Illinois; Disapproval of State Board Infrastructure SIP Requirements for the 2006 PM2.

The Environmental Protection Agency (EPA) is proposing to disapprove an element of State Implementation Plan (SIP) submissions from Illinois regarding the infrastructure requirements of section 110 of the Clean Air Act (CAA) for the 2006 fine particulate matter (PM 2.5 ) and 2008 ozone 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. This action pertains specifically to infrastructure requirements concerning state board requirements.