Approval and Promulgation of Implementation Plans Reinstatement of Redesignation of Area for Air Quality Planning Purposes; Kentucky Portion of the Cincinnati-Hamilton Area

The Cincinnati-Hamilton moderate 1-hour ozone nonattainment area (Cincinnati-Hamilton area) includes the Ohio Counties of Hamilton, Butler, Clermont, and Warren and the Kentucky Counties of Boone, Campbell, and Kenton. In a Federal Register notice published June 19, 2000, the Cincinnati-Hamilton area was redesignated to attainment for the 1-hour ozone National Ambient Air Quality Standard (NAAQS) effective July 5, 2000. On September 11, 2001, the United States Court of Appeals for the 6th Circuit vacated EPA's redesignation of the Cincinnati-Hamilton area, after concluding that EPA erred in one respect that pertained solely to the Ohio portion of the area. Wall v. EPA, 265 F.3d 426 (6th Cir. 2001). Therefore, in response to the Court's findings, this rulemaking action reinstates EPA's redesignation to attainment for the 1-hour ozone NAAQS for the Kentucky portion of the Cincinnati-Hamilton area, to become effective as of the effective date of the original redesignation action. EPA is addressing the remand relating to the Ohio portion of the Cincinnati-Hamilton area in a separate rulemaking action.