U.S. EPA Adopts New Ozone NAAQS


On October 1, 2015, US EPA announced that it will lower the National Ambient Air Quality Standard (NAAQS) for ground-level ozone from 75 parts per billion (ppb) to 70 ppb. US EPA was considering lowering the standard to as low as 60 ppb.

Based on air quality data from 2012 through 2014, only eight counties in Ohio (Ashtabula, Cuyahoga, Geauga, Lake, Lorain, Medina, Portage, and Summit) do not meet the current ozone standard of 75 ppb. With the new standard in place, 17 Ohio counties (Allen, Ashtabula, Butler, Clark, Clermont, Clinton, Cuyahoga, Delaware, Franklin, Hamilton, Lake, Lucas, Madison, Miami, Montgomery, Trumbull, and Warren) will not meet the 70 ppb NAAQS for ozone. Furthermore, Ohio EPA estimates that, based on US EPA’s factor analysis for designating nonattainment areas, as many as 34 of Ohio’s 88 counties could be designated nonattainment.

US EPA will designate nonattainment areas in late 2017, likely based on air quality data from 2014-2016. Depending on the severity of the non-attainment designation, nonattainment areas will have between 2020 and 2037 to meet the standard. US EPA estimates that most areas will meet the standards by 2025. Ohio and all other states with non-attainment areas will be required to update their State Implementation Plans (SIP) to demonstrate attainment of the new standard by about 2025.

New facilities locating in an ozone non-attainment with potential emissions of either VOCs or NOx of greater than 100 tons/yr would be subject to Non-Attainment New Source Review (NNSR) permitting requirements. Physical changes or changes in the method of operation to sources located at existing facilities located in an ozone non-attainment area with potential emissions greater than 100 tons/yr of VOCs or NOx which are proposing an emission increase of greater than 40 tons/yr of VOC or NOx or a net emissions increase of greater than 40 tons/yr of VOC or NOx would be subject to NNSR permitting requirements. Projects subject to NNSR permitting requirements are required to meet Lowest Achievable Emission Rate (LAER) requirements, obtain VOC and/or NOx emissions offsets and demonstrate a net air quality improvement.

States may also have to expand existing regulatory requirements or impose new regulatory requirements in order to demonstrate attainment of the new ozone standard. These new or expanded regulatory requirements could affect both major and minor sources.

Contact Ron Hansen at (614) 794-3570 ext. 21 if you have any questions.