By: Abby Chernila, Izzy Pacenza, Gretchen Gehrke, Shannan Lenke Stoll
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.
As EDGI discussed in its public comment on the 2025 proposal, narrowing the scope of jurisdictional waters has significant negative consequences for water quality. Surface waters accumulate hazardous chemicals as they flow downstream and receive contaminated tributaries and other surface and subsurface outflows. Narrowing the scope of jurisdictional waters removes those waters from EPA’s regulatory programs under the CWA.
The 2025 proposed rule is based on the 2023 Sackett v. EPA Supreme Court interpretation based on an opinion by Antonin Scalia. Scalia’s opinion narrows the scope of jurisdictional waters to only those that are “relatively permanent” and with “continuous surface connection.” The 2025 rule and the opinion it’s based on disregard long-established hydrology and would exclude many hydrologically connected waters from those that are considered jurisdictional.
Further, the 2025 rule does not account for climate change’s impacts on water flow during wet and dry seasons, including worsening drought conditions in arid regions of the U.S. Definitions of “perennial” and “continuous surface connection” in the proposed rule would increasingly eliminate more water bodies from being covered under the CWA over time as climate change creates drier conditions.
Adopting these scientifically unsound definitions of jurisdictional waters chips away at the authority of the CWA, leaving room for greater, unmonitored contamination and pollution in water bodies that would no longer be covered, increasing risks to human and environmental health.
Public Comments Matter
This SNPRM demonstrates why public comments matter. The SNPRM states that during the 2025 proposed rule’s initial commenting period, 220,000 comments were received. The SNPRM then asks for additional comments based on the exact issues raised during that initial commenting period—namely, unclear definitions and regulatory options. Specifically, the SNPRM states that many “commenters requested additional clarification regarding the agencies’ proposed rule and the alternative approaches for which the agencies solicited comment,” and “supplemental regulatory options were developed based on the agencies’ analysis of the public comments and stakeholder input received on the proposed rule.”
Public comments are helping to slow down this administration’s unravelling of the CWA. Public comments that question vague and unscientific definitions pressure agencies to pause and respond. EDGI encourages you to continue to share your voice and concerns on a rule that would have critical implications for human and environmental health. Scientifically sound definitions of “Waters of the United States” are necessary to prevent ever growing acres of wetlands and water bodies from being polluted with no action from the EPA.
Public Comment Resources
View EDGI’s Guide for writing a public comment on this rule here: Information Packet.
Submit your public comment here: Submission Portal. And follow EDGI on Bluesky and LinkedIn for announcements of more resources (including workshops) on this and other proposed environmental rules.