Approval and Promulgation of Air Quality Implementation Plan; Illinois; Redesignation of the Chicago Area to Attainment of the 1997 Annual Fine Particulate Matter Standard

EPA is taking several related actions under the Clean Air Act (CAA) affecting the Chicago area and the state of Illinois for the 1997 annual fine particulate matter (PM<INF>2.5</INF>) National Ambient Air Quality Standard (NAAQS or standard). EPA is determining that the Chicago-Gary-Lake County, Illinois-Indiana (IL-IN) area is attaining the 1997 annual PM<INF>2.5</INF> standard based on quality assured, state-certified monitoring data for all PM<INF>2.5</INF> monitoring sites in this area from 2007-2012. EPA is granting a request from the state of Illinois to redesignate the Chicago area to attainment of the 1997 annual PM<INF>2.5</INF> standard. EPA is approving, as a revision of the Illinois State Implementation Plan (SIP), the state's plan for maintaining the 1997 annual PM<INF>2.5</INF> standard in the Chicago- Gary-Lake County, IL-IN area through 2025. EPA is approving Illinois' comprehensive 2002 Nitrogen Oxides (NO<INF>X</INF>), Sulfur Dioxide (SO<INF>2</INF>), Volatile Organic Compound (VOC), ammonia, and primary PM<INF>2.5</INF> emission inventories for the Chicago area. Finally, EPA is approving Illinois' 2008 and 2025 NO<INF>X</INF> and primary PM<INF>2.5</INF> Motor Vehicle Emission Budgets (MVEBs) for the Chicago area and finding these MVEBs as adequate for use in transportation conformity determinations. The Chicago area includes: Cook, DuPage, Kane, Lake, McHenry, and Will Counties, Aux Sable and Goose Lake Townships in Grundy County, and Oswego Township in Kendall County. The Chicago-Gary-Lake County, IL-IN area also includes Lake and Porter Counties in Indiana, which have been previously redesignated to attainment of the 1997 annual PM<INF>2.5</INF> standard.