Approval and Promulgation of Air Quality Implementation Plans; Indiana; Indiana PM2.5 NSR

Résumé

EPA is proposing to approve revisions to Indiana's state implementation plan as requested by the Indiana Department of Environmental Management (IDEM) to EPA on July 12, 2012, and December 12, 2012. The revisions to Indiana's state implementation plan (SIP) implement certain EPA regulations for particulate matter smaller than 2.5 micrometers (PM 2.5 ) by establishing definitions related to PM 2.5 , defining PM 2.5 increment levels, and setting PM 2.5 class 1 variances. The revisions also incorporate definitions and regulations that recognize nitrogen oxides (NO X ) as an ozone precursor.