Cross State Air Pollution Rule

The federal Cross State Air Pollution Rules (CSAPR) that West Virginia is subject are:

  • CSAPR Rule for fine particulate matter and ozone (SO2 and NOX) related to the 1997 Particulate Matter and Ozone National Ambient Air Quality Standards (NAAQS);
  • CSAPR Update Rule for ozone season NOX related to the 2008 Ozone Season NAAQS; and,
  • Revised CSAPR Update Rule for ozone season NOX related to the 2008 Ozone Season NAAQS (effective June 29, 2021).

The CSAPR is a federal implementation plan to reduce the interstate transport of air pollutants across state boundaries. The federal CSAPR programs replace the Clean Air Interstate Rule programs (CAIR). A December 2008 court decision kept the requirements of CAIR in place temporarily, but directed U.S. EPA to issue a new rule to implement the Clean Air Act requirements concerning interstate transport of air pollution. The CSAPR is designed to implement these Clean Air Act requirements and respond to the court's concerns. The CSAPR Rule took effect January 1, 2015 and replaced CAIR.

On September 7, 2016, the U.S. EPA revised the CSAPR ozone season NOX emission program (CSAPR Update Rule) for the 2008 Ozone NAAQS starting in May 2017.  On March 15, 2021, U.S. EPA finalized the Revised CSAPR Update for the 2008 ozone NAAQS.  Starting in the 2021 ozone season, the rule will require additional emissions reductions of NOX from power plants.

West Virginia DAQ finalized 45CSR43 effective May 1, 2019, to adopt the federal CSAPR and CSAPR Update limiting the interstate transport of emissions of PM2.5, NOX, ozone and SO2 through emissions trading programs.

For more information on CSAPR, click here.

Contact Information

Laura Crowder, Director of the Division of Air Quality
West Virginia Department of Environmental Protection
Division of Air Quality
601 57th St. SE
Charleston, WV 25304
Phone: (304) 926-0499 x41253
Email: laura.m.crowder@wv.gov