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Air Quality

Clean Air Interstate Rule (CAIR)

On August 21, 2012, the U.S Court of Appeals for the DC Circuit issued a ruling vacating the U.S. Environmental Protection Agency's (EPA) Cross State Air Pollution Rule (CSAPR). On June 24, 2013, the U.S. Supreme Court granted the EPA's petition asking the court to review the DC Circuit court's decision. For updates on this case, see EPA's CSAPR webpage.

CAIR is a program designed to reduce the amount of fine particulate matter and ozone that crosses state lines in the eastern United States. CAIR caps emissions of nitrogen oxides and sulfur dioxide and sets up a market for facilities to trade emissions credits.

On July 11, 2008, the U.S. Court of Appeals for the D.C. Circuit (Court of Appeals) vacated CAIR. Following petitions filed by parties in the litigation the Court of Appeals issued a subsequent opinion on December 23, 2008, wherein it remanded the CAIR to the U.S. Environmental Protection Agency (EPA) without vacatur.

CAIR is now in effect while EPA develops a replacement rule. South Carolina's CAIR regulations, at S.C. Regulation 61-62.96, went into effect on May 1, 2009, replacing the NOX SIP Call Program. DHEC implemented CAIR in South Carolina through a State Implementation Plan (SIP).


For more information please contact the Bureau of Air Quality at (803) 898-4123 or by email.