Approval and Promulgation of Air Quality Implementation Plans; Illinois; Infrastructure SIP Requirements for the 2008 Ozone, 2010 NO2, and 2010 SO2 NAAQS

The Environmental Protection Agency (EPA) is taking final action to approve some elements and disapprove other elements of a state implementation plan (SIP) submission from Illinois regarding the infrastructure requirements of section 110 of the Clean Air Act (CAA) for the 2008 ozone, 2010 nitrogen dioxide (NO<INF>2</INF>), and 2010 sulfur dioxide (SO<INF>2</INF>) National Ambient Air Quality Standards (NAAQS). The infrastructure requirements are designed to ensure that the structural components of each state's air quality management program are adequate to meet the state's responsibilities under the CAA. Illinois already administers Federally promulgated regulations that address the disapprovals described in this rulemaking. Therefore, the state will not be obligated to submit any new or additional regulations as a result of this final disapproval. The proposed rulemaking associated with this final action was published on July 14, 2014, and EPA received one comment letter during the comment period, which ended on August 13, 2014. The concerns raised in this letter, as well as EPA's responses, will be addressed in this final action.