United States Environmental Protection Agency Office of Water (4303T) EPA-821-F-02-024 October 2002 Fact Sheet Guidelines Establishing Test Procedures for the Analysis of Pollutants; Whole Effluent Toxicity Test Methods; Final Rule Summary EPA is approving revisions to several whole effluent toxicity (WET) test methods that are currently approved at 40 CFR Part 136. These methods are for use in Clean Water Act (CWA) data gathering and compliance monitoring programs. In addition, this final rule ratifies EPA's previous approval of ten WET methods at 40 CFR Part 136 for nationwide use and removes two other methods from the Part 136 listing. Background In 1995, EPA amended the "Guidelines Establishing Test Procedures for the Analysis of Pollutants" to add a series of standardized whole effluent toxicity (WET) test methods to the list of methods approved at 40 CFR Part 136 (WET final rule). The WET final rule approved 17 methods for measuring the acute and short- term chronic toxicity of effluents and receiving waters to freshwater, marine, and estuarine organisms. Several parties filed suit challenging the 1995 rulemaking. To resolve that litigation, EPA entered into settlement agreements with them. This final rule partially fulfills the requirements of two settlement agreements between EPA and stakeholders (Edison Electric Institute etal. v. EPA, Settlement Agreement, July 24, 1998, and Lone Star Steel v. EPA, Settlement Agreement, March 4, 1998). Final Rule This final rule updates WET test methods, to makes minor corrections and clarifications, and addresses specific stakeholder concerns. Updates include revised method precision statements that reflect recent variability studies, incorporation of all previous addenda and errata, and corrections for additional technical errors not noted in previous errata. Revisions also address the following specific stakeholder concerns: • blocking by known parentage • pH drift • concentration-response relationships • confidence intervals • dilution series selection • dilution water acceptability • pathogen interference Lastly, this final rule ratifies ten methods that are approved at 40 CFR Part 136 for nationwide use and removes two other methods from the Part 136 listing. Additional Information and Copies For further information concerning this final rule, please contact Marion Kelly at the U.S. EPA Office of Water, Engineering and Analysis Division (4303), 1200 Pennsylvania Avenue, Washington, D.C. 20460; (Email: kelly.marion@epa.gov) or Debra Denton at U.S. EPA Region 9, c/o SWRCB, 1001 I Street, Sacramento, CA 95814 (E-mail: denton.debra@epa.gov). You may view or download the complete text of the Federal Register notice and the revised editions of the three supporting WET method manuals on the Internet at http://www.epa.gov/waterscience/WET. You can find all references cited in the preamble through the Water Docket, EPA West Building, Room B135, 1301 Constitution Ave. NW, Washington, D.C. 20004; (e-mail: OW- docket@epa.gov). ------- |