Base
Proposed RuleSignificantOpen for Comment2026-183172026-09-09

Updated Definition of “Waters of the United States”

Defense Department, Engineers Corps, Environmental Protection Agency

Abstract

The purpose of this supplemental notice of proposed rulemaking is for the U.S. Environmental Protection Agency (EPA) and the Department of the Army ("the agencies") to supplement and seek additional comment on certain aspects of an earlier proposal, published on November 20, 2025, to revise the regulations defining the scope of waters federally covered under the Clean Water Act in light of the U.S. Supreme Court's 2023 decision in Sackett v. Environmental Protection Agency. As stated in the agencies' November 20, 2025 Notice of Proposed Rulemaking (NPRM), the agencies intend for this rulemaking to provide greater regulatory certainty and increase Clean Water Act program predictability and consistency by clarifying the definition of "waters of the United States." After consideration of the public comments received on the NPRM, the agencies are issuing this notice to supplement the NPRM with additional regulatory options on certain aspects of the proposed rule.

Action & Dates

Action
Supplemental notice of proposed rulemaking.
Dates
Comments must be received on or before October 9, 2026.

CFR References

Topics

Administrative practice and procedureEnvironmental protectionNavigation (water)Water pollution controlWaterways

Public Comment

Comments Close
2026-10-09 — Open for comment

Document Excerpt

Document Headings Document headings vary by document type but may contain the following: the agency or agencies that issued and signed a document the number of the CFR title and the number of each part the document amends, proposes to amend, or is directly related to the agency docket number / agency internal file number the RIN which identifies each regulatory action listed in the Unified Agenda of Federal Regulatory and Deregulatory Actions See the Document Drafting Handbook for more details. Department of Defense Department of the Army, Corps of Engineers 33 CFR Part 328 Environmental Protection Agency 40 CFR Part 120 [EPA-HQ-OW-2025-0322; FRL 11132.1-04-OW] RIN 2040-AG44 AGENCY: Department of Defense, Department of the Army, Corps of Engineers; U.S. Environmental Protection Agency (EPA). ACTION: Supplemental notice of proposed rulemaking. SUMMARY: The purpose of this supplemental notice of proposed rulemaking is for the U.S. Environmental Protection Agency (EPA) and the Department of the Army (“the agencies”) to supplement and seek additional comment on certain aspects of an earlier proposal, published on November 20, 2025, to revise the regulations defining the scope of waters federally covered under the Clean Water Act in light of the U.S. Supreme Court's 2023 decision in Sackett v. Environmental Protection Agency. As stated in the agencies' November 20, 2025 Notice of Proposed Rulemaking (NPRM), the agencies intend for this rulemaking to provide greater regulatory certainty and increase Clean Water Act program predictability and consistency by clarifying the definition of “waters of the United States.” After consideration of the public comments received on the NPRM, the agencies are issuing this notice to supplement the NPRM with additional regulatory options on certain aspects of the proposed rule. DATES: Comments must be received on or before October 9, 2026. ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-OW-202

Read full document on FederalRegister.gov →

Related Documents

Other Federal Register documents from the same docket.

Full Document

Citation: 91 FR 57284