> March 29, 2005

U.S. Environmental Protection Agency

Water Docket in the EPA Docket Center

Mail Code 4101T 1200 Pennsylvania Ave., NW

Washington, DC 20460

**Docket ID No. OW-2004-0037**

**Draft National Whole Effluent Toxicity Implementation Guidance**

Dear Ladies and Gentlemen:

We have reviewed the draft *National Whole Effluent Toxicity
Implementation Guidance*. We find that it contains much useful
information. Unfortunately, it also includes guidance that, if followed,
will lead permit writers to fail to include Whole Effluent Toxicity
(WET) limits in permits for which such limits are needed to protect the
environment and required by existing federal regulations. There is
simply no excuse for failing to include WET limits in permits where any
uncertainty regarding the need for such limits was created by the permit
applicant's failure to collect any or a sufficient number of WET samples
to determine if there is a reasonable potential to violate state numeric
or narrative water quality standards.

At present there are many states that, as a matter of practice, refuse
to include WET effluent limits in their permits. Illinois, Vermont, and
New York have not implemented WET effluent limits in NPDES permits and
USEPA's proposed "step-wise" approach to WET testing and effluent limits
would continue to allow these states and others to avoid the inclusion
of WET effluent limits in their permits.

The most disturbing aspect of this guidance is USEPA's advice that
states incorporate a "compliance schedule" that has a "delayed effective
date that allows time for the permittee to gather up to 10 samples to be
used to validate the finding of the need for a permit limit..." This
approach is directly contradictory to that recommended by USEPA in its
*Technical Support Document for Water Quality Based Toxics Control
(EPA/505/2-90-001)* (hereafter TSD). On page 59 of the TSD it clearly
states,

> "EPA believes that "reasonable potential" is shown where an effluent
> is projected to cause an excursion above the CCC \[criteria continuous
> concentration\] or CMC \[criteria maximum concentration\]. This
> projection is based upon a statistical
>
> analysis of available data that accounts for limited sample size and
> effluent variability. EPA's detailed recommendations for making a
> statistical determination based upon effluent monitoring data alone
> are shown in Box 3-2. Where a regulatory authority finds that test
> results alone indicate a "reasonable potential" to cause an excursion
> above a State water quality criterion in accordance with 40 CFR
> 122.44(d)(l)(ii), a permit limit must be developed."

The data collected, even if fewer than 10 data points, should determine
whether a WET effluent limit is necessary, period. The approach being
suggested by USEPA in the *Draft National Whole Effluent Toxicity
Implementation Guidance* is to have dischargers take a minimal amount of
data (for example the 4 minimum WET tests required by federal
regulations for POTWs) and, if that data indicates a reasonable
potential for toxicity in the effluent, to require more data to be
collected, rather than to institute WET effluent limits as required by
40 CFR 122.4 (d).

It is not USEPA's job to protect dischargers from the paucity of data
they are required to collect. It should be noted that some states, most
notably Vermont, are not requiring POTWs to adhere to USEPA's
regulations that require a minimum of 4 WET tests, much less include WET
effluent limits in permits. For USEPA to propose rewarding dischargers
for conducting minimal testing (or in Vermont not even conducting the
minimum) by being granted up to 18 months to collect additional data in
the hopes that this will decrease the likelihood of needing a permit
limit is completely unacceptable.

The statistical procedures USEPA published in the TSD are based on
numerous studies done to characterize effluents from a variety of
sources. These procedures are adequate for determining whether WET
limits are required and these procedures should be adhered to. If a
discharger chooses to conduct more frequent WET testing than their
permit requires, that data should be reported in accordance with 40 CFR
122.44 (j) and it should rightly be used in the calculation of
reasonable potential. However, if a discharger only does the minimal
amount of sampling, and that sampling indicates toxicity, they should
not be given a second bite at the apple to try and demonstrate effluent
limits are unnecessary. When toxicity is detected, or when sampling data
indicates a reasonable potential to violate numerical or narrative
toxicity standards, WET limits should immediately be required, in
accordance with the plain language of 40 CFR 122.44(d). At that point
the discharger will be collecting the additional data necessary,
enforceable permit limits will be in place should toxicity continue, and
the discharger will have an opportunity to demonstrate a history of
compliance

The approach USEPA is proposing in this guidance also encourages states
to ignore other factors that should be considered when WET effluent
limits are contemplated in a permit, such as the sensitivity of aquatic
species that are present in the receiving waters. WET testing is
normally done using a limited number of surrogate species, usually
*ceriodaphnia* and the fathead minnow. While these two species are
representative surrogates for common fish and invertebrates, they may
not be representative of the actual biota in the receiving waters. For
instance, a discharge might go into a stream where sensitive species are
present but WET tests on fathead minnows show no or only slight
toxicity. With regards to the more sensitive species in the receiving
waters the toxicity might be more acute than the WET tests on fathead
minnows indicate. Under USEPA's proposal, the discharger would be
granted up to 18 months to conduct follow up WET tests under the
so-called "compliance schedule" all the while subjecting life in the
receiving waters to chronic or acute toxicity. The additional testing
done on the surrogate species, however, might never indicate toxic
impacts. The result is the receiving waters being subjected to toxic
impacts, a permit condition never having been instituted, and, because
no violation of permit conditions has occurred, the discharger escaping
any enforcement action either from USEPA, the states, or citizens.

This proposed guidance clearly does not protect the environment. It
clearly does violate 40 CFR 122.44 (d) that provides that NPDES permits
must prohibit discharges that might cause or contribute, or have a
reasonable potential to cause or contribute, to a violation of state
numeric or narrative water quality standards.

In addition to being unprotective of the environment and a violation of
federal law, this draft guidance establishes perverse incentives for
permit applicants. It encourages applicants to collect the minimal
amount of data with the knowledge that if toxicity is detected they will
be giving up to 18 months to collect data for the purpose of disproving
the previous results This will be done before enforceable effluent
limits are even considered. The proposed guidance also validates the
approach of recalcitrant states like Illinois, Vermont, and New York,
that have never adequately monitored WET nor included WET effluent
limits in permits. Moreover, the proposed guidance encourages states to
"look the other way" when the reasonable potential for toxic discharges
exists, to ignore the unambiguous requirements of 40 CFR 122.44(d) to
require effluent limits, and to ignore the potential impacts of toxicity
on the nation's waters.

We believe that USEPA should continue to require states to follow the
statistical procedures described in the TSD, and abandon the approach
preferred in its proposed guidance. At a minimum it should retract its
recommendations under Section 5 for a delayed compliance schedule. USEPA
should continue to require states to adhere to the plain language of 40
CFR 122.44(d) for assigning effluent limits and require states to
utilize the procedures described in the TSD for making a scientifically
defensible determinations of when effluent limits are necessary.

> ![](media/image3.png){width="1.95625in"
> height="0.9729166666666667in"}Sincerely,

Robert Moore, Executive Director Albert Ettinger, Senior Staff Attorney

Environmental Advocates of New York Environmental Law & Policy Center