UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON C C 20460
Deceitiber 11, 1986
Honorable Lee M. Thcwas
Administrator
U. S. Environmental Protection Agency
401 M Street, S. W.
Washington, D, C. 20460
Dear Mr. Thomas:
The Science Advisory Board's Water Quality Based Approach Research
Review Subcommittee has completed its review of the Agency's Water Quality
Based Approach research program and is pleased to forward its final report
to you.
The Subcommittee rat in public session on July 8-9, 1986 at EPA's
Environmental Research Laboratory in Duluth, Minnesota. Prior to its
meeting, the Subccnnuttee received a document prepared by the four EPA
laboratories that carry out research in this particular program and
entitled "Reference Material £or Science Advisory Board Review of Water
Quality Based Approach Cor the Control of Toxics - Freshwater,"
The major issues addressed by the Su&cotmittee included the following:
* Use attainability: application of the ecoregion concept.
* Development of water quality criteria and advisories: data require-
ments and utility,
• Effluent toxicity; practicability o£ toxicity limits, chemical
identification.
• Exposure; fluctuation, duration and frequency.
* Validation - Evaluations: national criteria, site specific
criteria and ecfluent toxicity.
• Waste load allocation: level of sophistication required,
• Methods standardization and accuracy: when is a method ready for
use?
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One of the Subcommittee's major conclusions is that methods tor
deriving water quality criteria have undergone a steady evolution and
extensive scientific review. These methods and the resulting criteria
have wide acceptance by the scientific and regulatory coraunities. Many of
the Subcommittee's recommendations are directed at further strengthening
the water quality based approach, and integrating it with work related to
other areas of toxic controls needing attention.
Thank you for the opportunity to present the Subcommittee's views on
this important research program. We request that EPA officially respond
to the scientific advice provided in this report.
Sincerely,
}
L- -
Kenneth Dickson, Chairman
Water Quality Based Approach Research
Review Subeowmittee
\\ ^T0" V • ' ' - -i
Norton Nelson, Chairman
Executive Commit t^e
Science Advisory Board
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SAB-EC-87-Q11
Review of IPA Water Quality Based Approach Research Program
by the Water Quality Based Approach
Research Review Subcommittee
of the
Science Advisory Board
December 11, 1986
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EPA NOTICE
This report has been written as a part of the activities of
the Science Advisory Board, a public advisory group providing
extramural scientific information and advice to the Administrator
and other officials of the Environmental Protection Agency. The
Board is structured to provide a balanced expert assessment of
scientific matters related to problems facing the Agency. This
report has not been reviewed for approval by the Agency, and
hence the contents of this report do not necessarily represent
the views and policies of the Environmental Protection Agency,
nor does mention of trade names or commercial products constitute
endorsement or recommendation for use.
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TABLE OP CONTENTS
I. INTRODUCTION /
A, Origins and Purpose of the Review !
8, Application of Research Program Results to
Regulation Development 2
c. Historical Development of Water Quality Criteria 4
II. CONCLUSIONS AND RECOMMENDATIONS 8
HI. WHOLE EFFLUENT APPROACH 13
W. NATIONAL WATER QUALITY CRITERIA GUIDELINKS/ADVISORIES 17
A. Background 1"?
B. Overview of l§85 Guidelines Approach to
Establishing Water Quality Criteria 17
C. Intensity (Exposure Concentration) 19
D. Duration (Averaging Periods) 22
E. Frequency 24
F. Aquatic Life Advisories 27
G. Selection of Chejnicals to Develop Criteria and 29
Advisories
V. VALIDATION RESEARCH j2
VI. USE ATTAINABILITY AND ECOREGIONS 34
VII. WASTELOAD ALLOCATION 40
VIII, METHODS STANDARDIZATION 42
A, Field Methods 42
B. Basic Biology of Test Organisms 43
C. Publication of Standardized Methods 43
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IX. AREAS RELATED TO THE WATER QUALITY BASED APPROACH Tn
TOXIC CONTROLS NEEDING ATTENTION
45
A, Nonpoint Sources
45
B. Technology Transfer
46
c. Sediments
4?
D. Biotechnology
49
E. Saltwater
49
F. Monitoring
V 50
x- LITERATURE CITED
ll
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O.S Environmental Protection Agency
Science Advisory Board
Water Quality Based Approach Research Review Subcommittee
Dr. Kenneth Didcscn, ehaisnan
Institute of Applied Sciences
North Texas State University
P.O. Box 13078 NT station
Denton, Texas 76203
Dr. Terry F. Yosie, Director
Science Advisory Board
U.S. l.P.A.
401 M. Street, S.W.
Washington, D,c. 20460
Dr. Harold Bergman
Dept. of Zoology 6 Physiology
University of Wyoming
University station Box 3166
Laraaie, Wyoming 82071
Dr. Jeffrey Black
School of Biological Sciences
University of Kentucky
101 Morgan Building
Lexington, Kentucky 40506
Dr. Richard Kiaerle
Monsanto Corporation
SOQ H. Lindbergh Blvd,
St. Louis, Missouri 63167-5842
Dr. John Neuhold
Dept. of Wildlife Sciences
College of Natural Resources
Utah State University
Logan, Utah 84322
Dr. David Maschwitz
Minnesota Pollution Control
Agency
1935 West County Road B-2
Roseville, Minnesota 55113
Dr. Thomas Waller
Dept. of Natural Sciences s
Mathematics
Environmental Sciences
University of Texas at Dallas
P. 0. Box 688
Mail Station SI-22
Richardson, Texas 75080
1X1
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I. INTRODUCTION
A. Origins and Purpose of the Review
At the request of IPA's Office of Research and
Development, the Science Advisory Board (SAB) has conducted a
series of reviews of its ongoing research programs. The SAB
reviews are conducted under the auspices of its Executive
Committee which has formed specific subcommittees of
qualified experts to address the scientific issues relevant
to each program. The purpose of these reviews is to peer
review of existing and planned scientific research, and to
communicate to the Agency's research scientists, program
office personnel and senior managers - including the
Administrator, Deputy Administrator and Assistant
Administrator for Research and Development - the progress, or
lack thereof, made in meeting research needs pertinent to the
development of regulations and policies,
The Executive Committee established the Water Quality
Based Approach Research Review Subcommittee to conduct the
review of EPA's water quality based approach for the
control of toxicants in freshwater. The Subcommittee met In
public session on July 8-i, 1986 at EPA's Environmental
Research laboratory in Duluth, Minnesota.
Prior to its meeting, the Subcommittee received a
document entitled "Reference Material for Science Advisory
Board Review of Water Quality Based Approach for the Control
of Toxics - Freshwater,11 and prepared by the four EPA
laboratories that carry out the research in this particular
program. These include the Environmental Research
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Laboratories in Athens, Corvallis, and Duluth and the
Environmental Monitoring and Support Laboratory in
Cincinnati, SPA staff also provided supplementary support
documents.
These documents fulfilled two functions: 1) summarizing
existing research and facilitating discussion of proposed
research and the future needs of the research program,* and 2)
identifying seven issues for the Subcommittee's review. The
issues presented included:
* Use attainability; application of the ecoregion
concept.
• Development of water quality criteria and advisories;
data requirements and utility.
* Effluent toxicity: practicability of toxicity
limits, chemical identification.
* Exposure: fluctuation, duration and frequency.
* Validation - Evaluations* national criteria, site
specific criteria and effluent toxicity.
* Waste load allocation: level of sophistication
required
• Methods standardization and accuracy: when is a
method ready for use?
The Subcommittee could also raise additional issues that
it deemed appropriate.
B. Application of Research Program Results to Regulation
Development
The primary purpose of the various research programs
within the Office of Research and Development is to generate
technical data and support for EPA regulatory and other
activities carried out under its authorising statutes. The
primary clients for the water quality based approach research
program include the Office of Water and the Office of Federal
Activities. Program priorities are established by ORD
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working through a decision making mechanism called research
committees which are co-chaired by ORD and regulatory office
representatives. Five such committees exist to plan all of
EPA's research, and the work of this particular research
program is planned by the Water Research Committee.
The major regulatory activities the water quality based
research program is designed to support in current and future
years include the following:
1. Single chemical numerical water quality criteria
will continue to be the starting point in developing water
quality based approach NPDES permit limits, and for
evaluating treatment effectiveness under the technology based
approach permits.
2. Approximately five additional water quality criteria
documents per year will be issued over the next five years
for the accelerated control of toxics in NPDES permits, land
banning for SCRA and site investigation for Superfund,
3* Where data are lacking to develop a criteria, water
quality advisories will be issued, about sixty per year for
the next five years, to aid in screening NPDES permits, in
controlling toxics in the water quality based approach.
4. A greater use of biomonitoring or whole effluent
toxicity testing will be made in the next five years to
determine if wastewater effluents are toxic and to establish
NPDES toxicity permit limits in conjunction with, single-
chemical criteria in the water quality based approach.
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5. Biomonitoring or whole effluent toxieity testing
will be incorporated in toxicity identification, toxic
reduction evaluation (TRE's) and pretreatment prograns to
control toxics in response to the Domestic Sewage study and
National Municipal policy.
6, In the longer term, NPDES permits will need to
address mixtures of pollutants from single discharges as well
as those resulting from multiple discharges.
7. To aid in reviewing and issuing the next round of
NPDES permits, a greater use will be made of user-friendly
mathematical models, wasteload allocation software, and
especially expert systems.
8. The need for and value of the control of diffuse and
nonpoint source pollutants will be based on improvement in
water quality using water quality criteria for known
compounds and ambient toxicity testing for unknown compounds.
9, The ability to easily characterize wastewater
effluents, chemically and/or biologically, will continue to
be vital to the technological and water quality based
approaches.
C. Historical Development of water Quality criteria
Since 'the passage of the 1972 Clean Water Act
toendiaents, the development of water quality criteria for the
purpose of setting water quality standards has undergone a
steady evolution resulting in more sophisticated approaches
that have become increasingly equitable to both user and
environment.
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In 1971 the Environmental Protection Agency requested
the National Academy of Sciences (HAS) to revise the ises
Report of the National Technical Advisory Committee (NTAC) to
the Secretary of interior entitled "Water Quality criteria."
The guidelines used by the Academy were similar to those used
by the NTAC, and were based upon the 1965 ammendments to the
1948 Water Quality Act. This Act authorized the states and
the Federal government to set standards for interstate and
coastal waters, considering the uses for such waters,
The NAS document produced (NAS, 1972) thoroughly
utilized the information available at that tine. An effort
was made to define toxic levels at both the acute and chronic
levels for several categories of water use including
recreation and aesthetics, public water supplies, freshwater
aquatic life and wildlife, saltwater aquatic life and
wildlife, and agricultural and industrial uses. Though these
criteria proved useful in guiding both state and Federal
authorities, it was not until the Congress passed the 1972
amendments that the Environmental Protection Agency (IPA) was
charged with, the responsibility for establishing water
quality criteria. The Agency responded with the publication
in 1976 of "Quality Criteria for Water" (EPA 1976) which
derived acute and chronic toxicant levels using conservative
safety factors.
On May 18, 1978 and again on March 15, 1979 the
Environmental Protection Agency published in the Federal
Register guidelines for the formulation of water quality
criteria. These guidelines improved over previously published
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guidelines in that they considered the quality of the
published data used in generating the criteria. Also
considered were environmental differences, and other
biological and physical factors which may have an effect on a
criterion. Both acute and chronic levels were promulgated by
using the methodology. In reviewing the guidelines, the
Science Advisory Board commented on the magnitude of the
variation encountered in the data leading to the formulation
of a criterion level and suggested means to reduce this
variation (EPA 1980).
In 1982, the Environmental Protection Agency prepared a
draft Water Quality Standards Handbook (EPA 19S4a) which
introduced site specific considerations into the guidelines.
EPA also included the concept of ecosystem protection which
was directed toward structural elements of the ecosystem
(protection of a specified number of families within any
affected site).
These changes in the guidelines resulted significantly
from research on an ever increasing data base.by EPA
scientists. The level of thinking (i.e., hypothesis
generation and subsequent research activity) directed the
evolution of criteria formulation.
At the present time, this hypothesis generation/testing
process has moved the Agency into a water quality based
criteria formulation methodology in which such previous
imponderables as duration and frequency of exposure are
considered with implications directed to control technology.
Though this approach is subject to some criticism (EPA l9S4b)
it represents a major scientific advance in criteria
formulation,
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The future research agenda includes the area of whole
effluent effects which revolves around the concept that
organisms and ecosystems are not stressed by individual
toxicants but by interactions of complex mixtures.
Methodologies for the testing of whole effluent effects are
being developed by 1PA scientists and others.
The Subcommittee commends EPA, mud particularly the
water quality criteria research group of the Office of
Research and Development and the Criteria and Standards
Division within the Office of Water, for seeking ever
increasingly relevant and refined methodologies for criteria
formulation.
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II. CONCLUSIONS AND RECOMMENDATIONS
The Subcommittee reached the following conclusions and
recommendations in its review of the research program:
* National Water Quality criteria development is an
important function of IPA'a research laboratories. The
Subcommittee recommends that the EPA continue its program of
developing criteria and periodically reviewing and updating
the criteria development guidelines.
» The methods for deriving water quality criteria have
gone through a steady evolution and extensive reviews. These
methods and the resulting criteria have wide acceptance by
the scientific and regulatory communities.
* The whole effluent and ambient toxieity methods
developed in support of the water quality based approach to
toxics control appear to be major advances in water quality
management. However, demonstration that the removal of
effluent or other source(s) of toxicity to these surrogate
species results in demonstrable positive ecosystem response
should be an important goal for the Agency. Additionally,
efforts to develop methods to assess toxicity persistence in
receiving waters, sediment toxicity, or bioaccumulation,
teratogenic, mutagenic, or carcinogenic potential should be
expanded and be interfaced with single chemical fate and
effects data.
* The recent addition of duration/frequency of exposure in
the water quality criteria framework is to be commended,
* From a scientific perspective, spills, and resulting
exceedences greatly above criteria concentrations, represent
•the greatest remaining weakness in the current intensity-
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duration-frequency regulatory framework; thus, in spite of
the statutory and practical limitation for regulating spills,
the EPA research program should stress them.
• The Agency needs to evaluate the scientific basis and
efficacy of the one-hour averaging period for the criterion
Maximum Concentration (CMC) and the four-day averaging
period for the Criterion Continuous Concentration (CCC).
* The one-hour and four-day durations (averaging periods)
for the CMC and CCC, respectively, present a practical
problem for state agencies that must monitor effluents and
receiving streams for compliance. The Subcommittee
recommends that EPA develop appropriate guidance for states.
* Quantitative data on the relationships between frequency
of exceedence of a criterion (CMC and CCC) and ecosystem
damage and subsequent rates of recovery are lacking. The
Agency needs to conduct research to establish a scientific
base to establish the frequency component of national water
quality criteria. The three-year frequency of excursions
of the CMC and CCC now allowed by the EPA appear to be based
on stresses caused by more catastrophic events than
excursions of the CMC or CCC are likely to cause. The
Subcommittee recommends a thorough review of the recovery
literature and a reassessment of the frequency issue.
* The Subcommittee supports the use of field validation
studies to investigate the reliability of currently
recommended "short-chronic11 effluent toxicity test procedures
for predicting adverse ecological effects in receiving
streams* In addition, research should be conducted to
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develop standardized field methods for performing validation
studies on water quality criteria for specific chemicals,
* The ecoregion methods of defining regional patterns in
water chemistry and aquatic biota can be a valuable tool to
help states define attainable goals in water quality and
aquatic community improvement. The Subcommittee recommends
the EPA continue to inform states of the ecoregion concept
and assess ways in which the concept can be used in state
regulatory programs,
* In the further development and application of the
ecoregion/use-attainability program, the EPA should very
carefully evaluate: 1) the scale of the ecoregion mapping
effort; 2) alternatives for the biological measurements? 3)
special applications for nonpoint source pollution; 4)
special applications for retrospective analysis of water
quality improvement/degradation? 5) user needs? and 6)user
education.
* Pollution from nonpoint sources is a significant road
block to attaining the national goal of fishable-swimmable
waters in many parts of the country. The Subcommittee
recommends that EPA research laboratories expand their
efforts to define and characterize nonpoint source pollution
leading to the more effective implementation of control
measures.
* The Subcommittee does not support the development of
Aquatic Life Advisories unless a minimum data base is
established, a scientifically sound method is developed to
derive the advisory concentration(s) and the method undergoes
review by the scientific community. The Subcommittee
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recommends that EPA consider an aquatic hazard assessment
approach which relates environmental exposure to effects as
an alternative to the present advisories approach,
* The selection of chemicals to develop criteria and
advisories is an important activity. The Subcommittee
recommends that the Agency develop selection criteria. It is
suggested that hazard evaluation approaches be used which
relate estimates of exposure to toxic effects. Utilization
of environmental fate models and quantitative
structure/activity relationships is recommended.
* The Agency needs to develop guidance materials including
manuals and computer based expert systems to aid state agency
and industrial personnel in exposure assessment and wasteload
allocation.
* Research is needed to develop methods to assess the
impacts of toxic chemicals on the structure and function of
aquatic ecosystems.
* Research on the basic biology (e.g., physiology,
pathology, nutrition and ecology) of test organisms is
needed.
* The Agency should continue to develop and publish
laboratory and field methods for assessing the effects of
toxic chemicals*
* A critical need exists for a proactive technology
transfer program to assist state agencies and industry in
implementing the water quality based approach for toxics
control.
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* The Agency needs to coordinate this research program
with,efforts to develop sediment criteria for toxic
chemicals.
• The Subcommittee recommends that EPA explore the
inclusion of research on the potential environmental impacts
of biotechnology as part of its endeavors in support of water
quality based toxics control.
* The Subcommittee recommends that the Agency incorporate
research on marine and estuarine ecosystems into its
activities in support of this research program. A parallel
effort to that underway for freshwater ecosystems is needed.
» EPA should develop a water quality monitoring program to
assess the efficacy of the water quality based approach for
toxics control to improve water quality limited aquatic
systems.
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III. WHOLE EFFLUENT APPROACH
. ,The transition from the technology based approach to the
water quality based approach is fundamental to EPA's policy
for the development of water quality based permit limits for
toxic pollutants. The development of the Cerigdaphnia dubia
ani^ Piaephal^g promelas seven-day effluent and ambient
toxicity tests represent significant milestones in the
implementation of this policy. The Subcommittee commends EPA
for the progress made in this area and encourages continued
support as the methodologies are refined and expanded and
experience is gained on interpretation of results*
The use of effluent and ambient toxieity tests to
evalutate potential impacts is not without precedent.
However, the use of the Cjsr_iodap_hnia, dub^a and PiTnephaj.es
proiae 1 as tests as proposed in the Technical Support Document
for Water Quality Based Toxics Control (IPA 1985) is a
relatively recent development and changes in methodologies,
interpretation, and direction should be anticipated. The
implementation of these methods does not, nor was it
intended, to address all aspects of toxics in the aquatic
environment, nor have all the questions directly addressed by
these methods been resolved. EPA should pay particular
attention to such issues as bioaccumulation, persistence,
sediments, multiple discharges, and teratogenic, mutagenic,
and carcinogenic potential for initiation and/or promotion.
Bioaccumulttion, or the potential for bioaccumulation of
industrial chemical constituents from effluent mixtures, is
not addressed by current effluent or ambient toxicity test
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methodologies. Bi©accumulation, in the case of single
discharges where manufacturing processes can be identified or
where scans for priority pollutants might demonstrate
presence of bioaccumulated chemicals, may be regulated by
monitoring body burdens of resident organisms or through
water quality criteria, where appropriate. However, EPA
should direct some effort toward this process within the
framework of complex effluents with unKnown constituents.
What is needed is a kind of generic n-oetanol/water
partition coefficient perhaps to be found in a HPLC approach.
Persistence is addressed, in part, by ambient toxicity
measurements when tests are conducted on site. Few data
appear to be available regarding correlations between on site
ambient toxicity measures and samples shipped to a laboratory
for evaluation. It remains to be seen if predicitive methods
currently under development will contribute significantly to
the current understanding of persistence.
If one defines as an objective of the water guality based
approach the maintenance of structure and function of aguatic
environments, the problem of regulating multiple discharges
may need to be focused. In the case of multiple discharges,
EPA should emphasize measurement of the system (ambient
toxicity) and not the effluent. Only after the fractionation
schemes currently under development become available for
widespread use is it likely that both satisfactory regulatory
and measurement tools will become available to fully evaluate
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and manage multiple discharges.
'The species currently used in effluent toxicity
evaluations by EPA, an
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Subcommittee believes this demonstration represents an
important undertaking for EPA and one for which particular
attention should be paid to ecologically significant
inprovements, rather than improvements which represent merely
statistical significance*
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IV. NATIONAL WATER QUALITY CRITERIA GUIDELINES/ADVISORIES
A. Background
EPA published revised National Water Quality Criteria
Guidelines in 1985, In this section, the Subcommittee
addresses some specific issues that comprise an integral part
of the three-part water quality criteria by following the
procedures advanced in the 1985 Guidelines document. The
Subcommittee supports the continued development and updating
of aquatic life criteria and encourages the Agency to
continue research and development activities in this area. In
addition, an assessment of the development of "Advisories" by
the agency is discussed in the sections of this report which
follow,
B. Overview of 1985 Guidelines Approach to Establishing
Water Quality Criteria
Briefly, acute toxicity data are collected on
ecologically or cominercially important organisms. Genus Mean
Acute Values (GMAVs) are computed by talcing the geometric
mean of the LCSOs or ECSOs reported for members of the sane
genus. The GMAVs generally conform to a log triangular
distribution, and estimation methods are applied to derive
the Final Acute Value (FAV) as the fifth percentile of this
distribution, since the FAV is calculated from point toxicity
estimates that cause an adverse effect in the test population
(i.e., 50% mortality), the Criterion Maximum Concentration
(CMC) is calculated as the FAV divided by two, and provides a
"safe" level to 95% of the species tested. This
concentration, on the average if not exceeded over a one hour
period more than once every three years, is intended to
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protect the receiving water from acutely toxic effects.
She assessment of chronic toxicity data for aquatic
animals and plants, as well as information on
bioconcentration of chemicals in aquatic organisms, yields a
Final Chronic, Final Plant and Final Residue Value,
respectively. The Final Residue Value is included to prevent
aquatic organisms from obtaining body burdens that are
believed to pose significant risk to huaan and wildlife
consumers. The lowest of the above three values is
designated as the criterion Continuous Concentration (CCC),
which provides an estimate of the highest four day average
concentration that, if not violated with a frequency greater
than once every three years, is advanced as being protective
of aquatic organisms and their uses from being unacceptably
affected by chronic exposure. In the development of a
criterion, additional data regarding the effects on community
structure and/or functional processes (e.g., respiration,
productivity, nutrient cycling) or behavioral responses
(e.g., preference and avoidance, swimming endurance, cough
response) are also reviewed and professional judgment is
used to evaluate the reasonableness of the two-number
criteria, fresh and saltwater, derived via the formal
procedure.
One of the most important features of stating criteria
in accordance with the revised 1985 guidelines is that
criteria are stated in terms of three properties: 1)
concentration (intensity); 2) duration; and 3) frequency.
Specifying criteria in such terms facilitates application of
dynamic statistical models for determining water quality-
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limited situations, rather than using the conservative and,
hence, less cost-effective steady-state model based on 7Qio
flow or the worst-case scenario (Jaworski and Mount, 1985).
c. Intensity (Exposure concentration)
"Intensity11 is defined by EPA in the Technical Support
Document (EPA, 198Sa) as "how nuch of a pollutant (or
pollutant parameter such as toseicity), expressed as a
concentration, is allowable.w The "Intensity" values for
single chemicals or whole-effluent toxicity are specified in
terms of the CMC for protection against acute effects
and the CCC for protection against chronic effects.
The methods for deriving these criteria values have gone
through a steady evolution and extensive review, as discussed
in the above sections. And although the resultant criteria
(intensity) values have been a matter of disagreement for
several individual chemicals (e,g.f selenium) or because of a
perception that national criteria are overly conservative,
the criteria and their methods of derivation have been widely
accepted by the scientific and regulatory communities. Use
of the steadily improved criteria values in the NPDES
permitting process has no doubt been responsible for much of
the considerable improvement in surface water quality in the
past decade. Moreover, the recent incorporation of a
mechanism for reasonably incorporating duration and frequency
of exposure in the regulatory framework (see sections IV.D and
IV.E below) will undoubtedly result in additional
improvements in surface water quality. However, once the
nation begins to achieve the water quality improvements
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possible through the addition of duration/fre
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Unfortunately, spills are not regulated discharges under
NPDES permit limits. From a purely scientific perspective,
however, "spills and resulting exceedences greatly above the
CMC, lio doubt represent the greatest remaining weakness in
the consideration of "intensity of exposure" in the currant
intensity-duration-frequency regulatory framework.
In view of the apparently critical importance of spills
in defining biological integrity, and because of the problem
that this causes for the scientific basis of "intensity of
exposure" in the current regulatory strategy, the EPA
research program should siore aggressively address spills.
Even within the current statutory and practical limitations
for regulating spills, a better scientific understanding of
the frequency of spills in different types of water bodies,
resulting magnitudes of excursion, and the extent of
resultant ecosystem damage can, at least, help define the
nature of the problem. If data show that spills are now a major
contributor to significant water quality degradation,
alterations in the Clean Water Act and EPA regulations might
be necessary, A research program to consider the prevalence
of spills, resultant effects on national water quality, and
possible solutions might include the following:
1. Studies of spill intensity, frequency and duration
in typical surface waters and for different
industrial sectors. Such studies could use
existing data from self-monitoring reports and fish
kill records, as well as collection of new
information using ambient toxicity tests and field
studies,
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2. Studies in the laboratory and field (model
ecosystems?) on the relationships of levels of
exceedenee over the CMC (e.g., 2X, 20X, 200X CMC)
causing ecosystem destruction for different classes
of chemicals. These kinds of studies could be done
in conjunction with the current research efforts on
time requirements for ecosystem recovery.
3. Engineering studies on designs and operating
practices to minimize occurrence or to effectively
contain or dilute spills in different industrial
sectors.
4. Studies of ecosystem parameters that are impacted
by spills, for example the ratio of autochthanous
and allochthanous activity, energy state of
ecosystem (level of system eutrophy),
D. Duration (Averaging Periods)
As advanced in the 1985 Guidelines, EPA specifies a one
hour averaging period for the Criterion Maximum
Concentrations and a four day averaging period for the
Criterion Continuous Concentration. The CMC portion of a
National Water Quality Criterion represents the average
concentration in over one hour which, if not exceeded aors
frequently than once every three years, will protect from
acute toxicity 95% of the aquatic organisms in the receiving
system. The CCC comprises the four-day average concentration
which, if not exceeded more frequently than once every three
years, will protect from chronic toxicity 95% of aquatic life
in the recovery system 95% of the time.
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Acute and chronic toxic effects are a function of both
intensity (concentration) and duration (time). In developing
the CMC, results of 48-hour to 96-hour LC50 or EC50 toxicity
tests that have a constant exposure concentration are used.
Many chemicals express their toxicity rapidly while some act
more slowly. In establishing a one hour averaging period for
the CMC, EPA has taKen a conservative position that protects
against fast acting chemicals. The effects on ecosystem
integrity of an exceedance of the CMC for a duration
(averaging period) in excess of one hour will depend on the
magnitude of the excursion above the CMC and length of
excursion. The effects will be chemical-specific depending
on the rates and modes of action and, thus, the rates at
which effects are expressed. Another factor influencing
whether or not an effect is observed results from whether or
not the exposure is constant or fluctuating. Field studies
conducted by EPA and others have shown that concentrations of
chemicals in receiving systems are usually continuously
fluctuating and not constant (Mount et aju, 1986). Thus,
several factors influence the magnitude-duration interaction
to cause an effect. Scientific data on the ecosystem effects
of exceeding the one-hour averaging period of the CMC by
different magnitudes (and, similarly, data on the ecosystem
effects of exceeding the four-day averaging period of the ccc
by different magnitudes) for different chemicals are not
available to validate the degree of protection provided by
these averaging periods.
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The Subcommittee concludes that the Agency needs to
conduct a literature review to ascertain what is known about
the duration and node of exposure (i.e., continuous versus
fluctuating) for chemicals having different rates and modes
of action. EPA should use the results of this literature
review to evaluate the efficacy of the one-hour averaging
period for the CMC and the four-day averaging period for the
CCC. The results could also be used to identify research
needs to develop the scientific knowledge necessary to relate
averaging period to rates and modes of action. Rather than
having the sane averaging periods for the CMC and CCC for all
chemicals, it should be possible to have different averaging
modes of action. The use of m one-hour duration for the CMC
and a four-day duration for the CCC poses practical problems
for regulatory agencies that must monitor (or require the
monitoring of) effluents and receiving streams for
compliance. The Agency should examine the duration aspects
of criteria from both the scientific perspective and the
practicality of implementation.
E. Frequency
Both the CMC and the CCC in the 1985 Guidelines have an
allowed excursion frequency of once every three years. From
a scientific viewpoint, it is extremely important that the
allowed frequency utilized in water quality criteria be
derived from a strong scientific data base regarding the
ability of aquatic ecosystems to withstand acute and chronic
stress and still maintain their structural and functional
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integrity. The Agency, in developing the Technical Support
Document (TSO) for Mater Quality Based Toxics Control,
reviewed the available scientific literature and concluded
that most unstressed biological communities would not be
"sufficiently" affected if, on the average, one exceedance
event occurred every three years. The TSD acknowledges that
the frequency with which a criterion can be allowed to be
exceeded depends on the structure and function of the aquatic
community, on the spatial relationships to other non-affected
areas, on the presence or absence of other stresses, on the
size of the impacted area, on the type and size of the
ecosystem, on the interval between exceedanees, on the time
of year of the exceedance and a host of other factors. Thus,
the exceedance frequency could be site specific, just as the
CMC and CCC can be site specific.
It is evident that quantitative data on the relative
contributions of the above factors to the rates of ecosystem
recovery are currently lacking and that a carefully developed
research program is needed to establish a scientific base
upon which to establish the frequency component of both
national water quality criteria and the waste load allocation
of the water quality based approach for toxics control.
From the discussions presented at the Duluth meeting,
the Subcommittee believes that EPA is aware of the limited
nature of scientific knowledge related to the frequency with
which different ecosystems can be stressed and still maintain
their integrity.
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The initiation of- a literature review to identify
factors controlling the recovery of aquatic systems from
disturbances (Niemi project) represents a start. The results
of this effort should augment the information assembled in
the Technical Support Document for Water Quality Based Toxics
Control. EPA should use this study to assess the scientific
knowledge regarding the recovery of ecosystems from stresses.
It should also serve to identify research needs on the topic
and to further focus EPA's efforts.
From both the Technical Support Document and the
Subcommittee's experience, it is evident that most knowledge
regarding rates of recovery stems from studies following
major spills of chemicals (i.e., major stresses on
ecosystems). Comparison of an exceedance of a CMC and/or a
CCC in a National Water Quality Criterion to the stresses
produced by a spill and its impact on the rate of recovery of
ecosystems appears to be tenuous. EPA needs to
experimentally determine the relationship between the degree
of exceedance of the CMC and CCC, and structural and
functional responses of ecosystems as well as the
relationship between the frequency of exceedances and
structural and functional responses of ecosystems, and rates
of subsequent recovery. Scientific data do not appear to
exist to judge the appropriateness of an allowed frequency of
once in three years for exceedances of the CMC and CCC. EPA
should use caution in applying the results of studies of
recovery of ecosystems following spills of chemicals to
establish the frequency for National Water Quality Criteria,
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fhe ecosystem stress caused by an exceedance of the CMC or
CCC more than once in three years is probably far less
catastrophic than a spill of toxic chemicals in which the
concentration of chemical may be exceedingly high (much
greater than a factor of two above the CMCi see Section IV,e,
above) and cause lethality to all or most organisms, in
contrast, an exceedance of a CMC and/or CCC of 10-20% several
times a year may not be measurable in terms of ecosystem
impact due to the inability to assess structural and
functional ecosystem responses with great accuracy, EPA
needs to initiate research efforts to address these issues.
F. Aquatic Life Advisories
Overall, the Subcommittee reacts negatively to the
development of water quality criteria advisories because it
believes that the issuance of any number as guidance based
upon a compilation of disparate data represents a step
backwards to the pre-197S approach, and completely ignores
the technical progress made in establishing a method to
derive water quality criteria and a state-of-the-art approach
to environmental safety assessment.
The Subcommittee does not recommend the use of the
advisory concept unless EPA: 1) establishes a minimum data
base? 2} develops a scientifically sound method to derive the
advisory concentration,* and 3) provides a procedure for
appropriate review by the scientific community combined with
ample opportunity for public comment*
The Subcommittee is concerned that users of advisories
would view any concentration values given therein as criteria
which could be translated into standards. If data used to
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develop advisories are insufficient, there might exist a
great potential for misuse. The inability of EPA to issue
aquatic life water quality criteria at the pace that some
people would like must not be the driving force to
inappropriate guidance that will result in scientifically
unsupportable regulations at the state level. EPA, the
states and the scientific community have made too much
progress in the past decade to adopt a quick fix that will
create as many or more problems as it is supposed to resolve.
The Subcommittee believes that, within the current Toxic
Substances Control Act's preraanufacturing notification (PMN)
process and the NPDES regulatory programs, there exists a
scientifically sound alternative to derive "advisory
concentrations." The conceptual basis of the alternate
approach lies within the framework of the aquatic hazard
assessment process for which there is adequate documentation
(Cairns et al., 1978; Dickson et al., 1979? Bergman et al.,
1986? Kimerle, 1986 Gilford, 1985; EPA, 1985a), The
concepts which are applicable are as follows:
o The ,-hazard assessment process utilizes some estimate
of .exposure and the toxicologica1ly safe
concentration to derive the margin of safety. The
decision or assessment is always based on the margin
of safety, the difference between the exposure and
effect concentrations. The current EPA water
quality approach requires that a margin of safety of
at least one be maintained to protect aquatic life.
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o Less than the complete amltispecies acute and
chronic data base now required for deriving water
quality criteria can be successfully used by
employing the concept of uncertainty (Gilford,
1985? EPA, 1985a). Uncertainty factors of one to
one thousand are used, depending on the extent of
s
the toxicological data base, to arrive at an
estimate of the concentration that will be safe for
aquatic life.
o Data are collected in tiers with an initial minimum
acute toxicity and exposure data base. The trigger
for requiring additional data beyond the miniaum is
the margin of safety.
Some members of the Subcommittee were supportive of the
development of Advisories for the practical reason that
advisories can serve a very useful purpose for state agencies
who need information regarding the potential hazards of toxic
chemicals. A real need exists in state regulatory agencies
for "guidance" on chemicals lacking enough data to establish
criteria.
G. Selection of Chemicals to Develop criteria and
Advisories
The Subcommittee believes that the overall water quality
approach to manage the discharge of toxic chemicals in toxic
amounts is technically and strategically sound. However,
since the development of the comprehensive method to derive
chemical-specific water quality criteria in 1980 and the
revisions up to 19S5, EPA has completed and issued very few
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two-number aquatic life water criteria documents from the
original priority pollutant list of 129 chemicals. An issue
that needs to be addressed, in light of the fact of limited
resources, is how to identify chemicals needing the
development of full aquatic life water quality criteria.
Although the list of 129 chemicals has some chemicals that
are of national importance and deserve a national water
quality criterion, many of the chemicals on the somewhat
arbitrarily chosen list of 129 probably should receive a
lower priority than many chemicals not currently on the list,
The Subcommittee concludes that it would be worthwhile
to develop a procedure to identify and set priorities for
chemicals that need a water quality criterion. Further, it
suggests that the basis of that procedure might utilize some
of the newer concepts of hazard evaluation and approaches to
estimate exposure and toxic effects. Chemicals that
demonstrate a large margin of safety between an estimated or
measured exposure and an estimated or measured toxicity data
base could receive a lower priority for consuming limited
resources than a chemical with an obviously smaller margin of
safety. Many new techniques are now available to use
physical/chemical property data to "model" exposure
concentrations in air, water and soils. Models are also
available to predict transformation processes like
hydrolysis, photolysis, adsorption, partitioning, and
degradation which alter the concentrations of chemicals in
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the various environmental compartments. A direct approach to
determine if exposure is of national concern is to measure
exposure concentrations in water, sediments, and fish. To
estimate toxieity the use of quantitative structure/activity
relationships and existing published acute toxicity data
could provide a valuable starting point. Actual acute
toxieity and short term "chronic11 tests could be performed
with a minimum number of species.
The EPA staff in both QRD and the Office of Water should
examine the TSCA-PMN process and NPDES Technical Support
Documents for guidance on how to deal with the uncertainty of
less than complete data bases and to make expeditious
decisions,
As factors for selecting chemicals for which criteria or
advisories are to be developed, the Agency should include
chemicals commonly encountered by state agencies in receiving
waters, landfill leachates, petroleum product spills and
hazardous waste sites.
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V. VALIDATION RESEARCH
• ©ne type of validation study presented to the
Subcommittee involved investigations of the use of effluent
and ambient stream toxieity tests for predicting effects on
aquatic systems that receive toxic discharges. A principal
objective of these investigations, conducted at eight field
sites, was to evaluate the relationship between toxicity
results observed in Ceriodaphnia reproduction tests and
fathead minnow larval growth tests with ecological survey
data collected in the receiving waters. While the
Subcommittee was cognizant of the labor-intensive efforts
(costs) required by such investigations, it strongly supports
the appropriateness of this approach for validating the
currently recommended effluent toxicity test procedures for
predicting adverse ecological effects. It recognizes that
the inherent properties and complexities of natural
(ecological) systems make it difficult to obtain definitive
correlations between toxicity test data and biological
effects that may ultimately result in the aquatic
environment. For this reason, the Subcommittee suggests that
EPA continue these or similar types of validation studies,
but that other ecological parameters in addition to "species
richness" be used and evaluated in the validation process.
Another area of validation effort addressed by the
Subcommittee involved the field studies performed at the
Monticello Ecological Research Station (MERE) to evaluate the
utility of water quality criteria established for specific
chemicals (i.e., PCP, ammonia, chlorine). The Subcommittee
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believes that it is desirable for EPA to continue this type
of research, for it appears to be a logical approach for
validating numerical values derived for national criteria.
However, due to high variability in the other ecosystem
parameters monitored during the validation experiments, data
showing the degree of protection to other structural and/or
functional components are limited. As with the validation
investigations described for complex effluents, it should be
noted that environmental variables encountered in site-
specific studies confound the determination of precise
correlations between field data and laboratory test results.
Therefore, an area of future research worthy of consideration
involves the development of standardized field methods for
performing validation studies. Research should also be
conducted using the MERS to further evaluate the degree of
protection afforded by national water quality criteria to
ecosystew components other than fish.
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VI. USE ATTAINABILITY AMD ECOREGIONS
The fact that water quality characteristics and aquatic
communities vary regionally with climate, surface geology,
soils, vegetation and land use patterns is not a new concept.
The ecoregion napping program developed by the staff at the
Environmental Research Laboratory - Corvallis presents a
consistent and defensible representation of these patterns
nationwide. Tests of ecoregion delineations in at least two
states, Arkansas and Ohio, have demonstrated similar water
chemistry and stream communities within an ecoregion and
differences in these characteristics between ecoregions.
Since water quality varies naturally from place to
place, it is not only appropriate but imperative that Federal
and State regulatory agencies consider this fact in their
efforts to achieve the national goal of fishable-swimmable
water "wherever attainable." When setting water quality
standards and effluent limitations, states must be aware of
the local water quality background and the aquatic community
being protected. The ecoregion approach is a tool that can
help states and EPA regional offices define regional goals
for attainable water quality and aquatic biota. This tool is
especially useful in defining the water quality and aquatic
commmsity attainable in a given region. Thus, regulatory
officials and scientists can establish reasonable goals for
expected improvements following pollution abatement efforts.
Ecoregions will not, however, replace the need for wasteload
allocations and site-specific toxieity studies necessary to
establish effluent limitations for individual dischargers,
although they will facilitate nodal ing for wasteload alloca-
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tion within each region.
In Minnesota, as one example, the ecoregion approach is
being used for two primary purposes as follows: l) to assist
the Minnesota Pollution Control Agency (MPCA) focus and
prioritize its nonpoint source pollution control programs;
and 2) to aid in the analysis of statewide water quality
data. In the first instance, the MPCA has assessed
characteristics within Minnesota's eight ecoregions that are
pertinent to the evaluation of nonpoint sources and to the
application of best management practices for nonpoint. source
pollution control. Many of Minnesota's lakes are impacted by
nonpoint source pollution. To help address this problem, the
MPCA is working on a total phosphorus water quality standard
for lakes using the ecoregion concept. Assessing lakes by
ecoregion helps define the trophic status that can be
achieved in a given lake. The MPCA has identified regional
patterns in several lake characteristics that can affect
trophic status such as morphometry and stratification
patterns, as well as nutrient concentrations. Under the
second example, the MPCA has analyzed its ambient water
quality data by ecoregions for the biennial report of water
quality to Congress (3Q5b Report).
The Subcommittee recognizes the absolute necessity for
improved strategies of use attainability analyses as well as
the potential value of the ecoregion concept as a regional
tool to help agencies define patterns in water chemistry and
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aquatic biota, which are in turn helpful in defining use
attainability.
The Subcommittee has several concerns about both the
development and the application of the ecoregion mapping
concept and use-attainability analysis method. in the
further development and application of the ecoregion/use-
attainability framework, the Agency should very carefully
evaluate: 1) the scale of the ecoregion mapping efforts; 2)
alternatives for the biological measurements; 3} special
applications for nonpoint source pollution; 4) special
applications for retrospective analysis of water quality
improvement/degradation,* 5) user needs; and 6) user
education.
1) Scale. The most reasonably attainable and usable
scale of the ecoregion mapping effort should be carefully
evaluated. The tendency for these kinds of efforts is to
continue to develop finer and finer scales in the analysis
and mapping. This tendency is driven by the correct
perception that a course (national, regional) scale is not
useful for local application of ecoregion maps to use-
attainability questions. But this fact must be balanced with
the actual need (or lacK of need) for fine scale maps at all
localities, as well as the achievability of such maps given
the data limitations that are likely to exist. One option
for the Agency to consider would be the completion of
national and regional maps for analyses at those levels,
accompanied by m guidance document and training programs to
assist state agencies in data collection and mapping at finer
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scales for surface waters where it is appropriate and useful
for use-attainability analyses. This local level analysis
and ecoregion mapping approach may be very useful for
important surface waters to set site-specific water quality
standards, to set effluent limitations for specific
discharges, to establish nonpoint source controls, and to
evaluate progress in attaining water quality improvements.
2) Biological Measurement Alternatives. The biotic
index approach, based on fish community analysis, offers
considerable promise for ecoregion mapping and use
attainability analysis. However, alternative approaches
should continue to be considered by the Agency and used, if
and where appropriate. Two examples of alternative
approaches include fish Habitat Evaluation Procedures (HEP)
and ecosystem function measures. The HEP approach has been
developed extensively by the U,S. Fish and Wildlife Service
and could be very useful for use-attainability analyses and,
thus, local scale ecoregion (habitat) mapping (see Dickson
and Rodgers, 1986). Ecosystem function measurements (e.g.,
primary production or production/respiration) may be very
useful for analysis and management of many nutrient-related
nonpoint source pollution problems. In a previous manual on
water body surveys and assessments, EPA (1984b) reviewed a.
number of biological measurement alternatives for use-
attainability analyses. The Subcommittee recommends
continuation of this practice rather than selecting any
single method for biological assessment of surface waters.
3) No_npoint Source Apjg lie actions. The Subcommittee
agrees that the ecoregion mapping approach would be
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especially useful in nonpoint source evaluations (as
presented in the Minnesota example, above), since this type
of application was not discussed extensively during the
review, the Subcommittee can only recommend that the Agency
carefully consider whether the ecoregion mapping effort
(including preparation of guidance to regional and state
agencies) accounts for the variables that would be most
important for nonpoint source problems (e.g., soil
erodability, prevalent agricultural crops, primary
production),
4) Retrosgective Analysis App_l igations. The Subcommittee
suggests that the ecoregion mapping/use attainability
framework should be applied to the assessment of national and
regional progress in achieving surface water quality
improvements. Although states are required to submit
biennial National Water Quality inventory reports (SQSb
reports) that are reviewed and summarized by EPA, too
little effort appears to be expended by EPA in compiling
these kinds of "progress reports." such progress reports
should be very useful for EPA in allocating resources for
further improvements that are needed and achievable. The
ecoregion concept could be useful for subdividing this
problem if the ecoregion mapping exercises were approached
with such an application in mind (also see Section IX. F).
s) jser Needs. As in any research program where the
products of national-scope research efforts are to be applied
to local-scale problems, it is imperative that the
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researchers maintain frequent contact with regional and local
users to be sure that the intended research product will meet
local" needs. Thus, the Subcommittee encourages the research
team at ERL-Gorvallis to continue solicitation of critical
input from regulators and regulated parties in the field
through presentations at national, regional and local
meetings and workshops. During these exchanges, the
research team should invite critical input on alternatives
(e.g», biotic index, HEP, ecosystem structure and function,
ambient toxicity assessment) as well as special needs
associated with various applications of the ecoregion
mapping/use-attainability framework (e.g., point source,
nonpoint source, ambient toxicity assessment). The Agency
should also continue applications/demonstrations, such as
those in Ohio and Arkansas, prior to settling on the final
form for the ecoregion mapping/use-attainability approach.
6) H§er Education, once fully developed, a carefully
prepared, complete guidance document should be drafted (e.g.,
BPA, !Si4a) and subjected to scientific and user review. The
final draft of this document should then be used as the basis
for regional workshops on the application of ecoregion
mapping/use-attainability in regional and state programs.
The successful effort by EPA on the preparation and
dissemination of the Technical Support Document for Water
Quality Based Toxics Control (EPA, 1985a) should provide an
excellent example for this program.
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VII, WASTELOAD ALLOCATION
Exposure assessment involves predictions of how much,
how long and how frequently a receiving system is subject to
concentrations of chemicals and/or effluents exceeding water
quality criteria. The spatial and temporal extent of aquatic
life exposure to toxicants will vary depending on variations
in the assimilative capacity of the receiving water and
variations in effluent composition and quantity. Regulatory
agencies utilize wasteload allocation (WLA) models in the
water quality based approach for toxics control to predict
exposures and to calculate the effluent quality required to
meet the criteria and protect the beneficial uses of the
receiving water.
The major responsibility within EPA for conducting
exposure assessment research and developing WI*A models
resides with the Environmental Research Laboratory at Athens.
This laboratory currently has six major research activities
to support wasteload allocation and permitting from a single
chemical modeling perspective. They include:
* Environmental and chemistry processes
characterization and research
* Biodegradation and bioaceumulation processes
characterization
• Expert systems to predict chemical/physical
reactivity and transport properties
• Expert systems for environmental management
• I^ad allocation models development and evaluation
* Technology transfer and user assistance
Based on the materials supplied to the Subcommittee and
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on the presentations at Duluth, it appears that the
activities at Athens effectively address the major research
and development needs related to exposure assessment and
wasteload allocations. The development of expert systems to
assist users (i.e., permit writers and environmental decision
makers) is an important area which the Subcommittee
recommends for a high priority in allocation of resources.
For the Agency's water {juality based toxic controls program
to succeed, permit writers must be able to effectively use
environmental fate and load allocation models. These models
are complex and require significant understanding and
experience on the part of the user. Expert systems provide
an effective means of transferring the knowledge and skills
of environmental fate scientists and modelers to the user.
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VIII. METHODS STANDARDIZATION
A. -Field Methods
One of the more difficult endpoints to define is the
effect of a toxicant on ecosystems. Though difficult to
obtain, ecological scientists have tested several measures
that offer some hope of assessing ecosystem effects.
Research is needed, however, to quantify these effects and
identify additional measures.
Ecosystem attributes can be categorized into three
groups: 1) state variables which encompass such structural
attributes as standing biomass, species richness, species
diversity, species importance and trophic level's; 2) process
variables which include such attributes as rates of uptake
from one trophic level to another, and rates of
photosynthesis, respiration, and metabolism; and 3) control
variables which control the rates at which processes proceed.
A keystone species controls the structure of the ecosystem
and in so doing controls the processes.
The Subcommittee encourages the Agency to continue to
develop field methods to assess the impacts of toxic
chemicals on aquatic life.
The reemphasis on measuring and alleviating impacts to
biological systems further demonstrates the need to develop
methods to characterize and measure impacts. It also
focuses, as has EPA's acid deposition program, attention on
the need for long-term monitoring of ecosystems. The value
of documented historical, data bases cannot be overemphasized.
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B. Basic Biology of Test Grgansisms
The role of methods standardization, quality assurance,
and technology transfer in the water quality based approach
to toxics control should not be underestimated. The
development of the Ceriodaphnia dubia seven day toxicity test
should have reinforced the necessity to develop programs to
produce information on the basic biology (e.g., physiology,
pathology, nutrition and ecology) of test organisms, the
methods to culture and test the organisms, and to transfer
the methodology to potential users. It is also important to
continue to seek new species, or modify methods for existing
species, as a means to add to the collection of organisms
satisfactory for use in evaluations of aquatic ecosystems.
c. Publication of Standardized Methods
The research and development activities at the
Environmental Monitoring Support Laboratory at Cincinnati
have provided valuable data germane to the water quality
program. One important contribution has been the development
and publication of standardized methodologies for effluent
biomonitoring. Activities at EMSL Cincinnati that warrant
continued support include additional evaluation and
*.
standardization of short-term effluent toxicity tests with
other saltwater and freshwater organisms; the development of
new and rapid toxicity test methods; the establishment of
additional reference toxicants for determining toxicity test
precision? and the completion of new toxicity testing method
manuals. Because of EPA's increased emphasis on the
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environmental and regulatory importance of sediment-
associated toxicants, the development and standardization of
test methods for evaluating sludges, leachates, sediments,
and hazardous wastes appear to be especially relevant.
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IX, AREAS RELATED TO THE WATER QUALITY BASED APPROACH TO
TOXIC CONTROLS NEEDING ATTENTION
A. "Nonpoint Sources
In many parts of the country, pollution from nonpoint
sources is a more serious problem than pollution from point
sources. Programs to monitor, assess, and control point
source pollution are well established, but many states are
only beginning to develop nonpoint source pollution control
strategies. Most of the research programs at the EPA
research laboratories have been directed toward the control
of point source related problems.
The Subcommittee recognizes the importance of dealing
with the nonpoint source pollution problem if the nation is
to achieve the national goal of fishable-swimmable water
wherever attainable. The Subcommittee also is aware that, in
may respects, the control of nonpoint source pollution
represents a greater challenge than controlling point
sources. The Subcommittee recommends that SPA expand its
research effort in nonpoint source pollution and has
identified the following issues as needing research priority:
* What are the impacts to aquatic communities fron
the runoff of pesticides, herbicides, and other
toxics from nonpoint sources , considering the
intensity, duration, and frequency of exposure?
* What are the loading dynamics of nonpoint source
toxics to streams in a given watershed?
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• What water quality characteristics are the best for
monitoring nonpoint source pollution over the long-
term?
• What are the appropriate water quality criteria for
toxics and conventional pollutants for assessing
nonpoint source pollution?
* Will the implementation of best management
practices in a watershed to protect surface waters
from nonpoint sources have a negative impact on
area ground water?
B. Technology Transfer
The Subcommittee realizes that the water quality based
approach requires a higher degree of technical expertise than
previous efforts. Therefore, a need exists for the EPA to
inform, educate and provide technical assistance to state
regulators and industries to incorporate this approach into
their pollution control programs. Specific assistance is
needed ins 1) calculating water quality criteria following
the EPA prescribed method? 2) incorporating the two number
criteria into usable programs; 3) developing guidance on how
to use the water quality advisory concept; 4) determining
use-attainability? 5) calculating wasteload allocations; 6)
establishing routine use of computer models in wasteload
allocations; 7) identifying sources of toxicityi and 8)
implementing of the Technical Support Document for Water
Quality Based Toxics Control.
Successful attainment of the national goals contained in
the Clean Water Act depend greatly upon implementing this new
technology. Therefore, a commitment needs to be made to
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transfer this technology. Because this activity is so
important, 1PA should consider constituting a dedicated team
of technology transfer experts to prepare and present the
approach in a comprehensive program to the user community.
The format could take the form of guidance manuals,
workshops, and seminars. Representatives from industry and
state regulatory agencies should participate. The program
goal should be the education of all parties concerned,
especially individuals at the state level who would not
ordinarily be given the opportunity to participate because of
financial constraints,
C. Sediments
Based on a review of materials supplied to the
Subcommittee and the presentations at the Duluth meeting, it
is evident that EPA needs to direct more attention toward
coordinating the water quality based approach for toxics
control with efforts to develop sediment criteria for
chemicals. Water and sediments in aquatic ecosystems
interact via abiotic and biotic mechanisms. While often
viewed as separate environmental compartments from an
environmental fate and modeling perspective, it is well
documented that the concentration of chemicals in water
affects the concentration of chemicals in the sediments. The
reverse is also true.
The degree of interaction depends on the chemical, water
quality and physical/chemical characteristics of the
sediments. Since the objective of the water quality based
approach is to establish discharge limits and/or determine
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allowable instream contaminant concentrations, it is
essential to incorporate as part of the approach an
assessment of the potential effects of an effluent on
sediment quality and associated benthic organisms. The
present efforts are totally directed to assessing exposure
and effects in water. An assumption is made that protection
of water column associated organisms will protect benthic
organisms. The scientific basis for this assumption is not
well developed.
The Agency needs to better coordinate and integrate its
efforts between those staff developing sediment criteria for
chemicals and the scientists at the environmental research
laboratories that participated in the development of water
quality criteria. Finally, EPA should consider factoring
into the water quality based approach sediment interactions
with effluents, and the role of sediments in influencing the
fate and effects of chemicals.
If EPA does not factor sediments into the water quality
based approach, it faces a real danger of misjudging an
effluent as having no effect on the aquatic ecosystem based
on water column focused assessment methods. It could
subsequently discover that, because of the nature of the
chemical constituents and the nature of the sediments in the
receiving system, toxicants build up to harmful levels that
adversely impact benthic organisms and organisms associated
with the water sediment interface. The Subcommittee
recommends that EPA explore this issue more seriously.
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D, Biotechnology
The Subcommittee notes that the program contains nothing
related to the important issue of biotechnology and its
environmental impact. With the excellent water quality-
expertise available at the Duluth laboratory it would be
prudent for EPA to have some of its staff involved in
biotechnology environmental impact analyses. The
Subcommittee recommends that EPA consider what role the
Duluth laboratory personnel could play in this important
national issue. Likewise, scientists at the Gulf Breeze ERL
should be involved in the water quality based approach
research activities.
E. Saltwater
During the subcommittee's review, it was very clear that
the Agency has not incorporated marine and estuarine
ecosystems into its research and development efforts. The
reasons for this omission are not clear. However, from a
conceptual perspective the Subcommittee sees no reason why
the water quality based approach should not be applied to
marine and estuarine ecosystems. It is apparent from the
Sixth Draft of Strategic Five Year Plan for Freshwater
Ecological Processes and Effects Research that the Athens,
Corvallis and Duluth laboratories have effectively
incorporated research and development activities related to
the water quality based approach into their future plans.
The Subcommittee cojnnends this effort, but it is essential
to coordinate research efforts on the water quality based
approach with marine and estuarine ecosystems. Methods for
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rapidly assessing the fate and effects of effluents
discharged into saltwater environments applicable to the
water quality based approach, and models to estimate
exposures and wasteload allocations, need to be developed
along with freshwater approaches.
F. Monitoring
It is important to know that any effort once applied is
effective. The attenpts to do this in the water quality
criteria area has been at best superficial. The President's
Council on Environmental Quality has traditionally produced
an annual state of the environment nsessage. During those
administrations when the Council carried a higher priority,
this environmental message was designed to give a general
impression of environmental quality and did not provide
specific analysis to the point where one could gauge the
degree of impact of a specific regulatory action. The
Environmental Protection Agency was also charged in the 1972
Clean Water Act Amendments to produce a biennial National
Water Quality Inventory. This effort relies heavily on the
states to provide the information which is often incomplete.
EPA should test its strategies in water quality criteria
formulation with a monitoring program based on a set of
randomly selected streams in the United states with a view
for following guideline and criteria formulation application
and their effects on water quality.
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X. Literature Cited
Bergman, H.L», R.A. Kimerle, and A.W. Maki, 1986,
En v i ronmenta1 Hazard Assessment of Effluents, Pergamon
Press, New fork, 366 p.
Cairns, John Jr., K.L. Dickson and A.M. Maki, 1978.
Estimating the Hazard of Chemical Substances to Aquatic
Life, STP 657. American Society for Testing and
Materials, Philadelphia, PA 278 p.
Dickson, K.L., A.W. Maki and J. Cairns, Jr*, 1979. Analyzing
the Hazard Evaluation Process, American Fisheries
Society, Washington, D.C. 1S9 p.
Dickson, K.L. and J.H. Rodgers, Jr., 1986. Assessing the
Hazards of Effluents in the Aquatic Environment, in
525[il£!121£S^*A M51^I§ £sjse_ssinent of EfflHES^l* H-L*
Bergman et al«, eds, Pergamon Press, New York, 336 p.
Gilford, J.H, 3.9S5. Environmental Effects Assessment of New
Chemicals ,Under the Toxic Substances Control Act.
Summer National Meeting, American Institute of Chemical
Engineers, Seattle, WA,
Jaworski, N.A. and D.I. Mount, 1985. Use of Statistical
Information to Improve Compatibility Between the Various
Components of the Water Quality-based Approach, in
Aguatic Toxicology and Hazard Assessment, R*D. cardwell,
R. t»urdy and R.C. Bahner, eds. Seventh Symposium, ASTM
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STP 854, American Society for Testing and Materials,
Philadelphia, PA, pp. 565-573.
Kimerle, R,A.f 1986, Has the Water Quality Criteria Concept
Outlived Its Usefulness. Environ. Toxico. and. chem.,
5:113-115,
Mount, D.I., A.E. Steen and T.J. Norberg-King, 1985.
Validation of Effluent and Ambient Toxicity Testing for
Predicting Biological Impact on Five Mile CreeK,
Birmingham, Alabama. EPA/600/8-5/015.
National Academy of Sciences, 1972. Water Quality Criteria.
EPA R3-73-033,
U.S. Environmental Protection Agency, 1976. Qua1ity Criteria
for Water. Washington, D.C.
U.S. Environmental Protection Agency, Science Advisory Board,
1980. Report on Water Quality Criteria for Protection
Of Aquatic Life and Human Health. Washington, D.C,
U.S. Environmental Protection Agency, 1984a. Water Quality
Standards Handbook. Office of Water Regulations and
Standards (WH-585), Washington, D.C.
U.S. Environmental Protection Agency, 19S4b. Report on site
Specific Water Quality Criteria* Washington, D.C.
U.S. Environmental Protection Agency, 19S5a. Technical
Support Document for Water Quality Based Toxics Control.
Office of Water, Washington, D.C.
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U.S. Environmental Protection Agency, Science Advisory Board,
198Sb, Report on Water QMlIltY Criteria. Washington
D.C.
U.S. Environmental Protection Agency, 1985c. Guidelines for
Deriving National Water Quality Criteria. Washington,
D.C.
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