EPA Makes Final Attainment Designations for 2015 Ozone NAAQS

January 8, 2018

On December 21, 2017, EPA responded to state and tribal recommendations by indicating the anticipated area designations for the portions of the country not already designated for the 2015 ozone standards.  These responses will start a 120-day period for states and tribes to provide additional information before EPA determines the final designations.  EPA will also be opening a 30-day comment period for the public to provide input on these designations before they are finalized.

On November 6, 2017, EPA designated 2,646 counties as Attainment/Unclassifiable for which the states recommended a designation of Attainment or Attainment/ Unclassifiable. These are counties with one or more monitors attaining the 2015 ozone NAAQS, or counties for which the EPA does not have reason to believe are violating the 2015 ozone NAAQS or are contributing to a violation of the 2015 ozone NAAQS in another county.  Designations for more than counties remain outstanding.

Although the 70 ppb ozone standard was finalized in 2015, the EPA has yet to finalize how implementation of the rule will be handled.  The EPA has stated that some of the guidance and rules from the 2008 standard remain applicable; however, there continue to be questions on nonattainment classification thresholds and how to address background ozone concentrations.

Counties and areas classified as nonattainment can face significant challenges in the form of air permitting delays, restrictions on industry expansion within the area, as well as impacts to transportation planning.  These challenges commonly lead to reduced economic development in and around the nonattainment area in addition to greater EPA involvement and oversight in air permit permitting.

After nonattainment areas are designated, states will have up to 3 years to produce State Implementation Plans (SIPs), which outline measures to reduce emission levels to attain and/or maintain the NAAQS. SIPs must be codified through an EPA review and go through an approval process which can also take years to complete. Finally, under the Clean Air Act (CAA), actual attainment of the standards is allowed to stretch over a 3-year to 20-year period, depending on the severity of the area’s pollution.

Rule History

  • December 17, 2014 – Ozone NAAQS Proposed Rule published in Federal Register (FR)
  • October 26, 2015 – Ozone NAAQS Final Rule published in FR
  • June 28, 2017 – Scott Pruitt announces 1 year extension (Oct 1, 2018) on initial area designations
  • August 2, 2017 – Scott Pruitt withdraws notice delaying initial area designations
  • October 1, 2017 – Statutory requirement date for initial area designations by EPA
  • November 6, 2017 – EPA designates most of the U.S. “attainable/unclassifiable”
  • December 21, 2017 – EPA responds to state and Tribal Recommendations
Contributed by Isaac Smith, Environmental Compliance Manager