On July 23, 2024, EPA published the National Pollutant Discharge Elimination System (NPDES) Whole Effluent Toxicity (WET) Permit Writers’ Manual, which provides the NPDES permit writer with information and resources that support writing NPDES permit WET requirements. This manual was designed for the NPDES permit writer, whether new to or experienced with the NPDES program, or anyone else interested in learning about the regulatory, programmatic, and technical aspects of developing and implementing WET provisions in an NPDES permit. It summarizes recommendations and requirements for developing NPDES WET permit requirements based on EPA guidance, policy, and regulations, as well as the Clean Water Act.

For any questions related to this announcement, please contact Laura Phillips at (202) 564-0741 or phillips.laura@epa.gov, or Jackie Clark at (202) 564-6582 or [email protected].