Approval and Promulgation of Implementation Plans and Designation of Areas for Air Quality Planning Purposes; Illinois; Redesignation of the Illinois Portion of the St. Louis, MO-IL Area to Attainment for the 1997 8-hour Ozone Standard

EPA is approving a request from the State of Illinois to redesignate the Illinois portion of the St. Louis, MO-IL area to attainment of the 1997 8-hour ozone National Ambient Air Quality Standard (NAAQS or standard). The St. Louis area includes Jersey, Madison, Monroe, and St. Clair Counties in Illinois and St. Louis City and Franklin, Jefferson, St. Charles, and St. Louis Counties in Missouri. The Illinois Environmental Protection Agency (IEPA) submitted this request on May 26, 2010, and supplemented its request on September 16, 2011. EPA proposed to approve this submission on December 22, 2011, and provided a 30-day review and comment period. On January 20, 2012, EPA extended the public comment period for an additional 30 days. The comment period closed on February 22, 2012. EPA received comments submitted on behalf of Sierra Club. In addition to approving the redesignation request EPA is taking several other related actions. EPA is approving, as a revision to the Illinois State Implementation Plan (SIP), the State's plan for maintaining the 1997 8-hour ozone standard through 2025 in the area. EPA is approving the 2002 emissions inventory, submitted by IEPA on June 21, 2006, and supplemented on September 16, 2011, as meeting the comprehensive emissions inventory requirement of the Clean Air Act (CAA) for the Illinois portion of the St. Louis area. Finally, EPA finds adequate and is approving the State's 2008 and 2025 Motor Vehicle Emission Budgets (MVEBs) for the Illinois portion of the St. Louis area.