On March 9, 2010, the Supreme Court of Wyoming ruled that Basin Electric Power Cooperative can continue with construction of its new Dry Fork Station coal-fired power plant near Gillette, Wyoming.  Finding that the state did not have to require best available technologies for controlling carbon dioxide emissions, the court rejected a challenge to the state-issued air permit brought by Earthjustice on behalf of the Powder River Basin Resource Council and the Sierra Club.

The Plaintiffs, citing a study commissioned by state regulators which indicated that pollution levels could exceed federal limits at the Northern Cheyenne Indian Reservation, had argued that the coal plant would violate the Clean Air Act’s Best Available Control Technology (“BACT”) requirement by using outdated technology, causing added harm to the environment and human health.  The state and Basin Electric argued that the Dry Fork plant’s contribution to the Reservation area’s pollution would be extremely small and that granting the air permit would be consistent with long-standing practices of the Wyoming Department of Environmental Quality and the U.S. Environmental Protection Agency’s interpretation of relevant laws.

The court questioned some of the state’s methodology but ruled that awarding the permit was proper because the agency had “some discretion.”  The justices also ruled that the state correctly applied rules for using BACT and did not have to require BACT for reducing carbon dioxide emissions.