Approval and Promulgation of Implementation Plans; Mississippi; 110(a)(1) and (2) Infrastructure Requirements for the 1997 8-Hour Ozone National Ambient Air Quality Standards

EPA is taking final action to approve the December 7, 2007, submission by the State of Mississippi, through the Mississippi Department of Environmental Quality (MDEQ) as demonstrating that the State meets the implementation plan (SIP) requirements of sections 110(a)(1) and (2) of the Clean Air Act (CAA or the Act) for the 1997 8- hour ozone national ambient air quality standards (NAAQS). Section 110(a) of the CAA requires that each state adopt and submit a SIP for the implementation, maintenance, and enforcement of each NAAQS promulgated by the EPA, which is commonly referred to as an "infrastructure" SIP. Mississippi certified that the Mississippi SIP contains provisions that ensure the 1997 8-hour ozone NAAQS is implemented, enforced, and maintained in Mississippi (hereafter referred to as "infrastructure submission"). Mississippi's infrastructure submission, provided to EPA on December 7, 2007, addressed all the required infrastructure elements for the 1997 8-hour ozone NAAQS. Additionally, EPA is responding to adverse comments received on EPA's March 17, 2011, proposed approval of Mississippi's December 7, 2007, infrastructure submission.