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Water: Whole Effluent Toxicity

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms

This manual describes test procedures for effluents and receiving waters and includes guidelines on laboratory safety, quality assurance, facilities and equipment, dilution water, effluent sampling methods and holding times, test specied selection, data analysis, report preparation, organism culturing and handling, and mobile toxicity test laboratory design. The acute toxicity tests generally involve exposure of any of 20 test organisms to each of five effluent concentrations and a control water. The test duration ranges from 24-96 hours. This manual contains specified test conditions for commonly used freshwater and marine organisms:

  1. Ceriodaphnia dubia
  2. Daphnia magna and D. pulex
  3. brine shrimp (Artemia salina)
  4. fathead minnows (Pimephales promelas)
  5. rainbow trout (Oncorhynchus mykiss)
  6. brook trout (Salvelinas fontinalis)
  7. mysids (Americamysis bahia and Holmesimysis costata)
  8. sheepshead minnows (Cyprinodon variegatus)
  9. sliversides (Menida menidia, M. beryllina, and M. peninsulae)

At present, most graphics associated with this document are not included.

Browse Introduction

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  • Complete Document (PDF) (275 pp., 2.5 MB)
  • Table of Contents (PDF) (94 K, 6 pp)
  • Sections 1-6 (PDF) (389 K, 39 pp)
    • Introduction
    • Types of Tests
    • Health and Safety
    • Quality Assurance
    • Facilities, Equipment, and Supplies
    • Test Organisms
  • Sections 7-10 (PDF) (414 K, 40 pp)
    • Dilution Water
    • Sampling and Sample Handling
    • Acute Toxicity Test Procedures
    • Test Data
  • Sections 11-12 (PDF) (493 K, 53 pp)
    • Data Analysis
    • Report Preparation
    • Bibliography
  • Appendix A, part A (PDF) (407 K, 53 pp)
    • Distribution, Life Cycle, Taxonomy, and Culture and Holding Methods for Ceriodaphnia dubia, Daphnia (D. Magna and D. Pulex), Mysids (Mysidopsis bahia), and Brine Shrimp (Artemia salina)
  • Appendix A, part B (PDF) (60 pp, 674 K)
    • Distribution, Life Cycle, Taxonomy, and Culture and Holding Methods for fathead Minnow (Pimephales promelas), Rainbow Trout (Oncorhynchus mykiss) and Brook Trout (Salvelinus fontinalis), Sheepshead minnow (Cyprinodon variegatus), and Silversides (Menidia SPP)
  • Appendices B-E (PDF) (406 K, 29 pp)
    • Supplemental List of Acute Toxicity Test Species; Dilutor Systems; Plans for Mobile Toxicity Test Laboratory; Check Lists and Information Sheets

Supporting Rule

Guidelines Establishing Test Procedures for the Analysis of Pollutants; Whole Effluent Toxicity Test Methods; Final Rule (November 19, 2002) In this final regulation, we ratified approval of several test procedures for measuring the toxicity of effluents and receiving waters. The test procedures are commonly referred to as whole effluent toxicity or WET test methods. We also withdrew two WET test methods from the list of nationally-approved biological test procedures for the analysis of pollutants. This action also revises some of the WET test methods to improve performance and increase confidence in the reliability of the results. This action satisfies settlement agreement obligations designed to resolve litigation over an earlier rulemaking that originally approved WET test methods.


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