AMSA Regulatory Alert (RA 05-03)

To: Members & Affiliates
From: National Office
Date: February 15, 2005
Subject: AMSA ENCOURAGES MEMBERS TO COMMENT ON DRAFT WHOLE EFFLUENT TOXICITY IMPLEMENTATION GUIDANCE
Reference: RA 05-03

Action Please By:
March 18, 2005

On December 28, 2004, the U.S. Environmental Protection Agency (EPA or Agency) released for public comment its draft National Whole Effluent Toxicity (WET) Implementation Guidance Under the NPDES Program (Draft Guidance) (see AMSA’s Regulatory Alert 05-02 at http://www.amsa-cleanwater.org/private/regalerts/ra05-02.cfm). A copy of the 109 page guidance can be downloaded from EPA’s website (http://www.epa.gov/npdes/permitbasics). EPA’s original 60-day public comment period on the Draft Guidance has been extended and will now close on March 31, 2005. AMSA will submit comments on the draft and encourages its member agencies with WET limits or WET testing requirements in their National Pollutant Discharge Elimination System (NPDES) permits to review the guidance and submit their own comments. This Regulatory Alert includes a list of the major issues AMSA has identified in the Draft Guidance that its members may wish to address in their comments.

EPA will hold two listening sessions over the next month to provide stakeholders with an additional opportunity to voice concerns and offer input on the guidance. The first session will be held in Washington, DC on February 28, 2005 and the second will be in San Francisco on March 17, 2005. Additional details on the listening sessions are available on EPA’s website (http://www.epa.gov/npdes/permitbasics). AMSA will participate in the Washington, DC session and expects to have member representation at the March meeting. As AMSA works to prepare comments, we would like to address as many member concerns as possible. Please send any comments you have on the guidance to Chris Hornback, AMSA’s Director of Regulatory Affairs by March 18, 2005, so they can be incorporated into the Association’s comments.

Issues of Concern in Draft Guidance
The Draft Guidance was intended to provide more national consistency within the existing WET program and to address a number of issues and questions that have been raised by states, regions, and stakeholders. The Draft Guidance outlines options that states may consider to provide flexibility within the existing regulations, such as allowing additional time for permittees to collect more data to make the critical ‘reasonable potential’ assessment and using an enhanced approach to evaluating WET toxicity in low-flow dilution cases. However, AMSA is concerned with a number of issues both omitted from and included in the Draft Guidance and has prepared the following list to assist the membership in preparing comments.

1. EPA has not adopted the “step-wise” approach to WET on behalf of which AMSA and others have advocated. This approach would use confirmatory testing and toxicity investigation as the ‘limit’ in lieu of numeric limits, except when necessary. For example, we have supported the idea of accelerated testing and investigation in response to a failed test, where the initial failed test is not a violation and would not result in a numerical limit if the discharger can address the toxicity. However, EPA is using what it is calling a “step-wise” approach, but one that is very different from that supported by AMSA. Under EPA’s approach, the initial failed test would still be a violation and successfully eliminating the toxicity would neither constitute compliance nor preclude enforcement.
    
2. The Draft Guidance makes no reference to previous EPA policy that allows for enforcement discretion for single WET test failures. AMSA has learned that EPA’s enforcement office is separately developing a section on WET enforcement that will be released with the final guidance but will not be released for public comment. Although EPA is viewing these as separate items, AMSA believes the Draft Guidance should mention the enforcement issues.
    
3. The Draft Guidance states that the EPA Regions “shall” routinely inspect testing labs and develop WET guidance that is consistent with national EPA regulations, policy and guidance. Standards for lab inspections have not, however, been provided by EPA. EPA appears to be supporting adoption of test criteria or dose-response interpretation guidance as ‘requirements’ when they are not included in 40 CFR Part 136. While the draft is only guidance, it often sounds like regulation. Whether intended or not, the inflexibility of the language in the guidance could effectively eliminate flexibility in the program and ultimately result in all states using biased and flawed reasonable potential (RP) and permitting approaches.
    
4. The actual RP process as described in the WET Technical Support Document (TSD) is unchanged. The recent court decision on the WET methods [see Legal Alert 04-11, http://www.amsa-cleanwater.org/private/legalalerts/leg04-11.cfm] found that the use of toxicity units (TUs) will result in a "grossly inflated result" when calculating the coefficient of variability (CV) and the use of TUs to characterize the distribution of WET data is a "mistake", plus other numerous RP problems (see point #5 below). Given these findings, the approach in the guidance does not seem defensible.
   
   The guidance also clearly indicates that RP should be determined using point-estimates even if compliance is being determined with hypothesis tests. The guidance should specify the use of LC50 for acute and IC25 for chronic. The guidance should discourage the use of hypothesis tests for compliance in the NPDES program or at least include the same strong recommendation for the use of point-estimates found in the promulgated methods, the final rule, and the TSD.
    
5. The guidance has adopted AMSA's comment that more data should be collected prior to conducting the RP determination, but without addressing other significant concerns. Collection of more data will only increase the probability that a discharger will receive a limit, regardless of actual environmental risk, because of test variability. A test will fail eventually if you test often enough, particularly when dilution is not available. The false positive concern is exacerbated by the fact that there are no detection limits for these methods and that hypothesis test results are frequently used for compliance monitoring.
    
6. Although EPA has offered monthly median limits for WET in the guidance to address variability when dilution is low instream, this approach may not significantly help dischargers because at least two additional tests will be required in the same month to attain the monthly median limit if the first test suggests unacceptable toxicity. This will be difficult to do if agencies contract out their acute tests and may be impossible if they contract out their 7-day chronic tests (particularly mysid and daphnid chronic tests). EPA's approach to assessing toxicity at low dilution is not practical, and the ‘benefits’ of this new provision do not outweigh its shortcomings.
    
7. Also of concern are the 24-month TRE limit and the single test limit of 1.6 TUc for chronic toxicity. Given the warnings in the recent WET litigation decision about the use of single tests for compliance, such a limit should not be recommended. Further, given EPA's own admission that the precision of WET results is plus or minus 100%, a single test limit should be at least 2.0 TUc.

Again, AMSA will be preparing comments on the Draft Guidance by the March 31, 2005 deadline, and encourages its members to prepare comments on behalf of their agencies. Please send any comments you have on the guidance to Chris Hornback, AMSA’s Director of Regulatory Affairs by March 18, 2005, so they can be incorporated into the Association’s comments.