CWA Section 401 Regulatory Requirements
On this page:
- Overview
- Current Regulatory Requirements
- Outreach Materials
- Frequently Asked Questions
- Previous Regulatory Requirements
New Engagement Opportunity
On July 1, 2025, the agency announced a Federal Register notice initiating a series of stakeholder listening sessions and a 30-day recommendations docket inviting written feedback on regulatory uncertainty or implementation challenges associated with the Clean Water Act section 401 certification process as defined in the 2023 Rule.
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. EPA's current regulations at 40 CFR 121 address 401 certification generally.
The final Clean Water Act Section 401 Water Quality Certification Improvement Rule went into effect on November 27, 2023. The final rule and supporting documents, including outreach materials, are provided below.