Proposed rule · 2025-08728

Air Plan Approval; Ohio; Second Maintenance Plan for 2008 Ozone NAAQS

The Environmental Protection Agency (EPA) is proposing to approve revisions to the Ohio State Implementation Plan (SIP). On November 6, 2024, the Ohio Environmental Protection Agency (Ohio EPA) submitted the state's plans for maintaining the 2008 ozone National Ambient Air Quality Standard (NAAQS or standard) in the Columbus, Ohio; Cleveland-Akron-Lorain, Ohio; and Cincinnati, Ohio-Kentucky-Indiana areas. EPA is proposing to approve these maintenance plans because they provide for the maintenance of the 2008 ozone NAAQS for each area for 10 additional years as required by the Clean Air Act (CAA). EPA is also initiating the adequacy review process for motor vehicle emission budgets (Budgets) for each area. This action, if finalized, would make certain commitments related to maintenance of the 2008 ozone NAAQS in these areas federally enforceable as part of the Ohio SIP.