Regulations & Permits > Permits & Certifications > Air Quality permits > Prevention of Significant Deterioration

Prevention of Significant Deterioration (PSD) permit

We issue Prevention of Significant Deterioration (PSD) permits for industrial sources of air pollution in Washington. Some projects are regulated by Energy Facility Site Evaluation Council, EPA, or tribes.

Once issued, final PSD permits remain active unless they are rescinded.


Smokestacks at industrial facility in Washington.

About PSD permits & public comments

A PSD permit applies to new, large facilities or changes at existing large facilities that could increase air pollution in an area.

PSD permits are for projects that significantly increase air pollution. A PSD permit is a "pre-construction permit" because the business owner must get the permit before starting construction of the proposed project. Any major change to existing equipment also requires a PSD permit.

Public comment periods on draft permits are updated on this page.
Draft PSD permits and public comments

Determine if you need a PSD permit

Option A:  If you know your project needs a PSD permit, skip this step. Schedule a pre-application meeting with us.

Option B:  If you want to make sure your project needs a PSD permit:

  1. Fill out an Application for a PSD Applicability Determination (as much as you can).
  2. Schedule a pre-application meeting with us (contact information below) and bring your Application for a PSD Applicability Determination.

For projects regulated by the Energy Facility Site Evaluation Council (EFSEC) or EPA Region 10 on tribal lands, contact those agencies.

Pre-application meeting for a PSD permit

We recommend meeting with Ecology staff before preparing a PSD application. At the pre-application meeting, we will:

  • Coordinate the agencies involved in the project.
  • Discuss your project, the PSD permitting process, and what to include in your application.
  • Review the fee application that you must submit with the fee and project application.
To schedule a pre-application meeting, call or email the contact listed below.

Permitting process

  1. The applicant meets with Ecology and other agencies in a pre-application meeting to discuss the project.
  2. The applicant submits the fee and application with all the necessary technical information.
  3. If all the necessary technical information is included, we consider the application complete. If the application is incomplete, we notify the applicant to submit additional information.
  4. Once the application is complete, we draft a permit.
  5. We open a public comment period.  We may also hold a public hearing, depending on public interest.
  6. We respond to public comments and make changes to the permit as necessary.
  7. If significant changes are made to the permit, we open another public comment period.
  8. If no significant changes are made to the permit, we issue a final permit.
​For more information about the permitting process, refer to the Guidance on Washington's Prevention of Significant Deterioration Permitting Program.