Approval and Promulgation of Air Quality Implementation Plans; State of Montana; Missoula Carbon Monoxide Redesignation to Attainment, Designation of Areas for Air Quality Planning Purposes, and Approval of Related Revisions

EPA is approving State Implementation Plan (SIP) revisions submitted by the State of Montana. EPA is approving a request submitted by the State of Montana on May 27, 2005 requesting to redesignate the Missoula "moderate" carbon monoxide (CO) nonattainment area to attainment for the CO National Ambient Air Quality Standard (NAAQS). EPA is also approving the CO maintenance plan, which was also submitted on May 27, 2005 and includes transportation conformity motor vehicle emission budgets (MVEB) for 2000, 2010, and 2020. Lastly, EPA is approving CO periodic emission inventories for 1993 and 1996 that the State had previously submitted for the Missoula nonattainment area. The intended effect of this action is to make federally enforceable those provisions that EPA is approving. This action is being taken under section 110 of the Clean Air Act (CAA).