Lower Court Holding
Decision of the District of Columbia U.S. Circuit Court of Appeals
The Clean Air Act requires EPA to promulgate and periodically revise National Ambient Air Quality Standards (NAAQS) for each air pollutant identified by the Agency as meeting certain statutory criteria. For each pollutant, EPA sets a "primary standard," a concentration level "requisite to protect the public health" with an "adequate margin of safety," and a "secondary standard," a level "requisite to protect the public welfare." In July 1997 EPA issued final rules revising the primary and secondary NAAQS for particulate matter (PM) and ozone. Numerous petitions for review have been filed for each rule. We find that the construction of…
