Seven County Infrastructure Coalition et al. v. Eagle County, Colorado et al.: An Important U.S. Supreme Court Decision on the Scope of Judicial Review of NEPA Environmental Impact Statements

On May 29, 2025, the U.S. Supreme Court issued a decision regarding the deference that must be given to agencies under the National Environmental Policy Act (NEPA),¹ which requires federal agencies to prepare an Environmental Impact Statement (EIS) that addresses significant environmental effects of a proposed project and identifies proposed methods to mitigate those effects.² The ruling also clarified how agencies must evaluate potential environmental effects of projects.³

The U.S. Surface Transportation Board (USST Board) issued an EIS in 2021, approving a project to develop an 88-mile railroad that would connect Utah’s Uinta Basin to the national freight network.⁴ The Uinta Basin has a large reserve of waxy crude, which, once extracted, has been historically transported by heated tanker trucks.  The railroad project, if approved, would facilitate and allow increased volumes of petroleum to be transported from the Uinta Basin.⁵ In complying with NEPA, the USST Board set out a detailed statement that addressed related environmental concerns, including potential alternatives to mitigate those concerns. Petitioners before the U.S. Court of Appeals for the D.C. Circuit claimed that the USST Board failed to consider potential future issues of upstream oil drilling and downstream refining of crude oil. The U.S. Court of Appeals for the D.C. Circuit agreed, holding that the USST Board failed to consider the potential harm of future upstream and downstream projects stemming from the railroad.⁶ The Supreme Court held that the D.C. Circuit incorrectly applied NEPA by requiring the USST Board to include the environmental effects that could ensue from increased oil drilling upstream in the Uinta Basin and increased oil refining downstream along the Gulf Coast of Louisiana and Texas in the EIS and did not afford the USST Board appropriate deference.⁷

National Environmental Policy Act

NEPA, enacted in 1970, sets out guidelines for federal agencies to follow when considering the environmental consequences of their actions.⁸ This includes requiring agencies to identify and evaluate whether a project will significantly impact the environment.⁹ If an agency determines that a proposed action will likely have a significant impact on the environment, it must submit an EIS, which outlines all potential concerns related to a proposed project. An EIS is a “detailed” statement that must assess “reasonably foreseeable effects of a proposed action.”¹⁰

The Supreme Court in Seven County Infrastructure highlighted that “NEPA is a procedural cross-check, not a substantive roadblock.”¹¹ The Supreme Court emphasized that, in considering certain projects, agencies should use NEPA to ensure a process for reviewing potential environmental concerns and, ultimately, that NEPA “helps agencies to make better decisions and to ensure good project management.”¹² The Supreme Court further criticized the use of NEPA to slow down and hinder projects.¹³

The Supreme Court’s EIS Review Guidance: Apply Deference 

The Supreme Court posited that some lower courts have taken on an “aggressive role in policing agency compliance with NEPA.”¹⁴ With looming confusion in the courts of appeals regarding what level of review agencies should be subject to in relation to NEPA, the Court clarified the role of courts and indicated: practice deference.¹⁵

Upon review, the Supreme Court cited two mistakes of the D.C. Circuit: first, the D.C. Circuit did not provide the deference required under NEPA, and second, it incorrectly interpreted NEPA to require agencies to make determinations beyond the scope of an EIS.¹⁶ The Court emphasized that “review of an agency’s EIS is not the same thing as review of an agency’s final decision concerning the project.”¹⁷ The Court categorized NEPA as a purely procedural statute. When reviewing an EIS, the Court emphasized that its only role is to “confirm that the agency has addressed environmental consequences and feasible alternatives as to the relevant project.”¹⁸ The Court also emphasized that “[b]ecause an EIS is only one input into an agency’s decision and does not itself require any particular substantive outcome, the adequacy of an EIS is relevant only to the question of whether an agency’s final decision (here, to approve the railroad) was reasonably explained,” under the Administrative Procedure Act.¹⁹ 

The Supreme Court also discussed its landmark decision in Loper Bright Enterprises v. Raimondo, which overturned Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc.²⁰ Citing Loper Bright, the Seven County Infrastructure decision highlights that agency interpretations of statutes are subject to de novo judicial review.²¹ However, the Court noted that many aspects of an EIS that a court may be asked to review do not involve the interpretation of a statute and instead call for deference to agency decisions. For example, although  NEPA requires an EIS to be detailed, whether an EIS is detailed turns on primarily issues of fact and not on the interpretation of the term detailed.²² The Court indicated that the question of whether a report is detailed enough is an issue that should be afforded deference and not “excessively second-guessed by a court.”²³ The Supreme Court summarized its position as follows: “[t]o tie all of this together: When assessing significant environmental effects and feasible alternatives for purposes of NEPA, an agency will invariably make a series of fact-dependent, context-specific, and policy-laden choices about the depth and breadth of its inquiry—and also about the length, content, and level of detail of the resulting EIS. Courts should afford substantial deference and should not micromanage those agency choices so long as they fall within a broad zone of reasonableness.”²⁴

The Supreme Court Also Held that the U.S. Court of Appeals for the D.C. Circuit Erred on the Merits Under NEPA

The Supreme Court also considered that the D.C. Circuit, separate and apart from their lack of deference to the USST Board, was mistaken on the merits because it required the USST Board to address the environmental effects of projects that are separate in time and place from the 88-mile railroad project.²⁵ The USST Board determined that the upstream oil drilling in the Uinta Basin and the downstream oil refining along the Gulf Coast were independent projects from the construction of the 88-mile railroad line.²⁶ The Supreme Court held that the USST Board’s approach complied with NEPA because the textually mandated focus of NEPA is the “proposed action” and not “geographically separate projects that may be built (or expanded) as a result of or in the wake of the immediate project under consideration.”²⁷ The Supreme Court indicated that it is relevant that the USST Board does not regulate “oil drilling, oil wells, oil and gas leases, or oil refineries” and instead approves railroad lines and recalled that “agencies are not required to analyze the effects of projects over which they do not exercise regulatory authority.”²⁸ The Supreme Court concluded that the USST Board properly considered how the construction and operation of the railway would have environmental effects such as, for example, on the habitat of protected species or soil erosion, to name just a few relevant considerations.²⁹

What Does This Mean for Infrastructure Projects Moving Forward?

While providing a guidepost for future NEPA challenges, the “boots on the ground” question remains — what is the practical effect of the Supreme Court's opinion on future infrastructure projects? Arguably, it should curtail future NEPA challenges beyond the scope of the project at hand, thus allowing agencies to prepare and proceed with their versions of adequate EIS under NEPA without delay. This Supreme Court's opinion clearly illustrates that the original intent of NEPA in 1970 did not include giving the courts the power to obstruct infrastructure initiatives.

All federal and cooperating agencies and infrastructure developers looking to advance development projects will be impacted by this ruling. Agencies will no longer be required to examine all potential indirect upstream or downstream impacts resulting from the project at hand. Agencies are now afforded broader discretion in deciding whether a project can continue despite environmental concerns, with the Supreme Court acknowledging deference to these decisions. As a result, project development going forward should move at a faster pace, without the looming fear of protracted NEPA litigation.

Lastly, it is likely that the future of NEPA cases will be unaffected by the Supreme Court’s 2024 Loper Bright decision. Agencies, in reviewing projects under NEPA, should expect greater deference to their factual conclusions. This should translate into developers obtaining greater clarity and a timelier project review and approval process.

As the industry continues to navigate the implications of the U.S. Supreme Court’s recent ruling in Seven County Infrastructure Coalition et al. v. Eagle County, Colorado et al., Buchanan’s Energy, Environmental and Natural Resource attorneys can help you understand how this landmark ruling will shape the future of infrastructure projects.

This article was co-authored by Bryn Horner, Summer Associate, Buchanan.