Publication Summary

The Water Quality Program′s Permit Management Section has planned from the beginning to evaluate the implementation of the state′s regulation on Whole Effluent Toxicity (WET) adopted in October 1993. Since then, we have been very active in evaluating the performance of WET tests and have developed a detailed review process for the WET test results. This document summarizes our experience with WET testing and effluent toxicity. It also presents our thoughts on the interaction of regulation and science in controlling toxicity in the state′s waters. If you wish, we have available another version of this document which is twice as long, contains greater detail, and cites references.

The Water Quality Program′s Permit Management Section has planned from the beginning to evaluate the implementation of the state′s regulation on Whole Effluent Toxicity (WET) adopted in October 1993. Since then, we have been very active in evaluating the performance of WET tests and have developed a detailed review process for the WET test results. This document summarizes our experience with WET testing and effluent toxicity. It also presents our thoughts on the interaction of regulation and science in controlling toxicity in the state′s waters. If you wish, we have available another version of this document which is twice as long, contains greater detail, and cites references.

The first three sections of this document provide background and a description of the WET program as it exists today. The fourth section discusses improvements to the implementation of the WET program and offers new strategies for consideration. The fifth section considers various scientific issues involved in WET testing. The last section evaluates the relationship between science and regulation and presents our regulatory philosophy for WET.

Even though our state′s WET program has generated no serious controversy in the last five years, at the national level, WET is one of the most controversial elements of water quality-based permitting. Concerned congressional representatives have introduced individual bills on the subject of WET alone. The Environmental Protection Agency (EPA) has responded by consulting stakeholders and the scientific community, especially the Society of Environmental Toxicology and Chemistry (SETAC). How these discussions will affect our WET program has yet to be seen.