UNITED STATES ENVIRONMENTAL PROTECTION AGENCY*
WASHINGTON. D.C. 20460
October 13, 1983
Mr, William p. luckelshaus
Administrator
401 M Street, SW
Washington, D.C. 20460
Dear Mr. Ruckelshausi
The Science Advisory Board has endorsed the enclosed report of its
Environnental Effects Transport and Pate Committee, entitled "Report on Site
Specific Water Quality Criteria" • The Committee has carried out an indepth
review of this issue , and its major conclusions and recemnendations are discussed
in the enclosed report*
•s
The Science .Mvisory Board strongly encourages the Office of Water Regulations
and Standards to incorporate the reconmendations in the report into its Site
Specific Water Quality Standard Guidelines. We believe that the site specific
guidelines and the acccn^janying mcotmendations offer a new landmark in approaches
to the development of standards to assure the quality of the aquatic envire-nuent.
The Science Mvisory Board wishes to thank the dedicated Agency staff who
provided great assistance' in the preparation of this report* The Board also
urges further consultation and involvement by its Environmental Transport and
Fate Committee in the further development of the guidance. ""'
Sincerely yours,
'
Efolf Harfcung,
Environmental Effects, Transport
and Fate Comittee .
i
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.HEPQRT ON
SITE-SPECIFIC WATER QUALITY CRITERIA
by
The Environmental Effects-, Transport, and Fata Committee
of the
Science Advisory Board
October 13, 1983
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EP4 NOTICE
This report has been written as a part of the activities
of the Agency's Science Advisory Board, a public advisory
group providing extramural scientific information 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. The contents of this
report do not necessarily represent the views and policies
of the Environmental Protection Agency.
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TABLE OF CONTENTS
Committee Roster . * . ....... »,,.«».....»».»,,... , ......... iv
Charge to the Committee ---- ...*....„. ............... .... v
Executive Summary ......*..,.,..,.**. ____ .... ..... .......... 1
Introduction ..,.....„,.».,..,» ....... ,,.«.,............. 4
Major Recommendations ................ ».,,, ........ ...... 5
Problem Statement and Resolution .......... ..... , ...... «. 6
Limitation of Toxicity Testing ,,.»*..,........ ....... 6
Role of Toxicity Data ............I.,.,,,..,..*.,..... 7
Issues Related to foxicity-Based Data ...... .......... 8
Statistical Issues in the Site-Specific
• Water Quality Criteria .,»,,,....,.. ......... .,,»»» 10
Desired Environmental Quality —
Definition of Environmental Integrity ,......,.*... 11
Specification of the Environmental
Protection Problem , ......... ., ............ ........ 12
Choice of Diagnostic Variables ... ............... ..... 13
Environmental Monitoring ............ .......,,,,,.,,.. Ill
Protocols for Environmental Monitoring ..... ......... . 15
Issues ,».«.»........,.....»,....,,...........,,,., • 17
The Purpose of Monitoring .. ...... „ ..... .»,....„. 17
Organisms to Use in a Monitoring Study ..... ,.*.. 20
Frequency of Monitoring ,,.. .................. ,,, 21
Monitoring Feedbacks .... ..... .,..,,,,,..,,..,,... 23
Specific Procedures in the Guidelines
Recalculation Procedure .. .................. ,.,.»...*.• 24
Indicator Species Procedure .. ....... ...... .......... . 25
Resident Species Procedure ........................... 29
Heavy Metal Speciation Procedure . .............. ..,,,, 29
Historical Procedure .».».«.,..*......... ...... ..„,.,,, 31
Final Residue Values ..*.*.......,......**.....,...... 31
Criteria for Site Definition ..... .................... 34
References ..,,...»,**. ................ ..... ...... .-,,,,., 37
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Appendices ,.,..,, *...*....,...,....».,... 40
Appendix 1 ....,.,.. ...,,, 1-1
System Theory Formulation of the Environmental
Protection Problen and Protocols in Relation to
Site-Specific Water Quality Criteria
Appendix 2 '..**.. , *... ,....,,...•*... 2-1
Evaluation of Case Histories in Relation
to Field Verification of Proposed
Guidelines
1X1
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9/83
ENVIRONMENTAL EFFECTS, THANSPQHT AND FATE COMMITTEE
Dr. Rolf 3. Hartimg, Chairman
Professor, Environmental
and Industrial Health
University of Michigan
inn Arbor, Michigan
Dr* Douglas B. Seba
Executive Secretary
United States Environmental
Protection Agency
Science Advisory Board
Washington, D.C*
MEMBERS
Dr. Mlforti R, Gardner
Head, Deparatment of Soils,
Water, and Engineering
University of Arizona
Tucson,, Arizona
Dr. Robert E. Gordon
Professor of Biology and
Vice President for Advanced
Studies
University of Notre Dame
Metre Dame, Indiana
Dr. Charles Hosier
Professor of Meterology
College of Earth & Mineral Sciences
Pennsylvania State University
University Park, Pennsylvania
Dr. Tony Peterle
Department of Zoology
Ohio State University
Columbus, Qfaio
Dr. John Neuhold
Department of Wildlife Sciences
College of Natural Resources
Utah State University
Logan, Utah
CONSULTANTS
Mr, Italo Carcieh
Bureau of Water Research
NTS Dept, of Environmental
Conservation
Albany, New York
Dr. Leonard Greenfield
Consultant
Miami, Florida
Dr * Charles Norwood
Radix Data, Inc.
Consultant
Norchridge, California
Dr, Kenneth DIckson
North Texas Stata University
Institute of Applied Sciences
Denton, Texas
Dr. Kenneth Jenkins
Professor of Biology
California State University
at Long Beach
Long Beach, California
Dr. Bernard Patten
Professor
Department of Zoology
University of Georgia
Athens, Georgia
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CHARGE TO THE COMMITTEE
On November 4, 1982, the Environmental Effects, Transport and
Fate Committee of the Science Advisory Board accepted the
charge to evaluate the scientific validity of the procedures
proposed as guidance for 'the States by the 0. S. Environmental
Protection Agency for the development of site-specific water
quality standards.
Among the issues that the Connittee was requested to address
were the following:
1. Determination of whether or not the site-specific
guidelines mora correctly protect the various uses
of aquatic life by accounting for toxicological
differences in species sensitivity or water quality
at specific sites for designated uses.
2. Evaluation of species sensitivity ranking and
toxicological effects derived from appropriate
laboratory tests.
3. Discussion of the stringency of site-specific
criteria developed from biological data on
aquatic or terrestrial animals vs. the
concentrations of pollutants affecting plants or
concentration/effect data in the category "Other
Data" found in the national criteria documents.
4. Evaluation of procedures to modify criteria to
account for some characteristics of local sites.
Among these procedures are the Recalculation
Procedure, the Indicator Species Procedure, the
Resident Species Procedure, the Heavy Metal
Speciation Procedure, the Historical Procedure,
and the Final Residue Value Procedure,
In the course of its deliberations, the Committee 'was also
requested to evaluate a series of site-specific test studies
which had been conducted according to the draft guidance
procedures.
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EXECUTIVE SUMMARY
la November 1982, the Environmental Effects, Transport and Fate
Committee of the Science Advisory Board was requested by the
Assistant Administrator for Water to review a set of proposed
guidelines by which national water quality criteria could be
adapted to derive local water quality standards, taking site-
specific conditions into account,
The Committee determined that the basic goal, to derive site- »
specific standards, was both important and necessary.. The
application of single national criteria in the form of local
standards to situations as diverse as the Great Lakes, the
lower Mississippi, or a Colorado mountain stream had been
challenged frequently before.
Since the proposed guidelines were often modifications of the
existing methodology for the setting of national water quality
criteria, many aspects involving those methods also Had to be
considered*
The Committee found that many aspects of the proposed guide-
lines did not make adequate use of existing information and
that the logical foundation of some sections of the guide-
lines was flawed.
The site-specific environmental problem, as presented to this
Committee, was poorly specified. As a result, the existing
procedures are inadequate and in need of revision*
While the Clean Water Act specifies that the physical,
chemical, and biological integrity of the environment shall
be protected, the Agency has failed to provide more specific
benchmarks to serve as the basis for designing protective
strategies and against which the performances of various
protective strategies could be judged.
Toe proposed guidelines, as well as the national water quality
criteria, are largely based on laboratory toxicity studies.
Aside from issues related to the statistical validity related
to the desired protection of 95$ of the species or 95$ of the
families, laboratory toxicity tests fail to account for inter-
actions between species, ecosystem level effects, interactions
with other chemicals, and modifications by local water quality
characteristics. The species tested in the laboratory are
assumed to reflect significant or Important species in the
environment.
The Committee concluded that the sum of such assumptions
made it essentially impossible to discern a logical framework
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which would'guarantee achieving the protection of the environ-
mental integrity of aquatic systems. However, the Agency
did recognize the need to account for the effects of local
water quality on the boxicity of pollutants; did make progress
in selecting representative species; and did recognize the
need for field verification as part of the proposed site-
specific guidelines. However, the extent to which the national
criteria, or by implication the proposed site-specific guide-
lines, provide protection appears to be mainly based on their
conservative features, rather than on any defensible scientific
derivation.
While the national criteria and the site-specific modifications
are centered around laboratory toxieity studies, the Committee
strongly recommends that the site-specific standards should be
centered around the responses of ecosystems and their components
in an environmental rather than laboratory setting,
Thus, the Committee places a much greater emphasis than does
EPA on biological, chemical and physical monitoring. The
monitoring must be relevant to the detection of adverse impacts,
and it must view the ecosystem in dynamic terms dedicated to
specific uses.
The proposed guidelines suggested that site specificity could
be achieved through the application of one or more procedures:
1. I "recalculation procedure," which recalculates the
criteria 'by taking account of differences between the
species tested as part of "ihe national data base and
those species which actually occurred or were expected
to occur at a local site. This procedure is basically
an extension of the methods for the derivation of the
national criteria based on laboratory toxicity testing.
While it does represent a logical refinement'of the
national criteria, it is subject to the same short-
comings, with respect to ecosystem applicability, as
the national criteria.
2. An "indicator species procedure," in which acute
bioasgays are conducted in site water and in defined
laboratory water to derive a ratio which represents
the iopact of local water quality. This ratio is
then applied to the national data base. The procedure
assumes that the ratio between acute and chronic
toxicity is constant for a given chemical and that
the influences of water quality on toxicity in short-
term tests at high doses will also hold for long-term
low level exposures. Preliminary studies have
indicated that this water effects ratio may differ
significantly depending upon the species selected,
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especially between fish and Invertebrates, In
addition, such a water effects ratio appears to tie
highly dependent upon the sampling and storage methods
for the local site water,
3» A "resident species procedure," in which the national
toxicity data base is repeated for both acute and
chronic toxicity using local species in site water.
This method still retains many of the shortcomings of
the 'toxicity-based national criteria, except that it
may account for the impact of local water quality better
than the "indicator species procedure1* does.
4. i "heavy metals speciation procedure»" which depends
upon the metal concentration in a 0.45 urn filtrate.
rather than total metal concentration. The Committee
agreed that the chemical and physical forms of heavy
metals in water were important determinants of biological
activity. However, better methods than simple filtration
are available for many forms and_ should be utilised.
5. 1 "final residue value procedure," which is essentially
identical to that in the national water quality criteria
methodology and is based on laboratory data. Such
laboratory data have, in practice, often differed from
field data. The final residue values for site-specifie
conditions should be coupled more closely to actual
field conditions.
As part of its endeavors relating to the site-specific
guidelines, the Agency commissioned several site-specific
evaluations* of the proposed guidelines. In the aggregate,
these studies were judged to'be very inadequate, but they
provided a useful learning experience; they tended to point
out some 'of the frailties of the originally proposed methodology,
a number of which are also cited in this report. Evaluation
of the studies also indicated that their design needs to be
improved and that the Agency needs to develop better technical
guidance for such studies. This report makes a number of
recommendations about how that might be accomplished.
Though the Committee was often critical of various aspects of
the proposed guidelines, such criticisms were offered with
the 'intent to be helpful. Above all,
*' the ^Committee urges the Agency_to_ continue its
development Qf_site~specifio guidelines^and not to
abandon such efforts because of initial criticisms.
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INTRODUCTION
Section 30^(a) of the Clean Water Act specifies that the
Administrator of the Environmental Protection Agency promulgate
criteria, based on the latest scientific knowledge, to protect
both the biological integrity and specified uses of the
Nation's waters, SPA to date has developed national criteria
for a number of pollutants and is currently developing guidance
for site-specifio standards. In this report the scientific
basis of the site-specific standards is examined.
For many reasons, national water quality criteria are often
deficient when applied as standards, without modification, to
local conditions. Thus, developing scientifically defensible
site-specific water quality standards is an extremely important
and necessary taste,
The proposed methodology for the derivation of site-specific
standards is inseparably intertwined with the methodology for
setting national water quality criteria. Therefore, it was
impossible to appropriately consider the site^specific
methodology without also examining many aspects of the
methodology for deriving the national criteria.
The national water quality criteria documents constitute a
valuable collection of background information on the effects
of pollutants on selected species under laboratory conditions.
Unfortunately, the national criteria did not adequately
consider the broad range of interactions between pollutants
and among species at the ecosystem level, which becomes very
important when standards are to be set to appropriately
protect an ecosystem at any given site.
The Environmental Effects, Transport and Fate Committee of
the Science Advisory Board identified a number of important
guidelines and the national water quality criteria from
which those guidelines are, in large part, derived. The
following sections of this report address those problems and
suggest approaches to remedy them.
While the Committee has found serious deficiencies in the
scientific bases for the criteria and the standards, it
strongly urges the Agency to develop those scientific bases
and incorporate them into its methodologies as rapidly as
possible.
In various sections of this report, a series of demonstration
projects, which were conducted to explore site-specific
guidelines, is referred to. There are separate brief critiques
of these in Appendix 2.
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MAJOR RECOMMENDATIONS
I. The role of environmental monitoring as a tool in the
development of site specific water quality standards
needs to be greatly expanded,
2, The level of desired protection, commensurate with the
protection of environmental integrity, needs to be care-
fully specified so that the performance of various
protective strategies can be evaluated,
3. Laboratory toxicity tests are useful for the derivation
of national water quality criteria, but since criteria
derived from such tests alone cannot consider local
ecological interactions, they should not be converted
into site-specific standards without studying effects
at the ecosystem level.
4. The statistical procedures for the site-specific criteria
cannot be substantially improved in the absence of local
data by which relevant ecological dynamic states may be
defined, measured, and modeled. For this reason, we do
not recommend that the basic calculation procedure be .
modified.
5. The "indicator species procedure" is based on a number
of assumptions which are presently unverified. This
procedure has often generated contradictory results in a
series of test•cases* We recommended that this procedure
not be used until further research has demonstrated its
applicability,
6. The proposed filtration method for the speciation of
heavy metals is inadequate. The Agency should determine
the most appropriate method for estimating the bio-
logically active forms of each individual pollutant.
7. The Agency should complete development of the "historical
procedure," including procedures for required monitoring,
8, Actual residue concentrations and their environmental
dynamics should be given precedence over laboratory-
derived bioconcentration coefficients in the derivation
of site-specific final residue values*
9. The Committee urges the Agency to continue its develop-
ment of site-specific guidelines and not to abandon such
efforts because of initial criticisms.
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PROBLEM STATEMENT HO RESOLUTION
The problem of environmental protection against toxic
substances in the aquatic environment is poorly specified.
Limitation of Yoxicity Testing
F. L. 92-500 mandates that the integrity of the environment
be protected* Yet, water quality criteria and the proposed
site-specific standards are largely based on acute and
chronic toxicity testing of single chemicals on single
species in laboratory settings. Interactions between exposed
species, between chemicals in the form of potentiation or
antagonism, and of chemicals with ecosystem properties are
ignored in the proposed methodology used to set site-specific
standards. Therefore, current methodology can be appropriate
in concept if and only if all of the following parameters
are either satisfied or produce a negligible effect;
1* The appropriate species have been tested based on
ecological importance and human uses* particularly
consumption, taking into account toxic residues.
2, The exposure is environmentally realistic in terms
of physical and chemical identity.
3. The stresses under laboratory conditions not related
to the toxicant are equivalent to the non-specific
stresses found in 'the environment.
4* Interactions with other components in the environment
produce insignificant effects,
5. The toxicant has no effect on interactions between
species, such as competition, predation, commensalism,
or parasitism.
6. The toxicant produces no .other effects on the ecosystem
that may affect the test species indirectly.
It seems unlikely that all of these conditions will be met in
the vast majority of cases in which toxicants are tested in
the laboratory and the results are subsequently applied
directly to natural systems.
Thus, while single species toxioity testing in the laboratory
provides important information, e.g.', relative toxicity of
compounds or relative sensitivity of species under specific
laboratory conditions, that information is incomplete for
setting appropriate standards for the protection of the
environment as mandated by P,L. 92-500.
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Standards, which are exclusively based on laboratory toxicity
testing, would therefore be accurate not by design, but by
eiiance. it times such standards appear to be overly pro-
tective, but at other times they fail to protect adequately,
The reasons why the standards appear to protect more often
than not may result from the various conservative approaches
built into the criteria and standard-setting procedures,
go 1 e of. Toxioity_Data
Bioassays are generally performed on a few selected life
stages of a selected number of species under controlled
laboratory conditions. Response dynamics are very sensitive
to the experimental conditions; and, therefore, great care
must be taken to manipulate only those variables which are
subject to testing. Inadvertent variations in nontest
variables will contribute spurious components to the observed
behavior, masking effects of the intended treatment.
* Rigorous control of test conditions by careful
choice of subject popuIatiQn.3j,,_ad_e_quate replication,
and adheren_Qg_jbq experimental design_j.s_rjessentia.l
in toxicology testing.
In spite of such shortcomings, it would be inadvisable to
abandon laboratory toxicity testing. However, it is important
to utilize such data with full cognizance of their limitations.
While standards calculated in such a manner lack the logical
basis to serve as appropriate standards for the protection of
the environment,, they can serve as first approximations,
subject to verification by monitoring arid verification in those
ecosystems to which they are to be applied.
Since the national criteria do not consider interactions
between species and with the environment,
* site^specifio sta£dard3 which are direct
conversiQnsii of, national criteria can_only be
considered as provisional standards, subject
to field ^verification th,r_o_ugh^ monitoring.
To transfer bioassay results to field conditions, it is impor-
tant to consider that the response of a system to a fixed set
of conditions may change because of an offset in time. In
general, this is a difficult property to establish, but it
cannot be simply assumed. Procedures to establish this should
be incorporated into protocols.
* Minimally, i;_on_ly data obtained at comparable
times of day, year, eto. should be compared.
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Issues Related To Toxlolty-Based JData
Te£3t__Species Selection
A critical component of the Guidelines for Deriving Site-
Specific Water Quality Criteria is the development of a
minimum data base on the acute toxicity of chemical to
species selected from eight taxonomic families. These
families in freshwater include four fish families, a
piasktonic crustacean, a benthic crustacean, and a repre-
sentative of a phylum other than Arthropods or Chordata. To
develop a final salt water acute value, species must also be
tested from eight families so that all of the following are
included; two families in the phylum Chordata, a family in a
phylum other than Arthropoda or Chordata, either the aysidae
or penaide family, three other families not in the phylum
Chordata or any other family. The apparent objective of
requiring acceptable teat results for species in eight dif-
ferent families to make up a minimum data set seems to be
based on a desire to have results from a cross section of
aquatic life'(i.e., several families from different phyla).
This is apparently to recognize the fact that aquatic
organisms differ in their responses to chemicals or that
what is needed is ^a definition of the range of responses.
Since it is not possible to test all aquatic life to derive
acute toxicity information, the Guideline establishes eight
species as surrogates for all untested species* Can test
results' from eight species adequately define the range of
response of all species? Recently an SPA-OTS sponsored work-
shop on the surrogate species concept concluded that
individual apecies are not necessarily representative of any
larger subset of different species; however, a group or
cluster of species may have a relationship to the probability
of effect in a wide range of other species. The surrogate
species cluster concept was endorsed 'by the workshop
participants and appears to be in concert with the approach
used in the Guideline, The surrogate species concept was
developed by taking an introspective examination of aquatic
toxicology data bases for a variety of chemicals with a
variety of organisms. Don Mount and Wes Birge examined these
data bases and concluded that acute toxicity test results on
U-5 species, irrespective of taxonoraic classification,
adequately defines the range of response likely to be found,
even if a larger number of species were tested. Therefore,
it appears that requiring as a minimum data set toxicity
data on species from eight (8) families has some basis and
is partially defensible.
However, there.are several potential problems with the concept
of using the taxonomic level of family as a means of selecting
species to test. For example, individual species within a
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family may possess quite different toxic responses. The
Guideline, therefore, leaves too much flexibility in the
choice of species to test. With the existing guideline it
would be possible for an unscrupulous person to select an
insensitive species in each family and thus derive a final
acute value which is higher than would have been determined
if more sensitive species had been selected. Perhaps the
guideline should require that if information is known about
the range of sensitivities of species in a family to a
candidate chemical or to a chemical of similar structure
that those species exhibiting a sensitive response should be
used. Likewise, the Guideline should recommend that keystone
species and rscreationally and/or economically important
species be included in the minimum data base for determining
the final acute values. Keystone species are species whose
elimination from a particular aquatic ecosystem would cause a
drastic collapse of the system. A final criterion and perhaps
the most' important criterion in -selecting species to determine
the range of response to a chemical is that the species
selection should be based on physiological and/or biochemical
characteristics. Species making up the minimum data base
should possess a diversity of physiology and/or biochemical
profiles. Simply requiring testing of representatives from
eight families of aquatic organisms does not necessarily
insure a wide diversity of physiological and biochemical types.
The Committee is concerned that the Agency fails "to communicate
a clear understanding of the difference between selected species
and geographic specificity.
In addition to questions related to the geographic distribution
of species and their varied responses to toxic substances,
unique ecosystem characteristics also vary geographically.
Clinal variations in terms of latitude and elevation contribute
to the potential for ecosystems to absorb, transport, degrade
and sequester toxic substances. Factors related to stability,
diversity, resilience and the amplitude of disturbance from
the system trajectory can be geographically specific and in
the context of this report, site-specific. The impact of
altering national water quality standards based on site-
specific testing may be time related as a result of geographic
specificity.
Recommendations for the collection of site-specific infor-
mation to vary national water quality criteria should consider
geographic specificity. These differences are related to the
many physical and biotic components which influence ecosystem .
function and consequently how systems might be more or less
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responsive to altered pollutant input without being degraded
from their current or potentially higher human use.
Statistical Issues in the Site-»gpecific Water Quality Criteria
For a given pollutant, the guidelines for deriving site-
specific criteria are adaptations of the corresponding
national guidelines. While it is not appropriate to review
the national guidelines here, it is necessary to briefly
state their statistical basis to put .the site-specific
methodology in context.
The national guidelines define a tvo-part criterion: one
part is intended to be protective against acute effects; the
other is intended to be protective against chronic effects.
The acute value is found by way of a distributional approach,
taking the maximum-instantaneous concentration as one-half
the estimated fifth percentile of the distribution of family
geometric mean LC^Q values. The chronic value is often
used as a maximum 30-day average concentration. It is calcu-
lated by dividing the estimated fifth percentile of the
distribution discussed by an estimated acute-chronic ratio.
For compounds that bioacoumulate, the 30-day,average concen-
tration may be determined as a concentration to protect
organisms which feed on aquatic life, if this is lower than
the chronic number.
The national guidelines contain provisions for adjusting the
criteria as a function of variables, such as hardness, that
affect toxicity. They also provide a range of sensitivities
by insuring that the family mean LCgg values satisfy a
minimum data base requirement.
Essentially every feature of these calculations has been
subject to some reservations. The principal comments are the
following:
1. There is no clear statement of the degree of
protection the resulting criteria afford, beyond
the claim that most species are protected most of
the time.
2. The species on which the LCgo's are available are
not representative of the nation or of any
particular site.
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3» The method for calculation of the fifth percentile
is unduly sensitive to the number of points in the
distribution of average LCgo's,
4. The average acute-chronic ratios are not statistic-
ally or biologically valid.
5, The reduction of the fifth percentile by one«half
is not justified by any scientific analysis.
6. A 30-day average concentration does not protect
against effects which can occur over a shorter
time.
Related criticisms concern the criteria for admitting an
to the data base on which the criteria are calculated, the
choice of family versus species means, and alternative choices
for estimation of the fifth percentile.
All of these comments are relevant to the site-specific
statistical methodology. However, the statistical procedures
for tne site-specific criteria cannot be substantially improved
in the absence of local data by which relevant ecological
dynamic states may be defined, measured, and modeled. For
this reason, we do not recommend that the basic calculation
procedure be modified. Nevertheless, the validity of the
comments must''be accepted, and if must be concluded that the
site-specific criteria will not, as a matter of logical
necessity? protect the integrity of the biological community.
Desired Environmental Quality—Definition^cyMSnvironfflental
Integrity
The Clean Water Act mandates the protection of the physical,
chemical, and biological integrity of the environment. These
general goals have not been sufficiently translated into
specific guidelines baaed on the required degree of environ-
mental protection commensurate with the intent of the act,
It is important that these goals be stated in terms of
environmental parameters rather than laboratory based para-
meters, so that the performances of various protective
strategies can be evaluated for their efficacy.
The development of a more detailed statement of goals for the
protection of environmental integrity is not easy, and because
of limitations in time, the Coiuaittee was not able to develop
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a set of operational goals which could be readily adopted by
the Agency. However, the Committee was able to identify a
number of important issues.
Absolute protection of the aquatic environment from human
impact may be considered to be our intangible goal. However,
such a goal is clearly unattainable, even if there were no
economic, societal, or political constraints. Any speqies,
humans included, cannot exist without affecting the environment
or being affected by it. The need for strategies to protect
the•environment is strongly influenced by human population
densities and by the effluvia of municipal and industrial
activities which are associated with human life-styles.
While it is not possible to return to an environmental state
which is based on the premise that humans have never existed
and do not 'produce a present impact, it is possible 'to reduce
human impacts*
The development of operational guidelines for the protection
of the integrity of the environment needs to consider a number
of factors. Ecosystems are dynamic entities, and thus they
exhibit natural variability over time and space. When an
ecosystem is challenged by pollutants, it does not necessarily
stop functioning, but enters a new dynamic state and, in
doing so, may maintain its integrity,. 'To'date, the new dynamic
state has been judged'not only by objective parameters, but
has also included considerations of the subjective desirability
of the new ecosystem state, based on its suitability for
single species, such as trout.
Therefore', the normal variability of ecosystems and our
generalized expectations cf the required degree of protection,
coupled with the intent of using the ecosystem for a number
of purposes, results in a situation filled with conflict -when
one attempts to set guidelines for the protection of the
environmental integrity. To prevent greatly differing
interpretations of the required degree of protection by every
state, municipality, and industry, the Agency should establish
further guidance based on environmental parameters.
Specification of theJEnvironmental Protection Problem
lather than developing site-specific standards from laboratory
toxicity data alone, dynamic perspective is needed to improve
EPA's present toxicology-based approach. An environment,
to be protective for a certain set of uses, consists of sets
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of ecological conditions, species, resources (including
toxicants of interest)j and interrelations within and
between these categories—all dynamically changing with time.
Thus, environments are dynamic systems driven by sets of
inputs to generate time dependent behavior, which can be
viewed as outputs. Mot all outputs can be measured to assess
the state of health of an environmental system; the problem
is to assess the condition of the environment from a restricted
set of carefully chosen diagnostic variables. Protection or
nonprotection of these variables must reflect success or
failure, respectively,' in protecting the subject environment,
To achieve this, the diagnostic variables must be chosen so
that this protection bears both sufficient and necessary
relationships to the larger set of ecosystem variables which
denote an environmental condition.*
Environmental changes occur because of the influence of both
conventional pollutants and toxic substances. These changes,
constituting perturbation dynamics, can be compared to nominal
(unperturbed) behavior to provide a measure of impact. When
deviations exceed prescribed bounds, represented by standards,
the subject environment is considered unprotected; otherwise
it is protected up to the specified standards. The objective
of environmental protection, then, is to maintain differences
between perturbed and nominal behavior within limits defined
by the standards. Since it is•inefficient and probably
impossible to measure all of the output variables of an eco-
system at the present tine, the operational problem is to find
a subset of diagnostic environmental variables which reflect
the behavior of larger set of ecosystem output variables*
If the diagnostic output variables have been properly selected,
then as long as the diagnostic output variables remain within
specified limits (standards), the output variables of the
entire ecosystem would also remain within specified conditions.
Choice of DiagnosticVariables
The logical basis of choosing a set of diagnostic variables is
critical and should be approached through careful study of
each site-specific problem. Diagnostic variables should
* A more extensive treatment in terms of system theory
is attached as Appendix 1.
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embrace ecological and toxicological considerations, include
system level abiotic and biotie variables, meet both short-term
(acute) and long-term (chronic) diagnostic needs, include
invariant elements to standardize across all possible national
sites, arid include variant .elements which reflect site
specificity.
EPA should pay close attention to conditional logic in
establishing necessary and sufficient conditions required to
relate protection of diagnostic variables to that of the
larger set of ecosystem variables. The protocols developed
should contain procedures which unequivocally establish these
relationships for each site-specific problem.
Present practice has not generally included these important
logical considerations, and
;H
* there is_.__a_ definite resea ';ch need_tg better identify
the appropriate dia.gnosti'c variables for the, evaluation
of environmental integrity.
Environmental Monitoring
Since it has been established that laboratory-based studies
alone provide only an imperfect foundation for site-specific
water standards, no matter what system of calculation is
employed, environmental integrity needs to be assessed by
means which are more closely connected to the environment.
Therefore}
* the Committee strongly recommends a greatly expanded
role for environmentalaonitoring_in the development
of site-specific standards«
There are three types of monitoring—chemical, physical,
biological—and at least five purposes of monitoring. Baseline
monitoring requires choice of diagnostic variables, determination
that these are necessary and sufficient to represent ecosystem
behavior, spatial and temporal design of sampling, and data
assembly, analysis and presentation. Monitoring for impact
detection is a different problem for chronic and acuteeffects,
and, in addition to the above considerations, concerns
definition of suitable standards. Compliance monitoring is
an ongoing version of impact detection, but otherwise may be
similar to impact detection. Monitoring to establish causality
is a technically difficult problem and hinges on the logic
underlying the monitoring effort. Specifically, a necessary
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and sufficient relationship must be established between
suspected cause and observed effect. Then, if the cause is
present, the effect will be seen in monitoring data
(sufficient), and if the cause is absent, the effect will
not be observed (necessary). Monitoring for prediction is
also technically difficult because it involves a time offset.
Protocols forEnvironmental Monitoring
Since the onset of monitoring as a vehicle for overseeing
environmental integrity, the agencies involved (usually
government at all levels) have moved slowly in making
necessary changes in accepted protocols and methods. This
is understandable in the sense that
1, baseline data are either wanting, scarce, or
difficult to obtain;
2. governments have not, in general, carried out
short-term or long-term research for meeting such
methodology problems;
3* general acceptance by the scientific community is
usually awaited prior to the institution of tactical
revisions;
4, new chemical products and new toxicological problems
are constantly emerging; and
5. ecology has only recently started to emerge from a
descriptive to a systematic science—and is still
emerging.
The results of this sequence.of developments, along with an
ever-increasing list of environmental knowledge requirements,
have been a mixture of monitoring systems in dire need of
technical and logical revision. Among the practices commonly
in use are the following:
1, The monitoring of aLI possible factors and then
using derived standards from best available infor-
mation. This would include, for example, continued
periodic measurements of metals, nutrients, plankton,
bottom fauna diversity, whether or not they were
pertinent, and then using fixed values, excursions
beyond which constitute a violation.
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2. The use of certain tools or criteria as monitoring
bases which were once derived for a specific reason
but which are now misused, in disuse, not up-to-date,
or have been surpassed* There are many examples of
these. An outstanding one is the setting of a single
dissolved oxygen standard for all waters and the
labeling of this standard as a "natural" level below
which are levels of violation. An example of this
technique is the current methodology of collection
and measurement of oil and grease in native waters.
Another is the inflexible adherence of some agencies
to bottom sampling methodology and statistics despite
bottom-type differences. This same attitude of
inflexibility pertains to the use of a fixed array of
bioassay organisms despite the varying conditions
among areas under observation,
3* The use of a strictly toxicological approach to
monitoring based only on LCCQ'S or chronic health
problems in specified organisms.
4, Monitoring for indefinite periods, which may be overly
frequent or infrequent, and are not necessarily designed
to include events of natural frequency.
The above approaches have within then strategies and tactics
which need to be retained or updated. Rejecting them out-of-
hand without review is not constructive. (The value of this,
i'f nothing else, will be to point out complex problems and
approaches to be avoided. This is the principal "value" of
the'several interim site-specific reports which we have
looked at,) At the same time, Agency use and accompanying
enforcement, when done in the narrow sanse, is not only
unconstructive but would also diminish progress towards our
understanding of environmental reality. What is strongly
suggested here is an intensive, periodic review and update
with accompanying rules and technologica-1 changes, as needed,
of monitoring protocols, (This is an essential step after
an agreement is reached between a State and EPA.)
Periodically, there must be a review followed by necessary
revisions and updates. It is also essential that the review
group- be composed mostly of people not employed by the
government. These remarks apply to all governmental agencies
that monitor, which have a national overview, and whose
regional offices often are looked upon as ultimate arbiters
in regional ecology.
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* What is needed first is a full description of .the
reasons for the existence_of monitoring programs at
strategic and tactioal_levels*
Second, the protocols and technologies adopted must justify
these reasons, be altered until they do so, or be rejected.
By way of example, the phrase "best available information—or
method" should only be a signal of needed information and a
direction indicator for finding it. Also, the laws promulgated
on clean water, air, etc* should be anticipated enough so that
the kind of monitoring protocols needed as part of their body
should also be anticipated. A sincere effort in this direction
is not only economical but also avoids methods that are on
the one hand expedient, but on the other do not fulfill the
principles of whatever philosophy is derived. The case
studies examined are an example of what can happen when time
constraints are put on an investigatory team. Anticipation
of method application, seasonal and diurnal changes, experi-
ment a,l planning of sampling techniques, and tryoutsL in the
field should be an integral part of every case study*
Issues
1. The Purpose of Monitoring
Unless there is an end-product that is usable and
justifies' the principles directly or indirectly, then
we only have monitoring for its own sake or to satisfy
an arbitrary standard. In addition to practicability,
monitoring should provide data and information for
storage and retrieval in a cross-referential sense.
Let us consider what it is that monitoring is supposed
to show.
* a. Monitoring should indicate when a designated
level of substance istreached ina medium or
organism, or,__where pertinent, in a system of
mediaand/or organisms•
With respect to organisms, the protocol should involve
one or more of the following types:
1) organisms which concentrate a substance(s)
significantly and are a significant part of
the food chainj
2) those which show pathology and which are a
significant part of the local system. (This
may eliminate transient forms and those which
occur infrequently and in insignificant
numbers.)
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With respect to media or systems, the following factors
should be considered:
1) Is the medium itself part of a system, i.e., in
this ease if it is part of a stream, are
partioulates in a transient state or prolonged
suspension state? Is the bottom scoured and/or
penetrated by upper waters and to what extent?
Are the sediments chemically active, etc?
2) Is (are) the substance(s) dissolved? x In
suspension? On or associated with particles?
In the sediaenta and, if so, distributed in
interstitial spaces, sorbed on surfaces,
ionically bound, etc?
3) Is the substance distributed in more than one
of these states'and, if so, is there equilibrium,
steady state, or some other reactive order of
distribution, half-life, etc?
• b. Monitoring should indicate Jihe factors which
aodif'y_ the chemistry/physics and the biological
effects significantly,
This may involve the.status of the local environment
of the substance(s)' monitored or the effect of the
substance on the organism tested.
One oust select among the various possible chemical
and physical factors for those which involve quanti-
tative correction of measurements, e.g., temperature
of water and oxygen, solubility, salinity and pH,
etc., and those which bring about chemical changes,
e.g., pH and ionization or solubility, dissolved
oxygen content and nitrification, etc. It must also
be remembered that these factors may affect the uptake
processes of organisms or change the chemistry of a
concentrated substance in a food-chain organism when*
the latter is consumed by a grazer or predator.
Usually after a certain amount of background study,
many of these factors can be spot-checked* and the
number of analyses reduced, or, because of interactions,
control factors may be predictive of other ones, e.g.,
the components of an alkalinity system, once the
interaction is established, can be calculated, after pH
is measured.
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Here one must not forget the importance of seasonal
change as an overall control of environmental inter-
action.
There are enough ecological studies available that one
can select Influential physico-chemical factors.
Many agencies do not do this and end up with quantities
of multiple factor data for- which there are no realistic
correlations. The great, disadvantage of this is not
so much the accumulation of useless information as the
fact that, while carrying out this type of monitoring
function, influential factors may be downplayed or
overlooked.
o. Monitoring should show which bioeffects are
indicative of the degree, of severity of the
toxic problem.
Up until now almost all reports deal with LCgg's
and chronic effects. What may be being overlooked is
the body of information that deals with other effects:
1) Behavioral changes of movement, habits,
feeding, etc.
2) Degree of growth using possibly mark-and~
recapture techniques among animals; mark and
measurement among plants; mass increase in
microplant or mic.roanimal populations over
short periods; periodic size distribution
• measurements among captured or sessile '
• populations.
3) Fertility measurements which can be done in
various ways among a variety of organisms.
The question arises as to what adverse effects
on fertility can show. First, among small
organisms, they are the early warning systems
that can predict the onset of lethal and
chronic effects among larger organisms.
Second, they nay be measureable and take
place at known fractions of lechal and chronic
effects when occurring either in micro- or
macro-organisms. Third, they may be indi-
cating that lethal and chronic events are
being partially masked in some organisms by
an environmental effect, e.g., weak sorption
on clay particles. Finally, these effects,
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though not lethal at the moment, of measure-
ment, may either result in the death of the
organisms individually or portend the limit-
ing or elimination of a population affected.
Judicious use of a, through c. should yield a. series
of criteria that will be predictive when used together
with proper protocols derived from the other issues
to be discussed. The effectiveness of this use of the
criteria can be evaluated by field measurements of
selected species' population samplings. Some of the
measurements implied are done in the field (mark and
recapture); some are done in the laboratory (behavior
studies). In- the latter case, however, if one is
fortunate in the choice of organisms, the laboratory
study indicates the type of behavior expected in the
presence of known levels of toxic agent.
2, Organisms to Use in a MonitoringStudy
The original idea of the choice of test organisms
for toxicity studies was to give an array of reactions
through the phyla of animals that would cover important
vertebrates and invertebrates and provide a usable data
base, Thege then, on the bases of LC^Q'S and chronic
effects, could be applied to the setting of standards
for levels of toxic substances in the environment.
With time, there has been a., tendency toward standardized
use of certain species which apparently have been chosen
because of what has been regarded as their "importance"
and/or their sensitivity. The implication here is not
that these were or are bad criteria or that their use
should be disregarded. What is implied is, for site-
specific protocols, that regional authorities should be
leaning more toward local ecology both abiotic and
biotic. This means that one should learn which
population systems 'ars operative, what is the impact
on species diversity and biomass, which trophic levels
are being dealt with, and, finally, rather than
determining the sensitivity of the organisms to a
particular toxic compound, first determine how important
the various organisms are in the system and then choose
among the most important for the desirable degree of
sensitivity.
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The term "importance" can be given statistical or
numerical value just as can "sensitivity," Usually
it has to do with the largest number* of particular
species, but this can also be weighted in terms of
how they function in the different trophic levels.
Thus, for a particular water/wetland system, one
should determine a differential quantification of
the operative systems, including, among the flora,
at least the microplants. It is understood, of
course, that some organisms are more motile and
transient and require number estimation techniques
that are more consistent than accurate. After
the quantification study has given sufficient data
to give a usable view of the system, an importance
figure should be ascribed both to those species
present in large numbers and to those important in
the trophic levels* Then a system should be devised
for choosing among them with regard to sensitivity,
taxonomic level, and species of particular interest,
probably in that order.
3, Fregu_ency of_riMonitorin g
As mentioned above, monitoring agencies may frequently
employ a variety of measurements, especially'abiotic
ones, and end up with counts for which there is often
no correlation or which do not give a truly good
background picture. This criticism also applies to
the frequency with which the measurements may be
taken.
The following apply to physico-chemical measurements
of wetlands, water bodies, etc,
a. Time of day. Such factors as dissolved oxygen
and pH change 'diurnaliy, and at any particular
site there should be night as well as day
measurements. It is not necessary, however,
to measure these on an hourly basis, unless
there Is a known dependent reaction occurring,
e.g., elevated pH causing precipitation of
carbonates. Otherwise, this is a waste of
effort, Therefore, one will plan the necessary
hours for abiotic determinations initially
and cut them down to the minimal number of
subsequent determinations.
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b. Season. It may also not be necessary to
measure conditions on a monthly basis
continually. For the most part, measurements
at the peak of the season and at the
transition should tell what water condition
changes will be. After these are established,
it may only be necessary to measure the peaks.
One should also be on hand to measure major
occurrences such as major storms, spring rains,
snow oielts, etc.
o. If gradients from effluents.to spring rain
runoffs occur, these should also be noted and
monitored.
d.' If there is an intimation of possible stream
•contamination of a known type from a known
'source, the Agency should be prepared on short
notice to measure downstream gradients,
e.i It is apparent from 19 site-specific studies
submitted to us for review that, to assure
the information necessary to retain environ-
mental integrity, some tighter specifications
for the conduct of such studies should be
written. Due to seasonal, diurnal, and
meteorological or> hydrological events,
chemical and physical parameters are
constantly changing, as are, the populations
of organisms in' a stream. It seems logical
that either sampling and monitoring must .
bracket these variations or other studies
must be referenced to deduce how these
changes with time will alter response of the
organisms to toxic substances or alter the
physical or cheaical state and availability
of those substances to affected organisms.
f. Also to be taken into consideration must be
the physical dimensional effect on seasonal/
time measurements, i.e., the depth of water,
•the influence of bottom in shallow waters vs.
deeper waters, speed of currents, influence
of shoreline, vegetation overhanging shore,
etc.
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With respect to organisms, measurements should be made
according to the above criteria if advisable only and
at other such times as may elucidate some part of the
life history that may be pertinent to the toxic study
of concern.
4. Monitoring Feedbacks
One should be able by means of control situations and
localities to set up a background picture or noise
level of the important parts of the system under study.
One must also decide on the levels of significance
which depart from this "norm," both in degree and in
time. From this, one should be able to decide when
some pathology is occurring at the site area and possibly
which groups of organisms are moat affected. Selected
tests for toxicology, as discussed above, may then
ensue.
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SPECIFIC PROCEDURES IN THE GUIDELINES
The proposed guidelines suggested that site specificity could
be achieved through the application of one or more procedures,
which can be briefly summarized as;
1. A "Recalculation Procedure," which recalculates the
criteria by taking account of differences between the
species tested as part of the national data base and
those species which actually occurred or were expected
to occur at a local site. This procedure is basically
an extension of the methods for the derivation of the
national criteria based on laboratory toxicity testing.
2. An "Indicator Species Procedure," in which acute
bioassays are conducted in site water and in defined
laboratory water to derive a ratio which represents
the impact of local water quality. This ratio is then
applied to the national data base.
3. A "Resident Species Procedure," in which the national
toxicity data base is repeated for both acute and
chronic toxicity using local species in site water.
4. A "Heavy Metals Speciation Procedure," which depends
upon the metal concentration in a 0,45uffl filtrate,
rather than total metal concentration,
5. A "Historical Procedure," which sets the site-specific
standards at local concentrations when it can be
determined that these concentrations produce no adverse
effects. This procedure-is still under development.
6. A "Final Residue Value Procedure," which is essentially
identical to that in the national water quality criteria
methodology and is based on laboratory data.
These methodologies were examined in detail, and their evalu-
ation follows.
Recalculation Procedure .
The Recalculation Procedure is intended to account for the fact
that some species which are represented in the national data
base may not be present at a site. To remedy this, the site-
specific criterion is calculated by removing the average LC§o
values of the absent species from the data base on which family
mean LCejQ values are calculated. If removing these species
reduces the data base below the national minimum data require-
ments, new bioassays would.be run, or the national family value
retained.
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The Water Quality Handbook presents several caveats concerning
the validity of any resulting criteria* The principal
statistical hazard is that, if the number of families is
reduced, the site-specific instantaneous maximum will be lower
than the national criterion, all other things being equal.
Since the rate at which the distribution increases necessarily
goes up as the number of data points goes down, the estimated
fifth percentile will necessarily be lower. Consequently, it
does not appear that this type of effect can be eliminated as
long as interpolation from the empirical distribution function
is used to define the instantaneous maximum.
Since the recalculation procedure is based solely* on laboratory
toxicity data, and is, in fact, a modification of the national
water quality criteria guidelines, it is subject to the same
criticisms as the national guidelines. The major criticisms
are that interactions and ecosystem properties are ignored, and
that the taxonomic basis for the selection of test organisms
does not reflect ecological structure or importance,
Indicator Species Procedure_J_Water Effects Ratio)
This procedure assumes that differences in water chemistry at
individual sites may modify the availability and thus the
toxicity of specific chemicals.
The Indicator Species Procedure is intended to cover the case
in which the range of sensitivities of resident species is the
same as that in the national data base, but the toxic effect is
modified by the characteristics of site water. The procedure
allows three ways to calculate the chronic value which usually
determines the 30-day average concentration. If available, the
national acute-chronic ratio may be used. Alternatively, three
matched pairs of acute and chronic tests on at least one fish
and one invertebrate may be run using site water. The geometric
mean of these three acute-chronic ratios is then used as the
acute-chronic ratio for estimating the chronic level. Finally,
a State may conduct acute and chronic tests on a fish and an
invertebrate in both laboratory and site water. Prom these
data a geometric mean chronic water effect ratio is calculated,
then multiplied by the national acute-chronic ratio to find the
ratio applied to the estimated fifth percentile.
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The acute value is found by adjusting the national value by the
geometric mean of the ratios of the site water LC^Q to
laboratory water LCgQ, if this ratio is significantly different
from one. Otherwise the national value is the site-specific
value. The site water and laboratory water LC^Q'S, which are
averaged, are based on one fish and one invertebrate species.
is described in the Water Quality Handbook, the choice of
species to be tested and the sublet of the national data base
en which the criterion will be derived are determined by the
State, depending on the situation, at each site. There is
general guidance on these choices through a schematic workplan,
and caveats are given concerning the main features of selecting
the indicator species and running the required laboratory tests.
Because of the freedom granted the States in designing the
studies for implementing the Indicator Species Procedure, it is
difficult to assess the validity of criteria developed from
this protocol, Unless Agency scientific staff are involved in
planning and conducting studies implementing this procedure,
different criteria may result for similar sites, due to
different choices among the allowable alternatives. It would
be helpful to provide a decision-tree for this procedure,
together with guidance on the conditions under which each
branch would be followed.
Statistically, the Indicator Species Procedure raises the
question of the appropriateness of the small sample sizes for
species and the ratio form of adjustment for acute and chronic
water effects. The assumption is-'that the average of two or
three species, some of which may us in the same family, provide
data sufficient to adjust the distribution of family means by a
constant of proportionality* Whether this can be successfully
done, and for which pollutants, is a basic research issue which
has not been resolved at this time.
From a biological and toxicological point of view, criticisms
of the Indicator Species Procedure include (1) the assumption,
in order to use it, that no species response differences exist
between resident and national data base species, which' is
unrealistic; (2) "acceptability" for nonresident indicator or
surrogate test species is not defined; (3) apparently, any two
species of a fish and an invertebrate may be used in testing
for chronic toxicity; and (4) the methods presented in this
section do- not provide adequate procedures for assessing the
relative impact of various site waters on bioavailability
and/or toxicity.
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It a more specific level, these procedures call for simultaneous
acute tests in "site and laboratory dilution water," but neither
of these waters is adequately defined. This is of particular
concern for site water where the underlying assumption seems to
be that waters collected from a site in an unspecified manner,
and transported and stored under unspecified conditions,
will bear some resemblance to the water on site. The chemical
characteristics of site water, however, are in large part a
consequence of other factors at the site (e.g., pH, DO, salinity,
temperature), which determine the availability of the chemical
in question (Sunda and Hansen, 1979) and may change considerably
on storage.
Moreover, water on site is in equilibrium with the substrate
of that site, rand disruptions of these equilibria among trans-
port and storage may alter the availability of existing cheaical
species in the "site water." These modifications and the absence
of the original rsubstrate make extrapolations from laboratory
tests of site water to actual on-site conditions difficult,
Also many of the factors mentioned above vary in site waters on
a daily basis-and seasonal basis, which could cause substantial
differences in water effects ratios depending upon the time of
day or year in which the water was collected, (See, for instance,
draft report of Iowa .River.)
These issues are mentioned in passing in the procedure (see 3-
34). This discussion, however, merely cautions that the- site
water should be used "as soon as possible after collection"
and that "care should be takes to maintain the quality of the
water" and any changes should-.be "measured and reported."
While acknowledging the potential for problems, these statements
provide little useful information as to appropriate storage
time, transport conditions, or the type or degree of changes
which are, considered acceptable/unacceptable. Furthermore, this
discussion implies that flow through testing on site is more
appropriate for dealing with problems in diurnal water quality
cycles but does not address the actual issues of diurnal cycles
or how this procedure would be applied.
Another issue left unaddressed in this section is the problem
of sample contamination during collection and storage. Recent
studies in marine chemistry have demonstrated that standard
collection, storage, and analytic procedures resulted in metal
contamination which produced metal concentrations several orders
of magnitude higher than are now routinely measured in water
samples (Patterson and Settle, 1976). It is also becoming
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apparent that elevated metal levels due to metal contamination
may be' sufficient to inhibit growth in phytoplankton (Suoda and
Guillard, 1976; Anderson and Morel, 1978) and to affect
phytoplankton metabolism to the degree that primary production
measurements are significantly altered. (Fitzwater et al., 1982).
A recent study with crab larvae also has demonstrated pertur-
bations in growth at cupric ion activities' just beyond ambient
levels in the estuary from which the crabs were obtained
(Sanders et al., 1983)* These studies point out the importance
of using carefully controlled cleao procedures when collecting
samples for water chemistry and biological effects studies.
These clean procedures have been described in literature
(Patterson and Settle, 1976; Bruland et al., 1979; and Fitzwater
et al», 1982) and should be reviewed, modified, if appropriate,
and incorporated in section B before it is implemented.
The use of acute/Ghronic ratios in this procedure also presents
potential problems. In the first example on page 3-26, the
site specific final chronic value can be obtained by dividing
the national acute/chronic ratio into the site specific final
acute value. This procedure assumes that the acute/chronic
ratio derived from studies with laboratory water has some
absolute reality and can thus be applied directly' to data based,
at least in par.t, on site specific assays. Hecent studies with
both metal and organic contaminants, however, make it clear
that the mechanisms for acute and chronic effects may be quite
different, and, as a consequence, these responses are not
directly linked. While some consistency can be obtained in
replicate experiments, where procedures are limited to a single
variable, the validity of applying a national ratio to a site
specific acute value, which is based on different and less
defined procedures, has yet to be established.
A final point is drawn from the draft report on criteria
modification for Selser's Creek, Li, prepared by J.R.B. In
this report, water effects ratios were determined for Cd and Pb
using the pigmy sunfish (Elassoma z o n a t uap and the grass shrimp
(Palaemonetgs kadiakensusTIThe water effects ratios determined
using grass shrimp were 2 and 40 x higher for Cd and Pb
respectively than were those determined using the sunfish. The
reasons for these differences are not clear, but they serve to
point out the potential problems with the water effects ratio
as it is currently presented.
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As a result of all of the shortcomings delineated above,
• The indioator-speqiea...methodology should not
be used for the development of site«specific
standards untiltthetconcerns expressed have
been resolved through research.
Initially:
(a) Procedures for collection, storage and testing of
site water should be evaluated and a rigorous and standardised
procedure should be implemented,
(b) The problems of diurnal and seasonal variations should
be addressed in a more specific and rigorous fashion.
(c) General and specific limitations or problems in the
procedure should be more clearly defined and their implications
discussed. Ultimately the principles of this procedure should
be incorporated in a totally redesigned methodology which is
soundly based on ecological considerations.
Resident Species Procedure
The Resident Species Procedure essentially duplicates the
complete battery of laboratory toxicity tests required for the
minimum data base for the national criteria guidelines, but
does so in local site water. Subsequently, a site-specific
standard is calculated, the procedure is subject to the same
criticisms as the national criteria guidelines and the
recalculation procedure. However, if the appropriate
precautions on handling of local site water delineated in the
previous section are observed, then this procedure should
account for many of the influences of local water quality on
toxicity.
Heavy_IMetal Speciation Procedure
The national standards for metals are expressed as total
recoverable metal based on laboratory data on total recoverable
or acid extractable metal concentrations. Metals exist iii a
variety of forms, each with specific toxiGalogical potential.
There is substantial evidence indicating that the availability
and toxicity of aqueous trace metals is determined by the free
metal ion activity rather than the total concentration of ions
in solution (Sunda and Guillard, 1976; Anderson & Morel, 1978;
Sunda et al., 1978). In spite of the title, however, section D
of the Draft Water Quality Standards Handbook does not actually
address the question of metal speciation. lather it imposes
an arbitraty size limit (Q.45um) below which metals are
considered dissolved and thus potentially available.
- 29 -
-------
is pointed out by Stumm and Brauner (1975)', the filtration
approach is not an appropriate procedure for addressing the
question of metal speoiation. Metal speciation is controlled,
in large part, by the chemical associations of metals with
inorganic and organic metal binding ligands (Sunda and lansen,
1979). A crucial question in metal speciation is the strength
with which metals interact with the various ligands, which is
represented by the stability constant of each metal ligand
complex. These constants are, in turn, highly dependent upon
environmental factors such as pH, salinity, and DO (Stumm and
Brauner, 1975; Sunda and Hanser.» 197S)> but are not di%reotly
related to particle size. Thus, metals associated with low
molecular weight ligands with high binding constants may be
less available than metals associated with larger ligands with
lower binding constants. A probable example of this is seen
in the draft report on criteria modification for the south
fork of the Crow River, MN, prepared by J.R.B. In these
studies LCgo values for total Cu were significantly higher than
for dissolved, and attempts to use the filtration procedure
would be inappropriate. Clearly the filtration procedure
described in section D could greatly overestimate or under-
estimate the available metals in a water sample depending upon
the types and number of ligands available in the sample and
the physical and chemical characteristics of the water. The
current procedure, then, is both inadequate and inappropriate
for addressing the Questions of metal speciation.
In spits of problems with the current procedure, an under-
standing of metal speciation is clearly central to the deter-
mination of biological availability and toxicity of metals.
Until recently, technical limitations have made routine'.studies
of metal speciation in site waters difficult, if not impossible
(Stumm and Brauner, 1975). A number of current studies based
on electrochemical techniques, however, show excellent potential
(Nurnberg, 1980). Techniques such ss these, which directly
address the question of metal speciation, should be pursued
vigorously by EPA and should provide the foundation for any
metal speciation procedures.
The issue of the biological availability of toxicants is not .
limited to the chemical and physical forms of heavy metals as
they are affected by local water quality, but also includes the
physical forms of organic pollutants,
• The Agency should determine the most appropriate
methodsfor estimating the concentrations of
biglogioally_active forms of pollutants for eaoh
individual pollutant•
. 30 -
-------
Historical Procedure
The historical procedure is still under development. Its intent
is to set the site-specific standard at local concentrations.
when it can be demonstrated that the local concentrations do not
exert an adverse effect on the environment. The data required
to support such a decision are closely linked to the data
required for monitoring the safety of a provisional standard.
* The Ag_ency should__ complete the methodology for
the historical proceduret including procedures
for required monitoring;prior to setting the
standard at in-stream concentrations*
Final Residue V_alues
Residues of priority pollutants which are able to bioconcentrate
or bioaccumulate in aquatic biota are of concern when the
concentration of the residues reaches levels which exceed the
guidelines for human consumption, or when the concentration
of these residues reaches levels which may be hazardous to
wildlife which feeds on aquatic organisms.
Action levels or guidelines for residues in fish and shellfish
for human consumption are set by other agencies, but commonly
are intended to protect most consumers with an ample margin of
safety. These limitations also take into account that humans
do not exist totally on food derived from aquatic organisms.
The requirements for the protection of wildlife which consumes
aquatic organisms are less well established. In most instances
it is assumed that the residue limitations which are adequate
for the protection of human health are also adequate for the
protection of other consumers of aquatic life. For wildlife
species which consume aquatic life almost exclusively, the
adequacy of such a level of protection may be questionable.
It is necessary to exert a degree of control over the residue
concentrations in aquatic organisms to protect the consumers
of aquatic life. Once criteria for maximum allowable
concentrations in aquatic life have been established, the
easiest and most direct procedure may be to monitor the con-
centrations in aquatic life to assure that these maximum
allowable concentrations are not transgressed. Even though
the concentrations of residues in biota are monitored regularly,
to date the Agency has not incorporated the direct approach
, 31 -
-------
into its criteria and standard-setting procedures* Instead,
the Agency has chosen indirect approaches which seek to take
advantage of the relationships between the pollutant
concentration in water and the expected residue concentration
in aquatic biota.
The estimation of the residue concentration in aquatic biota from
water concentrations of the pollutant is based on the biocon-
centration coefficient (BCF), which is the ratio of the
residue concentration in the organism at equilibrium bo the
concentration of the pollutant, in water* The bioconcentration
coefficient can be estimated from the n-octanol/water partition
coefficient (Veith et al., 1979), from laboratory exposures
of fish or other aquatic organisms to the pollutant, or by
field studies. The use of the partition coefficient for the
estimation of the BCF is the least costly but is probably
also the least accurate, in many cases. The use of laboratory
exposures for the determination of the BCF under controlled
conditions would seem initially to be the best way to determine
the BCF| and, in fact, this procedure has become the mainstay
in Agency approaches concerning the limitation of excessive
residue concentrations in aquatic biota* The BCF values
derived from field data have often been found to diverge
significantly from laboratory-derived BCF values. Tc date,
these discrepancies between laboratory data and field data
have usually been cited to discredit the validity of the field
data, when instead these discrepancies should lead one to
equally question the validity of the laboratory data,
There are several important ways in which laboratory studies
differ from field observations, which could drastically affect
the determination of BCF values. The most important problem
is that most laboratory BCF studies fail to recognize
pharwacokinetic'principles. Regardless of the fine details of
the pharmacoklnetic model which underlies the true uptake and
clearance (depuration) of the pollutant, at equilibrium intake
equals clearance. The excretion rate constant is, thus, one of
the determining factors as to the duration required to reach
equilibrium (Branson et al,, 1975; Hartung, 1976; Neely, 1980).
Thus, an exposure duration of approximately 4 excretion half-
lives is required to approximate 95? of the equilibrium value.
Most BCF studies are run for only 28 to 31 days, and equilibrium
is assumed to have been reached. But, for a compound such as
methylmercury, with an excretion half-life of about 1000
days, 12 years may be required before an equilibrium is
approximated (Hartung, 1976)., Because of the noise inherent
in the analytical data, there is also a tendency to be overly
hasty in pronouncing that equilibrium values have been achieved
-------
in individual tests when pharmacokinetic data preclude such
a judgment. In addition, it is probable that the exposure
conditions in the laboratory vs. the field differ significantly.
Thus, the laboratory exposures ignore any impact of food webs
in reaching the residue equilibrium concentration. In
addition, in laboratory exposures the pollutant Is usually
administered in a carrier, most commonly acetone, which nay also
contain a surfactant to permit easier solubilization. Such a
method of administration may lead to an exposure consisting
of a combination of dissolved pollutant plus micellar pollutant.
In the field, the exposure would be to a combination of
dissolved pollutant, adsorbed pollutant on micro- and macro-
particulates, and pollutant incorporated in micro- and oacro-
organisms. Clearly the exposure conditions are different,
and the current monitoring procedures in the laboratory and
in the field are not designed to evaluate the different routes
of exposure so that the effective dose can be calculated.
The heavy metal's, excluding organo-metallic compounds,
generally do not bioconcentrate greatly in vertebrates. What-
ever bioconcentration does take place is not associated with
lipid solubility as the driving force, but most commonly
appears to be associated with facilitated transport mechanisms
which have evolved for required divalent cations, aad which
do not appear to be absolutely specific for the required
metals. 'In the case of'bioconcentration of metals by micro-
organisms, it is not always possible to determine whether the
metal'is adsorbed onto the cell surface or whether it is
actually incorporated into the cell. Regardless of the exaot
mechanism of bioconcentratioa of the heavy metals, the usual
laboratory test parameters tend to be siiaplisitic and usually
fail to account for the chemical and physical forms of the
heavy metal in the exposure water. The heavy metals are
usually added as a soluble salt in an acidified stock solution.
As soon as the stock solution is metered into the test aquaria,
the pH and the available ions for coplexation change. While
some of the metal usually remains in Ionic form, the formation
of complex hydroxides, carbonates, and other Insoluble salts,
plus ths formation of chelates with organic trace materials,
can drastically alter the proportion of free heavy metal, and
therefore its availability. These conditions are probably not
representative of environmental conditions, where suspended
solids, different ions and different chelating agents may
predominate. In addition, in the environment most of the ionic,
salt, and chelate concentrations will have approached their
equilibrium state; while in the test situation, precipitates
and chelates are not likely to have reached that state. Again,
as for the organic compounds, the experimental state and the
environmental state are divergent.
- 33 -
-------
Because of limitation in the experimental techniques discussed
above, and because of the problems of duplicating food webs
and other environmental phenomena in the laboratory, the field
data should be examined more closely, and an effort should be
mounted to make optimal use of ail data. At first sight this
might seem to be a very complex undertaking. However, all of
the pharraacokisetic models, even relatively complex models
which consider bieacoumulation via the diet (Pizza and O'Connor
1983), reduce to linear models at or near equilibrium
concentrations. Thus, as the equilibrium state is approached,
the concentrations of xenobiotics found in aquatic organisms
would become proportional to the environmental loading of
that xenobiotio.
In the light of presently available information, more attention
should be paid to the actual residue concentrations in the
aquatic biota. These should ideally be considered as part of
the criterion.and standard-setting process.
* Field_-_d6rived biQOoncentration ooef fiaients,. when
coupled_jwith_.t_an environmental fate model, Q£"
provide a ir.orevT valid site specific method of
calculating.' water quality ^standards.
* Final residue _values need to incorporate site-
specific physical and chemical characteristics
which influence biomagnification.
C r its r ia f o r__Sit e,._, D• e f i n i 11 o-n
The Site-Specific Criteria Modification Process is designed
to allow modification' of national water quality criteria to
local site-specific conditions'. Review of the available
documents and site-specific demonstration studies reveal
that there is less to this process than .meets the eye. In
actual practice, definition of the site appears to consist of
little more t'aan selection of a sampling location from which
to draw water for the site-specific bioassays within the
impact sane of the pollutant in question.
A site must be specified on the basis of environmental
parameters in conjunction with pollutant loadings. As such,
it is unlikely to encompass whole States, but is more
appropriately a stream segment or a portion of a body of
water with relatively uniform characteristics. Boundaries
(site modifications) may also include such things as changes
in sediment or water characteristics (bottom of a large lake
or bottom along a long stretch of river) which contain
-------
organisms that are diurnal or spend part of the life cycle
in solubility sites (e.g., sediment binding of heavy
metals and some organics).
The amount of detail necessary to specify site conditions
depends, in part, upon which procedure for the modification
of the national criteria is selected. Because of the very
nature of a site-specific analysis, the description and
definition of the site will vary with the nature of the site.
The nature of the site definition will also depend very much
on whether the pollutant results from a point source or from
a non-point source.
Alternatively, the* limits of a site could be defined by a
possible influence boundary and by a probable influence
boundary.
The possible influence boundary is the maximum area of
potential effect of aquatic life. The boundary should or
could be delineated by the detection limits of the known and
traceable contaminants from the discharge. The boundary is
here defined by a contaminant concentration to be calculated
or measured. The possible influence boundary constitutes the
farthest reaches of potential impact of the discharge*
On the other hand, the probable influence boundary can be the
minimum area of potential effect. The boundary could be
delineated by the concentration of contaminants known to be
detrimental to aquatic life.
The operational boundaries should be feasibly calculated based
on flow/volume/concentration information from discharge and
receiving waters. The concept of "site boundaries" clusters a
so called "extensible/contractable" template based on
contaminant concentrations, .Areas within and distances between
boundaries are dependent upon receiving water and discharge
characteristics.
The probable influence boundary constitutes the limits of the
area to receive intensive study/monitoring/consideration
regarding protection of aquatic life and its uses.
The operational boundaries need not differ. This concept of
delineating two operational boundaries is intended as a frame-
work for priority and the intensity of testing of the aquatic
life and its uses. The probable influence boundary should
define an area which is to receive the most intensive
monitoring and evaluation.
- 35 -
-------
Again these suggestions apply directly to idealized situations,
i.e., one known discharge with known concentrations, However,
the concept of boundary delineation based on contaminated
concentration (calculated and/or measured) is- in line with the
NPDES Water Quality Guidance Criteria and flexes with discharge
and receiving waters variations.
If site specific criteria are not to be used as enforceable
numbers, the States may use them to develop effluent limits,
water quality standards, etc. However, in the development of
such limits or standards, a state is faced with an array of
factors that has adversely affected earlier attempts to provide
enforceable numbers.
A definition for a "site" states "it must.contain acceptable
quality dilution water upstream from the point of discharge if
the site water will be required for testing" (EPA, 1983, p*5).
The definition does not deal with sites that overlap nor with
sites that extend beyond State boundaries. Acceptable quality
dilution water upstream of a point discharge could be extremely
difficult to obtain especially in water bodies that have
numerous NPDES dischargers*
The General Work Plan presented in the Draft of the Water
Quality Standards Handbook is much too simplistic'and
unrealistic in its approach to selecting sites. If the size
of a stream segment is to make the examination of the site >
practical and that the stream segment should be affected by only
one or two. chemicals, then the general work: plan would exclude
such locations as the Hudson River and the Niagara River.
There are many other problems associated with the criteria to
select sites. Biogeographic zones must be recognized, expecially
as they might be influenced by toxic substances and/or multiple
dischargers. Historical, physical, chemical, and biological
data are not always available for the selected toxic pollutants.
If background information is available, it oust be carefully
scrutinized for its reliability and accuracy. Previously
utilized sampling techniques and analytical methodologies have
not always provided the best data upon which to establish
enforceable numbers.
The work plan, which is to initiate the criteria modification
process at the State level, must have the components of a sound
quality assurance program that would assure a more consistent
implementation of the process throughout the country.
-------
REFERENCES
Anderson, D.M. and F.M. Moral (1978). Copper sensitivity in
Gonyaulax taaarengjj. Limnol, Qceanogr. 23:282-295.
Birge, W.J. and J,A. Black (1982). Statement on surrogate
species cluster concept, In,: Surrogate Species Workshop
Eeport, TR-507-36B. Prepared under project 124? for
Contract No. 68-01-6554. pp. 16-5 to 46-7*
Branson, D.R., G.E, Blau, H.C, Alexander, and W.B. Meely (1975)
Bioconcentration of 2»2f,4,4'-tetrachlQrobiphenyl in
rainbow trout as measured by an accelerated test. Trans.
Am. Fish. Soc. 104:785-792,
Brulanci, K.W. (1.980). Qceanographic distributions of cadmium,
2inc, nickel and copper in the north Pacific. Earth
Planet. Sci. Lett. 47:176-198.
Bruland, K.W., R*F, Franks, G.A. Knauer and J.H. Martin (1979).
Sampling and analytical methods for the determination of
copper, cadmium, zinc and nickel at the nanogram per liter
level in sea water. Anal. Chem, Acta 105:233-245.
Bruiand, K.W., G.A. Knauer and J.H, Martin (1978). Zinc in
northeast Pacific waters. Nature 217^741-743.
Director, S.W., and R.A. Rohrer (1972). Introduction to
Systems Theory. McGraw-Hill, ,New York..
Fitzwater, S.S., G.A. Knauer and J.H. Martin (1982). Metal
contamination and its effects on primary production
measurements. Limnol, Oceanogr. 27:544r-551.
Gibaldi, M. and D. Perrier (1975). Pharmacokinetics. Marcel
Dekker, Inc., Mew York.
Hartung, -R* (1976). Pharmacokinetic approaches to the
evaluation of methylnercury in fish. I.J.C. Workshop on;
Toxicity to Biota of Metal Forms in Natural Water. I.J.C.,
Windsor, Ontario, Canada, pp. 233-248.
Lassiter, R., L.A, Burns, D.M. Cline, H.W. Kolm, H.P. Kollig,
R.'S. Parrish and W.R. Payne' (1981). EXAMS, an exposure
analysis system. U. S, Environmental Protection Agency,
Environmental Systems Branch, Athens, Georgia.
Mesarovic, M.D. and I. Takahara (1975). General Systems Theory;
Mathenatical Foundations. Academic Press, New York.
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Mount, D. (1982). Aquatic surrogates, In; Surrogate Species
Workshop Report, TR-5Q7-36B, prepared under project 1247
for Contract No, 68-01-6554. pp. A6-2 to A6-U.
Neely, W.B. (1980). Chemicals in the Environment* Marcel
Dekker, Inc., New York,
Nurnberg, H.W* (1980). Features of veltaaetric Investigations
on trace metal speciation in seawater and inland waters,
Thalorssia Jugasl, 16: 951-110.
i
Patterson, C.C. and D.M. Settle (1976). The reduction of orders
of magnitude errors in lead analyses of biological materials
and natural waters by evaluating and controlling the extent
and sources of industrial lead contamination introduced
during sample collection and analyses, p. 321 In: Occurance
of trace analysis: Sampling, sample handling, analysis.
U.S. NBS Spec. Publ. 322.
Pizza, J.c. and J.M. O'Connor (1983). PCB dynamics in Hudson
River striped bass. II, Accumulation from dietary sources.
Aquatic Toxiool. 3:313-327.
Sanders, B*, K.D. Jenkins, W,G. Surtda and J.D. Costlow (1983).
Free cuprlc ion activity in sea water; Effects on
metallothionein and growth in crab larve. Science Vol.
222:53-55.
Stumm, W. and P.A, Brauner (1975), Chemical Speciation, In;
Chemical Oceanography. J.P. Riley and G. Skirro (Eds*),
Academic Press. N.Y,. pp. "i73-239.
i'ii
Suncia, W.G. and P.J. Kansen (1979). Chemical speciations of
cooper in river water. In; ACS Symposium Series, No. 93>
Chemical Modeling in Aqueous Systems. E.A. Jeuue (Ed.),
pp. 148-180, ' .
Sunda, W.G., D.W. Engell and R.M, Thuotte (1978). Effect of
chemical speciation on toxicity of cadmium to grass shrimp
paleomonetes puglo: Importance of free cadmium ion. Env,
Sci. Tech, 12:409-^18.
Sunda, W.G, and R.R. Guillard (1976). The relationship between
cupric ion activity and the toxicity of copper to
phytoplankton. J. Mar. Res, 24:511-529.
Surrogate Species Workshop (1982), Workshop Report, TH-5G7-36B.
Prepared under Contract No. 68-01-6554, Work Assignment
No. 6, November 1982,
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U* S. Environmental Protection Agency (1983), Site-Specific Water
Quality Based Approach, 1983-1987. Environmental Research
Laboratory, Duluth, Minn.
U. S, Environmental Protection Agency (1982), Water Quality
Standards Handbook (Draft), Office of Water Regulations and
Standards, Washington, D. C.
Veith, G,D,» D.L. DeFoe, and B.V. Bergstedt (1979). Measuring
and estimating the bioconcentration factor of chemicals in
fish. J. Fish. Res. Bd. Can. 36:104G-lQi|S«
Zadeh, L.A., and C,A. Desoer (1963). Linear System Theory, The
State Space Approach. McGraw-Hill, New York.
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APPENDICES
- 40 -
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APPENDIX 1
SYSTEM THEORY FORMULATION OF THE ENVIRONMENTAL PROTECTION
PROBLEM AND PROTOCOLS IN RELATION TO
SITE SPECIFIC WATER QUALITY CRITERIA
1, THE ENVIRONMENTAL PROTECTION PROBLEM
1.1 Introduction
The EPA's methodology for site specific modification of national stan-
dards for toxicants in aquatic ecosystems gives the impression of an almost
heroic effort to deal with an impossible problem. The gap between the pro-
tocols and the need seems immense, but the problem is so poorly specified that
this judgment is intuitive rather than being based on direct comparison of the
protocols with a clear specification of the need. To evaluate the present
methodology, as well as to assist progress toward more definitive ones,
clearer definition of the fundamental problem is required. The purpose below
is to attempt to formulate the problem in general system theory terms.
The objective of both national and site specific pollutant standards is
to maintain the physical, chemical and biological "integrity" of the environ-
ment. This problem can be framed in terms of general dynamical ("state
space") systems, defined by two expressions:
state trans 1 tion functiont (z,x)
response_(output) function, p: lxX-*Y or y=p(z,x),
where z(t)eZ, x(t)£X and"y(t)sY are inputs, states and outputs, respectively,
and t is time. The transition function is usually approached through a dif-
ferential equation, dx/dt-f(z3x), whose solution is $. The output function is
an algebraic equation.
1.2 State Space Model of Environment
Define environment (ecosystem) I as a set of biological species S;
abiotic substances fi (resources, toxicants, etc.); interactions I, of three
kinds:: sxs, sxJ?; and sxl; inputs Z, and outputs Y;
E - {S, Rf I, I, Y} .
A state space representation of £ is
'\lM, ' ' (1)
where, in general, some set X of state variables is to be formed from the
elements of S,R and I, This expression models the environment £ to be pro-
tected as a general dynamical system.
The general formulation (1) applies to a nonspecific, generalized envi-
ronment. To establish site specific standards snd protocols, specific systems
E = {SjR.IjZjY}, must be considered, i.e., systems defined by specific state
space formulations:
p: Z x {S,R,IM , (2)
Here, SCS, RCS and let. Any refined program for environmental protection
with respect to toxic substances must take site specificity into account.
Therefore, in principle, EPA's site specific program is in the right
direction. The problem is converting principle to practice.
l-i
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1,3 The Environmental Protection Problera
Let p(E) represent the condition of a successfully protected specific
environment, Ess, _This can be defined in diverse ways according to a variety
of criteria. Let p(E) be the complement, representing a damaged or degraded
ecosystem according to the established standards. Similarly, let p(Y) and
p(Y) denote protected and unprotected system outputs, respectively, the means
to assess the condition of E. The environmental protection problem then has
several potential alternative formulations:
1. Find a subset of diagnostic system outputs, Q Y, whose protec^
tion is sufficient to guarantee protection of E:
. (Fib)
The second form is the contrapositive of the first, and both are logical
equivalents. In words, (Fla) states that protection of the chosen subset of
output variables fl is sufficient to guarantee protection of the site specific
environment. For example, if the diagnostic output variables are several
state variables such as a small set of species, tics, say the two species
Pimephales prpmelas (fathead minnow) and Cariodaphnia reticulata (a
cladoceran) , the'n"'Tf la) states that if the effect of some toxicant on these
forms is acceptable by some specified standard, then this is sufficient to
guarantee acceptable water quality with respect to this toxic substance in the
particular water body E. Alternatively, (Fib) denotes that failure to protect
E is sufficient to be reflected in nonprotection of the selected output vari-
ables, If the water quality of E falls below the specified standard, this
will be seen as a toxic effect on the two diagnostic species,
At first glanca, formulation (Fl) seems an adequate basis for the devel-
opment of site specific criteria. However, while it states the consequences
of adequately protecting the output variables (Fla), and of failing to main-
tain acceptable water quality in the environment (Fib), it does not indicate
the consequences of failing 'to protect the diagnostic species, p(0), or of
satisfactorily meeting the water quality standard, p(E). As an example,
prevention p(Q) of mass fish mortality in a water body may be taken as suf-
ficient to guarantee that a toxic substance has not,,. p(E), reached acute
concentrations. The attainment of such concentrations, p(E), would cause mass
mortality, p(Q). However, a fish kill p(D) can also be produced by unrelated
causes, such as anaerobic conditions. Therefore, population mortality is an
insufficient but necessary indicator of acute toxicant level. To compensate
for this, the following formulation is needed.
2- Find a subset of outputs, OCY, whose protection is necessary to
guarantee protection of E;
' (F2a)
- . (F2b)
(F2a) is the converse of (Fla) above, and (F2b) the inverse; again, (F2a) and
(F2b) are logical equivalents. (F2a) states that in order to protect E, p(E),
it is necessary to protect the output variables, p(Q). Maintenance of suit-
able water quality with respect to a toxicant is sufficient1 to guarantee
noninjury up to the specified standard of the diagnostic species of the pre-
vious example, or the latter is necessary to guarantee the former. (F2b)
states that failure to protect the output variables is sufficient to denote
failure in protection of the ecosystem. If the diagnostic species register a
1-2
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toxic response exceeding the defined standard, this means that water quality
has been correspondingly degraded.
Suppose fish mortality in absence of other causes (anoxia, disease,
etc.), |(Q), is sufficient to signal an acute pollution load, p(E), That is,
p(Q)^p(E). Then it is clear that a low toxicant level, p(E), is sufficient
to prevent fish mortality, p(E)^p(0). The fish populations together with
other relevant factorss ^"{populations, disease, oxygenation,,,.}, comprise an
output variable which can form the basis for a necessary condition to assess
environmental damage. That is, failure to protect Q, p(Q), denotes failure to
protect the ecosystem, ,p(0)^p(E), which is the logical equivalent of
p(E)^*p(Q). • Whereas p(Q) above was sufficient but not necessary to denote
environmental damage, p(fi) here is necessary.
Clearly, a site specific protocol upon which to base an approach to
environmental protection should have the necessary, as well as the sufficient,
property. Therefore, the logical basis for environmental protection should be
as follows.
3. Find a subset of outputs, QCY, whose protection is both
necessary and sufficient to guarantee the protection of E:
(F3a)
is the solution of a differential or dif-
ference equation. Attention below will be restricted to the differential
(continuous time) case; the difference (discrete time) case follows a parallel
development.
Thera are, in general, two forms for dx(t)/dt = x(t) = f[z(t), x(t)],
xeX, yeY, zeZ and tsT, where T is a continuous time interval. One is linear,
i(t) = A(t)x(t)+B(t)z(t), x(tQ) = XQ,
a special case where the solution is decomposable into an internal portion due
to state, and an external portion due to input;
x(t) = 4»[z(t). x(t)]
ft A(S)d| t 4
y_ _ j-L . I
= e yo x = J7 e l B(t)z(T)dT .
0
The second is nonlinear, the general case where state and input components of
behavior are inextricably compounded together:
1-3
-------
x(t)=A(t)x(t)+B(t)£[z(t), x(t)], x(tQ)
with solution:
X(t) =
, X(t)]
=e
The expression
(4}
describes change of state on the interval [f,t3» and constitutes a state
transition operator. Behavior on [t ,t] can be modeled either by the Hnear
dynami c_aj_ system ,
(5)
x(t) = A(t) x(t) + B(t) z(t), x(t ) =
y(t) ^ C(t) X(t) + D(t) z(t) , °
,T) B(i)zCt)dt ,
C6a)
with transition function:
x(t) - f[z(t), x(t)]
= *(t,t ) XQ * S
and response function
y(t) - pCz(t), x(t)3
= C(t)*(t,t.)xn + /J C(i)-t(t,t)S(t)2(i)di * D(t) z(t)
00 Q
= yx(t) + yz(t) ;
or by the nonlinear dynaroicaj system:
x(t) = A(t) x(t) * B(t)
• y(t) = C(t) x(t) + D(t)
with transition function;
x(t) - (frtzCt), x(t)]
(6b)
, x(tQ) =
, x(t)] ,
(7)
= *(t,t0) X
,i) 8(1)
, x(t)] di , (8a)
and response function
-------
y(t) = p[z(t), x(t)]
= C(t)
+ 4
O(t)tCzCt), x(t)]
, x(t)]dt
= yx(t) + yzx(t).
(85)
In these equations, x, y and 2, are vectors; x is the initial state
vector; A, B, C and 0 are matrices; and * is a state transition or fundamental
matrix. Further theory regarding these formulations is available in Zadeh and
Oesoer (1963), Director and Rohrer (1972) and Mesarovic and Takahara (1975),
Note that in the linear system, equation (6b), behavior is decomposable into
zaro Input, y , and zero state, y , portions, but In the nonlinear system,
equation (8b), such a separation i^not possible. State and input are always
compounded, y (t), in the function t(z, x)- It is further observed that
these models or dynamical systems, equations (5)-(8), are applicable to any
system; specifically, to the antire ecosystem or environmental system, E,
itself, or to any of its constituents, S or R, in equation (1).
1.5 Behavior Dimensions of
Let E be the set of
set
y
. , ,
of environment
ronments, s the
toxicants. Let
[t jt]CT
j=I,...,s, jCvsS,
materials R. Every
by either equations
of
t
of the
specific
(5)-(6)
same is true for any set or
and R, respectively, SCs
behavior of sny conceivable
entire site specific ecosystem, EsE,
JCS, and Xp-K(t), KCR, .as defined by
these notatibns, the behavioral dynamics
abiotic constituents, singly or in
the Environmental Protection Problem
ll natural or artificial (e.g., laboratory) envi-
all species, and a the set of all resources 4 including
,t] be the nominal (unperturbed) behavior on interval
or environments i=l,...,e, icve£, containing set
species Ss and set k=l,...,r, fcCv£2, of the
ecosystem E, Ess, has behavior dynamics defined
if it is linear, or (7)-(3) if nonlinear. The
element of its biotic or abiotic constituents, S
Therefore, y--,Tt ,tj- denotes the
.-i.Ct ,t] represents dynamics of any
na component behaviors are y,.,,(t),
either equations (65) or (8b). *With
of any system or any of its biotic or
any combination, in any natural or
and RCS.
system; y
subject
setting, and
may be formulated.
.^(t)sZ> tsT, equation
to any set of natural of artificial
to an
artificial
influences
Let Zj.^(t)sZ> tsT, equation (1), be the nominal inputs
environmental system or its constituents or constituent sets, and let
represent perturbation inputs, such as when one or more toxic substances are
introduced or increased. Then, the difference between nominal and perturbed
behviorSj yj-fc(t) and y,»k(t) respectively, measures the response of the
system to its changed eifvironmentj ^Mk(t) - £,-,-L,(t). If the changed
environment represents introduction or increase in Jthe concentration of a
toxic chemical, then y--k(t) - y.-.(t) measures the toxic effect on the system
or subsystem. Let d.1.-! be a vector (or scalar as appropriate) of standards
for substance(s) kc.sj in the presence of species jcs in environment is2,
National standards are denoted when i=£, Crist' anc' S1"'ts SP-C^C standards
when i - E&£, ov-k- The standards are constants, although to handle seasonal
and other time dipindent variability, they can in principle be time functions,
O'-iXt). They may also vary with different uses, uCy, where u is the set of
alt possible uses; thus a. ..(t,u).
considered as constants. J
In subsequent usage the standards will be
1-5
-------
The environmental protection problem can now be formulated in dynamical
system terms:
1. The objective of environmental protection, maintaining the
physical, chemical and biological integrity of the environment, is to minimize
deviations (defined by the standards) between nominal, y-.,(t), and perturbed,
y,,. (t), behavior; 1J*
i j^
such that Ilyi;jk(t)-y1jk(t)[{ S llcr1jk(I >
whare u * \\ denotes vector norms, and the standards a-.-i, are expressed in
terms of effects rather than concentrations to be in unfts compatible with
those of the behavioral responses, y..,k(t) and y.,k(t).
2. The protocol problem W environmental protection is, following
(F3) above, to find a small subset of output variables, Q- ..(t) l|g. -JL Jlo. .,(t)-n^, (t)ll > l|g.., ll
Jijk^-w yukv ^ ijk 44" ijk ijk^w ijk11
These expressions! (9) and (10), then, comprise a theoretical formulation of
the environmental protection problem,
2. ENVIRONMENTAL PROTECTION PROTOCOLS
2,1 Introduction
Notes in (10), that the protocol problem has three elements: (1) finding
a suitable set of output variables, ^--ruC y-nk' (2) finding necessary and
sufficient relationships between the variable 'sets, Q..^ and y-j.-i/, and (3)
through the-behavior of these variables, establishingJtne standards, a, ..,
.such that H«1ik(t)-n,,k(t)li SlU-.JUHp (t)-y (t)tl Silo-. H.These'^e
three distinct^rpbleiiisr. The general protocol development appY-osch of EPA
gives great attention,'however imperfectly, to (3), but virtually ignores (1),
the extrapolation from a restricted set of observables, Q--k(t), to the whole
ecosystem, y.-^Ct)^ and (2), establishing a logical rationing through which to
relate the variable sets Q. ., and y.-.-i.. In the following sections an effort
will be made to examine tnile problems connected with restricted diagnostic
variable sets, and in addition general problems associated with laboratory
based toxicology 'and monitoring. These discussions will provide a basis for
then considering EPA's site specific procedures: recalculation, indicator
species, resident species and heavy metal speciation,
2,2 The .Diagnostic Output Variable Set
2.2.1 Choice of Variables
A fundamental problem,, at the root of all further problems, is to find a
restricted set of variables whose behavior under toxification will reflect,
(F3) ecosystem condition. As the goal of maintaining physical, chemical and
biological integrity involves three classes of variables, all three are
potentially useable in the desired set Q. ... EPA's approach focuses on only
the biotic variables, s, and ignores (except for the specific toxic substances
of interest) the resource set R.
In nature, the biotic variables are interrelated, S x S; they also
interact with the abiotic variables, 5 x Ss and the latter additionally
1-6
-------
interact together, R x s. The result of all these interactions, I, is
integrated system behavior, yESfi("t)- ArW given ecosystem, E&E, with a
restricted list of species, S c I, and physical-chemical variables, RC R,
still has integrated behavior, ypcp(t). This integrated behavior, which may
be lineafj equation (6), or nonlinear, equation (7), involves measurable
attributes at component and subsystem levels, yp^C^). jCvsS} kCvsR, as well
as at the entire system level. Thus, both system level as well as component
and subsystem level variables are available for selecting the diagnostic set
QEik'
J EPA's approach to variable selection ignores ecological considerations,
and focuses narrowly on nonfunctional, taxonomic ones. There are three basic
criteria to consider in selecting a set of output variables:
Criterion 1. Resource variables, kCveR, which reflect ecosystem
function (productivity, respiration, aerobic and anaerobic decomposition,
etc.) should be included in %,•(,» A focus on process outputs will yield
variables which change on short time scales, giving an early warning
capability.
Criterion 2. iiotic variables, jCvaS, which are ecologically
significant in ecosystem structure and function (keystone species, indicator
species, commercially important species, procaryotes, etc,}, should also be
represented in ^C,-L,. Again, emphasis on microbiota, which form the basis for
production and cfccomposition processes, will contribute fast time variables
necessary for early diagnosis,
Criterion 3. Taxonomic properties in the selection of biotic
elements of fV.. should still be employed in an effort to bracket the range of
toxic responses; There are two distinguishable elements of this approach,
which emphasizes purely toxicological, as opposed to ecological,
considerations: (1) The "laboratory white rat" concept. Some small set of
organisms (species) or life stages should always ..be tested in all situations
for comparative standardization. .Pimephalss and Carjgdaphnia are two that
have 'been used for freshwater. Others are possible. The aim is a fixed data
set under standard conditions for i.ntersite comparisions. (2) The "surrogate
species cluster concept". A somewhat larger set of organisms, spanning a wide
range of physiological, biochemical and phylogenetic differences, should also
be tested. 'These organisms for testing should be collected from field
conditions most closely approximating those at the specific sites of interest.
EPA's approach of requiring representation from eight animal familiies
from a selection of phyla is naive, although well motivated to obtain a wide
range of toxic responses, because individual species within a family may
possess quite different toxic responses. An industry bent on not cleaning up
could meet virtually any standard by judicious choice of species, and still
satisfy the taxonomic specifications. Also, specific requirements, such as
that a salmonid fish or penaeid shrimp be represented, have valid ecological
or economic rationales. If trout can tolerate a situation, the ecosystem
which supports them cannot be too greatly perturbed; the trout is an indicator
species. If shrimp are relatively unaffected, the same is true, and in
addition commercial interests will not suffer; shrimp dra an economic, as well
as indicator, species. In selecting higher organisms, or those in which
exposure to toxicants is indirect (e.g., as in food chain concentration), it
should be remembered that response times would be expected to ba
correspondingly slowed,
Recommendation 1. SPA should carefully study the problem of choosing
diagnostic vairable sets, il.... These sets should:
: JK
1-7
-------
needs
1. Embrace ecological as well as toxico logical considerations,
2. Include abiotic as well as biotic variables,
3, Meet both short term (acute) and long term (chronic) diagnostic
4, Include invariant
possible national sites, and
elements for standardization across all
5. Include variant elements to achieve site specificity.
2.2.2 Variable Sufficiency and Necessity
The logical problems inherent in protocol development, i.e., (Fl) vs.
(F2) in Section 1.3, are difficult to solve in actual applications. The
desirad formulation is (F3), expressed operationally in expressions (10a) and
(lOb), But how are these relationships between the diagnositc variables,
£1. .^(t)j and the entire set of field variables, y»-k(t), to be established?
Present SPA protocols ignore this altogether, assunlmg that whatever is true
for Q.. ..(t) also holds for y. ..(t). The fallacy here is readily apparent; for
exampii, it was observed above' that any desired response could be obtained by
simply adjusting the member variables, e.g., one species instead of another in
a given family. Both sufficiency and necessity must be considered.
Sufficiency. The two logically equivalent forms of this problem
are, from (Fl) , ......
(lla)
(lib)
The key to establishing (lla) is determining that (lib) 'holds. For example,
suppose data obtained from observations made during T
-------
The latter, (i4b), is the operative form for environmental protection pur-
poses, but to establish it the equivalent form (14a) must be implemented. In
the same man.ier as to achieve (12b) above, I.e. measuring all or roost of the
variables y.-j (14a) is demonstrated on T|laljkl] (15b)
is valid, establishing (14b), the necessary condition. This can then be used
in future monitoring to detect system perturbations based on perturbations in
the diagnostic variables,
lio C16)
allowing p[Q, .^(T1 )] to be sufficient to establish future failure,
pCy.- jiXT-' )], io protect the ecosystem. This gives the required necessary
condition, and (13) and (16) together comprise sufficient and necessary conj
ditions, (F3), to protect an entire system based on the monitoring of a few
variables.
Recommendat_Ton_2. EPA should develop protocols and methods to establish
(13) and (16) through field or microcosm experiments based on relationships,
respectively, (12b) and (15a). Then, by monitoring the set, fi-,-^, of selected
diagnostic variables with established necessary and sufficient relations to
the larger set, y^b, of system output variables, the status of ecosystems
with respect to toxicant standards > cr,.., can be determined on a continuing
basis, J
2.2.3 Determination of Standards
How should the values, a. .^ , for different toxicants under different
conditions be set? The notation -Tor standards, o-^, is efficient in allowing
different combinations of conditions and toxic suostances to be represented,
as follows:
1, Conditions. Heretofore, ieE has been used to index a specific
ecosystem, Es£. Each specific ecosystem has a wide range of physical corr
ditions in it over a period of time (temperatures, pH values, salinities,
etc.). The index i can now be refined to refer to a specific set of more
microscopic conditions defining macroscopic E. Thus, iC vea refers to such a
set of conditions rather than grossly to the whole ecosystem which has them as
attributes.
2, Biota. The index jCves refers to a particular combination of
species; subsequent usage is unchanged from that previously established,
3. Substances. Toxic materials may occur in polluted waters singly
or in different combinations. Tha index kCv*5 has previously denoted any
possible combination of resource variables, including complex mixtures. This
usage will be continued.
Thus, cr. .. refers to ecological conditions iCves in which biota jCves
live utilizing, beneficially or harmfully, materials kCvefi.
1-9
-------
Suppose conditions differ, denoted, say, by i and i1, i.i'CvsE, Then
°iik ~ CTi'ik or g'ik * 0i'ik' ciePandl"ni uP°n the effects of the changed condi-
tions on rSTe toxit responses of system output variables. Similarly, under
different species combinations, j and j1, where j.j'Cvss, 0..^ = ^1-.-ii> °r
or. ., 7* a'*'\f are possible. Finally, under different resource sertings'^k and
k1* where1 ^kJrC ves, cr, .. = cr. .,, or a. -k * a. .. , are possible. In principle,
then, each of the stamSards HJ. .. , ci-fL, crV-1., o. , .,., cr,,,.,, CT,,..( and
cirk, are all potentially diffeV&t. n Jk 1J K 1 J K 1JR ] JK
^ For illustration* with fixed i and j, suppose k denotes one set of subj
stances, including toxicant A by itself, whereas k' represents the same re-
source set, except that now toxicant B is also present in addition to A, If A
and 8 interact, synergistically or antagonistically, then clearly a- -^ *
CT-.,S and therefore ' ^
II 5JJk(t) - a1jkft)l| S Hc^yly^Ct) - y,.jk(t)ll s He. .Jl (17.)
51jk,(t) - a1jk.Ct)H S||a.Jklii^1jk,Ct) - y1jkl(t)II S//a1jk,J/(l7b)
and
are two different things, a,,, and a. .^ , represent two different standards,
Therefore, , since toxic rispones may vary under different ecosystem con-
ditions, i, species compositions, j, and resource combinations, k, standards
should be set in contexts as close to those of the system of interest as
possible. EPA has been partially responsive to this dictum by recognizing
that different mixes of toxic materials may produce different toxicological
results, and by correcting for experimental vs. site water differences through
water effect ratios calculated in their site specific protocols.
Recommendation 3. EPA should develop site specific standards,
under conditions i, species compositions j, and mixes of substances k appr
mating as closely as possible the ranges of these factors met in the subject
ecosystem. Protocols designed to compensate for variability met under field
conditions, including possible temr"'>ral (e.g., seasonal) variability, should
be carefully thought out as a bas^ for procedures that are realistic and
practicable.
One of the -major problems in developing such protocols is the transition
from laboratory toxicology data to field situations,
2.3 Laboratory Based Toxicology
In Section 2.2,1 it was recommended that sets of diagnostic variables,
n».,, include not only a few species selected for taxonomic spread, but in
addition other variables based on ecological considerations. In general,
however, toxicological tests are performed on selected species in specific
life stages; therefore, they apply to only part of what should be a fuller set
of diagnostic output variables. This part is subject to problems of
extrapolating from experimental to field, conditions,
2.3,1 Diagnostic Variable Dynamics
Just as the output variables, y-.^eY, of a system are based on a
corresponding set, x. ..sX, of state variables [equation (3)], so the
restricted set of dragnostic variables, fl-ui has underlying it a
corresponding restricted set of state variables, x- >sX. If these state
variables behave linearly on a time interval T = [t J,t], then equation (5)
applies, yielding for the transition function of the restricted set:
1-10
-------
and for the response function
n1jk(t) * c1jk(t) *
+
Equation (18a) corresponds to (6a), and (18b) to (6b); x — i/O is the initial
condition of the rsstrictid set of state variables. Trre notations of equa-
tions (18) may be shortened to:
XiJR(t) = *ijk(t,t0)xijk(t0) * JT *.jk(t,t) B1jk(t)i1jk(t) dt , (19a)
a1Jk(t) = Ci^t)*.^,^..^ + ojjk(t) Zlj(
and
Z,jk• The considerations for bioassays performed
on nonlinear variables are therefore not the same as where linear variables
are concerned.
2.3.2 Linearity vs. Nonlinearity in Toxicity Testing
Let the response of a set of diagnostic output variables on T in a
controlled acute or chronic laboratory bioassay be, for the control, either
(I9b) (linear) or (2Ib) (nonlinear), and for the treatment:
1-11
-------
= cf jk(t)*ljk xijk(t0) + o. jk(t) z1jh(t)
+ jy'lv^lj^''0 Bijk(T5t1Jk(T)dt: (19c)
in the linear case, and
C210
in the nonlinear case. A
In (19b) vs (19C), and (21b) vs. (21c), if Xiik(tQ) * *iik(t ) and
z.-te(i) = Z--K(T), then the environmental conditions'* are the same between
control and treated variables and it is initial state that is manipulated,
For example, if temperature, food, toxicant concentraticnss etc, are the same,
and organism densities or species compositions, etc. are different, then this
corresponds to a state manipulation in the experiment. If X-j^CO = X-^-Ct )
and z.-jfCt) * Z.-^CT), then it is the exogenous environment ? temps ritu re,
toxicant, etc.) thtft, is altered, with initial state held constant. Finally,
if both X^CO # X11k(t ) and 2,^(1) # z^^Ct), then both state and input
variables nave been variea betweenjthe experftirental controls and treatments.
Recommendation 4. Regardless of the linearity or nonlinearity of test
systems in toxicology experiments, great care must be taken to manipulate only
those state or input variables which are the subject of testing. Inadvertent
variations in nontest variables will contribute spurious components to the
observed behavior, confounding or masking effects of the intended treatment,
and making statistical discrimination of true results more difficult. The
frequent death of control organisms in field testing performed by JRB and
associates serves as a warning example. Control of test conditions by careful
choice of subject pop.ulations, adequate replication, adherence to experimental
design, etc. must be rigorous, "Quick and dirty" methodologies are forbidden
as next to worthless,
, The toxic response of test variables, reported, e.g., as a set of
values, is the difference between treatment and control behaviors. In t
linear case:
jk(t)
. (22a)
For the nonlinear case,
-------
x1Jk(t)]dt
x kzx. (22b)
These art the basic expressions for any toxic response observed under
conditions i, with species mixture j, and chemical conditions k. The linear
response is decomposable Into portions due to initial state and input,
M). .. (t) and AQ..fc(t)xl respectively, whereas the nonlinear response always
carries with it rarms/ Ml- • , (t) , in which state and input components are
inseparable. This is the fUftfa.rnem.a1 distinction between linear and nonlinear
systems.
In the linear case, the state portion, Aft. ^(t) , captures the inherent
response of the tast system to the experimental treatment. This is intrinsic,
and can be carried over as a property of the test organism(s) or other
variables from one exposure situation to another (where i» j and k are, of
course, the same). The tnput portion of the toxic response, fiQ- i( (t)7»
represents the consequences of transferring the system to exposure cortdftiofts
(with fixed i, j and k) where the driving exogenous inputs, z(t), differ. In
the nonlinear case, the endogenous and environmental components of the
observed toxic response cannot be separated, there will always be behavioral
terms in the response of the form AQ-.^(t) , In a subtle philosophical way,
linear thinking can be established al th2^ root cause of the experimental
practice of placing test objects in a variety of environmental (input)
circumstances in laboratory or field seeking to determine the role of
environmental factors in dynamic behavior. For many, or most, biological
systems, however, this is a role which cannot be isolated from the role of
state.
2.3.3 Stationarity vs. Monstationarity
Based on the resultSj ££l. -,(t), teT, of bioassays, toxicant standards,
0. -. , are arrived at through a' "Variety of procedures and protocols. That is,
for a set of toxicants and diagnostic variables, equation (lOa) is
established, where
f(^ijk(t)fU)!a.jkl|. (23a)
The standards are time invariant although, as indicated in Section 1.5, they
could be time varying, a. ^(t), tsT, if necessary:
i JK
1-13
-------
(Z3b)
• . j N I J *>
In expressions (23), £0, -k(t) are as defined in (22). These standards are
than to be transferred TO different sites, i'ss. j'sS, and k!£5, at future
times, t'eT'>T, for the purpose formulated in expression (10) of protecting
the subject environment, i.e., of assuring that
!i^n.tk,(t')jUffa.jk//. (24)
There is a tacit assumption in this practice, probably based in linear thought
which emphasizes intrinsic properties of organisms such as integrity through
time, that time translation presents no problem, but it may,
Dynamical systems may be stationary (time invariant) or nonstaticnary
(time varying). A stationary system is one which, begun in^ the same initial
state at two different times, x(t ) = x(t '). and subjected to the same
subsequent stimuli, z[t ,t] = z[t , t'J, where [t tt] = T and [t ' t1] = T1
>T, will behave identically, y[t ;tj = y[t ',t'] & the two different times.
Otherwise, y[t >t] * y[t *,t']; a system is nonstationary. The existing EPA
protocols do indicate the need to account for seasonal variability, and other
time dependent sources of variation in toxic responses. The stationary
property is essential to establish in order to move from bioassay to field
without considering the time offset. Otherwise, care must be taken to
establish that observations ara made in comparable time periods in the life
cycles of both the subject organisms and the eocsystercs they occupy.
Strictly, this is difficult to achieve, and the following recommendation is a
statement of principle more than practice:
Recommendation 5. Stationary dynamics of subject systems, linear or
nonlinear, cannot be assumed. Most natural systems are periodically time
varying, however, with circadian, lunar or seasonal cycles in their behavior,
EPA should strive to establish that their diagnostic output variables are
stationary, but failing this, or if they are clearly nonstationary, then
temporal controls should be' exercised. Protocols to achieve this should be
developed and applied to assure that only-observations made during comparable
phases of natural cycles are compared. Minimally, for example, summer data
should only be compared to summer data, low flow data to low flow data, etc.
Awareness of the importance of the stationarity problem is the first step 'in
developing practical solutions to- it, which EPA must develop as part of its
site specific guidelines,
2.4 Monitoring
Environmental monitoring is the means of determining continued health,
IUyijk(t)ll £ l!c?1jk|| , (lOa)
or degradation,
of subject ecosystems based on establishing (24) or not through time. A
spatial element is also present, and can be introduced by modifying equations
(6) and (8). With sefs-,, s2, $,}, where s,, s2 and s, are the three
dimensions of physical space, (o) ana (7) become'
1-14
-------
8x1jk(S|t)/»t - A1
8xiJk(Slt)/8s - A1jkCs,t)2x1jk(s,t) * 8,Jk(S>t)2z1jk(s,t) (25)
for the spatially as well as temporally linear dynamical system, and
9x.jk(5,t)/St = A1Jk(s,t)1 x.jk(S,t) + Bijk(s,t)rC[z1jkCs,t),x1JkC5,t],
8xijk(stt)/8S = Aijk(s,t)2x.jk(sst) * B.Jk(sst)Clz1jk(s(t)5x1jkCs}t]2 (26)
yijk(s,t) = C1jk(Sjt)xijk(s,t)
x,jk(s,t)]2
for the spatially and temporally nonlinear system. Other combinations include
mixtures of spatial linearity and nonlinearity in the three spatial
dimensions, for both temporally linear and nonlinear systems.
Monitoring may be conducted for several purposes, including (1) baseline
surveys, (2) impact detection, (3) compliance monitoring, (4) establishment of
causality, and (5) prediction. It is always limited to a restricted set of
diagnostic variables, n,.,(s,t)C y1--k(s,t)I whose necessary and sufficient
relationship, (F3), to tni full set of^ ecosystem variables, y--k(s,t), raust be
assured: J
i Ib^Cs.t)!!. (27)
Note here that a spatial as well as the temporal element has been introduced
into the standards, i.e., cr.-^(s,t), for generality. This allows the option
of perfflitting lowered standards [in general, higher values of the variables of
tf.,,(s.t)l in the plume from an -outfall, or in downstream segments, if
dWrred.
2.4.1 Baseline Monitoring
To establish nominal baseline conditions, some set of monitoring
parameters, 0. ^Cy • ^ is chosen. The variable 0. -k(s5t) represents a vector
of thase parameters -"treasured in 1, 2 or 3-dimensicmal space, s, and discrete
or continuous time t. Nominal conditions Q,-k(s,t) are established by
measurement of the parameter set overi appropriate "-"intervals of space and time.
The principal issues in this baseline monitoring are (1) choice of parameters
(Section 2.2,1), (2) determination that they are necessary and sufficient to
represent ecosystem behavior (Section 2.2.2), (3) spatial and temporal design
of sampling,and (4) data 'assembly, analysis and presentation. Baseline
conditions represent the starting point for all other forms of monitoring.
2,4,2 Impact Detection
In previous sections, toxic effects have been formulated as deviations
from nominal, e.g., 'equations (22), and these deviations compared to standards
expressed not as ;oncentrations but, for dimensional consistency [see text ff.
equation (9)], as effects. Two kinds of effects are chronic and acute. The
latter may always be said to reflect standards expressed as concentrations.
In chronic effects, however, concentration standards may never be exceeded yet
long term, cumulative effects may occur. Examples include lowered dissolved
1-15
-------
oxygen levels, impaired fecundity of organisms, stunted growth, anomalous age
class distributions, high incidence of tumors, parasites or disease, etc. To
monitor for .these effects, some time and/or space integrated measure of
deviational behavior may be required, e.g.
P[^ijk(s,t)] = H/t/sM)ijk(s,t) ds dtil. (23)
In impact detection monitoring, the subject system is considered perturbed
(unprotected, F3b) when ?(£&...) > Ijcr,-,(s,t)//, and unperturbed (protected,
F3a) otherwise, P(AQ-...) I Her--, (s ,t)|f.J The main issue in impact monitoring,
in addition to thos^ identirraa above for the baseline case, is dafining
suitable standards, cr..,(s,t), that will reflect either acute or chronic
effects. In the TattePcase, where impacts are cumulative and concentration
based standards are nevar exceeded instantaneously or incrementally, integral
measures such as (28) may have to be devised and affects based variables
included in the standards set,
//a-.k(sft)/I or P[An,fk(s,t)3 > f/cf.,k(stt)//, from its historically nominal
condition soon after an anthropogenrc activity is initiated in an area. Is
the new activity responsible for the observed changes, or are these merely
part of long term variability in nominal dynamics? Or more complexly, which
ones of a set of human activities in an area are causing the deleterious
changes that monitoring reveals, and which are not? How can causality be
assessed? The means to do this is built into the principles implicit in
Recommendations 1-4 above. By the considerations outlined therein, a
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necessary and sufficient relationship is established between suspected cause
and observed effect. Then, if the cause is present, the effect will be seen
In monitoring data (sufficient), and if the cause is absent, the effect will
not be observed (necessary).
2,4.5 Monitoring for Prediction
Predictive monitoring is 'also a technically difficult problem because it
requires an offset in time. Observations made in earlier time, 0-.,(s,t),
t£Tk(s,t(), t^sf'. In
terms of conditional logic, prediction requries that "^
or
(30a)
and
(23b)
or
P[AQijkts,t)3
(30b)
Necessary and sufficient conditions (1) are based on Recommendation 5,
establishment of the stationary property, and conditions (2) are based on
adequacy of the relationship between system variables y-^ and diagnostic
variables Q.-,.-^ as developed in Recommendations 1-4. Strict adherance to the
principles Inherent in these recommendations should make a predictive
monitoring methodology theoretically possible, but discovering the protocols
required to gain this strict adherence is no easy technical matter,
2,4 The EPA Protocols
This section will endeivor to briefly examine SPA's approaches
environmental protection against chemical toxicants in context of
foregoing theoretical specification of the basic problem.
tg
the
2-4,1 The National Guidelines
The national criteria are global
in their intant to deal with all
ecological conditions, i-E, biological species, j=s, and resources, kCvss (see
Section 1.5). That is, they are designed to protect all aquatic environments:
1-17
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where cr en is the national standard for the k'th toxicant. The impossibility
of achieving such a global solution represented by (31), without making the
standards unrealistically stringent, rightly leads to tha site specific
approach. The theory laid down here at least verifies that, in principle, the
site specific approach is the correct one.
Tha national standards a fail to implement (31) effectively for a
variety of reasons. In attempting to protect all environments, they in effect
protect no environments with significant problems. They deviate strongly from
all the recommendations provided above;
Recommendation 1. The national standards are based solely on
toxicology data; ecological considerations are ignored. Biotic variables only
are considered; fast-time abiotic ones are needed. An effort is made to
account for both chronic and acute effects, and to aquire invariant
information on representative sets of (animal) species- Site specific 'choices
of species are, of course, ignored.
Recommendation 2, No effort is made to establish necessity or
sufficiency of toxicity information in the national data set.
Recommendation 3. By definition, the national standards are non-
site specific,
Recommendation 4. The stringent control requirements of laboratory
toxicology experiments have probably, in most cases, not bean met.
Recommendation 5. Stationary dynamics of ecological systems are
assumed by the fact that the stationarity problem is ignored.
Recommendation 6. The national guidelines, which are to be used in
lieu of site specific information, should be reviewed and improved with
respect to the principles inherent in the preceding recommendations which
apply,
2,4.2 Site Specific Rationale .
Site specific guidelines are designed to introduce local considerations
into the process of deriving standards. As previously formulated, expression
(9), the objective is.
nayfjk(t)'l sl/^^H, ' (9)
where iCveE, jCveS and kCvsS- • In this, It is recognized (1) that the
combination j of species at a site (with characteristics i and resources k)
may be more or 'less sensitive than those used in the national criteria data
set, or (2) that the water quality characteristics, i and k, at that site may
alter the toxicity of the species collection j to the chemical of interest In
k. Site specific criteria ere designed to deal, singly and jointly, with
these conditions, and in addition, to account for seasonal variations in water
quality.
Formulation (9) exactly reflects this rationale. EPA'5 definition of
"site" (e.g., EPA 1982, p.3-4) is adequately captured by the concepts itvea,
jOves and kC vss as 'unique combinations of, respectively, ecological
conditions, species, and resources. However, the assumption (EPA 1982, p.
3-6) that species sensitivities and toxicological effects derived frara
laboratory tests will be similar to those in the field is at variance with
fundamental considerations in the role of environmental factors in system
dynamics. There is little in theory to justify such an assumption (Section
2.3); if it were true, then by the same rationale the results from any
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particular toxicology experiment in the laboratory or field could be
extrapolated to the national level, and there would be no need for site
specific guidelines. To the contrary, "biological integrity" is frequently
judged to prevail in situations where toxic concentrations exceed standards,
and biodamage may occur under conditions where concentrations chronically
never exceed standards (EPA 1SS2, p. 3-7).
Four procedures have been developed to implement the site specific
rationale. They are the recalculation, indicator species, resident species
and heavy metal speciation procedures,
2.4.3 Recalculation Procedure
This procedure is designed to account for differences in sensitivities of
resident species, jcves, to a toxic chemical for biological reasons.
"Resident species" are defined, acceptably, as those which normally occur at a
sits during a time interval T which spans seasonal variability (EPA IS82, p.
3-12). Extinct species at the site are not . included, nor do long term
variations in species lists appear to be taken into account.
The recalculation procedure permits eliminating families required to
establish the national acute toxicity standards. Defects in the strictly
taxonotnic approach to selecting diagnostic biota, acknowledged in the
sensitivity of final ecute values to family selections (EPA 19823 p. 3-21),
have already been pointed out (Section 2.2.1). The recalculation procedure,
being tied to this approach, shares this fundamental flaw.
In addition, there are specific problems. A sits specific acute
standard, 0". ., ^ } (the final acute value, FAV), is calculated after deleting
nonresident '•species from the' list of those used to determine the national
standard, aff. , and meeting minimum data set requirements. This site specific
standard isi"1fnen arbitrarily adjusted for conservativeness/, vto obtain a site
specific maximum instantaneous concentration, ^ ••,•(, '2* This is
scientifically baseless, although justified by the1 ^Generally unrefined
character of the approach. A final chronic value', cr--,^ » is obtained by
applying a laboratory based acute-chronic ratio to the FAV. This violates
several basic principles (Sections 2.2.3 and 2.3) pertaining to the
extrapolation to field situations from laboratory data.
Recommendation 7. The recalculation procedure is inadequate, both
•basically and "Tn terms of technical details, to account for species based
sensitivity differences between site specific toxicity responses and responses
from which national standards are derived. The problem should be restudiad by
EPA, and a scientifically better grounded protocol (Section 2-2.1) for
selecting biotic diagnostic variables formulated. 'Many of the specific
considerations developed in the recalculation procedure can be carried forward
for improved elaboration in a more definitive methodology,
2,4.4 Indicator Species Procedure
This method is used when site water quality affects the toxicity of a
compound. That is a- ., ^ a., .^,, where i' £ i denotes ecological factors such
as pH, hardness, aTkalinifey, carbon dioxide equilibrium relationships,
salinity, etc., and k'^k denotes resource factors such as organic solutes,
inorganic and organic colloids, and suspended particles- The method assumes
no difference in response of resident biota from those species in the national
data base. It uses a simple multiplier, the water affect ratio, to correct
for differences between site water and laboratory test water. The water
effect ratio is calculated using resident species at the site, or "acceptable"
(EPA 1982, p. 3-22) indicator or surrogate species. As in the recalculation
1-19
c
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(a)
procedure, a final acute value, 0".,:,/ , is calculated and Xhen conservatively
adjusted to/a.maximum instan-taneots concentration, a4l-, V2. Final chronic
values, Q".-,/ , are computed either from the FAV, or bh'foftic toxicity testing
with any (resident or nonresident) fish and invertebrate species.
The indicator species procedure is positive in recognizing that
ecological, 1C E, and resource, kC#, factors may modify the toxicity
responses or bioaccumulation characteristics of site specific resident
species, jCs (Section 2,2,3). However, in effect, this recognition itself
negates the narrow toxicology based philosophy of EPA which otherwise
generally ignores ecological considerations (e.g.*, Section 2.2,1), Specific
criticisms of the indicator species procedure are: (1) the assumption, in
order to use it, that no species response differences exist between resident
and national data base species, which is unrealistic; (2) "acceptability11 for
nonresident indicator or surrogate test species is not defined; (3)
apparently, any two species of a fish and an invertebrate may be usad in
testing for chronic toxicity; and (4) in an effort to be practical, the
procedure is in final analysis too simplistic.
Recommendation 8- The indicator species procedure, as it presently
exists, is inadequate as a method. However, many of the principles inherent
in it should be retained in a totally redesigned approach to incorporating
ecological considerations more fundamentally into the EPA site specific
protocols, in accordance with Recommendations 1-3 (Section 2.2).
2.4.5 Resident Species Procedure
This procedure is to be used when thare is reason tc suspect that both
species and water quality differences may cause differences in toxicity or
bioavailability of a chemical, i.e., a. - ?= a,,,,,,, where i ? i' and k = '<'
denote environmental differences, and j i j1 denotes species differences. The
procedure calls for applying both the recalculation procedure to account for
species differences, and the- indicator species procedure to account for watar
differences,
Recoromendation 9. The resident species procedure is philosophically
consistent with previous recommendations which emphasize the need to
incorporate both ecological and toxicologies! desiderata into a site specific
methodology. While both the recalculation and indicator species are
individally philosophically dafective, together they combine to remove tnis
criticism, and basically only technical flaws remain. Therefore, the resident
species procedure should be retained as the cornerstone of an interim site
specific methodology, while EPA movas forward to develop definitive procedures
that are both philosophically and technically matched, in realistic pragmatic
ways, to the difficult requirements of ths problem.
2,4,6 Heavy Metal Speciation Procedure
The national standards for metals are axpressad as total recoverable
metal based on laboratory data on total recoverable, or acid extractable metal
concentrations. Metals exist in a variety of forms, each with specific
toxicolcgical characteristics, i.e., ^^-t/i * CT~'k> w^are k' == k denotes two
different forms of a metallic element in quastiotu In setting site specific
standards for methods, either the indicator or resident species procedures may
be used to modify the national standards.
Recofflmendation_lQ- Based on the general inadequacy of the indicator
species procedure by itself, the resident species procedure should be employed
as an interim methodology to set site specific standards for heavy metals.
However, a more definitive metals protocol should ba developed, in accordance
with the principles outlined in this report-.
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3. SUMMARY AND CONCLUSIONS
The problem of setting water quality standards for toxic substances is
one of the most difficult applied environmental problems possible because (1)
it intersects head-on biological and environmental diversity and variability,
and (2) requires a refined integration of all this complexity mapped into a
quantitative "standard" for each toxic material. The problem pushes
environmental science well beyond the current state-of-the-art.
As presented to this committee, the site specific problem was poorly
specified. Underlying philosophical and logical issues had not been
systematically examined as a basis for the pragmatic methodologies that had to
be developed and thus took precedence. As a result, the existing procedures
are deeply flawed and in need of revision. The fundamental wisdom to move
from national to site specific standards is unchallenged, however, and is
endorsed as correct and urgently needed.
With the need to bring the problem into better philosophical and logical
focus, a preliminary attempt has been made here to provide a general systems
theory specification that can underly future methodological development- Ten
recommendations have been made which encompass the principles exposed by this
theoretical development;
1. Diagnostic variables should be carefully chosen to include both
biotic and abiotic ecosystem properties which reflect ecological as well as
toxicological considerations;
2. Necessary and sufficient relationships should ba established
between the restricted set of diagnostic variables and the larger set of all
relevant ecological variables;
3. Standards should be site specific, and matched as closely as
possible to the conditions and species at each site;
4. Laboratory toxicology tasting must be conducted under carefully
specified and stringently controlled conditions;
5» Protocols should take account of temporal variability in
toxicant effects,
6, National guidelines, if they are to continue to be used in lieu
of site specific information, should be improved in accordance with the
preceding recommendations;
7. The'recalculation procedure should not ba used by itself;
B, Neither should the indicator species procedure be used by
itself;
9. The resident species procedure should ba used as an interim
methodology until better ones have been developed; and
10. The heavy metal speciation procedure should be based on the
resident species procedure until improved methodologies are developed,
Finallyj a general recommendation based on all the preceding material may
be offered in conclusion:
SUMMARY RECOMMENDATION. EPA Should (1) further develop better
specification, in theoretical terms, 'of the environmental protection [Section
1 and expression (9)] and protocol [expression (10) and Section 2] problems,
building on the start made here, and (2) employ the contiuually improving, and
possibly alternative, formulations of these problems to develop better site
specific methodologies that are pragmatic, consistent with emerging
principles, and conformable with both ecological and toxicosogical criteria.
-------
LITERATURE CITED
Director, S.W. , and R.A. Rohrer. 1972. Introduction to systems theory.
McGraw-Hill, New York.
EPA. 1982. Water quality standards handbook (draft), U.S. Environmental
Protocol Agency, October 1982, Washington, O.C.
Lassiter, R., L.A. Burns, O.M. Cline, H.W. Holm, H.P. Kollig, R,S. Parrisb and
W.R. Payne. 1381. EXAMS, an exposure analysis modeling system. U.S.
Environmental Protection Agency, Environmental System Branch, Athens,
Georgia.
Mesarovic, M.O, and Y. Takahara. 1975. General systems theory; mathematical
foundations. Academic Press,, New York.
Zadeh, L.A., and C.A. Oesoer, I'9S3. Linear system theory, the state soaca
approach. McGraw-Hill, New York.
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APPENDIX 2
EVALUATION OF CASE HISTORIES IN R3LATIQM TO
FIELD VERIFICATION OF PROPOSED GUIDELINES
field testing for the development of site-specific criteria was
completed at 19 sites in 16 States. Sites, pollutant sources,
and types of pollutants were selected by EPA regional offices
and the States. Most of the field work was contracted out to
JRB and Associates, with the exception of studies in California
related to the use of 2,1-D esters in forest silviculture.
The work was developed to test a wide variety of locations,
types of aquatic habitats, and chemical pollutants. These
included pesticides, heavy tnetals, ammonia, and chlorine fro?.
wastewater treatment plants.
Field studies were bassd on the Guidelines for Deriving Site-
Specific Water Quality Criteria for the Protection of Aquatic
Lifa and Its Uses. The case histories did contain much useful
information, 'out as a whole the Committee found all of thera to
be inadequate to support site-specific aodifioations of the
criteria.
The lack of specificity for the development of field studies,
including such iteas as collection and treatment of samples,
appropriate selection of test species and more specific
information concerning the selection-of actual sites to be
sampled and the conditions under which the sampling should be
done led to socie problems with the design and conduct of field
studies. Most of the studies involved the testing of the
effects of a single pollutant from a point source of pollution.
One field test, completed .in California, was of a non-point
source of pollution, ths aerial application of the herbicide
2,4-1? esters,
The initial selection of sites was dictated by the location of
the point source of pollution and by the order of entry of
other sources of pollution in addition to the potential for
dilution of the initial sources. Generally, sites were
selected upstream from the sources of pollution, at or near
the point source, and in additional areas in the recovery-
zones. The protocol was to sample water from upstream sites,
at the point source, and then at various locations in the
plume and in the recovery zones. Upstream water was used to
test resident species to develop water quality ratios for the
specific pollutants studied. The selection of sites seemed a
matter of convenience rather than a deliberate choice to sake
locations comparable in slope, habitat characteristics, and
2-1
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other water quality measurements. In some of the studies,
the selection of comparable sites may have been difficult
because bottom sediments, aquatic planes, and characteristics
of the stream or river were altered by the source of pollution.
This was true for those point sources that included heavy
sediment loads which altered the character of the stream or
river bed. In some instances, there might have been a better
choice of more comparable sites for comparing water quality
and species composition.
The selection of species to be tested presumably was based on
the available information OH resident species and in some
cases the initial collections of organisms from the site itself
Some of the studies actually used species collected from the
site, while others utilized animals from other sites, such as
rivers, lakes, ponds, and, in some instances, fish from
hatcheries wera used in the pollutant testing for water quallty
ratics. It would seem most appropriate to use organisms
collected in the actual waters where the testing was to be
done; this would insure a more natural response to the test
pollutant in both static and flow through systems. Response
of organisms taker, from other waters and from hatcheries would
undoubtedly lead to greater variance in response to site water
and an additional variation to the added pollutant based on
prior exposures to water qualities of unknown characteristics.
the purpose of the site-specific water quality criteria would
seem to be related to the actual response of resident species,
and more effort should have been made to test actual residents
from the body of water being used as a field site. If suf-
ficient numbers of organisms were not available at the
appropriate time or were not convenient to being collected, a
greater effort should have been made to collect organisms from
similar bodies of water nearby; it would hava been preferable
to use species from the field rather than hatchery-reared
organisms»
The development of the field testing p.rotocol should have been
carefully monitored in terms of the quality of the water being
used for the static and flow through tests. Measurements of
water quality at the intake source should have been compared to
that, in the tanks at the time of testing. Collection, pumping,
and storage of water, even for short periods of time, could
have altered these parameters to where they may have influenced
the response of the organisms to the pollutant being tested.
In some of the studies, high losses of control animals did
indicate that water quality characteristics were not
sufficiently beneficial to the continued existence of the
animals being tested. These problems in some of the studies
negated the results of the pollutant test.
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Surveys of organisms at the various sites was done by a
variety of methods, and the efficiency of these techniques was
not always taken into consideration. In some instances, the
use of shockers or seines would produce varied results based
on water quality characteristics as well as total flow and
velocity. Development of diversity indices would not be useful
if variation in sampling techniques biased the collections,
In one instance, high flow levels precluded adequate surveys,
yet the field work continued despite adverse conditions.
Quality control in the analytical work seemed to be appro-
priate, but the addition of the toxic metals to waters and
their subsequent assay may have to be revised in the light of
new information related to metal speciation. Actual tasting
of species in laboratory, reconstituted, and flow through
waters varied. In sons cases, loading factors varied; in some
tests, species were mixed in flew through waters; in others
species were tested separately; in ether cases water was
aerated; and in other instances it was not disturbed. This
may have been related to the pollutant being tested in tersis
of volatility; but, in total, the test conditions could have
been better standardized.
Prior exposures to toxic substances for resident species may
present a problem in tasting programs. Body burdens of various
substances could result in resistance or greater susceptibility
to the teat pollutant as a result of synergism or alteration in.
physiological conditions. Handling stress, particularly of
hatchery fish, might also alter susceptibility to the test
substances. Test organisms that display resistsnoe should be
testec in laboratory water to deteroine if water effects ratios
are causing the altered effect of the pollutant, or whether
developed resistance may have occurred in the resident species.
In some tests the sources of species came from all different
sites, from lakes rather than stream systems and from hatcheries
rather than the field. rrt'ater effects ratios for invertebrates
and vertebrates that are diametrically opposed should be
discussed and perhaps analysed further. It would seem that
actual residue data from the resident species would be valuable
in assessing the results from laboratory exposures.
All of the studies were of short duration, presumably as a
result of time and cost restrictions imposed on the field
testing program. Some prior development of background materials
for the various sites would have been useful in terms of stream
gradients, habitat types, stream, flow characteristics,
a'/ailability of test species from the site, and the potential
added sources of pollutants at both upstream and downstream
2-3
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locations* Historical data on flow rates might have led to
siore opportune times to sample and perhaps a more equitable
evaluation of the effects of the pollutant load on the resident
aquatic species. The use of resident species taken from the
recovery zone may be questionable because the potential for
some prior exposure would be increased. Physical factors an waters free from the test pollutant. More attention
should be given to the prior description of the test site; and
the actual water quality, habit types, flew conditions, and
pollutants should be available prior to the actual site selection
and field testing. This would allow for the development of a
roere efficient and desirable testing prograa both in time and
performance. Additions of pollutants, particularly the
heavy metals, should be done according to the latest methodology .
Field testing reports should also contain some review of
potential decisions concerning pollutant loads, and they should
also recommend a plan for sonitoriug the site following any
change in the site-specific standards for a toxic subscanae.
3 on Ca.3eHistorias
The following pertains mainly to the JRB reports or contracted
studies, but the principles, nevertheless, apply all around.
There are two outstanding aspects involving philosophy/
approach/principles that are generally applicable. They cannot
be solved by toxicologies! tests or is-provsment of bioassay or
chemical analytical techniques.
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The first is best expressed on page Ul of the Mill Creek,
Clinton, Iowa draft report. The last paragraph cakes the
point that the acuts and chronic toxic tests ara not telling
the story of the effects upon organisms, A quote^-frcm
context to be sure--in mid-paragraph states this ccgeatly,
"Total taxa, biomass, ehlorphyil, and diversity showed a
continual decline 'at downstream station which was not
consistent with measured toxicant concentrations." From
this, together with what we have learned about che inaccuracy
of both the derived and experimental determination of toxic
criteria, it is probable that the pursuit of these sores
of data-alone are a loss of effort and money and have solved
no problems, nor is continued pursuit of this coarse bound
to'solve the problems at hand.
be measured by LCjQ's alone. The amount of data required
or type of understanding needed is really no more or less
than that which would be required for the present techniques,
ideally, What is required is a new direction in, cr approach
to, thinking as it concerns ecosystems by'the authorities
enforcing the Clean Water Act.
The second aspect is closely related to this and involves
an attitude toward sampling. Almost all of the contractors
fail back on "Standard Methods1' for their techniques in
sampling and also in the selection of locations for sampling.
Then 'they appear to be aaazed when these methods do not work
for their particular situation. Often, also, location of
stations and time of sampling are nov carefully done with
rsspect to knowledge of the site. The best ail around
approach to such problems is to decice what it is one needs
to know, the feasibility of getting this information, how
the site (systera) in question can best reveal this infor-
mation, and what sorts of techniques can fa a st_ be employed,
standard methods notwithstanding. This approach should be
taken first and foremost afte_r aetersining what ecosystess
are involved, what is already known about t;heffi» and what
sore needs to be known to decide on an assay action. Only a
systematic approach can reveal uoeable answers.
The following pertain to more specific issues;
Mill Creek.,.. Clinton , ^ Iowa
p.9. Setting up artificial periphyton substrates was a good
idea, but why were they floated in mid-water? Why were they
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not put on the bottom or sides of the creek where the
periphyton occur in greater abundance?
p „ 9 . If there is a question of dissolved oxygen vs. chemical
or biochemical oxygen demand in various locations, why were
diurnal and turbulence tests not run to detersine the oxygen
source?
The use of perip'nyton as an index of growth stimulation
or toxicity, i.e., chemical influence on the ecology, is a
good one, but the investigators need to have a better
under-standing of both the ecology of these types of organises
and how the systems interact.
S__R i vgr_, _Mars rial 1 to wn_, _ Iowa
p. 2-7. The perip'nyfcon methodology needs rethinking, also it
should be realized that some of these organisms are not or.ly
indicators but species of importance in their effects upon
other organisms. This is a point that many of the investi-
gations sees to bypass.
p. 2-S. When there is a distinct peculiarity in response,
e.g., mayfly to ammonia toxici'tys one doesn't just say that
the LCgo's could not be calculated; one tries to find ar.
explanation for the behavior1 (e.g+, possible internal pK
change or some binding of NHq),
p, 2-6, 2.2.3- One fish collection may not necessarily
characterize an area.
£ . 2 . U , Physical characteristics of the river shcuid reveal
arsas of concentration of form's (.e.g., where some stage of
early development occurs).
pp.. 3™^- A coarse quantitative net, possibly like a plankton
net, can be used for capture' and, if intelligently designed,
can be used at various depths, at least for relative number o'
organisms determinations,
Sel3sr ' sCreek
___ __ __^^ _
p. 2-5. The floating macro-plants should have been sampled
quantitatively* The substratum furnished may have been
the principal source of organisms,
p. 2-6, The turbidicefcer does not give the 'oest estimate of
visibility, light penetration, or supended particles.
Newer techniques are no more trouble or expense and far
more revealing of usable information.
2-5
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The contractors a_r_e_ using a good set of indices whan applied
with logic (top of the page),
p. 4-1, The characteristics discussed in the first paragraph
also probably influence distribution of toxic substances
physically and chemically by substrate binding.
Also, a different approach to alkalinity anior.s is needed
since there are low pK'sj also the hardness should not be
calculated as CaCCj under these conditions but rather as
meq. It should be determined what are the important anions
in the water at these pH's.
Ths contractors show different taxa at different stations.
What are the effects of ambient and toxic conditions on the
distribution of indigenous forms?
Since "his is an important farm area, what tasting has bean
cone on ?Qij, soil quality, and other non-point source
intermittent changes?
(Linear.^) Salt Creek.,. LinQol_n_,_Nebraska
By their own admission, the non-point sources are important
contaminaters. If so, break-through concentrations plus
buildups may be found frequently in several local areas with
probable effects en wells and groundwater. A regime of
sampling to accommodate non-point sources should be
established. . , •
There should be a whole new. approach to ben^hic organism
study methods4 Organises occur where they are, which may
be on the bottom, 1'n suspension , temporarily in suspension.
dirunally active, etc., and sampling methods should be based
on these occurrences, not en what bottom sampling techniques
are available in "standard methods," which do not apply to
all types of physical situations,
F1 i n_t JjJ. j g r _, Me a r F1 i r. t. M i c ji j. y a n
Here, sotna attempt has been ctake to use other dimensions,
such as time and seasonal!ty, but this has not been well
thought out, e.g., seasonality is not told by the month, but
rather by the change in condiiions; and time effects are
often really what happens in the darkness, under different
sun angles, and'under cloud cover.
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Hutch in 3 o n, M i n n s s c t a
In general, there needs tc be improvement in field sampling
techniques and possible mathematical relationships of the
behavior of organisms to field characteristics, e.g., speed
of currents, particle suspension physics, bottom types, and
the seasonal changes in these. Plankton net type of instream
capture should also be considered.
There should also be concern with a variety of non-point
source distributed substances, since this is an agricultural
area,
p. 3^8, If nutrients are an important factor in this area,
standard asicroplant culture assays should be instituted using
both indigenous species and EPA-accspted microoiants in stock
culture.
Boggy and Skeleton Creeks, £nid, Qklahogia
This survey .should definitely have included diurnal studies
on both dissolved oxygen and ether factors. They also have
a non-point source problea, since this is farmland.
a
M_ingo Cre.sk, Tulsa, Oklahoma
p.2-10.' Samples were taken from only the
p.3-2. Hardness and alkalinity study may have bean very
important here, especially at night.
p.3-12. This was a clear demonstration of physical factors
influencing population types and trophic levels. It is toe
bad that the study was not pursued a little further, as it
might have given' aore insight into heavy metal distribution,
into charaicai species and chemical activity. Seascnalicy is
also very isaportant with regard to stream concentration,
Cali fo rn i a F is h a n d Gam e
What is ths.ncrzal equilibrium in natural waters of 234-D
esters and acid and what are the factors controlling them?
Cali for n.la ' £ t a ts _ W a t e r R g s o u r c e s C or.tr o 1 Scare! (2,-r-D esters^
p.9. Thar* is'obviously a, p h y sTo! o g i c a I difference between
rainbows and steelheads. What is this difference fue to?
What are ths conditions of 2,4~D ester hydrolysis?
p.17; end of paragraph 1. Is the Committee to understand
that a sampling device that is automatic or activate
shore cannot be developed and be cheaper in the long
that the approach currently used?
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?.31» Again this points toward the need for methods in non-
point source contamination detection,
p,32, last paragraph. This points up the need for survey
planning to get the kind of results that are useful
and to u$8 pooled resources.
These people have severe non-point-source-in-rescte-areas
problems. Therefore, special considerations should be giver,
for subsurface flow regimes, soil surveys, etc., at key
locations along with either automatic or composite (pooled)
sample collecting gear. Much of this can be cone at low
cost,
?u 11 g_an . ',i&._snihgt_on (Depar ttnent__of Civil Sn£inserj.r.g)
p. 12. More needs to be known about the physiological behavior
of the sculoin. How was the natural water filtered before usa?
p. 13 and • 5.. Either better handling techniques need to be
found for ephemeric,-; or work should just ba done on stoaeflies.
Possibly, collection of the organisms should be dona at a
stage when they might be more hardy.
p.20, This shows the potential value of behavior as an index
of toxic'ity in both the fisid and laboratory (Drift of
ephensroptera out of streams dosed with copper—see also
near top cf p.21 , )
p,i. There are indications of concentration of algae.
p.ii, (Of the abstract from Funk.et al») The indications
here sre that physiological clearance' tests of anifiials show
the importance of function (clearance) in ths assay of nxgher
organisms. This is not even suggested in any of the other
surveys,
Camp, i)res_s6r, ami MoK-as, Hamburg, Mew Jersey
p,2. Why was dilution watar not obtained above tha A.™es
plant? What about runoff from tha highway?
p,4. Last paragraph. How does raising, effluent, and river
level vary seasonally?
p.3. If coefficients of variance were run, there say havg been
differences between lab and site water,
P.9. The answer to the posed problems might be in the seasonal
change in stream characteristics.
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p. 10, last paragraph. It is not clear whethsr no further
tests are recoaunended because of expense. The fata aspect of
the contaminant may be stream mitigation or concentration i.:*.
the stream wail or sediments until there is a break-through
to the stream horizontally or to groundwater vertically.
Carolina Mirror
With the data obtained on the UT and associated streams,
one would have thought that acre work might also have been
done on sediments and on physical characteristics of the
stream shape and flow. Also, seasonal input would be necessar;
to know whether or not the carefully described characteristics
change throughout the year,
Hempstead Wastewater Treatment Plant,, Maryland
Seasonality, rainfall, pH influence on the slTdiffier.ts (binding
of ammonia) show the need for sctne checks thoughout the year.
The same is true at Bufcrd, Georgia, and in the latter place
as well, the binding of NH-? to waste particles and carbani.io
completing can change the degree of tcxieity at least or, micro-
organisms ,
Finally, the Committee would like to recommend two papers
that bear strongly on the types of assays we have beer, reading
One deals with bioconcentration by rainbow trout and the
other with the important and definite distribution of fishes
in habitat gradients along stream lengths.
Oliver, Barry G, and Arthur J . Niirni (1983)- B_ip con c_e n t r a t i on
of__chlorQ_bj,nzeji5g froa water by_ rainbow trout; Correlatio:
with partition coefficients and environmsntal^resicues.
Science and Technology 17(5);237-291.
Schiosser, Isaac J. (1983). F i sh_c o $3 u n i t y 31 r u c t u re _ a r. d_
f u_a_o t i o n a 1 o n g t w o ha b i t a t irg r adj. 5 n t s _i n a he a d va t a r _s t r a a r
Ecol. Honogr , " 52^'T- 395-4"l 4.
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