Prevention of Significant Deterioration (PSD) Air Quality Permit

What is the purpose of this permit?
The Prevention of Significant Deterioration (PSD) permit was developed to prevent significant environmental impacts on air quality from large industrial sources of air pollution. The permit applies to new or modified air pollution sources that are classified as “major” relative to air pollution emissions potential, and that are proposing construction projects that may “significantly” increase their air pollutant emissions.

Under the PSD program, the projects demonstrate that they are designed in a way to ensure compliance with air quality regulations that protect human health and the environment. The PSD application process is complex and requires applicants to conduct engineering evaluations and computer modeling to demonstrate the proposed project will meet air quality standards.
Who issues this permit?
Department of Ecology
What activities require this permit?
A facility with a new major source of air pollution with the potential to emit a pollutant regulated under the Federal Clean Air Act at 100 tons/year for 28 specific emission source types, or 250 tons/year or more for all other emission source types.

A modification of an existing major source of air pollution that increases emissions of a pollutant regulated under the Federal Clean Air Act at or above PSD Significant Emission Rates (SER).

If you are not sure if your activity requires this permit you can request a PSD program applicability review. An applicability determination has a $500 fee.
How much will this permit cost?
The fees for applying for a PSD new or modified permit vary depending on the type of project. The following document “New Air Quality Permitting Fees Effective July 2011” provides more specifics about fees:
Where can I get the application for this permit?
The application is called 'Application for a Prevention of Significant Deterioration Applicability Determination' is online and can be accessed at
Do I need to include anything with my application?
A PSD application typically contains the following information:
  • Process description.
  • Operational limits.
  • Best Available Control Technology (BACT).
  • Allowable emission rates.
  • Results of on-site measurements.
  • Results of air quality impact modeling.
  • Results of air-quality-related values (AQRV) assessment, such as impacts on national parks and wildlife areas.
  • All emissions calculations
Ecology recommends the source schedule a pre-application meeting to provide guidance on what specifically needs to be included in the PSD application for the proposed project.
Is the decision on my permit dependent on anything besides the information in my application?
The State Environmental Policy Act (SEPA) and EPA consultation on impacts related to the Endangered Species Act (ESA) and Historical Preservation Acts (HPA) must be complete before the permit can be issued. These processes occur outside of the PSD process.
How long will it take to review my application?
The minimum time period is 120 days:
  • 30 days for completeness determination.
  • 60 days for permit writing.
  • 30 days for public comment.
Ecology will inform permit applicants in writing whether their application is complete within 30 calendar days of receipt. After receiving a complete application, Ecology issues a draft PSD permit and Technical Support Document (TSD). These are distributed and Ecology holds a 30-day public comment period. All interested parties may submit written comments on the draft PSD permit. Ecology will review the comments and determine if a public hearing is necessary. If a hearing is held, Ecology will hear testimony from the interested parties before issuing a decision. An administrative PSD amendment does not require a public comment period. Final PSD permit determinations will be issued as promptly as possible after the public comment period is closed.
Where do I submit my application?
The application is submitted to:

    Washington State Department of Ecology
    Air Quality Program
    Science and Engineering Section
    P.O. Box 47600
    Olympia, Washington 98504-7600
View the schematic
How long is my permit valid?
Once issued the permit does not expire unless cancelled by the applicant.
What is the appeal process for the permit?
You have a right to appeal this PSD permit to the Pollution Control Hearings Board (PCHB) within 30 days of the date of receipt of the permit. The appeal process is governed by Chapter 43.21B RCW and Chapter 371-08 WAC. “Date of receipt” is defined in RCW 43.21B.001(2). You must also comply with other applicable requirements in Chapter 43.21B RCW and Chapter 371-08 WAC.
Legal Authority:
Permit Timeliness Results

Permit Timeliness data collection is in response to a State Auditor’s Performance Audit and RCW 43.42A. Each regulatory agency developed a plan to improve permit clarity, predictability, and timeliness. Each agency considers the customers experience to ensure permit assistance is simple to use, easy to access, and designed in a customer-friendly manner. Agencies report progress to the Governor’s Office for Regulatory Innovation and Assistance (ORIA). ORIA prepares and distributes reports, with participation from the State Auditor’s Office and Results Washington. See latest report here:

All permits submitted for reporting were entered into this Regulatory Handbook. Here are the results of the performance data:

Estimated Time Required By the Agency to Process a Permit Application (Definition)
Average number of days from Receipt to Complete: 29
Maximum number of days from Receipt to Complete: 29

Estimated Time Required By the Agency to Issue a Permit Decision (Definition)
Average number of days from Complete Application to Decision: 29
Maximum number of days from Complete Application to Decision: 29

(Summary results based on 1 submittals in 2023)

Where can I get permitting assistance?
Web page URL:
Subject matter expert phone: Christopher Hanlon-Meyer: (360) 407-6115
Subject matter expert email: Christopher Hanlon-Meyer:
Department of Ecology
Air Quality Program
300 Desmond Drive
PO Box 47600
Olympia, WA 98504-7600
Telephone: (360) 407-6800
Fax: (360) 407-7534
Triggering Questions:
  • Are you a Major Source with a project that significantly increases air pollutant emissions?
* Permit information last updated 8/13/2019