Approval and Promulgation of Air Quality Implementation Plans; Kentucky; Approval of Section 110(a)(1) Maintenance Plans for the 1997 8-Hour Ozone Standards for the Edmonson County, KY; Greenup County Portion of the Huntington-Ashland, WV-KY; Lexington-Fayette, KY; and Owensboro, KY

EPA is taking final action to approve revisions to the Kentucky State Implementation Plan (SIP) that include maintenance plans addressing the 1997 8-hour ozone national ambient air quality standards (NAAQS or standards) for the following four Kentucky attainment areas: Edmonson County (hereafter referred to as the "Edmonson County Area"); the portion of Greenup County that was previously a part of the Huntington-Ashland, West Virginia-Kentucky 1-hour ozone maintenance area (hereafter referred to as the "Greenup County Area"); Fayette and Scott Counties (hereafter referred to as the "Lexington Area"); and Hancock County and the portion of Daviess County that was previously a part of the Owensboro 1-hour ozone maintenance area (hereafter referred to as the "Owensboro Area")--collectively, these areas will be referred to as the "Four Kentucky Areas." The Four Kentucky Areas were 1-hour ozone maintenance areas that were designated as attainment areas for the 1997 8-hour ozone NAAQS. As attainment areas that were previously 1-hour maintenance areas, Kentucky was required to submit maintenance plans demonstrating how these areas would maintain the 1997 8-hour ozone NAAQS. These maintenance plans were submitted to EPA on May 27, 2008, as revisions to the Kentucky SIP, by the Commonwealth of Kentucky (Commonwealth), through the Kentucky Energy and Environment Cabinet, Division for Air Quality (DAQ), and ensure the continued attainment of the 1997 8-hour ozone NAAQS through the year 2020 for the Four Kentucky Areas. These maintenance plans meet applicable statutory and regulatory requirements and are consistent with EPA's guidance. EPA is approving the revisions pursuant to the Clean Air Act (CAA or Act). This final rule also responds to adverse comments made on EPA's previously published proposed approvals of the maintenance plans for the Four Kentucky Areas.