New Primary and Secondary Ozone NAAQS Requirements

By Joshua Haar, EIT

The US EPA has revised the National Ambient Air Quality Standards (NAAQS) for ground level ozone. This will impact new and existing industrial facilities in some locations.


The NAAQS were implemented as part of the Clean Air Act in the 1970’s to protect public health from a variety of pollutants, including particulates, carbon monoxide, and ozone, among others. The ozone NAAQS were instituted to limit the health effects (e.g. reduced lung function and pulmonary inflammation) caused by ground level ozone in the atmosphere; effects that primarily impact children, older adults, and people with asthma or other lung diseases. While ozone in the stratosphere helps block harmful radiation from reaching the surface of the earth, ozone at ground level is harmful. Specifically, it is not easily removed by our upper respiratory tract and is absorbed in our lungs, where it can cause narrowing of airways and decrease lung function.

The New Standard

The EPA released a draft NAAQS in December 2014 for public comment and review that listed the revised primary and secondary ozone standards of between 0.065 ppm and 0.070 ppm. Based on public comment on the rules, the new ozone NAAQS primary and secondary ozone standard of 0.070 ppm became effective on October 26, 2015. While this is lower than the 2008 standard, it is not as low as many people thought the standard could have gone. While this shouldn’t significantly affect most areas, there will be some counties that become non-attainment areas under the new standard.

With the new standard of 0.070 ppm, federal, state, and local agencies will have to begin implementing measures to limit the amount of ozone and ozone creating pollutants that are emitted in their jurisdiction. This includes designating any new non-attainment areas that do not meet the standard. Once an area has been designated as a non-attainment area, the agency with jurisdiction must devise a strategy to address the issue.  Often this includes establishing lower thresholds for volatile organic compounds (VOC) and nitrous oxides (NOx) that trigger industrial facilities to be classified as major sources, thus being subject to more stringent federal air permitting standards. Additionally, new stationary sources in non-attainment areas are required to implement Lowest Achievable Emission Rate (LAER), which is the most stringent air pollution control standard.

In Georgia

Currently, the only non-attainment areas listed by the EPA are in the 15 county Atlanta metro-area. Despite being listed as non-attainment, most of these counties were under the 2008 standard (0.075 ppm) and are currently under the new standard of 0.070 ppm. The Clean Air Act requires the Georgia Environmental Protection Division (GA EPD), along with other state and local agencies, to submit non-attainment designations to the EPA).  The EPA is recommending that all 15 counties in the Atlanta metro area, including the addition of Barrow, Spalding and Walton counties, be included in the non-attainment area, since they believe that these counties directly impact the air quality in the Atlanta area and contribute to the non-attainment.

The new standard will likely make it more difficult for GA EPD to make the case that only Cobb, DeKalb, Fulton, and Henry be included as non-attainment areas, as requested in 2009 and 2011, as Gwinnett and Rockdale counties are now also in non-attainment. However, GA EPD will likely continue to make the case and that only the counties with ozone concentrations above the standard be included as non-attainment areas. Additionally, due to increases in fuel efficiency, increased pollution control on vehicles, and pollution control devices at industrial and municipal facilities, there has been a marked decrease in ozone concentrations over the last several years. It is possible that within the next 5-10 years, the Atlanta area could reach even the new ozone standard.

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