NPDES - Whole Effluent Toxicity (WET)
Contact: Glen Schmitt 517-290-6424
Whole-effluent toxicity (WET) is the combined toxic (poisonous) effect of an effluent on aquatic animals (fish, crustaceans, etc.). The State of Michigan regulates WET through a water discharge permit system (NPDES) and other regulatory venues under the authority of Michigan's Natural Resources and Environmental Protection Act (P.A. 451) and other state laws.
Permittees or other parties may be required to perform WET tests on wastewater effluents to protect lakes and streams from toxic effects. We have compiled a List of Consultants who offer WET testing services. Consultants performing WET tests for Michigan dischargers must provide a rigorous level of Quality Assurance (click here to see "State of Michigan Requirements for Whole Effluent Toxicity (WET) Test Methods").
For ease of reporting and quality assurance, Michigan encourages the use of the following preformatted forms:
- Acute Toxicity Test Report, EQP9308
- Ceriodaphnia Dubia Chronic Toxicity Test Report, EQP9309
- Fathead Minnow Chronic Toxicity Test Report, EQP9310
For additional information on documents and information sources for WET, see the following web sites: