The Environmental Protection Agency (EPA) is approving a portion of a State Implementation Plan (SIP) revision to the Mecklenburg County portion of the North Carolina SIP, hereinafter referred to as the Mecklenburg County Local Implementation Plan (LIP). The revision was submitted through the North Carolina Division of Air Quality (NCDAQ), on behalf of Mecklenburg County Air Quality (MCAQ), via a letter dated April 24, 2020, which was received by EPA on June 19, 2020. This SIP revision includes changes to Mecklenburg County Air Pollution Control Ordinance (MCAPCO) rules incorporated into the LIP regarding Prevention of Significant Deterioration (PSD) permitting to address changes to the Federal new source review (NSR) regulations in recent years. EPA is approving these changes pursuant to the Clean Air Act (CAA or Act).