[Federal Register Volume 61, Number 153 (Wednesday, August 7, 1996)]
[Notices]
[Pages 41149-41152]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-20114]


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ENVIRONMENTAL PROTECTION AGENCY
[FRL-5548-6]


Stakeholders' Meeting on Whole Effluent Toxicity (WET) 
Implementation Issues

ACTION: Notice of Stakeholders' Meeting on Whole Effluent Toxicity 
(WET) Implementation Issues and Request for Additional Implementation 
Issues.

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SUMMARY: The Environmental Protection Agency (EPA) is announcing a 
stakeholder's meeting for reviewing WET implementation issues to be 
held on September 24-26, 1996 at the Georgetown University Conference 
Center. WET implementation issues which were raised by stakeholders at 
a May 16, 1996 scoping meeting are described below. EPA is soliciting 
additional issues for discussion at the September 1996 meeting.

DATES: The stakeholders' meeting on WET implementation issues is 
scheduled for Tuesday, September 24, through Thursday, September 26, 
1996. Meeting attendees should register by August 30, in order to allow 
EPA to plan facilitation of breakout sessions. Additional 
implementation issues should be submitted on or before September 3, 
1996 to Debra Denton, EPA, via fax at (415) 744-1873 or electronic 
mail: [email protected].

ADDRESSES: The stakeholders' meeting will be held at the Georgetown 
University Conference Center in Washington, DC. To pre-register for the 
meeting, please fax your first and second preferences for breakout 
sessions along with your name, title,

[[Page 41150]]

organization, mailing address, phone number, fax number, and E-mail 
address (if available) to (703) 903-1374, attention Ms. Betty Peterson, 
Science Applications International Corporation, 1710 Goodridge Drive 
Mail Stop 1-11-7, McLean, Virginia 22102; phone number (703) 917-8240.

FOR FURTHER INFORMATION: To reserve a room for the meeting, contact 
Georgetown University Conference Center, 3800 Reservoir Road, NW, 
Washington, DC 20057; to reserve single rooms @ $108 + 13% DC tax + 
$1.50 occupancy tax and double rooms @ $133 + 13% DC tax + $1.50 
occupancy tax. Rates will be guaranteed until September 3, 1996. 
Parking is $8/day for hotel guests and other conference participants. 
Phone: (202) 687-3200, fax (202) 687-3291.
    Transportation from the area airports can be made by: contacting 
the Washington Flyer to arrange shuttle service from Washington 
National and Washington Dulles Airports at (703) 685-1400.
    The blue Georgetown University Transportation Service (GUTS) 
Shuttle from Dupont Circle Metro and Rosslyn Metro to the Leavy Center 
at Georgetown University runs: 6:15 am to 9:30 am every 15 minutes and 
9:45 am to 8:40 pm every hour. Cost is $1.00. Phone: (202) 687-4364.

SUPPLEMENTARY INFORMATION:

Draft Agenda

Tuesday, September 24, 1996

11:00-1:00 pm  Registration and pick up meeting package
1:00-3:00 pm  Plenary session, goals and ground rules
3:00-5:00 pm  Breakout sessions to discuss and prioritize issues

Wednesday, September 25, 1996

8:00-12:00 am  Continuation of breakout sessions
12:00-1:00 pm  Lunch
1:00-4:00 pm  Continuation of breakout sessions
4:00-5:00 pm  Large group session

Thursday, September 26, 1996

8:00-12:00 pm  Breakout sessions
12:00-1:00 pm  Lunch
1:00-5:00 pm  Large group session presentations and next steps
5:00 pm  Adjourn

Background

    The U.S. Environmental Protection Agency's (EPA) National Pollutant 
Discharge Elimination System (NPDES) permit program utilizes Whole 
Effluent Toxicity (WET) testing and monitoring to ensure that ``no 
toxics in toxic amounts'' will be discharged into the Nation's waters. 
Over the past few years, a number of issues have arisen as a result of 
increasing experience with WET limits and monitoring requirements. EPA 
is undertaking a series of initiatives designed to make any appropriate 
``mid-course'' adjustments reflecting the science underlying WET, as 
well as to better support ongoing WET implementation. During September 
1995, the Society of Environmental Toxicology and Chemistry (SETAC) 
sponsored a workshop on WET in Pellston, Michigan. This workshop was 
co-funded by the American Industrial Health Council, the Association of 
Metropolitan Sewerage Agencies, and EPA. The purpose of the Pellston 
Workshop was for nationally recognized scientists from government, 
academia and industry to look at the scientific basis of the WET 
program. SETAC will publish written proceedings from this workshop 
shortly. EPA held an open forum on December 5, 1995, in Crystal City 
Virginia to report results of the Pellston WET Workshop to interested 
stakeholders. At that time, EPA promised to hold an open meeting to 
discuss the implementation issues surrounding WET.
    Today, EPA is announcing a stakeholders' meeting for reviewing WET 
implementation issues to be held on September 24-26, 1996 at the 
Georgetown Conference Center in Washington, DC. The purpose of this 
meeting is to examine issues surrounding the implementation of the WET 
program. EPA will consider all the points raised, but the Agency cannot 
make policy decisions at this meeting. The Agency will, however, 
develop a follow-up action plan at the conclusion of the meeting. In 
the interim, it is EPA's position that the WET program is technically 
and scientifically based and that the options and suggestions resulting 
from the implementation meeting being announced today will only serve 
to strengthen the existing WET program.
    In order to prepare for the September meeting, the Agency held a 
small group scoping meeting on May 16, 1996. EPA invited States, 
environmental groups, and members of the regulated community to attend 
this meeting. The attendees at the small group WET scoping meeting 
included the American Auto Manufacturers Association (AAMA), the 
American Forestry and Paper Association (AFPA), National Council for 
Air and Stream Improvement (NCASI), the Association of Metropolitan 
Sewerage Agencies (AMSA), the American Petroleum Institute (API), the 
Western Coalition of Arid States (WESTCAS), and the EPA. At this 
scoping meeting the participants listed out the issues which were of 
most concern to their organizations with respect to WET implementation. 
A summarized list of these WET implementation issues raised at the May 
16, 1996 scoping meeting follows and is broken out into four 
categories: Water Quality Criteria/ Standards; Exposure Assumptions; 
NPDES Permits; and Enforcement/Compliance issues.

Water Quality Criteria/Standards Issues

    1. Narrative vs. numeric WET criteria: With respect to WET: (1) 
Should EPA guidance clarify that State and Tribal WET criteria can be 
written as narrative with implementation procedures (e.g., no toxics in 
toxic amounts) or numeric (e.g., 1.0 TUc, chronic toxic unit), or on a 
case-specific basis? (2) Should different segments of a waterbody have 
different water quality standards, which vary in criteria or beneficial 
uses? (3) How should toxicity, which does not cause an exceedance of a 
water quality standard, be addressed?
    2. Duration, frequency and magnitude criteria components: With 
respect to WET: (1) Are the current criteria protective for saltwater, 
estuarine, intermittent or variable flow discharges? How should these 
factors be considered in criteria development (e.g., should duration of 
the criteria be made consistent with the exposure period used in the 
tests and permit limits?). (2) Since most chronic test durations have 
become abbreviated from 30 to 7 days, should the acute and chronic 
toxicity criteria be re-defined to be made consistent with the toxicity 
test method frequency? (3) Should EPA re-evaluate the toxic unit 
definitions, data supporting the one hour duration period for acute 
criteria and the once in 3 year exceedance frequency exposure and re-
emphasize support of inhibition concentration response (IC25) in 
determining test results.
    3. Flexibility vs. consistency in WET criteria: (1) Where is the 
balance between flexibility and consistency in the application of WET 
criteria? (2) Is it necessary for test species to be indigenous to the 
receiving water? (3) Is it appropriate to allow testing with resident 
species (considering species-specific sensitivity to classes of 
toxicants) and appropriate designated uses? (4) Is there flexibility in 
conducting a reasonable potential analysis for WET?
    4. Independent Application Policy: (1) What options are there for 
using WET as an indicator of water quality? (2) What options are 
available for consideration

[[Page 41151]]

of ``weight-of-evidence'' instead of independent applicability of 
biological assessments, WET results, and chemical analyses? (3) What 
does the data show with respect to WET tests predicting in-stream 
effects in waters having low chronic toxicity or in waters that are 
effluent dependent?

Exposure Assumption Issues

    1. WET-specific exposure issues: Identify issues that are specific 
to WET as opposed to those that are in common for other parameters 
(e.g., exposure assumptions may be difficult for storm water discharges 
or for characterizing ephemeral streams)?
    2. Critical flows and modeling inputs: What critical flows and 
types of models (e.g., dynamic models for ocean discharges) should be 
used in assessing exposure and beneficial use designation?
    3. Application of mixing zones for WET: What are the applications 
(e.g., critical flows) and limitations for WET mixing zones in 
saltwater, freshwater, storm events, and flash floods? Should WET 
criteria be applied at the end-of-pipe? Under what circumstances is it 
appropriate to apply WET criteria at the end-of-pipe instead of 
allowing a mixing zone?
    4. Balancing exposure assumptions with test duration: Is it 
necessary that toxicity test method duration match expected the 
criteria exposure duration?
    5. Balancing test method dilution water with receiving water 
characteristics: (1) What test species should be used when testing a 
freshwater discharge to an estuarine water body, especially when 
testing at high effluent concentrations? (Sometimes ionic imbalances 
can contribute to the observed WET toxicity.) (2) Will EPA reconsider 
the use of synthetic water which lacks the hardness, organic content, 
and other attenuating capacities of natural, upstream water? (3) Should 
test methods be conducted to take into account site-specific factors, 
such as ionic characteristics of receiving water?

NPDES Permit issues

    1. Expression of WET limits: (1) How should WET test method 
variability be addressed or accounted for when reporting WET test 
results? (2) Should permit limits be expressed in terms of toxicity 
units (e.g., TUa, TUc) or should percentage of effluent (e.g., must 
meet at 75% effluent) be used? (3) Can permit limits account for toxic 
effects of ionic imbalance? (4) Should the averaging period for WET 
limits be consistent with the exposure period of the tests (e.g., acute 
WET as a 48-hour average rather than a daily maximum) or should EPA 
increase daily maximums to compensate for the shorter exposure period? 
(5) Are acute toxicity end-of-pipe limits at 1.0 acute toxic unit (TUa) 
or greater scientifically valid? (6) Do magnitude and exposure 
assumptions (e.g., 7Q10 flows vs. continuous flows or Monte Carlo 
models) used to develop limits reflect actual exposure? (7) How are WET 
limits applied to effluents discharging into intermittent and effluent-
dominated streams? (8) Should permits in arid areas monitor only for 
acute effects if chronic limits are inappropriate and the flow is 
beneficial?
    2. Fair notice in permit: (1) Should permits contain specific 
language stating what the permittee needs to do to comply with the 
permit requirements (vs. providing cites to regulations)? (2) How much 
detail is desirable? (3) Can EPA change the discharge monitoring report 
with respect to the certification that WET test results are accurate, 
because ``there is no true value [in WET tests] from which to measure 
deviations and to determine bias or accuracy (54 FR 50218)?''
    3. Re-evaluate/define reasonable potential determinations: (1) Do 
small data sets critically affect the flexibility available for 
conducting a reasonable potential analysis? (2) Are there alternative 
method detection levels/quantitation levels for WET test methods which 
can be used in reasonable potential determinations? (3) Will reasonable 
potential determinations eliminate setting permit limits for water 
quality not limited to discharge quality?
    4. Water conservation leading to toxicity--conflicting 
environmental goals: How should conflicting environmental goals be 
reconciled? For example, water conservation is not encouraged with end-
of-pipe limits.
    5. Tiered procedures for TRE/TIEs--cross-over to enforcement: (1) 
Can EPA provide guidance on when to set permit limits, establish 
monitoring, and begin TIE/TREs? (2) How could EPA address inconclusive 
TIEs/TREs? (3) Should permits only require a trigger for further 
testing or conducting a TIE/TRE instead of penalties? (4) Should the 
test species used in the toxicity identification evaluations (TIEs) or 
toxicity reduction evaluations (TREs) be the same test species used for 
NPDES compliance testing? (5) Should TIE and TRE procedures only use 
methods with standard and/or codified guidelines?
    6. Low chronic toxicity: (1) Since many discharges have improved 
the quality of their discharges, the focus is moving from acute to 
chronic toxicity. Can EPA identify procedures to determine when 
apparent exceedences are caused by test variation and treatment plant 
fluctuations (effluent variability) and procedures for TIEs/TREs to 
identify and remove toxicants? (2) Evaluate whether the NOEC level may 
be set at >90% effluent? (3) Can chronic WET tests be used as a 
monitoring trigger for increased monitoring and conducting a TIE/TRE as 
opposed to a permit limit? (4) What are the technical limits of TIE/TRE 
in reducing chronic toxicity to acceptable levels?
    7. Ubiquitous pollutants: What are effective ways in the permit 
process to deal with ubiquitous pollutants (e.g., diazinon, 
chlorpyrifos) that have been identified in the TRE/TIE process?
    8. EPA-approved chemicals causing toxicity: (1) How could the 
approval process for pesticides and other chemicals (e.g., treatment 
additives) be reconciled with the permitting process? (2) Can permit 
limits for total dissolved solids or chlorides replace a WET limit when 
common salts are the toxicants?
    9. Correlate permit limits to exposure assumptions: (1) How could 
permit limits be more realistically linked to exposure assumptions? (2) 
Can EPA encourage wider use of available exposure models? Can WET 
limits have mixing zones to reflect allowable dilution?
    10. IU WET limits to POTWs: Should WET limits be applied to 
industrial users (IUs), and if so, how can test results account for 
downstream POTW treatment processes?
    11. Reevaluation of toxic units: Which statistical endpoint is best 
for expressing toxicity (e.g., no observed effect concentration or 
effect concentration? What allowed effect or inhibition concentration 
(e.g., IC25) is appropriate?
    12. Analytical variability in reporting (quantitation/detection 
issues): (1) What are the best and technically available ways to deal 
with test variability? (2) Are there options for addressing test-
specific inter-laboratory variability in order to account for test 
variability in permit limits?
    13. Application of test methods in permits: (1) Are non-lethal 
chronic endpoints equivalent to acute endpoints? (2) Is it possible to 
either establish test precision criteria for test methods or determine 
the lowest reliable level response? (3) Can EPA methods specify culture 
media in order to improve the health of cultures and reliable 
endpoints? (4) Can EPA determine the accuracy of all WET test methods? 
(5) How does EPA justify the Selenastrum 4-day growth test use of EDTA 
except in tests with metals

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present? If algal growth test results cannot predict toxicity in a 
reservoir, will EPA restrict use of certain test species in large water 
bodies? (6) How to address toxicity caused by artifacts of the test 
methods. (7) How should WET testing be conducted when in-stream 
conditions differ substantially from WET toxicity test methods (e.g., 
temperature, hardness)?

Compliance and Enforcement Issues

    1. Single exceedance: (1) Are there alternatives for dealing with a 
single test failure that results in a WET limit exceedance (e.g., 
further testing and TIE/TRE where appropriate, as agreed to by 
regulatory agencies and permittees)? (2) Can EPA evaluate the Pellston 
findings that concluded that usually episodic exceedances (especially 
one chronic test failure) would not impact the receiving system? (3) 
Will one violation be subject to enforcement actions?
    2. Inconclusive TRE/TIEs: (1) How should inconclusive (i.e., no 
sources of toxicity identified) TRE/TIEs be treated by regulatory 
authorities? (2) Should more guidance be given on what is an acceptable 
TIE/TRE? (3) Should a pattern of toxicity be observed before compliance 
actions are initiated? (4) How should low level chronic toxicity be 
addressed when conducting a TIE?
    3. Test/data variability in determining compliance: (1) How should 
EPA consider data variability when determining compliance (especially 
since laboratories with low test variability are more likely to detect 
test failure)? (2) For a LC50 value greater than 100 percent effluent, 
how should compliance be determined? (3) Should EPA provide a 
laboratory certification for WET testing and a more rigorous test 
acceptance criteria program?
    4. Fair notice (cross over w/permits). How should permits be 
written to bring closure to (successful/unsuccessful) TIE/TREs?
    5. ``Good actor'' relief in TIE/TRE: When WET limits continue to be 
exceeded while TIE/TRE is being conducted, is the permittee subject to 
enforcement action?
    6. Ability to track permit conditions: Narrative limits could be 
viewed differently than numeric limits.
    7. Treatment chemicals causing toxicity: How can compliance 
determinations account for use of EPA-registered pesticides or common 
salts causing ionic imbalance toxic effects from salinity?

    Dated: July 31, 1996.
Michael B. Cook,
Director, Office of Wastewater Management.
[FR Doc. 96-20114 Filed 8-6-96; 8:45 am]
BILLING CODE 6560-50-P