The court of appeals denied petitions for review. The court held that the Environmental Protection Agency did not act contrary to its Clean Air Act authority with respect to Montana air quality when it issued a State Implementation Plan Call and partially disapproved a proposed revision to Montana’s State Implementation Plan for sulfur dioxide emissions, among other actions.
Montana Sulphur & Chemical Company operated a sulfur recovery plant near Billings, Montana. The plant received high-sulfur gas from an adjacent refinery, captured almost all the sulfur, and emitted sulfur dioxide (SO2).
