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.

Ground-level Ozone Pollution

2008 Ozone National Ambient Air Quality Standards (NAAQS) Nonattainment Actions

Proposed Determinations of Attainment by the Attainment Date, Extensions of the Attainment Date, and Reclassification of Several Areas Classified as Moderate for the 2008 Ozone National Ambient Air Quality Standards

November 7, 2018 - As required by the Clean Air Act, EPA has proposed actions for 11 nonattainment areas classified as Moderate for the 2008 ozone National Ambient Air Quality Standards. These areas were required to attain the standards by July 20, 2018. 

Final Actions on State Implementation Plan Components for the 2008 Ozone Air Quality Standards

November 29, 2017 - This final action finds that three states failed to submit timely state implementation plan (SIP) revisions necessary to satisfy certain Clean Air Act (CAA) and EPA requirements for implementing the 2008 ozone NAAQS. Specifically, this action applies to nonattainment areas reclassified in 2016 to Moderate nonattainment after failing to attain the NAAQS by the Marginal area attainment date of July 20, 2015.

February 3, 2017 - This final action finds that 15 states and the District of Columbia have failed to submit specific state implementation plan (SIP) elements to satisfy certain nonattainment area, and/or Ozone Transport Region (OTR), planning requirements for the 2008 ozone National Ambient Air Quality Standards (NAAQS).

Final Actions on Marginal Nonattainment Areas for the 2008 Ozone Standards
May 4, 2016 –  EPA made final determinations for whether the 36 nonattainment areas originally classified as Marginal for the 2008 ozone standards met the standards by the Clean Air Act established attainment date of July 20, 2015.

Proposed Actions on Marginal Nonattainment Areas for the 2008 Ozone Standards
August 27, 2015 – EPA is proposing to take one of three actions for the 36 areas designated as nonattainment and classified as marginal for the 2008 ozone standards and is requesting comment on two options for establishing the submittal deadline for State Implementation Plans (SIP) revisions due for the reclassified areas.

Implementing the 2008 8-hour Ozone National Ambient Air Quality Standards
March 6, 2015 – EPA finalized the SIP Requirements Rule, which establishes the requirements that state, tribal, and local air quality management agencies will need to meet as they develop implementation plans for areas where air quality exceeds the 2008 National Ambient Air Quality Standards (NAAQS) for ground-level ozone.

Proposed Withdrawal of the Determination that Compliance with Regional Emissions Trading Programs meets Clean Air Act Requirements to Control Emissions for the 1997 Ozone and Fine Particle Air Quality Standards
June 9, 2014 - EPA proposed a rule that would revise how emission controls for power plants should be treated in state plans to attain the 1997 ozone and fine particle air quality standards.

Final Approach for Establishing Nonattainment Area Classifications and Attainment Deadlines
May 21, 2012 - Final rule directs key aspects of the implementation of the 2008 National Ambient Air Quality Standards (NAAQS) for ground-level ozone. The portions of this final rule involving attainment deadlines and revoking the 1997 NAAQS for purposes of transportation conformity were vacated by the D.C. Circuit Court in NRDC v. EPA (12/23/2014).