Section 401 of the Clean Water Act

Section 401 Certification

The Clean Water Act gives states and authorized Tribes the authority to grant, deny, or waive certification of proposed federal licenses or permits that may discharge into waters of the United States.
Memorandum on the Scope of Certification

On May 21, 2025, EPA issued a memorandum that clarified the significant but limited role that states and Tribes play in the federal licensing and permitting processes under Clean Water Act Section 401. The direction provided in this memorandum reflects the existing requirements of the agency’s CWA section 401 certification rule issued in 2023, without changes or updates.
Read the Memo

Section 401 Background

Overview of Section 401

Clean Water Act Section 401 requires certification before a federal agency issues a permit or license that may result in discharge into waters of the United States.

Learn more about Section 401 certification
Regulatory Requirements

Clean Water Act Section 401 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.

Learn more about the requirements
Outreach Opportunities

EPA conducts outreach and engagement efforts to ensure effective implementation of Clean Water Act Section 401.

Learn more about EPA's engagement

The EPA has developed several resources to help implement certification and post-certification processes.

Technical Assistance

EPA is responsible for providing technical assistance upon request from Federal agencies, certifying authorities, or Federal license or permit applicants.

Technical Assistance Resources
EPA as a Certifying Authority

EPA may act as a certifying authority where a state or authorized Tribe does not have authority to certify.

EPA as a Certifying Authority Resources