In this case, the court considered this issue: Does the National Environmental Policy Act require an agency to study environmental impacts beyond the proximate effects of the action over which the agency has regulatory authority?
The case was decided on May 29, 2025.
The Supreme Court held that the National Environmental Policy Act (NEPA) requires federal agencies to consider the environmental effects of federal projects by preparing a detailed environmental impact statement (E-I-S), but it does not impose substantive limits on agencies’ decisions. NEPA only applies to the environmental consequences of the proposed project itself, not to impacts from future or geographically separate projects that the proposed project might cause. The Surface Transportation Board complied with NEPA by addressing the environmental effects of constructing and operating an 88-mile freight railroad in Utah. NEPA did not require the Board to evaluate environmental impacts from increased oil drilling in the Uinta Basin or increased oil refining along the Gulf Coast—both of which were separate activities outside the Board’s regulatory control. Justice Brett Kavanaugh authored the 5-3 majority opinion of the Court, joined by Chief Justice John Roberts and Justices Clarence Thomas, Samuel Alito, and Amy Coney Barrett.
NEPA’s role is procedural: it ensures agencies and the public are informed about potential environmental effects but does not direct agencies to reject projects with environmental downsides. Courts reviewing an E-I-S must apply a “rule of reason” and defer to the agency’s decisions about the scope and detail of environmental analysis, recognizing that such decisions depend on scientific, technical, and policy judgments that fall within the agency’s expertise. Agencies have discretion to omit analysis of speculative or weakly connected effects—particularly when those effects depend on future decisions by other entities or fall under the authority of other regulators. The Board’s choice not to analyze upstream drilling or downstream refining effects was reasonable because those were not part of the project under review and because the Board lacks the authority to control such activities.
A mere possibility that a project might lead to additional development does not impose an obligation under NEPA to assess all environmental impacts of hypothetical, unrelated projects. Even if a project’s effects are foreseeable, NEPA does not make one agency responsible for evaluating the far-reaching environmental costs of others’ conduct unless those effects are directly caused by the agency’s decision and fall within its regulatory scope. Therefore, the Board’s approval of the railway project, based on an E-I-S that focused on the rail line itself, satisfied NEPA’s requirements.
Justice Sonia Sotomayor authored an opinion concurring in the judgment, joined by Justices Elena Kagan and Ketanji Brown Jackson, agreeing that the Board was not responsible for assessing the environmental effects of oil production because it lacked authority to regulate those downstream and upstream activities.
The opinion is presented here in its entirety, but with citations omitted. If you appreciate this episode, please subscribe. Thank you.
