ELR Citation: ELR 20645
No(s). 97-1686 (D.C. Cir. Mar 2, 1999)

The court remands for further explanation the U.S. Environmental Protection Agency's (EPA's) rule establishing floor performance standard requirements for new and existing medical waste incinerators (MWIs) under the Clean Air Act (CAA). The court first holds that EPA's use of permit and regulatory data rather than performance data for existing MWIs did not violate the CAA's requirement that the performance standards be based on emissions limitations achieved. The use of such information is permissible if it allows a reasonable inference as to the performance of the top 12 percent of existing MWIs. Further, as long as there is a reasonable basis for believing that some of the best performing 12 percent of MWIs are uncontrolled, EPA may include data points giving a reasonable representation of the performance of those units in its averaging. The court then holds, however, that EPA failed to explain why it believed that the combination of regulatory data and uncontrolled values gave an accurate picture of the relevant MWIs' performance. EPA has said nothing about the possibility that MWIs might be substantially overachieving the permit limits. Also, EPA never gave any reason for its apparent belief that MWIs that were not subject to permit requirements did not deploy emission controls. Thus, the court remands the floor determinations for existing units.

The court then holds that the record failed to explain EPA's approach in setting floor levels for new MWIs. In the absence of the Agency's explanation of both the decision to increase the levels and the choice of method for determining the increases, the court cannot decide if EPA's methodology was proper. Last, the court rejects claims that EPA failed to consider pollution prevention measures and non-air quality health and environmental effects of MWI pollution in establishing the MWI standards.

Counsel for Petitioners
James S. Pew
Earth Justice Legal Defense Fund
1625 Massachusetts Ave. NW, Ste. 702, Washington DC 20036
(202) 667-4500

Counsel for Respondents
Steven E. Rusak
Environment and Natural Resources Division
U.S. Department of Justice, Washington DC 20530
(202) 514-2000

Before Wald and Henderson, JJ.