Clean Water Act — Section 401 Water Quality Certifications

Passed by Congress in 1972, the federal Clean Water Act grants states and tribal governments the authority to approve, condition, or deny proposed projects, actions, and activities directly affecting waters of the United States.

Under Section 401 of the Clean Water Act, federal agencies cannot issue a license or permit before a state makes a determination on a water quality certification request. Any conditions state or tribal governments set then become conditions of a federal permit or license.

Please note: The Section 401 Certification process has changed as of Sept. 11, 2020. See the alert box for the most up-to-date information.

We use our Section 401 authority to set conditions for projects, actions, and activities that can affect water quality in Washington. For example:

  • When a port seeks permission to dredge a channel or waterway, we outline where sediment spoils can go.
  • When hydropower dams request a license for an existing dam or for new construction, we assess whether state water quality standards can be met and set conditions to ensure state waters are protected.     
  • We set standards to protect wetlands during site development, and determine when mitigation or enhancements are necessary.
  • Shoreline property owners wanting new piers and other structures follow our certification conditions to minimize water quality and environmental impacts.

When we issue a Section 401 water quality certification, it means that we have determined a project or action, as proposed and conditioned, will comply with state water quality standards and other requirements to protect state aquatic resources.

Certifications for state hydropower licenses

We work with the Federal Energy Regulatory Commission (FERC) licensing process for hydropower dams. When an applicant requests a license, either to re-license an existing dam or for new construction, we work with the utility and review studies, analyses, and plans. If we determine that water quality standards are attainable, a 401 certification is issued with conditions to ensure that the standards will be met. These conditions become part of the new FERC license.

Non-hydropower Section 401 Certifications

Washington's Section 401 Certifications provide a strong opportunity to protect and enhance water quality, aquatic species and habitats, water resources, coastal resources, floodplains, and other environmental elements.

Certifications for NPDES federal permits

National Pollutant Discharge Elimination System (NPDES) permits limit the quality and quantity of wastewater discharge into surface waters like rivers, lakes, and streams. We write NPDES permits for all non-federal discharges in the state, except those on tribal lands.

Recent 401 certifications for large energy projects