The Clean Air Act requires the Environmental Protection Agency to set air
quality standards despite scientific uncertainty, environmental groups told a
federal appeals court in a case challenging the agency's decision to retain
existing nitrogen dioxide and sulfur dioxide standards intended to protect the
environment (Center for Biological Diversity v. EPA, D.C. Cir., No.
12-1238, brief filed 11/30/12).
EPA cannot wait for scientific certainty before it sets an air quality
standard, the Center for Biological Diversity, the Clean Air Council, and the
National Parks Conservation Association said Nov. 30 in an opening brief filed in
the U.S. Court of Appeals for the District of Columbia Circuit.
The agency has acknowledged the existing secondary national ambient air
quality standards, which were set in 1971, do not adequately protect the
environment from the indirect effects of acid rain and other forms of acid
deposition. However, in an April 3 final
rule at 40 C.F.R. pt. 50, it retained the existing standards, saying it did
not have enough information to set new standards and is planning a five-year
field pilot program to collect data to help in the future development of a
multi-pollutant standard (77 Fed. Reg. 20,218; 55 DEN A-1, 3/22/12).
“The statute does not limit EPA's standard-setting duty to situations where
data are complete and uncertainties eliminated,” the petitioners told the D.C.
Circuit. “Rather, EPA must use its best judgment to specify, based on its review
of the relevant factors and advice from the Scientific Advisory Committee, a
standard that meets the statutory mandate despite remaining
The petitioners asked the court to vacate the final rule and remand it to the
agency to set a new standard within 14 months.
EPA sets primary national ambient air quality standards to protect public
health and secondary standards to protect the environment and public
The 1971 secondary standards for nitrogen dioxide and sulfur dioxide are
intended to protect the environment against the direct effects of the
pollutants, not the indirect effects of acid rain and other forms of acid
deposition. Nitrogen dioxide and sulfur dioxide are the primary precursors to
The petitioners said the Clean Air Act requires EPA to set secondary
standards that protect against any known or anticipated adverse effects on
The brief said the agency retained standards that it “concedes do not
provide requisite protection against acknowledged harm from deposition of air
pollutants. The agency's violation of the statute could not be clearer.”
The secondary standard for nitrogen dioxide is 0.053 part per million,
averaged annually. The standard for sulfur dioxide is 0.5 ppm, averaged over
three hours and not to be exceeded more than once annually.
EPA Administrator Lisa Jackson signed the final rule March 20 under the terms
of a 2007 consent decree that resolved a lawsuit brought by the Center for
Biological Diversity over EPA's inaction on reviewing the standards (Center
for Biological Diversity v. Jackson, D.D.C, No. 05-1814, notice filed
In a 2011 policy
assessment, EPA staff recommended that revisions to the secondary standards
be based on maintaining an acid-neutralizing capacity in the environment between
20 microequivalents and 75 microequivalents per liter.
The petitioners also argued that EPA did not adequately explain why data gaps
and modeling uncertainties are so profound to prevent it from setting a
standard. The brief said neither EPA's staff nor its independent science
advisers, the Clean Air Scientific Advisory Committee, recommended against
setting a new standard.
“Put simply, the Administrator's excuses cannot be squared with the fact that
the Scientific Advisory Committee and EPA's own staff explicitly laid out, in
great detail, an ample basis for setting a standard providing requisite
protection from aquatic acidification,” the brief said.
The brief said EPA staff analyzed acid-sensitive regions at various forms and
levels in a range of the possible standards and found between eight and 25
regions would not meet the standard.
By Jessica Coomes
The Nov. 30 opening brief in Center for Biological Diversity v. EPA,
filed in the U.S. Court of Appeals for the District of Columbia Circuit, is
available at http://op.bna.com/fcr.nsf/r?Open=jcos-92mr6d.