The Environmental Protection Agency (EPA) is finalizing approval of a State Implementation Plan (SIP) revision submitted by the State of South Carolina, through the South Carolina Department of Health and Environmental Control (hereinafter referred to as SC DHEC or South Carolina) via a letter dated February 3, 2022. The SIP revision updates portions of South Carolina's Prevention of Significant Deterioration (PSD) and Nonattainment New Source Review (NNSR) regulations, including changes to reflect the regulation of greenhouse gases (GHGs) pursuant to the Tailoring Rule and updates promulgated in the recent NSR Corrections Rule. With the exception of the Project Emissions Accounting provisions, which EPA expects to act on in a separate final rule, EPA is approving these revisions pursuant to the Clean Air Act (CAA or Act) and implementing Federal regulations.