Air Quality Designations for the 2008 Ozone National Ambient Air Quality Standards for Several Counties in Illinois, Indiana, and Wisconsin; Corrections to Inadvertent Errors in Prior Designations

This rule completes the initial air quality designations for the 2008 primary and secondary national ambient air quality standards (NAAQS) for ozone. On April 30, 2012, the EPA promulgated the initial ozone air quality designations for all areas in the United States except for 12 counties in Illinois, Indiana and Wisconsin, which the EPA was still evaluating. This action designates those counties. The EPA is designating all or parts of 11 counties as the Chicago- Naperville, IL-IN-WI nonattainment area. The EPA is designating the remaining county and parts of counties as unclassifiable/attainment. The Chicago-Naperville, IL-IN-WI nonattainment area is being classified by operation of law as a Marginal area according to the severity of its air quality problem. This rule also corrects inadvertent errors in the regulatory text regarding the designation of three areas in the ozone designation rule signed on April 30, 2012.