Approval and Promulgation of Air Quality Implementation Plans; Montana; Emergency Episode Plan, Columbia Falls, Butte and Missoula Particulate Matter State Implementation Plans, Missoula Carbon Monoxide State Implementation Plan

EPA is taking direct final action approving State Implementation Plan (SIP) revisions submitted by the State of Montana. The revisions update the State of Montana's Emergency Episode Plan; Columbia Falls, Butte and Missoula's Particulate Matter (particulate matter with an aerodynamic diameter less than or equal to a nominal 10 micrometers (PM-10)) Plans; and the Missoula carbon monoxide (CO) Plan. The intended effect of this action is to make the federally approved SIP consistent with the State adopted SIP with respect to the Emergency Episode Plan, Columbia Falls, Butte and Missoula's PM-10 SIPS and Missoula's CO SIP. EPA is taking this action under sections 110 and 179 of the Clean Air Act (Act). EPA is also updating out-of-date sections in 40 CFR part 52, subpart BB--Montana.