Approval of Air Quality Implementation Plans; Indiana and Ohio; Disapproval of Interstate Transport State Implementation Plan Revision for the 2006 24-hour PM2.5 NAAQS

Pursuant to its authority under the Clean Air Act (CAA), EPA is taking final action to disapprove the portions of submittals by the Indiana Department of Environmental Management (IDEM) and the Ohio Environmental Protection Agency (Ohio EPA) that pertain to requirements in the CAA to address interstate transport for the 2006 24-hour fine particle (PM<INF>2.5</INF>) National Ambient Air Quality Standards (NAAQS). EPA is not, however, currently taking action on the remainder of the State Implementation Plan (SIP) submittals from IDEM and Ohio EPA concerning other basic or "Infrastructure" elements required under the CAA. The proposed rule associated with this final action was published on February 4, 2011. The effect of this action will be an obligation for EPA to promulgate a Federal Implementation Plan (FIP) for Indiana and Ohio no later than two years from the date of disapproval. The Transport Rule, when final, is the FIP that EPA intends to implement for Indiana and Ohio.