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Summary of Northern Ada County (Boise) Carbon Monoxide Limited Maintenance Plan


Northern Ada County (Boise), Idaho, was designated nonattainment for carbon monoxide (CO) and classified as “not classified” upon enactment of the Clean Air Act Amendments in 1990.

Idaho submitted a CO maintenance plan on January 17, 2002 and EPA approved the plan on October 28, 2002 (67 FR 65713 (PDF)(6 pp, 148 K, About PDF)).


The plan relies on control strategies needed to maintain attainment of the National Ambient Air Quality Standards (NAAQS) for CO. The strategy focuses on motor vehicle control program, vehicle inspection and maintenance program, wood burning and outdoor burning.


  • 40 CFR Part 86 - Federal Motor Vehicle Emission Control Program
  • Automotive Inspection and Maintenance Program, 1991 Motor Vehicle Control Ordinances 
  • Ada County, 1999 Motor Vehicle Emissions Control Ordinance (June 15, 1999)
  • City of Boise, 1999 Motor Vehicle Emissions Control Ordinance (July 20, 1999)
  • City of Eagle, 1999 Motor Vehicle Emissions Control Ordinance (April 27, 1999)
  • Garden City, 1991 Motor Vehicle Emissions Control Ordinance (August 13, 1996)
  • City of Meridian, 1999 Motor Vehicle Emissions Control Ordinance (June 1, 1999)
  • Boise City Woodburning Ordinance and Boise City Burning Ban Enforcement Procedures, January 1, 1990
  • Wood Smoke Control Ordinances for the Cities of Garden City, Meridian, and Eagle, and for unincorporated Ada County

Contingency Measures

  • Institute an oxygenated fuels program or equivalent transportation control measure.

EPA Effective Date

December 27, 2002