Publication Summary

The Water Quality Program Permit Management Section has planned from the beginning to evaluate the implementation of the state′s regulation on Whole Effluent Toxicity (WET). The WET regulation was adopted in October 1993, and we have managed to capture into a database most of the WET tests conducted to meet its requirements. We have also been very active in evaluating the performance of WET tests and have developed a detailed review process for the WET test results. A critical evaluation of the regulatory program involving WET testing seemed possible and desirable in our effort to improve the effectiveness and efficiency of the state′s regulatory programs.

The Water Quality Program Permit Management Section has planned from the beginning to evaluate the implementation of the state′s regulation on Whole Effluent Toxicity (WET). The WET regulation was adopted in October 1993, and we have managed to capture into a database most of the WET tests conducted to meet its requirements. We have also been very active in evaluating the performance of WET tests and have developed a detailed review process for the WET test results. A critical evaluation of the regulatory program involving WET testing seemed possible and desirable in our effort to improve the effectiveness and efficiency of the state′s regulatory programs.

Recent events have made this document more difficult to write. WET is nationally one of the most controversial elements of water quality-based permitting. Concerned representatives have introduced individual bills on the subject of WET alone in congress. Environmental Protection Agency (EPA) has responded by consulting stakeholders and the scientific community, especially the Society of Environmental Toxicology and Chemistry (SETAC). The document is forced by these responses to the national WET controversy to discuss changes that would not necessarily arise out of our own experience with WET in Washington State.

SETAC conducted the Pellston Workshop on WET testing in September 1995, in order to resolve important scientific issues involving the regulatory application of WET testing. In September 1996, EPA hosted the WET Stakeholder′s Meeting to get broader input in developing the Pellston Workshop recommendations into a new strategy for regulating WET. EPA has drafted a new WET implementation strategy in response to Pellston and the Stakeholder′s Meeting that, if followed, would create a complicated regulatory system. This document discusses our experiences with WET and charts potential future courses primarily from a regulatory perspective. Some scientific issues related to the national controversy are explained below in Section V. Supporting Discussions and General Conclusion.