Federal judges today upheld U.S. EPA's ozone air standard in a challenge from public health groups that said the agency ignored a scientific consensus pointing to a stricter limit.
However, the U.S. Court of Appeals for the District of Columbia Circuit also sent EPA's secondary National Ambient Air Quality Standard, or NAAQS, back to the agency for review, holding that the agency erred in simply setting the secondary standard identical to the primary standard of 75 parts per billion.
The secondary standard is intended to protect public welfare, including vegetation, soil, water and related wildlife.
Environmental groups had pointed to documents that EPA's Clean Air Scientific Advisory Committee, or CASAC, provided to the agency before George W. Bush's administration set both standards at 75 ppb in 2008. CASAC recommended a primary standard of between 60 and 70 ppb.
But in a 48-page order for the court, the three-judge panel ruled that the agency was not required to adopt the CASAC recommendations. Further, the judges noted that it is the agency's call when there remains some scientific uncertainty.
"Although both CASAC and EPA must exercise public health policy judgment when confronted with scientific evidence that does not direct it to a specific outcome, it is to EPA's judgment that we must defer," they wrote. "EPA's invocation of scientific uncertainty and more general public health policy considerations satisfies its obligations under the statute."
The closely watched case, Mississippi v. EPA, was put on hold in early 2009 after President Obama took office. EPA then pledged to reconsider the Bush-era standard.
But Obama punted on setting a new standard in September 2011, rejecting EPA's proposal that would have lowered the primary standard to between 60 and 70 ppb (Greenwire, Sept. 7, 2011).
Attention then turned back the D.C. Circuit case, which featured environmental groups claiming the Bush-era standard was insufficient for protecting public health as well as industry groups and states that said it was too stringent.
Ozone is a major component of smog, and the advocates -- including the Natural Resources Defense Council, American Lung Association and Environmental Defense Fund -- argued that a trove of scientific research indicates that ozone at a level of 75 ppb poses significant health threats, particularly to vulnerable populations such as children and pregnant women.
They also noted that EPA's ozone NAAQS is the foundation of many of the agency's air programs -- including efforts to address pollution that drifts across state lines. So if the ozone NAAQS is too weak, the groups argue, those programs are also failing to protect public health.
Frank O'Donnell, president of Clean Air Watch, called the ruling a "disappointment."
"But it does not diminish the need to update the ozone health standard, since more recent science demonstrates the current standard is too weak to protect people's health," he said.
At oral arguments last November, the three-judge panel appeared sympathetic to the advocates' arguments with regard to the advisory panel (Greenwire, Nov. 16, 2012).
Environmentalists took some consolation today in the panel's secondary standard ruling. Turning to recent D.C. Circuit precedent, the court held that EPA cannot simply set the secondary standard at the same level as the primary standard without providing scientific justification.
It "is insufficient for EPA merely to compare the level of protection afforded by the primary standard to possible secondary standards and find the two roughly equivalent," the panel said. "Because EPA failed to determine what level of protection was 'requisite to protect the public welfare,' EPA's explanation for the secondary standard violates the Act."
The panel was composed of Judges Janice Rogers Brown and Thomas Griffith, both George W. Bush appointees, and Judge David Tatel, who was put on the bench by President Clinton.
They sent the secondary standard back to EPA for further explanation or reconsideration but left the current standard in place in the meantime, as was requested by the environmental groups.
'Minimal' practical impact
It is unlikely the ruling will have much effect on EPA's ozone deliberations, agency watchers said.
EPA is already reviewing the standards as required by the Clean Air Act every five years. Most expect the agency to set a standard between 60 and 70 ppb, and EPA is supposed to issue its proposal by the end of this year and finalize it next year.
A reconsideration of the secondary standard is already part of that process, said John Walke of the Natural Resources Defense Council, so the impact of the court ruling will be "minimal."
"EPA is in the midst of a process that should result in stronger ozone health and welfare standards based on the latest research and best available science," Walke said.
"Former EPA Administrator Lisa Jackson and her assistant administrator for air, now Administrator Gina McCarthy, had already proposed to strengthen the ozone health standards to between 60 and 70 ppb before the president intervened to delay that process. I expect the current 75 part per billion ozone standard will be substantially strengthened," he said.
Many health advocates, however, expect EPA's schedule for the new standards to slip into 2015, and several groups are filing litigation to finalize a deadline for the agency.
Click here for the ruling.