On July 11, 2008, the D.C. Circuit Court of Appeals, in a sweeping decision, rejected one of the Environmental Protection Agency’s major Clean Air Act rulemaking initiatives—the Clean Air Interstate Rule. The ruling came as a surprise to both environmental groups and industry alike, and has, at least temporarily, thrown the status of air quality regulation for several key air pollutants in the Eastern United States into disarray.

Not only does the ruling all but ensure a delay in the air quality and health benefits EPA sought to achieve beginning next year, but it has created significant uncertainty for industry, as many firms had already begun making substantial capital investments in preparation for compliance obligations under the Rule. States are also scrambling to determine how the decision will affect their compliance obligations related to several key air pollutant standards.

This Client Advisory discusses the Clean Air Interstate Rule, the Court’s dismissal of the Rule, the current status of EPA’s National Ambient Air Quality Standards, and the potential impacts the ruling may have on the future of air quality regulation.

D.C. Court of Appeals Rejects EPA Clean Air Interstate Rule