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WA · EPA Region 10

Washington Air Permits

Washington splits air permitting among Ecology, seven local clean air agencies, EFSEC (large energy facilities), and EPA Region 10 (Indian Country and the Outer Continental Shelf). Ecology issues permits in counties without a local agency and for pulp mills, aluminum mills, and Hanford statewide, and it issues all PSD permits not under EFSEC, EPA, or tribal jurisdiction. Before installing or modifying a source, a business needs a Notice of Construction (NOC) order of approval unless exempt under WAC 173-400-110; toxic air pollutant emitters may need a health impact assessment (WAC 173-460). General orders cover common source types. Major sources need an Air Operating Permit (Title V, WAC 173-401). Most permitted industrial sources must also join the registration program and pay annual fees.
Verified against agency sourceLast reviewed 2026-10-25

Air permits & authorizations

  • NOC exemptions

    Exemption

    Whether an NOC is needed depends on the equipment or its emission levels; exemptions and exemption levels are in WAC 173-400-110.

    WAC 173-400-110Official page

  • Registration program

    Registration / Notice

    Most companies with an industrial air permit must register and pay a yearly fee based on permitted emissions.

    Official page

  • General Orders of Approval

    General Permit

    Ecology general orders for asphalt plants, auto body shops, concrete batch plants, small perchloroethylene dry cleaners, rock crushers, and small water heaters and steam-generating boilers (in Ecology-jurisdiction counties). Portable plants with a valid local agency permit notify Ecology at least 15 days before working in an Ecology county.

    Thresholds (summarized from source, not a quotation)

    Dry cleaners using less than 2,100 gallons of perchloroethylene per year (restated from Ecology).

    WAC 173-400-560Official page

  • Notice of Construction (NOC) Order of Approval

    Minor NSR

    Pre-construction permit required before installing or modifying an air pollution source (new businesses, replacing or changing control equipment, or increasing emissions). May require a SEPA checklist and a health impact assessment for toxic air pollutants. Ecology charges hourly or complexity-based fees (hourly rate $141 for 2026).

    WAC 173-400-110; WAC 173-460Official page

Major NSR (PSD & nonattainment)

  • Prevention of Significant Deterioration (PSD)

    PSD

    For new large facilities or changes at existing large facilities that could increase air pollution. Ecology issues PSD permits statewide except for projects regulated by EFSEC, EPA, or tribes.

    Official page

  • Nonattainment NSR

    Nonattainment NSR

    Issued by Ecology or the local clean air agency with jurisdiction (per EPA).

    Official page

Title V operating permits

  • Air Operating Permit (AOP)

    Title V

    Apply 12 months before the business has the potential to emit the threshold amounts; renewals 6 to 18 months before expiration; 5-year term. Businesses below thresholds may still need an AOP under federal NSPS/NESHAP. Fees based on emissions and permit category.

    Quoted verbatim from the agency source
    More than 100 tons per year of any air pollutant. More than 10 tons per year of any hazardous air pollutant. More than 25 tons per year of a combination of hazardous air pollutants.
    Chapter 173-401 WACOfficial page

Oil & Gas

Washington has no meaningful oil and gas production program in Ecology's air permitting pages. Refineries and large energy facilities are handled through NOC/AOP permits by the local agency, Ecology, or EFSEC.

    Oil & Gas industry hub

    State air regulations

    Forms

    Guidance

    Compliance

    State compliance obligations (reporting, emissions inventory, testing) are being indexed. Use the Compliance dashboard preview to see how they will be tracked.

    Sources

    Editorial note: Source conflict: Ecology's pages list Klickitat County (not San Juan) under Ecology jurisdiction; EPA's page lists San Juan (not Klickitat). Confirm with Ecology. Ecology's AOP page uses 'more than' thresholds. EPA Region 10 permits in Indian Country and the OCS.

    AirPermitHub provides educational, engineering, research, and compliance-support information. Information provided by the platform does not constitute legal advice and should not replace review of applicable regulations, permits, agency guidance, or consultation with qualified professionals. Full disclaimer