Approval and Promulgation of Air Quality Implementation Plans; Indiana; Clean Air Interstate Rule

EPA is proposing to approve a request submitted by the Indiana Department of Environmental Management (IDEM) on June 29, 2009, to revise the Indiana State Implementation Plan (SIP) under the Clean Air Act (CAA). The State has submitted amendments to the Indiana Administrative Code (IAC), which supplement Indiana's Clean Air Interstate Rule (CAIR), for which EPA granted limited approval as an abbreviated SIP on October 22, 2007. The State's June 29, 2009, submittal includes elements that EPA deems necessary in order for EPA to fully approve Indiana's CAIR SIP. This will allow a transition from an abbreviated SIP with limited approval to a full SIP with full approval under which the various CAIR implementation provisions would be governed by State rules rather than Federal Implementation Plan (FIP) rules. This action results in the withdrawal of the Indiana CAIR FIP concerning sulfur dioxide (SO<INF>2</INF>), nitrogen oxides (NO<INF>X</INF>) annual, and NO<INF>X</INF> ozone season emissions.