Supreme Court Narrows Scope of Judicial Review Under NEPA

After nearly two decades of silence, the US Supreme Court on May 29, 2025, weighed in on an issue that has tremendous significance for permitting of complex infrastructure and other development projects—the depth and breadth of the review required under the National Environmental Policy Act (NEPA). In Seven County Infrastructure Coalition v. Eagle County, the Court held that NEPA allows an agency to limit its review to impacts associated with the specific project under consideration and need not evaluate impacts of arguably related but separate activities. In reaching that conclusion, the Court explained “the central principle of judicial review in NEPA cases is deference.”

The case involved the US Surface Transportation Board’s (the Board’s) approval of an 88-mile railroad line intended to connect Utah’s Uinta Basin to the national freight rail network, facilitating the transportation of crude oil to Gulf Coast refineries. The Board’s Environmental Impact Statement (EIS) was challenged for allegedly failing to adequately analyze the environmental effects of increased upstream oil drilling and downstream oil refining.

The US Court of Appeals for the DC Circuit had vacated the EIS and the Board’s approval, concluding the Board failed to take a “hard look” at the project’s impacts because it excluded consideration of the impacts of reasonably foreseeable upstream and downstream projects. The Supreme Court reversed, reasoning that NEPA does not require the Board to consider the environmental effects of other projects that are separate in time or place from the proposed project. The Court further indicated that NEPA allows an agency to focus its review on facts that are salient to its decision-making process and ignore considerations that are not directly relevant to its ultimate decision.

As a practical matter, Seven County is likely to have several important effects going forward, including the following:

• Significantly reducing the circumstances under which courts invalidate federal approvals of infrastructure projects under NEPA.
• Allowing agencies to significantly narrow the scope of impacts considered in an EIS for complex projects. That narrower scope will minimize the degree to which agencies conducting NEPA analysis consider upstream, downstream, or consequential effects, such as climate impacts, potentially expediting approvals of infrastructure projects and saving agencies and project proponents significant costs and time associated with assessing such impacts.
• Further clarifying the substantial deference that is given to agency factual determinations—although the discussion in Seven County was limited to NEPA cases, the Court’s discussion as to why factual determinations are entitled to deference is applicable to other statutes and should give agencies additional comfort about factual determinations they make in other contexts.

BACKGROUND

NEPA, enacted in 1970, is a foundational environmental statute that established a comprehensive framework for ensuring consideration of environmental issues in federal decision-making processes. NEPA requires that federal agencies, prior to undertaking, carrying out, approving or funding any “major Federal action significant affecting the quality of the human environment,” prepare an EIS that considers the “reasonably foreseeable” impacts of the proposed action and a “reasonable range of alternatives.” The information contained in the EIS must afford the agency the ability to assess the potential impacts of its project/activity under consideration and evaluate alternatives. NEPA is a procedural statute—so long as an agency satisfies the procedural requirements, NEPA does not require or speak to any specific substantive result or assign any weight to particular environmental impacts.

Since its passage, NEPA has presented one of the largest permitting hurdles for many developments, including complex infrastructure and energy-related projects. This is due in part to uncertainty regarding the scope of review required under NEPA, both as to the types of impacts that must be considered and the level of detail that must be provided in a legally adequate EIS. This uncertainty frequently leads to litigation and associated delays and costs.

According to the Supreme Court, a divergence had emerged in recent years in the degree to which lower courts scrutinize agency assessments of upstream, downstream, consequential, or aggregate impacts of projects, with some courts mandating detailed analysis of those considerations and some courts taking a more deferential approach. Therefore, the Court found that a “course correction of sorts is appropriate to bring judicial review under NEPA back in line with the statutory text and common sense.”[1]

THE SUPREME COURT’S DECISION

In a unanimous decision with a concurrence, the Supreme Court found that the Board had taken an adequate hard look at the impacts of the proposed project, the 88-mile railroad line, and had therefore satisfied the requirements of NEPA. The Court rejected the DC Circuit’s reasoning that the Board was required under NEPA to consider the impacts of future upstream drilling and downstream refining projects that were the reasonably foreseeable result of construction of the proposed railroad.

Under NEPA, the question is not whether certain upstream/downstream projects are reasonably foreseeable, but rather whether they are part of the “project at hand” or proximately caused by the proposal. The agency has the discretion to establish a “manageable line” between the effects of a proposed project that is studied and those of projects that are separate in time or place, which are not studied. In this case, the Board had found that it need not consider the effects of upstream and downstream projects that will likely result from construction of the proposed railroad because such activities fall under the jurisdiction of another agency or agencies, and the Board could not consider such impacts when rendering a decision on the proposed railroad.

The Court resoundingly agreed with the Board’s reasoning and reversed the DC Circuit’s decision, finding “no rule of reason worthy of that title would require an agency to prepare an EIS’ addressing effects from another project that is separate in time or place from the project at hand—particularly when it would require the agency to speculate about the effects of a separate project that is outside its regulatory jurisdiction.”[2] The Court further held that NEPA does not require an agency to study every effect associated with activities that are not likely to occur “but for” the proposed project. Instead, an agency can focus on the impacts of the current project, not those of future or geographically separate projects. The court also emphasized that NEPA does not require an agency to study impacts where such an analysis cannot play a role in the agency’s ultimate decision on a proposed project. And it held that because NEPA is purely procedural and only requires an agency to prepare “an adequate report,” the agency is assigned the role of defining the scope of the project under review and the depth of analysis needed to make a decision on that project. It emphasized that a court should not second guess an agency’s reasoned determination on these issues or allow NEPA to be utilized as a tool to delay or hamstring projects. 

The decision also emphasized the substantial level of judicial deference that agencies are due in NEPA cases, holding that agencies have discretion to determine the depth and breadth of the environmental review that needs to be undertaken and that this discretion is based upon factual determinations. Courts are required to give deference to agency factual determinations because they fall within the purview of an agency’s expertise. This contrasts with questions of law that are subject to de novo review because, as explained in detail in the Supreme Court’s recent Loper Bright decision, legal determinations fall under the judiciary’s “special competence” as opposed to an agency’s expertise. Accordingly, in reviewing an agency’s EIS, “the only role of a court” is to confirm that the agency has addressed environmental consequences and feasible alternatives as to the relevant project.[3]

The Supreme Court did not extensively address the 2023 amendments to NEPA in the BUILDER Act, in part because the EIS at issue was finalized prior to the amendments. But the majority did explicitly clarify in a footnote that the Court’s analysis “applies to NEPA as amended by the BUILDER Act” and emphasized the BUILDER Act’s provisions placing page and time limits on EISs “strictly prohibit[] an agency’s EIS from going on endlessly.”[4]

IMPLICATIONS

The Supreme Court’s decision represents a significant narrowing of the scope of judicial review in NEPA cases by constraining the circumstances under which lower courts may invalidate a permitting agency’s EIS for failing to adequately consider effects associated with related but separate projects. This “course correction” is likely to be particularly noteworthy in the context of large-scale infrastructure projects and energy projects that tend to have numerous, arguably related activities, as well as a range of indirect impacts, including on climate change, where some lower courts had vacated EISs after concluding they failed to adequately consider the potential impacts of greater greenhouse gas emissions. Going forward, courts will be less able to second-guess an agency’s determination not to consider a project’s potential to induce greater fossil fuel use or its decision not to consider the aggregate impacts of similar projects.

That more deferential judicial review of EISs will in turn affect how agencies conduct NEPA reviews. Agencies will be more comfortable producing EISs that do not account for a broad range of upstream or downstream effects or include an in-depth analysis of indirect effects, as long as the agency provides a reasoned explanation for the scope of the analysis conducted. This could significantly shorten the time and money that it takes for agencies to finalize an EIS and issue a permitting decision, and thereby shorten the time and cost for final approval of infrastructure projects. It could also discourage challengers from litigating claims related to the sufficiency of EISs.

The decision also provides important context to the Supreme Court’s decision in Loper Bright Enterprises v. Raimondo,[5] which overturned the doctrine of Chevron deference and held that the courts, not agencies, should decide “all relevant questions of law” arising out of review of agency action under the APA. Open questions after Loper Bright included how that decision applies to review under other statutes and how the decision applies to mixed questions of fact and law. The Seven County decision answered those questions in the context of NEPA review, clarifying that while courts may analyze the meaning of NEPA’s requirement for “detailed” EISs, determinations regarding what details are warranted for a particular review are factual determinations on which agencies are afforded substantial deference.

Law clerk Lauren Sevigny contributed to this LawFlash.