The U.S. Supreme Court returns to work next month and among the cases vying for the justices’ attention is a dispute over the George W. Bush administration’s decision to tighten limits on ozone emissions to the atmosphere.
The Environmental Protection Agency’s March 2008 change to the primary national ambient air quality standard for ozone lowered it by five parts per billion. The agency also set the secondary NAAQS at the same level as the primary NAAQS.
Opponents of that move, who include an industry advocacy organization called Utility Air Regulatory Group and the state of Mississippi, argue in their petition for certiorari that the Environmental Protection Agency set the new primary and secondary NAAQS at a level lower than necessary to protect public health.
Primary and secondary NAAQS for ozone, as well as certain other pollutants, are authorized by the Clean Air Act. A primary NAAQS aims to protect public health, while a secondary NAAQS is intended to advance public welfare.
Both NAAQS for ozone were challenged in the federal court of appeals in Washington, D.C.
The court held last year that EPA acted reasonably in making the change to the primary ozone NAAQS. The three appeals court judges, who ruled unanimously, summarized the scientific basis for the agency’s action:
Of particular relevance here, EPA emphasized new clinical studies, including human exposure studies, showing respiratory effects at ozone levels below 0.08 ppm. EPA also cited new epidemiological evidence suggesting associations between “serious morbidity outcomes” and ozone exposure at levels below 0.08 ppm, as well as risk assessments estimating the effects of various levels of ozone on the population.
The judges, who issued an unsigned opinion, ridiculed industry’s argument that EPA must presume a prior NAAQS to be valid, comparing that assertion to a “funhouse.”
The panel explained that a 2001 Supreme Court decision that requires EPA to set a “requisite” NAAQS, meaning one that is neither too onerous nor to lenient, also allows the agency to take into account scientific uncertainty.
Determining what is “requisite” to protect the “public health” with an “adequate” margin of safety may indeed require a contextual assessment of acceptable risk. Such is the nature of policy. But that does not mean the initial assessment is sacrosanct and remains the governing standard until every aspect of it is undermined. Every time EPA reviews a NAAQS, it (presumably) does so against contemporary policy judgments and the existing corpus of scientific knowledge. It would therefore make no sense to give prior NAAQS the sort of presumptive validity Mississippi insists upon.
Environmentalists, who argued along with a coalition of states, municipalities, and public health organizations that the ozone primary NAAQS was not stringent enough, fared no better before the appeals court judges. They asserted that EPA did not consider health impacts of a standard below 0.075 ppm and that the agency’s 2008 regulation did not include a necessary “margin of safety.”
The judges were not swayed.
EPA finds itself in a situation reminiscent of Goldilocks and the Three Bears. On one side, Mississippi argued that EPA is too stringent with its ozone NAAQS; on the other side, the governmental and environmental petitioners argue that the NAAQS is too lax. But unlike Goldilocks, this court cannot demand that EPA get things “just right.”
One study relied upon by the environmental advocates and their allies had been rejected by EPA on grounds that the sample size was too small; the court found this to be a reasonable decision. The panel similarly turned aside arguments that EPA should have placed more weight on epidemiological studies and that the agency did not act in a manner consist with internal risk assessments.
As for a margin of safety, the D.C. Circuit panel held that EPA has discretion to build that into the NAAQS itself.
The court did agree with arguments that EPA’s 2008 change to the ozone regulation established the secondary NAAQS at too high of a level.
The petition for certiorari pending before the Supreme Court will be granted if four of the nine justices agree to hear the case. The justices are likely to consider the petition at their Sept. 29 conference.
The case is Utility Air Regulatory Group v. Environmental Protection Agency, No. 13-1235.
Before the 2008 regulation, EPA had last changed the ozone NAAQS in 1997. That modification was also subjected to a multi-year litigation journey, being finally upheld by the U.S. Court of Appeals for the District of Columbia Circuit in 2002.
EPA must review NAAQS every five years. If justified by current scientific knowledge relating to public health and welfare impacts of emissions, the agency must change them accordingly.