Approval and Promulgation of Air Quality Implementation Plans; Illinois

EPA is proposing to approve a July 29, 2010, request from the State of Illinois to exempt sources of Nitrogen Oxides (NO<INF>X</INF>) in the Illinois portions of the Chicago-Gary-Lake County, Illinois- Indiana and St. Louis, Missouri-Illinois 8-hour ozone nonattainment areas from Clean Air Act (CAA) requirements for NO<INF>X</INF> Reasonably Available Control Technology (RACT) for purposes of attaining the 1997 8-hour ozone National Ambient Air Quality Standard (NAAQS). The State's NO<INF>X</INF> RACT waiver request is based on the most recent three years of complete, quality-assured ozone monitoring data, which demonstrate that additional reduction of NO<INF>X</INF> emissions in the ozone nonattainment areas would not contribute to attainment of the 1997 8-hour ozone NAAQS in the two ozone nonattainment areas. In addition to waiving the NO<INF>X</INF> RACT requirement for the State of Illinois, final approval of the NO<INF>X</INF> RACT waiver would also suspend a requirement for EPA to promulgate a NO<INF>X</INF> RACT Federal Implementation Plan (FIP) for the 8-hour ozone nonattainment areas.