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Vancouver 2nd 10-Year Carbon Monoxide Maintenance Plan Summary


The Vancouver, Washington, portion of the Portland-Vancouver Air Quality Maintenance Area was designated as nonattainment for carbon monoxide (CO) and classified as moderate upon enactment of the Clean Air Act Amendments in 1990.

 Vancouver has not violated the CO National Ambient Air Quality Standards (NAAQS) since 1990, and was formally redesignated to attainment on October 21, 1996 (61 FR 54560 (PDF)(4 pp, 126 K, About PDF)) when EPA approved Washington’s plan demonstrating that the area would continue to maintain the CO standard for ten years beyond redesignation.

On April 25, 2007, the State of Washington submitted a plan for maintaining the CO NAAQS for 10 years after the expiration of the first 10-year maintenance period. EPA approved the CO second 10-year maintenance plan on June 27, 2008 (73 FR 36439 (PDF)(5 pp, 158 K)).


The State of Washington developed a Limited Maintenance Plan to fulfill the Vancouver Area second 10-year maintenance period for CO. The plan retains the Washington State Vehicle Inspection and Maintenance program as a control strategy.


  • 40 CFR Part 86, Federal Motor Vehicle Emission Control Program 
  • WAC 173-422, Motor Vehicle Emission Inspection

Contingency Measures

  • WAC 173-492, Motor Fuel Specifications for Oxygenated Gasoline
  • SWCAA 492-010 to 100, Oxygenated Fuels
  • WAC 173-422, Motor Vehicle Emission Inspection (early implementation credit)
  • WAC 173-433, Solid Fuel Burning Device Standards
  • SWCAA 400-111, Requirements for Sources in a Maintenance Plan Area

EPA Effective Date

August 26, 2008