The Environmental Protection Agency (EPA) is finalizing approval of a state implementation plan (SIP) revision submitted by the State of North Carolina, through the North Carolina Department of Environment Quality, Division of Air Quality (DAQ), via a letter dated December 9, 2021. The SIP revision includes the 1997 8-hour ozone National Ambient Air Quality Standards (NAAQS) Limited Maintenance Plan (LMP) for the North Carolina portion (hereinafter referred to as the Metrolina Area) of the Charlotte-Gastonia-Rock Hill NC-SC 1997 8-hour ozone maintenance area (hereinafter referred to as the "Charlotte NC- SC 1997 8-hour NAAQS Area" or "bi-state Charlotte Area"). The Charlotte NC-SC 1997 8-hour NAAQS Area is comprised of Cabarrus, Gaston, Lincoln, Mecklenburg, Rowan and Union Counties and a portion of Iredell County (i.e., Davidson and Coddle Creek Townships) in North Carolina; and the Rock Hill Metropolitan Planning Organization boundary in York County, South Carolina. EPA is finalizing approval because the LMP provides for the maintenance of the 1997 8-hour ozone NAAQS within the Metrolina Area through the end of the second 10-year portion of the maintenance period. This action makes certain commitments related to maintenance of the 1997 8-hour ozone NAAQS in the Metrolina Area federally enforceable as part of the North Carolina SIP.