AMSA Regulatory Alert (RA 01-17)

To: Members & Affiliates
From: National Office
Date: October 4, 2001
Subject: CALL FOR COMMENTS ON EPA’S PROPOSED WHOLE EFFLUENT TOXICITY TEST METHODS
Reference: RA 01-17

Action Please By:
November 13, 2001

On September 28 the Environmental Protection Agency (EPA) issued for comment proposed Guidelines Establishing Test Procedures for the Analysis of Pollutants; Whole Effluent Toxicity Test Methods (66 Fed. Reg. 49,794). The rule proposes to ratify several analytic test procedures measuring whole effluent toxicity (WET) and to modify other WET test methods, originally added to 40 CFR Part 136 in October 1995 (60 Fed. Reg. 53,529). EPA intends for the proposed changes to improve the performance of the WET tests, and thus increase confidence in the reliability of the results obtained using the tests.

Many of AMSA’s concerns about WET testing raised to date are not addressed in the proposal. AMSA will be assembling comments on the proposal and is looking for input from the membership. Comments on the proposal are due to EPA by November 27, 2001. If you would like to contribute to AMSA’s comment efforts, please contact Chris Hornback, AMSA at 202/833-9106 or chornback@amsa-cleanwater.org. Submissions for inclusion in AMSA’s comments on the rule must be received by November 13, 2001.

Background
The September 28 proposal satisfies obligations in a 1998 settlement agreement designed to resolve litigation over EPA’s October 1995 final rule. The final rule introduced and endorsed 17 acute toxicity methods and short-term methods for estimating chronic toxicity of effluents. Following issuance of the 1995 final rule, several groups filed suit challenging the rulemaking (Edison Electric Institute, et al. v. EPA), citing concerns with methods that generated false positives and exaggerated the toxicity of effluent discharges. As part of the 1998 settlement, the Agency agreed to validate 12 of the 17 methods proposed in the October 1995 rule.

To validate the test procedures, EPA conducted an interlaboratory variability study (WET Variability Study) in 1999 and 2000. AMSA participated in the interlaboratory study and sponsored laboratories using AMSA’s technical action fund (TAF) and support from 43 AMSA members. EPA published preliminary results from the WET Variability Study in October 2000 and submitted the results for peer review in 2001. The September 28 rule announces the publication of the final report.

During the entire validation process and in the months following the peer review, AMSA has continued an active dialogue with EPA on WET issues. In an August 14, 2001 letter to Geoff Grubbs, Director of EPA’s Office of Science and Technology (OST), AMSA recommended that EPA incorporate in 40 CFR Part 136 a "Percent Effect Approach" to quantify the level of biological impact that can be detected above what is commonly recognized as "noise" in the methods. AMSA also recommended that EPA address the high failure rate encountered by the laboratories that participated in the WET Variability Study. Many laboratories failed to complete the procedures as required in the method instructions, which should have, but did not result in a required retest.

Details of the Proposal
The September 28 notice proposes to ratify 11 of the 12 methods in question. Of the 11 methods ratified, nine methods are ratified in an amended form. The other two methods (the Selenastrum capricornutum Growth Test and the Mysidopsis bahia Survival, Growth and Fecundity Test) are additionally amended to increase the performance of the procedures. EPA proposes to update the methods by incorporating previous method addenda and errata, and by revising method precision statements to reflect results from recent EPA studies. EPA also proposes method revisions in response to specific stakeholder concerns, including:

• Requiring "blocking" by known parentage in the Ceriodaphnia dubia Survival and Reproduction Test
• Adding procedures to control pH drift that may occur during testing
• Incorporating review procedures for the evaluation of concentration-response relationships
• Clarifying allowable nominal error rate adjustments
• Clarifying limitations in the generation of confidence intervals
• Adding guidance on dilution series selection
• Clarifying dilution water acceptability
• Adding procedures for determine and minimizing the impact of pathogens in the Fathead Minnow Survival and Growth Test

EPA proposes to withdraw Holmesimysis costata as an acceptable species for use in the Mysidopsis bahia Acute Test method and proposes a separate Holmesimysis costata Acute Test method.

AMSA’s request that EPA account for the variability and high failure rate of some of the methods during the WET Variability Study was not addressed. In fact, EPA states that the "analysis of interlaboratory precision data revealed that the WET test methods are sufficiently precise for use in NPDES permits." EPA also states in the preamble that the rulemaking focuses on analytic testing methodologies to measure WET, and not WET implementation generally. For this reason, no mention is made in the proposal about the Percent Effect Approach. AMSA continues to feel that some type of detection level concept, such as Percent Effect, is critical to WET implementation. Accordingly, AMSA has scheduled a meeting for November 5, 2001, with EPA’s Office of Wastewater Management and Office of Science and Technology, to discuss Percent Effect and other implementation issues. If you have any experiences with WET implementation you would like us to share with EPA during our November 5 please contact Chris Hornback at 202/833-9106 or chornback@amsa-cleanwater.org. A copy of AMSA’s August 14, 2001 letter to the OST can be found at: http://www.amsa-cleanwater.org/private/legreg/outreach/7-16-01wholeeffluent.pdf.   A copy of the September 28 Federal Register notice can be found at: http://www.epa.gov/fedrgstr/EPA-WATER/2001/September/Day-28/w24374.htm. Copies of the WET method manuals can be downloaded at: http://www.epa.gov/waterscience/WET/.