Course Correction: Supreme Court Steers Toward Greater Predictability in NEPA Reviews

On 29 May 2025, the Supreme Court unanimously declared that a “course correction” was needed for cases under the National Environmental Policy Act (NEPA), holding that a law originally meant to be a procedural check to inform agency decision making has instead grown to paralyze it. Seven County Infrastructure Coalition v. Eagle County reversed a D.C. Circuit ruling that an agency had not done enough in its environmental impact statement (EIS) to review the potential upstream and downstream effects of a proposed railroad line. The Court roundly rejected judicial nitpicking of agency environmental reviews. The Court concluded that agencies are the factual experts when making determinations about environmental impacts, and therefore, should be afforded substantial deference by reviewing courts. Seeking to further streamline the process, the Court signaled that future NEPA actions should be narrower in scope, more concise, and take less time. This change in course will likely result in greater predictability for agencies and developers about the adequacy of NEPA reviews.

NEPA Is Not Meant to Be a “Substantive Roadblock” 

When the federal government approves the development of an infrastructure project, NEPA obligates the relevant agency to complete an environmental review, such as an EIS, to identify significant environmental effects of the project and feasible alternatives to mitigate those effects. The purpose of a NEPA review is to inform agencies and the public about possible environmental consequences of a federal decision. In Seven County, the Court reinforced the principle that NEPA is a procedural cross-check, not a substantive roadblock, intended to inform agency decision making, not to paralyze it.

In 2020, the Seven County Infrastructure Coalition applied to the US Surface Transportation Board (the Board) for approval of an 88-mile railroad line connecting an oil-rich area of Utah to the national freight rail network to allow transportation of crude oil to refineries along the Gulf Coast. As part of its NEPA review, the Board prepared a 3,600-page EIS that noted—but did not fully analyze—the environmental effects of foreseeable increases in upstream oil drilling in Utah and downstream refining of crude oil in the Gulf. The Board approved the railroad line, but the adequacy of its NEPA review was challenged by a county and several environmental groups. The D.C. Circuit agreed with those challengers, finding that the Board should have more extensively considered the indirect upstream and downstream effects in its EIS and vacating the Board’s approval of the railroad line.

In an 8-0 decision, the Court reversed. Justice Brett Kavanaugh, writing for five of the justices, seized the opportunity to recalibrate expectations around NEPA review, explaining that NEPA requires a process for an agency’s environmental review, but it does not dictate the ultimate outcome. There are other “substantive” statutes (such as the Clean Air Act and Clean Water Act) that set emissions and effluent limitations and the like, but NEPA is not one of those statutes. Accordingly, the Court reemphasized that “review of an agency’s EIS is not the same thing as review of the agency’s final decision concerning the project.” And it stressed the need for deference to agency determinations at every level of the process—from assessing the significance of environmental effects, to considering feasible alternatives, to deciding what impacts to review.

As part of its level-setting endeavor, the Court pointed to the 2023 NEPA amendments that were part of the Building US Infrastructure through Limited Delays & Efficient Reviews Act (BUILDER Act), where Congress prohibited agencies’ EISs from “going on endlessly” and imposed 150-page limits and two-year deadlines for EISs.

An Agency’s NEPA Review Should Be Limited to the Project at Hand 

As to the narrow question before it, the Court concluded that the Board did not have to consider upstream and downstream environmental effects that were “separate in time or place” from the railway project.

The Court noted that while indirect environmental effects of the project itself may fall within NEPA’s scope (even if they might extend outside the geographical territory of the project or materialize later in time), the fact that the project might foreseeably lead to the construction or increased use of a separate project does not mean the agency must consider that separate project’s environmental effects. In other words, “the separate project breaks the chain of proximate causation between the project at hand and the environmental effects of the separate project.” This is particularly true where those separate projects fall outside of the agency’s authority, as was the case for the Board, which did not have jurisdiction over upstream oil drilling or downstream oil refineries.

Justice Sonia Sotomayor, along with Justices Elena Kagan and Ketanji Brown Jackson, concurred in the judgment, noting that the majority opinion could have reached the same result without “unnecessarily grounding its analysis largely in matters of policy.” But they too agreed that the D.C. Circuit had gone too far in imposing NEPA duties on agencies.

Courts Must Afford Agencies “Substantial Deference” in NEPA Review 

Emphasizing the limited role of judicial review in NEPA cases, the Court explained that judges should afford “substantial judicial deference” to agencies in NEPA cases. The Court contrasted its decision in Loper Bright Enterprises v. Raimondo,¹ where no deference is owed to agencies’ legal determinations, with the highly factual issues that are at play in an EIS. These include whether a particular explanation in an EIS is detailed enough, the likely impacts of a project, whether those impacts are “significant,” and what alternatives are really feasible. Such choices should not be micromanaged by the courts, so long as they fall within the zone of reasonableness.

Key Takeaways

Going forward, project developers may expect to see:

Shorter and More Concise NEPA Reviews

Agencies, particularly prompted by various Administration priorities, may begin to conduct shorter NEPA reviews, consistent with Congress’ 2023 NEPA amendments. 

Narrower Focus for EISs

Given the Court’s clear direction that judges should defer to the agencies’ decisions about where to draw the line when considering indirect environmental effects, some agencies may streamline the focus of their EISs.

Increased Deference by Courts to Agency NEPA Reviews

The “only role” for a court in an action regarding a deficient EIS is to confirm that the agency has addressed environmental consequences and feasible alternatives to the relevant project. 

Fewer Agency Authorizations Being Vacated on the Basis of an Inadequate EIS

The Court stressed that the “ultimate question” under NEPA is not whether an EIS is inadequate in and of itself, but whether the agency’s final decision is “reasonable and reasonably explained.” Because an EIS is only one component of that analysis, a deficient EIS will not automatically require vacatur of the project’s approval. 

Looking Ahead

The Court has now joined the chorus of criticisms directed at interminable NEPA reviews, with all three branches of government in alignment that the old mode of NEPA must go. Although Congress already sought to streamline the EIS process through the BUILDER Act, given the lag between agency processes and judicial review, the lower courts have yet to internalize what it may mean to review a 150-page EIS conducted in less than two years. This decision also comes at a time when the Administration is seeking to accelerate permitting procedures for domestic energy projects and retooling its NEPA regulations.² Given these shifts, the rigor of judicial scrutiny of such EISs may need to be adjusted. Seven County gives lower courts the leeway they need to make that shift—indeed, it seems to demand it.