Environmental Groups Fight for Stronger Regulation of Ground-level Ozone Pollution

Daniel Bourgault

Journal of Regulatory Compliance Applicant

Loyola University of Chicago School of Law, JD 2022

On  February 11, 2021, a host of environmental groups filed a Petition for Review with the U.S. Court of Appeals for the D.C. Circuit challenging a final action of the Environmental Protection Agency (“EPA”) in regard to the review of National Ambient Air Quality Standards (“NAAQS”) for ground-level ozone. The final action taken by the EPA that is being challenged was to retain the current standards that were promulgated in 2015 without any revisions. The 2015 review by the EPA resulted in revisions of the ground-level ozone NAAQS from 0.075 parts per million (“ppm”) to 0.070 ppm in light of scientific evidence and quantitative exposure/risk information. The 2015 revision was challenged by industry representatives as too stringent, as well as by environmental groups as not stringent enough despite the tightening of the standard, but the challenges were ultimately dismissed in court. Now, in light of the decision of the EPA to retain those 2015 standards, environmental groups are once again asserting that the primary standard for ground-level ozone of 0.070 ppm is not sufficient to protect public health and welfare as required by the Clean Air Act.

NAAQS and the regulation of ozone under the CAA

The Clean Air Act (“CAA”) charges the EPA with the responsibility of setting both primary and secondary NAAQS for “criteria air pollutants” which can “reasonably be anticipated to endanger public health or welfare” – the primary standards being health-based and the secondary standards being welfare-based. These NAAQS set out the maximum allowable amounts of the criteria pollutants that can be present in the outdoor air. It also requires review of these standards every five years to ensure that they are “requisite to protect public health with an adequate margin of safety” based on available scientific evidence. Ozone, or O3, is a gas composed of three oxygen atoms which can occur in the upper atmosphere or at ground-level. While the ozone in the upper atmosphere is safe and shields the Earth from the sun’s harmful ultraviolet rays, ground-level ozone is a main component of smog and can pose serious health problems as well as environmental harms. In light of these potential adverse health effects, ozone is one of the six criteria pollutants that have been identified by the EPA and therefore require NAAQS.

Once NAAQS are developed for ozone and the other criteria air pollutants, states are required to submit State Implementation Plans (“SIPs”) to the EPA for approval. In these plans, states must identify areas within their jurisdiction as either attainment areas (areas meeting the NAAQS) or nonattainment areas (areas failing to meet the NAAQS) and set out their plan for controlling air pollution from emission sources within their jurisdiction. SIPs include programs for monitoring and modeling air quality, emission inventories and control strategies, and polices and rules regarding the attainment and maintenance of NAAQS. These SIPs must be tailored to meet the attainment dates set out for each criteria pollutant.

What would more stringent NAAQS for ground-level ozone mean for compliance?

If the D.C. Circuit Court finds that the final action of the EPA to not revise the ground-level ozone NAAQS was not reasonable in light of the best available scientific data, it could result in the promulgation of more stringent NAAQS, and in turn more costs for states and industry in order to meet those standards. The revision of the NAAQS would trigger a requirement for states to review their SIPs, which were formed based on the current standards, to ensure that they are adequate to meet the new, more stringent standards. This would require states to review and update the attainment/nonattainment designation of areas under their jurisdiction, and to promulgate new rules where necessary. While this would present challenges to states, the EPA does do its part to help states by publishing a list of rules to help states meet NAAQS as well as guidance memoranda to guide states through the implementation of adequate SIPs. A finding in favor of the environmental groups would also likely result in significant costs for industries to reach compliance with the NAAQS, since they are developed solely based on health and welfare implications, without regard to the cost of compliance. As a result, tightening of the NAAQS usually results in levels that may not be attainable with the technology currently used, and may require hefty investment. So, under stricter standards industries would be required to: (1) purchase or develop new technology to make their emissions more efficient; (2) if a cap-and-trade program is employed, to purchase further rights to emit; or (3) lower their level of production. While these options are beneficial to the environment, they all present significant costs.