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
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.