On November 25, 2014, EPA proposed revising the National Ambient Air Quality Standard (NAAQS) for ozone, recommending a standard between 65 to 70 parts per billion (ppb) for both the 8-hour primary and secondary standards. The current ozone standard is set at 75 ppb. The Clean Air Scientific Advisory Committee (CASAC) concluded that scientific evidence supported a standard between 60 to 70 ppb. Ultimately, EPA decided to propose a new standard between 65 and 70 ppb, but is taking comment on whether a 60 ppb standard should be established for the primary standard or whether the existing 75 ppb standard should be retained. EPA is also proposing to extend the length of the ozone monitoring season in 33 states. 

Currently, the northern Kentucky counties of Boone, Kenton, and Campbell are designated as partial nonattainment with the existing 75 ppb ozone standard. But other counties could ultimately be designated as nonattainment depending on which value EPA chooses for the final standard. 

In anticipation of the EPA’s proposal to revise the ozone NAAQS, Kentucky Governor Steve Beshear sent a letter to President Barack Obama on November 21, 2014 outlining the Governor’s concerns relating to the economic impact of the proposed standards and recommending that the standard remain unchanged. The letter indicates that if a 60 ppb standard is ultimately chosen all 29 of Kentucky’s air monitors would exceed the standard. 

Previously, in 2008, EPA revised the 8-hour primary ozone standard from 80 ppb to the current 75 ppb standard. EPA had allowed states to show compliance with the NAAQS more than three years after an area is designated “nonattainment” by extending the deadline to the end of the calendar year rather than three years from the designation date. However, the D.C. Circuit Court of Appeals recently held that this was contrary to the Clean Air Act’s mandated deadlines in National Resources Defense Council (NRDS) v. EPA, (Case No. 12-1321, Dec. 23, 2014). This ruling could potentially pose restrictions on how EPA plans to implement the new standard. 

The proposed rule includes grandfather provisions that would allow facilities with pending PSD applications, that have gone to public notice or have been determined complete before dates tied to the issuance of the final rule, to be reviewed based upon the current ozone standard. To meet the deadlines for the grandfather provisions in the proposed rule, facilities may need to submit PSD applications by as early as August, 2015.