We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Clean Water Act Analytical Methods

Acute Toxicity WET Methods

Freshwater and Marine Organisms

This manual describes test procedures for effluents and receiving waters and includes guidelines on test species selection 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 to 96 hours.

The methods are approved under Clean Water Act section 304(h) and specified at 40 CFR 136.3, Table I A.

You may need Adobe Reader to view files on this page. See EPA’s About PDF page to learn more.