Approval and Promulgation of Air Quality Implementation Plans; Montana; Thompson Falls PM10 Nonattainment Area Control Plan

EPA is proposing to approve State Implementation Plan (SIP) revisions submitted by the Governor of Montana on June 26, 1997, and June 13, 2000. (Portions of the June 26, 1997, submittal were withdrawn by the Governor of Montana on February 8, 1999.) These revisions contain an inventory of emissions for Thompson Falls and establish and require continuation of all control measures adopted and implemented for reductions of particulate matter with an aerodynamic diameter less than or equal to 10 micrometers (PM<INF>10</INF>) in order to attain the PM<INF>10</INF> National Ambient Air Quality Standards (NAAQS) in Thompson Falls. Using the PM<INF>10</INF> clean data areas approach, we propose to approve the control measures and the emissions inventory that were submitted as part of the PM<INF>10</INF> nonattainment area SIP for Thompson Falls. Also, we will be taking action on other portions of the June 26, 1997, and June 13, 2000, submittals at a later time. We are acting under section 110 of the Clean Air Act (CAA or Act) for this proposed approval.