Overview

The U.S. Supreme Court’s decision in Seven County Infrastructure Coalition v. Eagle County, Colorado represents a significant change in how courts should review the adequacy of an environmental impact statement (EIS) prepared under the National Environmental Policy Act (NEPA).

In the decision of a five-justice majority, the Court found that: (1) when analyzing environmental impacts, an agency need not analyze impacts far beyond the project area nor the impacts of separate projects over which the agency has no jurisdiction; (2) courts must give greater deference to and stop interfering with the agency’s decision regarding what impacts to analyze; and (3) courts should not invalidate a project permit or approval unless it is likely that agency, on remand, will not approve the permit next time around (as opposed to fixing the procedural error the court identified).

Three Justices concurred in the judgment, indicating that the judgment flowed “inexorably” from the Court’s prior NEPA precedents, though not disputing much of the majority’s analysis. Coupled with the majority’s explicit reference to the 2023 NEPA amendments as codifying prior caselaw, this makes Seven County more of a consolidation than a transformation of the law. The Court’s emphasis on causation has implications for other environmental laws, including the Clean Water Act and Endangered Species Act.

This decision has the potential to substantially reduce permitting risk for project developers, both by reducing the time and effort expended in NEPA compliance and in reducing litigation risk once permitting is complete.

Background

The case involves an appeal from a D.C. Circuit Court of Appeals decision to vacate and remand the approval of an 88-mile railroad project to transport petroleum extracted from Utah’s Uinta Basin to the national railway system. As discussed in further detail here, the D.C. Circuit faulted the Surface Transportation Board (STB)’s environmental review for failure to analyze reasonably foreseeable upline and downline impacts, such as impacts from increased drilling and oil-train traffic in Utah and Colorado as well as increased oil refining on the Gulf Coast. Because the STB had disclosed in its EIS that crude produced in Utah would be refined in Louisiana and Texas, the D.C. Circuit ordered STB to consider impacts to Gulf Coast communities from crude oil refining and transport to the national railway system.

For additional background, please see our previous articles:

A Period of Uncertainty for NEPA, and a Blank Slate for the Supreme Court‎, published 11/18/2024

A More Modest Procedure? — The Supreme Court Considers Limiting the Scope of ‎‎“Reasonably Foreseeable” Impacts in NEPA Analysis, published 12/10/2024

NEPA’s Future Comes Into View with New Guidance and Rule Recission, published 2/24/2025

Holding

The Supreme Court reversed, determining that (1) when reviewing whether an EIS complies with NEPA, courts should afford substantial deference to the agency’s decision as to what constitutes a reasonably foreseeable environmental impact of the project under review; (2) an agency need not consider environmental effects that do not have a reasonably close causal relationship to the proposed project; and (3) an agency need not consider environmental impacts outside of its statutory authority. Justice Kavanaugh penned the Opinion of the Court, joined by Chief Justice Roberts, and Justices Barrett, Alito, and Thomas. Justice Sotomayor concurred in the judgment, joined by Justices Kagan and Jackson. Justice Gorsuch was recused.

Implications

Deferential Standard of Review. The opinion imposes limits on judicial review of an agency’s NEPA analysis and adds deference to agency decision-making as a protective layer on the existing arbitrary and capricious standard of review.  In assessing whether an agency action to approve a project is arbitrary and capricious due to a deficiency in an EIS, the reviewing court should take into account that an EIS is only one input into an agency’s decision. The adequacy of an EIS is “relevant only to the question of whether an agency’s final decision . . . was reasonably explained.”

“To 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.”

The decision reinforces the Court’s 2004 Opinion in Public Citizen and its holding that agencies determine the scope of the environmental review with courts deferring to the agency so long as the agency drew a reasonable and “manageable line.” In a rebuke of lower courts, the decision reiterates that all lower courts should adhere to the principles of Public Citizen, reining in expansive, judicially mandated, and burdensome requirements on agencies to consider an array of environmental effects.

Limited Geographic and Temporal Scope of Analysis.  The decision limits the temporal and geographic analysis of environmental effects in a NEPA analysis. Agencies are not obligated to evaluate environmental effects that are separate in time or place from the specific railroad project in question. Relying on proximate causation principles articulated in Public Citizen—that an agency need not analyze an effect where there is no “reasonably close causal relationship” to the project at hand—the majority held that potential effects from future projects, such as projects located in different geographic areas, and projects that fall outside the agency’s jurisdiction often break the causal chain and do not need to be taken into account in NEPA analyses. The Court took pains to emphasize that indirect or associated effects may still need to be considered but also noted that the agency will generally have discretion to draw the line.

No Need to Include Separate Projects. An EIS does not need to analyze impacts associated with other projects that are wholly independent from the project at issue. “The proper judicial approach for NEPA cases is straightforward: Courts should review an agency’s EIS to check that it addresses the environmental effects of the project at hand. The EIS need not address the effects of separate projects.”

Vacating a Permit Not Broadly Required By NEPA Deficiencies. Even if an EIS fails, the deficiency may not require a court to vacate the agency’s approval of the project unless the deficiency would cause the agency to disapprove the project. This holding could allow projects to avoid the costly delays associated with the vacatur of an agency’s approval due to NEPA deficiencies and instead allow the project to continue moving forward while the NEPA deficiencies are corrected. This follows the so-called “Allied-Signal” test that most courts use when deciding whether to vacate an agency action.

Reducing Incentives to Litigate? The decision emphasizes that NEPA is a procedural statute the purpose of which is to inform agency decision-making and not a statute that requires agencies to make substantive changes to a project to account for environmental impacts.  The Court criticized the use of NEPA to obstruct development, identifying that “NEPA has transformed from a modest procedural requirement into a blunt and haphazard tool employed by project opponents … to try to stop or at least slow down new infrastructure and construction projects.”  With the threat of permit vacation largely removed, project opponents may be less successful in using litigation delays as a tactic to kill projects. Further, with the decision’s call for courts to refrain from second-guessing agency determinations regarding the level of detail in a NEPA analysis, NEPA has the potential to become more streamlined.

This article summarizes aspects of the law. This article does not constitute legal advice. For legal advice for your situation, you should contact an attorney.