By Shane Robinson
April 15, 2002

The District of Columbia Circuit Court on March 26th rejected all remaining challenges to the Environmental Protection Agency's 1997 national ambient air quality standards (NAAQS) for fine particulate matter (the PM2.5 standard) and ground'level ozone (the 8-hour ozone standard). The Court rejected industry claims that EPA acted arbitrarily in setting the NAAQS. In a unanimous decision, the three'judge panel found that EPA "engaged in reasoned decision'making" in establishing levels that protect public health and the environment.

Legal battles on this issue go back to 1991 when the American Lung Association first sued EPA to push the agency to move forward on establishing new air standards. Once EPA established new standards for ozone and particulate matter in July 1997, the agency was sued by industry groups lead by the American Trucking Association.

The industry groups, in addition to accusing EPA of acting arbitrarily in establishing the new NAAQS, argued that the Clean Air Act itself was unconstitutional because it violated the non'delegation clause of the Constitution. However, in February 2001, the U.S. Supreme Court ruled unanimously that the 30'year'old Clean Air Act was indeed constitutional but left other issues to be resolved by the D.C. Circuit Court.

This final decision by the D.C. Circuit Court on the legality of the new NAAQS clears the way for EPA to move forward on developing plans to implement the new NAAQS (see related 3/18/02 article at www.usmayors.org/CleanAir). However, once those plans are finalized, many expect EPA to be sued again - either by industry groups seeking to further delay implementation of the standards, or by environmental and public health groups arguing the plans are too lax.