Clean Water Act — Section 401 Water Quality Certifications

In Sept. 2020, the U.S. Environmental Protection Agency (EPA) implemented a Clean Water Act Section 401 Certification Rule under the 1972 federal Clean Water Act. This federal rule has changed the process for submitting requests for Section 401 water quality certifications. To learn how this may affect your business or project, please carefully read and follow the instructions on this page.

As the clean water certifying agency, Ecology has the authority in Washington state under Section 401 of the U.S. Clean Water Act to review and approve, approve with conditions, or deny proposed projects, actions, and activities directly affecting waters of the United States. Tribal governments and EPA also have this authority on tribal and non-state lands.

Under Section 401 of the Clean Water Act, federal agencies cannot issue a license or permit before we make a determination on a water quality certification request or waive our right to review. Any conditions that the certifying agency sets then become conditions of the federal permit or license.

Requesting a 401 water quality certification

Under the EPA's rule, all project proponents requesting a a Section 401 water quality certification must first file a pre-filing meeting request with Ecology at least 30 days before submitting a 401 request. We have three different water quality certification processes based on the type of project. However, effective Sept. 11, 2020, all requests must follow the steps below to begin the 401 water quality certification review and decision process.

To comply with EPA's rule:

  • Before submitting a Section 401 certification request, please request a pre-filing meeting with Ecology at least 30 days beforehand. We have developed a pre-filing request form to assist applicants.
  • At least 30 days after submitting a pre-filing meeting request, applicants may then submit their entire Section 401 request, along with a 401 Request Form, to Ecology and the federal permitting agency.
  • All Section 401 requests must meet the federal requirements in this table.

Applicants must submit their pre-filing meeting requests, Section 401 water quality requests, and any supporting documents to us electronically at

If you are having any difficulties accessing or using these forms, please contact our Federal Permits Unit at or 360-407-6076.

Please note: We are still working to fully understand how EPA's new rule affects the state review processes for Section 401 requests. We will be updating our web content and sending notifications as we work to comply with the new rule.

Examples of projects requiring 401 water quality certification

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 dredge spoils can go.
  • When hydropower projects request a license for an existing dam or for new construction, we assess whether state water quality standards are met and set conditions to ensure state waters are protected.     
  • We review projects with proposed wetland impacts to protect them during site development, and to determine when mitigation is necessary.
  • When shoreline property owners propose new piers and other structures, we work with them to protect water quality and minimize environmental impacts.

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

Certification for specific federal permits and licenses

FERC hydropower licenses

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

US Army Corps of Engineers permits

All projects affecting navigable and protected waters in Washington state, as defined by the federal government, are subject to Section 401 water quality certification. These waters include coastal and marine environments, rivers, streams, lakes, wetlands, etc. This provides a strong opportunity to protect and enhance water quality, aquatic species and habitats, water resources, coastal resources, floodplains, and other environmental elements. This process excludes hydropower and NPDES-related projects.

EPA and Tribal permits

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

Non-federally regulated waters

Washington state defines state waters separate from the federal government. Projects affecting state waters that do not fall under the federal jurisdiction of "waters of the United States" are not subject to federal 401 water quality certification. However, they are still subject to applicable state water quality and environmental protection laws. This may include ponds, wetlands, ephemeral streams, etc. that do not meet the definition of "waters of the United States."

Recent Section 401 decisions and public notices

All public notices for Section 401 water quality certification and our recent decisions are listed in our reporting databases. Information about for notable Section 401 submissions and decisions are also detailed below.

Notable 401 decisions and requests