Why do I need a State Water Quality Certification, CWA Section 401?

This certification is for state issuance of a State Water Quality Certification (401 WQC) for an activity or project requiring a federal permit or license, that may result in a discharge to waters of the U.S.

States are given the authority to issue WQC’s through Section 401 of the Clean Water Act (CWA). Under §401, a federal agency cannot issue a permit or license until/unless the state has certified, conditionally certified, waived, or denied the 401 WQC. Issuing a WQC ensures that the project will not violate surface water quality standards. The WQC becomes a part of the federal permit or license and is valid for the same time period as the permit or license, often issued for five-year terms.

The U.S. EPA’s 401 Rule [Title 40 Part 121]

The Environmental Protection Agency (EPA) published a final rule to update and clarify the substantive and procedural requirements for water quality certification under CWA section 401. This rule became effective on Sept. 11, 2020. One significant change to this rule is the “Pre-filing Meeting Request Requirement." All applicants must submit a request for a meeting with the appropriate certifying authority (ADEQ) at least 30 days prior to submitting a certification request. The meeting request provides advance notification to the certifying authority that a certification request may be forthcoming. Prior to compleing CWA 401 applications, please contact Rosi Sherrill | Email >

Applicants are also encouraged to review the new rule requirements prior to submitting a certification request | Visit EPA CWA Section 401 Webpage >

When do I need a CWA401 Water Quality Certification?

1. If the U.S. Army Corps of Engineers (USACE) permit is a Nationwide or Regional General Permit:

a. A 401 WQC application submission to ADEQ is required if the certified activities of the project discharge within the Ordinary High Water Mark of a Water of the US (WUS) that is:

  • An Outstanding Arizona Water
  • An Impaired Water
  • A Not Attaining Water
  • A Lake

b. A 401 WQC application submission to ADEQ is not required if the WUS doesn’t meet the conditions in #1. The certified activities of the project are conditionally certified under the USACE Nationwide Permit and the Regional General Permits.

2. If the USACE is an Individual permit to the USACE or any other Federal Agency:

a. A 401 WQC application submission to ADEQ is required.

Updated CWA 401 Forms

ADEQ has revised our 401 WQC application. In order to reduce our customers processing time, ADEQ has eliminated the need for a full application on projects with the USACE. We have provided applications for Nationwide and Individual permits, which can be submitted with the completed USACE form (PCN/Concurrence/Eng. 4345) and associated documentation.

  • Application Form for State Certification of Activities Requiring a U.S. Army Corps of Engineers General or Nationwide Permit | Download Application >
  • Application Form for State Certification of Activities Requiring a U.S. Army Corps of Engineers Standard Individual Permit1Download Application >

ADEQ has also revised the 401 WQC Application to other Federal permits.

  • Application Form for State Certification of Activities Requiring a Federal License or Permit (not Corps) | Download Application >

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