Air Plan Approval; Kentucky; 2008 Ozone NAAQS Interstate Transport SIP Requirements

The Environmental Protection Agency (EPA) is approving a revision to Kentucky's State Implementation Plan (SIP) pertaining to the "good neighbor" provision of the Clean Air Act (CAA or Act) for the 2008 8-hour ozone National Ambient Air Quality Standard (NAAQS). Kentucky submitted a draft version of this SIP revision for parallel processing by EPA on February 28, 2018, and submitted a final version that contained no substantive changes on May 10, 2018. The good neighbor provision requires each state's implementation plan to address the interstate transport of air pollution in amounts that contribute significantly to nonattainment, or interfere with maintenance, of a NAAQS in any other state. In this action, EPA is approving Kentucky's submission demonstrating that no additional emission reductions are necessary to address the good neighbor provision for the 2008 ozone NAAQS beyond those required by the Cross-State Air Pollution Rule Update (CSAPR Update) federal implementation plan (FIP). Accordingly, EPA is approving Kentucky's submission because it partially addresses the requirements of the good neighbor provision for the 2008 ozone NAAQS, and it resolves any obligation remaining under the good neighbor provision after promulgation of the CSAPR Update FIP. The approval of Kentucky's SIP submission and the CSAPR Update FIP, together, fully address the requirements of the good neighbor provision for the 2008 ozone NAAQS for Kentucky. EPA is approving this action because it is consistent with the CAA.