ELR Citation: ELR 20246
No(s). 05-1353 (D.C. Cir. Dec 12, 2006)

The court upheld the U.S. Environmental Protection Agency's (EPA's) regional haze rule, which was promulgated to remedy visibility impairment in national parks and wilderness areas. The rule requires that under specified circumstances, states impose best available retrofit technology (BART) on any BART-eligible sources. The rule also permits states to reduce haze by alternate means, including a regional approach, so long as the alternative would improve visibility more rapidly than under BART. Industry groups argued that the rule inappropriately requires states to apply BART to too many sources, whereas environmental groups argued that the rule improperly allows states to exempt too many source sfrom BART. The court, however, concluded that EPA's interpretation of Clean Air Act §169A in enacting the rule was reasonable and rejected both challenges.