CWA Section 401 Regulatory Requirements
Overview
Section 401 of the Clean Water Act provides states and authorized Tribes with an important tool to help protect the water quality of federally regulated waters within their borders, in collaboration with federal agencies.
Proposed Rule
On January 13, 2026, the EPA announced a proposed rule to revise the existing Section 401 water quality certification regulations. Once the proposed rule is posted in the Federal Register, EPA will accept public comments on the proposed rule. Comments on the notice should be identified by Docket ID No. EPA-HQ-OW-2025-2929 and may be submitted online. Go to https://www.regulations.gov and follow online instructions for submitting comments to the docket.
Rule Materials
- CWA 401 Preamble (pdf) (Docket ID No. EPA-HQ-OW-2025-2929)
- CWA 401 Economic Analysis (pdf)
Rule Outreach Materials
Pre-Proposal Input
Frequently Asked Questions
Why is EPA proposing a new rule? Why not just leave in place the 2023 Rule on the same topic?
- This proposed rule would revise several procedural and substantive aspects of the current regulations to increase transparency, efficiency, and predictability for certifying authorities and the regulated community, better align the regulations with the text and legislative history of the Clean Water Act, and to ensure states and authorized tribes understand and adhere to their section 401 role.
How long is the public comment period?
- The Agency will accept comment on the proposed rule for 30 days upon publication in the Federal Register.
Where can stakeholders submit comments?
- Stakeholders may submit comments online at https://www.regulations.gov to Docket ID No. EPA-HQ-OW-2025-2929.
Will there be any public outreach during the public comment period?
- Yes. The Agency will host a virtual public meeting on the proposed rule in January 28, 2026. Please see EPA’s section 401 website for more information about outreach efforts.
When will the rule be finalized?
- The Agency intends to finalize the rule in Spring 2026.
Current Regulatory Requirements
EPA's current regulations at 40 CFR 121 address 401 certification generally.
Rule Materials
- Memorandum on the Scope of Certification (pdf)
- 2023 Clean Water Act Section 401 Water Quality Certification Improvement Rule
- Response to Comments
- Economic Analysis
- Regulations (40 CFR 121)
- Proposed Rule
Rule Outreach Materials
- One-Page Fact Sheet on the Final Rule (English | Spanish)
- Overview Fact Sheet on the Final Rule (English | Spanish)
- Frequently Asked Questions (English)
- Presentations and Webinars
- Rule Overview (Video | Slides)
- Implementation Considerations (Video | Slides)
- General Public Webinar (Video | Slides) (Recorded on September 26, 2023)
- Section 401 & Treatment in a Similar Manner as a State (TAS) Webinar (Video | Slides) (Recorded on October 17, 2023)
- Certifying Authority Webinar (Video | Slides) (Recorded on September 28, 2023)
- Federal Agency Webinar (Video | Slides) (Recorded on October 3, 2023)