An official website of the United States government.

We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Clean Air Markets

Final Cross-State Air Pollution Rule Update

On this page:

Rule Summary

On September 7, 2016, the EPA finalized an update to the Cross-State Air Pollution Rule (CSAPR) for the 2008 ozone National Ambient Air Quality Standards (NAAQS) by issuing the final CSAPR Update.  Starting in May 2017, this rule will reduce summertime (May - September) nitrogen oxides (NOX) emissions from power plants in 22 states in the eastern U.S., providing up to $880 million in benefits and reducing ground-level ozone exposure for millions of Americans.  The rule will reduce air quality impacts of ozone pollution that crosses state lines and will help downwind areas meet and maintain the 2008 ozone air quality standard.

Top of Page

Rule History

September 13, 2019 - CSAPR Update Remanded

The US Court of Appeals for the DC Circuit remanded the CSAPR Update to the EPA to address the court’s holding that the rule unlawfully allows significant contribution to continue beyond downwind attainment deadlines.

September 7, 2016 - Final Cross-State Air Pollution Rule Update

The EPA finalized Federal Implementation Plans (FIPs) in the CSAPR Update to address air quality impacts of the interstate transport of ozone air pollution in the eastern United States.

Technical Support Documents (TSDs)

Petitions for Reconsideration

Previous Actions:

Top of Page

Additional Resources

Top of Page