2015 Ozone Rule Timeline (Update)

On April 30, 2018, the EPA took the next step in the Clean Air Act (CAA) process to implement the 2015 Ozone National Ambient Air Quality Standard (NAAQS) by designating nearly all the remaining areas.  Eight counties in the San Antonio, Texas area will be designated by July 17, 2018.

The EPA touted a reduction in the number of areas of the country designated as nonattainment with the 2015 standard, relying on CAA waivers for emissions associated with natural “background” ozone and “exceptional events” such as wildfires to explain the reduction.

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 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 approval process which can also take years to complete. Finally, under the 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.

The EPA said that it followed state recommendations when identifying 51 nonattainment areas in 22 states and the District of Columbia, but noted that the agency acknowledges that high levels of background ozone are often “outside the control of state and tribal air agencies.” The EPA said there are more than 10 percent fewer counties being designated as nonattainment compared to the designations issued in 2012 for the 2008 ozone standard.

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 400 counties remain outstanding.


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

April 30, 2018 – EPA publishes additional designations for the 2015 Ozone standard


Contributed by Isaac Smith, Environmental Compliance Manager