State of Wyoming v. United States Department of the Interior

The United States Department of the Interior, Bureau of Land Management (bureau) (defendant) had statutory authority to regulate natural-gas production under the Mineral Leasing Act. The bureau promulgated regulations regarding the reduction of the waste of natural gas from oil-and-gas production sites due to venting, flaring, and leaks. In its final rule, the bureau justified the costs of the regulations pertaining to the waste of natural gas by citing benefits of both the prevention of natural-gas waste and the protection of air quality. The bureau estimated that the new regulations would result in benefits of $209 to $403 million per year and costs of $110 to $279 million per year. Although most of the benefits were attributed to environmental benefits that reflected the methane-emissions reductions based on the social cost of methane, a smaller portion of the total benefits were attributed to costs savings from the recovery and sale of natural gas that was prevented from being wasted. The State of Wyoming (plaintiff) filed suit and challenged the final rule as an improper attempt by the bureau to regulate air pollution in excess of its statutory authority. Wyoming argued that the United States Congress delegated the authority to regulate air pollution to the United States Environmental Protection Authority (EPA) and the individual states under the Clean Air Act.