Air Plan Approval; Indiana; Attainment Plan for Indianapolis and Terre Haute SO2 Nonattainment Areas

The Environmental Protection Agency (EPA) is taking final action to approve State Implementation Plan (SIP) revisions that Indiana submitted to EPA on October 2, 2015 for attaining the 2010 sulfur dioxide (SO<INF>2</INF>) national ambient air quality standard (NAAQS) for the Indianapolis (Marion County) and Terre Haute (Vigo County) areas. EPA proposed this action on August 15, 2018 and did not receive any relevant public comments. These revisions (herein called the "attainment plans" or "plans") include Indiana's attainment demonstration and other elements required under the Clean Air Act (CAA) for the two areas. In addition to an attainment demonstration, the plans address: The requirement for meeting reasonable further progress (RFP) toward attainment of the NAAQS, reasonably available control measures and reasonably available control technology (RACM/RACT), emission inventories, and contingency measures. EPA further concludes that Indiana has demonstrated that the plans provide for attainment of the 2010 SO<INF>2</INF> NAAQS in the Indianapolis and Terre Haute areas by the attainment date of October 4, 2018.