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CWA Section 401 Certification
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Overview of CWA Section 401 Certification

Under Section 401 of the Clean Water Act (CWA), a federal agency may not issue a permit or license to conduct any activity that may result in any discharge into waters of the United States unless a Section 401 water quality certification is issued, or certification is waived. States and authorized tribes where the discharge would originate are generally responsible for issuing water quality certifications. In cases where a state or tribe does not have authority, EPA is responsible for issuing certification. 33 USC 1341. Some of the major federal licenses and permits subject to Section 401 include:

  • Clean Water Act Section 402 and 404 permits issued by EPA or the Corps,
  • Federal Energy Regulatory Commission (FERC) licenses for hydropower facilities and natural gas pipelines, and
  • Rivers and Harbors Act Section 9 and 10 permits.

The CWA provides that certifying authorities (states, authorized tribes, and EPA) must act on a Section 401 certification request "within a reasonable period of time (which shall not to exceed one year) after receipt" of such a request. A certifying authority may waive certification expressly, or by failing or refusing to act within the established reasonable period of time. In making decisions to grant, grant with conditions, or deny certification requests, certifying authorities consider whether the federally-licensed or permitted activity will comply with applicable water quality standards, effluent limitations, new source performance standards, toxic pollutants restrictions and other appropriate water quality requirements of state or tribal law.

A federal agency may not issue a license or permit for an activity that may result in a discharge into a water of the United States without a water quality certification or waiver.

  • Read Clean Water Act Section 401

Regulatory Requirements for CWA Section 401 Certification

Section 401 of the Clean Water Act (CWA) 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 regulations at 40 CFR 121 address Section 401 certification generally. EPA also has water quality certification regulations for federally-issued CWA Section 402 permits that are subject to the Section 401 certification requirements (40 CFR 124.53-124.55 (PDF)). Other federal agencies may also have CWA section 401 certification regulations for their licensing and permitting programs.

On April 6, 2022, the U.S. Supreme Court issued a stay of the October 2021 order by the U.S. District Court for the Northern District of California that vacated EPA’s 2020 Clean Water Act Section 401 Certification Rule (2020 Rule). The stay of the vacatur applies nationwide. Therefore, the CWA section 401 certification process is once again governed by the CWA section 401 certification regulations promulgated by EPA in 2020 and codified at 40 CFR 121. 

  • 2020 CWA Section 401 Certification Rule
  • 1971 EPA regulations for Section 401 (PDF)

Please refer to the EPA Archive for the rescinded 2010 Clean Water Act Section 401 Handbook and the rescinded 2019 Guidance on CWA Section 401.

  • Section 401 Certification Home
    • Basic Information on Section 401 Certification
    • Read Section 401
  • Proposed Clean Water Act Section 401 Water Quality Certification Improvement Rule
  • Outreach and Engagement on CWA Section 401 Certification
  • 2020 Clean Water Act Section 401 Certification Rule
    • Q&A on the Stay of the 2020 Rule Vacatur
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on April 22, 2022
United States Environmental Protection Agency

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