The United States Environmental Protection Agency (EPA) approves Ohio's State Implementation Plan (SIP) revisions for New Source Review (NSR) in nonattainment areas. Previously, EPA issued both a direct final approval and a proposed approval of Ohio's revisions. EPA withdrew the direct final action upon receiving adverse comments. In this action, EPA responds to the public comments received and announces EPA's final rulemaking action. In consideration of the comments and the requirements of the Clean Air Act (CAA), EPA now fully approves Ohio's nonattainment NSR program as an addition to the SIP. Recently, EPA announced new regulations regarding changes to the NSR Program through efforts under "NSR Reform." Today's approval of Ohio's NSR SIP submission does not address EPA's new rules but is limited to portions of Ohio's program under prior existing rules. EPA is taking no position today on whether Ohio will need to make changes to its SIP to meet any new requirements that EPA may promulgate as part of "NSR Reform."