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This is not the current EPA website. To navigate to the current EPA website, please go to www.epa.gov. This website is historical material reflecting the EPA website as it existed on January 19, 2025. This website is no longer updated and links to external websites and some internal pages may not work. More information »

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Section 401 of the Clean Water Act

  • Section 401 Certification

    The Clean Water Act (CWA) 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. Learn more about 401 certification.

CWA Section 401

  • Overview of Section 401
  • Read Section 401

About the Process

  • Final 2023 Clean Water Act Section 401 Water Quality Certification Improvement Rule
    • Questions and Answers
    • 2023 Rule Presentation Materials
  • Treatment in a Similar Manner as a State for Section 401
  • Treatment in a Similar Manner as a State for Section 401(a)(2)
  • Resources when EPA acts as the Certifying Authority
  • Clean Water Act Section 401(a)(2) Overview

Press Releases

  • EPA Issues Final Rule to Strengthen Water Protections, Support Clear and Timely Reviews of Infrastructure and Development Projects (September 2023)
Contact Us about CWA Section 401 Certification to ask a question, provide feedback, or report a problem.
Last updated on January 13, 2025
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