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Air Quality Program

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Prevention of Significant Deterioration (PSD) Permits Information

This web site is intended for those seeking information about what to expect from the Prevention of Significant Deterioration (PSD) permitting process.

PSD permits are for projects that may significantly increase air pollutant emissions. The Washington Department of Ecology (Ecology) prepares PSD permits for industrial sources of air pollution (see EPA-Ecology delegation agreement link) except for projects involving Washington's Energy Facility Site Evaluation Council (EFSEC).

This web page includes information on PSD permits that are being or have been drafted by Ecology, comment and appeal procedures, and information intended to help PSD permit applicants. See the links at the left.

The permitting process is as follows:

  • The owner or operator of the facility meets with Ecology and others to discuss what to include in the application regarding methodologies for dispersion modeling, and how to determine what Best Available Control Technology (BACT) to use to minimize pollutant emissions.
  • The applicant submits an application that contains all the necessary technical information to determine:
    • what level of control technology and emission limitations constitute BACT; and
    • that the pollutant emissions will not significantly impact the environment.
  • Ecology drafts a permit that we believe satisfies all regulatory requirements.
  • Ecology releases the draft permit and a technical fact sheet for a 30-day public review and comment period. Electronic copies of draft permits and related fact sheets are posted on Ecology’s web site “Prevention of Significant Deterioration Permits (PSDs) Open for Public Comment ”.
  • At the end of the comment period, Ecology makes relevant changes to the draft permit in response to any public comments received; drafts a responsiveness summary for the comments; and issues a final permit. The final permit and responsiveness summary are posted on the PSD web site “Prevention of Significant Deterioration Final Permits”.

Please note:

Certain electric power generation projects are under the jurisdiction of the Washington Energy Facility Site Evaluation Council (EFSEC). These sources must contact EFSEC for information. EFSEC maintains a separate Internet site for accessing information regarding the sources under its jurisdiction.

Comments on any PSD permits that are open for public comment can be mailed to the indicated Ecology contact, Washington Department of Ecology, P.O. Box 47600, Olympia, WA 98504-7600.

Related Links

Contact Us


Application for a Prevention of Significant Deterioration Applicability Determination

Updating New Source Review Fees in Chapter 173-455 WAC

Governor's Office of Regulatory Assistance