On September 9, 2026, the Environmental Protection Agency (EPA) and the U.S. Army Corps of Engineers released a Supplemental Notice of Proposed Rulemaking (SNPRM) seeking further comment on the November 2025 proposed rule to update the definition of “Waters of the United States” (WOTUS).
The agencies seek comment on definitions such as “perennial,” “relatively permanent,” and “continuous surface connection,” definitions that determine the scope of Clean Water Act (CWA) regulatory programs. The definitions of these terms as presented in the 2025 proposed rule would reduce the scope of waters protected under the Clean Water Act. Comments on the SNPRM are due October 9, 2026.
The Environmental Data & Governance Initiative (EDGI) opposes the regulatory alternatives presented in the SNPRM, arguing that the SNPRM’s lack of incorporation of widely accepted science as well as EPA’s information removals both undermine the Clean Water Act, which legally requires the use of the best available science in proposed rules that establish federal jurisdiction. Specifically, EDGI’s public comment notes that:
- The definition options in the SNPRM do not appropriately address the impacts of climate change on hydrology and are too narrow in outlining what constitutes jurisdictional waters. The elimination of water bodies covered under the Clean Water Act as proposed will have significant implications for water quality, undermining the goals of the Clean Water Act to restore and maintain the “chemical, physical, and biological integrity of the Nation’s waters” (Clean Water Act Section 101 (a)).
- Information removals on federal websites hamper the public’s ability to provide public comments on this SNPRM. In particular, EPA removed its 20-Watersheds Interactive Tool in July 2025, undermining the public’s ability to analyze the impacts of climate change on water quality and prevents fully informed public comments on this SNPRM.
Read EDGI’s full public comment below:
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