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Summary of Vancouver-Portland Ozone Maintenance Plan (Vancouver Portion)


The Portland/Vancouver air quality maintenance area (AQMA) was designated an interstate ozone nonattainment area and was further classified as marginal upon enactment of the Clean Air Act Amendments in 1990.

Washington State submitted an ozone maintenance plan for the Vancouver portion of the AQMA on June 13, 1996 and Oregon submitted an ozone maintenance plan for the Portland portion of the AQMA on August 30, 1996. The EPA approved the plans on May 19, 1997 (62 FR 27204 (PDF)(6 pp, 141 K, About PDF)).

On April 30, 2004 (69 FR 23858 (PDF)(95 pp, 537 K)), the EPA designated areas for the 1997 8-hour ozone standard and the Vancouver portion of the AQMA was designated attainment/unclassifiable. Subsequently, on June 15, 2005, the EPA revoked the 1-hour ozone standard.

The EPA had set forth requirements for antibacksliding purposes for areas that were designated attainment/unclassifiable for the 1997 8-hour ozone standard if the area had also been previously designated nonattainment for the 1-hour ozone standard.  Areas like the Vancouver Portion of the AQMA were required to submit a maintenance plan, under section 110(a)(1) of the Clean Air Act, to demonstrate that the area would continue to attain the 1997 8-hour ozone standard for at least 10 years.  The 110(a)(1) maintenance plan requirement did not include conformity obligations (unlike maintenance plans required under section 175A of the CAA).

On January 8, 2007, Washington State submitted to the EPA a section 110(a)(1) maintenance plan to maintain the 1997 8-hour ozone standard in the Vancouver portion of the AQMA through 2015. The EPA proposed to approve the maintenance plan on May 5, 2010 (75 FR 24542 (PDF)(3 pp, 145 K)) and took final action on August 11, 2015 (80 FR 48033 (PDF)(4 pp, 242 K)).


The plans rely on control strategies needed to assure maintenance of the National Ambient Air Quality Standards (NAAQS) for ozone. The strategy focuses on emission reductions from on-road vehicles, non-road vehicles, paints and household products, and industry.


  • WAC 173-422-030, Vehicle Emission Inspection Requirement
  • WAC 173-422-050, Emission Contributing Areas
  • WAC 173-422-060, Gasoline Vehicle Emission Standards
  • WAC 173-422-070, Gasoline Vehicle Exhaust Emission Testing Procedures
  • WAC 173-422-170, Exemptions
  • WAC 173-422-190, Emission Specialist Authorization
  • SWCAA 400-030, Definitions
  • SWCAA 400-101, Sources Exempt from Registration Requirements
  • SWCAA 400-109, Notice of Construction Application
  • SWCAA 400-110, New Source Review
  • SWCAA 400-112, Requirements for New Sources in Nonattainment Areas
  • SWCAA 400-113, Requirements for New Sources in Attainment or Nonclassifiable Areas 
  • SWCAA 400-114, Requirements for Replacement or Substantial Alteration for Emission Control Technology at an Existing Stationary Source
  • SWCAA 400-116, Maintenance of Equipment
  • SWCAA 400-190, Requirements for Nonattainment Areas
  • SWCAA 490-010 to 208, Emission Standards and Controls for Sources Emitting Volatile Organic Compounds
  • SWCAA 491-010 to 060, Emission Standards and Controls for Sources Emitting Gasoline Vapors
  • SWCAA 493-100, Consumer Products
  • SWCAA 493-200, Spray Paints
  • SWCAA 493-300, Architectural Coatings
  • SWCAA 493-400, Motor Vehicle Refinishing
  • SWCAA 493-500, Area Source Common Provisions

*For more information on the EPA-approved Washington rules (WAC), see Table 2 – Additional Regulations Approved for Washington Department of Ecology (Ecology) Direct Jurisdiction. For more information on the EPA-approved SWCAA rules, see Table 8 – Additional Regulations Approved for the Southwest Clean Air Agency (SWCAA) Jurisdiction.

Contingency Measures

  • SWCAA 400-111, Requirements for Sources in a Maintenance Plan Area

EPA Effective Date

June 18, 1997