Air Plan Approval; SC and TN; Regional Haze Plans and Prong 4 (Visibility) for the 2012 PM2.5

The Environmental Protection Agency (EPA) is approving the portions of South Carolina's and Tennessee's State Implementation Plan (SIP) revisions submitted by these States with letters dated September 5, 2017, and November 22, 2017, respectively, seeking to change reliance from the Clean Air Interstate Rule (CAIR) to the Cross-State Air Pollution Rule (CSAPR) for certain regional haze requirements; converting EPA's limited approvals/limited disapprovals of South Carolina's and Tennessee's regional haze plans to full approvals; removing EPA's Federal Implementation Plans (FIPs) for South Carolina and Tennessee that replaced reliance on CAIR with reliance on CSAPR to address the deficiencies identified in the limited disapprovals of South Carolina's and Tennessee's regional haze plans; and converting the conditional approvals to full approvals for the visibility prongs of South Carolina's infrastructure SIP submittals for the 2012 Fine Particulate Matter (PM2.5), 2010 Nitrogen Dioxide (NO2), 2010 Sulfur Dioxide (SO2), and 2008 8-hour Ozone National Ambient Air Quality Standards (NAAQS) and the visibility prongs of Tennessee's infrastructure SIP submittals for the 2012 PM2.5, 2010 NO2, and 2010 SO2 NAAQS.