Common Effects Approach for Aquatic Life Protective Values for Pesticides

The U.S. Environmental Protection Agency's Office of Water (OW) and Office of Pesticide Programs (OPP) have been working together for several years to develop a harmonized approach to assess aquatic life effects of pesticides for the purposes of both the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and Clean Water Act (CWA). Effects assessments under the agency’s pesticide and water programs are developed with high quality data according to parallel but somewhat different rigorous and peer-reviewed assessment methods. This collaborative effort within the EPA ensures development of protective aquatic life values using the latest scientific knowledge while minimizing duplicative work within the agency and promoting consistency in aquatic effects assessments for pesticides. OPP pesticide aquatic life benchmarks, developed in support of registration decisions under FIFRA, are currently available for over 750 pesticides and pesticide degradates, and they are routinely updated as new science becomes available. Common aquatic effect values would allow the EPA to leverage the scientific work already completed by one agency program in another program, resulting in the most efficient use of agency resources, while effectively protecting the environment.

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Comparison of Aquatic Life Protective Values Developed for Pesticides under FIFRA and the CWA
Previous Activities for Developing Common Effects Approach for Pesticides

Comparison of Aquatic Life Protective Values Developed for Pesticides under FIFRA and the CWA

These draft analyses compare aquatic life benchmarks developed by the OPP in support of registration decisions under FIFRA to national recommended Ambient Water Quality Criteria and related values developed under the CWA for the protection of aquatic life from pesticides. The EPA’s analyses show that the values developed under these statutes are similarly protective of aquatic life and that OPP aquatic life benchmarks could also serve as CWA aquatic life protective values either as Section 304(a)(1) criteria or Section 304(a)(2) informational benchmarks for pesticides.

The EPA accepted public comments on the draft analyses, Comparison of Aquatic Life Protective Values Developed for Pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Clean Water Act (CWA) (Docket ID no. EPA-HQ-OW-2023-0107) and potential application of OPP aquatic life benchmarks for CWA 304(a) purposes through March 3, 2025 (extended from the original January 27, 2025 deadline).

If the EPA pursues this approach, the agency would undertake subsequent efforts to publish CWA 304(a) aquatic life values for over 750 pesticides that states and Tribes may consider in their water quality protection programs. The CWA 304(a) values would be regularly updated to reflect the latest scientific information submitted under FIFRA and would represent the best available science regarding the aquatic life effects of pesticides.

Previous Activities for Developing Common Effects Approach for Pesticides

The EPA has been working since 2009 to harmonize OPP’s benchmarks and CWA Section 304(a) aquatic life effects assessments in response to states and other stakeholders questioning the differences between these two approaches.

In 2010, the EPA notified the public of multiple stakeholder meetings held when the agency first considered harmonizing aquatic effects assessments for pesticides under the FIFRA and the CWA (EPA-HQ-OPP-2009-0773).

In 2011, the agency solicited public comments as part of the 2012 FIFRA Scientific Advisory Panel (SAP) review of the EPA analyses regarding potential approaches (EPA-HQ-OPP-2011-0898). The SAP made recommendations to develop an approach to harmonize OPP’s benchmarks and CWA Section 304(a) aquatic life criteria recommendations. The EPA focused on comparing the relative magnitude of the values derived using the respective FIFRA and CWA methods to examine whether the different effects assessment approaches yield similar results.