A federal appeals court Aug. 23 handed environmental groups a victory by ordering the U.S. Environmental Protection Agency to reconsider its secondary 2015 ozone standard aimed at preventing damage to plants and animals.
The ruling issued by a three-judge panel for the U.S. Court of Appeals for the District of Columbia Circuit rejected arguments by a coalition of states and industry groups that the EPA should have accounted for background levels of ozone in setting standards for the smog-forming pollutant.
In further blows to industry, the court also vacated a special "grandfathering" provision for emissions sources in the EPA's 2015 ozone rule while rejecting claims that the agency is required to consider "socioeconomic and energy impacts" in setting the National Ambient Air Quality Standards, or NAAQS, under the Clean Air Act.
However, the D.C. Circuit sided with the EPA in concluding the agency explained adequately why it revised its primary 2015 ozone standard, which is intended to protect public health and sensitive populations.
Background
Ground-level ozone, the main ingredient in smog, is formed when volatile organic compounds and nitrogen oxides emitted from sources such as power plants, industrial facilities and motor vehicles chemically react in the presence of sunlight. Elevated levels of ozone can cause or exacerbate breathing problems in children, outdoor workers and individuals with existing respiratory conditions while also degrading forest growth and contributing to crop loss.
After a lengthy review involving its Clean Air Scientific Advisory Committee, or CASAC, the EPA in 2015 tightened the NAAQS for ozone to 70 parts per billion, down from the previous level of 75 ppb set in 2008.
Environmental groups including the Sierra Club and Earthjustice challenged the standard at the D.C. Circuit, arguing, among other things, that the EPA set the primary level of acceptable ozone pollution too high to adequately protect sensitive populations and dismissed advice from the CASAC in setting the secondary standard.
Meanwhile, coal mining company Murray Energy Corp. and a coalition of states led by Arizona argued the EPA failed to explain why the less stringent 2008 standard was not already sufficiently protective. They also asserted the rule illegally failed to account for uncontrollable background levels of ozone pollution and argued U.S. Supreme Court precedent required the EPA to consider the "overall adverse economic, social, and energy impacts" of the revised NAAQS.
The Trump EPA eventually declined to revisit the Obama-era rule, leaving the agency to defend the standards against both lines of attack in December 2018 oral arguments.
Wins for the EPA, environmental groups
In upholding the EPA's primary 2015 ozone standard, the D.C. Circuit largely looked to the technical record established by the agency. "As the record makes clear, the [EPA] administrator considered the entire body of scientific evidence available, including clinical studies, epidemiologic evidence, human exposure and health risk assessments, CASAC's recommendations, and over 430,000 public comments," the court noted.
However, the court sided with environmental groups in finding the EPA was wrong to go against the CASAC's advise by setting the secondary standard using a three-year average instead of a one-year average for anticipated seasonal exposure levels. Doing so allowed the EPA to "arrive at a standard that statistically tolerates cumulative ozone exposures in a single growing season that are higher than CASAC's maximum recommended level," the court said.
The court, therefore, remanded the secondary standard back to the EPA, stating the agency either needs to lower that standard even further to protect against unusually damaging exposures or explain why rejecting the CASAC's advice was appropriate.
The court also rejected industry petitioner's attempt to force the EPA to consider costs in setting the NAAQS by invoking the term "appropriate" — a term that appears in the section of the Clean Air Act concerning the NAAQS and a different section of the statute the Obama administration used to issue mercury standards for coal-fired power plants.
Citing the Supreme Court's 2015 ruling in Michigan v. EPA, the petitioners noted the high court found that the Obama EPA had failed to appropriately consider costs to industry in requiring mercury-reducing emission controls at older coal units. But the three-judge panel noted the Supreme Court previously rejected similar arguments for the NAAQS, citing an earlier decision in which the high court found the plain text of the Clean Air Act "unambiguously bars cost considerations from the NAAQS-setting process."
Finally, the court tossed a provision in the EPA's 2015 ozone rule that would have grandfathered construction projects with permits that showed the facilities would comply with the earlier, less stringent 75 ppb standard. Such a provision is exactly what the plain text of the Clean Air Act forbids, the court found, noting the statute prohibits the construction of a "major emitting facility" with emissions that will "cause, or contribute to, air pollution in excess of any" of the NAAQS.
The per curiam opinion was issued by D.C. Circuit Judges Thomas Griffith, Cornelia Pillard, and Robert Wilkins. Murray Energy v. EPA (No. 15-1385)
