Research Areas > Contaminants > Toxicity Assessment and Identification > Whole Effluent Toxicity

Project: Development of Whole Effluent Toxicity Implementation Guidance

Background and Objectives

Whole Effluent Toxicity (WET) tests estimate the potential effects of wastewater discharge on the survival, growth, and reproduction of aquatic species. They work by exposing sensitive organisms to wastewater effluent or receiving waters in order to monitor the aggregate effects of toxicants.

WET tests are used to determine compliance with the toxicity objectives established in California’s Regional Water Quality Control Plans (Basin Plans). The State Water Resources Control Board (State Water Board) is currently revising the toxicity control provisions set forth in the 2005 State Implementation Policy (SIP) called Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California. Their proposed changes include standardization of WET test provisions for National Pollutant Discharge Elimination System (NPDES) permittees and other applicable dischargers.

The goal of this project is to assist the State Water Board by developing training and technical guidance materials to support implementation of a revised WET policy. The project includes four main objectives:

1. Obtain test performance data for WET species;
2. Develop implementation guidance for application of WET tests in stormwater discharge permits;
3. Provide technical review of implementation documents; and
4. Assist with training on the new implementation methods.

Status

This is project was initiated in 2010 with anticipated completion in 2011.

Methods

Implementation of the new toxicity control provisions by the State will require several types of technical support. These include compilation of California test species data and method refinement to support adaptation of data analysis methods to west coast species. SCCWRP will also develop guidance for stormwater WET testing in coordination with the Stormwater Monitoring Coalition and other agencies involved in stormwater testing and management. Document review and training assistance will be provided as needed to support the project objectives.

Partners

This project is being conducted in collaboration with the Southern California Stormwater Monitoring Coalition and the State Water Resources Control Board. Funding for this project has been provided in part by the American Recovery and Reinvestment Act of 2009, from the US EPA and the California State Water Resources Control Board.