The Supreme Court opted against hearing a challenge today to U.S. EPA's most recent air regulation aimed at protecting human health from short-term spikes in sulfur dioxide emissions.
In July, the U.S. Court of Appeals for the District of Columbia Circuit held that EPA didn't act unlawfully in setting a new SO2 standard of 75 parts per billion averaged over an hour (Greenwire, July 20, 2012).
The court didn't rule on another part of the challenge on how the rule will be implemented because EPA hasn't finalized its plans.
EPA maintains the one-hour standard was necessary to protect against short-term exposure to SO2, which can aggravate asthma and cause other respiratory problems. The previous limits are 140 ppb measured over 24 hours and 30 ppb measured over a year.
Several states, including Texas and Louisiana, in addition to some industry groups and individual companies, had objected to the rule, raising concerns about how EPA weighed the necessary epidemiological and other health-related data in reaching its conclusions and questioning the increased use of computer modeling that would be required for implementing the rule, instead of traditional monitoring data.
Only mining company Asarco LLC, which owns one of the last main copper smelters remaining in the United States, sought Supreme Court review, although another mining company, Freeport-McMoRan Copper & Gold Inc., filed a brief in support.
Asarco, represented by lawyers from Baker Hostetler, said in its brief that the appeals court, in finding that EPA had the authority to set a standard that allowed for a margin of safety, should have considered whether the new standard was "more stringent than necessary to protect public health."
The company's lawyers argued that the appeals court did not follow the guidance of a 2001 Supreme Court case, Whitman v. American Trucking Associations, in which the court said national ambient air quality standards must be set at a "requisite" level, meaning neither higher nor lower than necessary.
The Obama administration insisted that there was no need to review the appeals court decision, with Solicitor General Donald Verrilli writing that the court had taken into account the Supreme Court's guidance.
Epidemiological studies cited in the final rule "provided strong support from the EPA's conclusion that a standard with a level below 78 ppb is requisite to protect public health with an adequate margin of safety," Verrilli wrote. He also noted that the "requisite" level determination takes into account the need for a margin of safety.
Jeff Holmstead, a former EPA air chief currently at Bracewell & Giuliani, said most observers knew the case was a "long shot" for the Supreme Court. In particular, he said the lower court didn't address the issue of modeling, so the Supreme Court is likely waiting until it does.
"Supreme Court, on that kind of an issue, is almost always going to look for a way to avoid it," he said.
Public health advocates, however, welcomed the court's decision against hearing the case. David Baron, an attorney with Earthjustice, which intervened in the case on behalf of the American Lung Association, said EPA is trying to address SO2 pollution that it has long known has harmful health effects.
"There is a mass of evidence that sulfur dioxide pollution is dangerous, particularly to asthmatics, in these short-term bursts," Baron said. "We've known this for over a decade."