Air Plan Approval; Illinois; Base Year Emission Inventories for the 20088-Hour Ozone Standard

The Environmental Protection Agency (EPA) is approving a State Implementation Plan (SIP) revision submitted by the Illinois Environmental Protection Agency (IEPA) on September 3, 2014, to address emission inventory requirements for the Illinois portions of the Chicago-Naperville, Illinois-Indiana-Wisconsin (IL-IN-WI) and St. Louis, Missouri-Illinois (MO-IL) ozone nonattainment areas under the 2008 ozone National Ambient Air Quality Standard (NAAQS or standard). The Clean Air Act (CAA) requires emission inventories for all ozone nonattainment areas. The emission inventories contained in Illinois' September 3, 2014, submission meet this CAA requirement.