The Environmental Protection Agency (EPA) is approving, under the Clean Air Act (CAA), new and updated administrative rules for the Ohio State Implementation Plan (SIP) for the New Source Review (NSR) permitting program. The new and amended administrative rules in the Ohio Administrative Code (OAC) replace the currently effective procedural rules in the NSR SIP in their entirety. As part of this action, EPA is also approving the removal of obsolete language related to Significant Deterioration of Air Quality. EPA proposed to approve this action on February 26, 2021 and received no adverse comments.