Implementation of the 1997 and 2006 Particulate Matter (PM2.5) National Ambient Air Quality Standards (NAAQS)

On this page:

• Rule Summary
• Rule History
• Additional Resources

Rule Summary

On January 4, 2013, in Natural Resources Defense Council (NRDC) v. EPA, the D.C. Circuit Court remanded to the Environmental Protection Agency (EPA) the ‘‘Final Clean Air Fine Particle Implementation Rule’’ and the ‘‘Implementation of the New Source Review (NSR) Program for Particulate Matter Less than 2.5 Micrometers (PM_2.5)’’ final rule. The Court found that the EPA erred in implementing the 1997 PM 2.5 National Ambient Air Quality Standards (NAAQS) pursuant solely to the general implementation provisions of subpart 1 of Part D of Title I of the Clean Air Act (CAA or Act), without also considering the particulate matter-specific provisions of subpart 4 of Part D. The Court’s ruling remanded the rules to the EPA to address implementation of the 1997 PM_2.5 NAAQS under subpart 4.

Rule History

12/24/2024 - Final Rule; Correcting Amendment

10/08/2024 Correcting Amendments

10/03/2014 Correcting Amendments

6/02/2014 Final Rule

11/21/2013 Proposed Rule

01/04/2013 - DC Circuit Court Decision on Natural Resources Defense Council (NRDC) v. EPA

Additional Resources

Natural Resources Defense Council (NRDC) v. EPA Fact Sheet

Identification of Nonattainment Classification and Deadlines for Submission of State Implementation Plan (SIP) for the 1997 and 2006 Fine Particle National Ambient Air Quality Standards (NAAQS) Fact Sheet

Related Rules

Identification of Nonattainment Classification and Deadlines for Submission of State Implementation Plan (SIP) for the 1997 and 2006 Fine Particle National Ambient Air Quality Standards (NAAQS)

2006 National Ambient Air Quality Standards (NAAQS) for Particulate Matter (PM_2.5)

Determinations of Attainment, Failure to Attain and Reclassifications for the 2006 24-hour fine particle pollution standards