Approval and Promulgation of Implementation Plans and Designation of Areas for Air Quality Planning Purposes; Illinois; Ozone

EPA is approving a request from the State of Illinois to redesignate the Illinois portion of the Chicago-Gary-Lake County, Illinois-Indiana (IL-IN) area (the Greater Chicago area) to attainment of the 1997 8-hour ozone National Ambient Air Quality Standard (NAAQS or standard). The Illinois portion of the Greater Chicago area includes Cook, DuPage, Kane, Lake, McHenry, and Will Counties and portions of Grundy (Aux Sable and Goose Lake Townships) and Kendall (Oswego Township) Counties. The Illinois Environmental Protection Agency (IEPA) submitted this request on July 23, 2009, and supplemented its request on September 16, 2011. In addition to approval of Illinois' ozone redesignation request, EPA is: (1) Approving the State's plan for maintaining the 1997 8-hour ozone standard through 2025 and the State's 2002 Volatile Organic Compound (VOC) and Nitrogen Oxides (NOx) emission inventories, as revisions to the Illinois State Implementation Plan (SIP) for the Illinois portion of the Greater Chicago area; and (2) approving and finding adequate the State's 2008 and 2025 VOC and NOx Motor Vehicle Emission Budgets (MVEBs).