DRAFT WHOLE EFFLUENT TOXICITY (WET) IMPLEMENTATION STRATEGY
FIVE KEY COMPONENTS OF DRAFT WET IMPLEMENTATION STRATEGY:
I. National WET Outreach and Training Program
II. Continue to Encourage the Development of Water Quality
Criteria and Standards Based on Good Science
III. Write Better NPDES Permits for WET
IV. Enforcement
V. Fund Research Needs
INTRODUCTION:
The U.S. Environmental Protection Agency, (EPA), developed this
draft WET Implementation Strategy in response to the findings
and recommendations from the September 1995 Society of Environmental
Toxicology and Chemistry (SETAC) WET Pellston Workshop, the discussions
at the September 1996 WET Stakeholder's Implementation Meeting,
and the recommendations of EPA Regional and Headquarters staff.
For purposes of this strategy, stakeholders are defined to include
all interested parties including regulators, the regulated community,
nonprofit organizations and the general public. It is important
to note here that this Strategy is part of the EPA's commitment
to undertake a "finetuning" and "midcourse"
correction to an existing program that the Agency believes is
scientifically sound. Recently, the scientific soundness of the
WET program was further validated at the 1995 SETAC WET Pellston
Workshop. The WET Pellston Workshop was made up of independent
scientists from government, academia, and representatives from
the regulated community who met to discuss the scientific basis
for the WET testing program. In addition, the Pellston Workshop's
proceedings included two implementation recommendations which
were further discussed at the recent September 1996 WET Stakeholder's
Implementation meeting. The two implementation issues were training
and outreach.
The draft WET Implementation Strategy represents a "big picture"
framework and is an outgrowth of the concerns that the stakeholders
expressed with respect to implementation of whole effluent and
ambient toxicity in the water quality standards (WQS) program,
the National Pollutant Discharge Elimination System (NPDES) permitting
and enforcement programs, and research which the EPA believes
should be conducted to further support and benefit the implementation
of WET program. As such, this draft WET Implementation Strategy
outlines the Agency's thoughts on how to improve the implementation
of the WET program. The EPA will be looking to the stakeholders
for both comments and cooperation to fill in the implementation
strategy and finetuning details.
Although many issues were raised at the WET Implementation meeting,
four key areas were identified as priorities and the EPA has added
the area of research. Many valuable options and issues were raised
at the September 1996 meeting and, therefore, the EPA opted to
focus on those issues which best represent the common concerns
expressed by most of the WET Implementation meeting participants.
The EPA has prioritized the five issue areas and plans to address
them in a fashion such that the most practical and optimal improvements
to the existing WET program can be realized first. The prioritization
decision was based, in part, on Agency resources. Not all initiatives
can start right away; some will require long term efforts. Some
initiatives are tied to other projects and, therefore, they will
need to be addressed at a later date. Also, the EPA's resources
are declining which means it may be necessary for the EPA to look
to partnerships to complete some initiatives.
The draft WET Implementation Strategy will continue to evolve
as the EPA considers the feedback received at the September 1996
meeting as well as the comments from stakeholders reviewing this
draft strategy. Once we review all the comments, the Office of
Water will be looking for assistance from stakeholders to finalize
the National WET Implementation Strategy. During the process of
developing a National WET Implementation Strategy, U.S. EPA Regional
Offices, States, or American Indian Tribes who have National Pollutant
Discharge Elimination System (NPDES) Program authorization or
section 401 certification authority will continue implementing
their existing WET control programs. This is because the EPA believes
that the WET Program is scientifically sound and any changes,
or implementation recommendations which result from the EPA's
National WET Implementation Strategy are "finetuning"
to an existing program.
The draft strategy outlines the five key areas listed above, it
breaks out each key area into issue statements, and it lists proposals
or options under each issue statement. In more detail, the five
key areas and respective draft issue/proposal statements are as
follows:
I. NATIONAL WET OUTREACH AND TRAINING PROGRAM
ISSUE: The EPA training for the WET program has decreased
substantially over the past five to six years. This coupled with
continual turnover in staff at both the State and Federal levels,
as well as decreasing resources, has resulted in new staff not
being adequately trained, and the WET program not being implemented
consistently throughout the nation.
TO ADDRESS THIS ISSUE, THE EPA PROPOSES TO:
Continue funding to the SETAC Foundation to form independent
Toxicity Expert Panel(s) that will provide additional expertise
on issues such as conducting Toxicity Reduction Evaluations (TREs)
and other technical issues, exclusive of policy and regulation.
Continue supporting to the national WET training program to provide
training on WET first to permitting authorities, second to permittees,
and later to all other stakeholders to foster better understanding
of the overall program and to promote working partnerships. Educate
partners in the permitting process on technical terminology to
ensure a common language, increase the familiarity with permitting
models and derive appropriate limits (e.g., the EPA statistical
approach).
Include the topic of NPDES permit enforcement as an element of
EPA NPDES permit writers and WET training courses, and encourage
the EPA, State, and Tribal enforcement staff to attend.
Include a discussion on WET and the application of narrative versus
numeric criteria in the existing EPA Standards Academy training.
At all staff levels, work to achieve better coordination between
program areas and staff competency in water quality standards
and NPDES programs by fostering cross program training and position
"swapping" opportunities.
II. CONTINUE TO ENCOURAGE THE DEVELOPMENT OF WATER QUALITY
CRITERIA & STANDARDS BASED ON GOOD SCIENCE
ISSUE: There is a need to match the sensitivity of toxicity
criteria (e.g., tests methods, species, endpoints) with the gradation
of aquatic life use designation the criteria are intended to protect.
TO ADDRESS THIS ISSUE, THE EPA PROPOSES TO:
Provide national guidance recommending that the permitting
authorities implement appropriate designated beneficial uses and
where possible sitespecific criteria.
Begin to reevaluate the safety margins (e.g., critical low flows)
used for establishing WET requirements to increase the confidence
in the limits developed to predict receiving stream impacts. For
example, exposureresponse data (e.g., concentrationresponse
and repetitive testing over time) may be routinely developed in
WET testing to allow more accurate extrapolation to receiving
stream responses.
Develop methodologies to support the development of sitespecific
toxicity criteria. For example, WET testing may yield different
ratios of LC1/LC50 for different site waters without changing
the intended level of protection. Therefore, developing sitespecific
toxicity criteria for WET testing parallels the intent of the
sitespecific procedures for chemical criteria. WET may also
be subject to the same concerns observed with site water chemistry
variability and, therefore, must be considered in the water effects
ratio (WER) development.
Provide additional guidance, technical transfer and/or resources
to regulators for developing use attainability analyses (UAAs).
The EPA will provide written guidance to both the permitting authorities
and the regulated community on the minimum recommended elements
of a UAA and onhow and when UAAs should be conducted.
Develop guidance and/or regulatory language to address the appropriate
and necessary elements that comprise a narrative WET standard
so that it may be easily translated and implemented into the NPDES
permitting program. This guidance may include key elements such
as the application of mixing zones; selection of test methods;
and the frequency of testing. These elements could then be included
in a State or Tribe's water quality standards implementation plan.
Encourage upfront participation of the regulated community
in the water quality standards development process.
Use the existing mechanism of the Advanced Notice of Proposed
Rulemaking (ANPRM) to evaluate the policy of independent application
(IA). As part of this process, consider the minimum elements of
a weight of evidence approach including, for example, use of reference
sites for biological assessments and high quality, rich data.
III. WRITE BETTER NPDES PERMITS FOR WET
ISSUE: NPDES permits need to be written clearly so that if
permit violations occur, the violation is valid and solidly backed
by defensible data in the permit documentation. As such, NPDES
permits should be written in such a way that: (1) the best available
WET data is used to establish limitations; (2) collection of WET
data is required prior to permit reissuance; and (3) sufficient
data is collected to make the "reasonable potential"
(RP) determination.
More specifically, WET requirements in an NPDES permit need to
be well documented and written clearly so that the permit protects
water quality, is defensible, and is enforceable. NPDES permits
are developed and implemented based on: (1) WQS grounded in good
science, and (2) well thought out permitting options with appropriate
input from the public and stakeholders.
One of the areas where inconsistency in the application of WET
in NPDES permits may occur is in the interpretation of 40 CFR
122.44(d)(1)(v). This regulation states that where there is a
narrative criterion for toxicity, and where a finding of RP has
been made, permits must include a WET limit unless the permitting
authority can demonstrate that chemical specific limits are sufficient
to attain and maintain applicable narrative State water quality
standards (WQS). These regulations have not been implemented consistently
across the country.
Application of reasonable potential for WET is another area where
inconsistency may be occurring within the NPDES program. This
may be caused by some permitting authorities not fully exercising
existing flexibility in the NPDES RP regulations. However, when
permitting authorities exercise the existing regulatory flexibility
for RP, they must do so consistently. The EPA is prepared to reexamine
the RP permitting issue so that all parties start from the same
reference point or clearly agree on how RP is defined with respect
to the NPDES program. There is, however, a trade off between flexibility
and consistency that needs to be understood by everyone. The trade
off is that if flexibility is promoted, then consistency may be
sacrificed and vice versa.
The two topic areas identified in the previous paragraphs are
further discussed below in two sections (Reasonable Potential,
and Issues Other Than Reasonable Potential).
TO SPECIFICALLY ADDRESS THE REASONABLE POTENTIAL ISSUE, THE
EPA PROPOSES TO:
Reemphasize that permitting authorities use the EPA
document, "Technical Support Document for Water Qualitybased
Toxics Control" (TSD), ( EPA/505/290001). This
document contains recommendations for determining RP for receiving
water toxicity, using a statistical approach.
Redefine and clarify RP to characterize the effluent toxicity
more completely, including considerations of both effluent and
analytic variability during permit development. This clarification
on the definition of RP could require an amendment to the current
regulations or could be done through guidance.
Implement a "stepwise approach" to permitting
which would standardize a practice of collecting sufficient, high
quality WET data before or during the NPDES permit development
process. This would result in the final permit being based on
high quality data rather than no data (or estimates). By taking
this stepwise approach, permitting authorities could require
better data collection and anticipate problems before they occur,
thereby shifting the emphasis of the WET program to permit development
and monitoring.
Include monitoring requirements in the NPDES permit which provide
for adequate chemical screening to determine the toxic potential
of known or suspect chemical constituents, and compare to recent
WET data (less than two years old) to assess the potential for
WET impacts.
Where RP is demonstrated for the screened chemical compounds,
the permit writer must then develop appropriate permit limits
for those compounds. Using this approach, WET testing can serve
as an additional and necessary information source to the chemical
specific analyses, for providing insight to toxic effects caused
by unknown or unsuspected compounds, or the synergistic/additive
effects of compounds in the effluent. In these situations, WET
limits must be incorporated into NPDES permits when WET test data
demonstrates an RP for toxicity.
Develop WET permit limits to accurately reflect the designated
beneficial uses for the receiving water system. In other words,
WET limits should be included after thorough examination of a
water body's designated uses and the reasonable potential to impair
the uses. This approach, however, is dependent upon use designations
being sufficiently defined. It may be approached through the WET
limit directly, or by further refinement of test method requirements
required in the permit.
For example, if the use designation is generic, a "boiler
plate" WET limit (e.g., as "aquatic life" boiler
plate: 0.3 Tua end of pipe and 1 TUc at the edge of the mixing
zone using EPA methods and standard test species) may be appropriate.
If however, the use is designated without much detail (e.g., as
"aquatic life: boiler plate 0.3 TUa end of pipe and 1 TUc
at the edge of the mixing zone using EPA methods and standard
test species) the use designation does not give enough information
to go beyond this. However, where the use designation provides
more detail, for instance"limited warm water habitat"
and there is no State numerical criterion, a refined WET testing
regime using alternative species (e.g., to match the designated
use) or end points may be appropriate. This approach to permitting
can be emphasized and explained further in training provided by
the Agency.In addition, to further reflect refined designated
uses, the focus of the"Step wise permitting approach"
should include permit specifications which support the most appropriate
but also most protective WET requirements. For example, the selection
of the appropriate dilution water (e.g., laboratorially produced
or commercially available se lected control water) or the option
of using the receiving water as diluent water (to determine the
receiving stream's possible mitigating chemically interactive
or toxic effects) is important when running WET tests. The main
objective, however, when making test material selections is to
ensure at a minimum that the tests' results are defensible and
supportive of determining whether the permit conditions or limits
have been met. Therefore, approaches to permitting such as including
specific requirements for the careful selection of diluent water
or the appropriate species can lend a more realistic evaluation
of the actual toxicity impacts to the receiving stream.
Recommend permitting authorities provide more detailed information
to the permittee on requirements within the fact sheet and the
permit. In other words, communicate clearly in the permit the
circumstances under which sequences of steps will be triggered
when a permit limit or condition is violated. Provide the permittees
with guidance on approaches for addressing toxicity such as initiating
a simplified approach to conducting a TRE (e.g., best management
practices [BMPs]).
Include in the development of the "stepwise permitting
approach" a requirement for a monitoring trigger when a limit
is exceeded (e.g., conducting accelerated testing, implementing
BMPs, substitution of chemicals or conducting a Toxicity Identification
Evaluation [TIE]).
TO ADDRESS ISSUES OTHER THAN REASONABLE POTENTIAL, THE EPA
PROPOSES TO:
Provide additional guidance to stakeholders through Office
Director memos regarding appropriate interpretation of EPA test
methods (e.g., April 1996 memo from Tudor Davies, OST).
Provide guidance to stakeholders on the appropriate examination
of effluent flow and monitoring data in order to establish a realistic
link of exposure assumptions to permit development. Encourage
permitting authorities to use dynamic modeling and mixing zones
when practical and possible.
Provide detailed guidance to stakeholders regarding necessary
elements when developing a toxicity monitoring requirement or
limit (e.g., cite test species and test method; number of dilutions
required, steps to address permit limit exceedances; and define
the permit limits both in terms of a multiple sample (e.g., average
monthly limit) and in terms of a maximum sample (e.g., maximum
daily limit).
Develop a national workgroup to: (1) investigate the issue of
proper use and prevention of toxic effects to the waters of the
U.S. for registered chemicals used for agricultural, industrial
or other public use (e.g., diazinon and chlorpyrifos); and (2)
reemphasize that the chemical producers and commercial users
of registered chemicals are accountable for toxic impacts to the
waters of the U.S. for these same chemicals. In addition, the
national workgroup will work with permitting authorities to interpret
their narrative standards to address possible toxic impacts due
to industrial process substitutes and other industrial raw materials
associated with the registered chemicals.
Investigate the approaches to accounting for test method variability
in deriving the permit limit or determining the need for a limit.
Reemphasize through guidance the difference between what
constitutes an NPDES permit limit requirement and what is a monitoring
requirement. If a permit contains monitoring requirements, the
permit may also contain required procedural steps which may be
triggered when toxicity in the effluent or receiving water is
identified through monitoring. When this occurs, the permit should
provide or reference the required procedural steps to be taken
to address the suspected toxicity identified (e.g., TREs).
Stress the importance of the DMR language which requires permittees
to report effluent data "to the best of their knowledge"
and clarify or explain the differences between test method accuracy
and reporting accuracy.
IV. ENFORCEMENT
ISSUES: Many of the members of the regulated community and
some permitting authorities do not seem to be aware of the current
EPA enforcement guidance and policy in the area of WET. EPA enforcement
documents which include guidance on WET are:
1989: Office of Water (OW) issued the "Whole Effluent Toxicity
Basic Permitting Principles and Enforcement Strategy." This
document was also included in the appendix of the 1991 "Technical
Support Document for Water QualityBased Toxics Control."
The strategy outlines WET compliance tracking and review, inspections,
use of TREs, and enforcement.
1989: WET was added to the EPA's Enforcement Management System
guidance, including recommended enforcement responses for different
types of WET violations.
1995: Clean Water Act Settlement Penalty Policy (EPA)
1995: OW and the Office of Regulatory Enforcement issued a joint
memorandum (August 14, 1995) clarifying existing National policy
with regard to single exceedances of WET limits and inconclusive
TREs.
TO ADDRESS THIS ISSUE, THE EPA PROPOSES TO:
Incorporate the information on the EPA's policy and guidance
on WET enforcement and include it in Agency training courses and
outreach efforts. Regional, State, and Tribal staff need training
on the use of inspections to verify permittees' biomonitoring
capabilities.
Dedicate an electronic bulletin board or "Home Page"
to provide easy access to the permitting authorities and the regulated
community on all available information, guidance and policies
concerning the WET program.
ISSUE: Many stakeholders questioned whether it is appropriate
for a single exceedance of a WET requirement to be considered
a violation and subject to enforcement action.
TO ADDRESS THIS ISSUE, THE EPA PROPOSES TO:
Reiterate current EPA guidance and policies that any violation
of an NPDES permit is a violation of the CWA for which the owner
or operator is strictly liable and for which the EPA recommends
a timely and appropriate enforcement response. However, the nature
of the response varies depending on the facts surrounding the
violation.
The EPA recommends permitting authority exercise timely and appropriate
action for any permit violation. Enforcement discretion is used
to determine an appropriate enforcement response, taking into
account all factors, including: magnitude, frequency, and duration
of the violation; human health or environmental impact; and compliance
history of thefacility.
Any violation of a WET requirement is of concern and should receive
immediate review by enforcement personnel. This does not mean
that every WET violation will result in a formal enforcement action.
The permittee has ample opportunity to challenge the appropriateness
of any permit requirements during the permit development process.
A permittee is precluded from challenging the appropriateness
of his permit requirements during an enforcement action.
The EPA generally recommends an escalating response to continuing
violations of any parameter. The Enforcement Management System
(EMS) does not recommend that the initial response to a single
violation of any limitcausing no known harmbe
a formal action with a penalty. There may be c ircumstances, such
as a threat to public hea lth or a fish kill, where a strong initial
response would be warranted. However, the typical response to
a first violation is a phone call or notice of violation, escalating
to administrative or civil judicial action for more serious or
continuing violations. For WET, an appropriate initial response
to a single exceedance could be issuance of a 308 letter or an
Administrative Order to require accelerated testing with a TRE
trigger, if not already required by the permit.
Section 505(a) of the Clean Water Act allows citizens to take
a civil action for ongoing or intermittent violations of any standard
or limit under the Act.
ISSUE: Stakeholders asked whether permittees that are involved
in an inconclusive TRE are entitled to technical assistance and
enforcement relief.
TO ADDRESS THIS ISSUE, THE EPA PROPOSES TO:
Reemphasize the EPA's 1989 WET permitting and enforcement
strategy which states that, in the unusual cases where the permittee
has implemented an exhaustive TRE, applied appropriate influent
and effluent controls, and maintained continued compliance with
all other permit requirements but is still unable to identify
and control the cause of toxicity in order to achieve compliance,
special technical evaluation may be warranted and civil penalty
relief granted. The EPA's policy of enforcement discretion allows
consideration of "good faith" efforts to comply in determining
an appropriate enforcement response and in assessing penalties.
However, the permittee should be aware that any mitigation applied
does not negate the original violation or excuse any future violations
of WET requirements.
The NPDES permitting authority should verify whether the TRE was
exhaustive, and provide compliance assistance when appropriate,
in the course of compliance evaluation and performance audit inspections.
The NPDES permitting authority should also consider whether to
issue a 308 letter to verify that the TRE protocol was followed.If
the permittee has conducted the TRE in good faithi.e.,
in accordance with the permit or enforcement order requirementsand
still is unable to identify and control the underlying cause of
toxicity in order to attain compliance, for example, due to unregulated
sources of pollutants, the NPDES permitting authority should consider
whether to require the permittee to implement an environmental
public awareness of a pollution prevention program through an
Administrative Order.
If the permittee fails to implement the TRE in good faith and
come into compliance as required, the permittee would be subject
to enforcement action for failure to implement the TRE as well
as for the underlying WET limit violations.
Provide technical assistance to permitting authorities and the
regulated community via the SETAC Foundation's panel of national
experts on various technical areas (i.e., conducting TREs).
V. FUND RESEARCH NEEDS
ISSUE: In 1995, the EPA initiated a reexamination of
the science of the WET program by cosponsoring, with the
SETAC Foundation and other stakeholders, the WET Pellston Workshop.
Although the Pellston workshop confirmed that the existing WET
program is scientifically sound, the proceedings from the meeting
did list several recommendations for "finetuning"
the existing program. The findings and recommendations for the
WET Pellston Workshop can be found in "Whole Effluent Toxicity
Testing: An Evaluation of Methods and Prediction of Receiving
System Impacts," (SETAC Press, 1996). While the EPA acknowledges
that all the research recommended from the Pellston Workshop would
be beneficial to all concerned, the Agency proposes to focus its
research in those areas that support the implementation of the
WET program.
TO ADDRESS THIS ISSUE, THE EPA PROPOSES TO CONDUCT STUDIES
AND RESEARCH
IN THE FOLLOWING AREAS:
Initiate studies to evaluate improvements for the statistical
analysis of toxicity test data. Fund the need to enhance the current
statistical approaches for both hypothesis testing and point estimate
models and approaches to quantify the confidence around test endpoints
to improve interpretation of WET test results.
Investigate ways to develop test precision criteria to limit test
variability. Investigate how to use discrete test method variability
data in the development of a permit limit along with effluent
variability.
Develop requirements for the evaluation of new test methods (e.g.,
additional test species) and modifications to approved test methods
(e.g., different test temperatures).
Continue evaluating the feasibility of a more integrated bioassessment
program, including the use of biological assessments, WET test
results, and chemical analyses in a weightofevidence
decisionmaking process to assess receiving system impacts
caused by effluents. Develop the minimum data quantity and quality
requirements, including the necessary reference site comparisons,
needed in order to apply a weight of evidence approach.
Develop a methodology for development of sitespecific toxicity
criteria. WET testing, even if the appropriate test is selected,
can yield different ratios of LC1/LC50 for different site waters
without changing the intended level of protection. Therefore,
developing sitespecific toxicity criteria for the WET testing
parallels the intent of the sitespecific procedures for
chemical criteria. WET can also be subject to the same concerns
observed with site water chemistry variability and, therefore,
must be considered in the water effects ratio (WER) development.