Supreme Court Seven County Decision Reiterates “Bedrock” Principle of NEPA Review: Deference

On May 29, 2025, the U.S. Supreme Court issued its opinion in Seven County Infrastructure Coalition v. Eagle County, No. 23-975 (Seven County), clarifying the scope of federal agencies’ environmental-review obligations under the National Environmental Policy Act (NEPA). In an 8-0 opinion, the Court held that the lower court erred when it found a violation of NEPA and vacated the underlying agency decision on the grounds that the environmental impact statement (EIS) should have considered the upstream and downstream impacts of the proposed action in greater detail. Justice Kavanaugh wrote the majority opinion, stating that a “course correction of sorts” was necessary “to bring judicial review under NEPA back in line with the statutory text and common sense.” Writing in concurrence with the judgment, Justice Sotomayor disagreed with the majority’s characterization of its holding, instead stating that the result “follows inexorably from our precedent.” Where the Court itself disagrees over the extent to which its opinion represents a sea change in NEPA litigation, we anticipate that lower courts and litigants, too, will have differing views. Additional detail regarding the Seven County opinion and its potential effects are discussed further below. See Seven Cnty. Infrastructure Coal. v. Eagle Cnty., Colorado, No. 23-975, 2025 WL 1520964, at *1 (U.S. May 29, 2025).

In Seven County, the Seven County Infrastructure Coalition – a group of seven Utah counties – applied to the U.S. Surface Transportation Board (Board) for approval of the Uinta Basin Railway, a proposed 88-mile railroad spur line that would connect the oil-producing Uinta Basin to the national rail network. The Board prepared a 3,600-page EIS analyzing the impacts of the railway’s construction and operation. The EIS noted, but did not fully analyze, the potential environmental effects of increased upstream oil drilling in the Uinta Basin and increased downstream refining of crude oil along the Gulf Coast. The Board subsequently approved the railroad line, concluding that the project’s transportation and economic benefits outweighed its environmental impacts.

Opponents appealed the Board’s decision to the D.C. Circuit Court of Appeals, and the D.C. Circuit vacated the Board’s EIS and its decision approving the railroad. The D.C. Circuit ruled that the EIS did not sufficiently consider the potential environmental effects of upstream and downstream oil and gas projects. In the D.C. Circuit’s view, those potential upstream and downstream impacts were reasonably foreseeable consequences of approving the railroad line and thus fell within the agency’s NEPA obligations to consider fully.

Petitioners asked the Supreme Court to review whether NEPA required the Board to study the environmental impacts of oil wells and refineries that lie outside the Board’s regulatory authority. The Court granted review to decide that question and reversed.

The Court identified two errors in the D.C. Circuit’s decision. First, the Court held that the lower court did not apply the substantial judicial deference required in NEPA cases to the Board. Second, the Court found that the D.C. Circuit erroneously ordered the Board to address the environmental effects of projects separate in time or place from the construction and operation of the railroad line.

Confirming Substantial Deference to Agency NEPA Reviews

The Supreme Court explained that courts should not “micromanage” agency NEPA reviews so long as the agency’s choices fall within “a broad zone of reasonableness.” Id. *2. The Court noted that some federal courts have not applied NEPA with the level of deference demanded by the statutory text and the Court’s previous decisions. In the Court’s view, the courts’ rulings have “slowed down or blocked many projects and, in turn, caused litigation-averse agencies to take ever more time and to prepare ever longer EISs for future projects.” Id. at *8.

The Court confirmed that NEPA is a purely procedural statute; the statute requires federal agencies to consider the environmental effects of federal projects by preparing a detailed EIS, but it does not impose substantive limits on agencies’ decisions to build, fund or approve a proposed project. The Court highlighted the “rule of reason” from Department of Transportation v. Public Citizen, 541 U.S. 752, 770 (2004) (Public Citizen), highlighting that an agency’s “predictive and scientific judgments” in assessing impacts and determining the scope of environmental review is subject to substantial deference. Indeed, the opinion states that, when assessing agency decisions like these, a reviewing court must be at its “most deferential.”

The majority’s reasoning in Seven County is in contrast to its recent Loper Bright Enterprises v. Raimondo, 603 U.S. 369 (2024) (Loper Bright) decision holding that agencies are not entitled to deference on issues of statutory interpretation. The Seven County decision suggests that, currently, the Court does not intend to further extend Loper Bright to factual issues.

Importantly, the Court clarified the circumstances in which a reviewing court should vacate an agency decision when it determines an EIS is deficient: “Even a deficient EIS does not necessarily require vacating an agency’s project approval, absent reason to believe that the agency might disapprove the project if it added more to the EIS.” This holding may wind up being the most influential of the Seven County decision, as it adds clarity on when vacatur is appropriate – an issue where jurisprudence was previously lacking.

Restricting NEPA Reviews to the Proposed Action at Issue Before an Agency

The Court explained that the mere prospect that a project may lead to additional development does not impose an obligation on a reviewing agency under NEPA to assess all environmental impacts of hypothetical, unrelated projects, particularly if those other projects are outside the agency’s jurisdiction. Notably, the Court specified that reviewing courts may not “invoke a but-for causation or mere foreseeability to order agency analysis of the effects of every project that might somehow or someday follow from the current project.” The Court’s reasoning differs from the standard applied by many federal agencies in determining the scope of environmental review and may limit the scope of environmental review for future federal actions.

The Concurrence

Justice Sotomayor, joined by Justices Kagan and Jackson, concurred in the judgment. Justice Sotomayor’s concurrence – which is firmly grounded in NEPA precedent – observes that NEPA requires agencies to consider the environmental impacts for which their decisions would be responsible. Justice Sotomayor goes on reason that the Court’s decision in Public Citizen precludes the respondents’ argument that the Board should have analyzed environmental impacts which it could not lawfully prevent. The Board, in the opinion of the concurring Justices, correctly understood the scope of its decision-making authority in determining that it would not be responsible for the consequences of upstream oil drilling or downstream refining of crude oil from the Railway because it could not lawfully consider those consequences as part of the approval process.

What Are the Implications of the Court’s Ruling?

The implications of the Seven County decision remain to be seen. Although the majority characterizes its opinion as a “course correction,” the opinion’s underlying analysis could also be interpreted as a relatively straightforward application of NEPA and prior case law, as the concurrence suggests. In our view, regardless of how the opinion is interpreted, there are four important takeaways:

• First, the Court’s decision reaffirming that agency deference is required under NEPA appears to indicate that the Court does not currently intend to extend Loper Bright to limit agency discretion on factual matters.
•  Second, the Court’s holding regarding when vacatur is appropriate could be significant for projects – even if an EIS is determined to be deficient, the opinion provides relatively straightforward direction to lower courts that vacatur should not be the default, which may allow projects to proceed even if an agency is required to supplement an EIS on appeal.
• Third, the decision’s analysis that courts should not impose a “but-for” causation analysis when assessing what upstream and downstream impacts should be studied in an EIS could provide helpful clarification to federal agencies and have the effect of somewhat limiting the scope of an EIS in future projects. The reasoning could also limit future litigation, in that the extent to which upstream and downstream impacts should be studied has been highly litigated over the years.
• Fourth, the decision does not acknowledge that the federal regulations implementing NEPA promulgated by the Council on Environmental Quality (CEQ) have been held invalid and are being repealed. The repeal of the CEQ regulations could, in fact, be a sea change in NEPA implementation and regulation, and adds substantial uncertainty to the implementation of NEPA going forward.

For more information, contact Ryan Cox, Haley Waller Pitts or Shantal Pai.