Air Plan Approval; SC; Updates to the Cross-State Air Pollution Rule

The Environmental Protection Agency (EPA) is proposing to approve a State Implementation Plan (SIP) revision submitted through the South Carolina Department of Health and Environmental Control (SC DHEC) on September 26, 2023, regarding updates to the State's Cross- State Air Pollution Rule (CSAPR) emissions trading programs. The SIP revision incorporates by reference (IBRs) certain amendments EPA has made to the regulations for the Federal CSAPR trading programs for annual emissions of nitrogen oxides (NO<INF>X</INF>) and sulfur dioxide (SO<INF>2</INF>) for large electric generating units (EGUs). EPA created these Federal trading programs in 2011 as market-based mechanisms for South Carolina and certain other States to address their obligations to downwind States under the Clean Air Act (CAA or Act)'s good neighbor provision with respect to the national ambient air quality standards (NAAQS) for fine particulate matter (PM<INF>2.5</INF>). EPA is proposing to approve South Carolina's September 26, 2023, SIP revision because it is consistent with EPA's good neighbor CSAPR trading programs and the CAA.