00-19116. Whole Effluent Toxicity Test Methods Guidance; Notice of Availability

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of availability.

SUMMARY:

Today, EPA is announcing the availability of a document titled, “Method Guidance and Recommendations for Whole Effluent Toxicity (WET) Testing (40 CFR Part 136).” This guidance document updates recommendations and suggestions (with additional technical clarification) regarding WET test methods published by EPA and incorporated by reference into regulations. The document includes specific technical guidance on nominal error rate adjustments, confidence intervals, concentration-response relationships, dilutions series selection, and dilution water.

DATES:

This notice will become effective July 28, 2000.

ADDRESSES:

A copy of the guidance document and supporting materials are available for review at the EPA Water Docket at EPA Headquarters at Waterside Mall, Room EB57, 401 M Street, S.W., Washington, DC 20460. For access to the Water Docket, call [phone] between 9:00 a.m. and 3:30 p.m. Eastern Standard Time for an appointment.

FOR FURTHER INFORMATION CONTACT:

Marion Kelly at the U.S. Environmental Protection Agency, Office of Water, Engineering and Analysis Division (4303), 1200 Pennsylvania Avenue, NW, Ariel Rios Building, Washington, DC 20460, call [phone], or E-mail [e-mail]; or John Fox at the U.S. Environmental Protection Agency, Office of Water, Engineering and Analysis Division (4303), 1200 Pennsylvania Avenue, NW, Ariel Rios Building, Washington, DC 20460, call [phone], or E-mail [e-mail].

SUPPLEMENTARY INFORMATION:

In 1995, EPA amended the “Guidelines Establishing Test Procedures for the Analysis of Pollutants,” at 40 CFR part 136, to add WET test methods to the list of Agency approved methods in Tables IA and II, for CWA data gathering and compliance monitoring programs (60 FR 53529, October 16, 1995). Known as the “WET Methods rule,” the 1995 action amended 40 CFR 136.3 by standardizing analytical methods that employ freshwater, marine, and estuarine vertebrates, invertebrates, and plants to directly measure the acute and short-term chronic toxicity of effluents and receiving waters. The WET Methods rule incorporated the following three technical documents by reference: Methods for Measuring the Acute Toxicity of Effluents and Receiving Water to Freshwater and Marine Organisms; Fourth Edition, August 1993 (EPA/600/4-90/027F); Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Water to Freshwater Organisms, Third Edition, July 1994 (EPA/600/4-91/002); and Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Water to Marine and Estuarine Organisms, Second Edition, July 1994 (EPA/600/4-91/003). In 1999, EPA promulgated technical corrections that incorporated an errata document into the WET Methods rule. EPA intended that the errata document correct minor errors and omissions, provide clarification, and establish consistency among the WET rule and test manuals (64 FR 4975, February 2, 1999).

Today's notice announces the availability of an additional document, “Method Guidance and Recommendations for Whole Effluent Toxicity (WET) Testing (40 CFR Part 136),” EPA/821/B-00/004. This guidance document provides clarification and recommendations to EPA Regional, State, Tribal and local regulatory authorities; regulated entities; and environmental laboratories regarding specific recommended and/or suggested technical elements of the WET test methods. The document provides specific guidance on nominal error rate assumption adjustments, confidence intervals, concentration-response relationships, dilution series selection, and dilution water. EPA prepared the document as part of a settlement agreement to resolve litigation challenging the rulemaking that standardized the testing procedures. The complete text of this Federal Register notice and the subject guidance document may be viewed or downloaded on the Internet at http://www.epa.gov/​OST/​WET/​.

Dated: July 24, 2000.

Linda B. Wilbur,

Acting Director, Office of Science and Technology.