
is especially true for domestic reuse, but
also applies to less sophisticated reuse
applications. These materials may not be
those usually considered toxic. Ordinary
salt brines would be undesirable, for
example, if demineralization were being
carried out on the renovated wastewater.
In Los Angeles County, a survey of the
sewer systems has been made to determine
how much of the available wastewater has
potential for reuse. Waters having heavy
metal contamination or high total dissolved
solids were considered unacceptable. A
similar survey will be necessary for other
municipalities planning extensive reuse.
Another point that must be considered
is distribution of the renovated water. A
multiplicity of piping systems, each one
containing a different quality renovated
water, will not usually be practical. There
may be a number of large consumers in the
vicinity of the treatment plant. This
would make distribution simple and inexpen-
sive. If the consumers are widely distri-
buted, however, one piping system in addi-
tion to the existing municipal water system
is almost certain to be the most that will
be economically realistic. The result is
that the renovated wastewater must be of
a quality to satisfy most of the customers
without additional treatment. Treatment
such as those necessary for boiler water
feed would be excluded, since present
practice in water supply has shown that
those treatments are more appropriately
carried out by the user.
INDIRECT REUSE OF WASTEWATER
A study of a number of rivers, carried
out in 1961 by Koenig (4), showed that, at
periods of low flow, 3.5% to 18.5% of the
water had passed through domestic systems.
If the volume of industrial effluents is
taken into account, it would be expected
that 20% to 40% of the river water at low
flow in some areas may be reused water.
The lower Rhine River serving as a drinking
water source for 6 million people is 40% to
nearly 100% sewage effluent depending upon
flows. The river Thames, serving as source
for two-thirds of the water for London
flowing at an average rate is about 14%
sewage effluent.
These levels of contamination indicate
the increasing need to consider the optimum
distribution of purification among the waste-
water treatment plant, the river itself
(self purification), and the plant that
produces potable water. Adequate answers
require analysis of the costs and benefits
involved. More and more, around the world,
"river basin authorities" are taking control
over the treatment and discharge of waste-
waters, and over the abstraction and treat-
ment of potable waters.
11
-------
DIRECT REUSE OF WASTEWATERS
RESEARCH STRATEGY
Treated wastewater may be deliber-
ately used in a planned way for a variety
of purposes, some of which are shown in
Figure 2.
A comprehensive survey of demonstrat-
ed reuse technology has been made by SCS
Engineers (5). A variety of direct and
other reuse applications of effluents has
been published by the World Health Organi-
zation (6).
A substantial base of science and
technology already exists for many waste-
water reuse applications. We need now to
plan our research to achieve the highest
quality water and assure its safety for any
use. We expect this Workshop to provide a
charted path that can guide workers for
several years. Some of the areas to be
considered follow:
MUNICIPAL
WASTEWATER
INDUSTRIAL
WASTEWATER
MUNICIPAL
NONPOTABLE
J
1
RINKING
1
1
RECREATION
,
1
WIMMING
FISH
CULTURE
1
| BOATING ]
FISHING]
L
f
1
AGRICULTURE INDUSTRY
I
1
INTRA-PLANT
(
STOCK
WATERING
ORCHARDS
AND
VINEYARDS
FODDER, FIBRE
CROPS AND
SEED CROPS
CROPS CONSUMED
AFTER PROCESSING
CROPS
CONSUMED
RAW
FIGURE 2. Intentional Reuse of Wastewater*
•From World Health Organization Technical Report No. 517 (1973)
12
-------
HEALTH EFFECTS OF CONTAMINANTS
TREATMENT TECHNOLOGY
Full-scale reuse will be inhibited most
by questions concerning health effects. We
are constantly reminded that very low, but
significant, concentrations of toxic chemi-
cals and carcinogens appear in our environ-
ment. Often it is only after many years of
exposure that the deleterious effects are
associated with the cause. How can we
improve our ability to screen and predict
what is harmful? What concentrations of
materials are tolerable in water? Do the
harmful materials accumulate in the food
chain? In addition to safety for potable
purpose, we need information on health
effects from body contact, stock watering,
irrigation, and fish propagation. Follow-
ing laboratory studies of pathogenic,
toxic, carcinogenic, and teratogenic
effects, epidemiological studies will be
a necessity.
QUALITY CONTROL OF RENOVATED WATER
Quality control is essential for any
water derived from polluted sources, and
the more recent the derivation, the more
important the quality control. In planning
water reuse projects, a positive laboratory
testing and control program must receive
high priority. The types of examinations
needed are outlined below:
Biological examination should include
microscopic tests for protozoan cysts and
eggs of parasites. The usual examinations
should be made for bacteria. Virus testing,
which is both time consuming and expensive,
will need to be put on a more routine basis
if potable reuse becomes common. Good
progress has been made in recent years in
methodology for sampling and testing viruses.
Bioassays have a large role in assessing
possible toxicants in effluents.
Chemical testing can be tailored to
the quality requirements and the reuse
application. Almost any reuse would require
measurement of pH, suspended solids, chemi-
cal oxygen demand, total organic carbon,
total dissolved solids, alkalinity, turbid-
ity, ammonia, nitrates, phosphorus, and
any suspected toxic chemicals such as heavy
metals. Direct measurement of pesticides
and trace organic residues is both important
and possible with modern instruments.
In the past 15 years, significant
advances have been made in wastewater treat-
ment technology. The organic content of
wastewater can be reduced to very low con-
centrations through the application of
chemicals, use of filters, and activated
carbon. Membrane treatment offers still
another separation technique. Phosphorus
and nitrogen removal technology is good.
Bacterial and virus removal capabilities
of treatment processes are high. However,
some portion of the contamination remains
after the best treatment. To finally
remove all contaminants may require ex-
cessive processing and accompanying costs.
Before programming large amounts of money
and effort, the technologists need to know
what residue limits are acceptable. Some
specific goals in treatment technology are:
1. Continue the development and refine-
ment of treatment technology to prepare
water of any quality.
2. Collect performance, reliability,
and cost data for alternative treat-
ment systems.
SOCIO-ECONOMIC RESEARCH
It is the public who eventually pays
the costs of water, and they are rightfully
included in the decision making process.
The full facts about reuse need to be made
known and the reliability of technology
fully explored and explained. Public
attitudes must be sought on reusing water
for potable purposes. Accurate assessment
of the alternatives and costs of water will
determine where and when reuse occurs.
RESPONSIBILITIES TO PROMOTE REUSE
Water reuse, if we are to achieve the
maximum benefits, has to be planned on a
broad basis. How might the responsibilities
for optimum reuse be distributed? The
Federal role has been outlined earlier in
this paper. Let us consider the role of
the local agency and industry.
13
-------
Local Agencies Role in Water Reuse
1. Promote to the extent possible,
consistent with water quality con-
siderations, the renovation and reuse
of wastewaters.
2. The water reuse potential on an
area-wide basis should be determined.
Specific studies on reuse in sub-
areas would follow. Examples of
objectives include the following:
a. Determine a ranked order of water
uses in the local area in accord-
ance with the acceptability of
different levels of water quality.
b. Demonstrate how water recla-
mation can supplement available
water supply.
c. Demonstrate how wastewater
reclamation can relieve down-
stream collection and treatment
systems.
d. Develop legislative, economic
and planning procedures to
implement water reuse.
e. Examine all available technology
for reuse, assess public acceptance,
aesthetics, and cost-benefit
ratios.
Industrial Role in Water Reuse
1. Examine all plant practices to
obtain optimum water use and recycle
with a minimum of waste effluents.
Try to become a minimum discharge
industry.
2. Consider the use of available
waters of secondary quality (sewage
plant effluents, brackish waters,
sea water, etc.) for suitable
plant purposes.
3. Examine chemicals and processes
contributing to pollution and deter-
mine if changes in either will help
abate pollution.
4. Consider product recovery from
waste materials.
5. Be aware of the new developments
in processes to control pollution.
6. Make all plant personnel water and
pollution conscious.
TIME TABLE
The United States is in the fortunate
position of not needing to immediately turn
to wastewaters as a direct source for pre-
paring potable waters. Other countries
such as South Africa and Israel have more
urgent needs, and we shall learn from them.
We all know of the long time needed to bring
research results into practical full-scale
use. Our time to develop and prove full-
scale reuse is short. Our needs for reuse
will be much greater in 10 years, and in 20
years, it will be a necessity in many parts
of the United States and around the world.
We hope this Workshop will be the starting
point toward an integrated national effort
that will bring about orderly, safe develop-
ment of wastewater reuse.
REFERENCES
1. Water Pollution Control Federation Adopts
Water Reuse Policy, Journal of Water
Pollution Control Federation. Vol. 45,
p. 2404 (1973).
2. "The Nation's Water Resources", The First
National Assessment of the Water Resour-
ces Council, Washington, D.C. p. 4-1-2
(1968).
3. Parkhurst, J. D., Carry, C. W., Masse,
A. N., and English, J. N., "Practical
Applications for Reuse of Wastewater",
Chemical Engineering Progress Symposium
Series, Vol. 64, No. 90, p. 225 (1968).
4. Koenig, L., Studies Relating to Market
Projects for Advanced Waste Treatment.
U.S. Dept. of the Interior, Federal
Water Pollution Control Administration,
Publication No. WP-20-AWTR-17 (1966).
5. SCS Engineers - Schmidt, Curtis J. and
Clements, Ernest V. Ill, Demonstrated
Technology and Research Needs for Reuse
of Municipal Wastewater, Contract No.
68-03-0148 prepared for the U.S. Environ-
mental Protection Agency, Washington,
D.C. 20460 (In press).
6. Reuse of Effluents: Methods of Waste-
water Treatment and Health Safeguards.
World Health Organization, Technical
Report Series, No. 517 (1973) Geneva,
Switzerland.
14
-------
CURRENT MUNICIPAL WASTEWATER REUSE PRACTICES
C. J. SCHMIDT
President, SCS Engineers
4014 Long Beach Boulevard
Long Beach, California 90807
ABSTRACT
Reuse of municipal wastewater for irrigation, industrial, recreational,
groundwater recharge, and non-potable domestic purposes is currently being
practiced at over 365 locations in the United States. Much can be learned
from the practices and experiences at these existing locations and new reuse
projects should thoroughly investigate existing projects practicing similar
reuse applications. Overall, the reuse potential in this country has hardly
been touched. By contrast Israel is reported to reuse over 80 percent of
its domestic sewage effluent. The greatest reuse potential is expanded use
for irrigation (e.g., out of over 6,000 golf courses in the U.S., only 40
are irrigated with municipal effluent), and greatly expanded use by industry
especially for cooling (there are only 11 examples of industrial reuse in
the whole nation). In the semi-arid states recreational reuse and ground-
water recharge has excellent economic potential. In our opinion, the non-
potable uses for municipal effluent are a far more productive area for our
nation's reuse efforts than is potable reuse. We must guard against over-
emphasizing the glamorous controversies of potable reuse at the expense of
ignoring proven reuse possibilities existing all around us.
INTRODUCTION
From 1972 to 1974 SCS Engineers
conducted several studies for EPA of
current municipal wastewater reuse
practices. The primary purpose of
these studies was to make a state-
of-the-art survey which would bring
together information about existing
reuse operations in a concise form.
This information can be used by de-
sign engineers in the design of new
reuse systems and by governmental
decision makers in planning whether
such systems are appropriate to their
situations. It is also a useful
tool for responsible management and
technical personnel in locating
existing reuse operations which can
provide valuable background exper-
ience. A second purpose was to spot-
light deficiencies in the available
reuse information and to suggest
future research to overcome these
deficiencies.
SCOPE
The project compiled an updated
listing of municipal wastewater re-
use operations existing in:1972 and
utilized questionnaires and field
visits to obtain information des-
cribing current treatment and reuse
practices.
The study was limited to reuse
of wastewater from municipal plants
with emphasis upon direct reuse of
the water as it leaves the treatment
plant. Projects involving indirect
reuse by downstream withdrawal of
surface waters containing wastewater,
and industrial,reuse of in-plant
water were not included.
15
-------
The types of reuse covered in
this study are:
. Irrigation and other agricul-
tural uses
. Cooling water
. Industrial process water
. Boiler feed water
. Recreational lakes
. Fish propagation
. Non-potable domestic use
. Groundwater recharge
A total of 367 United States and 55
foreign reuse sites were tentatively
identified. Of the 367 U.S. sites,
205 were judged to be very small
irrigation disposal operations. A
detailed 11 page questionnaire was
sent to the 162 other American sites
and 55 foreign sites. The U.S.
respondents totaled an excellent 154
out of the 162 questionnaires sent
out. Foreign response was poor —
totaling only 6 out of 55 question-
naires sent.
EXTENT OF REUSE
As shown in Table 1, by far the
greatest number of plants practice
reuse by irrigation. In terms of
volume, however, irrigation reuse
accounts for only slightly more than,
half the reuse reported with indus-
trial reuse a close second. Table 2
shows the comparative volumes by
types of reuse. One large industrial
reuser, the Bethlehem Steel Corpora-
tion, in Baltimore, Maryland, sig-
nificantly affects the volume com-
parison because it utilizes 170 mgd
(643,450 cu m/day) for once-through
cooling.
Geographically, the reuse opera-
tions are concentrated in the semi-
arid southwestern United States. As
shown in Table 1, Texas with 149
municipal reuse operations and Cali-
fornia with 145 are far ahead of
other states.
Among foreign countries, Israel
is a leader in municipal wastewater
reuse. Roughly 86 percent of the
country's total treated wastewater
volume was reused in 1972 — 62 per-
cent for irrigation and 24 percent
for groundwater recharge.
IRRIGATION REUSE
The survey showed a surprising
variability in the types of crops
being irrigated with municipal
wastewater. Successful irrigation
of 39 different crops was reported,
ranging from turf (grass) for rec-
reation (i.e., golf courses, parks,
etc.) at 40 locations, down to sugar
beets at 3 locations. Other crops
included truck vegetables, tree
fruits, and all types of grains.
Table 3 indicates the level of
municipal treatment given various
categories of crops. Approximately
three-fourths of the plants provide
the equivalent of secondary treat-
ment. Interestingly, virtually all
categories of crops are also irri-
gated by primary treatment effluent
at some locations.
A wide range of effluent qual-
ity is being applied to crops of
various locations (e.g., BOD of 15
to 370 mg/1 for cotton) ,showing that
the effluent quality ranges from
poor primary to excellent secondary.
Of particular interest are the high
average TDS (over 800 mg/1) and Na
(over 300 mg/1) levels of reclaimed
waters used for irrigation. These
average values indicate that rela-
tively poor waters in terms of
dissolved salts are being success-
fully used on a wide variety of
crops. Table 4 shows survey results.
When one compares the water quality
values with recommended quality
ranges for crop irrigation, it can
be seen that "violations" of. the
recommended ranges are commonplace.
Proper irrigation management is the
key. Consideration must be given to
the interrelationships between soil
tvPe/ crop tolerance, drainage,
water application rate, climate, and
other factors.
The prevalent relationship
between the municipal suppliers of
effluent and the users of the ef-
fluent for irrigation is to suit the
crop to the quality of the effluent.
If contaminants are present which
are not readily removed by conven-
16
-------
TABLE 1.
GEOGRAPHICAL DISTRIBUTION OF REPORTED
MUNICIPAL REUSE
Number of municipalities
practicing reuse
State
Texas
California
Arizona
New Mexi co
Colorado
Nevada
Other
Total
Irr.
144
134
28
10
5
4
13
338
Ind.
5
1
2
0
1
2
3
14
Rec.
0
3
0
0
1
0
1
Rech.
0
7
1
0
0
0
1
Dom.
0
0
1
0
0
0
0
Total
149
145
32
10
7
6
18
367
TABLE 2. REPORTED REUSE VOLUMES BY TYPE
OF REUSE
Type of Reuse
Irrigation
Industrial
Groundwater Recharge
Recreational
Domestic (Non-Potable)
1971 Volume
bil gal*
77
53.5
12**
1.5
.01
*1 gal = 3.785 1.
**Expected to double in 1976 with
addition of Orange County, California;
Phoenix, Arizona; Oceanside, California;
and Palo Alto, California, projects.
TABLE 3. MUNICIPAL TREATMENT PROVIDED FOR IRRIGATION
REUSE ON SPECIFIC CROPS
Crop
Grain
Corn
Vegetables
Fruit
Cotton
Fodder
Pasture
Turf and
Landscape
Number of
treatment
plants*
17
11
6
12
26
51
34
47
Treatment level (% of plants)
Primary Secondary Tertiary
23
36
14
18
29
24
20
77
64
86
82
71
73
71
70
0
0
0
0
0
3
9
21
*Certain plants supply water to more than one crop.
17
-------
TABLE 4. QUALITY OF EFFLUENT APPLIED TO CROPS
Crop
Grain
Corn
Vegetables
Fruit
Cotton
Fodder
Pasture
Turf &
Landscape
No. plants
irrigating*
17
11
6
12
26
51
34
47
BOD (mg/1)
SS (mg/1)
TDS (mg/1)
Low High Avg Low High Avg Low High Avg
10
10
6
10
15
1
7
1100
370
1100
160
370
370
370
180
76
193
32
84
54
50
10
10
6
9
12
0
2
173
135
127
135
259
259
118
71
69
31
58
94
66
40
324
8
5
14
324
8
6
80
19
200
*Certain plants supply water to more than one crop
tional treatment, e.g., TDS and
Boron, crops are selected which tol-
erate the contaminant.
Few of the reuse applications
are irrigation of crops for human
consumption. Most of the crops for
human consumption are those that do
not come into direct contact with ef-
fluent such as grapes, citrus, and
other tree crops. Truck crops such
as asparagus, beans, cucumbers,
onions, spinach, and tomatoes are ir-
rigated at least partially with
effluent only at three California
sites — Camarillo, Irvine, and
Livermore; and at two Washington
sites — Walla Walla and Warden.
Table 5 shows the prevalence of
effluent storage prior to irrigation.
Only 18 of the irrigation reuse
operations reported no effluent stor-
age available, and most have storage
of two days or more. Comments re-
ceived from operators, irrigators,
and regulatory agencies emphasized
the importance of substantial storage
facilities for effluent and tailwater
in order to balance irrigation de-
mands, allow for rainy periods when
the fields are saturated, and pre-
vent run-off.
Effluent transport distances to
potential reuse sites is an impor-
tant economic factor. Table 5 also
displays the ranges of irrigation
water transport distances reported
by current agricultural reusers.
The figure illustrates that 20 per-
cent of all irrigation reusers are
directly adjacent to the municipal
treatment site and less than 6 per-
cent are more than 4 miles away.
The data received indicates that the
bulk of the reusers lie two miles or
less from their supplier.
Only 25 municipal producers of
irrigation water report they sell
their renovated product. Most muni-
cipalities look upon the irrigation
operations as primarily a means of
disposal and are not prone to de-
manding payment for effluent which
they would otherwise waste. In some
cases, the irrigation operation
allows the municipality to provide
18
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TABLE 5. STORAGE CAPACITY OF IRRIGATION WATER
SUPPLY FACILITIES AND DISTANCE FROM
TREATMENT PLANT TO IRRIGATION REUSE
LOCATION
Available
storage
time
days
0
0.5-1
1-2
2-10
10-20
20-30
over 30
Number
of
plants
17
2
7
26
7
9
16
Transport dist.
from treatment Number
pit. to irri. of
reuse-miles* plants
0 25
0-0.25 7
.25-.5 22
.5-1 14
1-2 18
2-4 14
over 4 7
*1 mile = 1..61 km.
only primary treatment, whereas if
discharge were made to surface
waters, a high degree of secondary
treatment would be necessary. Muni-
cipal revenues from irrigation are
estimated to equal less than 1 per-
cent of the treatment cost incurred
by the municipalities charging for
their effluent.
Among those municipalities
charging for their effluent, it ap-
pears that charges for effluent are
primarily influenced by factors
other than effluent quality. Among
these factors are fresh water cost
and availability in the area, prior
water rights in the area, and the
municipality's failure to recognize
its effluent as a valuable commodity
rather than something to be dis-
carded.
INDUSTRIAL REUSE
Responses to this survey indi-
cated that reuse of municipal waste-
water effluents by industry amounted
to 53.5 bil gal (202.5 bil 1) in
1971, or 40 percent of the total
United States reuse volume. The
bulk of the industrial reuse volume
is due to one user, the Bethlehem
Steel Plant in Baltimore, Maryland,
which utilizes 44 bil gal (166.5 bil
1) annually for once-through
cooling.
Only 14 industrial plants were
found to be reusing municipal waste-
water in the United States.1 These
14 facilities include 3 city-owned
power plants, so private industry is
represented by only 11 plants in the
entire nation. Obviously, numerous
potential reuse opportunities remain
unrecognized.
Water quality requirements vary
widely between industries, between
different plants in the same indus-
try, and between various processes
within a single plant. The bulk of
industrial water is used for cooling,
boiler feed, washing, transport of
materials, and as an ingredient in
the product itself. As shown in
Table 6, cooling is predominant in
the reuse of municipal wastewater,
accounting for approximately 154 mgd
(582,890 cu m/day) out of.the total
156 mgd (590,460 cu m/day) reported
industry reuse.
Table 7 shows the major indus-
try classifications using municipal
wastewater. Power generation leads
the list with 6 plants followed by
petro-chemical with 5.
19
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TABLE 6. TYPE OF INDUSTRIAL REUSE
IN THE UNITED STATES
Type of Number of
use plants(1)
Boiler
feed
Process
Cooling
3
3
12
Percent
of
totals
17
17
66
Reuse
volume
(mgd)(2)
1
1
154
(l)Some plants use municipal effluent
for more than one use.
(2)One mgd = 3,785 cu m/day
TABLE 7. MAJOR INDUSTRY CLASSIFICA-
TIONS USING MUNICIPAL
WASTEWATER
Industry
Basic Metal
Manufacturers
Power Generation
Petro-Chemi cal
Mining and Ore
Processing
Number
of
plants
1
6
5
Percent
of total
volume
reused
74
20
5
Cooling Water
Eleven of the fourteen indus-
trial reusers report cooling water
as the primary use for the reclaimed
municipal sewage. Cooling water
technology is complex, and the use
of reclaimed sewage presents special
problems of treatment and control to
responsible operating personnel. .
The differences between treated sew-
age effluent and fresh water must be
recognized and planned for, or seri-
ous problems may occur in the heat
exchange and cooling system.
Table 8 shows practice at spe-
cific locations in gearing cooling
water make-up treatment methods .to
the quality of the municipal efflu-
ent being used. The table indicates
that superior quality sewage efflu-
ents, e.g., the city of Burbank,
California, can be used successfully
with only an increase in chlorine,
acid, and corrosion inhibitors
required to put the effluent on al-
most equal status with fresh water.
If, however, the treated sewage ef-
fluent is of average quality or
worse, then lime clarification
treatment is necessary to remove
suspended solids and organics prior
to use.
Boiler Feedwate r Make-Up
Three industrial plants in Texas
report the use of sewage effluent
for makeup to boilers. Each of the
users provides substantial addi-
tional treatment, the extent of
which is dependent upon the type of
boiler for which the makeup water is
intended. Low pressure boilers suc-
cessfully utilize effluents which
have been clarified, softened, and
reduced in phosphates. High-pres-
sure boilers require makeup water
which has been given the additional
treatment steps of dissolved solids
removal or deionization.
Industrial Process Water
Three plants reported using
reclaimed sewage effluents for pro-
cessing purposes. All are in the
mining and steel making industries.
These are:
Bagdad Copper Corporation
Bagdad, Arizona
Phelps Dodge Corporation
Morenci, Arizona
Bethlehem Steel Corporation
Baltimore, Maryland
The two Arizona plants utilize
the sewage effluent in the mining of
copper. Bethlehem Steel Corporation
uses the bulk of its 170 mgd
(643,450 cu m/day) inflow of treated
sewage effluent for cooling pur-
poses, but small amounts are also
used for a variety of processing
within this fully integrated iron
and steel plant,
Transport and Storage
Transport distances are often
an important consideration in the
feasibility of wastewater reclama-
20
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TABLE 8
EFFLUENT QUALITY VERSUS USER TREATMENT
REQUIRED FOR COOLING TOWER MAKE-UP WATER
Effluent quality
mg/1
Selected Users
City of
Burbank, CA
Nevada Power Co.
Las Vegas, NV
BOD SS
2 2
20 20
Southwestern 10
Public Service
Company
Amarillo, TX
City of 30
Denton, TX
El' Paso Products 10
Company
Odessa, TX
TDS
500
1,000-
1,500
15 1,400
30
130
13 1,300
tion. Table 9 shows the distances
of various industrial users from the
municipal suppliers. In all re-
ported cases, the user has been
responsible for financing the efflu-
ent transport facilities.
User treatment
processes
Shock chlorination, pH adjust-
ment, corrosion inhibitor
Shock chlorination, lime
clarification, pH adjustment,
corrosion inhibitor
Lime clarification, ph
adjustment, shock chlorination,
corrosion inhibitor
Shock chlorination, ph adjust-
ment, corrosion inhibitor
(Treatment insufficient for
effluent of this quality)
Lime clarification, pH
adjustment, filtration,
softening.
Storage facilities for the
reclaimed effluent were constructed
by eight of the industrial reusers.
Table 9 illustrates the range of
storage facility sizes.
TABLE 9. STORAGE CAPACITY OF INDUSTRIAL WATER
SUPPLY FACILITIES AND DISTANCE FROM
TREATMENT PLANT TO INDUSTRIAL REUSE
LOCATION
Available
storage
time
days
0
.5-1
1-5
" over 5
Number
of
plants
5
1
5
2
Transport distance
from treatment plants Number
to irrigation reuse - of
miles* plants
0 - .5
.5-1
1-2
2-4
4-6
over 6
1
3
4
3
1
1
*1 mile = 1.61 km
21
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Industrial Reuse Economics
Economics is the prime motivat-
ing force of industry, and the use
of reclaimed wastewater is governed
by the cost of alternate water sup-
ply procurement and treatment. In
locations where public water sup-
plies of good quality and quantity
are available at low cost, treatment
and reuse of renovated water by in-
dustry has not been economically
attractive. Thus, it is not sur-
prising that most industrial users
of treated municipal effluent are in
the semi-arid southwestern states
where water costs are relatively
high and water quality tends to be
poorer in terms of TDS and hardness.
Several of the industrial plants
do not have an adequate alternate
source of water and are strongly de-
pendent upon their sewage effluent
supply. Most of the other plants,
however, have chosen to use re-
claimed water because it is more
economical than use of fresh water.
The cost of reclaimed water may
be divided into two parts. First,
the cost of procuring the reclaimed
water, including payments to the
municipality, construction of efflu-
ent transportation facilities, and
all other costs required to deliver
the effluent to the industrial plant
site. Second, the cost of treating
the reclaimed water to make its
quality suitable for the intended
use.
When comparing reclaimed water
to fresh water, the cost of pro-
curing reclaimed water is virtually
always less; however, the cost of
treatment is usually more. Disre-
garding Colorado Springs, which is a
pilot operation, the range in pur-
chase price of municipal effluent to
industrial users is nothing to
$144/mil gal ($38,100/mil cu m) with
a median of $79/mil gal ($20,800/mil
cu m) .
Additional treatment costs
generally comprise the largest por-
tion of the cost of reclaimed water
to industry. The treatment costs
depend upon the end use quality
required, the quality of the sewage
effluent, the degree of treatment
required, the quantity of water
treated, and other factors. For
cooling water use in recirculating
systems, the reported industry
treatment costs varied from $100/mil
gal ($26,400/mil cu m) to $550/mil
gal ($145,500/mil cu m). As shown
in Table 10, the lower cost is for
treatment of, exceptionally high-
quality effluent produced at Bur-
bank, California, and the higher
cost is for a very sophisticated
reclaimed water treatment system at
Odessa, Texas.
For boiler feed makeup water
use, Cosden Oil and Chemical Com-
pany reported treatment costs of
$742/mil gal ($196,000/mil cu m).
Treatment costs incurred at other
plants treating a portion of the
effluent for boiler feed makeup
water are estimated by SCS Engineers
to be in the range of $500/mil gal
i($132,000/mil cu m) to $l,000/mil
gal ($264,000/mil cu m), as shown
in Table 10.
The revenue received by the
municipalities from industrial re-
users is less than the cost of
treatment to the municipality. How-
ever, in all cases, the municipality
would have had to provide equivalent
treatment prior to discharge in any
case, so any revenues for sales of
effluent are a bonus to the local
municipal taxpayer.
RECREATIONAL LAKE REUSE
There are three major recrea-
tional lake reuse projects in the
United States; i.e., Santee, Tahoe,
and Lancaster, California. Each of
these recreational lake projects
has provided important background
for advances in wastewater treat-
ment.
The Santee County Water Dis-
trict Lakes project is justifiably
famous for its pioneering work.
Since 1961, the Santee Lakes have
been used progressively for recrea-
tional activities involving in-
creased human contact as laboratory
results and epidemiological
22
-------
TABLE 10
INDUSTRIAL USER
COSTS FOR RECLAIMED WASTE
User
Cost to
Procedure
Effluent
($/mil gal)*
User
Treatment
Cost
($/mil gal)*
Total
Effluent
Cost
($/mil gal)*
Bagdad Copper Corp. 0 0
Bagdad, Arizona .(Process)
Phelps Dodge Corp. 0 0
Morenci, Arizona (Process)
City of Burbank 43 100
California (Cooling)
City of Colorado Springs 320
Colorado (Cooling)
Bethlehem Steel Corp. 1.33 (avg) N/A
Baltimore, Maryland
(Cooling^ Process)
Dow Chemical Co. (Cooling) 3.33 (avg) N/A
Midland, Michigan
Nevada Power Co. (Cooling) 25 193
Las Vegas, Nevada
Champlin Refinery (Cooling) 7 N/A
Enid, Oklahoma
Southwestern Public (Cooling) 80 160
Service Co.
Aniarillo, Texas
Cosden Oil & Chemical Co. 79 (avg) 742
Big Spring, Texas (Boiler Feed)
City of Denton (Cooling) 80 100
Texas
Southwestern Public 144 160
Service Co., Lubbock, TX
(Cooling & Boiler Feed)
El Paso Products Co. 125 550
Odessa, Texas
(Cooling & Boiler Feed)
Texaco, Inc. (Cooling) 90 194
Amarillo, Texas
/mil gal = 0.003785/mil cu m
0
0
143
N/A
N/A
225
N/A
240
821
180
304
675.
284
23
-------
information indicated that such
activities could be conducted with-
out health hazard. The lakes are
now used for boating and fishing
with associated activities along the
shoreline but are not open for whole-
body , water-contact sports. In
1965, an area adjacent to one of the
lakes was equipped with a separate
flow-through swimming basin which
used reclaimed water that was given
additional treatment by coagulation,
filtration, and chlorination.
The best documented tertiary
treatment process in the nation is
found at Lake Tahoe, California,
where five tertiary treatment steps
are combined to provide excep-
tionally high-quality effluent.
Activated sludge effluent is sub-
jected to chemical treatment for
phosphate removal, nitrogen removal,
filtration, carbon adsorption, and
chlorination. This plant also util-
izes advanced sludge handling tech-
niques, lime recalcination, and
carbon reactivation. The treated
effluent is pumped 14 miles (22.5
km) through a lift of 1,460 ft
(446 m) and then flows through
gravity pipeline an additional 13
miles (20.9 km) to Indian Creek
Reservoir. Indian Creek Reservoir
has a capacity of 3,200 acre-ft
(3,947,200 cu m). It is approved
for body-contact sports (swimming)
and is reported to boast excellent
trout fishing.
An interesting new project is
located at Lancaster, California,
where, since 1971, the Sanitation
Districts of Los Angeles County have
sold renovated wastewater to the
County of Los Angeles for use in a
chain of three recreational lakes.
The lakes have a capacity of 80 mil
gal (302.8 1) and serve as a focal
point for the County's 56-acre
(22.7 ha) Apollo Park. The park,
located near Lancaster, California,
was opened to the public in 1973 and
features fishing, boating, and pic-
nic areas. Treatment of Lancaster
consists of a series of eight oxida-
tion ponds followed by flocculation
and sedimentation for removal of
phosphates, suspended solids and
algae, filtration to polish the
effluent, and chlorination.
Each of the three recreational
projects briefly described above is
unique but they share much in com-
mon. All have found it technically
feasible to consistently produce
effluent meeting drinking water
coliform standards. All practice
phosphate removal for algae control
and filter the effluent to reduce
turbidity. Many species of fish
have been grown successfully, in-
cluding trout.
DOMESTIC REUSE
Great controversy surrounds
the subject of domestic reuse of
wastewater for potable purposes.
Much less opposition is voiced to
non-potable domestic reuse; e.g.,
toilet flushing. It is not within
the scope of this paper to enter
into the controversy.
The only current example of
direct reuse for domestic purposes
in the United States is the non-
potable domestic reuse program
managed by the National Park Ser-
vices at Grand Canyon National
Park. The Grand Canyon domestic
reuse operation provides an average
of 30,000 gpd (113.6 cu m/day)
through a separate distribution sys-
tem for toilet flushing, car
washing, irrigation, construction,
and car watering. Major tertiary
treatment given the activated sludge
effluent is anthracite filtration
and heavy chlorination. Cost to
the user for the reclaimed water is
$1,000 per mil gal ($264,000/mil cu
m) to $1,750 per mil gal ($463,OOO/
mil cu m). This premium price can
be obtained because fresh water
sells for $2,450 per mil gal
($684,000/mil cu m) in the area.
GROUNDWATER RECHARGE
Groundwater recharge by perco-
lation or well injection is being
practiced at six sites in the U.S.
with three more about to begin.
Table 11 summarizes the operations.
24
-------
TABLE. 11
INVENTORY OF RECHARGE OPERATIONS
Location
Managing agency
Purpose of recharge
MGD
Camp Pendleton, CA U.S. Marine Corp.
Hemet, CA
Long Island, NY
Oceanside, CA
Orange County, CA
Palo Alto, CA
Phoenix, AZ
San Cleiuente, CA
Whittier, CA
Eastern Municipal Water
District
Nassau County Department
of Public Works -
U.S. Geological Survey
Water and Sewer Dept.
Orange County Water
District
Santa Clara Valley
Water District
U.S. Water Conservation
Laboratory
City of San Clements
L.A, County Flood
Control District
. Groundwater replenishment 4
. Salt water barrier
. Groundwater replenishment 2
. Groundwater replenishment 0.5
. Salt water barrier
. Treatment for reuse 6(3)
. Groundwater replenishment 15''
. Salt water barrier
. Salt water barrier 2^
. Treatment for reuse
. Treatment for reuse 15^'
. Salt water barrier 2
. Groundwater replenishment 25
(1)Operational 1975.
(2)Operational 1976.
(3)Present system temporarily provides 1 MGD for groundwater replenishment,
New 6 MGD program operational 1975.
-------
As groundwater supplies con-
tinue to be overdrafted, the prob-
lems of salt water intrusions and
depleted supplies will cause author-
ities to look toward wastewater
reuse with groundwater recharge, as
a viable, expedient, and financially
feasible alternative. Groundwater
recharge with treated effluent has
been shown to be an effective method
of repelling salt water intrusion
and in providing exceptional terti-
ary treatment for reuse. The use
of effluent for these purposes
should increase greatly in coastal
areas threatened by intrusion and in
the arid southwestern U.S.
Recharge by percolation has
several advantages over recharge by
well injection: standard quality
secondary effluent can be used suc-
cessfully, capital costs and opera-
tion and maintenance requirements
are minimal, and the soil provides
exceptional tertiary treatment under
proper operating conditions. Re-
charge by percolation is most suc-
cessful when: SS concentration in
effluent is low (<20 mg/1) ; infil-
tration rates are high ( > 2 ft/day);
and operation follows a cyclic
flooding-draining-drying schedule to
reduce surface clogging. Where per-
colation is not feasible (i.e., land
not available, infiltration rates
too low, etc.), well injection of
effluent promises to be effective in
repelling salt water intrusion and
replenishing groundwater basins.
The Palo Alto, Orange County, and
Long Island programs are all in
various stages of design and con-
struction. Successful well injec-
tion recharge requires high quality
tertiary effluent (e.g., BOD<5,
SS < 1, P04 < 1, FE < 0.5, JTU < 0.3
units) usually achieved with chemical
coagulation/settling, ammonia
stripping or nitrification-denitrifi-
cation, filtration, and carbon ad-
sorption. Full scale recharge by
well injection should be preceded by
extensive pilot studies to determine
the hydraulic characteristics of the
receiving aquifer. This is necessary
to quantify the flow volume the
aquifer can handle, the directions
and velocities of underground flow,
and the quality of effluent necessary
to prevent clogging. Although well
injection recharge is very expen-
sive, involving extensive tertiary
treatment and a deep well network,
it is still economically attractive
if it successfully repels salt water
intrusion and/or supplements domes-
tie suppiies -to—eliminate or delay
the need to develop costly alternate
fresh water sources.
Both percolation and injection
recharge systems can be operated in
conjunction with extraction facili-
ties to ensure that none of the
effluent mixes with native ground-
water. The high quality extracted
water having received further treat-
ment by migration through the soil
can be reused for irrigation, recre-
-atron, or industrial purposes.
RECLAIMED WASTEWATER MARKET
CONSIDERATIONS
Obviously, a municipal waste-
water reuse program must have custo-
mers for its reclaimed water to be
successful. It appears from the
results of this study that generally
municipalities have not sought out
potential reusers, particularly
among private industry. Rare is the
municipality which thinks of its
effluent as a commodity to sell
rather than a nuisance to waste.
Yet, reused water has enormous poten-
tial for increasing the water
resources of individual localities
and the nation. If reclaimed waste-
water is used to satisfy demands for
non-domestic uses of water wherever
feasible, the fresh water thus saved
will be able to satisfy much of the
future increase in demand for general
water supply.
One of the first places for a
municipality to look is at its own
municipal activities. Municipal
power generation stations, golf
courses, parks, school grounds,
farms, and recreational lakes are all
successfully using their own treated
municipal effluent as a water supply.
Other governmental agencies, e.g.,
county, state, and federal, are also
excellent prospects to purchase
reclaimed water.
26
-------
Private irrigation reuse sales
opportunities are prevalent in most
areas. Private farms, orchards, and
golf courses are all amply repre-
sented among existing reusers. Most
of the existing irrigation reuse
operations are located very near the
treatment plant. It-.-appears that
more emphasis might be given to
selling effluent to large irrigators
remote from the treatment plant.
There are only eleven private
industrial reusers of municipal ef-
fluent in the nation, and two of
these are "company towns" for large
copper mines. Undoubtedly, many
opportunities for industrial reuse
of municipal wastewater are being
ignored, especially for cooling pur-
poses. AS the results of this study
amply demonstrate, municipal efflu-
ent can be successfully used for
both once-through and recirculating
cooling systems. There is extra
cost to the industry in treatment
and chemicals in the use of re-
"claimed water instead of fresh water;
however, in many cases, this extra
'cost is offset by the lower cost of
the used water. The potential mar-
ket is staggering. The power indus-
try alone uses over 75 bil gal per
day (283.9 bil I/day) of cooling
water.
Only a small percentage of
municipal wastewater is presently
reused in this country. To conserve
our national fresh water resources,
government and the public will be
wise to strongly support the ex-
panded practice and continued devel-
opment of municipal wastewater
reclamation.
ACKNOWLE DGMEN T
This paper summarizes the
results of the effort performed by
SCS Engineers under Contracts
68-03-0148 and 68-03-2140 to the
National Environmental Research
Center of EPA Cincinnati.
DISCUSSION
QUESTION: Mr. Henry J. Ongerth, Cali-
fornia Department of Health, Berkeley,
California. You have identified park and
golf course irrigation as irrigation rather
than as recreation.
RESPONSE: Mr. Schmidt. , Yes, absolutely.
Thanks. That's a good question. Recrea-
tion was only recreational lakes.
COMMENT: Mr. Robert B. Dean, Advanced
Waste Treatment, US-EPA, Cincinnati, Ohio.
There is a perfectly deliberate bias in
your whole survey in that you don't include
water that has been discharged to a stream.
I understand that this was necessary, but
the conclusion is biased because there are
many places in the arid Southwest where
the water goes into a stream which is dry
and it disappears into the groundwater.
This is unprogrammed groundwater recharge;
it is nevertheless groundwater recharge.
In California, at Dublin, they were put-
ting extremely tight standards on their
water because they knew it was all running
into the dry wash and would turn up in the
Niles aqueduct. There's a lot of that.
So there is a lot more reuse than you give
us credit for.
RESPONSE: Mr. Schmidt. Thank you.
That's a very good point and very true.
COMMENT: Mr. John N. English, EPA,
Cincinnati, Ohio. I think that ground-
water recharge is potable reuse in that
Henry Ongerth with the State Health Depart-
ment of California is quite concerned
about the organics, and so forth, that are
getting into the groundwater.
RESPONSE: Mr. Schmidt. That's also a
very good point, John.
COMMENT: Mr. John N. English, EPA,
Cincinnati, Ohio. Groundwater recharge is
potable reuse. It may not be direct
potable reuse, but it's still potable reuse.
It is practiced in California and in other
areas. The state health people are con-
cerned, and that's one of the reasons that
we've got to talk about potable reuse and
its associated health effects and treat-
ment technology.
27
-------
I think that industrial use and agricul-
tural use are less expensive, and where
they will reduce water consumption and are
the best alternatives for that area, then
I think we ought to practice such uses.
However, I think potable reuse, whether it
is indirect, such as groundwater recharge,
or direct, is also important and is also
a viable area of concern. In fact, it is
an area about which the people of Califor-
nia and Denver are very concerned. They
may not have the cheaper alternative of
agriculture or industrial use.
You and Frank Middleton identified the
various uses and indicated the desirability
of using the water where it is most eco-
nomical, but there is a tremendous need for
information on potable reuse and anything
related to health effects.
RESPONSE: Mr. Schmidt. I agree com-
pletely, John. In essence, the point I
was trying to get across is that I don't
think we should lose sight of all the less
controversial reuse potentials while we
are pursuing the potable concept.
QUESTION: Mr. Lawrence Gallowin, Nation-
al Bureau of Standards, Washington, B.C.
Did you discover any information relative
to nutrient values in agricultural reuse
and the possible impact on fertilizer re-
quirements?
RESPONSE: Mr. Schmidt. Yes. As might
be expected, the municipal effluent does
provide fertilizer constituents to the
crops, and in a few cases where crops were
irrigated with both municipal effluent and
fresh water on a more or less side-by-side
basis, in every case the crops irrigated
with municipal effluent did better.
COMMENT: Mr. Denny S. Parker, Brown &
Caldwell, Walnut Creek, California. From
one of your statements about the treatment
provided for cooling water, one might in-
fer that the only reason the lime treat-
ment was provided was for clarification.
Actually, lime treatment, in addition to
providing that clarification, also removes
phosphorus which can form a scale on heat
exchange surfaces. This is probably the
most universal reason for using lime treat-
ment in the cooling water sequence.
RESPONSE: Mr. Schmidt.
lutely right.
You are abso-
28
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WASTEWATER REUSE IN ORANGE COUNTY, CALIFORNIA
Neil M. Cline, Secretary Manager
Orange County Water District
and
David G. Argo, Assistant District Engineer
Orange County Water District
INTRODUCTION
In 1934 the Board of Directors of the
Orange County Water District in Orange
County, California adopted a resolution
that the Board "go on record as favoring
the reclaiming of all sewerage of Orange
County cities which is now going to the
ocean."
The Board had been in existence for
only one and a half years, and was wres-
tling with the problem of attempting to
find some supplemental water to replenish
the overdrafted groundwater basin. Water
levels in the County were dropping rapidly;
the upstream communities in the Santa Ana
River, the only significant replenishment
source, were diverting water in increasing
quantities; and seawater was encroaching
on groundwater supplies of the coastal
communities.
The usual eloquent argument was made—
that it was absurd to use water once and
dump this precious resource to the sea.
But the sum total of the resolution made
by our District forty-one years ago was a
cursory review of the state of the art of
salvaging wastewater, and it was determined
there were just too many unknowns to set
a direct course on reuse, and that alter-
natives would have to be developed, with
research conducted before reclamation
would be feasible.
Fortunately for Orange County, it
started raining in 1936 in unprecedented
quantities, and the water shortage problems
were overshadowed by floods and fear from
floods. In the meantime, The Metropolitan
Water District of Southern California com-
pleted its Colorado River aqueduct and
alternate sources of water were available
for local use. However, in the period
following World War II Orange County was
rapidly urbanized, the groundwater heavily
overdrafted, and seawater intruded inland
3-1/2 miles. To control further seawater
intrusion, groundwater replenishment was
instigated, and since 1949 the District
has placed over 2,000,000 acre-feet of
surplus Colorado River water in the basin
through surface spreading.
At the present time water supply in
the District is from the groundwater basin
through wells or by direct service from
The Metropolitan Water District of
Southern California. In 1974 the demand
for water in the District exceeded
300,000 acre-feet, of which over 200,000
were supplied from the basin and the
balance by direct service by MWD.
To further reduce intrusion and de-
velop greater flexibility in groundwater
utilization, in 1963 the Orange County
Water District began studies to develop
an effective hydraulic barrier. It was
concluded that as much as 30,000 acre-
feet per year could be required to operate
an efficient barrier and provide supple-
mental groundwater supplies to the rapidly
developing coastal cities within the Dis-
trict. The burning question was, where
would the District obtain 30,000 acre-
feet of noninterruptible source. The
Colorado River water supply was being
severely challenged by Arizona, the
Northern California water supplies were
a dream, and so once again the Board
turned to wastewater. Since 1963 the
District, in cooperation with the then
Federal Water Pollution Control Adminis-
tration, California State Department of
29
-------
Health, and the Orange County Health
Department, has been working to develop
and apply wastewater for barrier and water
supply purposes.
Following years of intense study, in-
cluding model and pilot plant operations,
in 1971 the District began construction of
Water Factory 21. This advanced waste-
water treatment plant will reclaim up to
15 mgd of secondary municipal treatment
effluent for blending with other waters
and injection, to form a barrier to sea-
water intrusion. At present, intermingling
of the injected water with potable ground-
water supply is being questioned by regula-
tory authorities due to various unknowns
which pose hazards to public health. The
questions are primarily concerned with
continuous reliability of plant operation,
ability of the processes to eliminate
human pathogens, and potential health
effects from organic materials remaining
in the reclaimed water. These questions
are of national interest and must be
answered before reclamation of wastewaters
for human consumption becomes a viable
alternative to water resources development.
There are several water-short areas in -the
United States where pressures for water
reclamation are great.
The goal of the Orange County Water
District as well as the cooperative and
regulatory agencies at County, State and
Federal levels, must be to establish con-
fidence in reusing wastewater for potable
purposes.
Sadly, in Orange County we are not in
a position today, as we were forty years
ago, to rely on rainfall to rescue us from
a prolonged drought. With the urbaniza-
tion of both upstream and local areas, the
runoff pattern has radically- changed and
we can no longer rely on substantial re-
plenishment through local storms. We are
committed to total water management, which
must include an increasing dependency up-
on imported supplemental water and waste-
water reuse.
To accomplish this goal, research
studies must be undertaken to gather sig^
nificant data in several areas of concern:
1. Demonstration of reliable and
fail-safe wastewater treatment
technology to enable control
of effluent variability and the
continuous production of potable
quality water.
2. The identification, measurement,
and monitoring of trace materials
(chemical, physical, and biologi-
cal) and residues in the effluent
from wastewater treatment systems
producing potable quality water.
3. Development of a more rapid virus
detection methodology, mandatory
to enable the water purveyor to
operate with the -confidence con-
sistent with national health
standards.
4. Intensive analyses of the effi-
ciency and feasibility of disin-
fectant and sterilization
methods, including an in-depth
review of chlorination and
ozonation practices.
5. A thorough study on the health
effects of high IDS and low TDS
waters. There are conflicting
research reports that are per-
plexing to the water purveyors,
and additional work is essential.
6. Continued and expanded research
to analyze the effects of ocean
discharge of sewage wastes.
7. Broadened research in sludge
disposal and mineral recovery.
8. Expanded development of programs
for alternate fuel sources to
lessen the energy impacts of
water salvage facilities.
WASTEWATER RECLAMATION AT
WATER FACTORY 21
The Orange County Water District
(OCWD) was formed in 1933 by special act
of the California Legislature. Under
this act, OCWD has the responsibility and
authority to provide:
1) Management of the groundwater
basin;
2) Conservation of the groundwater
supplies, including both quantity
and quality of the water; and
30
-------
3) Protection of Orange County's
water rights in the natural flows
of the Santa Ana River.
The District coders an area of about
315 square miles, generally overlying the
coastal basin of the Santa Ana River in
Orange County. Water supply within the
District is from the groundwater basin
through wells or by direct service from
the Metropolitan Water District of Southern
California (MWD). At the present time, the
total water use within the District is
about 300,000 acre feet per year; two-
thirds of this amount is supplied by the
underground basin and the remaining one-
third supplied through direct service by
MWD.
The growth rate of Orange County in
the transition from an agricultural to an
urban economy after World War II placed
large demands upon the groundwater supply.
The basin was overdrafted and by 1956
there was an accumulated overdraft in ex-
cess of 500,000 acre feet. Because of
this overdraft, seawater intruded inland
as much as 3 1/2 miles in the Talbert Gap
(the ancient channel of the Santa Ana
River). In 1948, OCWD began importing
Colorado River water and percolating it in-
to the groundwater basin through surface
spreading facilities in the Santa Ana
River. OCWD owns approximately 750 acres
of the Santa Ana River bed, and utilizes
the area for ponding imported water and
natural flows of the river to replenish
the underground basin. In addition, the
District owns two large off-river spread-^
ing basins of approximately 100 acres each.
This groundwater replenishment program by
surface spreading facilities has corrected
the dangerous overdraft conditions and has
provided an adequate groundwater supply
which has sustained the County's growing
economy.
Although OCWD has managed to place
enough water in the basin to keep the water
table at an adequate level to prevent wide-
spread damage from seawater intrusion,
saltwater has penetrated as far inland as
Garfield avenue in the Talbert Gap. To
prevent further intrusion in this location,
and to permit greater flexibility in the
management of the groundwater basin, OCWD
has under construction a barrier to sea-
water intrusion.
The feasibility and necessity of the
Orange County Coastal Barrier Project has
been reviewed by several agencies and a
summary report was prepared in 1967.
This report was presented to the Board of
Directors of the Orange County Water Dis-
trict at their meeting on January 18,
1967. At this same meeting, the Board
adopted Resolution No. 67-4, which re-
solved that the Orange County Coastal
Barrier Project is feasible and necessary.
The hydraulic barrier to seawater
intrusion will be composed of a series of
seven extraction wells (already construct-
ed and in operation) about two miles in-
land from the coastline and a series of
23 injection wells about four miles in-
land from the coastline.
OCWD reviewed the barrier project
Injection water requirements and con-
cluded that about 30 mgd (million gallons
per day) of injection water will be re-
quired; there are several possible sources
of supply for this injection water:
1. Imported water either from the
Colorado River or State Water
Project;
2. Water produced from a deep
aquifer not subject to seawater
intrusion;
3. Reclaimed wastewater;
4. Demineralized brackish ground-
water;
5. Desalted seawater;
6. Blend of the above waters.
A blend of reclaimed wastewater and
desalted seawater was selected for the
injection well supply. This blend will be
supplemented with deep groundwater as re-
quired. A 15 mgd wastewater reclamation
facility is being constructed with funds
provided by OCWD, the State of California
Water Resources Control Board and the
Federal Environmental Protection Agency.
A 3 mgd seawater desalting facility is
being constructed with funds from OCWD
and the Federal Office of Saline Water.
31
-------
Previous Studies
The Orange County Water District
(OCWD) has conducted an extensive applied
research and development program in waste-
water reclamation and groundwater recharge.
The program began in July 1965 and has
progressed in four phases. The first
phase was concerned with the feasibility
of treating trickling filter effluent for
injection through wells into a confined
aquifer system. During this phase, a
study of treatment operations was con-
ducted in both laboratory and pilot scale
units. Treatment prior to injection into
one single-casing gravel packed well con^
sisted of clarification, filtration and
chlorination. The progress of the first
phase was reported by Hennessy, et al, (.1)
and the findings of the first phase were
reported in detail in a report (2) to
OCWD in 1967. The first phase was pri-
marily concerned with treatment methods,
and injection was not extensively studied.
The primary objectives of Phase Two were
to determine the long-term fate of in-
jected reclaimed water, and evaluate the
performance of a unique multicasing in-
jection well. During Phase Two, reclaimed
water was injected through two multi-cas-
ing wells for about ten months. The
travel of the injected water was monitored
by nine wells located 100 to 1,000 feet
from the injection wells. The progress
of this second phase work was reported by
Wesner and Baier, (3) and the final re-
port was published in October 1970. (4)
It was the general conclusion of these
Phase Two studies that additional treat-
ment was required prior to injection be-
cause color and odor persisted in inject-
ed water even after 1,000 feet of under-
ground travel. In July 1969, a report
was prepared that surveyed advanced treat-
ment, methods and recommended additional
pilot studies. (5)
Phase Three consisted of additional
pilot wastewater reclamation studies con-
ducted from May 1970 to June 1971. During
this phase, treatment in the pilot waste-
water reclamation facilities consisted
of: (1) chemical clarification; (2)
ammonia stripping; (3) recarbonation; (4)
mixed media filtration; (5) carbon adsorp-
tion; and (6) chlorination.
The purpose of Phase Three was to
develop design data for the full size
plant. Results of the pilot plant studies
reported by Wesner and Argo (6) concluded
that the above treatment scheme could pro-
duce a water suitable for groundwater re-
charge by injection. Table I shows typi-
cal quality for both the pilot plant in-
fluent and effluent. The source of the
pilot plant's influent was trickling fil-
ter effluent from the existing secondary
treatment plant of the Orange County
Sanitation District.
Purpose and Scope
The purpose of this report is to
summarize the District's past and present
activities in wastewater reclamation.
The report describes the treatment pro-
cesses required to utilize reclaimed
wastewater for an injection barrier supply.
The report presents the design criteria
for the various unit operations including
outline plans, construction costs and
estimated operation and maintenance costs.
The report also reviews the quality re-
quirements for the injection water estab-
lished by the regulatory agencies.
WATER FACTORY 21 - WASTEWATER
RECLAMATION FACILITIES
Basis of Design
Water from the reclamation plant will
be injected into the groundwater basin
and will eventually be withdrawn and re-
used for domestic, industrial and irriga-
tion purposes. Therefore, at the point
of withdrawal, the water must meet drink-
ing water standards. OCWD's test program
of treatment operations and injection has
defined the quality parameters desirable
for injection. Prior to injection, the
reclaimed wastewater will be blended with
desalted seawater and, if needed, water
produced from a deep aquifer not subject
to seawater intrusion.
It is necessary to reduce the con-
centration of dissolved organic material
to a low value to eliminate taste, odor
and color. Ammonia nitrogen will be re-
moved to lower the total oxygen demand
and to -make the water more amenable to
disinfection and phosphorous will be re-
moved to control algae growths in the re-
use system. Bacteria and virus should
not be present in the injection water and
the concentration of potentially toxic
elements will meet the U.S. Public Health
drinking water standards. Suspended
32
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TABLE I TYPICAL WATER QUALITY, PILOT WASTEWATER RECLAMATION PLANT INFLUENT AND EFFLUENT
CONCENTRATION
(mg/1 except odor and color)
Constituent
Influent
Effluent
Calcium
Magnesium
Sodium
Potassium
Bicarbonate
Sulfate
Chloride
Phosphate
Nitrogen
Organic
Ammonia
Nitrite
Nitrate
Total Dissolved Solids
Total Hardness
Suspended Solids
BOD
COD
MBAS
Threshold Odor No.
Color, Units
Arsenic
Barium
Cadmium
Chromium (hexavalent)
Copper
Iron
Lead
Manganese
Mercury
Selenium
Silver
Zinc
70
20
240
20
200
270
300
20
5
15
<
<
1200
255
30
30
50
3
50
30
0.00
<
0.01
0.10
0.09
Q.OO
<0.001
0.00
0.00
0.07
110
45
- 260
35
- 450
- 350
- 350
25
15
30
1
:1
- 460
80
80
- 200
4
100
50
- 0.01
:0.02
- 0.13
- 0.20
- 0.39
—
- 0.05
- 0.003
- 0.09
- 0.01
- 2.08
50 -
1 -
240 -
20 -
150 -
270 -
300 -
<1
<1
<2
<1
<1
1000 -
130 -
<1
<2
10 -
0.1
<2
<2
0.01
<0.02
0.000 -
0,00 -
0.02 -
0.05 -
0.00 -
0.05 -
<0.001 -
0.000 -
0.00 -
0.02 -
80
3
260
35
170
350
350
1100
210
30
0.005
0.04
0.30
0.25
0.04
0.10
0.003
0.003
0.01
0.07
33
-------
solids in the injection water should be
as low as possible to minimize well clog-
ging. The California State Water Resources
Control Board, Santa Ana Region, and the
State Department of Public Health have
established requirements for the injection
water. These requirements are shown in
Table 2. The State Health Department also
requires monitoring for viruses.
Existing Sewerage System
All but the southeasterly portion of
OCWD lies within the service area of the
County Sanitation Districts of Orange
County. At the present time, there are
seven sanitation districts which own and
maintain about 400 miles of major trunk
sewers with more than 20 pump stations.
Jointly, the seven districts operate two
treatment plants to process wastewater for
ocean disposal. Treatment Plant No. 1 is
located about four miles from the coast
adjacent to the Santa Ana River and has a
capacity of 50 mgd. This plant gives pri-
mary treatment to all of the flow, and
secondary treatment by trickling filters
to 15 mgd. It is this secondary treated
effluent which is available to OCWD for
reclamation and an injection barrier sup-
ply. The quality of the trickling filter
effluent from Orange County Sanitation
District's Treatment Plant No. 1 is shown
in Table 3.
Water Factory 21's Plant Flow and Treatment
Sys tern
The wastewater reclamation process
consists of:
1. Chemical clarification for phos-
phorus and suspended solids re-
moval. This process also removes
some calcium, magnesium and trace
metals.
2. Ammonia stripping for nitrogen
removal.
3. Recarbonation for pH control and
additional removal of calcium.
4. Filtration for additional suspend-
ed solids removal to produce an
effluent with turbidity less than
1.0 Jackson Turbidity Unit (JTU).
5. Activated carbon adsorption for
removal of soluble organics -
the compounds which cause taste,
odor and foam.
6. Chlorination for destruction of
bacteria and virus.
7. Blending with desalted seawater.
8. Lime sludge recalcining and re-
use.
9. Activated carbon regeneration
and reuse.
Figure 1 is a schematic flow diagram with
the treatment system divided into liquid
processing and solids handling. The major
design criteria for Water Factory 21's
wastewater reclamation facilities are
summarized in Table 4.
Chemical Clarification
The primary purpose of the chemical
clarification system is to remove sus-
pended solids and phosphorus, but this
process also serves several other impor-
tant functions including:
1. Removal of some potentially toxic
trace elements.
2. Reduction in calcium and magne-
sium which contributes to water
hardness. The total dissolved
solids content of the water is
also reduced through the removal
of these elements.
3. At least partial disinfection of
the water occurs due to the fact
that the pH is -maintained at
about pH 11.0 for a period of
about one and a half hours. This
will produce a substantial reduc-
tion in bacteria and virus.
4. Elevation of the pH to about pH
11.0 which is necessary for
efficient ammonia stripping.
There are four major components of the '
chemical clarification system: rapid
mixing, flocculation, settling, and ef-
fluent pumping. Figure 2 shows an iso-
metric view of the chemical clarification
system.
34
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TABLE 2 REGULATORY AGENCY REQUIREMENTS FOR INJECTION WATER
CONSTITUENT
MAXIMUM CONCENTRATION
(mg/1)
Ammonium
Sodium
Total hardness (CaCOo)
Sulfate
Chloride
Total nitrogen (N)
Fluoride
Boron.
MBAS
Hexavalent chromium
Cadmium
Selenium
Phenol
Copper
Lead
Mercury
Arsenic
Iron
Manganese
Barium
Silver
Cyanide
Electrical conductivity
PH
Taste
Odor
Foam
Color
Filter effluent turbidity
Carbon adsorption column
effluent COD
Chlorine contact basin
effluent
1.0
110.0
220.0
125.0
120.0
10.0
0.8
0
0
.5
.5
0.05
0.01
0.01
0.001
1.0
0.05
0.005
0.05
0.3
0.05
1.0
0.05
0.02
900 umhos/cm
6.5 - 8..0
None
None
None
None
1.0 JTU
30 mg/1
Free chlorine residual
U.S EPAHeadquerie
-------
TABLE 3 SECONDARY EFFLUENT QUALITY _ ORANGE COUNTY SANITATION DISTRICTS TREATMENT
PLANT NO. 1
Constituent CONCENTRATION, mg/1
Calcium 70 - 110
Magnesium 20 - 45
Sodium 240 - 260
Potassium 20 - 35
Bicarbonate 200 - 450
\Sulfate 270 - 300
Chloride 300 - 350
Phosphate 20 - 25
Nitrogen
Organic 5 - 15
Ammonia 15 - 30
Nitrite < 1
Nitrate < 1
Total Dissolved Solids 1200 - 1400
Suspended Solids 30 - 80
BOD 30 - 80
COD 100 - 200
MBAS 3 - 4
36
-------
LIQUID PROCESSES
CHEMICAL
CLARIFICATION
r— RAPID MIXERS
\ r— FLOCCULATORS
\ 1 y- CHEMICAL
\ 1 \ CLARIFIERS
\ \\
\^~
il l
r- INFLUENT
PUMP
STATION
1
//
TOWER
PUMP
STATION
*r-
I
s
LIME f
SLUDGE — -^rn
PUMPS ^*"| |
LIME f
SLUDGE . ^~|
THICK- *- I
FHFS I
Y
SLUDGE . r^-l
PUMPS *T__J
A
V
CENTRIFUGES*-^)
Y
LIME
BFII«F RECALCINING
J% fc FURNACE
LIME RECOVERY
1
NITROGEN
REMOVAL
AMMONIA
STRIPPING
TOWERS
LIME
SLUDGE
}—- -H
1- 1
RECYCLED FILTER
RECARBONATION
.
RECARB-
ONATION
BASINS
— J
. : 1
WASH WATER
FILTRAHON
PUMP
STATION —i
FILTERS
I
WATER
RECEIVING
BASIN
*— RECYCLE
PUMPS
REGENERATED ,
CARBON TO REUSE
ACTIVATED
CARBON
ADSORPTION
CARBON
COLUMNS ^A
\
Y
.SPENT
/CARBON
.
-^^1
Y
CARBON
FURNACE
QUENCH) 1
TANK 1 1
CARBON JL
SLURRY ( J
PUMPS |T
. H
CARBON
REGENERATION
DISINFECTION
BLENDING
RESERVOIR—,
*
.. 1
•«- gm -
4
*— CHLORINE
CONTACT 1
TANK »
— CARBON DEWATER ING
TANKS
CARBON
^^
Y
SOLIDS HANDLING
FIGURE NO. 1
FLOW SCHEMATIC 15 MGD WASTEWATER RECLAMATION PLANT
37
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TABLE 4 MAJOR DESIGN CRITERIA, OCWD 15 MGD WASTEWATER RECLAMATION PLANT
INFLUENT PUMP STATION
Number of pumps: 2
Capacity: 6500 gpm @ 29 ft TDK 7000 gpm @ 27 ft TDK
Type: Vertical mixed flow
CHEMICAL CLARIFICATION SYSTEM
Rapid Mixing
Number of basins: 2 in series
Mechanical mixer in each, basin
Dimension: length = 12 ft; width = 12 ft; depth = 12 ft
Detention time: 2.4 minutes total @ 15 mgd
Chemical addition: First basin - lime, alum, recycled lime sludge
Second basin - polymer
Flocculatlon
Number of basins: 2, three compartments each.
Detention time: 10 min/compartment (30 min total) @ 15 tngd
Chemical addition: Polymer, 1st and 3rd compartments
Dimensions: length = 48 ft; width = 41 ft; depth = 11 ft
Flocculator mechanism: Oscillating type
Settling Basins
Number of basins: 2 rectangular
Dimensions: 120 ft long X 40 ft wide, each.
Surface Overflow Rate: 1563 gpd/sq ft @ 15 mgd
Each basin equipped with settling tubes
Clarifier Effluent Pump Station
Number of pumps: 4
Capacity: 3300 gpm @ 75 ft TDK; 3500 gpm @ 65 ft TDK
Discharge: To ammonia stripping tower or to the OCSD plant or to the
recarbonation basins
Lime Feeders and Slakers
Number: 2 gavimetric feeders and paste type slakers
Capacity: 4000 Ibs/hour each
Polymer Feed System
Number of mixing tanks: 2 (900 gallons each)
Number of feed pumps: 4
Capacity: 5 to 50 gph each.
Alum Feed System
Number of storage tanks: 2 (4,100 gallons each)
Number of feed pumps: 3 (.2 double head and 1 single head)
Capacity: 25 gph each head
38
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TABLE 4 (CONTINUED)
AMMONIA STRIPPING/COOLING TOWERS
Number of towers: 2
Dimensions: length - 207 ft; width = 61 ft; depth of packing = 25 ft
Capacity: 5200 gpm each @ 0.1 gpm/sq ft
Number of fans: 6 per tower, 18 ft diameter, 2 speed electric motors
Air Capacity: 2,100,000 cfm/tower (400 cfm/gpm)
Hot water streams: Tower No. 1 - 8,000 gpm cool 115°F to 80°F
Tower No. 2 - 11,000 gpm cool 120°F to 85°F
RECARBONATION
Number: 2 (3 compartment basins: 1st stage recarbonation, intermediate
settling, 2nd stage recarbonation)
Detention Time, 1st and 2nd stage recarbonation: 15 minutes each
Overflow rate, intermediate settling: 3000 gpd/sq ft @ 15 mgd
FILTRATION
Number of filters: 4
Dimensions: 22 ft X 24 ft
Type: open, gravity, mixed media
Hydraulic loading rate: 5 gpm/sq ft @ 15 mgd
Maximum operating head loss: 10 ft
Filter aids: alum and polymers
Backwash system: Hydraulic with rotating surface wash arms
Backwash rate — 15 gpm/sq ft
Surface wash rate - 0.6 gpm/sq ft
Backwash water receiving tank volume: 160,000 gallons
ACTIVATED CARBON ADSORPTION
Number of contactors: 17
Normal Service: 16 in parallel operation, 1 for carbon storage and
standby service
Type: Upflow, countercurrent, in steel pressure vessels
Dimensions: Overall height = 41 ft; sidewall height = 34 ft; Diameter => 12 ft
Contact Time: 30 minutes at 15 mgd
Carbon Size: 8 X 30 mesh
CHLORINATION
Number of contact basins; 1
In-line feeding and mixing
Contact Time: 30 minutes
Chlorine Feeders: 3 C20QO Ibs/day each)
On site generation of chlorine: 2,000 Ibs/day
CHEMICAL SLUDGE TREATMENT AND RECOVERY SYSTEMS
Sludge Pumps
Number: 3
Capacity: 500 gpm to 700 gpm
Influent solids capability: 5% maximum
39
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TABLE 4 (CONTINUED)
Sludge Thickener
Number: 1
Dimensions: 45 ft diameter, 8 ft 4 in sidewater depth
Loading: 600 gpd/sq ft @ 1.5% solids from clarifier at flow of 15 mgd;
dry solids loading = 75 Ibs/sq ft/day
Thickened sludge concentration: 8 to 13% solids
Thickened Sludge Pumps
Number: 3
Capacity: 80 gpm at 60 ft head each, variable speed
Influent solids capability: 18% maximum
Centrifuges
Number: 2
Capacity: 2,000 Ibs/hour each
Feed Rate: 54 to 105 gpm
Recalcining Furnace
Number: 1, 6 hearth
Dimensions: 22 ft 3 in. OD; 20 ft 0 in. ID
Capacity: 0.4 to 2.0 tons/hour; 30 tons/day dry CaO
Scrubber; 3 stage jet impingement
Fuel: natural gas
Lime Storage Bins
Number: 2
Capacity: 35 tons each
Dimensions: 12 ft 6 in. diameter by 15 ft 1 in. storage depth (overall
height = 28 ft 6 in.)
Carbon Dioxide Compressors
Number: 3
Capacity: 1,600 cfm (12% CO ) each
ACTIVATED CARBON REGENERATION
Regeneration Furnace
Number of furnaces: 1, 6 hearth
Dimensions: 9 ft 3 in. OD, 7 ft ID
Capacity: 2,000 to 12,000 Ibs/day (dry basis)
Steam Addition: No. 4 and No. 6 hearths (optional); 1 Ib steam per Ib carbon
Air Pollution Control:
Scrubber: Venturi followed by water separator
Afterburner: Vertical, refractory lined steel, 1400°F at 0.5 seconds
minimum gas retention time
40
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TABLE 4 (CONTINUED)
Carbon Wash and Transfer Tanks
Number: 2
Dimensions: 5 ft diameter by 10 ft high
Equipped with bag dump and dust collector
Regenerated Carbon Wash Tanks
Number: 2
Dimensions: 5 ft diameter by 10 ft high
Spent Carbon Dewatering Tanks
Number: 2 (open top) :
Dimensions: 5 ft X 5 ft X 14 ft 6 in. high
Furnace feed system: 12 in. diameter screw conveyor, stainless steel
with capacity of 80 to 500 Ibs/hr on a dry basis
Carbon Slurry Pumps (transfer carbon from regeneration furnace 'to carbon wash tanks)
Number: 2
Type: Diaphragm slurry, air operated, 3 in. suction and discharge
Capacity: 500 gpm with 4:1 turndown ratio
41
-------
NJ
PLANT
INFLUENT
LINE
CLARIFIFR
EFFLUENT
PUMP STATION
SETTLING BASINS
FIGURE NO. 2'
CHEMICAL CLARtFICATiON BASIN
-------
Rapid Mix
Secondary trickling filter effluent
is pumped from OCSD into the first rapid
mix basin where lime, in slurry form, is
added and mixed. The rapid mix basins are
equipped with removable mechanical mixers
to facilitate cleaning. The rapid mix de-
tention time at plant design flow (15 mgd)
is 2.4 minutes total.
Liquid alum and recycled lime sludge
can also be added to the first basin if it
is determined that either or both will im-
prove floe formation and settling. There
are also provisions for addition of poly-
mer to the second rapid mix basin.
Lime feed to the rapid mix basin is
accomplished by two gravimetric lime feed-
ers and paste type slakers. Water is added
to the slaked lime to form a slurry and the
slurry flows to the rapid mix basin in a
flume. One feeder is for makeup lime, the
other is for recalcined lime. Usually
both machines will be in operation, but, if
necessary, either one alone can treat the
entire plant flow. The feed rate can be
adjusted manually or it can be paced to
plant flow rate by means of an automatic
pacing device.
There are four polymer feed and meter-
ing pumps which can be automatically paced
to flow. It is anticipated that good floc-
culation, clarification, and phosphorus
removal will be accomplished using lime as
the primary coagulant and a polymer as a
coagulant aid. It is anticipated that
only under unusually difficult circumstances,
if ever, will it be necessary to add alum
to the rapid mix basin.
Flocculation
The chemically treated secondary ef-
fluent flows from the rapid mix basins to
a distribution channel where the flow is
divided into two parallel flocculation
basins. Each flocculation basin normally
treats one^half the flow. One basin can
be taken out of service- by closing the
sluice gates in the distribution channel.
Each basin is divided into three bays or
compartments and each bay contains an
oscillating paddle type mixer. The deten-
tion time in each bay is ten minutes. The
oscillating paddle mixers are variable
speed to allow independent control of
mixing energy in each bay. Normally the
paddle speed is fastest in basin no. 1
and slowest in basin no. 3.
Settling
Water flows from the bottom of the
flocculation basin and enters near the
bottom of two parallel settling basins.
Water flows horizontally and up through
settling tubes over notched weirs and out
through collection troughs to the clari-
fier effluent pump station. The settling
basins design overflow rate is 1563 gpd/
ft2 @ 15 mgd. Solids settle to the bot-
tom and are removed continuously by three
mechanical scrapers in each basin. The
settled solids then flow by gravity to
the sludge pump station.
Clarifier Effluent Pump Station
The chemically clarified effluent
flows by gravity to the pump station
located at the south end of the settling
basin. The pump station is divided into
two separate sumps and each, sump is
equipped with two pumps. Effluent from
the chemical clarifier can be pumped to
any- one of three places:
1. Ammonia stripping towers
2. Returned to the OCSD plant for
ocean disposal
3. The recarbonation basin (bypass
the ammonia stripping towers).
The chemical clarifier effluent can be
returned to the OCSD plant through control
valves in each of the clarifier effluent
pump discharge lines. It will be neces-
sary to return the clarifier effluent to
OCSD for a few hours after start-up of
the clarifier. The clarifier effluent
turbidity should be less than ten JTU for
the subsequent unit operations to per-
form efficiently. During start-up, the
clarifier effluent turbidity is initially
too high; also, occasionally, upsets in
the secondary treatment or equipment fail-
ures may necessitate returning the flow to
OCSD.
A control circuit is provided to
automatically return the clarifier ef-
fluent to the OCSD plant when the turbid-
ity of the clarifier effluent is above
43
-------
the normal range. This normal range is
adjustable and the circuit can either be
activated or deactivated by a panel-
mounted switch. Flow will be pumped to the
ammonia stripping towers when the turbid-
ity is within the normal range.
Ammonia Stripping/Cooling Towers
The two ammonia stripping/cooling
towers serve the dual purposes of removing
nitrogen in the form of ammonia gas from
the lime clarified wastewater and cooling
two warm water streams from the seawater
desalting process. An illustrative sec-
tion of the towers is shown in Figure 3.
Tower No. 1 cools process water from
115° to 85°F. This process water is re-
turned to the desalting plant. Tower No.
2 cools waste brine from about 120° to
85°F, prior to discharge in the ocean
through OCSD's outfall. In the water cool-
ing operations, the inlet air to the am-
monia stripping units will be heated to,
approximately 90°F and the warm air will
increase the efficiency of the ammonia
stripping process. The ammonium ions pre-
sent in the secondary effluent are con-
verted to ammonia gas when the pH of the
wastewater is raised to 10.8 to 11.5. The
ammonia gas can then be removed from the
wastewater by air stripping.
Each of the six cells in each tower
is equipped with a two speed fan capable
of a maximum air capacity of about 350,000
cfm. This provides an air to water ratio
of 400 ft-Vgal of wastewater. Air is
drawn into the tower through the separate
cooling sections which are located at the
lower outside faces of the towers. Air-
flow passes up through the packing (counter-
current to water flow) for air stripping
of ammonia from the water droplets as they
are formed by the splash bar packing. The
splash bar packing is arranged in removable
modules. The modules are 6x5x4 feet.
The arranged modules are stacked six high
in each cell for a total packing depth of
25 feet. The air exhausts through the fan
stacks on top of the tower structure.
Chemical clarifier effluent is pumped
to the top of the towers and a pressure
header in each tower distributes the flow
through spray nozzles to the cells. Each
tower has six cells and each cell is equip-
ped with two, 12 ft. wide packing sections
which are separated by an interior central
access area and flanked by exterior access
areas. Water flows down through the pack-
ing sections at the rate of 1 gpm/ft2 of
packing area through either of two lines
which serve the respective towers, to the
recarbonation basin.
Water or airflow can be shut off to
any individual cell. Five of the six
cooling cells in either tower are adequate
for the cooling duty, so that any one cell
can be taken out of service as necessary
for maintenance.
If scale builds up excessively on
the ammonia stripping packing, the pack-
ing modules may either be cleaned by
hosing in place or it may be removed, by
means of the equipment provided, for ex-
ternal cleaning by hydraulic or mechani-
cal means. By cleaning only one cell of
the tower at a time, the other five cells
can remain in service. The system is
also equipped with facilities to add a
descaling polymer to the tower influent
if needed.
Recarbonation
The primary purpose of the recarbon-
ation basin is to inject carbon dioxide
(C02) gas into the wastewater to lower
the high pH resulting from the lime treat-
ment in the chemical clarifier. The two-
stage system with intermediate settling
also provides for maximum recovery of
calcium and reduces the total dissolved
(IDS) content of the water below that
which would result from the same pH re-
duction in a single stage. The recarbon-
ation basin is shown in Figure 4.
The flow into the first recarbonation
basin is usually by gravity from the am-
monia stripping towers, although flow may
be pumped directly from the chemical
clarifier if the stripping towers are not
in service. Flow enters the first stage
recarbonation basin where enough CC>2 is
injected to lower the pH to about 10.2.
The first stage recarbonation basins are
equipped with mechanical flocculation de-
vices which are identical to those in the
chemical clarifier flocculation basins.
The C02 is obtained from the recalcining
furnace stack gas and is injected through
a 4 in. PVC perforated pipe which serves
as a diffuser. A standby connection is
44
-------
AIR OUTLET
FAN STACK
WATER INLET FLOW
CONTROL VALVE
WATER
DRIFT
ELIMINATOR i
AMMONIA
REMOVAL
FILL BUNDLES
POOLING FILL
AND AIR INLET
WASTEWATER-
COLLECTION
CHANNEL
COOLED PROCESS-
WATER OR BRINE
COLLECTION CHANNEL
FIGURE NO. 3
AMMONIA STRIPPING TOWER
45
-------
SECOND STAGE
RECARBONAT10N
AMMONIA
TOWER
EFFLUENT
CO DISTRIBUTION
LINES
FIGURE NO. i\
RECARBONATION BASIN
EFFLUENT TO FILTRATION
CHAIN BUILDING)
FIRST STA6E
RECARBONATION
CO DISTRIBUTION
LINES
-------
provided for emergency use of pure liquid
CC>2 which would be purchased in a bulk
storage tank. A foam control spray is
provided in this basin.
The flow then passes through slots
along the bottom of a common wall into the
intermediate settling basin where the cal-
cium carbonate (CaCOg) floe is allowed to
settle. Each of the two intermediate
settling basins is equipped with mechani*-
cal sludge scrapers. Most of the settled
sludge - which is almost pure CaCC>3 *• is
pumped to the lime recalcining system,
although a small portion may be recycled
to the chemical clarifier rapid mix basins
to aid the clarification process.
The effluent from the settling basin
is collected in four launders in each
basin and conveyed to the adjacent secon-
dary recarbonation basin where additional
CO- is injected to lower the pH to near 7.
The final recarbonated effluent then flows
by gravity to the filter distribution box.
The pH of the recarbonation basin effluent
is continuously monitored to provide con-
trol of the process.
Filtration
It is the purpose of the filtration
system to provide the maximum water clarity
achievable. This is important for several
reasons: (1) the discharge requirements
specify that the product water turbidity
not exceed 1 JTU, (2) filtration ahead of
carbon adsorption reduces the load of or-
ganics, suspended solids, and colloidal
matter reaching the carbon which increases
carbon efficiency and reduces carbon foul^-
ing, and (3) the effectiveness of disin-
fection by chlorination is significantly
improved by removing particulate matter
which otherwise may encapsulate virus and
bacteria, preventing the necessary contact
with the chlorine.
The recarbonation system effluent
passes through four open, gravity, down-
flow filter beds which operate in parallel.
Figure 5 shows a cross-sectional view of
the filters including the pipe gallery-
Each bed has a capacity of 3.75 mgd at a
throughput rate of .5 gpm per square foot
of surface area. The filters are the mixed
media type which provide coarse-to-fine
filtration in the direction of flow. The
filter media (30 inches deep) is made up
of coarse coal, medium sand and fine
garnet.
As a filter operates in removing sus-
pended matter from the wastewater, the
headless or pressure drop increases.
Eventually the headless reaches the point
(about 10 feet) that the filter must be
backwashed to remove the accumulated
solids. Normally the filters are back-
washed for about six minutes at a rate of
15 gpm per square foot (7,920 gpm). In
addition, the filters are equipped with
rotary surface wash devices.
All backwash water and all water
following backwash, when the filter is
operated in a filter-to-waste mode, flows
to the backwash water receiving tank.
From there the backwash water is recycled
back to the rapid mix basins and recovered.
Generally, following the backwash opera-r
tion, the filter is operated in the
filter-to--waste cycle for about 15 to 20
minutes as determined by the filter ef-
fluent turbidity. For best virus removal
by chlorination, it is desirable to
filter-to-waste until the turbidity of
the effluent is less than 0.2 JTU before
returning the filter to service.
Filtered water flows to a basin in
the main building. The filtered water
ba,sin sump is equipped with two sets of
pumps which pump effluent to the activated
carbon columns and also provide water to
the plant water supply system.
Activated Carbon Adsorption
The filtered effluent is pumped to
columns of granular activated carbon. .In
biological treatment of wastewater by
activated sludge or trickling filters,
some dissolved organic materials are re-
moved including most of those measured by
the BOD (biochemical oxygen demand) test.
These materials include MBAS (Methlene
blue active substances - primarily from
detergents), herbicides, pesticides,
tannins, lignins, ethers, proteinaceous
substances, and other color and odor pro-
ducing organics. It is the purpose of
the activated carbon adsorption process
to remove these organic materials which
are not adequately removed in the biologi-
cal process. Activated carbon adsorption
47
-------
24" BACKWASH
SUPPLY HEADER
30" FILTER
INFLUENT
HEADER
6" SURFACE WASH
SUPPLY HEADER
INFLUENT
VALVE
BACKWASH SUPPLY RATE
OF FLOW CONTROLLER
WASH
WATER
TROUGH
SURFACE
HASH
VALVE
FILTER
GULLET
BACKWASH SUPPLY
VALVE
FINE
FILTER
MEDIA
FILTER-TO-WASTE VALVE
FILTER
EFFLUENT
CONDUIT
BACKWASH WASTE VALVE
30'
WASTE DRAIN
FILTER EFFLUENT RATE
OF FLOW CONTROLLER
FIGURE NO. 5
mi MEDIA FILTER
48
-------
also has the ability to provide some re-
moval of trace inorganic metals such as
cadmium, chromium and silver.
The removal of soluble, refractory
organics is important because the organic
content of the reclaimed water should be
minimized to eliminate taste, odor and
foam, and the removal of organics reduces
the chlorine demand of the wastewater, re-
ducing the cost for effective disinfection.
There are 17 carbon adsorption columns,
16 of which operate in parallel, with the
remaining unit used for carbon storage and
stand-by service. The columns are upflow
pressure units. Water is introduced to
the column through the bottom inlet
screens, flows upward through the carbon
and leaves the column through the top
screens. The contact time is about 30
minutes (empty bed basis) at a flow of 15
mgd. The upflow columns are operated in
the current mode. Figure 6 is an illustra-
tion of a typical carbon column. The car-
bon columns are 12 feet diameter steel
epoxy lined tanks. Each tank contains
approximately 45 tons of granular activated
carbon.
Activated Carbon Regeneration and Reuse
About every 4-6 weeks it will be nec-
essary to thermally regenerate a portion
of the carbon. Granular activated carbon
removes detergents, insecticides, herbi-
cides and various organic substances which
contribute to the taste, odor and color
of the wastewater. As these substances
are removed by adsorption, the carbon in-
creases in weight and with continued use
eventually becomes saturated and loses its
ability to further adsorb organic mate-
rials . The carbon nearest to the inlet
(bottom) of the carbon column becomes satu-
rated and loses its ability to further
adsorb organic materials. The carbon
nearest to the inlet (bottom) of the car-
bon column becomes saturated or exhausted
first. The exhausted carbon at the bottom
of the column is removed for regeneration
and following regeneration is returned to
the top of the column (counter current
operation).
The purpose of the regeneration pro-
cess is to restore the adsorptive capacity
of the granular carbon. Regeneration is
accomplished by heating the carbon to
temperatures in excess of 1,500°F. The
heat vaporizes and drives off the impuri-
ties which have been adsorbed on the car-
bon and restores the carbon essentially
to its original activity.
When carbon in the bottom of a car-
bon column becomes saturated with impuri-
ties and no longer has capacity to adsorb
organics from the incoming wastewater, a
portion (one dewatering bin full or about
10 percent of the carbon in one column)
is withdrawn and discharged to a dewater-
ing bin. Carbon is transferred from one
container to another in slurry form.
About one gallon of water per pound of
carbon is required to form a suitable
slurry. A schematic diagram of the car-
bon regeneration and reuse system is
shown in Figure 7.
The dewatering bins are epoxy coated
to protect the steel against the corrosive
action of partially dewatered carbon. In
about ten minutes the free water will
drain from the carbon through the screened
drains. Because of the fine pore struc-
ture of the carbon, it still retains 40
to 45 percent moisture after draining and
this moisture content is about optimum
for its thermal regeneration. The par-
tially dewatered carbon is transferred
from one of the two dewatering tanks by
means of a variable speed, stainless
steel, screw conveyor at rates which can
be varied from 80 to 500 pounds per hour
(dry basis). The exhausted carbon is
discharged into the top of the carbon re-
generation furnace.
The carbon regeneration furnace is
a gas fired six hearth unit rated at
12,000 pounds per day of dry carbon.
There are six burners, two each on hearths
4, 5 and 6. The temperatures on these
hearths are independently regulated within
10°F by an automatic temperature control-
ler. Recording of all hearth temperatures
is also provided. Proportional flow
meters on the air-gas mixture lines to the
burners insure a constant percentage of
excess oxygen. The oxygen content of the
furnace atmosphere must be limited to
avoid everburning of the carbon. Each
burner may be adjusted to maintain 0 to
5 percent oxygen by volume. In addition,
steam can be added to hearths 4 and 6 to
give more uniform distribution of tempera-
ture throughout the furnace. The carbon
is moved across the hearths by four
rotating stainless steel rabble arms on
49
-------
INFLUENT
MANIFOLD
EFFLUENT MANIFOLD
8 EFFLUENT
2 EXHAUSTED
CARBON LINE
FLOW TUBE
FLOW CONTROL
VALVE
-24" EFFLUENT
HEADER
10 BYPASS
10 INFLUENT
8 DRAIN
FIGURE NO. 6
CARBON COLUMN
50
-------
EXHAUSTED CARBON SLURRY
CARBON
FILLING
CHAMBER
CARBON
COLUMN
PRESSURE
WATER
REGENERATED
•AND MAKEUP
CARBON SLURRY
MAKEUP
CARBON
CARBON
>DEWATERING
TANK
SCREW FEED
CONVEYOR
MAKEUP
CARBON
WASH
TANK
-t
\MAKE UP CARBON
SLURRY
X
PRESSURE
WATER
CARBON
REGENERATION
FURNACE
r
*—+-tu
SCREENED-,
OVERFLOW \
DRAIN
QUENCH TANK
REGENE-
RATED
fcARBON
WASH
TANK
PRESSURE
WATER
-H4
CARBON
SLURRY
PUMP
REGENERATED CARBON
"SLURRY
PRESSURE
WATER
FIGURE NO. 7
CARBON REGENERATION SYSTEM
51
-------
each hearth. Each arm is equipped with
stainless steel rabble teeth whidh are
oriented vertically. The rabble arms are
driven by a central shaft which is cooled
by an electrically driven fan so that the
exhaust cooling air temperature is 450° or
less. The exhausted cooling air is ducted
into the main exhaust stack to aid in dry-
ing the scrubber exhaust gases for plume
control.
The gases produced by carbon regenera-
tion leave the top of the furnace and en-
ter an afterburner which operates at
1,400°F to burn volatile and noxious gases.
The furnace is also equipped with a Venturi
type wet scrubber to remove carbon fines.
The scrubber water is returned to the
rapid mix basin for reprocessing.
The regenerated carbon is discharged
from the bottom of the furnace into a
quench tank for cooling. The carbon
slurry is pumped from the quench tank to
either of two regenerated carbon wash
tanks. After removal of fines in the wash
tanks, the carbon is transferred back to
the columns for reuse.
Chlorination
Effluent from the activated carbon
flows to the chlorination basin. The pur-
pose of chlorination is to destroy any re-
maining bacteria and virus and to remove
(by chemical oxidation) any remaining
ammonia. Figure 8 shows a plan view of
the chlorine contact basin.
Chlorine is added through a perforated
diffuser pipe in the 30-inch pipeline be-
fore it enters the chlorine contact basin.
Immediately after the diffuser, the flow
makes a 90° turn and passes over several
baffles. The purpose of this diffusion
and baffling system is to thoroughly mix
the chlorine solution with the carbon
column effluent. The contact basin is
baffled to provide a serpentine flow path
for the water. The theoretical detention
time in the basin is 30 minutes at a flow
rate of 15 mgd.
Blending and Storage Reservoir
Effluent from the chlorination basin
flows by gravity through a 30-inch line
to a one million gallon blending and stor-
age reservoir which is 100 feet in
diameter and 20 feet deep where it is
blended with desalted seawater and well
water.
The State Department of Public
Health requires that reclaimed wastewater
must be blended with at least an equal
amount of desalted seawater or deep well
water before it is injected. Water is
withdrawn from the reservoir through a
48—inch line for injection. Chlorine may
be added to the injection pump suction
line as it leaves the reservoir.
Injection Pump Station
This station contains three injection
pumps. Each injection unit is a vertical
turbine-can type pump with gas engine
variable speed drive rated at 4,000 to
7,200 gpm at 140 and 122 feet TDK, respec-
tively. These pumps take suction from
the blending reservoir and discharge into
the injection well supply pipeline.
The total injection flow is measured,
totalized and recorded at the main control
panel. The injection flow is controlled
by an injection header pressure indicating
controller. The output.of this controller
is used to proportionally control the
speed of the injection pumps. Control is
provided to match the injection flow to
the flow into the blending and storage
reservoir.
Injection Wells
There are 23 injection well stations
and all but one of these is contained in
an underground vault. Each station con-
tains 2, 3 or 4 well casings, each per-
forated in a different aquifer. A typical
injection station is shown in Figure 9.
The flow in each casing is individ-
ually adjustable with a manually operated
valve. Injection well flow and head are
transmitted for each well to the central
data logging system in the main building
control room.
Sludge Handling, Lime Recovery and Reuse
Chemical sludges are produced from
(1) the coagulation of the wastewater in
the chemical clarification process , and
(2) the recarbonation process. It is the
purpose of the chemical sludge system to
52
-------
Oi
u>
A >
*:'
wet*
seer/a*/
BAfflt
IkJ-LIKJE AIXIMG
T^>
0
^1 I
"im
*!
I
V
?O^j
PLAM
l'-
-------
TALBERT
AQUIFER
ALPHA
AQUIFER
BETA
AQUIFER
LAMBDA
AQUIFER
-REMOVABLE COVER
VAULT
GRAVEL
PACK
GROUT
INJECTION-
6" WELL CASING
PRESSURE
GAGE-x
-FLOW CONTROl
VALVE
INLET
-MANIFOLD
VAULT PIPING
INJECTION WELL
FIGURE NO. 9
INJECTION WELL
-------
collect, concentrate and dewater these
sludges so that lime can be recovered by
a thermal recalcining process and reused;
and the volume of residual waste materials
requiring disposal can be minimized.
Figure 10 is a schematic diagram of
the sludge handling and reuse system.
Sludge from the chemical clarifier
settling basins and the recarbonation set-
tling basins is pumped from the sludge
pump station to a gravity thickener.
Thickened sludge which is about 10 to 15
percent solids, is pumped to centrifuges
and dewatered to about 50 percent solids.
The dewatered sludge is transferred
by screw conveyor either to the lime re-
calcining furnace or to trucks for dis-
posal at the County dump. Reclaimed lime
is usually transferred by screw conveyor
to lime storage bin No. 1, but it can also
be transferred to bin No. 2. Lime is
withdrawn from the storage bins, fed to a
slaker and then transferred to the rapid
mix basin in an open flume.
There were six bids for the construc-
tion of Water Factory 21's reclamation
facilities. The bids were opened on March
14, 1972 and the total bid prices are
shown below:
RECLAMATION PLANT AND
CONTRACTOR DISTRIBUTION FACILITIES
A $11,705,900
B 12,655,160
C 13,181,000
D 13,805,000
E 13,988,600
F 14,357,000
The above bids include the distribution
pipeline to the injection wells, and the
well vaults and piping and other injection
well appurtenances. The maintenance build-
ing and laboratory for the plant are not
included in the above bids; also not in-
cluded is the chlorine generation system
or the fine filter media. Adding and de-
ducting the cost of these items makes the
total cost, including engineering design
and inspection, for the 15 mgd wastewater
reclamation facilities $11,924,000. A
breakdown of these capital costs by treat-
ment operation is shown in Table 5. The
estimated operation and maintenance costs
are shown in Table 6 and the total costs
are shown in Table 7.
The estimated costs of water produced
in the reclamation facilities are sum-
marized below:
WATER COSTS
$/acre $/million
foot gallons
Capital 57
Operation & Maint. 68
TOTAL 125
175
209
384
These costs are based on the following
assumptions:
1. Service life of facilities =
30 years;
2. Interest rate = 6%;
3. Facilities operate 330 days/year
and produce 15 mgd.
REFERENCES
1. Hennessy, P. V., et al., "Tertiary
Treatment of Trickling Filter Efflu-
ent at Orange County, California",
JWPCF, P. 1819, 1967.
2. "Report of Pilot Wastewater Reclama-
tion and Injection Study", James M.
Montgomery Consulting Engineers,
Inc., and Toups Engineering, Inc.,
Rept. to Orange County Water Dis-
trict, December 1967.
3. Wesner, G. M., and Baier, D. C.,
"Injection of Reclaimed Wastewater
into Confined Aquifers", JAWWA,
pp. 203-310, March 1970.
4. "Final Report on Injection Demonstra-
tion Program, 1969", by Orange
County Water District, October 1970.
5. "Recommended Advanced Wastewater
Treatment Investigation for Fiscal
Year 1969-70", by Toups Engineering,
Inc., July 1969.
6. Wesner, G. M., and Argo, D. G.,
"Pilot Wastewater Reclamation Study,
May 1970 - June 1971", Orange County
Water District, July 1973.
55
-------
Ul
EXHAUST
GAS
SCRUBBER
3 C0£ COMPRESSORS
CAKE TO FURNACE
TO
BACKWASH
WATER
RECEIVING
TANK
C02 TO
RECARBONATION
BASINS
TO CLARIFIER RAPID MIX.
BASIN NO.l
RECALCINING
FURNACE
CENTRATE
TO ——
SEWER
SLUDGE u
THICKENER
"^^^-^
LUDGE
I -(
^ i
«H
i4J
RECYCLE CENTRATE
RECALCINED LIME
^
r
LIME
STORAGE
BIN NO.l
^
r
LIME
STORAGE
BIN NO, 2
LIME
FEEDER
LIME
SLAKER
LIME
FEEDER
LIME
SLAKER
LIME SLURRY
TO RAPID
MIX BASIN
NO.l
SLUDGE FROM
CHEMICAL
CLARIFIER
SETTLING
BASIN
SLUDGE
PUMP
STATION
SLUDGE FROM
RECARBONATION
BASIN SETTLING
BASIN
FIGURE NO. 10
SLUDGE HANDLING SYSTEM
-------
TABLE 5 CAPITAL AND ENGINEERING COSTS
15 mgd Waste-water Reclamation Facilities
Orange County Water District
Land $ 200,000
Influent Pipeline & Pump Station 341,000
Clarification . 756,000
Ammonia Stripping 2,834,000
Recarbonation 381,000
Filtration 861,000
Granular Carbon Treatment 3,027,000
Adsorption $1,310,000
Regeneration 452,000
Building, control &
other equipment 1,265,000
Chlorination 361,000
Building & equipment $ 79,000
Contract basin 153,000
Generator 129,000
Sludge Treatment 1,688,000
Pump station $ 94,000
Thickener 47,000
Centrifuges 115,000
Furnace 565,000
Building, controls, piping,
electrical, & other equipment 867,000
Blending and Storage Reservoir 235,000
Maintenance Building and Lab 240,000
TOTAL CAPITAL COSTS = $10,924,000
Engineering 1,000,000
Design $ 530,000
Construction 470,000
$11,924,000
Note: Sitework, landscaping, electrical work and yard piping are charged to
the individual treatment operations according to their percentage of
total capital cost.
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TABLE 6 ESTIMATED ANNUAL COST OF OPERATION AND MAINTENANCE
WATER FACTORY 21
15 MGD WASTEWATER RECLAMATION FACILITIES
Salaries Cost $ 258,000
Maintenance Materials 40,000
Utilities
Electricity $473,000
Natural gas 71,750
Other 6,000
Subtotal $ 550,750
Chemicals
Lime $ 70,000
Chlorine 10,000
Activated Carbon 45,000
Alum & Polymers 55,000
Sodium Chloride 10,000
$ 190,000
Total Operations and Maintenance $1,038,750
TABLE 7 TOTAL COSTS
15 mgd Wastewater Reclamation Facilities
Orange County Water District
COST (c/thou. gal.)
Capital Oper. & Maint. Total
Influent pipeline & pump station 0.5 0.6 1.1
Clarification 1.1 2.4 3.5
Ammonia stripping 4.2 5.1 9.3
Recarbonation 0.6 1.1 1.7
Filtration 1.3 1.5 2.8
Carbon adsorption 4.5 3.7 8.2
Chlorination 0.5 1.0 1.5
Sludge treatment 2.5 4.6 6.1
Other 7.3 0.9 3.2
TOTAL 17.5 20.9 38.4
Note: Costs are based on the following assumptions:
1. Service life of facilities = 30 years;
2. Interest rate = 6%;
3. Facilities operate 330 days per year & produce 15 mgd.
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DISCUSSION
QUESTION: Mr. Franklin D. Dryden, Sani-
tation District of Los Angeles County,
Whittier, California. I want to ask if
you had had any concern about air pollution
problems from either your recalcination
or your ammonium stripping process. Is
there an APCD requirement you are meeting
in either of these regards?
RESPONSE: Mr. Cline. When we first got
the idea for the region from the Air Pol-
lution Control Board and put out our plans,
they gave us some rather stringent require-
ments on the off-gases from the furnaces.
We have some sophisticated scrubbing units
which we think are going to satisfy the
requirement. For the ammonia towers, we
have a five-fold safety factor—a dilution
of about five. Consequently, we don't get
any contamination from that source. We
do get a very light obtundent odor in
the morning.
COMMENT: Mr. Ongerth, California Depart-
ment of Health, Berkeley, California. I
think it would be helpful to clarify a
couple points for the record. The chloride
requirements, for example, are Water
Quality Control requirements, not State
Department of Health requirements, and
some others fall in that category as well.
The other point is that the District is
not in the clear with relation to domestic
use of water that is drawn from this re-
charged water. The State Board of Health,
in granting a permit for this operation,
placed a provision that the kinds of ques-
tions that are going to be discussed at
this conference had to be answered to in-
dicate that we were on the side of safety
before this water could be used in the
domestic wells.
I an constantly confronted with questions
around California from people who say,
"Isn't Orange County recharging and using
wastewater for domestic purposes?" And,
of course, they are not even in operation
yet. But beyond that, they will not be
permitted to have this water reach domestic
wells in ways that can be measured by the
parameters that we may have to deal with
in the future. I think it is important
that this be understood.
RESPONSE: Mr. Cline. You can see that
we are being monitored by the California
Department of Health. Of course, we in-
tend to cooperate. We don't have any
choice as far as that goes.
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WASTEWATER REUSE AS A WATER RESOURCE - THE DENVER EXPERIENCE
J. L. Ogilvie
Manager - Denver Water Department
144 West Colfax Avenue
Denver, Colorado 80202
ABSTRACT
Because of a unique water supply situation and after extensive planning, Denver and per-
haps other communities are seriously considering reuse as an alternative for supple-
menting future supply. However, the distance between serious consideration and imple-
mentation is quite large, and much remains to be done to close the gap.
Denver's present supply comes from conventional tributary sources, a very limited
groundwater supply, and extensive transmountain diversions. The potential of even this
latter source will be insufficient within the forseeable future. Potable reuse appears
to be the only major alternative to massive shortages.
Having performed the initial planning and research, it seems likely that reuse can be
safely accomplished and accepted by the public. It is obvious, however, that the most
difficult and costly research lies ahead. Water quality must be achieved. Adequate
treatment will be required to guarantee a fail-safe system. Pollutants must be
identified and removed. Ongoing studies will be required to guarantee safety prior to
implementation. Progress will have to be continually assessed. Costs will have to be
identified and compared with costs of treating conventional supplies.
One community cannot, and should not, solve these problems in isolation. We must
recognize that the differences between indirect reuse and direct potable reuse are
slight; that the former occurs today and that the latter will occur in the near future.
Only through a coordinated national effort will research have the needed credance and
yield answers in the few short years available.
Throughout the nation today --in the
press, by various scientific disciplines,
among environmentalists and in the water
utility industry -- there is an ongoing
dialogue about water pollution and how
to remove pollutants from water.
For years we have ignored the fact that
human and industrial wastes pollute our
natural water supplies in the first
instance and, secondly, to remove con-
taminants placed there through the use of
water by man.
When we discharge wastewater into a
stream or river and allow it to be
purified through the natural processes
and dilution before it it is withdrawn
for use again, we call it an indirect
reuse.
However, when we take that same waste-
water and route it directly through a
treating process and immediately rein-
troduce it to another point of use, we
say it is a direct reuse. It is this
latter process, which is attracting the
interest of municipal water utilities,
that I will discuss with you today. I
hope you will find the Denver experience,
which has been in the experimental stage
for several years and is on the planning
60
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board for implementation in the near
future, of interest.
At the onset, I wish to encourage every-
one in this field of water reuse not to
be discouraged by criticism of going too
slow. We are dealing with the health
and well being of all of our people when
we talk in terms of introducing a new
factor into our drinking water supply.
Therefore, it is absolutely mandatory
that we proceed cautiously.
We have been in the water purification
business a relatively short time,
actually just a little over 100 years.
Water purification by filtration dates
from 1870, when an English-type slow
sand filter was built at Poughkeepsie,
N.Y. A municipal filtration system for
bacterial purification of a water supply
didn't come along until 1893 when
Lawrence, Massachusetts completed a
2-3/4 acre bed and started filtering
water from the Merrimack River. In 1908,
in Jersey City, N.J., the water supply
was chemically treated with chlorine com-
pounds for drinking water -- another first.
Health problems caused by indirect
reuse --a city taking its water supply
from a river at a point below the sewage
outfall of another city -- are un-
fortunate. Adverse health effects by
direct reuse of water are intolerable
and unacceptable. The so-called "Magic
Mile of Stream" to purify and dilute
sewage, an old wives' tale, would have
you believe that a stream moving faster
than 2 mph purifies itself. There is
nothing magical about a stretch of slow
moving stream. It is aesthetically
pleasing, but whether or not the water
is being purified depends on many factors.
However, comparison is usually made that,
if there are dangers associated with
indirect reuse, then there must be
horrible consequences to direct reuse
where Nature has not been involved.
While not enough is known of the dangers
of indirect reuse, logic would indicate
that the more polluted the source, the
greater the chance for health hazards.
Any indirect reuse of water should be
accompanied with an ongoing program to
find out the extent of pollution and
methods of removing and/or treating
the problems.
There is another less obvious distinction
"between direct and indirect reuses. In-
direct reuse is an established practice.
Direct reuse has never been tried on a
large, continuing scale. Indirect reuse
has developed over a long period of time
through use of water treatment and
pollution control plants which treat water
as follows:
If it's sewage, secondary treatment.
If it's polluted surface water, co-
agulate it, settle it and filter it.
If it's pristine surface water, filter
it.
If it's well water, chlorinate it.
If it should be determined that Nature is
overloaded and health hazards do exist
with this established system, the solutions
will have to fit somewhere within the
existing patterns of use and treatment.
With direct reuse, it's a whole new ball-
game. New processes must be developed.
And the public must be conditioned to
accept the end product. No concrete has
been poured or pipes laid in the ground.
No plants have been built. No processes
tested over long periods of time. It is
not only possible but essential to answer
the questions of safety before major
facilities are built. What is required
is man-made treatment which consistently
does a better job than Nature in reducing
pollutant levels. Direct reuse can be
safer because the treatment, monitoring
and control of product will be much more
sophisticated. Reliability, redundancy,
and fail-safe methods will be stressed.
With an open awareness of the water source
and acknowledgement of the possible
dangers, planners, managers, and operators
will be able to effectively provide a safe
product.
The dangers of pollution in water sources
have long been known. As a general rule,
it has been assumed that selection of the
"best available source" and the application
of conventional treatment would guarantee
safety. This philosophy is being
questioned as identification techniques
improve and as medical science discovers
increasingly more obscure health effects
from trace amounts of various pollutants.
The concept of reuse evolved amid fears
and doubts. Shortly after the unsuccessful
1957 Chanute, Kansas experience, concerns
61
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were voiced over reuse-related health
effects. The concerns involved mainly
biological contaminants. And agencies
charged with protecting the public
health started taking a closer look at
possible dangers. A deluge of infor-
mation and misinformation has appeared
recently elaborating on the
possibilities of any of the known
chemical compounds being present in
sewage. One argument states that a
chemical could be undetectable and
resistant to treatment and this
mysterious "Agent X" could be concen-
trated through repeated reuse cycles
causing insidious damage to an unsus-
pecting population. Labels of "toxic,"
"carcinogenic," "mutagenic," and
"teratogenic," have been applied to this
infamous, unknown chemical.
These concerns cannot be dismissed
lightly. All of the possible dangers
of reuse must be considered in de-
signing a research program. Over-
reaction, however, and a fear of the un-
known must not be allowed to cause
abandonment of the reuse concept. The
potential benefits in water supply are
too great.
While some may challenge the concept of
producing safe drinking water from
sewage, most can envision a treatment
train which would guarantee an
acceptable product. Some might say
(and historically have said) that conven-
tional water and sewage treatment is
adequate. Others might demand ten unit
processes beyond distillation. The
proper course of action, I believe,
involves extensive and documented re-
search to determine the extent of the
dangers associated with direct reuse
and the remedies. In this process,
questions of cost, public acceptance,
reliability and aesthetics must also be
answered.
One of the most objective and enlight-
ened approaches to direct reuse has
been shown by the international group
of experts assembled in 1971 and again
last fall by the World Health
Organization. Their report concluded
that:
". . . Present-day technology is
adequate if proper conditions prevail
to treat most municipal wastewater to a
degree that will render them safe for
drinking and other domestic uses, by
careful management, the application of
appropriate treatment processes, and a
rigorous programme (sic) of sophisticated
surveillance, monitoring, and testing are
absolutely essential if the public health
is to be protected."
The report goes on to discuss the needed
research and controls associated with
such a program. The recommendations
include provision that:
(1) Water quality standards appropriated
to the reuse should be formulated and
rigidly enforced.
(2) Full knowledge should be maintained
of each water source, whether a natural
body of water or wastewater, so that
treatment may be adequately designed to
allow for possible fluctuations in quality,
account taken of potential health risks,
and adequate safeguards taken to ensure
the safety of workers and consumers.
(3) Laboratory facilities should be
adequate to undertake the program of
monitoring and testing appropriate to the
proposed water use.
(4) Research should be conducted into
the potential long-term health effects
of trace materials and residues remaining
after conventional water treatment.
Research on this topic should include
both physiological investigations on
individuals known to have been using
drinking water derived from polluted
sources and toxiocological studies on the
waters themselves under laboratory
conditions.
(5) Research should be conducted into
improved methods of identifying,
measuring, and monitoring chemical and
microbial pollutants. Rapid identifi-
cation of bacteria and viruses is
required, and there is a need for a
means of monitoring chemical pollutants
by simple field tests.
Recent articles in technical media have
concluded that these and other re-
search efforts are needed. Most of the'
emphasis has been placed on the identi-
fication and inactivation of viruses and
62
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on the effects and identification of
trace organic chemicals. In addition,
questions of process reliability and
public acceptance have also received
attention. Recent estimates by the
Environmental Protection Agency have
placed the research cost at $50 to $150
million dollars.
The Denver Water Department is embarked
on a direct reuse program. We have
been supplying water to the Denver
area for over half a century and
streams in the area contribute only
about 100,000 acre feet per year of
supply which is insufficient to meet
current continuing water needs. The
Department has developed extensive
transmountain diversions to augment this
supply and we are now delivering over
250,000 acre feet each year in the
Metropolitan area. Provision is made
in some of our water appropriations,
secured under Colorado Statues,for
effective use and reuse of our previous
water resource. Looking down the road
20 or 30 years we clearly see the time
when direct reuse must be the source of
continuing water supplies to meet
people's needs. Denver began in the
late 1960's to evaluate various methods
for utilizing its sewage effluent and
we are currently pursuing an aggressive
program of research development to give
us the capability of reusing our water
safely. The Department's priorities are
not with towing and melting icebergs or
with trans-continental pipelines, but
with a more realistic and viable source
in Denver's own backyard.
From the beginning of the successive use
program, public opinion has occupied a
prominent place in Denver's thinking.
No program can succeed without the
approval of an informed public. It is
obvious that all actions taken must be
suppored by local and national attitudes
which ultimately will be reflected in
law.
The Denver Water Department commissioned
an attitude and perception study in 1972
to test our citizens awareness of reuse.
Results indicated that 65% of Denver
residents were familiar with the reuse
program. Also, the more familiar a
person had been with the program, the
more likely he was to approve of it.
A question asked later in the survey,
after showing each subject a reuse infor-
mation card, produced a much higher
approval of reuse than a similar question
asked earlier. When the quantity of the
reuse water was defined as equal to
present supplies, acceptance jumped to
These results differ somewhat from
studies conducted elsewhere. The
differences may be attributable to the
attitude of the interviewers or to
Denver's extensive public information
program. The important point is,
though, that while a national public
information program would be helpful, it
is the attitude of Denver's citizens
that is important to Denver. Public in-
formation programs will be continued arid
will remain primarily local functions.
Equally important as public acceptance is
the necessity of meeting quality stan-
dards. The 1962 United States Public
Health Service Drinking Water Standards
list twenty chemical parameters, nine of
which serve as absolute grounds for
rejecting a supply as unsafe for human
consumption. The World Health Organiza-
tion Drinking Water Standards contain
only a few more. Neither of these widely
known and accepted standards lists more
than a few synthetic organic compounds
despite the fact that hundreds of such
chemicals may find their way into munici-
pal and industrial wastewater. The
existing standards do not exhaust the
list of potential inorganic toxicants
that may be found in industrial wastes.
Conventional drinking water standards
were originally based on the assumption
that water for human consumption would
generally be drawn from groundwater
sources or from protected, uncontaminated
surface water sources, and that the
limited number of chemical parameters_
included were adequate. This assumption
is rarely true for most surface supplies
of today.
The 1971 recommendations of EPA's
Technical Task Force on the Revision of
the Drinking Water Standards states in
part that, "the existing standards apply
to a water supply that has been obtained
from the most desirable source and are
not intended for application to wastewater
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effluents, used directly as a raw water
source." They were developed to be used
in conjunction with a sanitary survey
that would assure a relatively un-
polluted source.
In all probability, more stringent
standards will have to be developed for
recycled water. Little has been done to
date, however. Two alternatives are
open for an agency considering potable
reuse. One is to conduct in depth
toxicological and epidemiological studies
over a period of years to indicate any
health problems and provide background
criteria for workable standards. The
other alternative is to adequately
monitor wastewater and to remove the use
increment between the raw water and
sewage effluent. Thus the standards for
renovation to a potable supply would be
removal of the entire use increment.
With monitoring sophistication, this
would alleviate many questions concerning
possible deleterious effects.
The latter approach has been chosen by
the Denver Water Department and offers
side benefits of considerable merit.
First, "use increment removal" offers a
hedge against future standards. There is
no guessing at what standards might be
set and no worry that a new standards
might negate years of testing a process
train. Second, the idea of "as good or
better than what we're drinking" has a
tremendous public relations benefit.
Combining extensive analysis and "use
increment" removal with biological
(toxicological and epidemiological)
studies as a guarantee on safety gives an
enviable product -- it's not only safe,
but it's as good as mountain water.
Sewage is polluted water. This fact does
not take a great deal of verification.
No one would take a drink from a sanitary
sewer or bathe with secondary effluent.
And yet, every glass of water consumed
or bath taken from a metropolitan system
contains water which has previously
flushed a toilet. The difference, of
course, is a matter of degree, of time,
or proximity and, more importantly, of
treatment.
Since sewage is vastly more polluted than
most raw water sources, it is obvious
that a much greater potential exists for
health problems. The remedy, of course,
is to apply the right combination of
treatment -- natural and man-made --to
remove those contaminants posing a
threat. This is no more than the goal of
conventional water treatment, though
requiring more effort. This all seems
quite simple, but a problem arises in
trying to identify the contaminants which
pose a threat. With current technology
we are not able to detect pollutants
below certain concentrations and the
health dangers of every constitutent of
sewage are not known. Medical science
may never be satisfied with its knowledge
of such matters. For this reason the
only logical approach for the higher
order reuses is to remove everything
which could possibly be of concern. In
the case of potable reuse, this is use-
increment removal.
Denver's use-increment removal program
would depend heavily on treatment and
monitoring to duplicate present potable
water quality. This level has been
shown safe through years of use. Medical
health effect studies would assume a
secondary or fail-safe role. Toxicolog-
ical examination would have to accompany
the program as a safeguard though direct
reliance on the results would not be
necessary. Epidemilogic evaluation,
while needed nationally, would have little
direct bearing on such a program since
there would be no better quality water
with which to compare.
The practice of advanced wastewater
treatment has developed from rudimentary
beginnings to its current status as a
proven tool in man's fight against
pollution. As with any new technology,
the development of AW is continuing and
new advances will be made. The state of
the art is at such a point today, however,
that reliable processes can be linked to
produce whatever quality water is desired.
The higher the quality, the more the cost,
of course.
The only demonstrations to date of potable
reuse have either been accidents or have
had far different goals than those
presented here. The space industry
experience has involved only short-term
use and the South-West Africa experience
has evolved with less regulation and less
citizen involvement than expected
64
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in Denver. The Denver Water Department's
goals of absolute safety and reliability
combined with duplication of original
quality necessitate a plant-scale
demonstration prior to full scale
implementation. Economics dictate that
this plant be smaller than a 100 MGD
capacity of a full size plant. Balancing
all factors, we conclude a demonstration
plant of one MGD is the most desirable
size. This plant operating for a number
of years would yield design criteria for
up to 100 MGD of full size construction
and would produce the water needed for
extensive quality and health testing.
Data from a one MGD plant would allow
further future designs to maximize
reliability without spending money for
excess redundancy. Therefore, a
demonstration plant should be designed
with sufficient flexibility so that
optimums can be found. On the other
hand, there is no point in installing '
extra processes not anticipated to be
needed since resulting product water
data would be misleading. Instead, side
streams of less than one MGD would be
included to evaluate processes which
might eventually prove better than those
originally installed.
Denver's program of research involves
pilot plant operations, sponsored
research at the University of Colorado,
cooperation with EPA, use of nationally
known consultants, public information
programs and related functions such as
project direction and planning. Major
additional elements of the programs
include actual construction of a 1 MGD
demonstration plant producing potable
water. Extensive quality monitoring and
toxicological studies on the water will
be pursued for several years while the
product water is being used for non-
potable purposes.
In December, 1974, we assembled a panel
of advanced waste treatment experts in
Denver to advise the Department and its
consultants, on process of selection.
The consultants are presently conducting
a conceptual design study on the pro-
posed demonstration plant. The plant is
expected to be on-line in 1978 and will
operate as long as is necessary to
determine economic feasibility, absolute
safety and public acceptance of what
we are doing.
Denver's efforts toward direct potable
reuse are the results of circumstances
not uncommon in other areas. As a result,
the questions to be answered here will
contribute to the national knowledge of
pollution and water supplies, but will not
solve all the problems facing the
industry because our program will be
influenced by local conditions. Little or
no spinoff is expected in the area of
indirect reuse health effects, for
instance. In addition, it is inconceiv-
able to imagine that Denver, working alone,
can perfect monitoring techniques
adequate to guarantee safety in all other
areas.
In this new found era of environmental
enlightenment, the terminology of "space
ship earth" has been used many times to
help us relate to some of our global-
environmental crises. It is significant
to note that recycling water for direct
potable reuse was a primary goal of the
National Aeronautical Space Administration.
I submit that direct potable reuse should
be a primary goal of the World Health
Organization and the U. S. Environmental
Protection Agency.
In summary, then, to achieve this goal it
seems to me our priorities should be:
1. Recognition and acknowledgement of the
need for a national research program on
direct potable water reuse.
2. Directing a major part of this nation-
al research to health questions to deter-
mine if direct and indirect reuse of
water has any possible detrimental effects
on users.
3. Establishing a significant budget to
carry on this program to assure reliabil-
ity and public acceptance.
4. Developing improved laboratory
analytical equipment and procedures
capable of measuring trace amounts of
contaminants and rapid identification of
bacterial and virus particles.
Provisions in the 1974 Safe Drinking Act
address this need. Sections in the Act
provide research monies in the reclamation
field. But the water industry must
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continue to challenge federal and state
agencies to provide sufficient funds so
that these objectives can be achieved.
Simply put, money right now is the
name of the game. And the current
federal budget of $400,000 is grossly
inadequate. It should be in the range
of $5 to $10 million annually. Only
through substantial and coordinated
total efforts, will our reuse research
endeavors of the 70's and 80's yield
the answers to assist in the solution
of present and future water resources
problems.
DISCUSSION
QUESTION: Mr. Ongerth, California
Department of Health, Berkeley, Califor-
nia. What is your prediction of when
Denver might be starting with the final
reuse?
RESPONSE: Mr. Ogilvie. Well, as we
see it now, we are going to have to
move to the direct reuse of water by the
1980's or early 1990's. That is quite
a ways down the road, but when you con-
sider the research, and the fail/safe
procedures that have to be established,
it will go very rapidly.
QUESTION: Mr. Ongerth, California
Department of Health, Berkeley, Califor-
nia. Then this is your prediction of
when Denver will be making direct potable
reuse?
RESPONSE: Mr. Ogilvie. Yes, sir.
QUESTION: Mr. Gallowin, National
Bureau of Standards, Washington, D.C.
Can you give us an indication of pro-
jected costs involved in direct reuse?
RESPONSE: Mr. Ogilvie. Yes. Our re-
use program will be directed toward tak-
ing those waters which we can recycle,
those we actually own and which we could
use as many times as possible, and pro-
ducing this potable grade water. Then
we will initiate a program of recycling
it and diluting it into our normal water
supply such that no particular area of
the city will initially have one hundred
percent of the reprocessed or reuse water.
Down the road in later years, when reuse
is more of an accepted pattern, this nay
not be necessary. But under the circum-
stances, we think it will have to be di-
luted back into our present system.
QUESTION: Mr. Gallowin, National
Bureau of Standards, Washington, D.C.
At what cost? Are we speaking of fifty
cents per thousand gallons or ten dollars
per thousand gallons?
RESPONSE: Mr. Ogilvie. I think our
costs will run in the neighborhood of
maybe seventy-five cents per thousand
gallons.
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WASTEWATER TREATMENT TECHNOLOGY FOR POTABLE REUSE*
R. B. Dean and J. J. Convery
Science Advisor and Director
Advanced Waste Treatment Research Laboratory
Environmental Protection Agency
Cincinnati, Ohio 45268
ABSTRACT
Technologies are available today to produce reusable water of potable quality from
municipal wastewater. The choice of a system depends on the quality and quantity of
available dilution water, facilities available for disposal of waste products, and the
scale of the operation. Long-term, reliable operation of waste treatment plants producing
water for reuse has been demonstrated in situations where there is a need for the water or
where strong regulations control discharge parameters. Leading unit operations are dis-
cussed in terms of their capability to reliably remove specific pollutants. Adjuncts
that will improve reliability include instrumentation, surge capacity, and provision for
disposal or reprocessing of substandard product. Specific case studies illustrating
performance are presented.
INTRODUCTION
Wastewater treatment technology can
potentially produce a renovated effluent
that meets all objective drinking water
standards. Health effects research aimed
at revising current standards or developing
new ones should apply to all water sources
and should not differentiate between tra-
ditional supplies and renovated effluents.
The preceding statements are intended to
stimulate discussion and should be consid-
ered by all of the workshops at this con-
ference on reuse.
The treatment received by municipal
wastewater before its reuse as part of a
potable water source has varied from mini-
mal primary treatment, or even less, to the
sophisticated chain of treatment at
Windhoek, where a dilution ratio of less
than six parts of surface water to one part
of reclaimed wastewater has been used (1).
All potable reuse systems employed to date
have had two aspects in common: time and
dilution. The more time and the more
For presentation at the Municipal Waste-
Water Reuse Research Needs Workshop,
Boulder, Colorado; March 18, 1975.
dilution that is available, the less treat-
ment has been deemed necessary before a
municipal effluent is reused as a potable
water supply.
So much for history. Primary treat-
ment is no longer sufficient for discharge,
even to rivers that are not used as a
drinking water source, and there is some
new evidence that conventional water treat-
ment may not be removing enough pollutants
from some supplies (2). Better water and
wastewater treatment technology will be
required as our knowledge of the occurrence
and effect of specific contaminants
increases. The purpose of this paper is to
review the specific capabilities of current
wastewater treatment technology.
STANDARDS TO BE MET
The new standards for potable water
have not yet been published by the EPA.
There are several sets of standards and
recommendations in the literature. These
include the Public Health Service Drinking
Water Standards of 1962 (3), the WHO
67
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recommendations of 1964 (4), the AWWA goals
of 1966 (5), the Green Book of 1968 (6),
and the Blue Book recommendations of 1972
(7). For public drinking water supplies,
the Blue Book recommendations by the
Committee on Water Quality Criteria of the
National Academy of Sciences, National
Academy of Engineering, probably represent
the best published approximation to forth-
coming standards. These recommendations
are for raw water quality for public
supplies and are intended to assure that
the water will be potable - for surface
water with defined treatment; (flocculation,
sedimentation, rapid sand filtration, and
disinfection)- and for groundwater with no
treatment. The recommendations already
incorporate substantial factors of safety.
Table 1 compares Blue Book recommenda-
tions for very toxic elements with the
average product water from advanced waste
treatment pilot plants at Dallas (8) for 8
months and Denver (9) for 8 months. In
both plants, biological treatment was
followed by lime precipitation to a pH
greater than 11. The clarified water was
filtered and passed through granular acti-
vated carbon. Table 2 makes the same com-
parison for less toxic elements; some of
them are limited because they cause taste
or color problems in water supplies. Table
3 lists limits for selected organic
TABLE 1. VERY TOXIC ELEMENTS mg/1
Mercury
Cadmium
Selenium
Chromium
Lead
Std.
.002
.01
.01
.05
.05
PL
.0001
.008
.001
.009
.045
DN
.002
-
.006
.027
TABLE 2. LIMITED ELEMENTS mg/1
Manganese
Arsenic
Iron
Barium
Copper
Zinc
ltd.
0.05
0.1
0.3
1.0
1.0
5.0
DL
.006
.007
.05
.10
.04
.03
DN
.05
-
.16
-
.08
.13
compounds in micrograms per liter and com-
pares them with concentrations in the
Dallas effluent (10). Only a few of the
pesticides tabulated in the Blue Book are
listed. Robeck, et al.,(ll) showed that
activated carbon columns were effective for
removing pesticides even when taste and
odor broke through. The more toxic pesti-
cides are being limited to authorized
applicators for special situations, and
their concentration in the environment
should be decreasing. In general, the re-
commended levels are less than a fifth of
the level considered safe by the Blue Book
committee.
The nonspecific parameters, MBAS and
CCE, are compared with South Lake Tahoe
(12) and Pomona (13) effluents. Tahoe used
a scheme similar to that of Dallas and
Denver; Pomona fed unfiltered activated
sludge effluent directly to the carbon
columns for a 4-year period. Table 4 com-
pares salts and nutrients with the effluents
of the Central Contra Costa Sanitary
District (CCCSD) ATTF plant (14). This
plant treated 1.5 mgd (6000 m^/day) of resi-
dential wastewater with lime, followed by
biological nitrification and denitrifi-
cation in a 3-month pilot study for a plant
to reclaim water for industrial use.
TABLE 3. .ORGANICS yg/1
Aldrin
DDT-Total
Diazinon
2, 4-D-Total
MBAS
CCE
Std.
1.0
50
100
20
500
300
DL
.007
>.006
> . 003
.1
150 (T)
26 (P)
TABLE 4. SALTS AND NUTRIENTS mg/1
Std.
CC
Chloride
Sulfate
Phosphate
Ammonia N
Nitrate N
250
250
-
0.5
10.0
-
-
1.0
0.4
0.8
References: Std, Blue Book (7); DL, Dallas metals (8), pesticides (10), CC, CCCSD (14),
DN, Denver (9), T, Tahoe (12), P, Pomona (13).
68
-------
Based on available information, there
will be little difficulty in meeting the
published recommendations by applying
proven advanced waste treatment technology
to municipal wastewater. However, source
control may be required to prohibit excess-
ive industrial discharges of highly toxic
wastes such as mercury, selenium, and some
pesticides. In general, biological treat-
ment, chemical precipitation, and carbon
adsorption can remove the listed contami-
nants, with the exception of salts.
Dilution with water of low TDS, either from
fresh-water supplies or desalted brackish
water, is currently the most economical
way to keep salts within limits.
TECHNOLOGY FOR RELIABILITY
Reliability, like any other aspect of
treatment, costs money. One can expect
only as much reliability as is required or
paid for. The Community Water Supply Study
of 1969 (15) showed that the reliability
of plants increased from 76% in small
plants to 100% in the largest plants, as
measured by the percent that met mandatory
limits. However, the percent that met
recommended limits was almost independent
of plant size and averaged only 75%.
Obviously, a large plant is better equipped
than a small plant and can more easily meet
requirements, but even the largest plants
had no incentive to meet recommendations.
When a monetary value is set on the
product water for reuse, then reliability
can become very good. Whittier Narrows in
the Los Angeles County Sanitation Districts
has sold more water for indirect potable
reuse than any other plant. The water is
sold at the same price as Colorado River
water and is used with the river water to
recharge undergound aquifers (16). This
activated sludge plant has operated from
1962 through 1974 without interruption
from internal causes, but it has been shut
down once or twice because of industrial
toxicants or flood waters. The plant has
paid off its construction costs out of net
operating revenues in less than half of the
projected time. The high level of perfor-
mance owes much to the dedication of the
operating management, but it is certainly
reinforced by the fact that the plant loses
money whenever it is not meeting specifi-
cations. Figures 1, 2, and 3, based on
data supplied by John D. Parkhurst (17),
show the fraction of the time in 1974 that
50
20-
5--
2--
REQUIREMENT
WHITTIER NARROWS
SUSPENDED SOLIDS
1%
10%
50%
90%
99%
Figure 1. Suspended Solids at Whittier
Narrows Effluent
0.2-
0.1-'
.05--
0.02"
0.01
RAW
WHITTIER NARROWS
LEAD
REQUIREMENT
SECONDARY
1%
10%
50%
90%
99%
Figure 2. Lead in Raw and Secondary
Effluent at Whittier Narrows
O.05
0.02- •
o 0.01
0.005- •
O.OO2- -
WHITTIER NARROWS
CADMIUM
SECONDARY
1%
10%
50%
90%
99%
Figure 3. Cadmium in Raw & Secondary
s Effluent at Whittier Narrc
arrows
69
-------
each parameter was less than the plotted
value for cadmium, lead, and suspended
solids. Concentrations of the unfiltered
effluent are shown on a logarithmic scale.
The California Drinking Water Requirements
are shown for the metals, and the EPA
secondary treatment requirement for the
suspended solids.
In the case of South Lake Tahoe (12),
the District is prohibited from discharging
any wastes in the Basin and must meet
strict requirements for export to its own
reservoir in the adjacent drainage basin.
Figures 4, 5, and 6 show the fraction of
days the selected parameters were less than
the values shown for turbidity, COD, and
coliform. These data cover the period from
September 1968 to December 1974 and are
based on monthly reports showing daily per-
formance for over 2,000 days. Suspended
solids were uniformly below detectable
limits (1.0 mg/1). Requirements for export
are shown as stepped lines passing through
the points specified by the Lahontan
Regional Water Quality Control Board.
The overall reliability is unprece-
dented in waste or water treatment plants
and would be considered excellent in the
chemical industry for a factory having the
same capital cost. The total cost of
operation, adjusted to operation at design
capacity, is approximately twice the cost
of operation of a conventional secondary
treatment plant that is required to deliver
only 30 mg/1 BOD, 30 mg/1 SS, and 200 MPN
water with no limits on phosphates, MBAS,
or COD (18). Examination of the raw data
suggests that the plant quality has crept
closer to the required limits as the years
have gone by.
One of the reasons for the excellent
reliability of the Tahoe plant is the avail-
ability of large storage volumes that can
be used to equalize flow and reprocess any
substandard product. When a manhole cover
near a creek bottom was pulled off in
December 1973, flood waters delivered more
than twice the design flow for 2 days. An
excess 24 million gallons (100,000 m3),
which is more than 3 times the daily design
flow, was sto'red and worked off over a
whole oionth without exceeding the required
limjLts at any time.
10%
50%
90%
99%
Figure 4. Turbidity in Tahoe Effluent
1% 10% 50% 90% 99%
Figure 5. COD in Tahoe Effluent
100
0.01
1% 10% 50% 90% 99%
Figure 6. Coliforms in Tahoe Effluent
70
-------
An alternative to storage is provision
to bypass substandard water to a disposal
site. At Whittier Narrows, wastewater is
drawn from a large trunk sewer and sludge
is returned to the same sewer along with
any effluent that might not meet specifi-
cations. Because treatment is expensive,
specifications are carefully met, and very
little treated water is wasted.
In addition to the aforementioned
facilities that will promote reliable
operation (namely storage or bypass capa-
city and the support functions of economic
incentive, enforced legal restraints and
dedicated personnel), there are a number of
engineering design features that will im-
prove reliability. The EPA has recently
published a Technical Bulletin on design
criteria for component reliability (19)
which is described in a recent article (20).
The new criteria would have prevented or
mitigated 91% of historical failures in 21
plants studied. The cost increase to meet
the new criteria is estimated to be from
1 to 7% of new construction costs. Con-
sistent application of reliability design
features, not only in the components listed
in the bulletin but also in the biological
and chemical processes used, will substan-
tially improve the admittedly unsatis-
factory operation of many municipal waste-
water treatment plants in the past. A com-
bination of good design and strong incen-
tive can supply the required degree of
reliability for reuse purposes.
In the following section, various unit
processes will be examined from the point
of view of performance and reliability,
since without reliability, potable reuse
becomes unthinkable.
UNIT OPERATIONS AND SYSTEM OPTIONS
Several single-step phase change puri-
fication processes, including distillation,
freezing, and solvent extraction, have been
suggested for wastewater treatment.
Despite the apparent simplicity of a single
process that would separate pure water from
all pollutants, it has proven to be less
expensive and more reliable to employ a
series of processes, each designed to
remove one or more categories of pollutants.
Each process can be adjusted to the pecul-
iarities of the wastewater, and the series
can provide multiple barriers to biological
pollutants such as viruses. Limited full-
scale experience is currently available on
the performance of complete wastewater ren-
ovation systems specifically designed to
produce potable quality water. However,
abundant information is available on the
performance, cost, and reliability of candi-
date processes that could be incorporated
into wastewater renovation systems.
Unit Operations
Systems that are suitable for utili-
zation in wastewater renovation systems
include biological or chemical oxidation,
chemical precipitation, sedimentation,
filtration, adsorption, and disinfection.
The choice of process and the order in
which the processes are used varies, and
any one of them may be employed more than
once in the treatment sequence.
Primary sedimentation is the lowest
cost process for removing the bulk of the
solid pollutants in wastewater. A primary
clarifier can reduce the cost of subsequent
biological treatment and is cost effective
in larger plants. Chemical precipitation
with lime, iron salts, or alum in the pri-
may can further reduce the load on the bio-
logical system. Lime treatment to a high
pH removes most of the phosphates and more
than half of all other major pollutants,
including soluble TOC and prepares the
effluent for reliable biological treatment.
Lime clarification followed by biological
nitrification was chosen at CC6SD (14) as
the lowest cost way to meet local require-
ments for reuse or discharge to San
Francisco Bay. Other studies have shown
significant removals of pathogens (21) and
heavy metals (22, 23) when the primary tank
is limed to a pH of 11 or more. Lime treat-
ment is easy to control by pH; the volume-
tric dosage is proportional to flow but is
relatively independent of fluctuations in
water quality entering the plant. The
sludge produced can be processed for dis-
posal or reuse without digestion (24).
Aerobic biological treatment in sus-
pended growth reactors (activated sludge,
aerated lagoons) or fixed film reactors
(trickling filters, rotating biological
disks) is the lowest cost method for
removing most small soluble organic mole-
cules. Biological processes can also be
used to oxidize ammonia to nitrates (25,26)
as well as to reduce the nitrate to nitrogen
gas. A well-managed biological plant is
71
-------
capable of handling normal diurnal fluc-
tuations in load but is limited hydrauli-
cally by the capacity of the clarifiers.
Modifications have been developed that per-
mit biological treatment to adjust to very
wide fluctuations in load, provided that
the fluctuations are recognized as they
enter the plant (27). Instrumental sensing
and control of dissolved oxygen in acti-
vated sludge can reduce aeration costs and
increase performance (28).
Tertiary treatment with chemicals is
even more effective than primary floccu-
lation and forms the basis for most AWT
systems designed to produce reusable water
(Tahoe, Dallas, Boulder). For maximum per-
formance, it is necessary to filter the
clarified effluent in a multi-media filter,
using an appropriate flocculant to remove
colloidal precipitates. At Ely, Minnesota
almost complete removal of phosphates is
necessary to protect Shagawa Lake from
excessive algal growth (29). The Ely
plant uses an existing trickling filter
plant, which is followed by two-stage lime
clarification at pH 12 and 9.6, respective-
ly, addition of ferric chloride and sul-
furic acid to pH 7.5, and multi-media
filtration with supplemental alum feed and
chlorination. From March 1973 through
August 1974, the monthly averages of total
phosphate in the effluent varied between
0.021 mg/1 and 0.077 mg/1, with an average
of 0.043 mg/1. This demonstration project
has shown that an exceptional quality
product can be produced by providing ter-
tiary treatment to an existing facility
that is grossly overloaded.
Adsorption on carbon is a reliable
process for removing nonpolar and surface-
active organic molecules from solution (30).
Regeneration at about 950°C destroys all
the adsorbed organics, converting some of
them to more activated carbon. Bacteria
growing on partly exhausted static carbon
beds appear to liberate substances such as
amino acids, which are difficult to retain
on carbon. New operating techniques may
have to be developed if it is demonstrated
that the leakage of this organic matter
significantly degrades water quality. The
substances produced by bacterial action on
carbon that is used to treat water supplies
will be similar to those produced in the
treatment of wastewater. When limits are
set for organic matter in drinking water,
it will be possible to decide on the
advanced waste treatment system that will
meet these standards. Present limits are
based on extracts of test carbon columns,
CCE, and may have little toxic signifi-
cance (31). !
The stepwise removal of metals by
chemical precipitation, filtration, and
adsorption on carbon has been followed by
Murayama,et al., (23) in a physical-chemical
system using lime or iron salts as floccu-
lants. In such a system, there is sub-
stantial removal of organic matter by
bacterial action in the carbon columns. In
these pilot plant studies, each successive
step in the system removed a significant
part of the toxic metals. Cadmium was
removed principally by chemical precipi-
tation and settling, with filtration and
carbon adsorption each contributing only a
small additional removal. Chromium,
however, was poorly precipitated by iron
salts or lime, but reduction on the carbon
column and precipitation as the trivalent
hydroxide increased the overall removals up
to
Disinfection is a necessary final step
in any water reuse system. Adequate disin-
fection requires previous removal of all
suspended'matter, whether the source be
river water or municipal effluent (32).
Violation of the turbidity standard alone
should be justification for rejecting
recycled water from any source, no matter
what method is used for disinfection. The
AWWA goal is 0.1 Jackson Turbidity Units
(JTU) (5). The possible formation of chlor-
inated organics when water containing
organic matter is chlorinated (33) suggests
that chlorination should be used only as a
last step, after the water has been freed
from dissolved and suspended organic matter:
Removal of turbidity and soluble organic
matter is also desirable and perhaps manda-
tory before final disinfection with any
other agent such as ozone or ultraviolet
light. To reduce the chance of pathogens
being discharged through the treatment
system, lime clarification should be con-"
sidered. Lime clarification in the primary
is an alternate to prechlorination. Though
lime does not sterilize water, it does sig-
nificantly reduce both pathogens and indi-
cator organisms (21). White (34) has
pointed out that a given chlorine treatment
reduces the bacterial count by a calculable
factor, for example, 3,000^fold. If the
previous treatment has reduced bacterial
72
-------
counts below 3,000, then terminal disin-
fection will reliably destroy the remaining
organisms. There is no evidence that water
that is free from turbidity and has re-
tained a free chlorine residual of 1 mg/1
for at least one hour can contain infective
viruses or enteric bacteria. All the
available evidence indicates that such
water will be biologically safe regardless
of whether it came from a wastewater plant,
a polluted river, or a protected water
source. A fail-safe procedure would be to
hold the water in batches for one hour and
monitor free chlorine, turbidity, and
organic matter before releasing each batch.
Water that failed to meet specifications
would be reprocessed. Automatic instru-
ments are available for all of the suggest-
ed quality assurance tests.
Nitrogen in the form of ammonia must
be reduced below 0.5 mg/1 to meet drinking
water standards. If nitrogen compounds are
present as nitrates, up to 10 mg/1 N is
acceptable. Biologically treated waste-
water usually contains less than 20 mg/1 of
N, either as ammonia or as nitrate. Con-
version of nitrogen from ammonia to nitrate
is a biological process that is well under-
stood (25, 26). Nitrates can be converted
to nitrogen gas by further biological treat-
ment when it is necessary to meet effluent
requirements as at CCCSD (14). If 50%
dilution water is available, nitrogen can
be most economically controlled by conver-
sion to nitrates with destruction of
ammonia residues by breakpoint chlorination
(26). Removal of all nitrogen by break-
point chlorination is probably unsuitable
because it results in as much as 200 mg/1
of additional chloride and over 300 ppm of
additional TDS in the product water.
Ammonia can also be removed by air strip-
ping in warm climates (35) or by adsorption
on selective ion exchange minerals (36), as
is being proposed at Occoquan.
Organic matter is removable by a com-
bination of biological oxidation, floccu-
lation, and adsorption. Traces of low-
molecular-weight compounds, including some
chlorinated hydrocarbons, may not be cap-
tured by any of these processes. Their
presence in surface water supplies has very
recently been documented (33), but their
toxicological significance is, at present,
unknown. Removal methods applicable to
water and wastewater treatment plants will
have to be developed.
In many situations, desalting of waste-
water will not be necessary. If the makeup
or dilution water supply has a TDS of less
than 150 mg/1 and the normal municipal in-
crement is 350 mg/1, then half of the water
supply can be reused effluent at 850 mg/1
without exceeding the PHS limits of 500 mgA
in the blend. If the makeup water supply
has a higher TDS, or if more than 50% reuse
is necessary, then it may be more effective
to desalt the makeup water rather than the
recycled water. This is the method chosen
by Orange County. The makeup water will be
distilled sea water (35).
Distillation has been considered as a
complete process for purifying wastewater
using essentially the same equipment that
is used to desalt sea water. However, dis-
tillation is a very poor method to separate
volatile pollutants such as ammonia and
numerous organic compounds from water (37).
Furthermore, scale and baked-on organic
residues will quickly foul heat-exchange
surfaces. Cost estimates have repeatedly
shown that advanced waste treatment systems
for removing nutrients and organic matter
are less expensive than distillation. Dis-
tillation, however, is currently being
studied to remove all the inorganic matter
(represented as TDS) from water. In fact,
distilled water should have some salts
returned before it will be acceptable to
most water utilities.
Other desalting processes include
reverse osmosis and electrodialysis. Mem-
branes used in these processes are easily
fouled by the components of wastewater so
that extensive pretreatment will be required.
At present, reverse osmosis is being con-
sidered for small mobile wastewater recla-
mation systems (38). Removal of dissolved
salts from water by any method is an expen-
sive operation that is complicated by the
fact that the salts that have been removed
must be disposed of as a brine. Disposal
to the open ocean is the only low-cost
method (39). Natural solar evaporation is
the next choice, but it is possible only in
arid areas (40).
CONCLUSIONS
1. Wastewater treatment performance
data is not available for all of the para-
meters included in existing drinking water
standards.
73
-------
2. Information that is available
indicates that wastewater treatment tech-
nology is capable of meeting all the stand-
ards that have been measured.
3. Full-scale wastewater treatment
facilities can be operated reliably over
long periods of time.
4. Long-term reliability testing of
a full-scale facility specifically designed
to produce potable quality water is needed.
References
1. Nupen, E. M., "Health Aspects of
Reusing Water for Potable Purposes-
South African Experience," This
Workshop (1975).
2. Eidsness, F., "Organic Contaminants in
Drinking Water," Willing Water (AWWA)
18 (12) (December 1974)
3. Public Health Service, "Drinking Water
Standards," PHS Publication #956 (1962).
4. Cox, C. R., "Operation and Control of
Water Treatment Processes," World
Health Organization; Geneva,
Switzerland (1964).
5. American Water Works Association,
"Water Quality Goals for Potable Water,"
60 (12) 1317 (1968).
6. National Technical Advisory Committee
to the Secretary of the Interior,
"Report of the Committee on Water
Quality Criteria," (Green Book), D. S.
Dept. of the Interior (1968).
7. National Academy of Sciences, National
Academy of Engineering, Committee on
Water Quality Control "Water Quality
Criteria 1972," (Blue Book) EPA
R-3-73-033 (March 1973).
8. Esmond, S. F., and Petrasek, A. C.,
Jr., "Trace Metal Removal," Industrial
Water Eng., 14-17 (May-June 1974).
9. Linstedt, K. D., and Bennett, E. R.,
"Evaluation of Treatment for Urban
Reuse," EPA R-2-73-122 (1973).
10. Saleh, F., and Wolf, H. W., "Pesticide
Removal at Dallas Water Reclamation
Research Center," in preparation (1975).
11. Robeck. G. G.,et al., "Effectiveness
of Water Treatment Processes in
Pesticide Removal," AWWA, 57. (2) 181
(1965).
12. Culp, R. L., et al., "Advanced Waste
Water Treatment as Practiced at South
Tahoe," EPA WQ 017010 ELQ 08/71
(NTIS PB 204,525) (1971).
13. English, J. N., et al., "Removal of
Qrganics from Wastewater by Activated
Carbon," Chem. Engr. Prog. Symp. Series
"Water 1970," £7 (107) 147 (1970).
14. Horstkotte, G. A., et al., "Full Scale
Testing of a Water Reclamation System,"
Jour. Water Poll. Control Fed., 46_ (1)
181 (1974).
15. Public Health Service, "Community Water
Supply Study," PHS, Dept. HEW,
(July 1970).
16. Parkhurst, J. C., "Water Reclamation at
Whittier Narrows, California," Water
and Wastes Engr., 38. (November 1968).
17. Dean, R. B., and Woods, H., "Reliability
of Tahoe and Whittier Narrows Water
Reclamation Plants," In preparation
(1975).
18. Evans, D. R., and Wilson, J. C., "Actual
Capital and Operating Costs for Advanced
Waste Treatment," Jour. Water Poll.
Control Fed., 44 (1) 1 (1972).
19. EPA Office of Water Programs Operation,
"Design Criteria for Mechanical,
Electric, and Fluid System and Component
Reliability," EPA 430-99-74-01.
20. Partridge, M. J., and Sutfin, C. H.,
"Designing Sewage Treatment Plants for
Reliability," Civil Engineering, ASCE,
M (January 1975).
21. Grabow, W. 0. K., et al., "The
Bactericidal Effect of Lime Floccu-
lation ," Water Research, .3, 943,
(1969)-
74
-------
22. Argo, D. G., and Gulp, G. L., "Heavy
Metal Removal in Wastewater Treatment
Processes. Part II, Pilot Plant
Operation," Water and Sewage Works,
7.5, (September 1972).
*
23. Maruyama, T., et al., "Removal of
Metals by Physical & Chemical Treat-
ment Processes," Presented to WPCF
Annual Conference (1972).
24. Dean, R. B., and Smith, J. E., Jr.,
"Disposal and Recycling of Wastewater
Sludges Containing Lime," 3rd Inter.
Lime Conf., Berlin, Germany (May 1974).
25. Earth, E. F., et al., "Chemical Biolog-
ical Control of Nitrogen & Phosphorus
in Wastewater Effluent," Jour. Water
Poll. Control Fed., 40 (12) 2040,
(1968).
26. Ehreth, D. J., and Earth, E. F.,
"Control of Nitrogen in Wastewater
Effluents," EPA Office of Technology
Transfer Design Seminar Program (1974).
27. Joyce, R. J., et al., "How to Optimize
an Activated Sludge Plant," Water and
Sewage Works, 96, (October 1974).
28. Roesler, J. F., "Plant Performance
Using Dissolved Oxygen Control," Jour.
Env. Engr. Div., Proc. ASCE, 100 EE5,
1069 (1974).
29. Wilcox-, R. L., "Removing in excess of
99% Phosphorous at Ely, Minnesota,"
"Water 1973," AIChE Symposium Series
#136, 70, 358-66.
30. EPA Technology Transfer, "Process
Design Manual for Carbon Adsorption,'1
Washington, D. C. (October 1973).
31. Carswell, J. K., et al., "Removing
Organic Matter from Drinking Water-
Monitoring Treatment Processes," News
of Environmental Research in Cincinnati,
EPA (December 1973).
32. Hudson, J. E., Jr., "High Quality Water
Production and Viral Disease," Jour.
AWWA, _54_ (10) 1265 (1962).
33. Bellar, T. A., et al., "The Occurrence
of Organohalides in Chlorinated
Waters," EPA 670/4-74-008 (1974)
34. White, G. C., "Disinfecting Wastewater
with Chlorination-Dechlorination,"
Water and Sewage Works, Aug. 70,
Sept. 93, Oct. 100 (1974).
35. Cline, N. M., "Wastewater Reuse in
Ground Water Management-Orange County
Experience," This Workshop (1975).
36. Kepple, L. G., "Ammonia Removal and
Recovery Becomes Feasible," Water and
Sewage Works, 121 (4) 41, 42, 62,(1974).
37. O'Connor, B., et al., "Laboratory
Distillation of Municipal Waste
Effluents," Jour. Water Poll. Control
Fed., 39 (10) R25 (1967).
38. Reuter, L. H., "Medical Unit, Self-
Contained Transportable (MUST) Program
of the U. S. Army Medical R&D Command,"
Unpublished (1975).
39. Dean, R. B., "Ultimate Disposal of
Wastewater Concentrates to the Environ-
ment," Env. Sci. & Tech., 2^ (12) 1079,
(1968).
40. Burns & Roe, Inc., "Disposal of Brines
Produced in Renovatiop of Municipal
Wastewater," FWQA 17070 DLY-05/70
(NTIS No. PB 197,597) (1970).
DISCUSSION
QUESTION: Ms. Hend Gorchev, EPA, Wash-
ington, D.C. John, have you measured the
influent concentration for carbon-
chloroform extracts of any of the organics?
RESPONSE: Mr. Convery.
directly comparable data
carbon treatment because
effluent is not filtered
to the carbon columns at
apparatus would not work
wastewater.
We do not have
on CCE before
the secondary
before being fed
Pomona. The CCE
on unfiltered
QUESTION: Mr. Gorden G. Robeck, Water
Supply Research Laboratory, Cincinnati,
Ohio. I find it very difficult, John, to
read that. Is that a point Hend? That 26
didn't show. Is that what is making you
wonder on the CCE?
RESPONSE: Msi Hend Gorchev, EPA, Wash-
ington, D.C. Yes.
75
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RESPONSE: Mr. Robeck. Water Supply
Research Laboratory, Cincinnati, Ohio.
That seems highly unlikely with a COD level
of ten.
RESPONSE: Mr. English, EPA, Cincinnati,
Ohio. I was responsible for those data
and they are accurate. They have been
published in a paper that I wrote in co-
operation with Frank Dryden from L.A.
County Sanitation District. (Reference
13).
RESPONSE: Mr. Robeck, Water Supply
Research Laboratory, Cincinnati, Ohio.
Well, we are going to have to tell the
waterworks people that they can go ahead
and put carbon in there.
RESPONSE: Mr. English, EPA, Cincinnati,
Ohio. That's probably an average.
RESPONSE: Mr. Convery. It's an average
value.
RESPONSE: Mr. English, EPA, Cincinnati,
Ohio. I've got a group of those same
levels that you are welcome to look at.
QUESTION: Mr. Robeck, Water Supply
Research Laboratory, Cincinnati, Ohio.
Average for three weeks or three months?
RESPONSE: Mr. Convery. Four years.
RESPONSE: Mr. English, EPA, Cincinnati,
Ohio. And we actually took those samples
just prior to regenerating the carbon. We
could have cheated and taken those when
we put a fresh batch of carbon in. But
we took those just prior to taking off one
of those carbon batches.
QUESTION: Mr. Robeck, Water Supply
Research Laboratory, Cincinnati, Ohio.
What is the cycle then for regenerating?
RESPONSE: Mr. Convery. It was at a
COD breakthrough of 14 or 10.
RESPONSE: Mr. English, EPA, Cincinnati,
Ohio. A COD breakthrough of 12. This is
total COD. We averaged about 8 to 10 over
the run.
QUESTION: Mr. Robeck, Water Supply
Research Laboratory, Cincinnati, Ohio.
So the cycle varies. What you are saying
is that you are not going to give me a
figure.
QUESTION: Mr. English, EPA, Cincinnati,
Ohio. What do you mean? Do you mean as
far as days of operation?
RESPONSE: Mr. Robeck, Water Supply
Research Laboartory, Cincinnati, Ohio.
Yes.
RESPONSE: Mr. English, EPA, Cincinnati,
Ohio. About seventy-five days. We had
to regenerate about twenty-five percent
of the carbon every seventy-five days, and
we measured the carbon-chloroform extract
at the end of that seventy-five-day cycle.
QUESTION: Mr. Robeck, Water Supply
Research Laboratory, Cincinnati, Ohio.
What method were you using for measuring
the CCE?
RESPONSE: Mr. English, EPA, Cincinnati,
Ohio. We were actually using the standard
three-inch diameter system with the low
flow of 120 ml, a minute. That may be
that data, John. I am not sure. But even
that one met the standard of .2 mg per
liter at the low flow.
RESPONSE: Mr. Robeck, Water Supply
Research Laboratory, Cincinnati, Ohio.
I wanted to stress that the Blue Book had
it at .3 mg/i or what you call 300 pg/i,
on the basis of a certain analytical pro-
cedure. And the drinking water standards
of 1972 had it at 200 ug/fc and the new one
is going to be 700 yg/i. They are all
different because of different analytical
methods. So we want to be sure that we
are collecting the data and comparing them
with those same methods each time.
We have had a lot of difficulty in getting
the CCE down that low for much more than
four or five weeks on, say, ordinary Ohio
River water. So there is something here
that doesn't meet the eye. We will have
to talk about it when we get back home.
QUESTION; Mr. John T. Cookson, University
of Maryland, College Park, Maryland. You
mentioned that it might be difficult for a
turbidity of one to be obtained?
RESPONSE: Mr. Convery. One-tenth. The
AWWA said one-tenth.
RESPONSE: Mr. Cookson, University of
Maryland, College Park, Maryland. O.K.
76
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RESPONSE: Mr. Convery. With one, I
don1t see any problem. One-tenth can be
very difficult.
RESPONSE: Mr. Cookson, University of
Maryland, College Park, Maryland. O.K.
I misunderstood you.
RESPONSE: Mr. Robeck, Water Supply
Research Laboratory, Cincinnati, Ohio. I
think it's going to be one-tenth.
RESPONSE: Mr. Convery. Ten percent of
the time.
RESPONSE: Mr. Robeck, Water Supply
Research Laboratory, Cincinnati, Ohio.
we can do it in Duluth, you can do it
there.
If
RESPONSE: Mr. Robert Dean, AWTRL, US-
EPA, Cincinnati, Ohio. I co-authored on
this paper. Remember Tahoe wasn't asked
to do one-tenth. You shouldn't say that
the system isn't capable of meeting one-
tenth when you have never tried.
RESPONSE: Mr. Convery. That's a good
point. But that's still a tough standard.
77
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TREATMENT RELIABILITY AND EFFLUENT QUALITY CONTROL
FOR POTABLE REUSE
H. J. Ongerth
State Sanitary Engineer
J. Crook, Ph.D.
Sanitary Engineering Associate
California State Department of Health
2151 Berkeley Way
Berkeley, California
ABSTRACT
Effluent quality control must be founded upon effluent quality standards. Effluent
quality standards, which have not yet been promulgated, must be considerably more compre-
hensive than the existing or proposed Federal Drinking Water Standards. Present knowl-
edge is limited in several areas, including the identification, monitoring, and health
effects of chemical contaminants. Treatment plant effluent reliability must be of the
highest order for potable reuse. Experience records on plant performance and reliability
and proposals for high order reliability are presented.
INTRODUCTION
It is startling to read in the
printed program that "The objective of
the workshop is to define and establish
priorities for research needed to develop
confidence in the reuse of wastewater for
potable purposes." (Emphasis added.) In
my judgment the workshop objective should
be "to define and establish priorities for
research needed to determine if reuse for
potable purposes is possible, to determine
if it is desirable and cost-effective and
(if established to be possible, desirable
and cost-effectivej, how to design to
assure fail-safe reliability and assured
quality control."
Renovated wastewater is a poor source
for domestic water supply. Every use of
renovated wastewater may impose some pub-
lic health risks. These will scale from
very low order, almost insignificant, to
the high level of risk involved in direct
reuse for potable purposes. In order that
the risk from reuse for potable purposes
be kept to an acceptable level, it is
essential that such reuse schemes have
high orders of reliability and quality
control. Risk analysis techniques should
be applied.
This discussion is dependent upon the
circumstances of delivery of wastewater to
the point of intake of a potable water
system. Domestic water supply intakes are
downstream on river systems from waste
discharges. Time and dilution may be sig-
nificant factors. This practice is often
referred to as "indirect" reuse. In other
situations, groundwaters may contain waste-
water effluents reaching the aquifers
either by percolation from surface spread-
ing or near surface disposal or by direct
injection into an aquifer. This also con-
stitutes an "indirect" reuse. With rela-
tion to groundwaters, time, dilution and
change in constituents and constituent
concentrations by contact with the soil
systems may significantly alter the waste-
water before it reaches a water supply
intake. With both surface and' ground-
waters^ in the limit, wastewa,t«r may reach
a water1 supply ilrteike esstentially un-
eiiaogda. by dilution or oifeer factors.
Up to the present time engiaeeased systems
78
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have careftally avoided a "direct" inter-
relationship of waste discharge to water
supply intake. The following material is
presented without attempting to couple
hazard with particular circumstances of
disposal.
RELIABILITY
The California Department of Health
conducted several studies of reclamation
and sewage treatment plant operations in
the late I960's. These studies revealed
that during the year preceding the
studies, 1*0-60$ of the plants experienced
serious equipment breakdowns, 30$ by-
passed untreated sewage, over 50$ had
power outages, 60-70$ had no emergency
power source, and 70$ had no alarm system.
A 1970 study of k-2 wastewater reclamation
plants utilizing gas chlorination systems
determined that only 15 (36$) of the plants
had the three basic features essential to
assure an uninterrupted supply of chlorine j
namely, spare cylinders, scales, and mani-
fold systems.
A study in the early 1970's of 200
mountain area discharges produced similar
information. For the 12 months preceding
the study, 51$ of the planned discharges
had failures resulting in bypassing or
discharging of untreated or inadequately-
treated sewage due to human error or
mechanical malfunction, while 37$ of the
land disposal systems recorded failures.
Ifaese failures point to the need for
research on equipment design, automation
of controls, and into factors relating to
human motivation.
Considering the consequences of fail-
ure, it is crucial that treatment plant
facilities intended to provide water for
domestic reuse be designed and operated
with a reliability appropriate to the
nature of the reuse. In the ultimate
this reliability must be fail-safe.
Proposed treatment schemes should
include reliability alternatives such as
duplicate treatment units, standby units,
standby replacement equipment, emergency
power supplies, alarm systems, emergency
storage facilities, and flexibility in
piping systems. These are design elements
and cannot assure reliability by them-
selves. Other "non-design" reliability
features are necessary, such as qualified
personnel, preventive maintenance, moni-
toring, and process control programs with
appropriate reporting procedures. A
scheme to assure reliability must include
contingency plans which may provide for
diversion to less demanding reuse, diver-
sion to storage with a pump-back system
to treatment and to provide for any con-
ceivable problem. We must keep in mind
"Murphy's law": Anything that can happen,
will happen - and at the worst possible
time.
California has developed and is
presently in the process of adopting new
regulations for reclaimed wastewater to
be used for irrigation and recreational
impoundments which go beyond present prac-
tice and include the above reliability
features but do not provide for fail-safe
performancelThe reliability requirements
are based, in part, on the "Federal Guide-
lines: Design, Operation and Maintenance
of ¥astewater Treatment Plants" but are
not as specific as the requirements speci-
fied in the EPA supplement to the federal
guidelines entitled "Design Criteria for
Mechanical, Electric, and Fluid System
and Component Reliability." The proposed
California regulations contain, for example,
the following sections:
Alarms
(a) Alarm devices required for vari-
ous unit processes as specified in other
sections of these regulations shall be
installed to provide warning of:
(l) Loss of power from the
normal power supply.
(2) Failure of a biological
treatment process.
(3) Failure of a disinfection
process.
(!»•) Failure of a coagulation
process.
(5) Failure of a filtration
process.
(6) Any other specific process
failure for which warning is required
by the regulatory agency.
(b) All required alarm devices shall
be independent of the normal power supply
of the reclamation plant.
(c) The person to be warned shall be
the plant operator, superintendent, or any
other responsible person designated by the
management of the reclamation plant and
capable of taking prompt corrective action.
79
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(d) Individual alarm devices may be
connected to a master alarm to sound at a
location where it can be conveniently
observed by the attendant. In case the
reclamation plant is not attended full
time, the alarm(s) shall be connected to
sound at a police station, fire station
or other full time service unit with which
arrangements have been made to alert the
person in charge at times the reclamation
plant is unattended.
Power Supply
The power supply shall be provided
with one of the following reliability
features:
(a) Alarm and standby power source.
(b) Alarm and automatically actuated
short-term retention or disposal provisions-
(c) Automatically actuated long-term
storage or disposal provisions.
Emergency Storage-of Disposal
(a) Where short-term retention or
disposal provisions are used as a relia-
bility feature, these shall consist of
facilities reserved for the purpose of
storing or disposing of untreated or par-
tially treated wastewater for at least a
24-hour period. The facilities shall
include all the necessary diversion devices,
provisions for odor control, conduits, and
pumping and pump back equipment. All of
the equipment other than the -pump back
equipment shall be either independent of
the normal power supply or provided with
a standby power source.
(b) Where long-term storage or dis-
posal provisions are used as a reliability
feature, these shall consist of ponds,
reservoirs, percolation areas, downstream
sewers leading to other treatment or dis-
posal facilities or any other facilities
reserved for the purpose of emergency
storage or disposal of untreated or par-
tially treated wastewater. These facili-
ties shall be of sufficient capacity to
provide disposal or storage of wastewater
for at least 20 days, and shall include
all the necessary diversion works, pro-
vision for odor and nuisance control, con-
duits, and pumping and pump back equipment.
All .of the equipment other than the pump
back equipment shall be either independent
of the normal power supply or provided
with a standby power source.
(c) Diversion to a less demanding
reuse is an acceptable alternative to
emergency disposal of partially treated
wastewater provided that the quality of
the partially treated wastewater is suit-
able for the less demanding reuse.
(d) Subject to prior approval by the
regulatory agency, diversion to a dis-
charge point which requires lesser quality
of wastewater is an acceptable alternative
to emergency disposal of partially treated
wastewater.
(e) Automatically actuated short-
term retention or disposal provisions and
automatically actuated long-term storage
or disposal provisions shall include, in
addition to provisions of (a), (b), (c),
or (d) of this section, all the necessary
sensors, instruments, valves and other
devices to enable fully automatic diver-
sion of untreated or partially treated
wastewater to approved emergency storage
or disposal in the event of failure of a
treatment process, and a manual reset to
prevent automatic restart until the fail-
ure is corrected. '•<
Disinfection
AH disinfection unit processes where
chlorine is used as the disinfectant shall
be provided with the following features
for uninterrupted chlorine feed: standby
chlorine supply, manifold systems to con-
nect chlorine cylinders, chlorine scales,
and automatic devices for switching over
to full chlorine cylinders. Automatic
residual control of chlorine dosage,
automatic measuring and recording of
chlorine residual, and hydraulic perfor-
mance studies also may be required. AH
disinfection unit processes where chlorine
is used as the disinfectant also shall be
provided with one of the following relia-
bility features:
(a) Alarm and standby chlorinator.
(b) Alarm, short-term retention or
disposal provisions and standby replace-
ment equipment.
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(c) Alarm and long-term storage or
disposal provisions.
(d) Automatically actuated long-
term storage or disposal provisions.
(e) Alarm and multiple point chlori-
nation, each with independent power source,
separate chlorinator and separate chlorine
supply.
As stated earlier these criteria are
designed to provide a much higher degree
of reliability than now practiced, but do
not provide for fail-safe performance.
Moreover, reliability of process is a
matter separate and distinct from effluent
control.
EFFLUEWT CONTROL
As with all waste treatment facili-
ties, effluent quality control is neces-
sary - in this case, critically so. For
the present, however, this subject cannot
be explicitly discussed because essential
knowledge is lacking for a definitive dis-
cussion. The ingredients to establish
quality control are: (l) constituents
identified, (2) limits established,
(3) knowledge of capability of treatment
process to produce desired removals.
As stated earlier, wastewater con-
stitutes a poor source of domestic water
supply. This is so because it is apt to
contain many potentially harmful sub-
stances of varying concentrations. In
general terms, the constituents of concern
are heavy metals and other toxicants,
residual organics, and pathogens - includ-
ing enteroviruses. To make such a raw
material suitable for domestic use, treat-
ment processes must be capable of produc-
ing predetermined results. Research is
needed to identify constituents, on toxi-
cology of these constituents, and on
process development and design. Finally,
demonstration projects must be carried on
to prove out the entire process in full-
scale operations.
In essence, quality control measures
are those efforts made to ensure that a
final product meets or exceeds previously
set standards. In the laboratory these
efforts include selection of methods,
training of analysts, calibration of
instruments, and standardization of re-
agents, to name but a few. Wastewater
reclamation has as its goal production of
an effluent with certain measurable char-
acteristics. To achieve this goal the
same basic steps are necessary: the
treatment method chosen must be capable
of producing the desired effect; operators
must be properly trained to handle the
process; equipment must be calibrated and
maintained in optimum condition; and the
entire process must be monitored in such
a manner that possible problems are identi-
fied before they become real problems.
Instrumentation must be highly accurate
and reliable, provide for continuous
monitoring of most parameters and have
provision for continual check and calibra-
tion. Analytical methods and instrumenta-
tion capable of real-time production of
information must be developed to provide
precise and timely control over treatment
processes.
As automation increases and becomes
more complex, does reliability decrease?
Other questions with relation to monitor-
ing: Is bioassay as a continuous monitor-
ing process feasible; should all reuse
systems incorporate batch type systems
for release of effluent; to what extent
must prospective health status studies be
applied to populations receiving water
supply derived from renovated wastewater?
A part of the process of effluent
control must begin at the point at which
wastes are introduced into the system.
Source control is an obvious necessity
though its value is limited. Source con-
trol may take care of the obvious, but
what about the unk-unks? With relation
to source control, how do we educate the
public to eliminate indiscriminate dumping
of hazardous material into sewerage systems?
Although many compounds of potential
concern remain to be identified and limits
and treatment capability established, we
do have something to start with. The U.S.,
the U.S.S.R., andW.H.O. have each devel-
oped standards for constituents in drink-
ing water. The U.S. and W.H.O. standards
are similar. Among other things, they
include a limited coverage for organic con-
stituents. The U.S. standards, in particu-
lar, were developed on the basis of start-
ing with the best available raw water
quality. It is not surprising, therefore,
that they are not broad enough in coverage
to provide a suitable set of quality re-
quirements for treatment of wastewater for
81
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domestic purposes. Further, it is of
interest to note that the U.S.S.R. stan-
dards cover 297 constituents, the major
number of which are for the specific
organic compounds. However, most of the
U.S.S.R. standards are based on aesthetic
and not health considerations.
Hie KPA findings of 66 compounds in
only 2% of the organics in the water
supply at New Orleans gives rise to great
uncertainty about the possibilities for
future reuse.
Concerns about the role of entero-
viruses in disease transmission through
the water route poses a special problem.
Current water treatment processes are
generally believed to be providing safe
water starting with raw water sources now
in general use. The infectious hepatitis
waterborne outbreak at New Delhi gives
reason for some special concern, however.
In that situation some vagaries of stream
flow resulted in changes which brought
highly polluted water directly to the
water supply intake, said to be a quite
unusual situation. The water treatment
plant is said to have produced water meet-
ing the coliform standards but a major
infectious hepatitis outbreak resulted.
If wastewaters are to be used as a source
of domestic water, there must be some kind
of better understanding of the virus re-
moval capability of various processes
under a variety of operating conditions,
or there must be a capability for routine-
ly monitoring virus, or both. Without
this, the effectiveness and reliability
of reuse process to control virus will be
in doubt. It is significant to note that,
with relation to almost all water quality
parameters other than virus in both domes-
tic water and wastewater treatment, per-
formance is monitored on the basis of
direct water quality measurements.
One aspect of effluent control is
activity by a regulatory agency. Unques-
tionably, regulatory activity is a neces-
sity to accomplish reliable and effective
performance. On the basis of experiences
with one major groundwater recharge proj-
ect, about $5jOOO worth of regulatory
effort was spent on a 15 MGD plant.
Beyond this, it is estimated that for
this size plant it would cost about $1,000
a year for regulatory activities on an on-
going basis. In round figures, that
amounts to $75 per year per MGD capacity.
Somehow or other regulatory agencies must
receive additional funding for this
activity.
CONCLUSION
Present wastewater plants are neither
designed nor operated to be fail-safe,
though this capability is a necessity for
direct reuse. Further, effluent quality
control is essential to assure satisfactory
plant performance. Much information is
needed. We need to know what constituents
are apt to be in waste streams and at what
concentrations. We need data on acute and
chronic toxicity for these constituents in
order to establish constituent limits.
With this information, it will be possible
to determine removal capability for the
constituent of concern with specific
treatment chains under conditions to be
encountered in practice. With this, prob-
lems and limitations of effluent quality
control can be discussed - but not today.
The two highest research priorities
are:
1. Develop information concerning
organics in existing domestic water supply
sources and provide necessary controls.
This is considered to be an urgent need.
2. Study water management techniques
for maximum reuse of wastewater taking
into consideration health factors and costs
in terms of dollars and energy.
DISCUSSION
QUESTION: Mr. Joseph Roesler, EPA-NERC,
Cincinnati, Ohio. I would like to make a
few comments and then ask my questions.
First, I would like to distinguish auto-
matic process control from manual process
control because I' am involved in automatic
process control. Automatic process control
really does not replace the operator. It
sort of takes him and nudges him along the
straight and narrow line to improve the
plant reliability and possibly the plant
performance, improve costs, and also pro-
vide some quality Insurance.
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The second thing is if plant effluents
are monitored it may also provide plant
insurance and reliability, if the monitor-
ing is automatic.
There are two questions I" have to ask
you: What are your priorities for auto-
mation of reuse plants such as the one in
Orange County? Which control strategies
do you feel would be the highest priori-
ties? My second question is: For the
effluents, which parameters would you feel
would be most suitable and of the highest
priority for automation if you had your
choice of anything?
RESPONSE: Mr. Ongerth. Well, I can cope
better with the first question than the
second one, because I can readily say to
the first one, I don't know. I don't
know whether we get a greater reliability
with automated controls or not. I think
this is one of the things we need to do
some work on to have better information,
to learn what the possibilities are. I
know that automatic controls aren't the
whole answer.
Maybe Frank Dryden would give us the
benefit of an explanation for the break-
down at Whittier Narrows about a month
ago.
COMMENT: Mr. Dryden, Sanitation District
of L.A. County, Whittier, California.
After almost thirteen years of a very suc-
cessful operation, we did have the failure
which was related to the automation of
the system in that we do not have operator
attendance twenty-four hours a day. We
have an AID alarm system by which certain
plant signals are transmitted to an answer-
ing service, and one of those kinds of sig-
nals is power failure. The answering ser-
vice has a list of people to call, and
they call the operator or someone else who
comes and starts the plant up again after
everything is checked out, because you
can't have a power failure and start every-
thing up automatically because of the load
on the system. You have to do it in se-
quence .
The failure was in the ATD transmission
system. They, in fact, knew that their
line was not functioning properly and
failed to advise us. It happened to coin-
cide during the period they were working
on repairing this system that a power
outage did occur at night, and because no
alarm reached the answering service, we
were not advised. The blowers did go off.
The plant ultimately began discharging
what would have to be considered a rather
poor quality effluent which was isolated
by the next morning and treated. But it
was the kind of breakdown which occurs.
The point I would like to make is that
neither Whittier Narrows nor any other
plant I know of has been, in fact, designed
for fail/safe operation. They have been
designed for highly reliable operation;
they are designed with certain safeguards
built into them for a reasonable amount of
protection;. But years of previous re-
search, for that matter, on the applications
of primary effluents to spreading basins,
long before Whittier Narrows was designed,
indicate that there isn't any great hazard
from even that particular kind of thing,
especially for very short periods.
So there has not been an emphasis as
there would have to be on an actual fail/
safe system. I agree wholeheartedly with
Henry and the others who have said that
fail/safe systems have not been put to-
gether and demonstrated. 'They haven't
even been adequately conceived. That is
one of the things that I hope this con-
ference will take a hard look at—what
it does take to have a fail/safe system.
When we take a hard look at it, we may
come to the conclusion we can't afford it.
But the fact is that it hasn't been con-
ceived or worked on yet, and when we talk
about the potential for potable systems we
certainly have to look at the fail/safe
controls.
RESPONSE: Mr. Ongerth. I didn't answer
the second question. If you want me to
try, it won't be a very good answer either.
I can*t propose automatic monitoring of
some constituents that I think would give
us the kind of information we ought to
have. I think this is another area where
we need to develop more information and
more knowledge. So, really I can't answer
either question.
COMMENT: Mr. Hillel I. Shuval, Director,
Environmental Health Laboratory, Hebrew
University, Jerusalem, Israel. I would
like to comment on this debate with the
straw man that Henry has set up.
83
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I think actually what you have proved,
and what John Convery has proved, Is that
actual plants are not very reliable. How-
ever, John has proved that you can design
a reliable plant if you have to and you
can operate it in that way if you decide
that you must. I think that the conclu-
sion is actually Frank Dryden's conclusion,
that if we are going to achieve the re-
liability that we all know we need for re-
use plants, we have to achieve the type
of reliability that John Convery says is
technically obtainable and we have to de-
sign those plants at a higher level than
we are used to. There are consulting
engineers who say, "Yes, we'll have to
design better." They certainly had better
design better, because they cannot get
away with a reuse plant that will work
only on the average. The same thing goes
for fail/safeness. Nobody has tried to
design a fail/safe plant, and if we are
going to have reuse, we cannot afford to
have even minor breakdowns.
One of the things, of course, that we
will discuss in this Workshop is monitor-
ing. One of my proposals from a long time
back has been that the monitoring should
be conceptually different from the water
industry's concept of monitoring. The
water industry today monitors ex post
facto: after they deliver the water, they
get the results of the test. This is an
untenable position for a delicate product.
Even in the milk industry, you've got to
get the results of each of the major tests
before you deliver the milk. You at least
have to show that the milk is pasteurized.
So you get a phosphatase test, and possibly,
a bacteriological test before you deliver
the milk.
So I think it's a whole concept of fail/
safe design, a higher level of operational
sophistication, monitoring which gives you
the results before you deliver the pro-
duct, with at least a minimum of a twenty-
four-hour hold-up in the wet well so you
can complete a good part of your chemical
and microbiological monitoring tests. I
think a good comparison is the industrial
example of the atomic energy industry
which changed the concept of the electric
power industry. The average electric
power plant has a history of work accidents
and failures and different breakdowns be-
cause it is run on the loose basis of many
other industries. The atomic energy indus-
try, which has been considered a very
risky industry from the very beginning,
has had a better accident rate and fewer
breakdowns than any other industry be-
cause they have been so aware of their
stiff requirements.
QUESTION: Mr. Paul D. Haney, Black &
Veatch, Kansas City, Missouri. You men-
tioned Dan Okun. Is he thinking of mul-
tiple pipe distribution systems like, for
example, dual systems?
RESPONSE: Mr. Ongerth. I am sure that
is what Dan is thinking about. Yes. I
think that is what he proposed for Singa-
pore. I think this is in some of his
writings.
QUESTION: Mr. Haney, Black & Veatch,
Kansas City, Missouri. Well, what do you
think of that?
RESPONSE: Mr. Ongerth. I think it has
its place in the picture. This disposes
of the concerns about the organics, for
example, in water. If you can produce a
biologically safe secondary supply, and
if you can cope with the problem of having
a dual piping system, than you have an
opportunity for reuse in what Schmidt
this morning called nonpotable domestic
use. I think that has its place.
On Catalina Island, there has been a
dual water system for years, with the
secondary supply being a salt-water supply
for toilet flushing and showers. I think
it's the Southern California Edison that
now owns the water supply on the island,
and they are in the process of abandoning
the salt-water supply because of the cor-
rosion problems from salt water. They
are going to reclaim effluent, recharge
the groundwater basin and pick it up a
considerable distance downstream, and that
will be their secondary supply. I think
this is a very satisfactory arrangement.
COMMENT: Mr. Richard D. Heaton, Denver
Water Department, Denver, Colorado. You
mentioned your preference for groundwater
recharge, and I think of many exceptions.
Two stand out in my mind, especially in
this area. First, the geology is not
amenable to groundwater recharge and we do
not have the large aquifer underlying
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Denver. Secondly, western water law,
specifically the appropriation doctrine,
confuses the issue. We are not sure that
if we can put jc gallons in the ground we
are allowed to take jc gallons out. If it
goes in the ground, we are not sure to
whom it belongs.
RESPONSE: Mr. Ongerth. California has
a replenishment district law with which
I am not at all familiar. Maybe there is
something in the California law that would
be politically possible for the future.
that is certainly a problem. If you pay
for recharging it and then you don't con-
trol the withdrawals, that is not a very
profitable exercise.
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HEALTH ASPECTS OF REUSING WASTEWATER
FOR POTABLE PURPOSES - U.S. EXPERIENCE
L. J. McCabe
Chief, Criteria Development Branch
Water Supply Research Laboratory
Environmental Protection Agency
Cincinnati, Ohio 45268
ABSTRACT
It is considered that this is a new water resource development and the burden of
proof on the safety of such water will be on the utility proposing such use. Types of
safety testing of new products are reviewed and cost estimated.
Current water supply health effects research is reviewed and applicability to reuse
suggested. Resolved and unresolved problems are outlined.
The most plausable reuse situations are those in which only acute effects need to be
considered. The economics of water supply indicate that potable reuse would be cost-
effective only in unique situations. Some utility will have to take the pledge to pro-
duce water of drinking water quality from sewage for an extended period to demonstrate
that it can be done. To date, no one has taken the pledge.
INTRODUCTION
The Environmental Protection Agency
has developed a policy that is opposed to
direct recycling for drinking water. All
drinking water standards developed to date
have cautioned that the limits were set in
consideration of using the best source of
raw water and cannot be used for guidance
for wastewater reuse. Thus, any utility
that proposes wastewater reuse for drink-
ing water in the immediate future will be
required to demonstrate the safety of the
processes envisioned without a concensus of
regulatory authorities on what will consti-
tute a potable water.
A utility gives an implied warranty of
the safety of the drinking water they pro-
duce and when there are departures from the
current state of the art, there will not be
much of a defense to fall back on if con-
sumers claim damage from using the water.
To provide an adequate defense would
require a tremendous amount of analytical
work on the water produced. Data would
have to be available on any biological or
chemical contaminant that someone could
think of. The minimal list provided in
the drinking water standards will not be
enough. It is likely that the analytical
cost will exceed the treatment cost. If
damages were sought by a consumer, expert
witnesses would be required on any con-
ceivable illness of man that could be
enforced to be caused or aggravated by
anything that could be measured in water.
Drinking water produced directly from
wastewater could be considered to be a new
product with many new food additives. Some
estimates have been made on the cost of
testing new products. Chemical Week re-
ported estimates of $250,000 to $500,000.
It seem obvious that gradual changes
will have to be made in trie use of waste-
water as a resource. Some uses may have
86
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a long enough history that they can be con-
sidered as part of the state of the art.
Industrial reuse has been practiced for
enough purposes and in enough locations to
be accepted. Much of this has been within
plant recycling but the distribution of
wastewater for industrial reuse is becoming
accepted. The use of treated wastewater
for recharge to prevent salt water intru-
sion has been accepted, but the recharge
into aquafers that can be used for water
supply will be regulated under the new
Safe Drinking Water Act.
It has been stated that direct reuse
of wastewater is only a difference of de-
gree from what is practiced now by many
cities that use the major rivers of the
country for a raw water source. As indi-
cated, the difference of degree makes a
difficult problem for a utility but
research that is conducted for drinking
water purposes should have some applica-
tion to the reuse situation. EPA has a
rather structured research planning sys-
tem. This begins with statements of
research needs from the regional offices,
which are combined into Environmental
Research Objective Statements in Washing-
ton. We receive these EROS's and develop
a Research Objective Achievement Plan.
Three of these ROAP's have application to
the reuse problem.
Reuse Related Research
One of the ROAP's in our Water Sup-
ply Research Program is called "Microbio-
logical Contamiants of Water Supplies"
and there are several research tasks
within this ROAP that do impact on the
health effects of reusing sewage for
drinking water.
The first of these tasks is one which
has concerned itself with providing a tech-
nique for concentrating and recovering
viruses from drinking water. Concern over
the potential problem, and I stress poten-
tial, of viruses in drinking water con-
tinues to be expressed by a few vocal
individuals. Whether or not this is a
real problem remains to be determined and
one way to attempt to determine if it
really is a problem is to look for viruses
in drinking water. In order to do this,
one must have a technique for concentrating
and recovering low numbers of viruses from
large volumes of water. We have now
researched this to a point where we have a
method for the detection of viruses in
drinking water, which will appear as a
Tentative Standard Method in the forthcom-
ing 14th edition of Standard Methods. This
technique could, we believe, be effectively
used to monitor for viruses in drinking
water made from sewage, if we ever have to
go to that extreme.
The system we use to monitor viruses
in drinking water basically consists of
passing water under pressure through
microporous filter media to which the
viruses adsorb. The viruses are not
sieved out of the water by virtue of the
pore size of the filters, in fact the fil-
ters are 36 to 286 times as large as most
enteric viruses. The viruses are adsorbed
to the microporous filters by simply adjust-
ing the pH of the input water. Once vir-
uses have been adsorbed to the filters they
can be eluted from the filter with a small
volume of an alkaline pH buffer. By appro-
priate manipulation we can concentrate the
viruses in 500 gallons of water into a
20 ml volume. This entire 20 ml volume
can readily be assayed in tissue cultures
or animals for viruses. W;Lth this system
we have been able to detect one virus unit
in 100 gallons of Cincinnati tap water
which was seeded with one virus per 100
gallons, if we sampled 500 gallons.
We have been evaluating a microporous
filter system in our laboratory and in field
surveys for viruses in drinking water.
These are Balston filters, made of fiber-
glass-epoxy resin and are about 2 1/2
inches long and 1 inch in diameter and
have an 8 micron porosity. They are nor-
mally used as a three filter unit system
and we have not experienced filter clogging
problems with this system with samples as
large as 500 gallons of drinking water.
I mentioned that we have used this
type of filter system and others, in field
studies for viruses in drinking water.
This field study or survey is another
task which relates indirectly to the health
aspects of reuse problems. For the past
1 1/2 years we have been conducting a virus
in water study of finished water from sev-
eral communities in the United States and
are continuing these studies. These stud-
ies are a continuation of work conducted in
our three field laboratories at an earlier
date, before these lab's functions were
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transferred to Cincinnati. The studies
have a two-fold purpose - (1) to determine
if human enteric viruses can be detected in
treated finished drinking water; (2) to
field test the virus concentrating equip-
ment and procedures as they are improved by
ongoing research in our laboratory- In
these current studies a primary criterion
for selection of sites was the plant's
utilization of a surface source water hav-
ing high fecal coliform counts - as near to
the sewage reuse as we could find. So far
we have collected seventy-five samples and
in no case have we detected viruses in the
finished water. Our sample sizes have
ranged up to 500 gallons. The fact that
these water treatment systems were chal-
lenged by a very poor source water on
numerous occasions and yet produced a
finished water in which no viruses could
be found would seem to give a vote of con-
fidence to the adequacy of virus removal of
good conventional treatment. One would
certainly hope that "advanced" treatment
processes, as used in reclaimed water pro-
cesses, would do a better job, and thereby
assure us that they too eliminated a virus
problem, if there is indeed such a problem.
One final task in this ROAP that re-
lates to reuse should be mentioned.
There is a need to develop and evaluate
techniques that can be used to monitor
the "infectious disease" history of popu-
lations who may use or be exposed to
reused sewage. We are funding a research
group that is investigating the use of
the serological-epidemiological approach
to determine the health risk of employ-
ment as a sewer maintenance worker as
compared to road maintenance workers.
One would expect that sewer workers would
have a higher risk of exposure to infec-
tious agents in sewage than would road
workers and that this risk could be mea-
sured by comparing the "infection his-
tory" of the two groups. "Infection
history" does not necessarily mean sick-
ness, it means exposure to, and infection
with, a biological agent. The individual
may or may not become sick, but in all
likelihood he will develop an immunity
to the agent. This immunity can be
determined by serological tests on his
blood serum and if enough of the proper
tests are done, can indicate the biolo-
gical agents which have infected the
individual over the years. If we can
demonstrate the usefulness of this tech-
nique it certainly can be considered as
a technique for monitoring the infectious
disease exposure to persons contacting
reused sewage.
The knowledge and data obtained in
setting health-related standards for
drinking water can certainly be used,
at least initially, in the evaluation of
wastewater that is to be recycled for do-
mestic uses. We should remember, however,
the limitations of these data. The Drink-
ing Water Standards cover only a small
number of constituents and the speciation
or matrix effects may be different in
reclaimed wastewater than presently used
drinking waters.
The research being conducted and
planned by EPA on the health effects of
various inorganic contaminants in drink-
ing water will be discussed briefly to
acquaint you with our approach to obtain-
ing the needed data. This will provide,
at least, a point to begin discussions
on whether this approach should be applied
to reclaimed wastewater and what areas are
of a mutual interest so that duplication
can be avoided.
Our health effects research on inor-
ganic contaminants can basically be
divided into five broad categories:
(1) occurrence;
(2) body burden studies;
(3) toxicological studies;
(4) epidemiological studies; and
(5) rapid screening for mutagens
and carcinogens.
Our research up to the present has
primarily been to obtain health effects
data to strengthen the present inorganic
standards. Before we can conduct studies
on other contaminants we must first iden-
tify and quantitate the contaminants to
establish a priority for study. We are
currently sampling water supplies in 35
areas of the country to obtain these
data. We felt that multi-elemental ana-
lytical technology which has been used
successfully in analyzing other media
such as rock, soil, air, had reached the
point that it could be successfully
applied to water. The advantage of a
multi-elemental technique is the measure-
88
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ment, simultaneously, of a large number
of elements in the ppb or less concentra-
tion. The problem in water analysis is
that of limited experience by analysts in
this field. When determining concentra-
tions in the ppb range, contamination in
sampling and preparation are of course a
major source for error. Other problems
relate to quality control and appropriate
internal standards. We are currently
contracting with Dr. Paul C. Simms of
Purdue University for this analytical
work. He is using proton-induced X-ray
emission, which is capable of determin-
ing 82 elements (Silicon through plu-
tonium). Approximately 30 elements can
be determined at a sensitivity of ± 1 ppb
at the present time. With additional
instrument modification and appropriate
standards, it is hoped that the addi-
tional elements can be determined at
the same detection level in the future.
Another way to approach the problem
of setting priorities on constituents to
study is to determine human body burdens
and look at all routes of exposure to
arrive at the contribution from water.
This has been done to a small extent but
more will be done in the future. The
problem in studying living populations
is to select a tissue such as scalp hair
or nails which will represent body bur-
den for the particular element desired
and which will easily be given up by the
population sampled. Autopsy studies
will also yield important information
in this regard.
Our toxicological studies are de-
signed to measure specific end points
according to the type of effect antici-
pated. These studies have been with
single contaminants ingested at varying
dosages. Our in-house capabilities
include an animal model to study effects
on brain function. This has been used
to substantiate the mercury standard and
is currently used to study the effects
of manganese and lead. Other animal
studies, completed or planned, include
nitrate, cadmium, selenium, molybdenum,
silica, and barium. Future studies
will consider the possible interactions
of various contaminants.
A question we consider of import-
ance, especially in the area of water
quality and chronic disease is the ques-
tion of bioavailability of various
inorganics in water as opposed to food.
For most inorganics, exposure via food
is greater than that obtained by drink-
ing water; however, metals in water may
be more readily available. Bioavaila-
bility can be studied in animal models.
While animals are useful for study-
ing mechanisms and providing good data
that can be extrapolated to man, epidemi-
ologic studies have the advantage (and
disadvantage) of looking at man directly
over a long exposure period and taking
into account all the conflicting variables
present in real life. This approach was
used by us to study the effects of nitrate
and lead in drinking water and will be used
to study populations exposed to barium in
ground water. Our major effort in this
area has been to relate water quality to
chronic disease problems such as cadrio-
vascular. We are currently cooperating
with the National Heart and Lung Institute
on a prospective study of trace elements
in water and cardiovascular function of
4200 individuals in 35 areas of the coun-
try.
Our work in rapid screening tech-
niques for the detection of mutagens and
carcinogens has been limited to the use
of bacterial indicators and cultured mamma-
lian cells. A grantee at Louisiana State
University Medical Center in New Orleans
is using Bruce Ames salmonella testing
strains to screen raw and treated water
from the lower Mississippi River for the
present of carcinogens. The water is
assayed both directly and after: liver-
activation to determine if the tester
strains revert to histidine independence.
The grantee is also investigating a number
of mammalian cell lines which could be
used to assay water samples. In-house, we
are currently screening a number of inor-
ganics to assess mutagenic potential.
These include arsenic, berryllium, cadmium,
cobalt, nickel, selenium, barium, chromium,
copper, lead, manganese, mercury, and zinc.
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Rapid screening techniques such as
these can be applied to wastewater reuse.
Ames testing system provides results in
approximately two days and is quite easy
to use. The problem of course is determin-
ing which screening method will provide
consistently low-false negatives. These
systems could be used for monitoring parr1
ticularly with ground water recharge which
allows for a less dynamic cycle.
The third ROAP of interest concerns
the Occurrence and Effects of Organic
Contaminants in Drinking Water. The
major thrust of this project is to ob-
tain concentrates of organic chemicals
from drinking water and then subject
these total concentrates to toxicity
testing. We have considered several
techniques of concentration and have
put most effort into reverse osmosis.
A report from a contractor, Gulf South
Research Institute, has recently been
received - Evaluation of Semipermeable
Membranes from Concentration of Organic
Contaminants in Drinking Water. We
have been collecting organic concen-
trates from Cincinnati drinking water
on a regular bases for over a year.
A cellulose acetate membrane is used
for the first recovery and then the
permeate is processed by a Permasep
membrane. The concentrate from both
processes is lyophilized for further
reduction in volume. Both RO concen-
trates are then extracted with pentane
and methylene chloride to remove the
organics from the salts. We have been
able to only partially complete what
we want to do with these concentrates,
but are satisfied that useful data can
be obtained with the material recovered
in this way. Some of the chemical
characterization has been completed
but a problem that must be resolved
is an appropriate blank for this pro-
cessing. The water comes in contact
with several materials in the pro-
cessing and contamination does occur
and must be quantified. The toxicity
testing has started including acute
toxicity, mutagenicity screening, and
carcinogenicity pre-screening. The
amount of material recovered limits
what can be done on each sample. A
sample for toxicity testing cannot
have complete chemical characteriza-
tion and only partial chemical workup
is done on some samples. As the
screen techniques are better under-
stood, it may be possible to reduce
the material required.
The organic recovery and toxicity
testing studies are being extended to
five other cities and the RFP's for
these are out. We also have a Re-
quest for Proposal to better separate
the salt from the organic material.
We have felt that the study of
of combination of the total organics in
the water would provide the most useful
data. Synergenic effects would be auto-
matically considered and the research
might lead to a general organic parameter
that could be used to control water quali-
ty. There have been improvements in
organic chemistry that make it difficult
to keep to this research plan. Specific
identification can now be made with the
Gas Chromatograph/Mass Spectrophotometer.
When specific identification is done and
quantities determined, interest is devel-
oped in obtaining specific toxicity data
on the compounds. We are therefore
carrying out research on the toxicity of
haloethers and the halogenated aromatic
hydrocarbons.
The most interesting development
was the finding of chloroform and the
other methanes using a volatile organic
analyzer developed by the Methods Develop-
ment and Quality Assurance Research
Laboratory. We used this tehnique on the
New Orleans drinking water and are con-
tinuing in the National Organic Reconnais-
sance Survey that followed. This workload
has postponed some of the things we had
planned to do but it also questions the
possibility of collecting the total of
organic chemicals by one technique. It
seems unlikely that one method will re-
cover all organics and there will have to
be a blending of fractions for toxicity
testing. Nothing is known about the
toxicity of the bromodichloromethane and
dibromochloromethane and this will re-
quire some specific toxicity workups.
There are three main objectives to
our research on organics - (1) determine
the compounds present in tap water; (2)
elucidation of the toxic properties of
these compounds singly and in combination
in appropriate animal models, and (3) moni-
90
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torlng of human populations to verify pre-
dicted presence or absence of disease.
All of this will be applicable to waste-
water reuse.
Reuse Research
We also have a ROAP on the Health
Effects Associated with Consumption of
Renovated Water that is in its second
year of funding. It is designed to
follow up on developments from the
water supply research and apply the
techniques to treated wastewater. The
organic chemical concentration tech-
niques are being applied to advanced
waste treatment effluents. The total
non-volatile organic carbon (TNVOC)
is about 2 ppm in Cincinnati and New
Orleans drinking water. When sampled
the Dallas water was down to one ppm
but the others all had more TNVOC;
Tahoe - 5 to 9; Blue Plains - 5, and
Pomona - 3 ppm. The Bellar VGA tech-
nique was also applied to the product
waters of these plants and 14 to 18
compounds identified; this could be
compared to the 17 reported for New
Orleans. Preliminary judgment would
be that the AWT effluents have more
organic contaminants than some drink-
ing waters.
We have also had the multi-ele-
mental analytical technology applied
to the Blue Plains effluent. Three
diurnal cycles were obtained using
proton-induced X-ray emissions. In
this situation we were not satisfied
that useful data had been obtained,
but it would seem that for the metals
with limits in the drinking water
standards the effluent would meet the
limits on average but not consistently.
The limits are based on chronic intake
but it may also be necessary to develop
a one sample limit to control peak
concentrations.
We are evaluating the component
cost of water supply to see how reuse
might work into the water resource
development. A concern has developed
on the premise of "economics of scale."
It is recognized that this applies to
the treatment plant but not to the
total distribution system. To control
transportation and distribution cost
it might be best to develop new sources
at the extremeties of the distribution
system and reuse might have a role in
this.
Another research task is in coop-
eration with EPA industrial waste
research. Recycling systems are being
developed for all industries and there
are particular health effects problems
in food processing. We will evaluate
the effects of recycling in a poultry
plant. The judgment on health effects
will be based on the evaluation of the
finished product to show that is is no
worse than the regular product. Once
the first bird is processed? there is
an averaging out of contamination with
all the subsequent birds processed, but
recycling can also retain some of the
chemicals that are used in the plant
that normally do not have contact with
the product.
SUMMARY
It should be obvious that it will
take some time before there will be
enough research completed to allow reuse for
potable purposes. When chronic toxici-
ties must be considered there must be
research on many aspects of the problem
at very low concentrations. If there
are reuse situations where only acute
effects need to be considered, it should
be possible to reuse wastewater sooner.
Continued consumption of the water
would not occur in recreational use;
it might be possible in this situation
to consider only the infectious disease
problems. This same idea could also be
applied to dual water systems with the
lower grade water only safe for acute
exposure and of such quality that the
difference could be detected by taste.
When the complexity of the problem
is appreciated, it can be seen that the
reuse idea will only apply in a unique
situation for some time. It will
clearly have to be a least-cost situation
by a wide margin to justify the long-term
risk that may be involved.
To evaluate the possibility Q£ reuse,
it will be necessary to produce a potable
water for an extended period without
using it for potable purposes. No utili-
ties seem to be ready to do this.
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DISCUSSION
COMMENT: Mr. Dolloff Fred Bishop, U.S.
EPA, Cincinnati, Ohio. Lee, I would like
to make one comment on the TOC residuals
that you were talking about in the AWT
effluents. First, you cited Dallas which
was a specific, high quality treatment se-
quence aimed at getting close to the pot-
able reuse approach. The other AWT systems
that you cited were systems which were de-
signed to meet some other standard. For
instance, Lake Tahoe was not designed for
producing as low a residual organic carbon
as possible. The Blue Plains facilities,
which you alluded to, were also either the
advanced biological systems which had no
carbon adsorption in them, or the physical-
chemical systems on the raw wastewater
which, again, did not have any final or-
ganic polishing steps such as ozonation.
Under these sequences then, the 5 mg/&
TOC level which you suggested you found
there could be expected. With one more
existing technology step, it should be
possible to reduce these levels to the
order of 2 to 3 mg/Jt that you are finding
in many of the surface-water supplies in
the United States.
RESPONSE: Mr. McCabe. May I respond to
that? Are you going to ask a question
about that?
RESPONSE: Mr. Bishop, U.S. EPA, Cincin-
nati, Ohio. No. I was stating that as a
source of information.
RESPONSE: Mr. McCabe. That's my pro-
blem. That's why I said at the very end
of my talk that somebody is going to have
to take the pledge, "I'm going to make
drinking water for you long enough to
test." This has not been done to date.
Where are you going to do it? Everybody
says, "Oh, go to Tahoe. They've got a
great effluent there."
COMMENT: Mr. Bishop, U.S. EPA, Cincin-
nati, Ohio. We haven't put in a system
until just recently. For instance, you
have the Blue Plains plant now and there
is a pilot chain which is designed to pro-
duce high quality effluent which we hope
will be approximating that for drinking
water, and that is what its specific
assignment is. So perhaps-we will be able
to give you some of those answers.
RESPONSE: Mr. McCabe. Yes, but my
four years of needed health effects re-
search don't start until you're ready with
the effluent.
COMMENT: Mr. Bishop, U.S. EPA, Cincin-
nati, Ohio. The major point that I would
like to make is that I think we may be
missing the whole issue in today's discus-
sion. We have been arguing two sides of
perhaps the same coin. The residual
trace organics and components which we
don't wish in our reuse effluents, and
that we are concerned about, are also
found in our surface-water supplies. They
may be diluted, but they are still there.
And if we find that they are undesirable
from an ecological point of view or from
a human health effects point of view, we
are probably going to have to go after
them in the water supplies as well as in
the treatment plant. We may not be able
to get off this hook no matter how we look
at it,
RESPONSE: Mr. McCabe. But the utility
won't get sued in the meantime because he
is practicing the current state of the art.
COMMENT: Mr. Bishop, U.S. EPA, Cincin-
nati, Ohio. You're sort of arguing the
legal aspect rather than a true health
effects aspect.
RESPONSE: Mr. McCabe. Well, Mr. Quarles
went up to Boston to talk about my research,
so I figured I would come down and talk
about the law.
QUESTION: Professor Shuval, Director,
Environmental Health Laboratory, Jerusalem,
Israel. I realize that we are treading on
administrative ground, but I tend to agree
with Fred Bishop that the issue we should
be discussing here is the scientific issue
and not the administrative issue. And I
think that you pointed out that the re-
search program that you are carrying out
now will provide some of the answers for
reuse of water, whether it is direct or
indirect. If we accept the reality that
we are living in a world where we have in-
direct reuse of water (I think the figure
was given that something like 50- to 100
million people are using more or less reuse
water), then we must have the answer to:
What are the health effects of using water
directly or indirectly? What is the treat-
ment technology that is required
92
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to remove these things? I think it is al-
most administrative quibbling to say,
"Well, it's premature to think about
direct reuse." You still have to have the
answers whether you never go into direct
reuse. You still must know how to con-
centrate the organics; you still must know
how to fractionate them; you still have to
know which are the toxic ones; you still
have to know the effects of the mixed bag
and each one separately; and you have to
know how to remove them if they are metals.
RESPONSE: Mr. McCabe. But you don't
have to assay AWT effluents unless you're
planning to use the water for human con-
sumption.
COMMENT: Professor Shuval, Director,
Environmental Health Laboratory, Jerusalem,
Israel. Yes, you do, because you have to
develop a treatment technology. I don't
care whether you call it advance waste
treatment or advance water treatment; it's
the same thing. But you've got to remove
these things, and whether you call it
waste treatment technology or water treat-
ment technology, it's exactly the same
technology. Whether you put your carbon
filters on the waste treatment plant and
also on the water treatment plant, or you
bring them together, you must have a tech-
nology that will remove the total organics
or the nonvolatile organics as well as the
volatile organics and the metals and all
of the other things that you want to get
rid of.
We faced this recently at the Amsterdam
meeting of the WHO where we came to the
conclusion that we would just change the
name of the meeting. The original name
was "Health Effects of Direct Reuse," and
they changed the name to "Health Effects
of Direct and Indirect Reuse," because you
must address yourself to the same question,
and the water supply people and the waste-
water people both require answers.
Henry Ongerth is right. You still may
decide that you don't want to go into
direct reuse because of other complica-
tions. But whether you go into it or not,
you must answer all of the same questions
and you must have a technology to be able
to remove these things.
QUESTION: Mr. Gerald Berg, Methods
Development & Quality Assurance Research
Laboratory, NERC-EPA, Cincinnati, Ohio.
Lee, did I understand you correctly that
you believe you can now recover one virus
particle in a hundred gallons of water?
RESPONSE: Mr. McCabe. Yes.
QUESTION: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. Did you have a reliable
method for doing this?
RESPONSE: Mr. McCabe. Yes.
QUESTION: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. You believe you have
a reliable method for doing this?
RESPONSE: Mr. McCabe. Unless you are
going to ask me about hepatitis.
QUESTION: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. No. I'm not asking
you about hepatitis at all. I'm talking
about the overall problem. You believe
you have a reliable method for doing
this. Does this mean that you are now out
of the methods development business?
RESPONSE: Mr, McCabe. We calibrated a
method. We were able to calibrate it to
show that that's what its sensitivity
was. One per hundred gallons when you do
five hundred.
QUESTION: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. All right. I'll pass
over that last question. Let me ask you
this. Would you tell us how many dif-
ferent tap waters of how many different
qualities you tested in order to come to
that conclusion?
RESPONSE: Mr. McCabe. In my recollec-
tion, it was about twelve, Gerry.
COMMENT: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. Twelve waters, you've
based that conclusion on just twelve
waters. All right, I have one other ques-
tion.
93
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RESPONSE: Mr. McCabe. But the point I
was trying to make is that we've got a way
in which you could go if you want to make
drinking water out of wastewater.
COMMENT: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. But we're talking about
methods for testing and determining treat-
ment reliability and safety of water.
RESPONSE: Mr. McCabe. O.K. We've got
one, but it's got to be applied.
QUESTION: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. But you're basing the
assumption that you have a method on only
twelve different tests, twelve waters?
RESPONSE: Mr. McCabe. Yes. But some
of them were softening plants and some
were not.
QUESTION: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. Well, I think we have a
longer way to go than that. Let me ask
one more question. You tested seventy-
five different waters in different parts
of the country for viruses with this
system. Correct?
RESPONSE: Mr. McCabe. Well, we had to
go to some that were close because there
was a mileage problem with gasoline.
QUESTION: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. That's all right. I
have no objections. There were seventy^-
five plants tested, and you said that
along with these tests you ran a control
test in which you added a known amount of
virus. Would you tell us the efficiency
of recovery of virus from those controls,
not whether or not you got any but what
the efficiency was?
RESPONSE: Mr. McCabe. I think the ef-
ficiency was about sixty percent. But,
you see, that's why we have to check. To
tell you we got one in a hundred, we have
to run five hundred.
COMMENT: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. I understand that, Lee.
But as I recall, the efficiency varied
considerably from test to test and it
wasn't that high.
RESPONSE: Mr. McCabe. Well, it does
vary. Yes.
COMMENT: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. Considerably. What I
am saying is that I don't think we have
reliable methodology yet.
RESPONSE: Mr. McCabe. We have had a
long argument about whether the way to
proceed with this thing was percent re-
covery or "Yes" or "No." You mix up a
batch of a known level and let me know
when I can get them. That's what I have
been pushing them to do.
COMMENT: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. I don't really want to
push you up against the wall on this,
but it's impossible to test on a "Yes"
or "No" basis, because the more you put
in, the greater the likelihood of "Yes":
the less you put in, the greater the like-
lihood of "No."
RESPONSE: Mr. McCabe. Yes. But maybe
we have a batch that might be like drink-
ing water at its worst, and then tell me
where you can find them. That's the pre-
mise.
QUESTION: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. That's not really
"Yes" or "No." Then you are taking a
certain percentage of recovery. You are
setting it up to give you a certain per-
centage of recovery. That's not unreason-
able. But what I am asking you is: Do
you know what the percentage of recovery
of this is?
RESPONSE: Mr. McCabe. That's the pro-
blem. We can tell you whether there's
one in a hundred if you'll let us look at
five hundred gallons.
-------
COMMENT: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. What I'm saying to you
is I don't think you really can with any
degree of reliability. I don't think you
have done anywhere near enough tests on
nearly enough different kinds of waters.
RESPONSE: Mr. McCabe. That is why we
have written up as a tentative method in
Standard Methods so that a lot of people
can try. Maybe it only works in our hands.
COMMENT: Mr. Berg, Methods Development
& Quality Assurance Research Laboratory,
Cincinnati, Ohio. The Standard Methods is
another problem. But I don't think I
want to take time here for that now. We'll
take care of that in the workshops later
on.
COMMENT: Mr. Mark D. Sobsey, University
of North Carolina, Chapel Hill, North
Carolina. I disagree with the premise
that the methodology for viruses is that
good. The methodology that has been
developed and tested has been tested al-
most exclusively with enteroviruses. It
has not been tested with hepatitis Type A
or with the agents of viral gastroenteritis
because we can't work with those agents,
nor has the method been systematically
tested with adenoviruses and reoviruses
which are viruses of public health concern
in water. I think that additional work is
needed, and I agree with Gerry on this
point that additional work is needed on
methods development before we can say,
with some degree of assurance, that, in
fact, we have a reliable method and that
the reliability of the method has been
demonstrated with representatives of the
several different groups of enteric viruses
that are of public health concern.
RESPONSE: Mr. McCabe. We are doing
reovirus. The reovirus seem to die pretty
easily when they know they are going to
get chlorinated.
QUESTION: Mr. Richard Symuleski,
National Bureau of Standards, Washington,
B.C. In consideration of Mr. Shuval's
earlier comments on rapid monitoring of
microbiological contaminants in water, are
you doing any work on GC or MS for taxir-
nomic identification of pathogens?
RESPONSE: Mr. McCabe. I don't think
you need rapid monitoring.
QUESTION: Mr. Symuleski, National
Bureau of Standards, Washington, B.C.
Before you release a product?
RESPONSE: Mr. McCabe. I don't think
you are going to be quick enough to be
of much value to people. You are.better
off basing your acceptance on whether
that water is O.K. to go. If it has a
chlorine residual, a turbidity of so and
so, and a contact time of such and such,
you pump it out. You are not going to be
able to sit there and wait for the virus
results to see if water is fit to pump
to distribution.
QUESTION: Mr. Symuleski, National
Bureau of Standards, Washington, D.C.
In a situation where you have, let's say,
twenty-four or forty-eight-hour turn-
around time on your microbiological
parameters, wouldn't a higher degree of
reliability with rapid identification
give you the possibility?
RESPONSE: Mr. McCabe. No. I think
John ought to know his treatment train
well enough that he knows that if he treats
it this way, you're not going to have to
worry about it. Now in a research sense,
we are going to follow them. But then
when you actually go to applying it, I
don't think you are going to have real-
time monitoring except for those things
that we have spoken of as part of your
control of the treatment itself.
QUESTION: Mr. Symuleski, National
Bureau of Standards, Washington, D.C.
Then there is little interest in improving
microbiological test methods?
RESPONSE: Mr. McCabe. There is little
interest on my part. Yes.
COMMENT: Mr. Dryden, Sanitation Dis-
trict of L.A. County, Whittier, California,
Although I think there is perhaps more to
say to the question of the need for rapid
testing because I am in favor of more
rapid testing, that wasn't what I wanted
to speak to. I wanted to speak to your
opening remarks concerning the problem of
a utility proceeding with a water reuse
program in some direct sense. I would
like to point out that your concern is a
valid one. I don't think any single
95
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agency, whether it be a utility or a
health department, should be alone in try-
ing to make a decision as to whether a
particular reuse is or isn't acceptable
technologically, or publicly, or in any
other way. This is why the joint state-
ment of the AWWA and the WPCF advocated a
national, well-funded, interdisciplinary
study which would take into account all
of the various interests in water reuse:
the doctors, the AMA, the health people,
the universities, the water people, the
wastewater people. All of these have to
come together somehow and conceive of a
program. I figure that what we are doing
these three days is part of that: where
we conceive of a program that ultimately
will be carried out over a period of ten
years or fifteen years, whatever it is
going to. take to put the treatment chains
together and to do the biological, organ-
ic, and epidemiological studies so that
finally we get to the point where people
can agree that we either do or you don't
have a system which is viable. Such a
system must be proven so that people can
go ahead and use it without standing alone
while other people in the wings who didn't
participate take pot shots at them. I
think it is essential that it be done in
a unified way.
RESPONSE: Mr. McCabe. Thanks. That is
a good summary.
96
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EVALUATION OF THE HEALTH ASPECTS OF REUSING WASTEWATER FOR POTABLE PURPOSES IN ISRAEL
H.I. Shuval
Associate Professor of Environmental Health
Hebrew University -_ Hadassah Medical School
Jerusalem, Israel
ABSTRACT
Water supply in Israel for agricultural, industrial and municipal purposes is
currently utilizing over 90% of the country's potential water resources. By the year 1980
there will be an anticipated water deficit which will reach major proportions by the year
2000. In 1973 some 20% of the available municipal wastewater was utilized primarily for
agricultural purposes. The Dan Region Water Reclamation Project has been designed for
municipal and agricultural reuse of the wastewater of Tel-Aviv as well as six other neigh-
boring municipalities with an estimated future population of 1,700,000 and a wastewater
flow of 0.44 MCM/day (116 MGD). The reclaimed water will be directed to areas in the south
and will not be subject to multiple recycling. The present plans of the designers call for
biological and physical-chemical treatment, and recharge of effluent through sand dunes.
The reclaimed water will be pumped by a series of recovery wells which are designed to pro-
vide for a 400 day residence time in the aquifer. Since it is the intention of the planners
to provide reclaimed water with a quality suitable for all uses including potable purposest
further treatment of the water withdrawn from the aquifer by such processes as activated
carbon filtration and ozonization are being considered for the removal of refractory
organics. A preliminary program to evaluate the suitability of the reclaimed water for
human consumption has been initiated. The study includes chemical analysis for toxic or-
ganic and inorganic materials as well as subchronic and chronic feeding experiments of rats
with concentrates of the residual organics from the reclaimed water. Testing for the mi-
crobial safety of the water is also an essential part of the test program and includes de-
veloping rapid techniques for concentrating and detecting enteroviruses in water samples as
large as 400 liters (100 gals.). The methodology of the program to evaluate the health
effects of the reclaimed water is presented.
INTRODUCTION
Israel's Water Requirements
The severe limitations in natural
water resources have become a critical fact*-
tor in the development of Israel and has
led to an intensive search for alternative
sources of water including the reuse of
wastewater.
Israel is a small country with a
rapidly developing economy and a high rate
of population growth due primarily to an
open immigration policy. The population in
1974 reached three and one half million
and has more than quadrupled since the
country achieved its independence in 1948.
The area under irrigation increased more
than five fold during the same period.
Rainfall Breaches an annual average of 550
mm/yr (22"/yr) in the central coastal
plain and drops to 25mm/yr (l"/yr) at the
southern tip of the country.
Large scale water supply development
projects have tapped most of the countries
water resources and it has been estimated
that current water supplies for agricultural
industrial and municipal purposes are
97
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FIGURE N21
2400
WATER REQUIREMENTS VERSUS RESOURCES
AVAILABILITY IN ISRAEL
1000
1970
DESALINATION
-{EWATER TO BE
CLOSING" SOURCE
l
-------
utilizing over 90% of the country's po-
tential water reserves. The quantity of wa-
ter supplied in 1974 was 1,600 million cu-
bic meters per year (MCM/yr) (4xl05MG/yr).
It is estimated that the country's
population will reach well over four million
by the year 1985 at which time the total
water requirements will be 2,000 MCM/yr
(5xl05MG/yr) some 200 MCM/yr (5xl04MG/yr)
above the quantity estimated as being avail-
able from known ground and surface sources
(1) (Figure 1).
Intensive studies of alternative
sources of additional water supplies needed
to close the gap have been carried out in-
cluding desalination of sea and brackish
water, rainfall supplementation and waste-
water reuse.
Before the recent drastic increase in
the cost of energy, desalination of sea-
water was considered as an expensive al-
though inevitable alternative water source
which could at something under $1/1000 gals
meet growing municipal and industrial
needs. Current cost estimates for desalina-
tion of $4-5/1000 gals cast serious doubts
as to its economic feasibility except as an
absolute last resort.
Studies carried out in Israel on rain-
fall supplementation by cloud seeding have
produced promising results with statistic-
ally significant rainfall increases of
some 10% over a five year period. This pro-
gram has now become operational but will
not itself solve the severe water shortage
that is developing.
As early as 1956, the reuse of waste-
water was included in the National Water
Plan as an essential future water resource.
Early wastewater reuse efforts were direct-
ed mainly towards agricultural utilization
and by 1973 some 200 reuse projects were
utilizing 20-25% of the potentially avail-
able municipal wastewater (2). A number of
projects for reuse of wastewater by indust-
ry have also been successfully developed.
Israel's water planners now visualize
the rapid development of wastewater utiliza-
tion projects as an economically attractive
interum measure to close the gap in the
growing water supply deficit and thus post-
poning for as long as possible the large
investments and high operating costs asso-
ciated with sea water desalination.
However, even with the full develop-
ment of all planned wastewater utilization
projects by 1985 it must be recognized
that this source is limited and that event-
ually the only foreseeable solution to pro-
vide the additional water required will be
through large scale desalination of sea-
water. It is anticipated however that by
postponing such plants for 10-15 years,
technological progress made during the
interim will hopefully reduce the costs.
The five year national plan for water
resources development in Israel envisages
the implementation by 1980 of several major
wastewater reclamation projects, of these
the Dan Region Water Reclamation Project
will be the largest and will contribute
.247 MCM/day (65 MGD) growing to 0.44
MCM/day (116 MGD) by the year 2000 (1).
This project has as its goal the production
of a water suitable in quality to meet all
requirements including potable purposes.
Reuse of wastewater as compared to
seawater desalination can be seen as a re-
latively low energy demanding alternative
water source. Simply from the point of
solids removal requirements it can be
pointed out that only about 1000 ppm of
solids must be removed from wastewater
while 30,000 ppm must be removed from sea-
water to meet equivalent drinking water
standards. However, there are many unique
problems that must be dealt with in wastes
water renovation including the inactivation
of pathogenic microorganisms and removal of
refractory organics which may be toxic at
very low concentrations. The ability of
advanced wastewater treatment technology to
meet these problems will be the real test
as to the competitiveness of wastewater
reuse.
The remainder of this paper will be
devoted to questions associated with
evaluating the health aspects of reusing
wastewater from the Dan Region Water Re-
clamation Project for potable purposes.
DAN REGION WASTEWATER UTILIZATION PROJECT
The city of Tel Aviv, Israel's major
metropolitan center and six neighboring
municipalities have joined together to
form the Dan Region Sewerage Association
to solve their common wastewater disposal
problems. Two other townships are also
planning to join in the near future.
99
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The region's main mode of wastewater
disposal is through outfall sewers to the
sea leading to serious pollution of nearby
Tel Aviv bathing beaches (3).
The Dan Region Wastewater Reclamation
Project was initiated in the early 1960's
by Tahal-Water Planning for Israel with the
aim of solving the problem of beach pollu-
tion and of recycling the large volumes of
wastewater to the national water system (4)
(5). In 1974 the total population included
in the region was about 1,000,000 persons.
The estimated population for 1985 is
1,300,000 reaching about 1,700,000 in the
year 2000. Total mean water consumption of
the region in 1974 was .3 MCM/day (75 MGD).
Estimated water consumption for 1985 is
.41 MCM/day (103 MGD) reaching .55 MCM/day
(137 MGD) by the year 2000 (1).
Both due to the recent drastic in-
creases in the costs of energy which has
made seawater desalination an impractical
alternative water source at this time, and
the urgent need to reduce the pollution of
the Tel Aviv beaches, the Dan Region Project
has been given the highest priority in the
national water resources development pro-
gram. The project is now in an advanced
stage of design and construction.
The Dan Region Project includes the
construction of major intercepting sewers
to convey the wastewater from all the towns
in the region to the treatment site in the
sand dune area along the coast south of Tel
Aviv. There, the wastewater will be pro-
cessed by biological and chemical treatment
processes prior to pumping the effluent to
recharge basins located on the sand dunes.
The water will be pumped from the aquifer
by a series of recovery wells located
several hundred meters away from the re-
charge basins. The recovery wells have been
designed to provide for a residence time of
some 400 days in the aquifer and for a de-
gree of dilution, with the ground water.
The reclaimed water extracted from the
acquifer will then receive final polishing
treatment and further dilution depending
upon its intended use. The reclaimed water
will be conveyed mainly to the Negev area
south of the Dan Region and will therefore
not be subject to multiple recycling. This
will avoid the problem of build up of
dissolved minerals and refractory organics
with its many associated complications.
Since it is one of the goals of the
project to produce water of a quality suit-
able for domestic consumption, considera-
tion must be given to additional treat-
ment to remove potentially toxic residual
organics and totally inactivate all patho-
genic bacteria and viruses. Filtration in
activated carbon columns and ozonization
are possible final treatment stages to be
provided for the reclaimed water intended
for domestic use.
Despite the advanced stage of the
project the designers have as yet made no
final plans for the treatment of the re-
claimed water for purposes of domestic con-
sumption. The results of studies to
evaluate the health aspects of reusing the
effluent for potable purposes which have
recently been initiated at the Hebrew Uni-
versity of Jerusalem will provide valuable
guidance in determining the degree and
form of additional treatment that will be
required.
One of the questions facing the de-
signers is whether to provide additional
treatment for all the reclaimed water or
only for the portion of it directed for
municipal use. As presently designed the
national water system supplying-."the south
of the country is a fully integrated one
which serves both agricultural and munici-
pal consumers with the same quality water,
all of which currently meets drinking water
standards. The Dan Region Project's initial
plans called for supplying reclaimed water
directly to this system. This would dictate
that all such water meet standards required
for potable use. However, over 80% of the
water is used in agriculture which could
accept water of a lower chemical standard,
but which has been adequately treated as
far as enteric bacteria and viruses are con-
cerned. The production of well disinfected
wastewater for unrestricted agricultural
use would be far less complicated and more
economical than producing water for potable
use.
The designers are presently consider-
ing the possibility of developing separate
water supply system for utilizing reclaimed
water from the Dan Project so that the major
part could be used for agricultural and in-
dustrial purposes and only a portion, which
would receive additional treatment, would be
used for municipal and domestic purposes.
100
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DAN SEWAGE RECLAMATION PROJECT
SECOND STAGE (100 MCM/YEAR
SCHEMATIC LAYOUT
FIGURE N22
TO PROPOSED
TREATMENT
PL
.RAW WASTEWATER
I FROM MAIN t«4 COLLECTOR
•TO XISTINO PONOS
! SCRE
PUMP STATION
! W-i
AERATION
TANK
101
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The costs involved in developing such a se-
parate supply system may be appreciable
however. Another possible alternative is
to use all of the reclaimed water for agri-
cultural or industrial purposes, if it de-
velops that meeting drinking water criteria
makes the project economically unfeasible.
The project has been planned for de-
velopment in two stages and has been des-
cribed as follows by Amir and Idelovitch
of Tahal (1):
First Stage
The first stage now in operation has
a load of .041 MCM/day C10.3 MGD) and
serves the southern suburbs of Tel Aviv as
well as three neighboring towns. The
treatment' as now developed includes: bio-
logical purification in recirculated facult-
ative oxidation ponds having an area of 120
hectares; chemical treatment by excess lime
precipitation; ammonia stripping in open
ponds; effluent stabilization in ponds and
lime sludge disposal. The biological treat-
ment ponds have been operated since 1970
while the chemical treatment and recharge of
effluent is planned for the early part of
1975. A series of observation wells have
been placed at varying distances between the
ponds, recharge basins, and recovery wells
so that the effects of percolation from the
ponds and recharge basins on the quality of
the water in the aquifer can be determined
at various stages prior to the arrival of
the recharged water at the recovery wells.
Second Stage
The second stage will have a capacity
of .27 MCM/day (68.5 MGD) and will serve
the whole area of the Dan Region. This
stage is now in an advanced stage of plan-
ning (see Figure 2). The treatment in-
cludes: advanced biological purification
by a modified low-rate activated sludge
process which will provide for nitrifica-
tion and denitrification, (the treatment
in oxidation ponds will be partially aban-
doned in the second stage due to the large
land area required); in-plant chemical pre-
cipitation; post aeration and disinfection
of the effluent; and excess sludge disposal
by means of a long sea outfall which will
assure suitable dilution, dispersion and
bacterial decay before reaching the shore
line. Some existing ponds from the first
stage will be integrated into the operation
of the second stage treatment plant in order
to reduce peak loads reaching the main
plant, thus allowing for savings in capital
and operating costs.
In the early stages of evaluating the
quality of the reclaimed water from the
Dan Project it becomes apparent that the
concentration of nitrates would be several
times greater than that recommended for
drinking water. The facilities for excess
lime precipitation and ammonia stripping in
open ponds in the first stage and the ni-
trification/denitrification capacity of the
low-rate activated sludge process in the
second stage were designed specifically to
TABLE NO. 1: DAN SEWAGE RECLAMATION PROJECT - SECOND STAGE
VALUE OF MAJOR PARAMETERS IN WASTEWATER AND EFFLUENT (in mff/1)
BOD, mg/1
COD
SS
Total N
NH^/N + Org N
(N03 + N02) N
Phosphates P
Chlorides
Dissolved Oxygen
Coliform per 100 ml
Raw wastewater
300-700
600-1600
350-500
70-100
40-70
0.5-1
10-20
150-350
10?-109
Plant effluent
10-15
60-120
10-20
10
8
2
1.5
150-350
4
10-500
102
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meet this problem. It is anticipated that
the total nitrogen of the effluent before
recharge will be under 10 ppm and that the
reclaimed water will not deviate from
accepted standards for nitrates.
The designers report that the anti-
cipated main chemical characteristics of
raw wastewater, the secondary effluent, and
tertiary effluent prior to infiltration
into the aquifer will be as shown in Table
1 (1). They also anticipate further im-
provement of the physical chemical and mi-
crobiological quality as a result of the
slow sand filtration in the recharge basins
and long period of residence, further fil-
tration and dilution that occurs in the
acqiiifer prior to recovery. They estimate
that the recovered water, after further dis-
infection and dilution with good quality
ground water will "met prevailing standards
for drinking water quality"(1). However,
here it must be stated that the W.H.O. has
reported that meeting conventional standards
for drinking water cannot be considered as
adequate in the case of reclaimed waste-
water for potable use (6). The health re-
quirements involved should be much stricter
since the water source under consideration
may contain many of the toxic inorganic and
organic chemicals found in municipal and in-
dustrial wastewater as well as their little
studied breakdown products.
Estimated Costs
The designers estimated cost of pro-
ducing the tertiary effluent in the second
stage is ^70-^90/1000 gal while the addition-
al cost of recharge and recovery is estimat-
ed at $.20->30/1000 gals). The total cost of
reclamation without the costs for additional
treatment that will most likely be required
to remove potentially toxic residual or-
ganics is thus estimated at $90-1.20/1000
gals (1). It can be assumed that activated
carbon treatment and ozonization will be re-
quired for that portion of the reclaimed
water which will be supplied for domestic
consumption, thus additional costs in the
range of $0.15-0.25/1000 gals will have to be
included. Although this is indeed costly,
the only alternative water source for cost
comparison purposes is desalinated seawater
which is now estimated to cost about
$4-5/1000 gals.
EVALUATION OF HEALTH EFFECTS OF RECLAIMED
WASTEWATER - GENERAL APPROACH
The approach to evaluating the
health effects of reusing wastewater for
potable purposes in Israel recommended by
the author to the health and water autho-
rities in Israel has been fully detailed in
a previous paper (7) and follows the ge-
neral approached presented in the W.H.O.
report on health safeguards in the reuse of
effluents of 1973 (6). This approach has
been further refined in the report of the
International Working Meeting on the Health
Effects Relating to Direct and Indirect
Reuse of Wastewater for Human Consumption
(8) held in Amsterdam in January 1975.
This approach is based on the pre-
mise that conventional drinking water
standards are not considered as providing
an adequate basis for the health evaluation
of reclaimed wastewater to be used for po-
table purposes. These standards do not
usually include maximum allowable concentra-
tions for the hundreds of potentially toxic
organics which can appear in urban and in-
dustrial wastewater. Also, such standards
cannot as yet cope with the problem of the
little known breakdown products resulting
from biological degradation or from
chemical reactions that occur as a result
of treatment. The formation of carcino-
genic organohalides by chlorination of
water contaminated with organics is just
one illustration of the complexity of the
problem (9). Recent surveys of organics in
polluted river water, wastewater effluent
and finished drinking water carried out in
Europe and the United States have detected
as many as 1000 different organic compounds.
Many of these have known toxic effects
while little or nothing is known about the
possible chronic effects of hundreds of
these compounds (8). Although it is hoped
that one day there will be adequate toxi-
cological data to allow for the establish-
ment of specific standards for each one of
the hundreds of chemicals that could appear
at times in renovated water, this is felt
to be an impractical goal for the near
future.
Therefore, the Amsterdam report (8)
recommended that an essential precondition
for any reuse of wastewater for domestic
consumption is the control of industrial
wastes to the maximum degree so as to re-
move at source as many potentially toxic
103
-------
chemicals as possible. They also recommend-
ed ". . .that to the extent that it is feas-
ible, industrial effluents should be total-
ly diverted from the reuse system."
The report further recommended "that
at this stage with the tremendous gap in
knowledge concerning the toxic effects
associated with organic components in reno-
vated water, the most prudent policy would
be to provide for the optimal removal of
total organic carbon to the lowest feasible
level." They set as a tentative goal "less
than 5 ppm of TOC".
Our approach, and that recommended by
the W.H.O. recognizes that it is not poss-
ible to fully evaluate the possible toxi-
cological effects of renovated water based
on a study of specific chemical constituents.
The W.H.O. therefore recommends (6) "that
the complete and proper toxicological evalu-
ation should be made using the actual finish-
ed water intended for human consumption
with;its real mixture of residual chemicals
(and concentrates of them) remaining after
treatment. Long term feeding experiments
with more than one species of experimental
animals may be required as well as other
toxicological evaluation tests."
The first essential step in carrying
out the toxicological evaluation of the real
mixture of residual chemicals is to develop
an appropriate technique for concentrating
these organics from the final effluent
planned for reuse. It is essential to obtain
concentrates of these chemicals 10-100 times
those found in the renovated water itself
for proper chronic toxicity studies with
animals. Standard procedures in chronic ex-
posure experiments require feeding animals
with concentrations many fold greater than
proposed for actual use. This safety factor
is essential in order to detect any detri-
mental effects that may appear only in
particularly susceptible elements in the
normal population which usually includes the
aged, the infirm, infants and pregnant women.
It is also not possible to expose animal
colonies equivalent in size to the actual
population groups of hundreds of thousands
that may be exposed to renovated wastewater.
For these reasons, reliable methods for con-
centrating the organics in wastewater are re-
quired. These methods must not lead to a
change in chemical composition or effect the
integrity of the organic components while
avoiding the loss of essential fractions.
It has been estimated that for a two
year chronic study with 300 rats, which we
are planning, it will be necessary to pro-
cess some 500 cubic meters of water if a
concentration factor of 100 is to be achiev-
ed. We have initiated preliminary studies
for concentrating organics to meet the
above criteria using adsorption/desorption
and ultrafiltration membrane processes
but to date find a significant loss of
organics takes place. The E.P.A. Water
Supply Research Laboratory in Cincinnati
has made considerable progress toward solv-
ing these problems. Our planned testing
program of reclaimed water from the Dan
Region Project includes sub chronic (90
day) and chronic (2 years) tests with rats
with various concentrates up to 100 times.
We will also process the water with acti-
vated carbon alone and in combination with
ozonation to achieve the lowest feasible
level of total organic carbon. Tests for
carcinogenicity, teratogenicity and muta-
genicity will be made as well as tests on
fertility. A 3-5 year period is required
for such a program of studies.
Preliminary tests of water drawn from
an observation well 50 meters from the
existing oxidation ponds indicate a TOC of
10 in the ground water which, according to
its salinity appears to be about 75% waste-
water effluent and 25% groundwater. The
pond effluent itself has a TOC of 40 ppm.
These very tentative preliminary findings
indicate that some of the residual organics
do indeed pass through the sandy aquifer. If
these findings hold true for the final pro-
ject working under somewhat more favorable
conditions, they may indicate that addition-
al treatment to remove organics will be re-
quired. Another indication of this is the
concentration of A.B.S. in the reclaimed
water of 5 ppm as compared to 13.6 ppm in
the pond effluent. Hard detergents are still
used in Israel.
MICROBIAL QUALITY
One of the earliest concerns in waste-
water reuse for potable purposes has been
the risk of pathogenic bacteria and viruses
passing through the system. There has been
particular concern about viruses since it
has been demonstrated that they are under
certain conditions many times more resistent
than bacteria to natural inactivation and
various water and wastewater treatment pro-
cesses. Another reason for the special con-
cern about the virus risk has been the
104
-------
evidence that very small numbers of viruses
can be infectious to man.
In order to assure the safety of re-
claimed water for potable use it is essen-
tial to develop reliable monitoring methods
to check for the presence of viruses in
very large volumes of water. Various au-
thorities have suggested that anywhere
between 100-1000 gals of water need be
tested for viruses in renovated water. A
number of potential methods for carrying
out such tests are under development (10).
The planners of the Dan Project are fully
aware of the need to monitor the reclaimed
water for bacteria and viral pollution and
have initiated such programs.
We are currently working on evaluat-
ing the effectiveness of various virus mo-
nitoring techniques in order to select the
most effective one for large volumes of re-
novated water.
A prudent monitoring policy should
provide for completion of microbial testing
including virus assay before supplying the
water to the public. Dr. E. Katzenelson of
our laboratory is presently developing a
very rapid virus monitoring technique using
fluorescent antibodies which can provide a
qualitative answer in .19 hours and a quanti-
tative assay in 24 hours. Such a technique
will be particularly vital in monitoring
reuse projects which allow for only limited
hold-up time of the final effluent.
Monitoring
Assuming that after a full toxicolo-
gical evaluation of the final treatment
train the reclaimed water is found to be
acceptable for human consumption, it will
still be necessary to establish a special
monitoring program to assure that water of
a consistantly safe quality will be supplied
to the public.
In the case of the Dan Region Project
this is facilitated by the series of ob-
servation wells located between the recharge
basins and the recovery wells. It will be
possible to withdraw water at regular inter-
vals and to determine any changes in
quality of the reclaimed water months before
it reaches the recovery wells. In addition
to bacteriological and virological tests
and analysis for known inorganic and organic
toxic chemicals, it will be essential to de-
velop rapid toxicological bioassays. A
number of promising methods using bacteria,
cell cultures and fish are under develop-
ment and may become available to meet this
method.
The approach to monitoring reclaimed
wastewater for potable purposes must be
stricter than that currently applied to
drinking water and should require the
completion of all microbiological, chemical
and toxicological assays prior to the re-
lease of the water to the public. In the
case of the Dan Project, this is quite
feasible, but for projects that do not in-
clude long term storage in the ground
water special holding tank facilities
would be required.
Conclusion
Wastewater reuse has received a very
high priority in the national water re-
sources development plans of Israel due to
the severe shortage of water facing the
country. The Dan Region Water Reclamation
Project in aiming to supply renovated water
for potable consumption will have to meet
the most rigorous tests to assure that the
final product will have np detrimental
effects on human health. Detailed chemical
analysis and a full toxicological evalua-
tion of possible chronic effects is being
initiated as well as a rigorous bacterial
and viral testing program. The adequacy of
the final treatment train in removing path-
ogens and potentially toxic organics is yet
to be determined. However, the Dan Project
has a valuable built-in safety factor in
its use of recharge and long term under-
ground storage which facilitate stringent
monitoring and control programs.
The results of these vital studies
will enable the health authorities to de-
termine the suitability of the reclaimed
water for potable use.
Acknowledgement:
We wish to thank Mr. Y. Amir and
Mr. E. Idelovltch of Tahal-Consulting
Engineers Ltd., Tel Aviv for the use of
figures 1 and 2 and the other valuable data
on the Dan Region Water Reclamation Project.
105
-------
REFERENCES
1. Amir Y. and Idelovitch E. "Reuse of
Municipal Wastewater - Dan Region
Project". Proceedings UN Expert Meeting
on Efficiency in the Use and Reuse of
Water - Tel Aviv November 1974 (Tahal
Consulting Engineers Ltd., Tel Aviv).
2. Finemesser A. "Survey of Agricultural
Reuse of Wastewater in Israel" - Israel
Water Commission (1973).
3. Shuval, H.I., Cohen M., and Yoshpe-
Purer Y. "The Dispersion of Bacterial
Pollution Along the Tel Aviv Shore"
Rev. Intern. Oceanogr. Med. 9:197-121
(1968).
4. Amramy,, A. "Waste Treatment for Ground-
water Recharge" in Advances in Water
Pollution Research Vol. 2:147-168,
Pergamon Press Oxford (1965).
5. Caspi, B. Zohar, Y. and Saliternik C.
"Water Reuse in Israel in Proc. Int.
Symp. on Conservation of Water by Re-
use" American Chem. Soc. (1966).
6. W.H.O. "Reuse of Effluents: Methods of
Wastewater Treatment and Health Safe-
guards" - WHO Technical Report Series,
No. 514, Geneva (1973).
7. Shuval H.I. and Gruener N. "Health Con-
siderations in Renovating Wastewater for
Domestic Use" Env. Sci. and Tech. 7:600-
604 (1973).
8. WHO International Reference Center for
Community Water Supply. "Report of the
International Working Meeting on Health
Effects Relating to Direct and Indirect
Reuse of Wastewater for Human Consumpt-
ion" Amsterdam, January 1975 (in press).
9. Bellar T.A., Lichtenberg, J.J., and
Kroner R.C. "The Occurrence of Organo-
halides in Chlorinated Drinking Water."
Jour. A.W.W.A. 12:703-706 (1974).
10. Shuval H.I. and Katzenelson E. "The De-
tection of Enteric Viruses in the Water
Environment" in Water Pollution Micro-
biology ed. R. Mitchell, John Wiley,
New York (1972).
106
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APPENDIX
RESEARCH NEEDS: EVALUATION OF THE HEALTH ASPECTS OF REUSING WASTEWATER FOR POTABLE PURPOSES
Prepared by: H.I. Shuval
A. General Recommendations
1. Since individual municipalities, regions
or even national reuse projects in smaller
countries will not normally be in a posi-
tion to carry out the full spectrum of
required studies to evaluate the health
aspects of reusing wastewater for potable
purposes and since the results of such
studies will be of universal value, it is
essential that major research support be
provided by the Federal Government in the
United States, research foundations and
the United Nations agencies.
2. Such studies should be carried out in
an international coordinated program so
that the maximum amount of information be
mustered from varying sources to meet the
vital research needs of all bodies con-
cerned .
3. An international scientific coordinat-
ing group should be established to further
the above objectives.
B. Specific Recommendations
1. Methods must be developed to effec-
tively concentrate organics in large
volumes of wastewater effluent so as to
provide material for chronic animal ex-
posure tests. -Concentrates of at least
100 times should be obtainable, which
maintain the integrity of the chemical
components, do not change the relative
concentrations and do not lead to the loss
of essential fractions.
2. Refined screening assays for categories
of organic compounds of potential toxic
importance should be developed to replace
gross tests for organics such as C.O.D.,
C.C.E. and T.O.C.
3. Reliable tests for the rapid detection
of low concentrations of viruses in large
107
volumes of water (as much as 1000 gals)
should be developed and standardized.
4. Chronic toxicological studies should
be carried out on as great a number as
possible of the organic refractories of
suspected toxic importance detected in
wastewater streams so as to provide a
rational basis for evaluating the risks
involved in the presence of such compounds
in reclaimed water for potable use. Where
possible, maximum allowable concentrations
for drinking water should be established.
5. Rapid bioassay methods should be de-
veloped to allow for the routine toxicolo-
gical monitoring of reclaimed wastewater
destined for potable use.
6. Retrospective and prospective epidemic-
logical studies should be carried out on
population groups exposed to heavy polluted
surface waters supplies (in direct waste-
water reuse) so as to determine if there
are detectible detrimental health effects.
These studies should be international in
character but should follow carefully pre-
determined research criteria so as to
assure comparability.
7. A carefully designed protocol for
chronic animal exposure experiments with
reclaimed wastewater (and concentrates of
the same water) should be prepared and
pretested which could serve as a guide for
the various testing programs for different
wastewater reuse projects. Then a coord-
inated series of programs should be ini-
tiated with all results being provided to
the parties concerned. Various advanced
wastewater treatment systems for water
reclamation could thus be evaluated on a
comparable basis.
U.S EPA Headquarters LiD;.-..
Mail code 3404T
1200 Pennsylvania Avenue ••
Washington, DC 2U4bvj
202-566-0556
-------
DISCUSSION
QUESTION: Mr. Charles W. Lee, Washing-
ton University Hedical School, St. Louis,
Missouri. I am interested in the vasodi-
lation effect that you observed in feeding
nitrates to the rats. Would you care to
comment as to what chemical form of nitrate
you actually gave these animals? And was
there a corresponding blood pressure lower-
ing effect that was recorded with the vaso-
dilation?
RESPONSE: Prof. Shuval. We administered
both sodium nitrite and sodium nitrate in
drinking water to rats over an 18 month
period and the effect of dilation of
heart blood vessels was detected for both
chemicals. We did not check the blood
pressure of the rats although I agree that
it is an interesting question worth look-
ing into. Although the toxicological im-
portance to humans in this finding is not
yet clear, it does add further weight to
the case against relaxing the nitrate
standards in drinking water until we know
more about the possible chronic effects
on man. We have submitted our full report
on this to the EPA.
QUESTION: Mr. Jack Glennon, U.S. Army
Medical Research Development Command,
Washington, D.C. Two of your comments
sort of got me a little concerned and also
surprised. I anticipated that you would
probably get a large loss of water due to
infiltration and evaporation in the oxi-
dation pond process. Do you have any
plans in mind to close the loop for the
direct recycle: in other words, there may
be a higher return for the water?
The second question. I was a little
surprised to see your plant dispose of
the sludge at sea with the option to at
least stabilize the sand-dune areas and
this sort of thing. Are there any plans
to turn that around?
RESPONSE: Prof. Shuval. As to the first
question of water loss, yes, there will
be some water loss due to evaporation and
infiltration. The replacement of ponds
by activated sludge in the second stage
will reduce evaporation; but we do need
long-term storage facilities and balancing
of the flow, and feel that groundwater
recharge is worth the price.
The Dan Project includes a series of
monitoring wells from the recharge point
to the pickup point whereby we can monitor
the quality of the water continuously
months before we have to use it. We feel
that that type of protective buffer is
well worth the investment.
As for sludge disposal, I am not in a
position to debate it. I am not particu-
larly in favor of sea disposal, but that
is what the designers are proposing. I
would say that there are other alternatives,
such as land disposal and sludge utiliza-
tion.
108
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National
HEALTH ASPECTS OP REUSING ¥ASTE¥ATER FOR POTABLE PURPOSES -
SOUTH AFRICAN EXPERIENCE
E.M. Nupen and ¥.H.J. Hattingh
Institute for ¥ater Research of the Council for Scientific and Industrial Research
P.O. Box 395, Pretoria 0001, Republic of South Africa
ABSTRACT
In studies on the health affects of the reuse of municipal wastewaters, drinking water
supplies and their sources were analysed for a wide range of chemical and microbiological
quality parameters. Studies were also done to determine possible health effects not
covered by these parameters. Potable waters derived from advanced reclamation processes
were also included. Results presented are those obtained during the first two years of a
ten year study. All the drinking water supplies tested conformed to international quality
criteria. Organic material extracted from drinking waters had no adverse effects on the
health of laboratory animals. The quality of reclaimed drinking water was better than
that of many supplies derived from surface sources. Consumption of reclaimed water had no
detectable effect on the incidence or epidemiology of diseases in the community. Contem-
plated studies aimed at analysing drinking waters in greater detail for possible adverse
health effects and current research needs are discussed.
INTRODUCTION
Southern Africa will not have enough
fresh water resources by the year 2000. Al-
ready one city in the area has had to resort
to the reclamation of municipal wastewater
to augment its potable supplies. Similar
reclamation systems are foreseen in many
other developing areas where population
growth will outstrip water supply. More
than 60 per cent of the water supplied to a
city becomes wastewater which is treated in
sewage purification plants before being dis-
charged into natural drainage systems.
There is therefore a rapid, ever-increasing
volume of treated sewage effluent polluting
the natural water resources. Simultaneousljf
the complexity and variety of the pollutants
present in these -effluents are also increas -
ing, as new chemical products become availa-
ble to meet the present-day technological
development.
Pollutants dangerous to public health in
municipal wastewater, range from chemicals
such as carcinogens and heavy metals, to
pathogenic microorganisms. There is a
paucity of knowledge of the occurrence of
many of these pollutants in surface waters,
sewage and sewage works effluent and of
their possible effects upon man. Long-term
consumption of water containing pollutants,
might produce chronic or perhaps acute
disease with resultant grave economic im-
plications. Existing water purification
plants may not be equipped to meet these
rapidly changing conditions. On the other
hand, the efficiency of reclamation plants
treating municipal wastewaters for reuse,
has been intensively studied for the
successful removal of many pollutants (l-lO),
yet the possible effects of the introduction
of such reclaimed wastewater on the health
of the receiving community must be assessed.
Much time and thought have gone into
the consideration of these questions. Can
the impact of the introduction of reclaimed
water be measured in terms of epidemiologi-
cal patterns? How great are the health
hazards involved? What about infectious
hepatitis - carcinogens - shock loads of
toxic wastes - heavy metals? In our search
for answers, we found that these same
questions applied to all drinking water
supplies.
109
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Epidemiologies! studies have proved un-
reliable for the assessment of many health
aspects related to drinking waters because
of difficulties in data collection, and as
it is only when gross pollution occurs,
that the effect of toxic or disease pro-
ducing pollutants can be measured by their
obvious reaction in the community; micro-
pollutants responsible for long-term health
effects or the production of infection
without obvious disease patterns are not
detected. Therefore an in-depth study of
the quality of water supplies to a communi-
ty, will give the greatest information
regarding the safety of the health of that
community in relation to its drinking water
supply.
A programme was therefore evolved and
is being conducted, to determine the health
aspects of reclaimed wastewaters, by the
collection of information on the type and
quality of the constituents in municipal
wastewaters, reclaimed wastewaters and other
waters, using chemical, microbiological,
cytotoxicological, bio-assaying, immunolo-
gical and epidemiological techniques. This
data forms a base line on which variations
in the quality of reclaimed and other waters
are measured, now and in the future, so
that the health of the receiving communities
may be protected.
SURVEILLANCE PROGRAMME
A ten year water quality surveillance
programme commenced in 1973 in two areas of
Southern Africa. In area A, reclaimed
municipal wastewater periodically augments
the drinking waters obtained from a series
of boreholes and from three dams. The
municipal wastewater which is reused is of
purely domestic origin.
In area B, a treated river water, which
supplies the largest population density in
the country, is augmented by a treated dam
water, a chlorinated spring water, a bore-
hole water and chlorinated and unchlorinated
fountain waters. The river water before
treatment receives effluent from several
sewage purification plants and surface run-
off from a densely populated and industrial-
ised area. An experimental 4-5 MB/d
reclamation plant, which treats mixed
domestic and industrial wastewaters, is also
situated in this area.
The safety of the waters in these two
areas for potable use will be evaluated by
the interpretation of data obtained from:
(a) The chemical and microbiological
qualities of the waters.
(b) The use of cell culture systems to test
the water for possible cytotoxicity.
(c) An investigation into the possibility
of the spread of R+ bacteria by
polluted waters.
(d) The determination of long-term effects
of possible pollutants by means of the
bio-assaying of different waters using
experimental animals such as rats, mice,
fish, dogs and primates.
(e) A limited epidemiological survey in
area A.
(f) Virus and serum banks of specimens
collected in (a) and (e) which may be
used for retrospective immunological
studies, if necessary.
Chemical and microbiological
analytical procedures
Viruses which may be present in the
water environment are well documented (9,
11-13). It is possible that other viral
enteric pathogens such as those recently
isolated by Bishop et al,. (l4), Paver
.et. al. (15) and Kapikian (l6) may also be
transmissible by water. For the purpose of
this study, poliovirus strains, coxsackie
viruses which can be isolated in tissue
cultures, enterovir-uses and adenoviruses
(over 100 strains in all) are used to
determine virus pollution.
Evaluations for total vegetative bacte-
ria, coliform organisms, presumptive and
confirmed E.. coli I, Ps. aeruginosa. 01.
perfringens and Staphylococcus aureus and
viruses were done as previously described
(l,2,17-19). Small numbers of parasite ova
(Ascaris spp., Taenia spp., Trichuris
trichuria and various species of hookworm)
were concentrated from large volumes of
water by the same ultrafiltration method
described for viruses.
Chemical evaluations for parameters
shown in Table 1 were based on published
methods (20) many of which have been auto-
mated. The inorganic constituents are well
defined (see Table 2) but analytical techni-
ques for the characterisation and evaluation
of organic materials are mostly undeveloped.
Such material exists in small concentrations
in water (about 1 to 5 mg C/C). Before this
material can be identified, it must first
be concentrated and extracted without any
110
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TABLE 1- CHEMICAL QUALITY OF SOME OF TEE TREATED BRINKIltC WATERS. AREA A.
-n
Conductivity (uaho/cm) |
1
!
i
Total aUellnitv (CaCOj)
Chemical ozrgen demand
NBAS (Manoxol OT)
HBjl (»)
Ori^ic-N __(•) _
KO.-» „_(») _
»o!-» (»)
Orto-P (P)
Orgnnlo-P (p)
Inorganio-P (C)
Oraanie-C (c)
Sodinm (Ka)
Fotamaium (K)
.Calcium (Ca)
Magnesium (Kg)
Chloride (Cl~)
Sulphate (soj')
fluoride !F")
Silica (Si)
Silver (Af)
Arslne (Aa)
Barium (Ba)
Cyanide (OB")
Aluminium (Al)
Boron (B)
Beryllium (B.)
Cadmium (Cd)
Cobalt (Co)
Chrome (Cr)
Cojper (Cu)
Bereury (He)
Iron (Fe)
Jtauameee (an)
ncttl (Hi)
Lead (pb)
Strontium (5r)
Zinc (Zn)
Selanlum fs,)
Treated dam water in
1971
Kin/max.
7^2-8,4^
230-330
69-154
9-54
<0, 1-0,7
0-0,5
0-1,1
0-0,5
0,2-1,0
0-0,2
0-0,5
-
1-28
11-24
5-8
36-49
4-6
13-33
26-60
<0,1-0,3
0,4-3,0
-
-
-
<1 00-100
<100-200
<5
<5
<25
<25
8-75
_
<25-151
<25-30
<25-40
6-122
59-144
<25-53
-
72
Aver.
_
230
92
19
0,2
0,2
0,4
0,1
0,4
0,1
0,2
-
8
17
7
42
5
24
38
0,2
0,9
-
<50
-
100
100
<5
<5
<25
<25
23
_
67
<25
<25
27
92
25
-
1973
Kin/max.
Zt$&t£-
323-358
58-109
2M3
0,2-0,7
<0,2-0,4
0,5-1,2
<0,1
<0,2-0,8
<0,2
<0,2-0,7
-
20-24
16-17
9-11
33-44
5
18-30
27-63
0,3-0,4
0,2-0,5
-
<50
-
<100-1300
<100
<50
<5
<25
<25
<25 .
<25
<25
<25
<25
<2 5-140
<25
-
Aver.
337
83
37
"oTJ"
0,3
0,8
«,1
0,5
<0,2
0,4
-
21
17
10
37
5
23
42
0,3
0.3
-
<50
-
867
<100
<50
<5
<25
<25
<25
<25
<25
<25
<25
60
<25
-
19V
Hia/max.
7,7-9, P
223-372
64-78
19-35
<0, 1-0,5
0,3-0,4
0,4-1,0
<0,1
0,6-1,1
<0,2
<0, 2-0,4
-
6-15
12-23
5-6
30-51
3-4
18-20
28-77
0,1-0,3
1.5-2.0
-
<50
123-627
<100
<50
<5
<25
,<25
<25
26-49
<25
<25
<25
60-150
27-42
-
Aver.
_
340
72
30
0,3
0,3
0,8
<0,1
0,8
<0,2
0,3
-
' 11
18
5 ^
37
3
19
44
0,2
2.0
_
<50
-
377
<100
<50
<5
<25
<25
<25
•-
38
<25 .
<25
<25 J
108
35
-
Borehole water I
1973
Kin/max.
7.8-8.3
270-662
83-220
18-27
<0, 1-1,0
<0,2-0,3
0,6-1,0
<0,1
0,2-0,9
.<0,2
<0,2-1,9
-
13-28
5-25
6-9
42-68
6-27
4-8
11-103
0,2-0,4
3-35
-
2>o
-
<100
<100
<50
•=5
<25
<25
<25
<25
S5.
<25
80-130
<25-100
-
Aver.
_
521
174
22
0,4
0,2
0,5
<0,1
<0,2
1.1
-
24
18
8
56
20
6
51
0,3
20
-
-
<50
-
<100
<100
<50
<5
<25
<25
<25
<25
<25
<25
<25
104
64
-
1974
Bin/max.
~&*Q=&t2
^629-672
178-248
24-147
<0,1-0,6
0,2-0,3
0,3-0,6
<0,1
50,2-0,9
<0, 2-0,3
<0,2-1,6
_
3-16
24-35
6-9
63-70
26-23
_ 5-7
99-126
0,2-0,4
31-52
_
<50
_
<100
<100
«50
<5
<25
<25
52-66
85
<25
<25
140-210
40-195
-
Aver.
650
212
56
0,2
0,3
0,5
0,4
0,3
0,9
_
9
27
7
66
27
7
106
0,3
38
_
<50
_
<100
<100
<;o
<5
<25
<25
59
85
<25
'25
182
109
-
1973
Kin/max.
7-6-8,5
623-105!
256-305
14-29
<0,1-0,6
<0,2-0,4
«0, 2-2,1
<0, 2-0,9
<0,2
<0, 2-1,0
_
23-35
70-141
14-18
53-65 _
14-21
12-38
72-149
0,4rO,9
20-44
_
<50
-
<100
<100-360
<50
<5
<25
<25
<25
-
<2 5-160
<25-32
<25 _
, <25
30-400
<25-76"
-
Aver.
826
284
22
0,3
0,3
0,8
0,4
<0,2
0,6
_
31
97
16
59
18
23
109
0,7
29
-
.5° .
<100
193
<50
<5
<25
<25
<25 _
74
30
<25
<25
253
42
-
1974
Min/max.
7.7-8.3
279-1121
41-415
20-340
0.1-0,7
<0,2-0,5
0,3-2,0
0,2-1,6
<0,2
0,2-0,8
_
3-40
1-164
3-20
40-68
1-23
10-50
44-152
0-0,8
0.5-47
_
<50
63
320
<50
<5
<25
<25
<25
69-80
207
<25
<25
50-450
" 33^50-
-
Aver.
860
159
94
0,4
0,3
1,0
<0,1
0,7
0,2
0,4
_
17
51
12
54
8
34
82
0,4
18
_
<50
-
63
320
<50
<5
<25
<25
<25
-
73
207
<25
<25
230
K
Mote: All commas in tables denote decimal points.
alteration in its molecular structure as
molecular structure defines the toxicity of
a particular compound. No single method
will suffice and multiple chemical analyses
are necessary to cover the wide range of
pollutants which may be present in water.
The following methods have shown promise:
(a) Adsorption onto activated carbon and
subsequent recovery of organic material
with solvents such as chloroform and
methanol. The suggestions put forward
by Middleton and his co-workers at the
EPA, Cincinnati are followed.
(b) Counter-current distribution analysis
is done using an automated Graig appa-
ratus. Some of the inherent short-
comings of the activated carbon method
are eliminated.
(c) Preparation of a benzene extract by
using a blender such as an Ultra Turrax.
The benzene is then reduced to a small
volume in a rotary evaporator and
finally concentrated in a Kuderna-Danish
evaporator to a volume of 10 to 5° }*•%•
This extract may then be used to test
for carcinogens by thin layer chromato-
graphy (2l).
(d) A number of analytical techniques for
the isolation and characterisation of
organic matter are being developed,
meanwhile the technique of finger
printing is used to compile an archive
of data which may be used for retro-
spective studies. Finger printing
includes the plotting of ultraviolet,
infra-red and fluorescence spectra of
the isolated organic material.
(e) A gas chromatograph/mass spectrometer
(GO/MS) combination is used in the ana-
lytical determinations, and programmes
for data storage and computer processing
are being developed to reduce the time
required for processing the data. A
benzene extract (prepared as before) is
injected into the GC (4$ Dexil 400 on
111
-------
TABLE 2. DRINKING WATER CRITERIA TOR CHEMICALS WHICH MIGHT AFFECT
PUBLIC HEALTH, AS LAID DOWN 51 TEE WORLD HEALTH ORGANIZATION
(WHO), USA PUBLIC HEALTH SERVICES (USPHS), SOUTH AFRICAN
BUREAU OP STANDARDS (SABS) AND RUSSIA (USSR). All
concentrations are expressed aa ug/e unless otherwise stated
TABLE 3. KNOWN ORGANIC CARBONS IDENTIFIED IS HDMUS TANK
EFFLUENT (HTE), TAP WATER (TW) AND RECLAMED
WATER (RW)
Constituent
Arsenic-
Barium
Beryllium
Cadmium
Chromium (hexawLlait)
Cobalt
Copper
Cyanide
Carbon chloroform
extractables (CCE)
Hydrogen sulphide
Lead
Mercury (total)
Hickel
Phenol compounds
Selenium
Strontium
Zinc
Silver
Nitrate (NOj) ag/t
Fluoride mg/t
Bacteria
Viruses
Quality criteria laid down by
WHO
International
norms
(1971)
50
N.S.
N.S.
10
N.S.
N.S.
50
50
N.S.
N.S.
100
1
N.S.
1
10
N.S.
5 000
N.S.
45
0,6-1,7
N.S.
N.S.
European
norms
(1970)
50
1 000
N.S.
10
50
N.S.
50
50
200-500
50
100
N.S.
N.S.
1
10
N.S.
5 ooo
N.S.
<50
0,7-1,7
nil/100
HE
nil/6 on
testing
of 10 C
USPHS
(1962)
10
1 000
N.S.
10
50
N.S.
1 000
10
200
• N.S.
50
N.S.
N.S.
1
10
N.S.
5 ooo
50
45
0,6-1,7
N.S.
N.S.
SABS
(1971)
50
N.S.
N.S.
50
50
N.S.
1 000
10
N.S.
N.S.
50
N.S.
N.S.
1
N.S.
N.S.
5 ooo
N.S.
10 as N
1,0-1,5
nil/100
me
N.S.
USSR
(1970)
50
4 000
0,2
10
100
1 000
100
100
N.S.
nil
100
5*
100
1
1+
2 000
1 000
10 as N
1,5
N.S.
N.S.
N.S. = Not specified
* = For organic compounds
+ = As SeOj"
chromosorb G, acid washed,. 80 to 100
mesh at 100 °C) and the temperature is
then programmed from 100 °C to 310 °C
at a rate of 2 °C/min. The mass
spectra are obtained simultaneously.
(f) Hexane extraction is used to determine
chlorine, sulphur, phosphorus and
nitrogen-containing pesticides by means
of gas chromatography.
(g) Molecular mass distribution patterns
are determined by consecutive filtration
through molecular membranes. Organic
molecules are divided into the following
five mass groups: more than IOC 000,
10 000 to 100 000, 1 000 to 10 000, 500
to 1 000 and less than 500.
With the techniques described, a number
of different carcinogens have been identi-
fied from waters by thin-layer chromato-
graphy (Table 3). Mole mass distribution
studies have shown promise in evaluating
the mole mass distribution of the total
organic loading of various types of waters.
Numerous extracts have been prepared and
are at present under investigation by GO/MS.
Compounds tested for
— ^— — . •—
3 methylpyrene
3,4 benzopyrene
22 methyleholanthrene
perylene
fluoranthene
9,10 benzophenanthrene (triphenylene)
1,2,5,6 dibenzanthracene
1,2,3,4 dibenzanthracene
coronene + = present
- = absent
TW
V^HH^V
+
+
+
+
+
-
-
-
-
HTE
+
+
+
+
+
-
-
_
-
RW
MriWMB^^B^
+
-
-
-
+
-
-
_
-
Quality surveillance of municipal
wastewater
The South. African standards for the dis-
charge of purified sewage and industrial
effluents are summarised in Table 4, with
the addendum that no other constituent is
allowed which may be harmful or poisonous
to man, other animals, fish or other water
life, or is detrimental to agriculture.
These parameters- were used for evaluating
the efficiency of representative sewage
treatment works in the areas under
observation.
Area A
A sewage works treating domestic wastes
has been under intensive microbiological
monitoring for the past five years, as its
effluent is directly reclaimed for potable
use. The yearly averages of the bacterial
and viral counts of the raw sewage entering
the plant are higher than in the other
works studied. These averages are reduced
by 1 to 2 log units during biological fil-
tration and secondary settling (3). Further
treatment of the humus tank effluent through
a series of maturation ponds reduces the
microbiological counts to well within the
limits for safe discharge into receiving
waters. The chemical quality of the matura-
tion pond effluent is also good, especially
with regard to ammonia and phosphate levels.
The judicious exclusion of industrial
wastes ensures the required standard of the
works effluent for discharge into receiving
waters.
Area B
The testing of a sewage works in this
area, receiving a large amount of industrial
wastes was ideal for the evaluation of
112
-------
TABLE 4. THE GENERAL STANDARDS FOR TREATED INDUSTRIAL
EFFLUENTS AS GAZETTED BY THE S.A. GOVERNMENT
R533 (1962). (Concentrations in mg/t unless
otherwise stated.
Parameter
pH
Dissolved oxygen
E. ooli (faecal )/100 mC
Temperature
Chemical oxygen demand
Oxygen demand
Total dissolved solids
Suspended solids
Sodium (as
Soap, oil and fats
Residual chlorine (as
Free ammonia (as
Arsenic (as
Boron (as
Hexavalent chromium (as
Total chromium (as
Copper (as
Phenolic compounds (as
Lead (as
Cyanide (as
Sulphide (as
Fluorine (as
Zinc (as
N)
ci)
N)
As)
B)
Cr)
Cr)
Cu)
phenol )
Pb)
Cn)
s)
F)
Zu)
^^^^^^^^^•^•W^V^^M^^^^.^,^^^^^^^***
Limit
5,5 to 9,5
At least 75$ of
saturation point
nil
35 °C
75
10
500 above intake
water
25
50 increase
2,5
0,1
10,0
0,5
1,0
0,05
o,5
1,0
0,1
1,0
0,5
1,0
1,0
5,0
possible chemical pollutants which may
result from industry. The industrial
effluent is delivered to the sewage works
via a separate pipe line and is mixed with
the domestic sewage on site.
During 1973/1974 loadings of cyanide,
boron, iron, manganese, nickle and zinc weie
constantly high, but many of these metals
were reduced to the required low levels in
the finally treated effluent by sedimenta-
tion and dilution. The industrial effluent
showed variations in pH values of between
2.8 and 8.3. Nevertheless the effect of
the mixing of this effluent with domestic
wastes stabilised the pH levels in the humus
tank effluent to within normal limits. The
inclusion of industrial effluents in muni-
cipal wastewaters increased the chemical
loading to the sewage purification plant.
The microbiological testing of this works
will commence during 1975-
The purified effluent from another
sewage works in this area, receiving half
industrial and half domestic wastes, is used
as an influent to an experimental reclama-
tion plant. This effluent conformed to the
normal limits required for chemical dis-
charge (Table 4). Although the microbiolo-
gical load of the raw sewage was less than
that of a purely domestic waste, the
effluent did not conform to the required
bacterial standard for discharge into a
receiving water. The effluent (after con-
centration for virus evaluation) showed
cytotoxicity to monkey kidney cells.
A third sewage works with a low indus-
trial loading was studied for 52 weeks
during 1972/73. The concentrations of
heavy metals entering the plant were low and
the humus tank effluent was of a good
chemical quality. This effluent is further
treated in a series of maturation ponds
which ensures that the final effluent is of
a high standard before discharge into the
receiving stream.
Quality surveillance of drinking waters,
and their raw water sources
As the quality of a drinking water is
evaluated by its physical, chemical and
microbiological constituents, it is worth-
while considering some of the safety para-
meters used at the present time (Tables 2
and 5). Although not a gazetted standard,
no virus isolated per litre on the testing
of 10 6 of sample is used as a safety para-
meter for drinking waters in South Africa.
Area A
The surveillance of the drinking water
supplies to area A has been in progress for
the last five years, and an enormous amount
of data has been collected. An example of
such chemical data collected on a treated
.dam water and on two borehole waters is
shown in Table 1. The breakdown of this
type of data is illustrated in Figure 1.
¥ith such surveillance small and signifi-
cant changes in the quality of the drinking
water in question can be detected and
followed up.
The same technique applies in the weekly
microbiological analyses as shown in Figure
2. For example, the microbiological
loading was high in the raw dam waiter
source (ffl?5) of the treated drinking water
(MP8a). Evidence of faecal contamination
in the treated drinking water as shown by
the presence of E.. coli occurred during
1974 and, of more significance, the recovery
113
-------
TABLE '., A SUHMABY OF PROPOSED CRITERIA POH DRUHOITC WATER PREPARED FROM RELATIVELY
OHPOLHJTED SOORCES (WATER QUALITY CRITERIA, 1972)
Composition
Alkalinity
JLmmonia-N
Arsenic (total)
Bacteria
Pascal coli forma
Total eoliforms
Bariuo
Boron
Cadmium
Chloride
Chromium
Colour
Copper
Cyanide
Dissolved oxygen
Fluoride
Detergents
Hardness
Iron
Lead
Manganese
Mercury
Nitrate-K
Nitrite-N
Odour
Oil and grease
Organic material
CCS
CAS
Pesticides (halogens)
" (organie-P and
carbonates )
" ( chlorophenoxy
weedkillers)
PH
Phenolic compounds
Phosphate
Phthalic esters
Polychl orinated
biphenyl (PCB)
Selenium
Silver
Sulphate
Temperature
Total dissolved salts
Turbidity
Viruses
Zinc
Limit
N.S.
0,5 mg/e
0,1 rng/6
2000/100 m6
20 000/100 mC
1 mg/e
N.S.
0,01 rag/6
250 mg/e
0,05 nig/e
75
1 mg/E
1 mg/e
M.S.
1,4-2,4 rng/6
0,5 mg/e
N.S.
0,3 We
0,05 mg/e
0,05 mg/e
0,002 rng/e
10 mg/e
I mg/e
N.S.
0
0,3 mg/e
1.5 m«/e
0,1-1000 ug/e
100 Me/e
2-20 Wg/6
5,0 to 9,0
i wr/e
M.S.
-
H.S.
10 ug/e
N.S.
250 mg/e
N.S.
N.S.
N.S.
H.S.
5 mg/e
Comments
No recommendation, alkalinity associated with pH
and hardness, rapid changes must be avoided.
Indicates pollution, influences chlorination.
Adverse physiological effects.
Geometric mean of bacteria may not exceed these
limits in the raw water to be treated.
Adverse physiological effects. _
Harmful to plants, no knowledge of effect on
humans.
Adverse physiological effects.
Solely based on taste.
Harmful effects not yet demonstrated.
An aesthetic norm, is measured in P/Co units.
Results in taste and odour effects.
Toxic to fish. No effect on man in small doses.
Recommended to be as large as possible.
Based on temperature of water,
Aesthetic norm expressed as methylene blue
active substances (MSAS).
Depends on public acceptance.
Public acceptance, norm depends on dissolved Pe .
Toxic to man.
Aesthetic norm.
Toxic to man.
Adverse effects on man.
Adverse effects on man.
Aesthetic norm.
Water should not contain oil or grease.
Organic material adsorbed on activated carbon and
extracted with chloroform.
Organic material adsorbed on activated carbon and
extracted with ethanol.
Containing halogens have varying toxicities.
Total concentrations may not exceed 0,1 mg/e.
Weedkillers like 2,4D may not exceed 0,02 mg/e.
Causes taste problems.
Relationship between phosphates, biological
productivity, taste and filtration is complex.
Potentially dangerous, little available
information.
Little available information.
Toxicological information very scarce.
Silver hardly ever occurs in more than 1 ug/8.
Influences taste and has laxative properties.
Temperature must remain within aesthetic limits.
Limit is dictated by local conditions.
Low turbidities are essential for the effective
disinfection of drinking waters.
Methods available for the complete recovery of
virus from more than 10 e of water.
Taste problems.
N.S. Not specified
of virus during 1970, 1971, 1973 and 1974;
substantiating that faecal coliforms are
not reliable indicators of viral pollution.
Other sources of drinking water, i.e.
treated dam water (MP20), and borehole
waters (MP22 and MP23) all showed evidence
of bacteriological and viral pollution
during the test period. The microbiologi-
cal quality of reclaimed water (MP8a) on
the other hand was significantly better than
the other supplies and at no time could
virus be isolated from 10 E or even 100 2
of the product water.
Area B
The quality parameters for the various
water supplies tested since 1973, are
recorded graphically and can be compared
with given standards (Figure 3). The waters
tested all had chemical qualities within the
required health standards. This data may
then act as a baseline for the detection of
any increase in chemical pollution in the
area. These findings' may be used to assess
the quality of the reclaime'd water produced
by the experimental municipal wastewater
plant in this area (not used for drinking
purposes as yet). To date, this reclaimed
water complies with all salient chemical
requirements and was in fact mostly of
better quality than the other drinking water
sources, especially with respect to organic
carbon content.
The microbiological monitoring of this
area (see Figure 4) has occasionally shown
evidence of faecal coliforms in the treated
dam water (P2) and in the fountain and
spring waters (P4, P6 and P?). The major
water supply (R4) , taken from a polluted
river source, me'ets the required standards
probably on account of higher efficiency of
the water treatment process. No virus was
isolated from any of the drinking waters in
this area. Wo 13. coli/100 m€ or virus/100 I
were ever isolated from the final water from
the reclamation plant. Again the reclaimed
water was of equal if not better quality
than the other drinking waters supplied to
the area.
Cytotoxicity studies
An investigation of the methods to be
used in this study is still to be completed.
Cytotoxicity has been detected in the humus
tank effluent which constitutes the influent
to the reclamation plant in area B but not
in the reclaimed water. In-depth studies
are still necessary for the interpretation
of these cytopathic effects.
Investigations into the spread of
R+ bacteria
Extensive work on the presence and
significance of antibiotic resistant
bacteria in the water environment has been
done (19,22-25). Resistance (R) factors
are nucleic acid elements which are rapidly
transmissible by conjunction among gram-
negative bacteria. They confer on their
11)4
-------
Chemical oxygandomond (mg.Og/l)
Rudam*al*rl
MP9
1
TrMHH dam HMr 1
MP So
1
KWrJbullanffAnniHiH 1
MPIO
ffl
TruMd dam Mfer in
MPZO
flL
How
-------
hosts, resistance to antimicrobial drugs
and resistance to many other anti-bacterial
effects such as those of heavy metals,
ultraviolet light, phages, bacteriocins and
various chemicals. High numbers of coli-
form bacteria were found to carry R factors
in sewage effluents and in natural waters.
In the wastewater discharge of a hospital,
about six times as many coliforms carried R
factors as did the coliforms isolated from
the sewage effluent of the city in which
the hospital is located. Coliforms with R
factors were found to survive maturation
pond treatment and natural purification in
a river or a dam as well as, or better than,
their components without R factors. R
factors may be transmitted among bacteria
in the water environment, indicating that
polluted water may contribute to the spread
of R+ bacteria, which are a hazard in human
and veterinary medicine. More advanced
purification of sewage discharges with
complete destruction of all bacteria is the
only way by which the incidence of these
organisms in the water environment can be
reduced i.e. the direct reclamation of
sewage could solve this problem.
The determination of possible long-term
effects by bio-assay
Spent activated carbon from the recla-
mation plant in area A was treated with
chloroform and methanol to extract adsorbed
organic material. The recovered material
was then tested for carcinogenic activity
via the subcutaneous route in rats of a
¥istar-derived strain. The skin and sub-
cutis at the site of injection and the liver
from each rat were examined histologically.
A few pathological changes were observed in
the sections examined, but no lesions of
significance occurred in these sections.
The mean body weights of the eight groups
were similar throughout the experimental
period. The use of the rat's subcutaneous
tissue as a site for testing substances for
carcinogenicity is well documented and is
considered to give a very sensitive index
of carcinogenicity.
As no evidence of carcinogenic activity
of the extracts was obtained, testing of
extracts on other species by other routes
was considered. Instead of adsorbing the
organic material onto activated carbon with
subsequent recovery of the adsorbed material
by chemical means, rats are directly supplied
with the water to be tested. In doing so,
it is hoped to obtain a more realistic
picture of the effects of exposure to water
from different sources. The waters tested
are: humus tank effluent, reclaimed water
from area B, reticulated water from the same
area, and distilled water as control. In
addition, spent activated carbon is mixed
into the diets of rats to examine the effect
of oral intake of adsorbed organic material,
using new activated carbon as a control.
This experiment is being conducted over a
long period and no results are available
at this stage.
Fish have proved useful sensors of
quality changes in water and use is there-
for being made of a fish bio-assaying system
to continuously monitor reclaimed and other
waters for toxicity in area A (26,27). Pish
are also used to measure any long-term
effects of pollutants. Measurement of growth
tempos over 3, 6, 9 and 12 months and other
pathological investigations are being
carried out on fish housed in aquaria re-
ceiving reclaimed water as well as water
from other sources. Tests are also being
carried out to determine the toxicological
effects on fish of known pollutants, some of
these results have already been published
(28).
Epidemiological survey
Although epidemiological studies have a
low priority, information is still accumu-
lated in a study in area A, as described by
Grove (29), Data collected should form an
acceptable base line of gastro-intestinal
infections, central nervous system diseases,
hepatitis, and other miscellaneous diseases
which may be transmitted by water. To date
there does not appear to be any significant
change in the disease pattern in the area,
but valuable experience in the collection
and interpretation of data has been gained.
DISCUSSION AHD CONCLUSIONS
This research programme makes provision
for studies on eight different research
aspects, six of which are already in pro-
gress. Only two years of a ten year pro-
gramme have passed and it is rather early
to draw positive conclusions. However, use
has also been made of additional background
knowledge, gained over the years in the
qualities of freshwaters. and reclaimed
waters, together with data collected during
these two years, in an attempt to form a
base line on which to measure future devia-
tions in water qualities in the Republic.
116
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The waters under surveillance are represen-
tative of the over-all water supplies in the
country, the total area investigated includes
water supplied to 25 per cent of the total
population, and it is with these water
supplies that the quality of reclaimed
water may be compared. Concurrently, more
sensitive techniques for the determination
of micro-pollutants are being developed
which should assist in the setting of more
realistic standards for their limits in
drinking waters.
It is not feasible to test the safety
of a drinking water prior to its use. Some
of the analyses, e.g. viruses, take up to
30 days to complete. Enormous reservoirs
would be required if water were to be
stored until such results were available.
Analytical results can therefore only be
used to confirm the quality of a water.
Reliance should rather be placed on a know-
ledge of the source of the water, on the
efficiency of the treatment process used
and the control of process operations. All
these factors are built into the present
reclamation processes. In the above study,
in all the cases where micro-organisms were
found in drinking waters, their presence
was the direct result of poor plant
operation or design.
Industrial effluents should be treated
separately from domestic sewage. This would
minimize the effect of the discharge of new
and complex chemicals on sewage purifica-
tion processes and ensure their absence
from reclaimed municipal wastewaters.
Epidemiological and bio-assaying studies
have not been able to demonstrate any
adverse health effects from the use of
reclaimed water on humans and rats.
The quality of the reclaimed water, tested
to date, meets all the quality standards
and is equivalent to or better than the
best drinking waters obtained even from
protected surface water resources.
It is concluded that more research is
needed to determine:
1. ¥hat pollutants are present in the
water environmeit.
2. The quality of drinking water supplies
now and. in the future.
3. The influence of industrial wastes on
municipal wastewater effluents.
4. Oncogenic effects by means of cell
culture studies.
5. The possibility of the spread of R+
bacteria .
6. The long-term effects of pollutants
by bio-assaying techniques.
7. The immunological pattern in the
receiving community.
8. The continuing development of analyti-
cal techniques for use in the above
tasks .
9. The most efficient methods of control
of plant operation, design and
automation.
ACKNOWLEDGEMENT
This paper is published with the
permission of the Director of the National
Institute for ¥ater Research.
REFERENCES
1. Nupen, E.M., "Virus Studies on the
Windhoek Wastewater Reclamation Plant
(SWA)". Water Res.. 4, 661-672 (1970)
2. Nupen, E..M. and Stander, G.J., "The
Virus Problem in the Windhoek Waste-
water Reclamation Project". Paper
presented at the 6th Intl. Water Poll.
Res. Conf., Jerusalem (June 1972).
3. Nupen, E.M., et al.. "The Reduction of
Virus by the Various Unit Processes
used in the Reclamation of Sewage to
Potable Waters". Paper presented at
Conf. on Viruses in Water and Waste-
water Systems. Austin, Texas
(April 1974).
4. Funke, J.W. and Coombs, P., "The Removal
of Shock Load of Heavy Metals and of
Cyanides from Humus Tank Effluent
during the Stander Water Reclamation
Process". Project Rept No. 4,
6201/6434, NIWR, CSIR, Pretoria, RSA
Funke, J.W. and Coombs, P., "The
Removal of Heavy Metals and Cyanides
from Humus Tank Effluent during the
Stander Water Reclamation Process".
Project Rept No. 5, 6201/6434, NIWR,
CSIR, Pretoria, RSA (l972).
Sattor, A.S. et al. "Removal and
Inactivation of Poliovirus during Lime
(Calcium Hydroxide) Treatment of
Sewage". IRCS (Research on Biomedical
Technology, Microbiol. Parsitol. and
Inf. Diseases; Social and Occupational
Bed.), 2, 1635 (1974).
117
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7. Van Vuuren, L.R.J., et al.. "Advanced
Purification of Sewage Vorks Effluent
using a Combined System of Lime
Softening and Flotation". Water Bes..
1, 463-474 (1967).
8. Grabow, W.O.K., et al.. "The Bacterio-
logical Effect of Lime Flocculation-
Flotation as a Primary Unit Process in
a Multiple System for the Advanced
Purification of Sewage ¥orks Effluent".
¥ater Res.. 2., 943-953 (1969).
9. Van Vuuren, L.R.J., et al.. "The Full-
scale Reclamation for the Augmentation
of the Domestic Supplies of the City
of Windhoek". Paper presented at the
5th Intl. Water Poll. Res. Conf., San
Francisco (Aug. 1970).
10. Van Vuuren, L.R.J. and Henzen, M.R.,
"Process Selection and Cost of Advanced
Wastewater Treatment in Relation to
the Quality of Secondary Effluents and
Quality Requirements for Various Uses".
Paper presented at the IAWPR Special-
ised Conf. on 'Application of lew Con-
cepts of Physical-Chemical Wastewater
Treatment', Vanderbilt Univ., Nashville,
Tennessee, USA (18-22 Sept. 1972).
11. Clarke, N.A., et al., "Human Enteric
Viruses in Water Source, Survival and
Removability". Adv. in Water Poll.
Res.. 2. (1962).
12. "Engineering Evaluation of Virus Hazard
in Water". Report. Committee on En-
vironmental Quality Management of the
Sanitary Engineering Division. Jour.
San. Eng. Div. Proc. Amer. Soc. Civil
Engr.. 7162. SA1. Ill (lQ70).
13. "Re-use of Effluents Methods of Waste-
water Treatment and Health Hazards".
Tech. Rept WHO Meeting of Experts.
WHO Tech. Series Ho. 517, Geneva (l973).
14. Bishop, R.F., et al.. "Detection of a
Ifew Virus by Electron Microscopy of
Faecal Extracts of Children with Acute
Gastroenteritis". Lancet. 149 (Feb. 2,
1974).
15. Paver, W.K., et al.. "A small Virus in
Human Faeces". Lancet. 237 (Feb. 3,
1973).
16. Kapikian, A.Z., et al.. "Visulization by
Immune Electron Microscopy of a 27 nm
Particle Associated with Acute Non-
bacterial Gastroenteritis". Jour.
Virol.. 10(5), 1075 (1972).
17. Nupen, E.M., "Microbiological Quality of
Water Supplies". Paper presented at
Inst. Water Poll. Control and SAICE
Symp., Johannesburg (l973).
18. "Microbiological Methods Guide". CSIR,
NIWR (1974).
19- Grabow, W.O.K., et al.. "Survival in
Maturation Ponds of Coliform Bacteria
with Transferable Drug Resistance".
Water Res.. 1, 1589-1597 (1973).
20. "Standard Methods for the Examination of
Water and Wastewater". 13th Ed., Amer.
Pub. Health Assn., New York, N.Y. (l97l).
21. Borneff, J. and Kunte, H., "Kanzerogene
Substanzen in Wasser und Boden". Arch.
Hyg.. 152(3), 220-229 (1969).
22. Grabow, W.O.K. and Prozesky, O.W.,
"Drug-resistance of Coliform Bacteria
in Hospital and City Sewage". Antimi-
crob. Ag. Chemoth.. 2., 175-180 (1973).
23. Grabow, W.O.K. and Nupen, E.M., "The
Load of Infectious Microorganisms in
the Wastewater of two South African
Hospitals". Water Res.. 6_, 1557-156?
(1972).
24. Grabow, W.O.K., "Drug-resistant Coli-
forms call for Review of Water Quality
Standards". Water Res.. 8, 1-9 (l974)-
25. Grabow, W.O.K., et al.. "Behaviour of a
River and Dam of Coliform Bacteria with
Transferable or Non-transferable Drug-
resistance". Water Res, (in press).
26. Morgan, W.S.G. and Kuhn, P.O., "A Method
to Monitor the Effects of Toxicants
upon Breathing of Large Mouth Bass
(Micropterus salmoides Lacepede).
Water Res.. 8.(l), 67-77 (l974).
27. Morgan, W.S.G., "Monitoring Pesticides
using Changes in Electrode Potential
caused by Fish Opercular Rhythms".
Paper presented at 7th Intl. Water Poll.
Res. Conf., Paris (Sept. 1974)-
28. Kuhn, P.C. and Morgan, W.S.G., "An
Electrode System to Monitor the Effects
of Changes in Water Quality on Fish
Opercular Rhythms". Bioeng. and
Biotechnol. (in press).
29. Grove, S.S., "The Epidemiology of
Reclaimed Water". 51st Conf. Inst. of
Municipal Engineers of S.A., Windhoek
(SWA) (June 1974).
DISCUSSION
COMMENT: Mr. Robert T. Christian, Univer-
sity of Cincinnati, Ohio. I wish to compli-
ment you on the wide range of tests you are
using. I was particularly interested in
your cell culture type tests. We, too,
have studied raw waters and finished waters
and direct reuse waters, and I would like
very much to compare results with you.
118
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COMMENT: Dr. Lennette, State of Cali-
fornia, Biomedical Labs., Department of
Health, Berkeley, California. This is
not with specific reference to Dr.
Nupen's presentation, but in response to
everything I have been hearing all day,
I would like to make a few comments on
viral taxonomy and nomenclature.
About thirty years ago, there was de-
vised the term arboviruses which was a
catch-all designation for classifying
those viruses transmitted by insects—
arthropods. Subsequently, with the era
of the tissue culture, we began to isolate
viruses in culture and, as you know, there
was an era in which we talked about
enteric, cytopathic, human organic viruses.
This subsequently became what we refer to
as enteroviruses.
Also, about the same time, there was
recovered a group of viruses now known as
the adenoviruses. In their characteris-
tics, except for morphology and the genetic
material, they could clearly fall into the
enteroviruses because they are found in
the gut.
I would remind all concerned that the
mere fact that an agent occurs in the
gut—in the intestine—is no indication
and no proof that it is transmitted by
the water route. I give you an example.
We were just talking here this afternoon
about the hepatitis virus resembling, if
I got the message right, the enterovirus
group. Now there have been other agents
in this group which are now being separat-
ed out on the basis of morphology, and the
mere fact that an agent falls into this
group is no proof that it is water-borne.
In the adenovirus group itself, there
are several agents which produce disease
that has nothing to do with the respira-
tory tract. As a matter of fact, adeno-
virus Type A produces a conjunctivitis,
and yet you can find the virus in the gut.
If you get over to the enterovirus
group, there is a very outstanding example
of a recently discovered entervirus which
is responsible for a newly emerging di-
sease known as hemorrhagic conjunctivitis.
This agent possesses all the characteris-
tics of an enterovirus, is found in the
stools, and yet is not transmitted by that
route. So the mere designation of
entero/irus should not be assumed to be
a label indicating that this agent is,
first, necessarily transmitted by water
or, secondly, has the gastrointestinal
tract as a portal of entry.
QUESTION: Mr< Clive C. Solomons, Uni-
versity of Colorado Medical School. I
would like to ask you whether there was
any particular problem in eliminating the
Filaria parasite during the purification
process?
QUESTION: Mrs. Nupen. What was it?
RESPONSE: Voice from the Floor.
Schistosomiasis.
QUESTION: Mr. Solomons, University of
Colorado Medical Center. O.K. Was that
a particularly difficult parasite to get
rid of?
RESPONSE: Mrs. Nupen. Actually that's
an awfully good question. I haven't been
asked that one before. Unfortunately,
the National Institute for Water Research
(NIWR) does not really deal much with
Schistosomiasis, because we have a separate
Bilharzia Research Unit which investigates
all problems relating to the control of
this disease in South Africa. Research
has shown that the cercariae in water do
not survive longer than 48 hours. They
are also killed by low doses of chlorine
(1 ppm) and by excess lime treatment.
The miracidia, which could presumably be
present in municipal wastewater, die after
24 hours if they do not reach a snail host
and are killed by 1 ppm free chlorine in
contact time 30 minutes. I therefore see
no particular problems relating to the
transmission of Schistosomiasis by re-
claimed wastewater.
The parasites we are interested in at
the NIWR are species of Ascaris, Taenia
Strongaloides and Hookworm, all of which
are common parasitic infections in
Southern Africa. All the above species
are successfully removed by sedimentation
during treatment with excess lime. The
ova, however, can be recovered from the
resultant lime sludge, and research is
necessary to ensure their inactivation
prior to the disposal of such solid wastes
for agricultural purposes.
119
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PLANNING FOR WATER REUSE: SOME SOCIO-ECONOMIC ASPECTS
J. Gordon Milliken
Industrial Economics Division
Denver Research Institute
University of Denver
Denver, Colorado 80210
Lucy Black Creighton
Department of Economics
Colorado Women's College
Denver, Colorado 80220
ABSTRACT
Economic trends in water resources development, in agriculture, and in energy, to-
gether with environmental concerns and regulatory trends affecting wastewater discharge
quality, combine to strengthen the case for potable use of recycled water. This paper
analyzes the factors which are causing cities to consider reuse of water and indicates
some of the socio-economic problems which may occur: (1) possible differences between
the public's indicated attitude toward potable use at some future date, and that attitude
when directly faced with such use; (2) problems faced by cities pioneering reuse; (3)
problems arising from differential application of recycled water among neighborhoods
within a municipal system; (4) the need for contingency plans if scheduled implementation
of water reuse should be delayed by the discovery of serious health effects; (5) politico-
economic conflicts arising between water supply and wastewater treatment agencies,
including the problems of equity and efficiency in allocating the costs of reused water
treatment; (6) water pricing; (7) in view of rising energy costs, the economic aspects
of energy required for wastewater reclamation for reuse; and (8) implications of reuse
for downstream water users. Numerous uncertainties exist in these topical areas, and a
coordinated research program to provide guidance to policy makers is clearly in the public
interest.
INTRODUCTION
The case for renovating and directly
recycling wastewater from municipal and in-
dustrial sewage is increasingly gaining
support in the United States today. In
spite of the fact that some people may view
with aversion the prospect of having
treated wastewater come through their
household water taps, technology has made
it possible to return wastewater to a
quality level which with few, though never-
theless important, exceptions equals that
of pure natural sources. While the cost of
treatment is still relatively high, there
is every expectation that it will decrease
over the years as the technical processes
are further refined. However, the most
significant sources of support for the use
of recycled water owe less to the technical
ability to purify wastewater than to a
number of other considerations having to do
with problems of developing new "fresh"
water supplies and disposing of municipal
and industrial wastewater.
As water use in the United States in-
creases, the costs of developing new conven-
tional water supplies continue to climb,
and in many areas of the nation, traditional
sources of municipal and industrial water
are beginning to be fully appropriated. The
problem is particularly severe in arid and
semiarid areas, but it is increasingly evi-
dent in more humid areas as well. Concur-
rently, the task of dealing with domestic
and industrial wastewater becomes more
onerous as population continues to concen-
trate in urban areas. The volume of such
wastes is increasing; it includes ever
greater levels of pollutants, and it is
difficult to dispose of. Not only is this
120
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waste an aesthetic problem, but it has led
to the pollution of conventional sources
of drinking water, both surface and, in
some cases, groundwater. Moreover, pro-
viding for new water supplies and for safe
effluent disposal have both been made more
difficult by recent changes in the public's
attitude toward the environment. These
changes, largely reflected in EPA regular
tions, have imposed restrictions on the
development of new water supplies and on
the unregulated disposal of untreated
municipal and industrial wastes. It is not
surprising, then, that recycling, which
takes wastewater and processes it into
usable water supplies, is being proposed
as a solution to the problems of both fresh
water supplies and used water disposal.
Furthermore, given the requirements
for wastewater quality under the current
pollution regulations, it may soon be the
case that much of the wastewater will have
to be of as high, or higher, quality than
is much of the current supply of "fresh"
water. It has been estimated that on the
average effluent already constitutes about
three percent of the M&I water supplies of
some third of the nation's population, and
in some cities reaches 20 percent of sup^
plies.* Thus, recycling water becomes an
attractive option both from the point of
view of deteriorating fresh water supplies
and of increasingly high quality wastewater.
In recent years a great deal of re-
search has been done on various aspects of
wastewater renovation—the potential of re-
used water in industry and agriculture, the
technical processes for renovating water
from sewer effluent, the costs associated
with different degrees of renovation, com-
parisons of costs of renovated water and of
water from more conventional sources—have
all received attention. In the socio-
economic area, however, less research has
been done. This paper describes certain
social, attitudinal, political and economic
topics where uncertainty exists, and points
the way for a research program which can
help to provide answers for the water reuse
planning process.
ATTITUDES TOWARD REUSE
The instinctive public attitude to-
ward consumption of water reclaimed from
sewage is one of disgust or fear (or in
milder forms, suspicion). This is based
on a cultural taboo against association
with bodily wastes, which predates an
awareness of the association between germs
and disease. Given a free choice, it is
probable that most persons would shun the
recycled water in favor of "fresh" water,
even if they were assured of equal purity.
In spite of a widespread awareness, for
example, that astronauts on space flights
consume water which is recycled from
bodily wastes by advanced engineering pro-
cesses which eliminate the possibility of
contamination, it appears that few persons
would voluntarily choose such water for
drinking, so long as a fresh water source
were available. What will be the signifi-
cance of this attitude when municipal re-
cycled water becomes a reality? Will the
public accept recycled water for potable
use, or will the public require some form
of dual system, at considerable expense,
to segregate recycled water for industrial
or other nonpotable use?
Table I shows the results of nine
attitude surveys designed to measure pub-
lic acceptance of drinking reclaimed
wastewater. The results of the surveys
are varied. They show a spread of willing-
ness, from less than 40 percent to over 80
percent. This spread can be attributed to
many factors: questionnaire design; res-
pondent assumptions; awareness of water
problems; geography; and so forth. It is
worth noting that absence of choice raises
the acceptability of recycled water. In
the Carley study, drinking reused sewage
water ranked lowest of all (37.8 percent
approving) when respondents were given a
choice of seven water supply alternatives.
However, when not faced with a choice, and
given the criterion that the recycled
water would be equal in quality to present
house water, 84.1 percent showed some de^
gree of approval.*
*Jerome Gavis, Wastewater Reuse, Wash-
ington: National Water Commission,
1971, p.3.
*The Carley study results were: "Yes,
definitely," 52.8 percent; "Probably so,"
23.7 percent; "Not sure, but tend to think
so," 7.6 percent.
121
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TABLE I. PERCENTAGES OF RESPONDENTS WILLING TO DRINK RECYCLED WASTEWATER
Survey Date
Survey Location
Author
Percentage
Willing
1965 Texas, Kansas, Massa-
chusetts, Illinois
1971 Kokomo, Lubbock, San
Angelo, Colorado
Springs, Santee
Baumann
Sims and Baumann
61.4%*
48.0%
1971
1971
1972
1972
1972
1973
1974
Nationwide
Philadelphia, Camden,
Cincinnati, Tucson,
Portland, Oregon
Northern California
Southern California
Denver
Nationwide
Southern California
Ackerman
Johnson
Bruvold
Bruvold
Carley
Gallup Poll/AWWA
R. Stone & Co.
60.0%
77.4%
45.0%**
42.7%**
37.8% (84.1%)***
38.2%
39.1%
*Ranging from 46 percent in Massachusetts to 74 percent in Illinois.
**Bruvold's responses were reported as a percentage opposed to such use, i.e., 55.0
percent opposed in Northern and 57.3 percent opposed in Southern California. The re-
mainder, as shown in the table, are not necessarily willing to drink recycled water,
i.e., some may be uncertain.
***In the Carley study, the 84.1 percent were asked if willing, if water quality
were the same as present house water. Without this qualification, and confronted with
a choice of alternatives, only 37.8 percent approved.
122
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Only scattered evidence exists as to
what people will actually do when con-
fronted with using recycled water, but this
evidence tends to support the Carley study.
In Windhoek, South West Africa, where
direct water reuse is practiced, the
quality of recycled water is high and pub-
lic acceptance has been good. In Chanute,
Kansas, however, where a poor quality re-
cycled water was used during a 1956-57
water shortage, public reaction was nega-
tive and many persons brought water from
neighboring towns or bought bottled
water. *
The limited experience with reuse and
the variation in survey results indicate
that much is still to be learned in this
area. Some observers rely on faith that
intellectual assurances by public health
experts and city officials will avert
"irrational" public attitudes opposed to
recycled water. They suggest a campaign
of education and endorsement by experts to
mold public opinion. But any such cam-
paign must be grounded in existing atti-
tudes. How many of the favorable res-
ponses, for instance, are due to public
support of a program seen as environment-
ally responsible? How many favorable re-
sponses are given glibly, with the com-
forting knowledge that actual experience
is remote in time and probability? (One
is reminded of the lengthy reservation
list of world's fair visitors some years
ago, who indicated a desire to be a pas-
senger on the first rocket to the moon.)
Will intellectual reason change to emotion-
al distrust when recycled water first flows
from the tap?
\
As a warning, attention should be
directed to analogous campaigns in recent
years to promote fluoridation of drinking
water. Despite repeated assurances by
dental experts and others of the scientific
community, there was widespread rejection
of fluoridation in public referenda,* and
highly emotional appeals against "rat
poison" and "communist subversion of our
water supply." Technical planning for
water recycling is a five- to ten-year
process; realization of its potential re-
quires public understanding and support.
Problems of Cities Pioneering Reuse
To pursue this question of attitude
one step further, what problems will be
faced by cities which pioneer potable re-
use? Will the public take little or no
notice of direct reuse as is the case now
with cities using recycled water for park
irrigation? Will visitors pay attention
only if the water is unusually hard or
brackish? Or will knowledge of direct
reuse bring significant public reaction,
such as occurred in recent months in New
Orleans and Duluth as a result of unfavor-
able publicity about their water supplies?
What possibility exists that the first
U.S. city to undertake direct potable re-
use might suffer economic effects, such
as loss of convention business, a drop in
tourism, or sales resistance to food or
beverage products produced there? Unless
research shows that these, concerns are
minimal, uncertainties of this sort appear
likely to remain barriers to recycling.
DIFFERENTIAL APPLICATION OF RECYCLED WATER
One potential problem of considerable
significance appears to have received
little or no attention. This is the pro-
blem of differential geographical appli-
cation of recycled water within a municipal
system. Most cities of substantial size do
not have a single source of water and a
single reservoir. The common occurrence
is a mixture of water supplies from several
different sources. Often there also are
several water treatment plants and several
water storage reservoirs, each serving a
particular section of the city. What
happens with direct reuse when the city's
*Baumann, Duane D., and Roger E.
Kasperson, "Public Acceptance of Renovated
Waste Water: Myth and Reality," Water
Resources Research, Vol.. 10, No. 4,
August 1974, pp. 667-674.
*James F. Johnson pointed out this
analogy in Renovated Waste Water, Chicago,
Illinois: University of Chicago, 1971.
123
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water recycling plant, located at or near
a major sewage treatment plant, comes on
line? Efficiency of the distribution
system would dictate that the recycled
water be pumped to water storage reservoirs
in the general vicinity of the sewage
treatment plant. And since gravity sewer-
age systems are normal, these reservoirs
would be in the section of the city of
lowest elevation, nearest the outlet
waterway which drains from the city. The
result of all this is that, normally,
neighborhoods near the river basin, in the
lowest elevation of the city, would be
most likely to receive recycled water.
Neighborhoods in higher elevations, at the
upstream end of the city, would more likely
receive water supplies from traditional
sources.
It is a foregone conclusion among
knowledgeable water resource professionals
that recycled water will not be added to
the normal water supply until it is demon-
strably of equal quality. Thus in theory
it should not matter if one neighborhood
receives water from a recycling plant
while another neighborhood receives water
originating in a hillside spring, But
this difference certainly will cause
grave problems of resistance among those
consumers who are supplied with recycled
water when this fact becomes known. This
problem will become even more difficult if
those consumers happen to be economically
disadvantaged, or an ethnic minority. Yet
it is possible and even probable in many
cities, that the section of the city
nearest the river, and hence the recycling
plant, is older and contains more low in-
come and minority residents that the more
distant, newer neighborhoods. It is not
without reason that the term "house on the
hill" is synonymous with affluence.
One topic for socio-economic research,
therefore, is an analysis of strategies
that can minimize or eliminate this source
of resistance. What should be done if
there is to be selective distribution of
recycled water in a city? Should there be
an educational campaign in advance? Should
there be some economic benefit to the area
receiving recycled water, such as a dual
price system, or would this backfire by
implying an inferior quality of recycled
water? Should there be an attempt to
equally distribute recycled water to all
areas of town, regardless of distribution
expense?
SOCIAL AND ECONOMIC DISRUPTIONS
THROUGH DELAY OF REUSE
In spite of uncertainties about pub-
lic acceptance, it does appear that ex-
pectations for recycled water to become
a viable alternative to conventional water
supplies are rising. This is most notably
true of environmental activists, who view
recycling as ecologically sound while con-
ventional water supply techniques, e.g.,
diversion from streams, construction of
storage reservoirs, are viewed as environ-
mentally damaging. Yet questions about
the health effects of recycled water are
far from settled. The problem to be dealt
with here is what to do should implementa-
tion of recycled water schemes be suddenly
halted by new evidence of recycled water
danger.
This environmental pressure is very
real and very powerful. William R. Seeger,
former General Manager of a California
water district describes this phenomenon:
"The Marin Municipal Water Dis-
trict in Marin County, California,
over the past several years had two
bond issues defeated that were de-
signed to provide a supplemental water
supply for the community. I can say
unequivocally that one of the major
objections that was brought up which
was effective in defeating our bond
issues was the accusation that we had
not adequately taken into considera-
tion the possibility of the reclama-
tion and reuse of wastewater. Our
first issue was defeated on a 9-1
vote, which is probably the largest
defeat of any major water bond issue
in the country. . . . Frankly, I
believe that in any program for
supplemental water supply, the suc-
cess of any bond issue is question-
able if the possibility of reuse of
wastewater is not considered and pre-
pared as a viable alternative. It
was suggested to us that if we would
include, as part of the bond proposal,
money for the construction of a waste-
water project regardless of the eco-
nomics, we could then anticipate a
favorable vote and support from those
who previously led the opposition."*
R. Seeger, "A Water Manager's
Perspective in Water Reuse," presented at
124
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Another example of environmental sup-
port for recycling can be found currently
in the Denver Metropolitan Area, where
environmental groups are opposing con-
struction of a storage reservoir on the
Upper South Platte River. In draft state-
ments prepared for the Bureau of Recla-
mation's Feasibility Report on the so-
called "Two Forks" project, recycling was
recommended as an alternative by represen-
tatives of three environmental groups
opposing construction of the dam and
reservoir for the Denver water supply
system.
There can be little objection to ac-
tive consideration of water recycling as
an alternative strategy for water supply,
and many cities are proceeding on the
assumption that recycling for potable use
will become feasible in another 15 years
or so. The problem which could arise,
however, is that public health hazards may
not, after all, be overcome when scheduled.
What happens in 1990 or 1995 if this
occurs? What social and economic dis-
ruptions follow? If a city has abandoned
development of conventional supply sources
in anticipation of successful reuse, it
cannot reverse strategy and develop these
sources in less than a decade or so. In-
stead, the city would probably face
forced conservation of potable use, and
expensive dual systems which provide re-
cycled water for various nonpotable uses.
The research which appears to be indicated
is an assessment of the social and eco-.
nomic impacts on an area, in case potable
reuse is indefinitely delayed and the
implementation of contingency plans be-
comes necessary.
CONFLICTS BETWEEN WATER SUPPLY
AND WASTEWATER TREATMENT AGENCIES
Traditionally in the United States
water supply systems have been separate
from wastewater treatment systems. In
many areas there are different adminis-
trative organizations for each with
separate costing and billing. Certainly
in the minds of most consumers the two
the 94th Annual Conference, American Water
Works Association, Boston, Massachusetts,
June 19, 1974.
systems are separate and distinct. Plan-
ning for water recycling, however, points
up the artificiality of this separation
and problems of both efficiency and equity
which must be considered.
An objective look at a municipal water
supply and wastewater treatment system
rather clearly demonstrates the technical
and economic relationship of the systems.
When water recycling evolves from advanced
wastewater treatment, the interdependence
of the systems becomes even clearer. In
particular, the cost of renovated water
is closely linked to the level of waste-
water treatment. The higher the quality
and therefore the cost of wastewater
effluent the lower will be the additional
costs necessary to produce recyclable
water. The product of one system becomes
the input of the other, and the volume of
one causes a direct impact on the volume,
and thus the facility cost of the other.
In this symbiotic relationship, economic
theory states that maximum efficiency of
the total supply/treatment system would
occur if both were under a single owner-
ship and operation. But aside from the
institutional balance of power between the
two agencies and any savings that may come
about from closer coordination between
them, the separation of charges between
water and wastewater is more a matter of
equity than of efficiency.
This becomes clearer if specific cases
are examined. If municipal water supplies
are inexpensively priced, or at a flat
rate, consumption rises and a heavier
wastewater load enters the sewage treatment
plant. This directly causes increased
costs of sewage treatment, both capital and
operating costs. If sewerage charges are
billed to customers based on their winter
water consumption (as often happens), this
will tend to promote equity. However, if
sewerage charges are flat rate, low-use
customers help subsidize high-use cus-
tomers. When the use of one service
(sewer or water) is not charged on the
basis of volume of use, a distortion in
allocation of the service may occur.
When a program of water recycling is
implemented, some determination must be
made as to the allocation of costs for ad-
vanced wastewater treatment between the
sewage plant and the water supply agency.
What are the transfer costs? Should
125
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secondary treatment cost be allocated to
the sewage plant, and charged against
sewage treatment customers, while tertiary
treatment costs are charged to the water
supply agency and water users? How can
these costs be allocated equitably
(assuming the absence of a free market)
between agencies, whether the agencies are
separately owned and operated or depart-
ments of the same municipal government?
What happens if the water and wastewater
agencies do not serve identical popula-
tions? Should it matter in cost alloca-
tion if the higher treatment is required
by pollution regulations on the waste-
water as opposed to the water supply
agency? Economic research may help pro-
vide a formula for cost allocation that
will efficiently control the total system
and avoid stimulating suboptimization by
one part of the system.
WATER PRICING
The question of water pricing is
normally based on criteria such as the
following:*
a) To recover the costs of
operation;
b) To provide an acceptable
return on investment;
c) To maintain some type of
equity among classes of
consumers;
d) To encourage or discourage
certain uses of water by certain
customer categories, thus in-
fluencing levels and patterns
of demand.
Most water price structures are based on
the assumption that water is of uniform
quality. (Although some supply agencies
sell both raw and treated water, at differ-
ent prices, the differential usually is
close to the cost of treatment.) *Even
when water comes from different sources
having widely different costs, supply
agencies normally use average cost pricing
and deliver water to users of the same
*Hittman Associates, Inc., Price,
Demand, Cost, and Revenue in Urban Water
Utilities. Columbia, Maryland, 1970,
p. 1-1.
class (e.g., all in-city metered customers)
at the same price (or at the same rate
structure, although prices per thousand
gallons often vary as a function of quan-
tity used).
With water recycling, new problems
arise—particularly during the transition
period during which recycled water is pro-
duced but not yet distributed for potable
use. For example, the City of Colorado
Springs, Colorado, operates a conventional
potable water supply system and also
operates a tertiary treatment facility
generating two grades of nonpotable water:
an irrigation grade, sold for watering
lawns and golf courses; and a high-grade
industrial water suitable for use by power
plants and other industrial customers.
There exists a dual price structure. The
potable water is sold at a declining rate,
ranging from 90 cents per 100 cubic feet
to 45 cents per 100 cubic feet for amounts
exceeding 50,000 cubic feet per month.
Presumably this price structure for potable
water is necessary to cover fixed and
operating costs of the ^conventional water
collection, treatment and distribution
system. The nonpotable recycled water,
of either quality, sells for 22.5 cents
per 100 cubic feet. This lower price
nevertheless covers the costs of tertiary
treatment and distribution through separate
pipelines to the customers using nonpotable
water for irrigation and industrial
purposes.
A city faced with a water shortage
benefits from a situation such as that
described. That is, the potable supply
is saved for new residential users while
the nonpotable supply is used increasingly
to supply industrial and irrigation demand.
However, if the city does not face a
current water shortage but is developing
recycling to meet a potential need in the
future (as is the case with Colorado
Springs) the city could find itself in
destructive self-competition by providing
a cheaper substitute which reduces indus-
trial and irrigation demand for- its potable
water.
The problem is an economic one, re-
lating to the four pricing criteria listed
above. How does a city establish price
structures for its two or three grades of
water, to assure an equitable price for
each class of consumer, to assure efficient
126
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use of each grade, and still cover all
costs? The chosen structure must serve,
without sudden and unpopular price in-
creases to certain customer classes,
during the period in which reuse systems
are being developed and the relative
quantities of each grade of water produced
are shifting. Some economic research in
price policy is needed to guide the effi-
cient pricing of two or three grades of
water, any of which could be used by many
industrial or irrigation customers. Ulti-
mately, when the recycled water becomes of
potable quality, how are price structures
readjusted to maintain equity to all cus-
tomers, including those who have provided
a market for the recycled water during
its nonpotable period?
ECONOMIC ASPECTS OF ENERGY FOR RECYCLING
Although advanced wastewater treat-
ment and recycling technology varies (e.g.,
ion exchange, chemical precipitation such
as lime coagulation, ultrafiltration,
activated carbon filtration, reverse
osmosis, ozonation, chlorination) most
processes are energy intensive. That is
a significant amount of energy is used for
pumping through a series of tanks and
filters, for filter cleaning, for heating,
for calcining or recovering coagulation
and filter media, etc. Still more energy
is used for the manufacture of chlorine
and other necessary chemicals, and ozone.
A very preliminary indication of
energy consumption in a tertiary recycling
plant can be gained from operating cost
data for the two million gallons per day
Colorado Springs industrial water plant.
An operating cost breakdown for 1974
showed the following (capital charges
excluded):
Category
Labor
Energy
Chemicals
Maintenance
Percentage of
Operating Cost
If the energy used were all electrical, it
would represent about 1.70 kilowatt-hours
per thousand gallons of recycled water.
At the Colorado Springs commercial rate
structure, this would cost about 3.1 to 4.1
cents per thousand gallons.
Other tentative energy cost calcula-
tions can be found in SCS Engineers' 1973
report* which relates "utilities" costs of
operation to production of tertiary treated
effluent used in recreational lakes:
Utilities
Costs, cents
per 1,000
gallons
Lancaster W.R.P.
Santee Co. W.D.
0.86 (includes
secondary
treatment cost)
3.58
With the rapidly increasing cost of
energy and a growing recognition of its
limited supply, there is need for new
economic analysis of wastewater treatment
facilities and processes., Such analysis
would cover the energy used in the total
recycling system, including facility con-
struction, operation, and maintenance;**
treatment processes; chemical and ozone
manufacture; and pumping. By forecasting
increases in the cost of various forms of
energy, the analyst can influence selection
of water recycling technology that is
energy effective or cost effective or both.
Any energy analysis of reuse techno-
logy should of course include a comparison
*SCS Engineers, Demonstrated Techno-
logy and Research Needs for Reuse of
Municipal Wastewater. Long Beach, Califor-
nia, 1973, p. 105.
**For example, see Robert L.
Pillsbury, "Energy Conservation Through
the Architectural Design of Wastewater
Treatment Facilities," presented at the
47th Annual Conference, Water Pollution
Control Federation, Denver, Colorado,
October 9, 1974.
127
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with energy used in alternative ways of ob-
taining new water supplies. As Henry
Graeser points out:
In the Texas area, pipelines are
being built a hundred or more miles
in length. Compared to land costs,
pipeline costs and energy for trans-
basin diversion, advanced waste
treatment with planned recycling
is quite cost effective.*
IMPLICATIONS OF REUSE FOB DOWNSTREAM
WATER USERS
Except for disposition of sludge and
other waste matter extracted in advanced
wastewater treatment processes, recycling
eliminates the problem of sewage disposal.
In most regions of the country this will
be a real benefit; underground water
supplies and surface supplies as well will
no longer be contaminated by municipal and
industrial wastes. But it should be
pointed out that, in areas of the country
where water is in short supply the situa-
tion may be quite different. In these
areas, a large city may use a major por-
tion of a river's flow for municipal water
supply, so that consumptive use signifi-
cantly diminishes the quantity of down-
stream flow. If, as the city grows, it
relies on water recycling to provide addi-
tional water supplies, consumptive use
rises as a proportion of natural river
flow. Thus, downstream users will be cut
off from some portion of their accustomed
water supply, even though it might have
been water of inferior quality. Obviously,
this can cause grave economic and social
problems. What the consequences of this
are will depend upon the legal and insti-
tutional considerations of each particular
case. Some research into downstream
effects may help establish a basis for
equitable adjudication of disputes as well
as a basis for sound water resource
planning.
CONCLUSION
As this discussion has suggested, it
would appear that the principal question
with regard to recycled water is not so
much whether or not it will become a part
of municipal water systems, but whether
or not it can be efficiently and equitably
integrated into the economic and social
framework of existing systems. Without
attention to the problems discussed here
there is a possibility that the technical
capability for renovating wastewater will
outrun the capacity of the social and
institutional framework of which it must
be a part. Thus for the time being, where
recycled water can be made available at a
cost competitive with other water, every
effort should be made to begin to sub-
stitute it for conventional water at levels
farthest below human contact. This will
lengthen the life of present water supplies
and provide the time for a coordinated
research program to develop guidance in
the socio-economic areas outlined above.
This guidance for water resources policy
makers is clearly needed and is in the
public interest.
DISCUSSION
COMMENT: Mr. Dryden, Sanitation District
of L.A. County, Whittier, California. You
raised one question concerning what costs
are allocated to waste treatment and what
costs should go to the user. Most waste
treatment plants are now under NPDES permits
for discharge to the waters of the nation.
And we, at least, have tended to follow
the rule that the waste treatment facility
is responsible for all costs associated
with meeting those NPDES limits for dis-
charge, and that a water user who wants
additional treatment would then pay for
the additional treatment or the distribu-
tion system, and things like that, but that
there is a national break-point established
by our existing EPA-NPDES limit program.
*Henry J. Graeser, "Water Reuse—
Resource of the Future," presented at the
94th Annual Conference, American Water
Works Association, Boston, Massachusetts,
June 19, 1974.
128
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Charge to the Workshop
Albert C. Trakowski
Director, Office of Environmental Engineering
Environmental Protection Agency
Thank you for taking time out from
your busy schedules to come to the Uni-
versity of Colorado and participate in
this Workshop. This is the third in a
series of Research Needs Workshops spon-
sored by the Environmental Protection
Agency. The first Workshop was held at
the University of Illionois, Champaign -
Urbana, in July 1973, to develop research
needs for Recycling Municipal Sludges and
Effluents on Land. A second Workshop on
the Automation of Wastewater Treatment
Systems was held at Clemson University,
South Carolina in September 1974. This
Workshop is co-sponsored by EPA, the
Water Pollution Control Federation and
the American Water Works Association in
cooperation with the University of
Colorado. Again I would like to emphasis
that this Workshop is to define and
establish priorities for research needed
to develop confidence in the reuse of
municipal wastewater for potable pur-
poses. Although we realize that the re-
use of municipal wastewaters for various
other non-potable uses will probably in
most-instances be utilized first, we are
of the opinion that non-potable reuse
goals can be achieved effectively and
safely with today's water pollution con-
trol technology and therefore, do not
require a major research effort. On the
other hand, reuse for potable purposes
requires a long-range research program
in which we must embark on now in order
to effectively cope with the critical
water supply problems projected to face
this nation.
In the past, the Office of Research
and Development used several mechanisms
to obtain research needs from the user
community. However, because of a variety
of reasons, the research needs solicited
.by these methods were often inadequate
and could not be molded into an effective
research program.
Therefore, we have initiated Workshops
in order to invite the most knowledgeable
people in the United States, and in the
case of this Workshop, probably the World,
to analyze a particular research area and
develop specific research needs in order
to attain a specific goal. To repeat, our
specific goal during this Workshop is to
define research needs in order to develop
confidence in municipal wastewater reuse
for potable purposes.
Before arriving at this Workshop, a
packet of information was sent to each of
the invitees. In this packet, there is a
preliminary draft of a municipal wastewater
reuse strategy to which Mr. Frank Middleton
alluded to earlier in today's program.
This strategy outlines a reuse program on
which EPA is planning to embark on and is
ready to make a long-term commtrasnt.
Again I would like to emphasis that this is
a preliminary document,not an official EPA
policy, nor endorsed by the various orga-
nizations within EPA. It is, however, a
start at defining an Agency goal. Your
comments and suggestions on this document
will be most appreciative.
Your charge during this Workshop will be
to develop specific research needs in your
area of expertise so that EPA can accom-
plish the goal of potable reuse confidence.
The specific research needs and tasks that
you develop, will be coordinated and used
as building blocks to meet this goal.
129
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Each of you has been assigned to a
Workshop group session. Wa have made
assignments so that each workgroup will
have a manageable number of participants
so that there can be a good interplay of
information. If for some reason you
have not received a Workgroup assignment,
please see John English from EPA and he
will assign you to a Work group.
There are six Workgroups:
1. Wastewater Treatment for Potable
Reuse (Technology)
2. Treatment Reliability and Effluent
Quality Control for Potable Reuse
3. Health Effects of Potable Reuse
Associated with Inorganic Pollutants
4. Health Effects of Potable Reuse
Associated with Organic Pollutants
5. Health Effects of Potable Reuse
Associated with Viruses and Other
Biological Pollutants
6. Socio-Economic Aspects of Potable
Reuse
Wa have selected as Work group chair-
men, experts outside EPA in the respec-
tive fields. Their job is to stimulate
discussion, assimulate the research needs
developed, and report the Work group
findings back to the entire Workshop part-
icipants. To assist in the Work group
discussions, we have selected from within
EPA, experts in their respective scien-
tific fields to serve as Co-Chairmen. To
open discussions our Co-Chaimen have
developed a list of questions which in
their opinion require guidance, direction
and possible further research. Wa hope
that these questions can help guide each
Work group as they develop research needs.
Remember the purpose of this Workshop
is for EPA to learn from you. In your
work group, we expect lively debate, per-
haps polorization of discussion, since
many of you where selected to participate
in this Workshop because you represent
various schools-of-thought. Please
express your thoughts, so that the best
possible research needs can be developed.
From your Work group session we would
iijce. spacd£i0.,seseaj;efer ne@
-------
Guidelines for Developing Research Needs
If possible, specific research needs
that are developed should contain the
following information:
1. Statement of Specific Research
Need (can be one sentence)
2. Discussion
- Reason for Specific Research
Need
- Suggested approach to the
problem
- Suggested length of study
3. Priority
- High
- Medium
- Low
Sample Research Need
I. Development and demonstration of
treatment processes are needed to
ensure the removal of heavy metals
to levels suitable for potable reuse.
Discussion
Heavy metals are entering the muni-
cipal waste stream in even increasing
quantities. Research is needed to show
that these compounds can be effectively
removed. The major heavy metals that
should be addressed first are Ag, Cd, Cr,
Cu, Fe, Mu, Ni, Pb, Zn, Ba, Se, Hg, Co,'
Mo, As, and B. Sampling should be done
on a 24-hour composite basis every other
day. A one year study fulfills this re-
quirement. We feel that physical-chemical
processes should be explored first, since
it is our opinion that these processes can
ensure a greater treatment reliability
than the biological unit processes.
131
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WORKSHOP SESSION SUMMARIES
The objective of the Research Needs Workshop was to define and establish priorities
for research needed to develop confidence in the reuse of wastewater for potable
purposes. The following six Workshop Sessions were designed to achieve this objective:
1. Treatment Reliability and Effluent Quality Control for Potable Reuse.
2. Wastewater Treatment for Potable Reuse.
3. Health Effects of Potable Reuse Associated with Inorganic Pollutants.
4. Health Effects of Potable Reuse Associated with Viruses and Other Biological
Pollutants.
5. Health Effects of Potable Reuse Associated with Organic Pollutants.
6. Socio-economic Aspects of Potable Reuse.
The participants of each workshop group were selected to represent a broad spectrum
of technical expertise as well as a variety of organizational backgrounds. Summaries
of each of the six Workshop Sessions, including a list of participants, follow.
132
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WORKSHOP ON TREATMENT RELIABILITY AND EFFLUENT QUALITY
CONTROL FOR POTABLE REUSE
Chairman: Michael A. Bellanca., Virginia State Water Control Board
Vice-Chairman: John M. Smith, Environmental Protection Agency, NERC
Cincinnati, Ohio
1. INTRODUCTION
The research needs which will be
presented by the Task Force on "Treat-
ment Reliability and Effluent Quality
Control for Potable Reuse" will be
presented below in four parts:
Reliability Goals
Factors Affecting Plant Reliar-
bility and Effluent Variability
Design Considerations, and
Operational Controls
Research needs which are addressed
herein have been placed in one of the
four above categories. It is appar-
ent that there are grey areas and
some needs can fit in one or more
categories. These categories were
developed to provide a step by step
process which might lend itself to
development of suitable research
timetables. The questions which had
been formulated for discussion by the
Task Force were treated as starting
points and were not adhered to rigid-
ly. The research needs presented are
the result of a group concensus and
opportunity was allowed for minority
statements. In view of the time al-
lowed for development of these needs,
it was not possible to develop:
Approach to the Research;
Length of Study; and,
Projected Costs of the Proposed
Research.
The participants feel that technology
transfer is essential and that infor-
mation should be made available to
designers, systems managers, opera-
tors, etc. as soon as it becomes
available. This may well fit within
the current program of EPA.
2.
Several participants requested
that the record show that participa-
tion in the Workshop should not be
taken as representing tacit approval
of direct potable reuse. It was the
concensus that we were investigating
possible reuse in the future and that
we would be seeking to develop a
long-term research plan in the event
reuse becomes a reality. It was the
further concensus of the participants
that the present drinking water
quality standards were completely
inadequate for potable reuse.
IDENTIFIED RESEARCH NEEDS
A. Research Needed to Define Re-
liability Design Goals
1. Fail-Safe Reliability (High
Priority)
Need - To define fail-safe
reliability and determine
those factors or procedures
which will assure fail-safe
operation essential to the
production of a safe potable
water from domestic waste-
water .
Reason - Protection of public
health dictates that water
produced from reuse systems
is continually assured that
water of a questionable
quality can never enter the
distribution system.
2. Water Quality Standards for
Potable Water Reuse (High
Priority)
Need - Develop water quality
standards specifically for
potable water reuse.
133
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Reason - The currently appli-
cable drinking water stan-
dards were derived for raw
water sources of a different
character. Water sources
contemplated for potable re-
use systems contain a greater
variety of constituents which
are often present in concen-
trations much higher than
found in conventional raw
sources.
3. Determination of the Limits
of Variability Allowable for
Specific Water Quality Para-
meters (Medium Priority)
Need - To determine the allow-
able variability and thus the
allowable sampling or contin-
uous monitoring frequency re-
quired to insure adequate
process control and removal
of specific contaminants in
a reuse system.
Reason - Before successful
reliability design can be
achieved, it is necessary to
explicitly define the con-
taminant removal goals in
terms of allowable effluent
concentration and the accep-
able time varying ranges in
concentrations suitable for
domestic consumption. Dis-
tinction must be made for
contaminants that may result
in chronic and acute health
effects.
4. Interdisciplinary Project
Formulation (Medium Priority)
Need - Research is needed to
develop the form and financial
aspects of a reuse needs
study. Guidelines should be
developed for the use of state
and community authorities to
prepare minimum but compre-
hensive scopes of work for
feasible and engineering
studies of treatment alterna-
tives as a sound basis for
minimal budgeting.
Reason - When a move starts
in a community for addition-
al wastewater treatment the
custom is to have one or more
of the political leaders ask
a friendly engineer or com-
munity public works head for
a rough budget to accomplish
the wastewater treatment
needs. At this point it is
very important that the needs
be reviewed by a group of
interdisciplinary experts,
i.e., socio-economic, ecolog-
ical-environmental, environ-
mental engineer, planner,
political scientist, etc.
This group, selected jointly
by community and state
authorities, should develop
the scope of work needed to
conduct a feasibility study
and develop a budget for fur-
ther engineering and planning
studies.
B. Factors Affecting Plant Relia-
bility and Effluent Variability
1. Variability of Influent
Constituents (High Priority)
Need - To define the varia-
bility of specific influent
wastewater constituents as
it affects reliability of
unit process or overall
system removals.
Reason - The overall perfor-
mance of a reuse treatment
system will be affected by
the time dependent changes
in the mass flow (concentra-
tions x flow) of some in-
fluent wastewater consti-
tuents , and by shock loading
of toxic or treatment in-
hibiting substances when bio-
logical processes are em-
ployed. The changes in in-
fluent characteristics must
be known to permit knowledge
able selection of unit pro-
cesses and to predict unit
processes or system effluent
variability.
134
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2. Evaluation of Current Treat-
ment Technology (High
Priority)
Need - Research is needed to
determine the contaminants
present in domestic water
supplies today and to evaluate
the treatment processes cur-
rently in use to determine
if these contaminants can be
controlled, and at what
levels.
Reason - Contaminants of con-
cern are present in many do-
mestic raw water sources to-
day as a result of upstream
municipal and industrial
waste discharges. If the cur-
rent treatment technology is
evaluated as regards the re-
moval of these contaminants,
it will be possible to speed
development of potential re-
use schemes and process
trains.
3. Reliability of Domestic Waste
Systems and Domestic/Indus-
trial Waste Systems (High
Priority)
Need - There is a need to
determine the reliability of
systems which treat only do-
mestic waste and those which
treat combinations of domestic
and industrial waste.
Reason - There are a variety
of contaminants which can find
their way into waste treat-
ment systems. It is felt that
domestic sewage may provide
a medium much more amenable to
potable reuse and reliability,
and that it may be more easily
characterized in terms of its
constituents. Many systems
treat industrial as well as
domestic wastes and often the
industrial constituents are
either unknown or can be rap-
idly changed as a result of
in-plant changes and product
mix, thereby creating a po-
tential for stress of a pot-
able reuse system.
4. Effect of Recycle Stream.
Added Chemicals or Chemical
Reaction By-Products on Pro-
cess Variability and Relia-
bility (High Priority)
Need - To assess the impact
of recycle side-streams, ex-
traneous chemical additions,
and chemical reaction by-
products on variability of
unit process and total system
performance.
Reason - The specific end
products resulting from each
process used to treat domes-
tic wastewater for reuse as
a potable water may change
the form of the original con-
taminant or add new consti-
tuents that are unacceptable.
Chlorination, dechlorination,
ozonation, heat treatment,
among others, can under cer-
tain circumstances produce
additional unsafe consti-
tuents that must, in turn,
be removed to insure a safe
potable wat'er.
5. Risk Analysis of Acute and
Chronic Effects (High
Priority)
Need - Research into the acute
and chronic effects of ef-
fluent constituents and the
development of a "Risk
Analysis" procedure which
can be used to determine the
consequences of exposure on
the basis of concentration
and time, and the associated
cost to remove these con-
taminants to the desired
level with the desired degree
of reliability.
Reason - Some contaminants in
domestic wastewater are now
or will be identified as hav-
ing an acute or chronic
effect when present in vary-
ing concentration in reused
wastewater. The cost of re-
moving these contaminants in
reuse systems will vary de-
pending on the variability
135
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and reliability of removal
required. Effective design
and operation of reuse systems
dictates that removal goals
and permissible variation in
removal efficiency be estab-
lished.
6. Development of Technology
Assessment Program (High
Priority)
Need - To develop a program
which will:
(a) Evaluate new products as
they become available
in the market-place.
(b) Determine their impact on
potable reuse systems;
and
(c) Disseminate the informa-
tion to the water in-
dustry along with an
evaluation of suitable
treatment alternatives.
Reason - The rapid expansion
of technology will bring new
pollutants into the domestic
and/or industrial waste
stream. Reuse systems de-
signed at a certain point in
time may become rapidly out-
dated as these pollutants
enter the system and are not
amenable to the treatment
schemes in use.
C. Design Considerations
1. Reliability of Various Reuse
Schemes (High Priority)
Need - Once given the various
reuse schemes research will be
necessary to determine the
reliability of each and the
potential to continuously
achieve the water quality
standards applicable to pot-
able water reuse.
Reason - Any number of process
trains may be proposed for
processing water destined for
potable reuse. The reliabil-
ity of each system and its
capability to produce water
of an acceptable quality on
a continued basis will be the
criteria by which particular
systems may be chosen.
2. Variability of Influent
Constituents (High Priority)
Need - To define the varia-
bility of specific influent
wastewater constituents as
it affects reliability of
unit process or overall
system removals.
Reas on - The overall perfor-
mance of a reuse treatment
system will be affected by
the time dependent changes
in mass flow (concentration
x flow) of some influent
wastewater constituents, and
by shock loading of toxic or
treatment inhibiting sub-
stances when biological pro-
cesses are employed. The
changes in influent charac-
teristics must be known to
permit knowledgeable selec-
tion of unit processes and
to predict unit processes or
system effluent variability.
3. Equipment Development (High
Priority)
Need - Once specific reuse
systems are chosen they should
be researched to determine if
there is a need for types of
equipment not available at
the time; the needed relia-
bility of such equipment
should be determined and de-
sign specifications developed.
Reason - Available equipment
might not be suitable for
use in a proposed reuse
scheme. Equipment will have
to be developed for a specific
reliability in mind. Once
developed, specifications will
follow and should be made
available to design engineers
and systems managers.
136
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4. Investigation of Equipment
Failure Frequency and Impact
of Failure on Unit Process
and Total System Performance
(High Priority)
Need - Research is needed to
investigate the frequency of
failure of key pieces of
equipment in various unit
processes as a function of
service life. Also needed Ls
an evaluation of the impact
of equipment failure on unit
process and overall system
performance. The study
should include cost effective-
ness studies of alternate
back-up systems and should
outline the development of
contingency plans for over-
coming system failure.
Reason - One of the principle
sources of unreliable process
performance is equipment mal-
function. A firm knowledge
and understanding of the
causes of failure and expected
lifetime of key process equip-
ment will permit the design of
a more reliable system.
5. Minimum Plant Size (Medium
Priority)
Need - Research is needed to
determine the minimum size
plant amenable to reliable
operation for the production
of potable water for reuse.
Reason - One of the prime
reasons for poor plant relia-
bility is the plant operator.
It is felt that the poorest
operation is generally found,
for a variety of reasons, in
plants of small size and that
larger utilities stand a bet-
ter chance of attracting the
type of qualified personnel
necessary for reliable pro-
duction of potable water for
reuse.
6. Development of Indicator
Parameters for Continuous
Monitoring (High Priority)
Need - Research should be
undertaken to develop suit;-
able organic and biological
indicators which could be
automated and be used to
monitor effluents from potable
reuse systems. The resulting
input would be used in an ap-
propriate automatic feed-back
control system and would also
be used as decision logic to
divert sub-standard effluent
to holding basins for further
treatment or discharge to a
receiving stream.
Reason - The key to effluent
quality control in reuse
systems lies in the availa-
bility of suitable monitoring
systems to describe process
water quality of the influent
and effluent streams as well
as the inter-process streams.
Because of the larger number
of specific contaminants to
be monitored in the process
effluent stream and the pro-
jected high cost of analysis,
it is imperative that a few
specific indicator parameters
be identified that can be
correlated with the more
specific contaminants that
are of greatest concern from
an acute and chronic health
effects standpoint. The indi-
cator parameters should be
developed to replace such
gross tests as BOD5, CCE, etc.
D. Operational Controls
1. Essential Operation and Con-
trol Strategies (High
Priority)
Need - Research is needed to
determine essential operation
and control strategies.
137
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Reason - Potable reuse
systems are likely to be
very complex. In order to
assure consistent fail-safe
removal of all pathogens and
toxic substances it will be
necessary to have operational
and control procedures which
will give step by step in-
structions for the operation
of the various reuse schemes
and contingency for appro-
priate actions in the event
of specific unit process
failures.
2. Management and Organizational
Requirements (Medium Priority)
Need - Research is needed to
determine the types of manage-
ment organizations which can
effectively and reliably
assure operation of all pro-
cesses required to consistent-
ly remove all constituents
in wastewater that would
otherwise render it unsuitable
for potable reuse.
Reason - In order to assure
continuous reliable operation
of selected reuse systems, it
will be necessary to assure
the availability of adequately
trained and motivated person-
nel and to provide all neces-
sary back-up services (e.g.,
spare parts, electricians).
These requirements may vary
with the size of the facility,
the community served, and its
location in the United States.
3. Operator Capability and Com-
pensation Requirements
(Medium Priority)
Need - Research should be
undertaken to define the com-
plete staffing requirements
of reuse systems. The study
should include job descrip-
tions, required training, and
capabilities of all job cate-
gories needed for the effi-
cient and successful operation
of reuse systems. Emphasis
should be placed on special
staffing needs, such as
electricians, maintenance,
etc., that may be required
because of the higher level
of process control required.
Reason - Because of the high
degree of reliability re-
quired and the complexity of
reuse systems, successful
operation will require a much
higher level of operation and
maintenance than normally
provided for conventional
wastewater or water treat-
ment plants. In some cases
the special technology em-
ployed will require special
skills in the areas of opera-
tion, maintenance and analy-
sis. Consideration must be
given to the higher salary
requirements that are needed
to attract and maintain ade-
quately trained personnel.
4. Develop Indicator Parameter
Amenable to Continuous Moni-
toring (High Priority)
Need - Research should be
undertaken to develop suitable
organic and biological indi-
cators which could be auto-
mated and be used to monitor
effluent from potable reuse
systems. The resulting input
would be used in appropriate
automatic feed-back control
systems and would also be
used as decision logic to
direct sub-standard effluent
to holding basins for further
treatment or discharge to a
receiving stream.
Reason - The key to effluent
quality control in reuse
systems lies in the availa-
bility of suitable monitoring
systems to describe process
water quality of the influent
and effluent streams as well
as the inter-process streams.
Because of the large number
of specific contaminants to
be monitored in the process
effluent streams and the pro-
jected high cost of analysis,
138
-------
it is imperative that a few
specific indicator parameters
be identified that can be
correlated with the more
specific contaminants that
are of greatest concern from
an acute and chronic health
effects standpoint. The indi-
cator parameters should be
developed to replace such
gross tests as BODj, CCE, etc.
5. Preventive Maintenance -
Instrumentation (High
Priority)
Need - Research is needed to
develop and demonstrate pre-
ventive maintenance programs
for automatic process con-
trol and monitoring systems.
Research should also include
back-up systems for fail-safe
operation. Prime and back-
up systems will be interfaced
to provide automatic cross-
checking.
Reason - Treatment reliability
and fail-safe operation will
depend on the accuracy of the
automated instrumentation and
the operability of the control
and fail-safe systems. Pre-
ventive maintenance of these
systems will insure their con-
tinued accuracy and availa-
bility to perform the func-
tions for which they are de-
signed.
6. Research to Determine Optimum
Sampling Frequency (High
Priority)
Need - A study is needed to
determine the number and fre-
quency of effluent samples
required for various waste-
water constituents to insure
adequate process control and
effluent product quality.
Examination should be given
to the frequency required
for contaminants identified
as causing both chronic and
acute health, effects.
Reason - Some parameters of
reused wastewater quality
will require more frequent
monitoring than others.
Some must be monitored con-
tinuously, while others may
be monitored less frequently
depending on the potential
health risk or toxicity
effects. Cost effective
operational control requires
optimization of sampling and
analysis to minimize analy-
tical costs while assuring
that quality goals are met.
7. Development and Demonstration
of Preventive Maintenance
Programs for Process Equipment
(High Priority)
Need - Development and demon-
stration of preventive main-
tenance programs are .needed
to extend the lifetime and
increase the reliability of
major or key equipment em-
ployed in reuse systems. The
preventive maintenance pro-
gram should include the
development and preparation
of operation manuals, needed
spare parts, inventories,
and the identification of in-
spection procedures and tech-
niques to reduce down-time
due to maintenance related
equipment failure.
Reason - Successful implemen-
tation of effective preven-
tive maintenance techniques
and procedures can- potentially
reduce maintenance related
down time of critical pro-
cess equipment, thereby in-
creasing system reliability.
Workshop Participants:
Michael A. Bellanca - Chairman, Virginia
Water Control Board, Richmond, Virginia.
Paul D. Haney, Black & Veatch, Kansas
City, Missouri.
R. E. Leffle, Camp, Dresser & McKee,-Inc,,
Boston, Massachusetts.
139
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William Long, EPA, Washington, D.C.
Henry J. Ongerth, California Department
of Health., Berkeley, California.
Joseph Roesler, EPA-NERC, Cincinnati, Ohio.
John M. Smith - Vice Chairman, EPA-NERC,
Advanced Waste Treatment Laboratory,
Cincinnati, Ohio.
Sheldon 0. Smith, Environmental Conserva-
tion Programs, Mineola, New York.
Michael J. Taras, American Water Works
Association, Research Foundation,
Denver, Colorado.
Vern W. Tenney, EPA, San Francisco,
California.
Stephen W. Work, Denver Water Department,
Denver, Colorado.
Robert L. Wortman, Oklahoma State Depart-
ment of Health, Oklahoma City, Oklahoma.
Darwin Wright, EPA, Washington, D.C.
DISCUSSION
QUESTION: Moderator Convery, AWTRL,
U.S. EPA, Cincinnati, Ohio. I've got one
question. Did your committee address the
difference in reliability requirements for
acute versus chronic materials? This came
up in our workshop and we certainly were
very interested in preventing the periodic
discharge of acute toxicants. However, we
felt that a less stringent standard might
possibly apply for chronic toxicity- Was
this addressed at all in your workshop?
RESPONSE: Mr. Bellanca, Virginia Water
Control Board, Richmond, Virginia. It was
only addressed in the sense that we were
speaking of the need for monitoring and
that, for example, the requirements for
acute monitoring would be much more strin-
gent than those for the chronic, as you
mentioned. We did not take into considera-
tion the fact of the discharge into the
receiving streams, but we did take into
account proof of acute and chronic health
effects just in terms of the reliability
because we realize that they will affect
the reliability to certain degrees. That
was one of the research needs that we
identified, but not in the sense of a
discharge to receiving waters. That was
your question.
COMMENT: Moderator Convery, AWTRL,
TJ-,8-, E?A? Cincinnati, Ohio. I am refer-
ring to the. standard of performance assoc-
iated with contaminants considered to have
acute toxicity versus those which are
said to have chronic toxicity-
RESPONSE: Mr. Bellanca, Virginia Water
Control Board, Richmond, Virginia. This
is one of the needs which we identified
as requiring some research. That is im-
plicit in one of the recommendations that
we made.
COMMENT: Mr. Roesler, EPA-NERC,
Cincinnati, Ohio. I would like to say,
in regard to these acute and chronic
materials, we decided there should be
some work in determining the optimum moni-
toring frequency for certain types of
pollutants. In a sense, this would keep
us up to date on what is coming out of
the plant. For certain pollutants, of
course, we felt that because of the
nature of the pollutants and their
health effects, people could tolerate
relatively high levels of them without any
adverse effects. So, for certain pollu-
tants, perhaps a daily monitoring would
be sufficient. With other types of pol-
lutants, we would almost have to have in-
stantaneous and continuous monitoring,
A good example of this is pathogens.
COMMENT: Dr. Dean, AWTRL, US-EPA,
Cincinnati, Ohio. The program you set up
sounds like a very good food engineering
plant for making excellent water. I like
your fail/safe program. I just want to
know why such a program shouldn't also
apply to any water supply that is pol-
luted, because the same pollutants are
present in concentrations which are not
significantly less. By that I mean less
than ten percent of what you've got in
wastewater. So there must be a reason
why it is not necessary to have a fail/
safe water supply but it is necessary to
have fail/safe reuse water. But the
reason escapes me.
140
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RESPONSE: Mr. Bellanca, Virginia Water
Control Board, Richmond, Virginia. That's
a very excellent comment. It was one that
was considered at some length by the com-
mittee. As a matter of fact, Denny Parker
and I had a long conversation over break-
fast this morning on that same subject.
It is our feeling that as the requirements
for potable reuse become a little bit more
widely disseminated, you might begin to
see some changes in attitudes with respect
to wastewater and water treatment.
We did take this into consideration, but
in a different manner: by looking at the
present-day raw water system, such as EPA
is doing now, to determine whether or not
these contaminants are reduced through
conventional treatment. It is in this
sense, that we make our recommendation.
But I do agree that we should be looking,
along the same lines, at the fail/safe
reliability of our present systems. One
key problem appears to be the motivation
of the people behind the systems, and to-
day that is seriously lacking.
COMMENT: Shuval, Director, Environ-
mental Health Laboratory, Jerusalem,
Israel. I fully support Dr. Dean's point,
and I think, since this has come up con-
tinuously through the meeting, that the
editors of the final report would be well-
advised to state in the preamble that many
of the treatment reliability and effluent
quality control recommendations, toxicolog-
ical study recommendations, and treatment
technolosy should apply as well to any
form of indirect wastewater reuse. It was
not the intention of the people sitting
here to imply that this technology is re-
stricted solely to direct or overt reuse.
I think this is something that is going
to come up constantly, and I think that
Dean's point should be expressed by the
editors of the final report, although it
may not have been said in any particular
document.
I told you that a good example of this
was the Amsterdam meeting where we actually
changed the name of the meeting when we all
agreed that everything we said there ap-
plied just as much to drinking Rhine River
water, which was fifty percent wastewater,
as to the effluents at Rotterdam which is
a hundred percent wastewater and might be
diluted fifty percent with some other
water.
So I think that this is an editorial
point that should go all the way through
the report.
RESPONSE: Mr. Bellanca, Virginia Water
Control Board, Richmond, Virginia. Very
well taken.
COMMENT: Mr. Spitzer, AWWA Research
Foundation, Denver, Colorado. You men-
tioned the need for research, for example,
into maintenance and all this fancy equip-
ment. Actually, I think we've already
got that technology through NASA, and the
petro-chemical industry. Instead of dup-
licating their research we ought to do a
little borrowing.
RESPONSE: Mr. Bellanca, Virginia Water
Control Board, Richmond, Virginia. That's
a very good point, Mr. Spitzer. Of course,
I remember it was said in the very begin-
ning that not all of us know the complete
availability of things. It is comments
such as yours that would help to identify
where there are needs such as this and
where there are techniques available.
COMMENT: Mr. McCabe, Criteria Develop-
ment Branch, Water Supply Research Lab.,
EPA, Cincinnati, Ohio. I think the water
industry and the state regulatory agency
have really done what Mr. Dean suggested.
The great bulk of water supplies are rather
small and use groundwater supplies. In
the design of these supply systems there
is really little opportunity for problems.
You know, you set your well for ground
water and what can happen? So we really
have developed some fail/safe concepts,
because we don't allow small communities
to go on surface water supplies. Ground
water systems are more reliable. Admit-
tedly, we do get some outbreaks. But at
least we have tried not to have complex
systems in small towns.
COMMENT: Mr. Ongerth, California
Department of Health, Berkeley, California.
I think I made the point earlier that
three-quarters of my efforts are in con-
trolling domestic water supply. I em-
phatically agree with what is being said,
and I think we are wasting time to continue
beating this horse. The waterworks indus-
try generally understands the need for
greater reliability, and certainly the
regulatory people are focused on this all
the time. Let's to on to another point.
141
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QUESTION: Mr. Gallowin, National Bureau
of Standards, Washington, B.C. I wonder
if you had addressed in your considera-
tions a simplistic approach of meeting
your requirements for whatever concentra-
tions may be allowed through a simple
blending operation of reprocessed waste-
water with "good" water blended at some
point. Or is that implicit in some of
what you have presented?
RESPONSE: Mr. Bellanca, Virginia Water
Control Board, Richmond, Virginia. Mr.
Gallowin, we did not address the actual
scheme itself since we did not know which
ones to consider. That we felt was the
work of another group. That is a possi-
bility, yes.
142
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WORKSHOP ON RESEARCH NEEDS FOR TREATMENT FOR POTABLE REUSE
Chairman: Franklin D'. Dryden,
County Sanitation Districts of Los Angeles County
Vice-Chairman: Carl A. Brunner, Environmental Protection Agency, NERC
Cincinnati, Ohio
INTRODUCTION
The work group on treatment found it
difficult to discuss the assigned topic
without benefit of the views of the relia-
bility, quality control, and health effects
work groups. However, with full recogni-
tion that we were working in a vacuum, the
group proceeded to identify ten specific
research needs related to treatment for
potable reuse. The highest priority was
assigned to the task of assembling and
operating demonstration facilities of from
0.5 to 1 mgd scale capacity in different
parts of the country. These would utilize
four treatment trains, as depicted in
Figure 1, and their variations. These
treatment trains should be applied to in-
dustrial wastewaters, domestic wastewater,
and substantially polluted river waters.
As elaborated in the detailed description
of needs, these facilities would be used
to characterize the efficiency of perfor-
mance of each treatment train with regard
to relevant quality parameters, costs,
energy requirements, by-product production,
residual waste disposal problems, and over-^
all reliability.
The other areas of high priority in-
clude developments of the use of chemical
oxidants for the removal of trace organics
and effective fail-safe disinfection
systems, which do not create hazardous by-
products and which will provide residuals
in water distribution systems. Where time
allowed, rough cost estimates were pro-
vided for some of the following needs. Al-
though all of the needs were believed to
be important and part of a comprehensive
program, which is estimated to cost about
$5 million per year for the next ten years,
priorities have been assigned to indicate
the relative importance of the various
needs or portions thereof.
1. TREATMENT CHARACTERIZATION STUDIES
A. Characterize Effectiveness of Al-
ternative Treatment Systems for
Removal of:
Priority
a.
b.
c.
d.
e.
f .
g-
h.
Organics
Trace metals
Nitrogen
Bacteria
Viruses
Parasites
Aesthetics
Suspended solids/
turbidity
High
Medium
Medium
Medium
High
Medium
Low
High
With Regard To:
a.
b.
c.
d.
e.
f.
Discussion
Efficiency
Energy requirements
Costs
By-products
Reliability
Residual wastes and
disposal
solids
The identification of the specific
pollutants in the final product and the
characterization of the removals perfor-
mance of the individual processes within
the treatment system are needed to inter-
pret the results of health effects studies.
In addition, knowledge of individual pol-
lutant characteristics and the capability
of the individual processes to remove them
will help establish intelligent source
143
-------
Cl,
FIGURE 1.
I. RAW WASTE
LIME PRIMARY
TREATMENT
^•<-C°2
PHYSICAL
CHEMICAL
NITROGEN REMOVAL
i
CARBON
ADSORPTION
|
MIXED MEDIA
FILTRATION
^
CHEMICAL
OXIDATION
t
EFFLUENT
V
>
ARIOUS POTABLE WATER TREATMENT PROCESS TRAINS
II. RAW WASTE III. RAW WASTE IV. RAW WASTE
PRIMARY
TREATMENT
^
AERATION
BASIN
t
SECONDARY
SEDIMENTATION
t
LIME
TREATMENT
*«*-c°;
MIXED MEDIA
FILTRATION
^
PHYSICAL CHEMICAL
N REMOVAL
^
CARBON
ADSORPTION
, CH
&
PRIMARY
TREATMENT
i
COMBINED
CARBON AND
NITROGEN REMOVAL
^
SECONDARY
SEDIMENTATION
*
LIME
TREATMENT
3OH_^^^_C02
CARBON
ADSORPTION
t«*-Cl2
CARBON
ADSORPTION
i
MIXED MEDIA
FILTRATION
LIME TREATMENT
OR
ACTIVATED SLUDGE
^
NITRIFICATION
*
SEDIMENTATION
^^_CH,
DENITRIFICATION
i
SEDIMENTATION
*
CARBON
ADSORPTION
*
MIXED MEDIA
FILTRATION
REVERSE ^ OSMOSIS ^ X
CHEMICAL
OXIDATION
CHEMICAL
OXIDATION
CHEMICAL
OXIDATION
VARIATIONS
(many possible)
RESIN SORPTION
FOLLOWING CARBON
REVERSE OSMOSIS
TWO STAGE LIME
FOR SOFTENING
ION EXCHANGE
ULTRAFILTRATION
FOLLOWING FILTRA-
TION
DISTILLATION
INCLUDING IN EACH
EFFLUENT STORAGE
DISINFECTION
MULTIPOINT COAGU-
LATION ADDITION
KEY
C12 = Chlorine for
monia removal
C0? = Carbon dioxide
for recarbona-
tion
fll rUl — lUTat-Vtonnl -F/^v
EFFLUENT
EFFLUENT
EFFLUENT
denitrification
(or other N-
organic)
-------
control programs as well as potentially
lead to process improvement and new pro-
cess development. The data from the
characterizations will also provide know-
ledge of process performance variability
and reliability. The data from the
characterization also may identify key
constituents and variables for indicator
monitoring and process control.
Without the characterization studies,
widespread application of direct reuse is
unlikely. Finally, improved process
characterization will aid in developing
design and cost data for selection of
cost effective systems in specific site
applications.
B. Alternative Treatment Systems
Deserving Evaluation: (High
Priority)
Based upon experience to date, it
is believed that the four treatment
trains shown on the attached figure
hold the potential for reliably pro-
ducing potable quality water from raw
(primarily domestic) wastewater.
There is a need to evaluate these
systems in terms of the parameters
listed under 1A above. The intensive
characterization period will require
at least three years, plus any further
time needed for evaluation of health
effects. Each facility should be de-
monstrated on at least a 0.5 mgd scale
to establish performance credibility.
They should be applied to municipal
wastewaters, domestic wastewaters, and
polluted river water.
System I is an independent physi-
cal-chemical process. System II is
a secondary-tertiary process. System
III is similar to System II except
that the bulk of the nitrogen is re-
moved in the initial one-step biologi-
cal treatment stage. System IV is an
integrated chemical-biological treat-
ment system. Rough cost estimate
(1975 dollars): $3,000,000 construc-
tion cost per system. Analytical and
operation costs (excluding health
effects): $800,000 per year per
system.
2. DEVELOPMENT AND/OR IMPROVE SUITABLE
DISINFECTION PROCESSES AND EVALUATE
THESE TECHNIQUES TO UNDERSTAND THEIR
BENEFITS AND ADVERSE IMPACT:
Discussion
Disinfection is a mandatory require-
ment for potable wastewater reuse to in-
sure protection of the public from infec-
tion. Unlike health hazards resulting
from chronic toxicants, where the effect
results from low-dose, long-term exposure,
the impact of pathogenic organisms cannot
always be moderated by dilution or blend-
ing. This requires the disinfection pro-
cess to have a higher degree of control
and reliability with essentially no allow-
ance for short-term process failure. The
generation of toxic by-products during
the disinfection process, notably, but not
restricted to, chlorine, is reducing the
options for providing disinfection in a
safe manner and possibly creating the re-
quirement for new alternative processes.
Many of the specific research requirements
are shared by those in water supply and
effluent treatment as well as those inves-
tigating oxidizing processes for trace
organic removal. These overlapping con-
cerns further justify the high priority
placed on this research need.
Four subcategories were identified to
better direct the research needed in this
area. Their relative priorities were also
defined.
A. Examine the By-Products of all
Candidate Disinfection Processes:
(High Priority)
Various techniques for water dis-
infection, especially chlorination,
produce reaction by-products of known
or suspected adverse health impact.
These by-products must be identified
for all candidate processes so that
the consequences of the processes'
use can be fully evaluated and under-
stood. First priority should be given
to chlorine, ozone, and ultraviolet-
catalyzed ozone processes, but other'
alternative disinfection processes
should not be ignored, especially if
discouraging results are obtained for
the above processes. Alternative
processes could include the use of
bromine, chlorine dioxide, ultraviolet
145
-------
light, ionizing radiation, and other
oxidizing processes. This program
could be most effectively conducted
in close coordination with health
effects research studies.
B. Identify Safe Residual Disinfec-
tion Alternatives: (High
Priority)
Known unit processes that combine
disinfection with trace organic re-
duction or removal do not impart a
disinfection residual to the product
water. A residual appears necessary
for product assurance and public ac-
ceptance. The use of chlorine for
this purpose may be acceptable if the
trace constituents that are the pre-
cursors for toxic by-products are
eliminated or reduced to an accept-
able level. The identification of an
alternative process, possibly involv-
ing new technology, appears worth-
while to raise confidence in the
safety of the product water. This
research need is especially shared
with those in water supply research
and requires close coordination and
transfer of technology.
C. Identify Best Point(s) for Appli-
cation of Disinfectant in Treat-
ment Chain: (Medium Priority)
The utilization of a disinfection
process for a dual purpose (use of
ozone for disinfection and trace or-
ganic removal) may make it desirable
to place it earlier in the treatment
chain. Due to the protection by
solids, this reordering may diminish
the disinfection effectiveness at the
expense of increased organic removal.
Any efforts on the reordering of such
dual purpose processes should include
verification that no significant re-
duction in disinfection is created.
This evaluation should also include
an evaluation of the processes' sus-
ceptibility to shock loading or pro-
cess failure in its new location.
D. Improve the Application of Dis-
infection Technology: (Medium
Priority)
Disinfection, as commonly prac-
ticed (primarily chlorination), can
be significantly improved through the
3.
application of improved mixing and
contact technology. This effort
may be insuring that the technology
transfer of new methods are provided
to those responsible for wastewater
reuse. A relatively small continuing
research effort is warranted to in-
sure the principles developed for
chlorination are appropriate or need
improvement when alternative disin-
fectants are used.
NEED TO IDENTIFY AND VALIDATE INDI-
CATORS OF SYSTEM PERFORMANCE FOR:
a. Quality Control
b. Process Control
Priority
High
High
Discussion:
This need is considered high priority
because item (a) is necessary to permit
performance monitoring without an over-
burdensome analytical load, and item (b)
is necessary for reliable and cost-effec-
tive operation.
Physical, chemical, or biological
measurements which are easy to make rou-
tinely and which are predictive of incipi-
ent contaminant penetration are necessary.
In addition, techniques to measure process
operating parameters and control strate-
gies to permit a manipulation of these
parameters in response to input or output
variations are necessary.
Examples might include TOC monitoring
of carbon columns; turbidity, trace metal
and chlorine residual for virus inactiva-
tion, pH control for trace metal reduction,
indicator organisms more resistant to dis-
infection than viruses, etc.
Laboratory analysis of pilot plant
operations for three years and 40 man-
years .
4. NEED FOR ADEQUATE PROCESSES FOR TRACE
ORGANIC REMOVAL:
Discussion:
Present technology for organic re-
moval results in product waters containing
-------
approximately 1 to 2 mg/£ total organic
carbon. Although it has not been deter-
mined that there is a health hazard to
this organic residual, there is likely to
be a need to remove the materials to some-
what lower levels. Specific potential
methods for removal include:
a. Chemical oxidation - including
ozone and/or hydrogen peroxide
with and without ultraviolet acti-
vation and others.
The-first step should be lab-
oratory scale testing of the
methods on appropriate feed water
to determine technical feasibili-
ty. A one-year effort at $150,000
is reasonable. Pilot and demon-
stration work would follow for
feasible methods. Cost for pilot-
ing each successful method would
be approximately $100,000. (High
Priority)
b- Resins - Small scale testing of
appropriate resins in continuous
contactors is needed. Approxi-
mate research cost is $100,000.
Any successful candidates should
be pilot tested to determine long-
term effects. Approximate cost
would be $100,000 per pilot.
(Medium Priority)
c. Membranes - Small scale continuous
testing is the minimum required.
Minimum cost is $150,000. Pilot
testing of promising systems would
cost about $150,000 per pilot.
(Medium Priority)
d. Volatile stripping — Initial test-
can be carried out as a $50,000
laboratory effort. If pilot test-
ing is indicated, a study could
be conducted for $250,000.
e. Hew methods - Ideas for removing
the trace organics should be
solicited from appropriate sources.
A feasibility study of a new
method can probably be carried out
for $100,000. (High Priority)
5. NEED EFFECTIVE AND ECONOMICAL PRO-
CESSES FOR REMOVAL OF SELENATES,
ARSENATES, CHROMATES, AND MOLYBDATES:
Discussion:
Although processes are available for
removing many of the trace metals of con-
cern from wastewater, the above ions are
not well removed by most of the processes
common in AWT. There is need for further
study of possible removal processes to
either remove these with other materials
in the AWT process train or to permit
pretreatment to enhance their removal.
Effort: 2 man-years Cost: $100,000.
(Low Priority)
6. EVALUATION AND IMPROVEMENT OF PRO-
CESSES FOR DEMINERALIZATION IN ORDER
TO
a. Reduce costs.
b. Reduce energy requirements.
c. Utilize beneficial side
effects.
AND IN PARTICULAR TO DEMONSTRATE ION
EXCHANGE IN RENOVATION SYSTEMS:
Discussion: '
In some areas of the nation, the
salinity of renovated water can militate
against its use, not only for domestic
(potable) reuse but also for lower grade
uses in industry or agriculture.
The salinity can arise from the ini-
tial salinity of the natural water, from
saline inputs during use, and from infil-
tration of saline groundwater into the
sewage system.
In systems where new water is of low
salinity and makeup exceeds 50%, salinity
should not be a problem. However, in a
large system, it may not be geographically
feasible to redistribute the saline-reno-
vated water equally over the whole system
so that local concentrations may rise. In
such cases, partial desalination to scalp
a proportion of the' salts may be an econo-
mic tool for water management.
Desalination, utilizing ion exchange
resins, reverse osmosis membranes, or dis-
tillation will also have beneficial effects
147
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on the removal of the other pollutants in
the treatment train. For example, toxic
metals, some organisms, and nutrients in-
cluding nitrates may be removed in the
course of desalination. Reduction of
hardness of renovated water may be a
benefit for domestic use.
Suggested Approach;
Test on laboratory scale new demin-
eralization processes with potential for
significantly reducing costs or energy
requirements using waters from operating
treatment plants. Demonstrate the most
cost-effective ion exchange technology.
Probably two to three years. Labora-
tory scale, increasing to 10,000 gpd pilot
plant where justified. Demonstration of
the best techniques: $750,000. Demonstra-
tion of ion exchange: $750,000. (Low
Priority)
7. NEED TO EVALUATE STORAGE STRATEGIES
WITH RESPECT TO AWT AND POTABLE REUSE:
Discussion:
Two essential factors in reuse -
quantity and quality - are impacted by the
concept of storage.
With respect to quantity, storage
again reflects upon two different needs,
that within the plant and that before or
after the reclamation facility- In most
cases, steady state performance can be ex-
pected from the reuse plant with its abil-
ity to choose and withdraw required amounts.
Flow equalization can reduce diurnal and
seasonal flow fluctuations if needed.
Within the plant, however, storage
appears essential before filtration and
perhaps carbon treatment or demineraliza-
tion because of erratic recycled streams.
In-plant ballast ponds serve a dual pur-
pose as an emergency holding facility for
bypassed flow and as buffering capacity.
Post plant ponds may serve as a buffer
for required water demands. Covered stor-
age is essential for quality control.
In terms of quality, storage can
average out concentration peaks before
the AWT plant and allow detention time
to reduce biological contaminants.
If a poor quality effluent is the
feed to the reclamation plant, storage
may or may not enhance quality. In some
cases additional pretreatment may be
necessary. Extended storage may result
in growth of undesirable organisms.
The main concern is finding the least
costly method of providing the storage
since the benefits of flow equalization
and product protection are clearly evi-
dent.
The research ranks low in priority
and is being studied in the entire AWT
and sewage treatment field. It deserves
research funding but perhaps not in terms
of potable reuse.
A good part of the evaluation can be
performed on paper with only limited test-
ing to ascertain whether there are pro-
blems associated with any particular stor-
age mode.
8. DEVELOP AND DEMONSTRATE LOW-ENERGY
NITROGEN REMOVAL PROCESSES:
Discussion;
Nitrogen removal will be required in
the treatment of wastewater for potable
reuse. Currently available physical-
chemical and biological nitrogen removal
processes use large amounts of energy to
remove a substantial fraction of the
nitrogen present in wastewater. Combin-
ing the processes of removing carbona-
ceous and nitrogenous materials in a
single-stage biological reactor offers
the most promise of removing 70- to 90% of
the nitrogen present and, at the same time,
substantially reducing the total energy
expended. In this process, the organics
present in the wastewater supply the
source of carbon for denitrification and
eliminate the offsite energy consumption
in methanol production. Other means of
reducing energy consumption in nitrogen
removal processes should be investigated.
148
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Suggested Approach:
Construct a 100,000 gallon/day demon-
stration plant and operate for one year.
Seek innovative low-energy alternatives
for bench scale testing. Cost of project:
$500,000. (Low Priority)
9. DEMONSTRATE STABILIZATION/RECOVERY/
DISPOSAL OF RESIDUALS RESULTING FROM
ALTERNATIVE TREATMENT SYSTEMS DELIN-
EATED IN IB: (High priority overall
but low priority specifically for
potable reuse)
Discussion;
Research is to insure the availability
of adequate and economically viable control
options for the accumulated residuals ema-
nating from treatment processes related to
potable reuse. The problem area is not
unique for the potable reuse problem but
necessarily is a guidelines factor for
eventual implementation of specific treat-
ment schemes.
Approach:
1. Determine nature of residuals
emanating from alternative treat-
ment systems.
2. Nominate methods for controlling
residuals.
3. Verify economic viability through
engineering scale demonstrations
of control methods.
4. Make sure land stabilization al-
ternatives are considered.
5. Apply residual control criteria
to overall viability criteria of
alternative treatment systems.
Length of Study;
Major activity requiring time alloca-
tion is demonstration. This should be
long enough to assess residual variation
and control technology stabilization on
the order to two to four years. Costs:
Pilot studies in conjunction with alterna-
tive treatment systems in the amount of
$250,000 per year per pilot facility.
10. AN .EVALUATION OF THE CHANGES IN
WATER QUALITY RESULTING FROM STORAGE
AND MOVEMENT OF TREATED WASTEWATERS
THROUGH THE GROUND:
Discussion;
Several of the present and potential
systems for treatment and planned reuse
of municipal wastewaters for potable water
supply involve percolation or injection
of the treated water into groundwater
aquifers. The storage time, movement, and
intermingling with naturally occurring
groundwaters may result in substantial
improvement in quality and safety of the
water. However, information on the kinds
and extent of improvement, which may re-
sult, is lacking. Research is needed to
determine what levels of improvement can
be expected and to establish what charac-
teristics of injected or percolated waters
lead to maximum improvement in water
quality and minimum reduction in the per-
meability of the groundwater aquifer.
Workshop Participants:
Dolloff F. Bishop, U.S. EPA, National
Environmental Research Center,
Cincinnati, Ohio.
James R. Boydston, U.S. EPA, Corvallis,
Oregon.
Carl A. Brunner - Vice-Chairman, EPA/NERC,
Advanced Waste Treatment Laboratory,
Cincinnati, Ohio.
John J. Convery, AWTRL, U.S. EPA,
Cincinnati, Ohio.
Franklin D. Dryden - Chairman,
Sanitation District of L.A. County,
Whittier, California.
Don Felke, Tertiary Plant Foreman,
Colorado Springs, Colorado.
Daryl Gruenwald, Wastewater Treatment
Superintendent, Colorado Springs,
Colorado.
Carl Hamann, Cornell, Howland, Hayes &
Merryfield, Inc., Reston, Virginia.
Richard D. Beaton, Denver Water Department,
Denver, Colorado.
149
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Denny S. Parker, Brown & Caldwell, Walnut
Creek, California.
Stanley Smith, Water Division, EPA,
Denver, Colorado.
Albert Soukup, U.S. EPA, Denver, Colorado.
Richard L. Woodard, Camp,. Dresser & McKee,
Inc., Boston, Massachusetts.
DISCUSSION
COMMENT: Mr. Spitzer, AWWA Research
Foundation, Denver, Colorado. I am a
little bit disappointed because you have
given aesthetics a low priority. Take,
for example, taste and odors. We have
trouble selling some of our products now
because of taste or odors, and we cer-
tainly haven't solved these problems. If
we have trouble selling something that is
taken from a rather good source, after you
go through all of the other removals (and
they are certainly important), if you
can't sell it, there is no use going
through that. I think that should cer-
tainly be rated high.
RESPONSE: Mr. Dryden, Sanitation Dis-
trict of L.A. County, Whittier, California.
We recognized that that might cause some
controversy. I think it reflects the gen-
eral confidence of the group that by the
time we went through the treatment chains
that we are talking about, the research
problem of taste and odors was not going
to be high priority, and that these systems
were in fact, capable of handling the taste
and odor problem. We do think it is a pro-
blem that needs to be looked at. Should
it turn out to be a real problem, obviously
it would have to be given attention. But
I think the low priority simply reflects
the feeling that the process chains that
are described herein can actually handle
the components that would contribute to
the taste and odor problem.
COMMENT: Mr. Jack Glennon, U.S. Army
Medical Research Development Command,
Washington, D.C. Another thing is that
the priorities on this first page more or
less describe the level of effort that
would be required in the validation study.
In other words, more samples should be
taken for organics and less for taste and
odor. That being a relatively easy
parameter to measure, you can get better
reliability on it with less effort in-
volved in the sampling.
QUESTION: Mr. Robert G. Tardiff, EPA/
NERC, Cincinnati, Ohio. You have discus-
sed the removal of selenates, arsenates,
chromates, and molybdates. I would be
interested to know why you restricted
that to one valence form.
RESPONSE: Mr. Dryden, Sanitation
District of L.A. County, Whittier, Cali-
fornia. Would Dick Woodard like to speak
to that?
RESPONSE: Mr. Richard L. Woodard, Camp,
Dresser & McKee, Inc., Boston, Mass. I
think the feeling was that lower valence
forms of these materials are much more
readily removable by conventional pro-
cesses than the higher valence forms.
COMMENT: Mr. Tardiff, EPA/NERC, Water
Supply Research Laboratory, Cincinnati,
Ohio. I don't know how good that is go-
ing to be, though, if the other valence
forms are more toxic. If the other val-
ence forms are more toxic, what good is
it going to do to remove arsenate if you
have arsenite left behind? Is that what
you said here?
RESPONSE: Mr. Woodward, Camp, Dresser &
McKee, Inc. Boston, Mass. No. I said
you can take out arsenites fairly readily
with some of the processes that are listed
here.
COMMENT: Mr. Tardiff, EPA/NERL, Cin-
cinnati, Ohio. Down to the real low
levels? At the present time, the effi-
ciency of removal is not that great. The
kinetics are such that you don't remove
it down to the part per million level.
RESPONSE: Mr. Woodard, Camp, Dresser &
McKee, Inc., Boston, Mass. Of course,
it depends on where you start. Only in a
very few situations are these materials
present in relatively significant concen-
trations. This normally occurs in certain
natural groundwaters rather than in waste-
waters. One reason that this is in for
a low priority is that it does not seem
to be much of a problem in wastewaters
as a rule.
150
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QUESTION: Mr. Francis M. Mlddleton,
EPA/NERC, Cincinnati, Ohio. While you
have mentioned monitoring and instrumen-
tation in this presentation and in the
previous one, did anyone give any consider-
ation to the level which we are now at in
terms of ability to measure and monitor
the important things? Do we have to have
a $50 million instrumentation program or
are we halfway there? I imagine you didn't
have time to get deeply into that. I think
maybe it's a deficiency in our program
here that there isn't more consideration
of measuring the state of the art. But
did you consider that?
RESPONSE: Mr. Dryden, Sanitation Dis-
trict of L.A. County, Whittier, California.
We did not talk a great deal about monitor-
ing because we felt that was in the domain
of the reliability group and we were in-
structed to try to stay out of their do-
main. Obviously, monitoring and instru-
mentation are extremely important parts
of this. I would say that the kind of
budgets we are proposing would probably
have some money there for efforts of that
type. But we did not try to conceptualize
the monitoring problem.
QUESTION: Mr. Middleton, NERC, U.S. EPA,
Cincinnati, Ohio. Did Mr. Bellanca get
into that?
RESPONSE: Mr. Bellanca, Virginia Water
Control Board, Richmond, Virginia. Not
in that detail.
COMMENT: Moderator Convery, AWTRL, U.S.
EPA, Cincinnati, Ohio. We did have in
both workshop sessions the concept of in-
dicator monitors which was not as a result
of the characterization studies but the
concept of trying to find which breaks
through earlier on carbon.
COMMENT: Mr. Roesler, EPA/NERC, Cin-
cinnati, Ohio. I would also like to add
to John Convery's comment about the indi-
cator parameters. Our philosophy toward
the indicator parameters was that we felt
that many of the conventional parameters
that are used to monitor wastewater streams
or drinking water streams are unsuitable
for automation, such as carbon-chloroform
extracts and BOD5. The time taken to run
these samples is too long. By the time
you get an answer, the water is already in
the distribution system. So we felt that
a program should be developed to determine
new indicator parameters; perhaps some-
thing along the line of E. coli to indicate
bacterial pollution in the streams.
RESPONSE: Mr. Dryden, Sanitation
District of L.A. County, Whittier, Cali-
fornia. I believe there is some feeling
in our group that a sensitive, contin-
uous TOG analyzer may be fairly close at
hand, but we really didn't get into that.
COMMENT: Mr. Roesler, EPA/NERC, Cin-
cinnati, Ohio. You see, the problem with
the TOG is that it is not accepted by all
the states as a reliable indicator of
pollutants coming in or leaving the plant.
COMMENT: Ms. Gorchev, EPA, Washington,
D.C. I like very much the idea of giving
cost estimates, and your total amounts to
about $9 million. I guess that takes
care of Mr. Rosenkranz's budget.
RESPONSE: Mr. Dryden, Sanitation Dis-
trict of L.A. County, Whittier, California.
We did not operate with the constraint
that we were going to have to do the re-
search within existing budgets. I think
if you start with that presumption, we're
through now and we don't have to continue.
The fact is that we are talking about a
program that deserves a research effort
of significant proportions, and we trust
that this workshop will be a step in de-
fining that need in a way which ultimate-
ly will lead to proper funding of a pro-
gram of this type.
COMMENT: Ms. Gorchev, EPA, Washington,
D.C. I was just thinking that for the
other research needs, you people in
treatment have had a headstart anyway. So
for the other workshop estimate, this
might be at least double or triple per
year.
QUESTION: Mr. Schmidt, SCS Engineers,
Long Beach, California. I have wondered
where the existing advance waste treatment
facilities fell into your plans. I see a
lot of similarity between many of your
treatment chains and those at Tahoe,
Orange County, and so forth.
151
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RESPONSE: Mr. Dryden, Sanitation Dis-
trict of L.A. County, Whittier, California.
The question of where you perform a par-
ticular study or train would take into
account where there are existing facilities.
I am sure that an attempt would be made
to utilize existing systems where appli^
cable. I don't think that the trains we
have envisioned are precisely in produc-
tion anywhere at the present time. Com-
ponents of the systems that we are talking
about have been tried, and at least on a
very small scale, there is some knowledge
about almost all of them. But we would
like to see them demonstrated on a large
scale. We would hope that the cost can
be reduced if they can be integrated into
existing advance waste treatment efforts.
Sometimes you have constraints in that
the existing programs are designed to per-
form a particular task right now and they
are not really available for research
evaluation. That type of problem has to
be taken into account. You can't go in
and change the variables on an existing
production-type program in order to pro-
duce our results. If the existing plant
has a different set of objectives that
they have to meet, their objectives are
going to govern what happens. Those situ-
ations, obviously, would need to be in-
vestigated as you decide where and how to
put these chains into test conditions.
QUESTION: Mr. B. Gees J. Zoeteman, WHO
International Reference Centre for Com-
munity Water Supply, The Hague, The Nether-
lands. I think that the available treat-
ment technology is rather limited in its
possibilities in general, and, therefore,
I would like to support your point dealing
with new methods. Are there any specific
ideas within your group of what kind of
new methods could be applied in the future.
RESPONSE: Mr. Dryden, Sanitation Dis-
trict of L.A. County, Whittier, California.
My impression would be that when we say
"new methods," we are thinking about things
people have not thought of yet and, there-
fore, they are not in their minds at the
present time.
QUESTION: Mr. Middleton, NERC, U.S. EPA,
Cincinnati, Ohio. I would like to hear
Fred say a few words about the hope for
catalytic oxidation for that last bit of
pollution we are going to worry about. He's
working in that area.
RESONSE: Mr. Fred Bishop, U.S. EPA,
National Environmental Research Center,
Cincinnati, Ohio. Frank is referring to
a system to be used to remove the last
trace of residual organics. For this one
needs a very potent oxidant which would
not tend to produce residual components
which are incompatible with our biologi-
cal systems. The best hope for this is
probably in the single electron peroxide
pathways or molecular oxygen oxidation
sequences which are called free radical
oxidation. The most potent oxidant
available in this particular area is the
hydroxyl-free radical. That particular
radical will abstract hydrogen from any
carbon-hydrogen bond. It has the poten-
tial, therefore, of totally destroying
organic residuals in the water.
Since the amounts of organic residuals
are relatively low, one can afford to put
in excess amounts of these oxidants and,
thereby, potentially destroy most of the
residual organics. Of course, the pro-
blem of doing it is related to the means
of generating the hydroxyl radical or
the actual hydroxyl species within the
water. One of the ways of doing this is
with ozone. Oz:one, will serve as a con-
ventional oxidant, by itself, but with a
suitable catalyst, such as ultraviolet
light, it will also go the free radical
route and will cause additional destruc-
tion of the residual organic components.
Of course, there are the cost considera-
tions of getting the ozone and the ultra-
violet into the water.
A second approach could involve the use
of hydrogen peroxide with ultraviolet
light or a peroxyl catalyst. Each of
these will generate the free radicals
which will attack the residual organics.
Now whether we can go all the way down or
how far we can go in eliminating residual
organics hasn't really been determined,
but I think the possibility is quite
strong that we will be able to do a very
good job. The kind of residual components
that are left with the oxygenated organics
are relatively high oxygenated organics.
Hopefully these would be considerably less
toxic in the chronic area than the chlori-
nated compounds.
We have an engineering problem of putting
the necessary oxidant into the aqueous
solution. However, this may not be as
tough as it might appear on the surface.
152
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WORKSHOP ON HEALTH EFFECTS OF POTABLE REUSE ASSOCIATED WITH
INORGANIC POLLUTANTS
Chairman: John R. Goldsmith, National Institutes of Health, Cancer Institute
Vice-Chairman: Gunther F. Craun, -Environmental Protection Agency, WRSL
Cincinnati, Ohio
GENERAL PRINCIPLES
Research on this topic is intimately
related to other environmental health
research, and especially to that
relevant to drinking water criteria
for standard setting. This research
is also related to ongoing studies
and to that on categorical diseases
such as cancer, heart disease, and
to geographical gradients in mor-
bidity and mortality.
Given data on occurrence of materials
in water, a balanced use of epidemio-
logical and toxicological research
is necessary. It is reasonable to
assume that in different communities
different constituents will be pre-
sent - hence a responsive system of
research studies will be needed.
A general epidemiological strategy
would include epidemiological work on
water constituents along with other
broad-scale, long term epidemiological
work. A general toxicological stra-
tegy would be based on population -
dose estimates and on indices of mix-
tures tested in model systems such as
cell cultures, and in other more con-
ventional experimental procedures.
Results of such research should con-
tribute to criteria for inorganic
constituents, through open scientific
review and if the data are sufficient,
.the data may be used to set standards.
;The standards may and should reflect
feasibility, cost, and other con-
siderations than health.
Research on Occurrence. Some mate-
rials have optimal levels of inges-
tion or in water supplies, levels
which are either not harmful or may
be beneficial. An objective of the
research program is to classify
occurrence by concentration into
zones which indicate the level of
health concern (or benefit).
DETAILED PROPOSALS FOR STUDIES
1. A. Local Variations In Occurrence
in Communities with Varying
Proportions of Reused Water.
Determine those specific
geographic areas where use of
reclaimed water for potable use
is most imminent. Examine the
waste streams from those, or
selected similar, areas to deter-
mine the presence and concentra-
tion of inorganic (and organic-
metallic) substances which are
not currently included in the
drinking water standards.
There is also a need to com-
pile and/or analyze the influent
and effluent from existing pilot
or actual reuse situations to
determine the occurrence of in-
organic constituents. Samples
should be collected at represen-
tative taps to reflect actual
exposures of water supplied, in-
cluding the effect of distribu-
tion materials. Wastewater
treatment may produce an un-
stable water which could be cor-
rosive to distribution piping.
As new technologies are intro-
duced and used, various products
will find their way into waste-
waters. In light of this,
studies of occurrence of
153
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materials released by new techno-
logy into wastewater should be
part of the national technology
assessment process.
B. Multi-elemental Analysis.
Use of multi-elemental anal-
ytical techniques such as spark
source mass spectrometry, x-ray,
fluorescence and emission and
neutron activation, etc. should
be encouraged to document the
occurrence of inorganics in water
and wastewater for reuse. Re-
search is needed in perfecting
sample preparation techniques,
and in increasing the sensitivity,
accuracy and precision in this
area. Application of these tech-
niques can be used for epidemio-
logic studies and body burden
studies (hair, nails, blood) to
assess the occurrence of inor-
ganic contaminants in the general
population also.
Compounds such as NO- and NO.
and constituents such as asbestos
which cannot be determined with
multi-element techniques should
be determined as appropriate.
C. Characterization of Organometallic
Compounds and Metal Chelates.
Such materials are widely
used in industry and have a high
probability of occurrence and
buildup in wastewaters. Little
is known of their health effects.
Identification of such organ-
ometallic components in waste-
waters is difficult. Existing
analytical techniques are avail-
able in chemical engineering and
industry.
Examples include alkyl and
aromatic amines and dicarboxylic
acid compounds (components hav-
ing available electrons for shar-
ing with electron deficient com-
ponents) .
The inorganic counterparts
generally are the electron der-
ficient cations of metals cap-
able of forming complexes with
electron rich organic components
or chelates. Cations of cadmium,
lead, magnesium, calcium, stron-
tium, barium, nickel, copper,
tin, cobalt, iron, and manganese,
are a few that are possible.
Body Burden-Introduction
Body burden estimates can be thought
of as a first step in a continuum of
effects. The later or more serious
steps occurring with greater expo-
sure are: a) impairment of function
or performance, b) aggravation of
disease and c) causation of new
disease. For many contaminants evi-
dence of causation of disease has
required long exposures, large
numbers of persons, and the passage
of many years. Body burden changes
can be detected much more readily
and much earlier (i.e. with less
exposure) than manifest toxicity.
This has been shown, for example, for
lead and cadmium. Hence a greater
level of health protection is im-
plied by protection against in-
creased body burden than would occur
if one awaited more serious effects.
In some cases, an increase in body
burden, in the absence of other
effects of a substance, indicates
only a biological interaction with
the substance. In other cases, the
body burden increase may signal the
onset of impairment or disease.
A. Use of Autopsy Studies to Deter-
mine Human Body Burden.
Where cities are known to
have differences in water con-
stituents, autopsy, placental
tissue, or surgical specimens
may show that different water
constituents lead to different
concentrations of these same
constituents in target organs.
In addition, such data may make
it possible to relate high
levels of storage to morbidity
and mortality from various
causes. Samples generally used
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as body burden estimates (hair,
blood, etc.) in living popula-
tions should be compared to the
appropriate organ or tissue
(liver, kidney, brain, bone,
etc.) which can only be sampled
in autopsy studies.
B. Population Screening for Esti-
mates of Body Burden.
Populations consuming water
of varying qualities with respect
to certain contaminants can be
sampled to determine whether
these contaminants are taken up
and stored. This would, if ob-
served, indicate some level of
biologic transport or interaction.
When such studies are done, other
sources of these contaminants
must be controlled (e.g.
occupational exposure, smoking,
food, air contamination).
Body burden estimates have
been based on samples of scalp
hair, nails, blood, urine, sub-
cutaneous fat, decidious teeth.
Expired air and ear wax samples
have been used for other purposes
but may be inappropriate for
study of inorganic water con-
taminants.
Such determinations can be
included in epidemiologic studies
and epidemiologic principles
should be applied in their
analysis.
C. Physiological Availability of
Inorganics in Water.
The mere presence of an ele-
ment or compound in water need
not imply that there is any appre-
ciable uptake. For example, the
material may be in an insoluble
form or it may be complexed or
chelated. Little is known about
the role of particulate matter
which may influence the uptake or
bind particulates to other mate-
rials .
Both animal and human studies,
along with improved physical-
chemical characterization, are
needed to determine the uptake
fractions for various forms of
inorganic constituents in water.
These uptake fractions may vary
with age of the subjects or with
the amounts of these or other
materials in the diet.
Better data are needed on
water consumption extremes that
occur because of occupation, age,
climate.
Toxicological Studies
A. Use of In Vitro Methods to Screen
Classes of Concentrated Toxicants
Including Screening for Carcino-
genesis and Mutagenesis.
It is recommended that EPA
make use of a balanced applica-
tion of a wide variety of in
vitro and in vivo systems for the
study of contaminants in water.
This should certainly include
several in vitro systems includ-
ing bacterial and cell culture
systems.
A possible strategy for the
use of these systems would be as:
(1) Primary toxicity screens.
(2) Indicator systems for
determining active frac-
tions in various frac-
tionation schemes and
refractionation of the
active portions.
(3) Systems for the study of
the interactions of chemi-
cals for toxicity includ-
ing mutagenesis and car-
cinogenesis.
Such toxicity testing depends
on concentrating materials in
wastewaters and fractionating
the concentrate according to
generally accepted principles of
physical affinity and biological
or chemical activity.
155
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Data exist on a variety of in
vitro techniques that may be con-
sidered suitable for this purpose.
Animal toxicity testing
should be used to validate such
techniques where appropriate.
B. Animal Models of High Risk Popu-
lations.
Conventional animal toxicity
studies use relatively healthy
normal animals, yet the human
health effects of greatest concern
involve effects on infants (ni-
trates and nitrites) and on those
with cardio-vascular diseases
(sodium, hardness).
In addition, concern about muta-
genesis, teratogenic effects, and
effects on pregnancy outcome
imply needs for study of exposures
during reproduction in animals.
There are no well established
relationships between results on
healthy animals, and those with
impairment. Accordingly study
of selected types of impaired
animal systems is needed if data
are to be obtained which are
relevant to high risk human
groups.
C. Population-Dose Estimation.
The amount of a material in
potable water does not necessarily
relate to the amount ingested,
since a high proportion of the
liquid intake is from food and
beverages. Food and beverage pre-
paration may increase the concen-
tration (by boiling) or decrease
it (by adsorption, say, to tea or
coffee grounds).
It is necessary for each sub-
stance and class of substance to
estimate the population dose
based on usual food, beverage and
water ingestion.
In addition, in locations, or
types of employment, with high
environmental temperatures much
higher intake of fluids is likely
and it is often in just such lo-
cations that potable use of
wastewater will be most attrac-
tive.
D. Behavioral Toxicology.
Behavioral toxicology has
been shown to be a. useful test
system for effects of nitrites
in rats. It has been shown to
be a very sensitive indicator of
effect for certain compounds and
is probably the only way alterna-
tions in cerebral function by
toxic agents can be approached
in animal studies.
Epidemological Studies
The study of the effect of the envi-
ronment upon the health of the popu-
lation, i.e., epidemiology, depends
upon the appropriate measurement of:
1. Various parameters of the environ-
ment, including specifically the
content of the drinking water,
including overt and covert re-
use,
2. various measures of health
effects, including age-sex-race-
specific rates of mortality and
incidence of disease, and
3. the relationship between these
two groups of variables, pro-
perly controlling other relevant
variables such as occupation,
income, nutrition, smoking,
altitude, etc.
In some instances economy of effort
is possible by development of multi-
purpose studies, while in other in-
stances, such as cancer registries,
the development of local organiza-
tions, and of systematic and com-
plete data systems along with persis-
tent effort will be required over a
period of years.
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Collaborative efforts from many
groups can assist in planning and
conducting the needed studies. One
possibility is that a commonly agreed
water assessment strategy might be
developed to insure that kinds and
amounts of pollution and possible
health reactions are measured uni-
formly. A small, interdisciplinary
group with international support
could be convened to develop and de-
sign such a strategy.
Since the W.H.O. International Refer-
ence Center has proposed such a
joint effort, one mechanism for such
a cooperative effort exists.
A. Relation of current-water quality
to incidence and prevalence of
chronic diseases.
Research is needed on the re-
lationships of 1) content of the
drinking water and 2) the age-
sex-race-specific risk of death,
particularly for age groups be-
tween 35 through 74 years, for
all causes as a group as well as
for specific causes in geographic
areas for which data can be read-
ily obtained in relation to
sodium, hardness, TDS and trace
metals. Comparisons of areas
using polluted and clean raw
water intakes should have priori-
ties.
There are convincing statis-
tically significant differences
between geographic areas in the
risk of dying under age 75. If
environmental characteristics of
the lowest-rate areas could be
applied to "higher death risk
rate" areas throughout the U.S.,
there would be an estimated
160,000 fewer deaths per year
under age 75 (or 100,000 under
age 65) .
Present data relating death
rates to components of drinking
water including components re-
sulting from indirect reuse of
wastewaters are confused and un-
certain.
Approach:
1. Obtain information on the
content of the drinking
water, both bulk and trace
substances for metropolitan
areas and cities with avail-
able data with emphasis upon
areas exhibiting a wide range
of death rates.
2. Calculate age-sex-race-
specific death rates, all
causes and cause-specific
(age 35 through 74 especially)
for 3 or 5 years around the
1970 census for the specific
areas for which available
water data exist.
3. Study the degree of associa-
tion or correlation between
point 1 and 2, paying due
attention to the contribution
of other variables. Explore
methods for increasing the
scientific rigor of all
points stated.
B. Collection of Health Data Before
and After Direct Reuse.
Rates of the incidence and
prevalence of chronic disease are
sought for many purposes in re-
lation to the study of the effects
of the environment upon health,
including the reuse of water for
potable purposes, both overt and
covert. Properly designed regis-
tries may be an efficient basic
tool for this purpose.
A city planning overt reuse
of water will require many dif-
ferent types of data accurately
collected and analyzed, to deter-
mine whether reuse has an adverse
effect. Data should include two
or more years before overt reuse
and at least for several years
after, on incidence and preva-
lence of various chronic diseases,
as well as information relevant
to possible acute episodes.
Registries may be either of
persons with a given disease such
as cancer, or of persons with a
157
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given exposure such as to potable
wastewater. They are expensive
and require persistent work by
well-motivated individuals. In
those special situations in which
local people are genuinely and
persistently interested in achiev-
ing goals that can be accomplished
through the use of a registry and
related work, it provides a poten-
tial for producing very valuable
data for many purposes.
A useful population registry
will probably require a minimum
of 7 or 8 years to provide useful
information.
C. Hypertension and Cardiovascular
Disease Associations with Drink-
ing Water.
Associations of cadmium inges-
tion and hypertension have been
reported.
In Great Britain convincing
evidence has shown the association
of hardness with low rates of
cardiovascular disease. The sub-
stances responsible for this
association have not been clearly
determined. Some of the contami-
nants in reclaimed wastewater may
be relevant to this association.
Such studies in other countries
including the U.S. have indicated
the possible relevance of sulfate-
bicarbonate ratios, lead, copper,
magnesium and sodium. Comparison
studies between otherwise compar-
able communities or longitudinal
studies in communities changing
their water supply system can
assist in resolving these ques-
tions .
D. Assessing Contributions of Water
Quality to Variations in Chronic
Disease Rates.
Rates of the incidence of
"serious" chronic disease, age-
sex-race-specific vary from place
to place. Presumably, this is a
reflection of environmental ef-
fects of which water constituents
may be one possible cause.
Areas exhibiting marked dif-
ferences in chronic disease death
rates are found in such locations
as Boulder, Colorado and Russell
County, Alabama or Cache County,
Utah and Silver Bow County,
Montana. These and similar con-
trasting geographical pairs
should be utilized in determin-
ing the possible relationships
between disease incidence and
concentration of water consti-
tuents indigenous to each area,
controlling for other relevant
variables.
Serious diseases may be de-
fined as those which are incapac-
itating and which nearly always
require hospitalization. Such
instances are found in lung
cancer, stroke (exclusive of
transient ischemic attacks) and
acute ischemic heart disease.
Present information suggests
that documentation of incidence
of such diseases may be ade-
quately obtained from hospital
discharge reports and death cer-
tificates when they are checked
against each other to prevent
duplication.
The approach eliminates the
burdensome task, of relying upon
a physician's memory for each
case study which may be very
costly.
Workshop Participants:
Willard R. Chappell, Director, Molybdenum
Project, University of Colorado, Boulder,
Colorado.
Robert T. Christian, University of Cin-
cinnati, Kettering Lab., Cincinnati,
Ohio.
Gunther F. Craun - Vice-Chairman, EPA,
WRSL, Inorganic Studies, Cincinnati,
Ohio.
John R. Goldsmith - Chairman, National
Cancer Institute, NIH, Bethesda,
Maryland.
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Hand Gorchev, EPA, Washington, B.C.
Cheng-Chun Lee, Pharmacology and Toxicology,
Midwest Research Institute, Kansas City,
Missouri.
Miriam Orleans, University of Colorado
Medical School, Denver, Colorado.
Herbert I. Sauer, Community Health & Exten-
sion Environmental Quality, University
of Missouri, Columbia, Missouri.
Rexford D. Singer, University of Minn.,
Minneapolis, Minnesota.
Harold Wolf,.Director, Dallas Water Re-
search Center, Dallas, Texas
DISCUSSION
QUESTION: Mr. McCabe, Criteria Develop-
ment Branch, Water Supply Research Lab.,
EPA, Cincinnati, Ohio. John, in your pro-
posal for studies before and after potable
use of reclaimed water, did you talk
about the possibility of tissue-banking
before you started, so that you keep open
the option to do some body burden studies
as well as your morbidity collection be-
fore and after?
RESPONSE: Mr. Goldsmith, National Cancer
Institute, NIH, Bethesda, Maryland. No,
we didn't. It is a very good point and I
think it is appropriate to add it. I think
that is partly because we isolated the body
burden from the epidemiologic work, which
was a mistake. But we followed the classi-
fication presented in your report, Lee.
So we will try to put it back together
sometime.
COMMENT: Mr. Lee, Washington University
Medical School, St. Louis, Missouri. Dr.
Goldsmith, I would like to make a few
comments about your editorial modifications
to the section on the organometallic and
metal chelates.
The idea here was that there is really
no instrumentation for analyzing any of
these compounds, and any type of work that
is being done by nature will be very te-
dious and difficult. So if you address
yourselves to organometallics, the idea
was to get to know the compounds that are
used throughout the industries as stabili-
zer or extender reinforcement. And if
they make the compound, no doubt they know
the chemistry of it and the structure of
it. What we look for are forms that we
know will be modified; i.e. oxide form,
the halogenated, and the hydroxylated,
and then identify them.
For the more complex forms of the metal
chelates, since they are not as chemically
stable, the first approximation would be
to identify the chemical components that
would be able to form chelates. This
would be the alkyl and aromatic amines,
and any type of electron-rich source
that can form chelate-type lignins with
cations such as those you have listed.
This is only the first approximation.
It would be desirable to include not
only the chemical constitutents, but a few
of the chemical variables and physical
variables that they are exposed to.
QUESTION: Mr. Tardiff, EPA, NERC,
Water Supply Research Laboratory, Cin-
cinnati, Ohio. In your general conclu-
sions, the second one discussed emphasized
the fact that there were differences from
community to community, particularly with
regard to their constituents. Later on
in your text you also talk about differ-
ences in morbidity and mortality, and
other disease parameters. Are you sug-
gesting that we should be performing
epidemiological and/or toxicological
studies on community bases as opposed to
doing generalized studies which allow us
to set national drinking water standards?
RESPONSE: Mr. Goldsmith, National Cancer
Institute, NIH, Bethesda, Maryland. I
think the general interest and emphasis
of the panel was to stress community-based
epidemiological studies under guidelines
that were set up nationally with support
and collaboration from national resources
and with a great deal of interaction with
an international effort in order to make
sure that there was efficiency and valid-
ity of many of the methods used.
The other reason for stressing this was
because it is somewhat easier on a com-
munity basis to develop a multi-purpose
application of the epidemiologic work so
that it isn't necessary that all of it be
supported solely for purposes of water
research.
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QUESTION: Mr. Tardiff, EPA, NERC, Water
Supply Research Laboratory, Cincinnati,
Ohio. I was trying to determine whether
you are going to get data which would
allow you to set community standards or
national standards, and whether national
standards are even warranted?
RESPONSE: Mr. Goldsmith, National Cancer
Institute, NIH, Bethesda, Maryland. I
think what we were concerned about is the
variation between communities and the con-
stituents in the wastewater stream. Of
course, there are also potential variations
in the community in the proportion of sus-
ceptibles and other factors.
I don't see any contradiction between
community epidemiologic studies and their
reflection on, and support of, national
quality standards. I am speaking from
experience in other areas but I know that,
in general, the strong community studies
have had a great influence in national
programs and in national standards. So, I
don't see that the conflict is a substan-
tive one. I can see that it might appear
to be. I think that when experience is
acquired, it will be seen not to be as
serious a matter as it might suggest.
QUESTION: Mr. Ongerth, California
Department of Health, Berkeley, California.
I am not sure I can follow the subtleties
of this interchange between the two of you.
Doesn't a community survey, contrasted
with a control population someplace else,
give you one point on a curve? For a com-
munity that is exposed to constituent JK
you have one point on the curve which
represents the effect on community health
at this level of exposure to constituent
3c. If you have enough communities, you
have a number of points on the curve and
you can extrapolate or project back down
to some information that enables you to
set the standards. This is an engineer's
concept of toxicology and environmental
epidemiology. Am I off the track?
RESPONSE: Mr. Goldsmith, National Cancer
Institute, NIH, Bethesda, Maryland. A
great deal depends on the nature of the
study. Many of the body burden studies
generate a whole curve with one study.
That is, of course, very important. But
in some epidemiologic studies, you get a
number of points as the output because you
can rank the populations by exposure in,
say, seven or eight different groups and
estimate the effects. Then you have seven
or eight points. There are, of course,
epidemiologic studies which only produce
one point. But a great deal depends on
the nature of the study.
COMMENT: Mr. McCabe, Criteria Develop-
ment Branch, Water Supply Research Lab.,
EPA, Cincinnati, Ohio. John, I think in
the report you did allude to the fact
you were concerned that the areas of the
greatest water consumption would be the
areas where this reuse might take place.
So, I think you may have already talked
about a unique community standard and
not a national standard because your con-
sumption is going to differ.
Also, if you are going to do the com-
munity study, you will get some insight
into food consumption that might be dif-
ferent in certain parts of the country
than in others.
RESPONSE: Mr. Goldsmith, National Cancer
Institute, NIH, Bethesda, Maryland. My
personal preference is for the reporting
of national criteria which are clearly
and lucidly interpreted and give guidance
to community standards. But I have no
opposition whatever to national standards.
I think in many cases it is the only way
to go when a given material is hard to
study, and when studies are few.
One of the other approaches to community
variation in exposure is to take into
account the environmental temperature.
This, of course, has been recommended for
standards related to optimal fluoride
ingestion, and it is a worthwhile example
to keep in mind.
COMMENT: Mr. Shuval, Director, Environ-
mental Health Laboratory, Jerusalem, Israel.
I would like to further this point rela-
tive to developing data for a dose-re-
sponse relationship. I think that the
workshop group dealing with the health
effects of organics is going to come up
with a recommendation relative to the
value of international cooperative studies.
I think it holds just as true at this
point that if we are going to get reliable
data on the response to environmental
stress (in this case, water stress, organ-
ics or inorganics), we will need to choose
a number of selected sites where this can
be done. I think that it would be wisest
to draw up a standard protocol for running
160
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such studies, which really requires very
fastidious Control, and then to select
optimal sites with a complete range of
concentration levels. This would mean
using the best sites available in the
world, whether they be New Orleans, Cin-
cinnati, London, Rotterdam, or other cities
throughout the world. I think that the
well-designed dose-response study which
is required to provide answers in the
United States, should use the best avail-
able sites in the world. This would call
for the type of international program
that the World Health Organization Inter-
national Reference Center has suggested.
Their suggested program included a feasi-
bility study to design such a series of
studies followed by actual conduct of the
study.
COMMENT: Mr. Gordon W. Newell, Stanford
Research Institute, Menlo Park, California.
I am concerned about this setting of stan-
dards in terms of health effects. Gentle-
men, we are talking about the effects of
materials and chemicals as toxicants, and
you have to know what is specific about
each one. As Dr. Goldsmith points out,
in some cases you have an environmental
effect which can modify the response and
the tolerance that people have. You get
into some areas where you have differences
of pH in relation to a particular chemical
which will affect adsorption or retention.
So I don't think we can talk about stan-
dards per se. We are talking about defin-
ing the effects in the body associated
with these things. We should be very
careful in what we propose in terms of
looking at the toxicants in relation to
the amount of contaminants that are going
to be in the water. We have got to under-
stand at what level man can tolerate these
things before we worry at all about the
s tandards.
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WORKSHOP ON HEALTH EFFECTS OF POTABLE REUSE ASSOCIATED WITH
VIRUSES AND OTHER BIOLOGICAL POLLUTANTS
Chairman: Edwin H. Lennette, California Department of Health
Vice-chairman: Gerald Berg, Methods Development & Quality Assurance Laboratory,
Environmental Protection Agency, NERC, Cincinnati, Ohio
PRIORITY 1 - ADSORPTION OF VIRUSES TO
SOLIDS (High Priority)
Rationale
The disinfection process is a major
means by which viruses are rendered non-
infective in any water treatment system.
In order to achieve disinfection, the
inactivating agent must reach the virus.
When viruses are imbedded in fecal or
other solids, or physically protected by
adsorption to clays or hydrated metal
oxides, the chlorine or ozone or other
disinfectant species will not reach the
virus or may diffuse so slowly through the
debris surrounding the virus that disin-
fection will not take place in the reten-
tion times available. This is a very real
problem with renovated waters inasmuch as
fecal material which escapes the earlier
treatment processes will reach the disin-
fection process.
Methods are needed for the determina-
tion of the extent to which protection is
afforded to viruses by adsorption to, or
entrapment in, solids at low turbidity
levels (0-1 JTU).
Research
The approach to this problem should
consist of a two-stage program concerned
with first, the development of methods for
the detection of viruses on or in solids
and the role that each of the various
types of solids might play, and second,
the development of methods by which the
adsorbed viruses may be exposed to the
disinfectant and thus inactivated.
The types of solids which should be
examined include fecal matter, clays,
hydrated metal oxides, carbonate and
phosphate precipitates, activated carbon,
activated sludge, and organic matter.
This phase of the research program might
require approximately three years.
Investigation of the methods by
which the disinfection process might be
improved should include at least the
effect of increased contact time and dis-
infectant dosage, power input to provide
disintegration of the solids, and dis-
infection by the methods which do not
depend upon a diffusing molecule, e.g.,
ionizing radiation.
This latter study may require three
years but could, in its latter stages,
overlap with the study mentioned above.
Length of Study; Five to six years.
PRIORITY 2 - METHODS FOR DETECTION OF
HEPATITIS A AND OTHER VIRUSES
IN WATER (High Priority)
Rationale
Hepatitis A virus is the major en-
teric virus involved in water-borne dis-
ease outbreaks, and the development of
methods for its detection and identifica-
tion are of the highest importance. The
development of methods for detecting and
identifying other viruses that occur in
water and can infect man are also im-
portant.
Research
Methods are needed for the detection,
isolation and assay of hepatitis A (infec-
tious hepatitis) virus. Although current
research indicates that this agent can be
propagated in marmosets, in vitro methods
are necessary if meaningful studies on
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the occurrence, persistence, and fate of
the virus in wastewater as well as in
various treatment processes is to be
assessed.
Methods are also needed for the detec-
tion, isolation, and assay of other viruses
excreted from the human enteric tract, and
which are of public health importance in
renovated waters. The viruses of major
public health significance in renovated
waters are obviously those which are cap-
able of infecting or colonizing the intes-
tinal tract, and which are excreted in
large quantities. These agents belong to
the following major viral groups:
Hepatitis A viruses (ES)
Hepatitis B virus
Enteroviruses
Polioviruses
Echoviruses
Coxsackieviruses, Group A
Coxsackieviruses, Group B
Adenovirus es
Reoviruses
Other viruses that may be excreted by
man in the feces, urine, saliva, and in
respiratory, genito-urinary and ocular
secretions may also be of potential public
health significance in renovated waters,
but they have not been isolated from do-
mestic sewage or treated sewage effluent,
and thus are of unknown significance.
Length of Study: Four years.
PRIORITY 3 - INACTIVATION OF VIRUSES IN
RECLAIMED WATERS (High
Priority)
Rationale
At the present time there is only very
limited information on the mechanism(s) of
inactivation of viruses by disinfection
and adsorption. The necessity for obtain-
ing exact information on this problem is
based on the following considerations:
1. Our present knowledge of the
mechanisms of viral inactivation
is based primarily on the use of
polioviruses as a model. However,
with respect to reclaimed water,
there are more than 100 other
viruses which are of potential
concern. Admittedly, it seems
unlikely at the present time that
all of these viruses will be
studied in the near future from
the standpoint of inactivation.
However, if the exact mechanism
of inactivation were known for
some of the more typical or more
frequently occurring viruses,
then it might be possible to
predict the approximate rates
of inactivation of all, or per-
haps many, of the other viruses.
2. Knowledge of the mechanisms of
viral inactivation could quite
conceivably lead to modifications
of existing processes from the
standpoint of increasing their
efficienty in the inactivation
process.
3. The fate of viruses in sludges
may become predictable when ad-
sorption mechanisms are better
understood. The isolation and
enumeration of viral particles
in sludges is very difficult,
but if the mechanism of the ad-
sorption process were understood,
present methods of viral quanti-
tation could be evaluated and
their usefulness enhanced.
Research
The research program to develop the
mechanisms mentioned might be conducted
roughly in the following order.
1. Methods and mechanisms of disin-
fection of viruses by chlorine
and ozone.
2. Nature of the fundamental chemical
reactions between viruses and
disinfecting chemicals. There
is need to develop the necessary
methods for determining these
reactions.
3. Determination of the factors
which affect process control and
which, when optimized, will
assure an essentially microbial
pathogen-free water. Such fac-
tors must be evaluated in a full-
scale wastewater treatment facil-
ity which has been designed and
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operated for the purpose of pro-
ducing a pathogen-free water.
Factors that should be studied
include turbidity, pH, disinfec-
tant and disinfectant concentra-
tion required, interfering nitro-
gen species, and methods for
total control of the organics of
the water prior to disinfection.
4. Studies are also needed on the
interactions between viruses,
disinfectants, and constituents
in the water which interfere
with the disinfection process.
5. The significance of bacteria
which contain the R+ factor.
6. Adsorption processes, e.g., cell
particles, hydrated metal oxides,
activated sludge, activated
carbon, etc. Length of Study;
Five years.
PRIORITY 4 - RAPID MICROBIAL TEST METHODS
(High Priority)
Rationale
There is an unquestioned need for
the development of a rapid and, con-
comitantly, relatively simple test method
that would indicate the presence of
viruses and other pathogenic organisms
in renovated waters. The availability
of such test systems are highly important
because back-up systems are required to
provide multiple levels of safeguards for
water quality. Simple, direct biological
tests are necessary in addition to, and
as a control on, the other operating con-
trol systems already in use, i.e., the
physical and chemical tests and controls.
Length of Study: Three to five years.
PRIORITY 5 - SENSITIVITY OF CELL CULTURE
SYSTEMS FOR DETECTION OF
VIRUSES: A COMPARATIVE
METHODOLOGY STUDY (High
Priority)
Rationale
There is a need for a comparative
methods study and evaluation of various
cell culture systems with respect to
their ability to detect viruses which
might potentially be present in reclaimed
waters. The best system(s) should be
standardized so that a uniform method
would become available to all workers,
and would also permit a comparison of
laboratory findings between laboratories.
Recommended Research
In order of preference, the cell
systems to be studied are:
1. Primary human embryonic kidney
(HER)
2. Primary monkey kidney (MK)
3. Selected stable cell lines
At present the plating efficiencies
of a given virus in the hands of dif-
ferent investigators or laboratories
which use the same cell lines (but from
different animals or sources) give
variable results with respect to recovery
of viruses.
Research should be supported to
provide standarization of cell systems
that would afford a reproducible method
for recovering a test seed of virus and
for assaying infectivity titers.
It is suggested that the following
aspects be studied:
1. Relative sensitivity of the test
lines to the viruses under study.
2. Methods of obtaining more vig-
orous cell monolayers.
3. Age of the cell in relation to
susceptibility to viruses.
4. Optimal formulas for culture
fluids and for agar overlays
for prolonged maintenance of
the cells.
5. The influence of the volume of
viral inoculum on viral titers.
6. "Enhancers" to incorporate in
overlays in order to obtain
maximum sensitivity.
7. Relative sensitivity for the
detection of viruses under agar
overlays and under liquid medium.
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PRIORITY 6 - INTERACTIONS BETWEEN
MICROBIAL PATHOGENS AND
SOILS (High Priority)
Rationale
Information is required on the occur-
rence, survival and fate of viral and
bacterial pathogens in all types of
treatment plant sludges and on the inter-
action between pathogens in the sludges
and soils of varying composition.
Studies on this subject are important
because it has been demonstrated that
most of the viruses entering a wastewater
treatment plant terminate in the sludges,
and it has been documented that these
viruses are released and moved through
some soils.
Research
1. Methods should be developed for
the detection and quantitation
of viruses and other microbial
pathogens in sludges.
2. Studies should be undertaken on
the ability of sludge and soil
to form a complex and to release
viruses under varying conditions.
3. The capacity of soils of various
composition to hold viruses and
the conditions for promoting
viral adsorption and prevention
of their elution needs study.
4. Determination is required of
the time necessary for self- ,
purification of soil-receiving
sites and the frequency with
which safe sludge-loading can be
conducted.
5. Clues are needed on the effect
of operating conditions of a land
treatment system on the survival
and fate of viruses and other
microbial pathogens in soil.
6. Methods should be developed for
the disinfection of viruses and
other microbial pathogens in
sludges. Length of Study: Five
years.
PRIORITY 7 - REMOVAL OF PATHOGENS BY
pH AND COAGULATION (High
Priority)
Rationale
There is a need to prepare from the
existing literature a state of the art
document concerned with the removal and
inactivation of microbial pathogens by
pH extremes and by chemical coagulation
processes. Such information is necessary
for a rational approach to the develop-
ment and standardization of optimum
treatment conditions for the removal
and inactivation of microbial pathogens.
Length of Study: Nine to twelve months.
(In large part because of low cost
involved.) (This project may already
be under way.)
PRIORITY 8 - MINIMAL INFECTIOUS DOSES
OF VIRUS FOR MAN (Medium
Priority)
Rationale
At the present time there is no
definitive, unequivocal information as
to the minimal infectious dose of virus
infectious for man by the oral route.
Such information is important as it
would provide the basis for establishing
viral standards for renovated waters,
both with respect to the potential hazard
and determination of the extent to which
treatment is required for the various
end uses of renovated waters.
Research Need
Information on the minimal amount
of virus that will produce infection
and/or disease in man by the oral route
is almost non-existent or, at best,
extremely limited, e.g., the work of
Katz and Plotkin, using attenuated polio-
virus. Considerable additional data
beyond this are needed, and a research
program employing human volunteers should
yield the necessary information with
respect to the minimal viral dose that
would result in. disease. The latter is
a much more difficult factor to assess
for a variety of reasqns. One approach
with respect to both infection and
disease would be to determine the virus
concentrations present in water during
165
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outbreaks of viral disease in the
populations at risk. Length of Study;
Five years.
PRIORITY 9 - TOXINS AND PYROGENS IN
RECLAIMED WASTEWATER (Medium
Priority)
Rationale
It is well known and recognized that
during the processing of water which
requires contact with such solids as
activated carbon, microbes accumulate
and consideration should be given to the
release of toxins and pyrogens from such
microbial agents.
Research
Information is highly desirable on
the extent to which bacteria which
colonize activated carbon and other
solid contact systems release toxic and
pyrogenic materials. A study should be
undertaken to identify the toxins and
pyrogens which may be released and their
possible deleterious effects on the
health of the population utilizing waters
into which such microbial breakdown
products are released. Length of Study;
Two years.
PRIORITY 10 - SURVEILLANCE FOR VIRUSES
IN EFFLUENTS FROM WATER
RECLAMATION PLANTS (Medium
Priority)
Rationale
At the present there is little, if
any, information on what viruses may be
present in effluents from existing pilot
and full-scale wastewater reclamation
plants.
Research
There is a need to conduct in-depth
surveillance and monitoring for the
presence of viruses, and their concen~
tration, in effluents from existing,
pilot and full-scale wastewater recla-
mation plants which employ treatment
trains that are likely to be used in
future reclamation plants aimed at
production of potable water.
It is only by having information
available on the concentration of
viruses (if any) present in reclaimed
water that we can begin to consider
rationally the public health significance
of viruses in such waters. Length of
Study: Three years.
PRIORITY 11 - AIRBORNE CONTAMINATION
FROM WASTEWATER RENOVATION
PLANTS (Low Priority)
Rationale
The potential public health hazard
of airborne dissemination of pathogenic
bacteria and viruses needs study because
of the general lack of information on
this subject, and because of the adverse
public reaction to plant-siting engen-
dered by misapprehensions on the possible
hazards.
Research
Studies and research are needed on
the following aspects:
1. Development and application of
methods for the sampling, con-
centration, and detection of
airborne pathogenic microorga-
nisms.
2. Information on the factors that
favor or adversely affect
survival and dissemination of
pathogenic microbes in the
airborne state.
3. Development of methods for
controlling the generation of
aerosols and the aerial trans-
port of pathogenic micro-
organisms .
4. The public health significance
of airborne pathogens from
treatment plants as determined
by epidemiologic and other
studies on the role of such
airborne pathogens. Length of
Study; Three years.
Workshop Participants:
Gerald Berg- Vice-chairman, Methods
Development & Quality Assurance Re-
search Laboratory, NERC-EPA, Cincinnati,
Ohio.
166
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John T. Cookson - University of Maryland,
Civil Engineering, College Park,
Maryland.
Stuart G. Dunlop - University of Colorado
Medical Cmter, Denver, Colorado.
Beatrice England - San Diego County
Health Department, San Diego,
California.
Edwin H. Lennette - Chairman, State of
California, Biomedical Laboratories,
Berkeley, California.
Leland J. McCabe - EPA, Criteria Develop-
ment Branch, Water Supply Research
Laboratory, Cincinnati, Ohio.
E. M. Nuperi - N.I.W.R. C.S.I.R.,
Pretoria, South Africa.
Mark D. Sobsey - University of North
Carolina, Chapel Hill, North Carolina.
Otis J. Sproul - University of Maine,
Orono, Maine.
Craig Wallis - Baylor College of
Medicine, Houston, Texas.
Comments on "Municipal Wastewater Reuse
Proposed Strategy Document"
Otis J. Sproul
University of Maine
Orono, Maine 04473
The research needs for "Health
Effects of Potable Reuse Associated with
Virus and Other Biological Pollutants"
will not be met by the program proposed
in "Municipal Wastewater Reuse Proposed
Strategy Document". The research pro-
gram in the biological agent area would
develop background data for various
wastewater treatment trains. These data
cannot be obtained from studies in large
scale treatment facilities such as those
normally funded in the AWTR program. To
attempt to derive requisite data from
studies in these facilities will not be
cost effective. In most cases the
information will be obtained from basic
research studies.
These research needs will be met by
a basic research program. The data from
these studies will interface with the
AWTR program to modify the design,
operation and evaluation of treatment
systems.
DISCUSSION
COMMENT: Mr. Parker, Brown & Caldwell,
Walnut Creek, California. There are
two items in your report which to me,
seemed to be out of place in this con-
text, that of municipal potable reuse
of reclaimed water. Very high priority
is given to determining the fate of
viruses in sludge when applied to land.
My feeling is that this is a general
phenomenon and associated with all water
pollution control projects and not
directly related to the quality of the
product of the potable reuse water.
And I could not, in the context of water
reuse, give this a high rating, although
in the context of water pollution con-
trol and sludge disposal, I could. The
point should be made that one alternative
might be land disposal of sludges from
the advance waste treatment plants that
might produce reclaimed water, but
that is only one of many possible alter-
natives .
Another point I would like to make
before sitting down is in regard to one
of these areas that is related to all
sewage treatment plant operations, and
that is the public health significance
of airborne microbial contamination.
This one, however, is given a low rating
so I can't get excited about it, but it
also is one that, in the overall context
of water pollution control, is important.
However, perhaps as far as diverting
funds from potable water reuse to that
area, I couldn't give it a priority.
But I see that you haven't given it a
high priority.
COMMENT: Mr. Lennette, State of
California, Biomedical Laboratories,
Berkeley, California. I see Dr. Berg
can hardly wait to answer you.
RESPONSE: Mr. Berg, Methods Develop-
ment & Quality Assurance Research Lab-
oratory, NERC-EPA, Cincinnati, Ohio.
I just want to be available to answer
questions along with Dr. Lennette and
that is the only reason I stood up.
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But since I have been pointed to,
let me simply say that I think you are
absolutely correct. It is just a ques-
tion of where you draw the line. If the
virus in sludge is important in the
renovation process, it's because you are
dealing with the total process. If you
want to say it is important also, and
in a primary sense, in ordinary waste-
water treatment, that's true. There's
nothing untrue about that.
As far as the low priority given to
the very last one, I have a suspicion
that it was given a low priority by
different people for different reasons.
In my own case, it was given that pri-
marily because I knew that the Army was
already involved in extensive studies
of that sort, not because I thought it
was unimportant.
COMMENT: Mr. Cookson, University of
Maryland, College Park, Maryland. With
regard to the high priority on virus
retention and movement in soils, I think
indeed this does not impact directly with
regard to direct potable water reuse.
I think what we are trying to emphasize
is that this is really something of
importance right now, not only with re-
gard to direct reuse, but because it has
such significance in indirect seed
spreading and also in the application
in land treatment.
There is the possibility that
aerosols may create a problem by im-
pacting on direct water reuse. We are
finding in some of our high quality
treatment facilities, where we have to
meet very, very stringent coliform
standards on the effluent, that if we
are not careful we get immediate recon-
tamination from the air with coliforms
after a post-aeration process or some-
thing of this nature. So, it may be
important how you locate your final
reservoir in relation to the treatment
plant.
COMMENT: Mr. Sobsey, University of
North Carolina, It occurred to me
after yesterday afternoon's session
that there were probably a number of
research needs that we simply never got
around to addressing. In fact, I thought
one of them was so important—at least,
I, personally, thought it was so important
that I ought to mention it now.
I feel that there is a very strong
need to conduct in-depth surveillance
and monitoring studies for enteric
viruses in effluents from existing
pilot and full-scale wastewater reclama-
tion plans employing treatment trains
that are likely to be used in the future
for potable water reclamation plants.
This is needed in order to determine how
much virus, if any, is present in such
effluents. It is only by knowing how
much or, perhaps, how little virus is
present in such reclaimed waters that we
can begin to rationally consider the
public health significance of viruses
in such waters. So, I think monitoring
and surveillance are some things that
we need to do right away, using the best
available methodology that we have at
hand.
RESPONSE: Moderator Robeck, Water
Supply Research Laboratory, Cincinnati,
Ohio. I believe that Frank Dryden and
the rest of the other group on wastewater
reuse would say that that kind of char-
acterization was meant to be involved in
the statement that he made about char-
acterization on unit processes. We would
agree with you one hundred percent.
COMMENT: Mr. Lennette, State of
California, Biomedical Laboratories,
Berkeley, California. Might I ask Dr.
Sobsey to formulate a statement that
we can incorporate into our document?
RESPONSE: Moderator Robeck, Water
Supply Research Laboratory, Cincinnati,
Ohio. We are perfectly willing to have
him do that, but I reiterate it would
be redundant to what is included in the
proceedings so far..
RESPONSE: Mr. Cookson, University of
Maryland, College Park, Maryland. In
going over this with the committee, it
was my impression that we had included
what Mark just referred to. Perhaps it
did not come out explicitly in the paper,
but this was really under the disinfec-
tion heading as follows:
"Demonstration of factors that effect
process control which., when met, will
assure an essentially virus- and
pathogen-free water. Such factors must
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be evaluated on full-scale wastewater
treatment facilities designed and
operated for the purpose of producing
virus- and pathogen-free waters."
To do this, you really have to go
through an elaborate monitoring process
with regard to parameters. I think it
is in here. Maybe it needs to be
emphasized.
RESPONSE: Mr. Lennette, State of
California, Biomedical Laboratories,
Berkeley, California. This was the
basis for my request to " Sobsey. I
want the record to show that we have
considered it. This was not an error of
omission.
RESPONSE: Mr. Parker, Brown & Caldwell,
Walnut Creek, California. I think we
have hit it more than once and I think
we are beating it to death. Under
research needs, in the treatment for
potable reuse viruses are listed as a
high priority item, and the following
general statement is made: "All pollu-
tant characteristics and the capability
of the individual processes to remove
them will help establish intelligent
source control parameters as well as
potentially lead to process improvement
and new process development."
This is just one of the items that we
want to see monitored through the
potential treatment trains. Whether it
is done in existing pilot plants or new
ones really will depend on funding and
the people involved in the program. I
don't think that we need to enter into
that. I think that we have covered that
area very well.
COMMENT: Mr. Goldsmith, National Cancer
Institute, NIH, Bethesda, Maryland. I
may have misunderstood, or I may be
naive, but it seems to me that if one
is concerned about the viruses in waste-
waters which are ultimately processed
and used for human consumption, one would
like to have long term monitoring of the
harboring of virus disease among employees
of wastewater treatment plants. This is
necessary because the infectivity, and
the trace of infective agents and strains,
may indeed appear earlier among people
who have an occupational exposure than
among the people who are the clients or
customers.
I think that you are going to hear
much more frequently in other forums the
premise that when you are talking
about making a new product available
to the consumer that the detailed occu-
pational experience of the people who
handle and use that product is going to
be thought of as relevant. I believe
that this epidemiologic monitoring
system is necessary and that we have the
tools to undertake it.
RESPONSE: Moderator Robeck, Water
Supply Research Laboratory, Cincinnati,
Ohio. It certainly is part of our pro-
gram and we need to expand that.
COMMENT: Mr. Dryden, Sanitation
District of Los Angeles County, Whittier,
California. I would like to point out
that there is some virus monitoring cur-
rently going on. In particular, we have
embarked upon evaluating some specific
trains for virus removal in Pomona,
California. The State of California
and the EPA are cooperating with us at
this site. There are some reasons to
look at virus removal for water reuses
other than potable reuse, and a lot of
these reuse applications are going to
be developed.
I would also add that the character-
ization studies called for in our par-
ticular treatment group, however, were
related to complete treatment chains
which were deemed to be relevant to a
potable reuse scheme. We feel that this,
too, is going to have'to be done when
those trains are put together. But there
is work going on now on monitoring of
viruses and it must continue.
COMMENT: Mr. Shuval, Hebrew University,
Jerusalem, Israel. I would like to
relate to this problem of issues that
are put into the recommendations of this
workshop which really are universal in
nature and do not refer directly or
specifically to wastewater reuse either
directly or indirectly.
I think many of the proposals, includ-
ing the ones on epidemiological studies
among workers and viruses in sludge, are
subjects that have to be dealt with in
any water pollution control program and
they should not be included in this
report as a special burden for wastewater
reuse applications. I think that
169
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someplace in the preface of the study
or in each section (and I don't think
you should cross them out at this stage),
some identification should be made of
those points which are obviously going
to be covered by other programs and
should not be considered part of the
multimillion-dollar package which is a
prerequisite to get approval for waste-
water reuse.
RESPONSE: Moderator Robeck, Water
Supply Research Laboratory, Cincinnati,
Ohio. That's a good point and I think
we will take that into consideration.
COMMENT: Mr. Shuval, Hebrew University,
Jerusalem, Israel. I think the report
should be as specific as possible. What
are the specific additional research
missions required to further this speci-
fic program which are not being carried
out?
RESPONSE: Moderator Robeck, Water
Supply Research Laboratory, Cincinnati,
Ohio. Oddly enough, we have an adminis-
trative problem along that same line.
So, we are very sensitive to that. We
have two Bills which both talk about
reuse. We want to make sure that each
one is applied to both pollution control
and the health aspects of drinking water.
COMMENT: Mr. Shuval, Hebrew University,
Jerusalem, Israel. I would like to make
one small comment on the question of
rapid monitoring methods for viruses. I
neglected to mention in my talk that I
think there is some hope in this direc-
tion. Dr. Alcott Nelson of our staff
of the Hebrew University has made con-
siderable progress on a fluorescent
antibody technique for detecting entero-
viruses or polio viruses. A "Yes"-"No"
qualitative answer can be' obtained within
nine hours and a quantitative answer
within twenty-four hours. We think,
with refinement, this can be improved.
So we feel that the methodology for
achieving this is on the horizon.
RESPONSE: Mr. Lennette, State of
California, Biomedical Laboratories,
Berkeley, California. We are striving
for two hours.
RESPONSE: Mr. Shuval, Hebrew University,
Jerusalem, Israel. I realize that. And
I think there may be hope for bringing
it down to five or six hours. I think
you need one viral replication process
to be able to identify something in the
cells, and that's about four or five
hours.
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WORKSHOP ON HEALTH EFFECTS OF POTABLE REUSE ASSOCIATED
WITH ORGANIC POLLUTANTS
Chairman: Hans Falk, National Institute of Environmental Health Science
Vice-chairman:. Robert G. Tardiff, Environmental .Protection Agency, NERC, Cincinnati
Many existing water supplies contain
detectable quantities of organic com-
pounds. These organic compounds in water
may represent a possible health hazard
if they are carried through into potable
water supplies. The sources of organic
pollutants in water are diverse and
include municipal wastewater, airborne
wastes, industrial and agricultural
wastes, and other products of commerce.
For certain pollutants, studies should
be undertaken to evaluate the relative
hazard of these compounds from water in
comparison with other sources.
1. Development of a Viable and Visible
Program to Assess the Potability of
Reused Water with a Program Manager
and Coordinator.
Owing to the diversified problems
involved in evaluating the health effects
of potable reuse associated with organic
pollutants, to include toxicity, hazard,
analytical, and problem definition, it
is recommended that a program or project
manager or coordinator be established at
EPA headquarters. The appointed
individual should be charged to prepare
a critical path or similar analysis and
define time and dollar needs and con-
straints.
2. Determine the Definition of "Potable"
Scientifically and Operationally.
The information required to assess
potability of water generated directly
from sewage is- included in the information
required to assess the potability of water
derived from polluted water sources.
There is a requirement for a
scientific definition of what constitutes
"potable quality". When this has been
accomplished, the development of
requirements for toxicity, hazard, and
analytical chemistry research will be
clarified. Safety factor development
will be a politico-economic decision
based upon acceptable risk. There is
a need for the development of screening
methods and the application of existing
methods which are reliable, inexpensive,
and rapid. Short-term (hazard analysis)
should be applied to "grab", "natural"
samples. Long-term studies should not
be applied to these types of samples
without developing a means of character-
izing natural samples. There is a need
for such characterization. This charac-
terization should not be confused with
complete chemical analyses. Long-term
studies should be designed so that the
results are applicable to a series of
problems and, therefore, should best be
performed on well defined samples.
Cost/benefit should be a consideration in
the development of long-term studies.
As objectionable organoleptic
properties of reclaimed water will be
prohibitive for its use and because the
human nose acts as a potential warning
system for the presence of organics in
the water because many organic pollutants
can be smelled before their concentrations
in the water become acutely toxic for
human beings, the reclaimed water as well
as individual pollutants should be
screened for organoleptic properties.
More threshold odor (taste) concentra-
tion data for organics should be obtained
and criteria for restriction of their
discharge in the sewage system should be
developed.
171
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3. Development of Sensitive Analytical
Methodology for Organics in Water
The EPA must support research pro-
grams designed to identify specific
organic water pollutants, some of which
may be hazardous to health. Techniques
of isolation, concentration, identifica-
tion, and quantitation of organics
should be improved. Techniques must be
developed that allow quantitative
recovery of compounds without introduc-
tion of artifacts. More work needs to
be done on the identification of non-
volatile, higher molecular weight
compounds. Research in analytical
methodology for organics in water
should be coordinated with ongoing work
in program areas of sewage, industrial
wastes, and drinking water analysis.
4. The Investigation of the Toxicity
of the Byproducts of Various Types
of Disinfection (e.g., chlorination,
ozonation, UV light, etc.)
The effects of deterioration of
water for biological safety has brought
with it the creation of many new and
potentially toxic chemicals. Attention
must be paid to the reaction products
which may be just as toxic or even more
so than the products of deterioration.
The instability of some of the products
may be of some help, but the residual
compounds, epoxides, aldehydes and acids
may need careful assessment.
Water samples must be analyzed for
chemical composition before and after
the chlorination treatment step, because
certain organic components, like the
phenols will give rise to chlorinated
phenols with much greater toxicity.
5. Development and Application of In
Vitro Microbiological Assays for
the Screening of Organic Mixtures
in Reused Water
The recent development of in vitro
bacterial systems which serve as sensi-
tive indicators of a candidate compound's
carcinogenic/mutagenic potential should
be given serious consideration as a
screening tool early in the hazard
evaluation of a compound or water
concentrate-residue. Since various test
systems are being studied intensively,
and others are evolving, the EPA should
remain alert to new developments in
order to apply the most useful and
reliable methods. The introduction of
hepatic microsoma fractions of rodents
or humans helps to allow for metabolism
of the compound as would occur in
mammalian species.
Besides these tests for muta-
genicity, which also serve as alerting
systems for carcinogenicity testing,
other in vitro test systems assess
cytotoxicity, chromosomal abnormalities
and toxic effects to hepatic cells in
culture, to name only a few in vitro
tests involving mammalian cells.
6. Toxicity Testing of Water Samples
of Fractions of Concentrates
At some stage, there will be a need
to carry out short-term toxicological
studies on actual wastewater effluents
(and concentrates of them) produced by
advanced waste treatment facilities
designed to produce water for potable
use. A pre-requisite for carrying out
such studies is the development of
appropriate techniques for concentrating
refractory organics present in the
waste stream which would, to the extent
feasible, maintain the integrity of the
chemical components, avoid change of
the relative concentrations, and do not
lead to the loss of essential fractions.
A standard protocol for such tests
should be prepared to assure the relia-
bility and comparability of such studies.
The significance of the results
from tests using mixtures (.i.e., con-
centrates) is to predict relative
toxicity, prioritize the in-depth
analysis of samples and systems, and
suggest leads of target-organ toxicity.
Only chemicals identified from highly
toxic fractions and suspected of being
chronically toxic would be subjected to
longer-term and highly specialized
toxicologic testing including the in-
vestigation of their synergistic poten-
tial.
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Long-term feeding studies with
animals may be necessary in the overall
evaluation of the potential hazards of
renovated wastewaters. Such investiga-
tions must use discrete entities which
have been identified in the water systems
of interest. The use of water concen-
trates for this type of study would have
only limited value in relation to the
broad problem. We know that natural
materials vary in composition and amount
over time. Thus a concentrate would be
representative of the water supply only
for the'time when the sample was collected.
Also if adverse effects are observed, the
causative agent(s) could not be determined.
In addition, the volume of a representa-
tive water sample required for an animal
study of any significance would require
massive volumes of water—not taking into
account the losses of volatile components
during concentration.
7. The Metabolism of the Organics in the
Reused Water Should Be Studied in
Order to Determine the Best Possible
Models for Toxicity Testing
In attempting to identify the hazards
of compounds in potential drinking waters,
the metabolism in mammalian systems of
suspect compounds should be studied.
Utilization of short-term in vitro pro-
cedures 5 such as use of • animal or human
liver tissue, may provide important
guidelines in the early screening evalua-
tion of compounds of interest.
8. Assessment of Interaction of Pollutants
Of particular importance are syner-
gistic effects of, for instance, specific
chlorinated hydrocarbons with alcohols
and their oxidation products (aldehydes
and ketones) in enhancing this toxicity.
Synergism is also at play when enzyme
induction may enhance the toxicity of
compounds as CC1, . Synergism has also
been demonstrated for odor enhancement
making such contaminated water undesirable.
9- Development of Rapid and Reliable
Methods for the Monitoring of AWT
Effluent and Their Correlation with
Toxicity
Development of gross chemical of
biological methods which give good
correlation with presence of compounds
of health significance are needed which
can be used for routine monitoring of
drinking water supplies to give reason-
able assurance that organics in the
water do not constitute a hazard to
health.
Organic materials enter water sup-
plies from municipal, agricultural, and
industrial wastes, and from natural
sources. Others are formed during water
or wastewater 'treatment. Some portion
of these organics are potentially
hazardous to public health and may reach
the consumer even after treatment.
Relatively simple and rapid analytical
procedures are required for routine use
to detect when the concentration of
organises reaches levels which are of
questionable safety for human consumption
and thus require more critical analysis
and consideration. Analyses such as COD,
TOC, CCE, VOA, pH, mutagenic microbial
assay, and other potential gross analyses
should be compared with measured concen-
trations of compounds found in water
and known or determined to be potentially
hazardous so that safe levels, based on
the gross techniques,^can be established.
10. Monitoririg of Renovated Wastewaters
and Water Supplies Is Needed to
Determine'What Organic Compounds Are
Present, Their Concentrations, and
Their Variation with Time.
In order to evaluate the potential
health hazards of reclaimed waters for
potable reuse, there is a primary need
to establish the kinds of organics which
are present and their'concentrations.
Such background information will aid in
the formulation of 'tokicological and
other health hazard assessment plans for
organics in drinking water. In addition,
it will be most useful in comparing
characteristics of organics in reclaimed
wastewaters with present drinking water
supplies. This information will also be
most useful in evaluating the need for
and value of various unit processes which
may be used for wastewater renovation.
17.3
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11. Thought Should Be Given to Epidemic-
logic Studies, Where Applicable,
on the Correlation of Human Disease
and Exposure to Organic Compounds
that Occur in Drinking Water and
Other Media
It is recommended that EPA consider
participation in the WHO International
Reference Center on Community Water Sup-
ply's proposed study to determine the
feasibility of carrying out retrospective
and prospective epidemiologic surveys on
population groups exposed to heavily
polluted surface waters (indirect or
covert wastewater reuse). The aim is to
determine whether there are any detri-
mental health effects resulting from such
long-term exposure. Such studies might
include testing of the body fluids and
tissues for the accumulation of compounds
of potential toxicologic importance.
Consideration should be given to carrying
out such carefully designed studies, in a
number of countries on an international
cooperative basis.
An assessment of body stores of
some of the organic components of reused
water in human tissue should be carried
out. This will deal mainly with stable,
lipid soluble compounds which will reach
man also through the food chain and by
other means (medicines for instance).
CHC1,, CC1,, trichloroethylene and per-
chloroethylene have already been detected
in samples of adipose and other tissue of
humans. This information is of importance
in assessing potential hazards of certain
organic compounds even if present in
minute amounts in drinking water.
12. Assessment of Occupational Hazards
to Operators of Wastewater Renovation
Facilities.
Besides the hazards of exposure of
workmen to chemicals related to the chlor-
ination process, hazards of exposure to
ozone or U.V. light should be considered
in case these alternate routes are to be
initiated.
13. Development of Channels of Communica-
tions and the Rapid Dissemination of
Data.
Recommendations for Exchange of Informa-
tion on Organic Pollutants in Water
(1) A brief international newsletter
should be published periodically
(bimonthly ) containing sub-
mitted summaries of research
being conducted or planned in
the areas of identification,
fate, and effects of organic
pollutants in water or waste-
water. Submissions should be
solicited from all researchers
in the area by appropriate
advertisement. The purpose
should be rapid dissemination
of research results or intention
before open literature publica-
tion.
(2) A second international news-
letter, to be published quarterly,
maybe even briefer than the
first, should be designed for
the tabulation of specific
. organic compounds identified in
any water or wastewater, listing
sources of the pollutant, con-
centrations, method of analysis,
degree .of confirmation, and very
concise toxicity and organoleptic
data, ^he first newsletter of
this type should include copies
of all existing lists of pollu-
tants; e.g., the Project 646
list, the WHO water reuse con-
ference (]975) list, the various
EPA lists, etc. Information in
these newsletters should be
combined in about a year into a
computerized master list of
pollutants in water. If new
compounds are identified by mass
spectrometry, the spectrum
should be submitted and forwarded
to the EPA for inclusion in the
NIH-EPA mass spectral search
file.
14. Development of International Cooper-
ation and Coordination.
It is recommended that efforts in
the direction of evaluating the health
effects of organics in water for direct
or indirect wastewater reuse for potable
purposes be coordinated on an international
basis with such agencies as the Inter-
national Reference Center on Community
174
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Water Supplies of WHO, the European com-
munity, and specific countries directly
involved in such endeavors. To the
extent possible, test procedures for
identifying organics should be standard-
ized so that comparable results can be
obtained on water sources from various
parts of the world. Sampling methods,
techniques for concentration, toxicological
screening methods, and long-term toxico-
logical testing programs should also be
standardized and coordinated internation-
ally. The output from the various inter-
national programs should be integrated
and disseminated on a regular basis to all
participants of the program.
Workshop Participants:
Gary P. Carlson - University of Rhode
island, Kingston, Rhode Island.
Robert B. Dean - AWTRL, US-EPA, Cincinnati,
Ohio.
Hans L. Falk - Chairman, NIEHS, Research
Triangle Park, North Carolina.
A. W. Garrison - EPA, Athens, Georgia.
Cheng-Chun Lee - Midwest Research Insti-
tute, Kansas City, Missouri.
Perry McCarty - Stanford University,
Stanford, California.
Gordon W. Newell - Stanford Research
Institute, Menlo Park, California.
Raymond E. Shapiro, Epid. Unit, DHEW-PHS,
Washington, B.C.
Hlllel I. Shuval - Hebrew University,
Jerusalem, Israel.
Marshall Steinberg - U.S. Army Environ-
mental Hygiene Agency, Aberdeen
Proving Ground, Maryland.
Robert G. Tardiff - Vice-Chairman, EPA,
NERC, Cincinnati, Ohio.
B. Cees J. Zoeteman - WHO International,
The Hague, The Netherlands.
DISCUSSION
COMMENT: Mr. Jack Glennon, U.S.
Army Medical Research Development Com-
mand, Washington, D.C. I just want to
make a comment here on a potential
problem. You've got a pretty good out
in your last paragraph here: "To the
extent possible, test procedures for
identifying organics should be stan-
dardized." I am assuming you are
talking about international standard-
ization here. When I was in Paris last
fall, various people from EPA presented
their GCMS capabilities, and the people
from Europe just stood there in awe.
They just don't have this type of
capability and they don't have the
resources to get into this. So, I think
the discrepancy between the quality of
the data from international studies and
the quality of the output from inter-
national studies could be a severe
limitation.
RESPONSE: Mr. Falk, NIEHS, Research
Triangle Park, North Carolina. We have
a gentleman from Holland here who might
be able to give some comment on that.
Could you? '
COMMENT: Mr. Zoeteman, WHO Inter-
national, The Hague, The Netherlands.
1 certainly was not at this meeting.
Currently, I think quite an effort is
going on in Europe to identify organics
in waters. The Commission of the
European Community started only recently
to coordinate this work, and they
identified quite a number of compounds.
Certainly, we agree that you here in
the United States started in this field
some years before we did. But I think
that cooperation in the future would
certainly be of mutual benefit.
COMMENT: Mr. Dean, AWTRL, US-EPA,
Cincinnati, Ohio. I would like to
respond to Jack Glennon. I agree that
we have more mass spectrometers in this
country, but the better labs in both
countries are comparable. Werner Stumm
was telling me of his capabilities. He
has opened up a complete "quantum jump,"
as he said, in the ability to analyze
compounds. There are very capable
laboratories in Europe and we shouldn't
run them down.
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COMMENT: Moderator Robeck, Water
Supply Research Laboratory, Cincinnati,
Ohio. I don't think that was Jack's
intent.
RESPONSE: Mr. Glennon, U.S. Army
Medical Research Development Command,
Washington, B.C. No. Just let me clear
my conscience here. The main point I
wanted to make is that the financial
resources to invest in these types of
facilities, especially when the state of
the art is advancing so fast that by the
time you get your mass spectrometer in it
has passed you by, can be a real problem.
COMMENT: Moderator Robeck, Water Supply
Research Laboratory, Cincinnati, Ohio.
I would like to emphasize that we want to
get quantitative data wherever possible.
We have been looking at this well-
identified list for a long time, but it
hasn't been too satisfactory.
COMMENT: Mr. Goldsmith, National Cancer
Institute, NIH, Bethesda, Maryland. I
am enthusiastic about getting good
analytic work on both organic and in-
organic materials in water supplies, and
I know that this is a prerequisite to
adequate health effects studies. But I
am troubled about the necessity of
including the consideration of analytic
procedures in panels on health effects.
I suspect, and I am anxious about the
possibility that this may reflect a program
decision which, if it were being made,
would be made erroneously- I think it is
extremely important to establish analytical
procedures and determine what materials
are present in water systems because of
the necessity for evaluating the health
responsibilities. Possibly we should even
consider rewriting the organization of the
material which has been considered to
include a section on analytical procedures.
However, I am reluctant to see this
included as part of the health effects
program in program budgeting and manage-
ment. I think if we are not careful we
will use up all the resources which have
always been scant for health effects
studies, for the great satisfaction of
improving sensitivity, validity, relia-
bility, and identification of some new
agent which may be very important for
health purposes. I think that this is a
separate program responsibility, and I
am warning my colleagues that if this
is not isolated and kept within a
separate budgetary and administrative
category, we are going to find our-
selves without support for health
effects research.
RESPONSE: Mr. Falk, NIEHS, Research
Triangle Park, North Carolina. In our
discussions throughout the days, we
were always basing our biologic test
procedures and the need for various tests
on the basis of having identified com-
ponents in whatever we tested. We held
a long discussion on the need to test
fractions that were subfractions of
actual concentrates, and had a great
deal of difficulty because of some of
the changes, losses and alterations that
would occur. Therefore, many of our
tests would be carried out on compounds
that are pure and that have been
identified as components.
COMMENT: Moderator Robeck, Water Supply
Research Laboratory, Cincinnati, Ohio.
We are very conscious of this, Dr.
Goldsmith, and our approach to it is
to put the health effects people in
charge of the overall mission so that
they can control the matter of how much
goes into analytical development to
suit their programs. In that way, you
don't have an "ivory tower" of refine-
ment perhaps beyond their needs. I
hope that this approach works.
COMMENT: Mr, Marshall Steinberg,
U.S. Army Environmental Hygiene Agency,
Aberdeen Proving Ground, Maryland. I
accept what Dr. Goldsmith says, but I
think we should take a lesson from
standards established in the past, and
not necessarily water standards, where
a standard was established on the basis
of the analytical technique that was
available. This is not to say that it
was tied to the fact that we could
measure it, but that the number has a
direct bearing on your ability to re-
produce your data. And to generate a
lot of human data which requires the
analytical support of one method and
then, a short time later, apply a new
analytical technique to the measuring
may either produce a situation in which
your constraints are too tight or, in
fact, not tight enough. I think the
industrial hygiene field is living with
this problem today.
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COMMENT: Mr. Christian, University of
Cincinnati, Cincinnati, Ohio. I was very
pleased to see the inclusion of your work
on in vitro systems. One thing that
rather concerns me is that they are usually
talked about as screening systems. I
think that they can be most useful when
integrated with the total toxicological
input and not used merely to look for a
specific fact. I think perhaps some of
the systems have limited usefulness if
they are not integrated with animal
sys terns.
COMMENT: Mr. Middleton, NERC, US-EPA,
Cincinnati, Ohio. I would just like to
make the comment that we have to keep very
much in mind, with all of this analytical
talk, the quality assurance and validity
of our own data. It is very hard, as we
have all found out just in one country,
to have assurance that the data are com-
parable from one laboratory to another.
It is triply difficult if we do it on an
international basis. However, there is
a tremendousnecessity for us to be sure
that our analytical data are valid and
that they have quality assurance built
into them. Otherwise, we have a lot of
things that we can't compare.
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WORKSHOP ON SOCIO-ECONOMIC ASPECTS OF POTABLE REUSE
Chairman: E. G. Altouney, National Oceanic Atmospheric Administration
Vice-chairman: Richard K.. Schaefer, EPA, Washington Environmental Research Center
INTRODUCTION
It was the consensus of the group
that in general, the research needs for
Socio-Economic Aspects of Potable Reuse
are of a lesser priority than the health
aspects.
In considering the socio-economic
aspects of potable reuse it should be
pointed out that much of the water sup-
plies currently furnished contain signi^
ficant amounts of wastewater from upstream
communities. This indirect reclamation
and reuse should be recognized in that
quality standards for water supplies and
wastewater reuse for potable purposes
should be the same.
In addition there are many areas of
reuse other than potable that should be
recognized as important extenders of the
community water supplies. These other
reuse aspects still present problems
relating to acceptability. For example,
use of treated wastewater for agricultural
purposes presents concerns to agricul-
turists over crop yield reduction as a
result of build-up of salinity levels and
critical trace elements over long periods
of time. Such concerns are also valid
when irrigation water ultimately infil-
trates into a groundwater basin which
serves other uses. Even though the group
identified health aspects of wastewater
reuse as paramount in importance, the
following projects were identified as
meriting investigation by descending
order of priority.
1. National Survey and Local Investiga-
tion of Areas of Water Recycling
Feasibility (High Priority)
A. SPECIFIC RESEARCH NEEDS
1. To identify the extent to
which the U.S. population
is presently being supplied
former wastewater as part
of their raw water supply.
2. To select up to 10 (ten)
U.S. locations of varying
characteristics and conduct
an in-depth investigation
of potential reuse cost-
effectiveness.
B. DISCUSSION
1. Reason for Specific Research
Needs
a. In most areas of the
United States, water
utilities are dealing
with an ever-increasing
degraded water supply
of which the health
aspect studies relating
to this practice have
not been faced or the
relationship to this
aspect of water use and
its correlation with
direct and indirect re-
use set forth.
b. It is recognized that
local factors such as
size, industrialization,
climate, etc., have a
significant effect upon
the economics, or cost-
effectiveness, of reuse.
It is considered impos-
sible to provide mean-
ingful answers to the
economic uncertainties
178
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on a national scale,
however, if typical
"types" of different
areas were properly
selected, then case
studies of cost-effec-
tiveness would be impor-
tant.
2. Suggested Approach to the
Problem
We would like to see EPA
design a study and carry it
out in general accordance
with the following approach:
a. Number of cities using
sewage water in their
raw water supply.
b. Estimate the population
drinking water composed
of sewage water.
c. Develop a curve showing
(a) and (b) above for
the,last 20 years and the
next 25 years.
d. Quantify the percent of
sewage in our nation's
raw water supply in the
years 1950-2025.
e. Estimate the percent of
direct and indirect
potable reuse over the
next 50 years ±.
f. Identify those regions,
areas, and communities
of the nation which will
soonest require serious
consideration of reuse to
supplement existing water
resources. It is ber-.
lieved that this task
could be accomplished by
analysis of a variety of
existing national survey
data, supplemented by a
limited additional amount
of new developmental
effort.
A number of these loca-
tions should be selected
for in-depth investiga-
tion of reuse potential.
Selection criteria
should ensure that im-
portant variations (from
a reuse economics and
cost-effectiveness point
are considered. Such
criteria might include:
(1) Size, population,
and other demogra-
phic variations. It
is recognized that
economics, for ex-
ample, vary signi-
ficantly between
areas of different
size.
(2) Degree of industrial-
ization (with empha-
sis upon high water
consumption industry)
and irrigation de-
mand (agriculture,
golf courses, pas-
ture, and other major
irrigation water
users). Also, ex-
tent to which land
use controls have
concentrated indus-
trial , agricultural,
residential users in
specific areas.
What is being sought
in this criterion is
to differentiate
between an area
where separate dis-
tribution is fea-
sible, e.g., Odessa,
Texas, from large
metropolitan areas
where separate dis-
tribution is not
feasible, e.g.,
Denver, Colorado.
(3) Options available
with regard to in-
direct reuse if any,
e.g., is geology
amenable to ground
water recharge, is
there a large storage
179
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3.
lake for storage and
dilution, or is di-
rect reuse the only
feasible option?
(4) Geographical location
(5) Climatological dif-
ferences .
h. The in-depth investiga-
tions in each of the
selected locations should
include at least the
following:
(1) At what points in
time and water demand
will the use of
wastewater become
economic, or cost-
effective for each
of the types of reuse
including potable.
In other words,
develop an economic
hierarchy of succes-
sive types of reuse.
(2) To accomplish this,
a series of supply-
demand curves related
to time is required.
These curves are
based upon population,
consumption, etc.
projections.
(3) An evaluation of the
water supply, waste-
water disposal, water
reuse situations
present and future
from a total systems
perspective.
(4) Legal ramifications.
Suggested Length of the Study
is One Year, with 3-4 Man-
Years of Effort.
2. Public Education on Current Indirect
Water Recycling
Determine how the public, most of
whom currently are using some reclaimed
water in their domestic supply, can be
informed of this in such a way that they
will understand and accept it.
Reason for Specific Research Need
In discussions on direct reuse and
what is needed to practice it safely,
the fact that many so-called "virgin"
water sources have for years contained
significant quantities of wastewater has
all but been ignored. Even direct reuse
will involve some dilution within the
distribution system. Therefore, in
reality, so-called direct reuse would
not introduce a completely new product.
Thus, if the people already receiving
a significant amount of reclaimed water
in their potable supply could be shown
and convinced that 'it posed no signifi-
cant use problem, it would be relatively
easy to show them that an increased
amount of reclaimed water, after treat-
ment to assure its quality, meets
established goals.
Suggested Approach to the Problem
Conduct educational programs de-
scribing a number of cities that have
for many years used source water con-
taining varying percentages of wastewater.
Determine whether or not there have been
major health effects and a high number of
customer complaints, 'the. cities included
in the study would have to be those
producing a water of relatively high
quality.
If the results of the study were
favorable, the fact that the community
had been using reclaimed water for years
without adverse effects should be given
to the people (in different ways in
different cities) to determine their
reaction. The most satisfactory ap-
proaches could then be used in com-
munities finding it necessary to increase
the percentage of reclaimed water di-
rectly or indirectly. Length; Undeter-
mined .
180
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3. Analysis of Legal Considerations of
Water Rights Affecting Reuse (Medium
Priority)
Recycling of municipal wastewater <•
has the potential of impacting the quan-
tities available for upstream and down-
stream water users. Individual state
water laws will be interpreted, modified,
or both, to accommodate the.implementation
of .treated municipal wastewater reuse.
/
Identification of significant legal
precedents which could constrain the
implementation of such reuse;is needed. -
This should be approached on a state-by-
state basis in that water laws vary from
state to state. •.-•< ,, •>- ^
The 'respective legal aspects could
change the present type of water use so " '
that users requiring higher quality sup-' -
plies could receive them, rather than
having to resort to reuse. In addition,
the level of treatment could be vastly
different if such exchanges of water could
be effected.
Analysis of the impact of such re-
ordering of water uses could lead to
identification of potential changes in
existing water law. Eength: Three L
person-months. (Note: Denver Research
Institute is doing some of this.) •:••:•!..•'
4. Analysis of Legal Considerations of
Liability for-Distribution'of Re-
cycled Water (Medium Priority)
Identification of sphere of impact
when treated municipal wastewater is being
considered for potable uses is needed.
Numerous regulatory entities exist
that may have jurisdiction over various
water-consuming activities within a given
area. Identification of such agencies
and delineation of their respective re-
sponsibilities and pertinent legislation,
initially at the federal level, would
provide water purveyors with an array of
information which could assist them in
becoming alerted to standards, regula-
tions, and legislation that could con-
strain the potable reuse of treated
municipal wastewater.
This is necessary in that the im-
pact of potable reuse will not only be
limited to direct human consumption, 's
but also to industries such as food and
beverage processers.
The environmental assessment could
lead to considerable litigation if the
appropriate standards, regulations, and
legislation are not adequately addressed.
Length: One person-year-;-- ...
5. Analysis of'Value of Water.Quality
to Consumers (Medium Priority) -j . .
Statement of Need
'Basic economic data are needed on
the value of a certain level of water
quality to the consumer. That is, how .
much money is the average household
consumer willing to pay for a higher
level of water quality?
Discussion
Most municipal water treatment
investment decisions are made by pro-
fessionals based on their beliefs ,as to
the value of a certain watef quality
level, or are made indirectly by con-
sumers who vote on bond issues for new
treatment facilities. The planning
process would be significantly advanced
if data were available on the perceived
value of a higher quality water over
another quality. This is particularly
germane to decisions to implement re-
cycling now, 'or to wait until technology
is farther advanced, or to develop more
expensive conventional supplies.
One suggested approach would be to
measure consumer behavior directly
related to water quality: (a) pur-
chasing of bottled water by consumers
as a function of income or socio-
demographic characteristics; (b) pur-
chases of home water-softening equipment;
(c) comparative value of homes which
differ only in quality of water service,
if such can be found.
A study of (a) could be done in 5-6
person-months, from supermarket data on
bottled water sales, related to census
tracts, in a single water system. A
study of (b) could be done by survey and
would require 10-12 person-months.
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6. Incentives to Cooperation Between
Water Supply and Wastewater Agencies
(Medium Priority)
Statement of Need
Conduct a study of the methods and
effects of various methods of encourage-
ment that can be exerted by funding and
regulatory agencies on separate water
supply and wastewater treatment entities
to get them to coordinate their efforts
in water management programs that include
reuse.
Discussion
In many areas the water supply and
wastewater treatment entities are separate
units. This has resulted in some problems
of cooperation and coordination in de-
veloping water management programs that
include reuse. More specifically the
problems included jurisdiction (which
agency should be the lead one) and eco-
nomics (who was to pay what portion of
allocated costs). In the case of appar-
ent lack of cooperation and coordination,
encouragement from funding and regulatory
agencies can be potentially effective in
bringing about effective water management
programs. The various methods of en-
couragement and the results of these
methods should be investigated.
This study could be conducted within
about one year, using 2.5 man-years.
7. Determine Acceptable Proportion of
Recycled Water (Medium Priority)
Statement of Research Need
Determine, under varying sets of
circumstances, the proportion of reclaimed
water the public will accept in their
domestic water supply.
Discussion
Through the different communities
of the nation many different circumstances
exist, and what may be appropriate for
one area would be inappropriate for
another. It would be helpful to have
guidelines established which a local com-
munity could apply to its situation to
determine its optimum alternate in de-
veloping a reclaimed water program. Such
guidelines should provide both engineer-
ing and customer attitude data which
would enable the comparison of items
such as costs of higher treatment of
wastewater vs. delivery of a safe but
lower quality of water; increased use
of reclaimed water vs. water conserva-
tion; increased use of reclaimed water
vs. development of alternative "natural"
supplies (icebergs, interbasin transfers,
de-salting of ocean water, etc.). Length
of Study; One year, using 1.5 person-
years .
8. Problems Faced by Cities Pioneering
Reuse -(Medium Priority)
Statement of Heed
Determine and forecast relative
importance of types of sociological,
institutional, and economic problems
that will be faced by cities pioneering
potable wastewater reuse.
Discussion
There is considerable evidence
that public attitudes, based on deep-
seated cultural taboos, oppose..drinking
recycled wastewater. This attitude
persists despite objective evidence
that "accidental" or indirect reuse,
equal in contamination to direct reuse,
is common. Further, the attitude is
likely to persist to some degree even
though scientific proof establishes that
recycled water is e.qual to or superior
to "fresh" water.
The problem faced by a pioneering
city is that of public attention lead-
ing to scorn, for violating this taboo.
Even though residents of the city may
accept reuse, there is the possibility
that other persons who have a free
choice—e.g., tourists, convention-goers,
persons who can choose between food and
beverage products produced in the pioneer
city or elsewhere—may irrationally
treat the pioneer city as outcast. What
action would successfully overcome these
problems, e.g., educational campaigns?
The suggested approach would be to
develop case studies from other cities
which pioneered violation of cultural
taboos to determine the reaction, and
specifically to study public attitudes
toward cities where a health problem—
182
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real or imagined—existed to determine
behavior patterns. Has there been any
evidence of a reduction of tourist busi-
ness or a boycott of products? After case
studies are written, an interpretive
analysis can be made, based on similar-
ities in behavior, etc. Length; A 6-8
month study seems adequate; perhaps 15-18
person-months.
9. Socio-Economic Impact of Delay of
Water Recycling (Medium Priority)
Statement of Need
Develop an assessment of the social
and economic impacts on a municipality
in case scheduled implementation of potable
reuse is unexpectedly delayed and the
implementation of contingency plans
becomes necessary.
Discussion
A number of cities are proceeding to
develop water recycling technology on
the assumption that recycling for potable
use will become feasible in another 15
years or so. The problem which could
arise, however, is that public health
hazards may not, after all, be overcome
when scheduled. The possibility exists
that a legal injunction may be granted,
on the request of health experts or even
environmental groups, which bars operation
of the recycling plant.
If the city has abandoned development
of conventional supply sources in anti-
cipation of successful reuse, it cannot
reverse strategy and develop these sources
for some time. Instead the city would
probably face forced conservation, the
construction of dual systems for non-
potable distribution, and a crash program
of development of conventional water
supply sources.
The suggested approach would be to
select several cities for analysis, and
simulate the impact of this disruption
by assuming a certain percentage drop in
water supply. The social and economic
costs of the resulting impact can be
estimated in terms of a forced reduction
in consumption, and engineering estimates
of the cost of developing a dual distri-
bution system and/or replacement supplies
can be projected. Each such impact can
be stated in terms of present value. The
cost of the forced reduction in consump-
tion can be simulated by using estimates
of price elasticity for water; i.e.,
how high a price increase would reduce
household consumption by the same amount
as the forced reduction. Length: The
study would involve about 4 person-months
plus 3 person-months for each city ana-
lyzed.
10. Study of Diffusion of Water Re-
cycling to Other Cities (Low
Priority)
Statement of Need
Determine the likelihood and extent
to which sociological, institutional
and economic problems faced by cities
practicing potable use of wastewater
will diminish, as more and more cities
adopt this practice.
Discussion
There does not appear to be any
diversity of expectation here. Observa-
tion and perhaps history shows that as
innovations increasingly become adopted,
resistance to adoption eases.
This is rather well documented by
the literature on technology transfer,
e.g., Havelock's work at Michigan and
the pioneering work of Everett M. Rogers,
in Diffusion of Innovations, dealing with
hybrid seed corn, medical detailing, etc.
The suggested approach would be to
apply innovation diffusion experience to
matters akin to water recycling to see
if the historic lessons are applicable.
Examples of analogous situations should
be given. Length; A 4-6 month study
(some 7-8 person-months) seems adequate
for a start—perhaps to completely
research the subject.
Workshop Participants:
George W. Adrian - Los Angeles Department
of Water & Power, Los Angeles,
California.
Edward G. Altouney - Chairman, Marine Eco-
Systerns, NOAA, Boulder, Colorado.
183
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Lloyd C. Fowler - Santa Clara Valley
Water District, San Jose, California.
Stephen Heare - Arlington, Virginia.
Kenneth J. Miller - Denver Water Depart-
ment, Denver, Colorado.
J. Gordon Milliken - Denver Research
Institute, University of Denver, Denver,
Colorado.
Richard K. Schaefer - Vice-Chairman,
EPA, Washington Environmental Research
Center, Washington, D.C.
Curtis J. Schmidt - SCS Engineers, Long
Beach, California.
William Seeger - Kennedy Engineering,
Inc., San Francisco, California.
Elroy F. Spitzer - AWWA Research Founda-
tion, Denver, Colorado.
Roger A. Wiedelman - Bureau of Reclamation,
Denver, Colorado.
Rocky Wiley - Denver Water Department,
Denver, Colorado.
APPENDIX
In addition, the group recognized
that it would be highly desirable for
EPA to undertake a study dealing with
the development of a viable and operable
water conservation program for use by
utilities.
Discussion
The general public over the years
has been led to believe that there was
an unlimited supply of water available.
Recent experiences coupled with present
and future population growth indicated
that in order to provide adequate supply
we cannot depend on the "unlimited supply
syndrome" of the past. Due to the "un-
limited supply" attitude that has existed
the American public has unconsciously
become very wasteful of water. A possible
supplemental supply can, with, adequate
future research, be- provided by wastewater
reuse but at a relatively high cost. In
view of the fact that our present sup-
plies are more economical it is imperative
from an economic standpoint that existing
supplies be conserved to the greatest
extent possible within the present "life
style" of the community. In the past
many agencies have developed "Water Con-
servation Programs" that can be useful
and helpful to agencies being threatened
by water shortages.
We feel that a Survey program
directed to a review and compilation of
the various programs in order to bring
all information into one central loca-
tion will provide great benefit to the
American public.
In order to fully implement a
successful water conservation program it
would be desirable to conduct an
"Attitudinal Survey" to evaluate con-
sumer acceptance of a Water Conservation
Program in a particular area. Such a
survey would require the following two-
stage approach:
1. Develop an evaluation of the
impact of a broad water conser-
vation program which reduces
demand load and reduced patterns
of usage of potable water
supplied to buildings/occupants/
residents.
2. Conduct an assessment of accep-
tance and implementation of
innovative water system appli-
ance and fixtures in dwellings
and commercial buildings (e.g.,
dwelling storage of water from
baths, showers, dishwashers and
washing machines for flushing
toilets) which alters flow into
and from wastewater treatment
plants.
DISCUSSION
COMMENT: Mr. Schmidt, SCS Engineers,
Long Beach, California. I just wanted
to comment that with respect to research
project No. 5, which is "Analysis of
Value of Water Quality to Consumers,"
I don't believe that the group intended
that we think of water value only in
terms of the household consumer. We
were interested in water value to all
types of consumers.
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RESPONSE: Mr. Altouney, Marine Eco Sys-
tems, NOAA,Boulder, Colorado. That's an
extension. I think it was indicated
earlier in the presentation that we felt
that not only potable reuse was deserving
of additional research but also extended
uses of recycled wastewater. We identi-
fied agriculture and, of course, there
are other areas, too.
COMMENT: Moderator Robeck, Water Supply
Research Laboratory, Cincinnati, Ohio.
I suppose you would mean even in a city
context, wouldn't you, Mr. Schmidt? In-
dustrial use, for instance.
RESPONSE: Mr. Schmidt, SCS Engineers,
Long Beach, California. Yes. That's
what I had in mind.
COMMENT: Mr. Dryden, Sanitation Dis-
trict of Los Angeles County, Whittier,
California. You commented on the agri-
cultural use and expressed concern about
factors such as the TDS of the water
causing problems in the soil. Although
that is true,it doesn't seem to me that
that is uniquely related to recycled
water. Natural water supplies with high
TDS have the same problem. These are
pretty well understood by people in
agricultural fields, and you can deter-
mine before you use the water what kind
of problems you are going to have, and
whether it is suitable for soils you are
applying it to, the crops you are apply-
ing it to, and so forth. I think that
it is a general problem, and certainly
not unique to water reuse.
RESPONSE: Mr. Altouney, Marine Eco
Systems, NOAA, Boulder, Colorado. That's
a well-taken point.
COMMENT: Mr. Dean, AWTRL, US-EPA,
Cincinnati, Ohio. With respect to your
point number 3, related to the legal con-
siderations and the fact that you might
be able to change the water laws, I would
like to refer to a bit of history. Back
in 1930, we had an advanced waste treat-
ment program going on in Los Angeles with
reused water—which was reported by
Goudy. The purpose, according to Goudy,
was to show that you could treat waste-
water and make it usable again, and he
succeeded. The real purpose was to get
the people of Los Angeles so mad that they
would vote the bond issue to bring in
Colorado River water.
Is there a danger that the development
in Denver is merely to change the water
laws in the State of Colorado so that
Denver, which has a large population,
will get more of the water, and the
agricultural land barons won't get the
water they think they own.
RESPONSE: Mr. Altouney, Marine Eco
Systems, NOAA, boulder, Colorado. Per-
haps I should refer the answer to this
question to Ken Miller.
COMMENT: Mr. Spitzer, AWWA Research
Foundation, Denver, Colorado. He has
gone.
RESPONSE: Mr. Altouney, Marine Eco
Systems, NOAA, Boulder, Colorado. I
might answer this question in generali-
ties. I think the National Water Com-
mission came up with some very strong
recommendations concerning study of the
rationale behind our current legal water
rights to see if they are still appli-
cable in the twentieth and twenty-first
centuries. The water laws worked well
in the early years, but it seems that
there is a growing feeling among con-
cerned people in the water resources
field that a fresh look at our legal
water rights is called for. Now,
whether, in specific circumstances,
actions that are now under way are
designed to force any such reassessment
of legal matters is beyond me. I really
don't know.
COMMENT: Moderator Robeck, Water Supply
Research Laboratory, Cincinnati, Ohio.
It is a very interesting concept, none-
theless. Mr. Schmidt, do you have
another comment?
COMMENT: Mr. Schmidt, SCS Engineers,
Long Beach, California. Yes. I wanted
to comment on Frank Dryden's statement.
Frank is absolutely correct in stating
that the farming profession knows a
great deal about the application of TDS,
sodium, and some of the other common con-
stituents in irrigation water. We were
concerned more with the up-take by
potable crops of some of these consti-
tuents we know less about. In other
words, without any question, there will
185
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continue to be a great deal of irriga-
tion with reclaimed wastewater, and s'ome
of the same questions which are coming
up about its use in drinking water may
also be of concern in terms of edible
crop uptake of these constituents.
RESPONSE: Moderator Robeck, Water Sup-
ply Research Laboratory, Cincinnati, Ohio.
I think that we all recognize that. I
think Frank meant that it is outside the
context of this particular conference
perhaps.
COMMENT: Ms. Gorchev, EPA, Washington,
D.C. I am not so sure if health effects
studies should be given a higher priority
than the socio-economic ones. I feel
that unless you tell us that this prac-
tice would be socially accepted, and that
it is economically needed and feasible,
there shouldn't be any need to do health
effects work.
RESPONSE: Mr. Altouney, Marine Eco
Systems, NOAA, Boulder, Colorado. This
is a very good point. We have addressed
it at length, and I gathered from the
discussions that if the health effects
were fully studied and understood, our
socio-economic problems would vanish. In
other words, the feeling of safety that
is lacking relates to the health aspects.
So, we cannot go around selling a program
on which we, ourselves, are not sold. If
we fear the health consequences of certain
viruses, pathogens, whatever you want
to call them, we cannot go around and
try to sell it to the people.
So, as a group, we have expressed a
concern that increasing amounts of re-
cycled wastewater are going into the sys-
tem without the full knowledge of the
consumers. We felt that we need to do a
lot more in the area of health to deter-
mine the consequences of using recycled
water for potable purposes.
So, I agree with you. It's like the
chicken and the egg. However, we feel
that the health aspects are probably para-
mount. We would not suggest that socio-
economic research should not be done at
this time, although we feel the priority
is somewhat lower.
RESPONSE: Moderator Robeck, Water
Supply Research Laboratory, Cincinnati,
Ohio. In other words, I think we'll
move ahead together.
COMMENT: Mr. Willard R. Chappell,
Director, The Molybdenum Project,
University of Colorado, Boulder, Colo-
rado. I want to introduce a couple
more complications, that perhaps were
included in your thinking. At least in
the Southwest, a number of things are
going to be interconnected with water
use. One of those is the energy indus-
try which in this state, and I am sure
elsewhere in the Southwest, is likely
to be limited by water supply more than
anything else. Of course, one also
interacts with agriculture in the sense
that everything we take out of the
Colorado River Basin increases the TDS
level in the Colorado River, and we all
know that that is a complicated issue
as well. So the socio-economic impact
is far beyond that of the individual
householder and relates to the energy
industry and the agricultural industry
as well.
COMMENT: Mr. Parker, Brown & Caldwell,
Walnut Creek, California. As we are
talking about priorities here, I would
like to contribute my own rating system
to these. I think they fall on the
extremes of high priority and low priority.
I think Numbers 1 through 6 help to
identify for us the potential market
for reclaimed water. Why are we stand-
ing here talking about reclaiming water
if we don't know what the need is?
How are we going to sell Congress that
they ought to spend $100 million over
the next fifteen years if we can't pro-
ject the need, and predict that we can
develop the institutional arrangements
for putting reclaimed water into the
system?
However, beyond Item 6, I think we
are getting into constraint problems—
problems that someone has created to
research. I think that they are truly
ones that we are going to find in indi-
vidual situations, but I don't think
the way those public agencies will solve
those problems will be pointed at in an
EPA report on some paper study in advance
186
-------
of those problems. My experience has
been that when people want to solve that
kind of problem, they talk to someone
who has solved that kind of problem. So,
if we are going to address issues such
as the acceptable portion of recycled
water, problems faced by cities pioneering
reuse, socio-economic aspects of delays,
studies of diffusion of water recycling
information, letts get case histories on
that. This is what is going to be valuable
to people. But that is something that is
in a long-range time frame. That is going
to be after we have practiced reuse. So
I would give those the very lowest of
priorities in this group.
RESPONSE: Altouney, Marine Eco
Systems, NOAA, Boulder, Colorado. Thank
you for your comments.
COMMENT: Mr. Milliken, Denver Research
Institute, Denver, Colorado. One further
comment. I hope it will not be a mis-
understanding of our group's comment
relating to the paramount priority given
health effects. I think it is true that
unless health effects ultimately are found
not to be a constraint, we will not at-
tempt recycling. But I take a little bit
of an issue with Dr. Altouney's comment
that if health effects are solved, the
socio-economic problems disappear. I
don't think they do. I think that is
just the beginning. If you remember
Elroy Spitzer's comment this morning, he
was concerned about the low priority given
to aesthetics. There was nothing in the
health effects about aesthetics, but
aesthetics can kill a bond issue, and
that is what is going to pay for the re-
cycling facilities.
So it was certainly my feeling, and I
believe it was shared by the group, that
we do need to maintain some funding of
socio-economic research, even though the
health effects are the one critical point.
RESPONSE: Mr. Altouney, Marine Eco
Systems, NOAA, Boulder, Colorado. Gordon,
I believe the choice of the words "will
disappear" was probably bad. Probably it
should have said "will be a lot easier
to solve."
RESPONSE: Mr. Milliken, Denver Research
Institute, Denver, Colorado. That is
certainly true.
COMMENT: Dr. Goldsmith, National
Cancer Institute, NIH, Bethesda, Mary-
land. I would like to suggest that the
introduction of this new technical pro-
cedure, which may effect health on a
widespread basis, is not the only time
in this generation or this century
that such things have happened. It
seems to me that we might be more
constructive in our approach to this
class of problems if we began to cate-
logue some of the other technical innova-
tions which carried with them a certain
amount of fear,a certain amount of public
anxiety, and so forth. One could list
some of these: the nuclear power, the
introduction of some of the pollution
control systems on automobiles, even the
construction of freeways if you are
willing to go back that far. I think
we have to take some lessons from this
class of experiences.
One of the things that seems pro-
minent to me in this collection of
experiences—and possibly fluoridation
is nearest to everyone's knowledge here—
is that there were conflicts and very
real ones between the judgments of
scientific and technical personnel and
the understanding of the basis of that
judgment and acceptability of it. It
seems to me we are going to be in the
same situation here. We have to deal
with the several levels of understanding
and perception. It does seem to me,
however, that in this one we have a
rather strong case in that this is a
problem in which the innovation is a
gradual one. We have experience in some
aspects of water reuse. It is just not
quite at the level of potable water
reuse. I would make an appeal to stress
the parallel experience with other
technical innovations which have similar
implications for public acceptability.
RESPONSE: Mr. Altouney, Marine Eco
Systems, NOAA, Boulder, Colorado. Thank
you.
COMMENT: Moderator Robeck, Water Supply
Research Laboratory, Cincinnati, Ohio.
One last comment.
COMMENT: Mr. Altouney, Marine Eco
Systems, NOAA, Boulder, Colorado. I
just wanted to comment that the first
187
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research project which we developed was
developed over some three pages of our
report and was not read. But that par-
ticular project did try to cover the
interrelationship between such things as
energy and cooling water uses, and dual
water, agriculture, and so forth. I
wanted to emphasize that we were not
ignoring that economic aspect.
COMMENT: Mr. Heaton, Denver Water
Department, Denver, Colorado. Just a
comment on Mr. Dean's remark. We are not
ashamed of our decision to investigate
potable reuse. It is not a bottora-of-the-
barrel decision or a last resort to us.
It is still one of the most viable, effi-
cient, and logical means we have of
increasing our future supply. However,
if California were to release its hold on
our water, that would be fine, too.
188
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PARTICIPANTS
George W. Adrian
Los Angeles Department of Water & Power
P.O. Box 111
Los Angeles, CA 90051
Edward G. Altouney
Deputy Director, Marine Eco Systems,
Analysis Program
NOAA
Boulder, CO 80302
Michael A. Bellanca
Virginia Water Control Board
P.O. Box 11143
Richmond, VA 23230
Edwin R. Bennett, Assoc. Professor
Department of Civil & Environmental
Engineering
University of Colorado
Boulder, CO 80302
Gerald Berg
Methods Development & Quality
Assurance Research Laboratory
NERC-EPA /
Cincinnati, OH/ 45268
Dolloff F. Bishop
U.S. EPA
National Environmental Research Center
4676 Columbia Parkway
Cincinnati, OH 45268
James R. Boydston
U.S. EPA
200 SW 35th
Corvallis, OR 97330
Carl A. Brunner
EPA, NERC, Advanced Waste Treatment
Laboratory
4676 Columbia Pkwy, Rm. 146
Cincinnati, OH 45268
Gary P. Carlson
Department of Pharmacology & Toxicology
University of Rhode Island
Kingston, R.I. 02881
Willard R. Chappell, Director
Molybdenum Project
University of Colorado, GAMOW 1033
Boulder, CO 80302
Robert T. Christian
University of Cincinnati
Kettering Laboratory
3223 Eden Ave.
Cincinnati, OH 45267
Neil M. Cline, Manager
Orange County Water District
P.O. Box 8300
Fountain Valley, CA 92708
John J. Convery
AWTRL, U.S. EPA
4676 Columbia Parkway
Cincinnati, OH 45268"
John T. Cookson
University of Maryland
Civil Engineering
College Park, MD 20740
Gunther F. Craun
EPA, WSRL, Inorganic Studies
4676 Columbia Parkway
Cincinnati, OH 45268
Robert B. Dean
AWTRL, U.S. EPA
4676 Columbia Parkway
Cincinnati, OH 45268
Franklin D. Dryden
Sanitation District of Los Angeles County
P.O. Box 4998
Whittier, CA 90607
189
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Stuart G. Dunlop
University of Colorado Medical Center
4200 E. 9th Ave.
Box B-175
Denver, CO 80220
Beatrice England
San Diego County Health Department
1600 Pacific Highway
San Diego, CA 92101
John N. English
EPA
4676 Columbia Parkway
Cincinnati, OH 45268
Hans L. Falk
NIEHS
P.O. Box 12233
Research Triangle Park, N.C. 27709
Don Felke
Tertiary Plant Foreman
811 E. Las Vegas
Colorado Springs, CO 80947
Russell Fitch
EPA Region VIII
1860 Lincoln, Suite 900
Denver, CO 80203
Lloyd C. Fowler
Santa Clara Valley Water District
5750 Almaden Expressway
San Jose, CA 95118
Lawrence Gallowin
National Bureau of Standards
Building 226, Room B 306
Washington, D.C. 20034
A.W. Garrison
EPA
SE Environmental Research Laboratory
Analytical Chemistry Branch
Athens, GA 30601
Jack Glennon
U.S. Army Medical Research
Development Command
Forrestal Building, Room 8F055
Washington, D.C. 20314
John R. Goldsmith
National Cancer Institute, NIH
7910 Woodmont Ave.
Bethesda, MD 20014
Hend Gorchev
EPA
401 MSR. S.W.
Washington, D.C.
20460
Daryl Gruenwald
Wastewater Treatment Superintendent
811 E. Las Vegas
Colorado Springs, CO 80947
Carl Hamann
Cornell, Howland, Hayes & Merryfield, Inc.
1930 Isaac Newton Sq. E., Room 202
Reston, VA 22090
Paul D. Haney
Black & Veatch
P.O. Box 8405
Kansas City, MO 64114
Richard D. Heaton
Denver Water Department
144 W. Coifax Ave.
Denver, CO 80202
Stephen Heare
Arlington, VA
Carl Houck
Black & Veatch Engineers
12075 E. 45th Ave.
Denver, CO
Roger Jorden, Assoc. Professor
Department of Civil & Environmental
Engineering
University of Colorado
Boulder, CO 80302
Charles W. Lee
Washington University Medical School
VA Hospital
John Cochran Division, Bldg. 3, Apt. E-l
915 Grand Ave.
St. Louis, MO 63106
Cheng-Chun Lee
Pharmacology and Toxicology
Midwest Research Institute
425 Volker Blvd.
Kansas City, MO 64114
R. E. Leffel
Camp, Dresser & McKee, Inc.
One Center Plaza
Boston, MA 02108
190
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Edwin H. Lennette
State of California
Biomedical Laboratories, Dept. of Health
2151 Berkeley Way
Berkeley, CA 94704
K. Daniel Linstedt, Assoc. Professor
Department of Civil & Environmental
Engineering
University of Colorado
Boulder, CO 80302
William Long
EPA
Washington B.C.
5205 Waterview Dr.
Rockville, MD 20853
Leland J. McCabe
Criteria Development Branch
Water Supply Research Laboratory
EPA,4676 Columbia Parkway
Cincinnati, OH 45268
Perry McCarty
Stanford University
Department of Civil Engineering
Stanford, CA 94305
Francis M. Middleton
NERC, U.S. EPA
4676 Columbia Parkway
Cincinnati, OH 45268
J. Gordon Milliken
Denver Research Institute
University of Denver
Denver, CO 80210
Kenneth J. Miller
Denver Water Department
144 W. Coifax Ave.
Denver, CO 80202
Gordon. W. Newell
Stanford Research Institute
333 Ravenswood Ave.
Menlo Park, CA 94025
p., M. Nupen
N.I.W.K. C.S.I.R.
P.O. Box 395
Pretoria, South Africa 0001
James L. Ogilvie
Denver Water Department
144 W. Coifax Ave.
Denver, CO 80202
Henry J. Ongerth
California Department of Health
2151 Berkeley Way
Berkeley, CA 94704
Miriam Orleans
University of Colorado Medical School
4200 E. 9th Ave.
Denver, CO
T. Panswad
Graduate Student (former)
4 Mankien 2
Huamark
Bangkok 24
Thailand
Denny S. Parker
Brown & Caldwell
1501 N. Broadway
Walnut Creek, CA 94596
Roland Rautenstraus
President
University of Colorado
Boulder, CO 80302
Charles H. Ris
EPA Industrial R & D
Industrial Pollution Control Division
Office for Environmental Engineering
Washington, D.C. 20460
Gordon G. Robeck
Water Supply Research Laboratory
4676 Columbia Parkway
Cincinnati, OH 45268
Joseph Roesler
EPA-NERC
4676 Columbia Parkway
Cincinnati, OH 45268
William Rosenkranz
EPA
401 M Street, SW
Washington, D.C. 20460
Herbert I. Sauer
Community Health & Extension
Environmental Quality
University of Missouri
307 Watson PI.
Columbia, MO 65201
Richard K. Schaefer
Washington Environmental Research Center
EPA
R.D. 690
Washington, D.C. 20460
191
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Curtis J. Schmidt
SCS Engineers
4015 Long Beach Blvd.
Long Beach, CA 90807
William Seeger
Kennedy Engineers,
657 Howard St.
San Francisco, CA
Inc.
Raymond E. Shapiro
Epidemiological Unit, DHEW-PHS
Food & Drug Administration
200 C Street, S.W.
Washington, D.C. 20240
Hillel I. Shuval
Director, Environmental Health Laboratory
Hebrew University
Jerusalem, Israel
Rexford D. Singer
University of Minnesota
1160 Mayo Memorial
Minneapolis, MH 55455
John M. Smith
EPA, NERC, Advanced Waste Treatment
Laboratory
4676 ColumMa- Pkwy, Rm. 146
Cincinnati, OH 45268
Sheldon 0. Smith
Environmental Conservation Programs
Nassau County Department of Health
240 Old Country Rd.
Mineola, N.Y. 11501
Stanley Smith
Water Division, EPA
EPA Region VIII
1860 Lincoln St.
Denver, CO 80203
Mark D. Sobsey
University of North Carolina
Chapel Hill, N.C. 27514
Clive C. Solomons
University of Colorado Medical Center
4200 E. 9th Ave.
Denver, CO 80220
Albert Soukup
U.S. EPA
Denver, CO
Elroy F. Spitzer
AWWA Research Foundation
6666 W. Quincy Ave.
Denver, CO 80235
Otis J. Sproul
Professor of Civil Engineering
University of Maine
355 Aubert Hall
Orono, ME 04473
Marshall Steinberg
Director, Laboratory Services
U.S. Army Environmental Hygiene Agency
Aberdeen Proving Ground, MD 21010
E. A. Swinton
Research Scientist
Australian C.S.I.R.O.
c/o Australian Embassy
Washington, D.C.
Richard Symuleski
National Bureau of Standards
Building 226, Room B 306
Washington, D.C. 20034
IJichael J. Taras
American Water Works Assn.
Research Foundation
6666 W. Quincy Ave.
Denver, CO 80235
Robert G. Tardiff
EPA, NERC, Water Supply Research
Laboratory
4676 Columbia Parkway
Cincinnati, OH 45268
Graham C. Taylor
Denver Research Institute
University Park
Denver, CO 80210
Vern W. Tenuey
EPA
100 California St.
San Francisco, CA 94111
Patrick Tobin
Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
A, C. Trakowski
U.S. EPA
Office of R & D, RD 676
Washington, D.C. 20460
192
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Craig Wallis
Professor of Virology
Baylor College of Medicine
Department of Virology & Epidemology
Houston, TX 77025
Roger A. Weidelman
Division of Planning Coordination
Bureau of Reclamation
P.O. Box 25007
Denver, CO 80225
Rocky D. Wiley
Denver Water Department
144 W. Coifax Ave.
Denver, CO
Harold Wolfe
Director '
Dallas Water Research Center
Dallas, TX
Richard L. Woodard
Camp, Dresser & McKee, Inc.
One Center Plaza
Boston, MA 02108
Stephen W. Work
Denver Water Department
144 W. Coifax Ave.
Denver, CO 80202
Robert L. Wortman
Oklahoma State Department of Health
Environmental Health Services
Oklahoma City, OK
Darwin Wright
EPA
401 M Street, S.W.
Washington, D.C. 20460
B. Cees J. Zoeteman
WHO International Reference Center for
Community Water Supply
Parkweg 13, The Hague
The Netherlands
193
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/9-75-007
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
Research Needs for the Potable Reuse of Municipal
Wastewater
5. REPORT DATE
December 1975
Tissuing Date")
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
K. Daniel Linstedt and Edwin R. Bennett
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
University of Colorado
Dept. of Civil and Environmental Engineering
Boulder, Colorado (80302)
10. PROGRAM ELEMENT NO.
1BB043 21-ASB Task 039
11. CONTRACT/GRANT NO.
Grant No. R803546-01
12. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory
Office of Research d Development
U.S. Environmental Protection Agency
Cincinnati, Ohio (45268)
13. TYPE OF REPORT AND PERIOD COVERED
Final 12/74 to 10/75
14. SPONSORING AGENCY CODE
EPA-ORD
15. SUPPLEMENTARY NOTES
16. ABSTRACT
The objective of the workshop was to define and establish priorities for researcl
needed to develop confidence in the reuse of wastewater for potable purposes. This
objective was accomplished by bringing together 92 select persons concerned with
wastewater reuse to discuss and identify research gaps in the areas of health effects,
treatment technology, and the socio-economic considerations of potable reuse. This
identified research will serve as a basis for future EPA projects.
The workshop was jointly sponsored by the Environmental Protection Agency (EPA),
the Water Pollution Control Federation (WPCF), the American Water Works Association
(AWWA), and was held in cooperation with the University of Colorado in March 1975,
at the Boulder, Colorado campus.
Reference: GAD No. R803546-01
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. cos AT I Field/Group
Water Reclamation
Water Conservation
Water Resources
Water Supply
Wastewater Renovation
Wastewater Reuse
Wastewater Treatment
Water Recycle
Reuse Technology
Domestic Reuse
Research Needs
Potable
13B
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)'
Unclassified
21. NO. OF PAGES
202
20. SECURITY CLASS (Thlspagej
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
194
ftUSGPO: 1976 — 657-695/5333 Region 5-11
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