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 Certification) 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 this certification 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 or waived the 401 Certification. Issuing this certification ensures that the project will not violate surface water quality standards, adversely impact impaired waters (waters that do not meet water quality standards) and that the project complies with applicable water quality improvement plans (total maximum daily loads). This certification becomes a part of the federal permit or license. The certification is valid for the same time period as the permit or license, often issued for five-year terms.

When do I need a CWA401 Water Quality Certification?

1. If the 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.


  1. 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 an Application Cover Sheet, which can be submitted with the completed USACE form (PCN/Concurrence/Eng. 4345) and associated documentation (see link below).
  2. ADEQ has also revised the 401 WQC Application to other Federal permits (see link below).
  3. On individual permits, the completed Application Cover Sheet and USACE application should not be submitted to ADEQ until the USACE has reviewed the information and published the project through the Public Notice Process. Please contact Rosi Sherrill for pre-application discussions.

State Water Quality Certification, CWA Section 401 for a USACE CWA 404 Permit | Download Application >
State Water Quality Certification, CWA Section 401 for a Federal Agency Permit (non-CWA404) | Download Application >

For questions, contact:
Rosi Sherrill
Email >