Supreme Court Curbs the Scope of NEPA Reviews in Landmark Decision: Seven County Infrastructure Coalition v. Eagle County, Colorado

The Court’s decision is especially notable in two respects. First, it clarified that agencies may reasonably focus their environmental reviews on the project before them and need not consider effects of other separate projects, including those that fall within the jurisdiction of other agencies. The Seven County case arose from a decision by the Surface Transportation Board (“STB”) approving a short segment of planned railroad line in Utah, connecting an isolated oil production region to the national railroad grid. The Supreme Court held that, in approving the railway line, the STB had no obligation under NEPA to consider the potential impacts from crude oil production “upstream” of the railroad line, or from “downstream” oil refining or use of the transported oil. This holding marks a sea change in the context of large energy and other infrastructure projects, where the D.C. Circuit and other lower courts have for years required agencies to conduct extensive analysis of other projects and activities occurring “upstream” and “downstream” of the proposed agency action, including ever-expanding reviews of greenhouse gas emissions and climate change associated with activities far outside the acting agency’s jurisdiction.

Second, while that specific holding is extremely important in its own right for a broad range of energy and transportation infrastructure projects — from oil and gas pipelines to electric transmission lines — the Supreme Court’s decision also establishes broader guardrails that will guide environmental reviews by the full spectrum of federal agencies. The Supreme Court emphasized that reviewing courts must afford “substantial deference” to agencies under NEPA and should not second-guess agencies on the myriad technical judgment calls involved in conducting an environmental review, such as identifying potential environmental impacts, evaluating potential alternatives and their feasibility, and determining the scope of a proposed action’s environmental impacts and indirect effects.

Below we summarize the Court’s decision and provide several key takeaways.

Background

NEPA requires federal agencies undertaking “major Federal actions significantly affecting the quality of the human environment” to prepare a “detailed statement” of, among other things, the “reasonably foreseeable environmental effects of the proposed agency action” and “a reasonable range of alternatives to the proposed agency action … that are technically and economically feasible, and meet the purpose and need of the proposal.”³ In other words, NEPA requires agencies to take a “hard look” at the potential environmental consequences of a proposed action. NEPA’s requirements, however, are fundamentally procedural in nature; so long as the agency identifies and discloses relevant environmental information, NEPA does not require a reviewing agency to reach any particular outcome and does not foreclose the agency from approving a project notwithstanding its environmental effects.

The STB regulates the construction and operation of interstate railroad lines. By statute, it approves a new line unless it finds that it is “inconsistent with the public convenience and necessity.”⁴ In 2020, the Seven County Infrastructure Coalition applied to the STB for approval of the Uinta Basin Railway, a proposed 88-mile railroad spur line that would connect the isolated, oil-producing Uinta Basin to the national rail network.

In considering the application, the STB prepared and published a 600-plus-page environmental analysis; with appendices and other technical information the environmental impact statement (“EIS”) exceeded 3,600 pages. In addition to thoroughly considering a broad range of effects of the proposed railway itself, the STB noted the possibility of potential environmental impacts from increased upstream oil drilling in the Uinta Basin and downstream refining of the crude oil that might be carried by the railroad line, but the agency declined to analyze those latter impacts at length. On the potential increase in upstream oil production, the STB determined that the activities in question (e.g., further oil and gas leasing and development) fell outside the agency’s authority and that potential effects were both speculative and attenuated in relation to the railroad line. Similarly, on potential downstream impacts, the STB explained that it lacked statutory authority over the refining or use of crude oil and that it could not reasonably identify the specific destinations and customers to be served by the railroad line. In reaching those determinations, the STB relied on the Supreme Court’s 2004 decision in Department of Transportation v. Public Citizen, in which the Court held that “where an agency has no ability to prevent a certain effect due to its limited statutory authority over the relevant actions,” its NEPA review need not include that effect.⁵

The D.C. Circuit, however, vacated the railroad approval, concluding that the agency’s NEPA review was inadequate on several grounds. Specifically, the court criticized the STB’s failure to more extensively analyze potential increased oil drilling upstream of the project and increased oil refining activities downstream of the project. 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. The court rejected the STB’s argument that because the upstream and downstream activities themselves fell outside of the agency’s regulatory authority, their potential impacts need not be further analyzed as part of the EIS.

The Supreme Court’s Decision

The Supreme Court reversed, in an emphatic opinion that provides important clarity and certainty for agencies conducting NEPA reviews, courts reviewing claims challenging the adequacy of NEPA reviews, and the private parties and other stakeholders who rely on permits and other federal agency actions subject to NEPA.

The Supreme Court found two independent (but related) errors in the D.C. Circuit’s approach.

1. “A course correction” that restores “substantial [judicial] deference” to agency NEPA reviews

First, the Supreme Court reiterated that, contrary to the overly “aggressive” and “intrusive” approach taken by certain lower courts, “the bedrock principle of judicial review in NEPA cases” is “deference” to the agency. The Court emphasized that the “only” role for courts under NEPA is to “confirm that the agency has addressed environmental consequences and feasible alternatives to the relevant project,” and that in doing so a court must afford “substantial deference to the agency.” In practice, such deference will extend to the broad range of issues that arise in NEPA reviews — not only scientific and technical questions long understood to implicate agency expertise, but also the inevitable series of “fact-dependent, context-specific, and policy-laden choices about the depth and breadth of [a] [NEPA] inquiry” that affect the content and length of a NEPA document. These include:

• the range of relevant environmental impacts to be considered and those impacts’ significance;
• the range of potential alternatives and whether a particular alternative is feasible;
• the range and geographic scope of indirect environmental impacts to be considered; and
• the possibility and relevance of other projects separate in time or place (e.g., upstream, downstream, or otherwise) from the proposed action.

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.” The Court pointedly criticized certain lower courts for having transformed NEPA from its original role as a “modest procedural requirement” into a “blunt and haphazard tool” to slow or even stop new infrastructure and construction projects, in a manner that has forced reviewing agencies “to take ever more time … to prepare ever longer EISs.”

The Supreme Court also emphasized that judicial review of an agency’s EIS “is not the same thing as review of the agency’s final decision concerning the project.” Thus, the ultimate question for reviewing courts is “not whether an EIS in and of itself is inadequate,” but rather whether “the agency’s final decision” — e.g., a permit or authorization issued pursuant to the agency’s substantive authority — “was reasonable and reasonably explained.” Thus, even if an EIS falls short in some respect, that deficiency does not necessarily require the Court to set aside (i.e., vacate) the agency’s ultimate approval of the project.

2. Limiting NEPA reviews to the “proposed action” before an agency — not other projects separate in time or space, or outside the action agency’s jurisdiction

Second, and independently, the Supreme Court refocused the required scope of NEPA reviews, holding that NEPA does not require an agency to consider environmental effects of other activities and projects “separate in time or place” from the proposed action, including projects that fall outside the action agency’s authority and that would be initiated by third parties. The Court thus held that (contrary to the D.C. Circuit’s approach) the STB need not consider upstream effects of potential increased oil production by third parties, or downstream effects of increased refining or ultimate use of oil transported on the proposed rail line. Under NEPA, the Court explained, an agency’s required review is focused on the “proposed action” at hand. It need not encompass other potential future projects or activities, or those that are geographically distinct from the proposed action, even if they might be “built (or expanded) as a result of or in the wake of the immediate project under consideration.”⁶

As the Supreme Court explained, those kinds of geographic, temporal, and agency-jurisdictional separations ultimately break the requisite causal chain “between the project at hand and the environmental effects of the separate project.” Under longstanding case law, an agency needs to consider environmental effects under NEPA only if they are reasonably foreseeable and have a “reasonably close causal relationship” to the proposed action. Thus, the mere fact that another project’s environmental effects might be foreseeable is not enough. Nor does it suffice that an agency’s approval of one project might be considered a mere “but-for” cause of other environmental effects; what is required is a “reasonably close causal relationship” akin to proximate cause. So, for instance, even if an agency’s approval of a new airport might lead to the construction of a new stretch of highway, or a new pipeline might lead to a new power plant, the agency approving the airport need not consider the environmental effects of the highway, nor must the agency approving the pipeline consider the effects of the power plant. As applied to the case at hand: “A relatively modest infrastructure project should not be turned into a scapegoat for everything that ensues from upstream oil drilling to downstream refinery emissions.”

Significantly, the Court also held that agencies “are not required to analyze the effects of projects over which they do not exercise regulatory authority.” Thus, because the STB has statutory authority over railroad lines but not oil drilling or refineries, the STB was not required to consider the environmental effects of those activities — which are regulated by other agencies.

The Court did recognize that in some instances, projects may be sufficiently interrelated and close in time and place as to constitute “a single project within the authority of the agency in question.” And the Court recognized that there may be line-drawing questions associated with defining the project being proposed to a specific agency for consideration. Even in those circumstances, the Court emphasized, a court’s review must remain deferential, and it should uphold the agency’s approach so long as it drew a reasonable and manageable line.

Key Takeaways

Far fewer NEPA challenges premised on upstream or downstream effects? As a top-line takeaway, Seven County reaffirms the common-sense principle that under NEPA, an agency can and should focus on the project or action actually proposed to it — e.g., approval of a railroad line, midstream oil or natural gas pipeline, or a highway project. NEPA does not mandate that agencies consider the environmental consequences of other projects that are separate in time or place from the proposed action before the agency, or which fall outside that agency’s regulatory jurisdiction. Just as the Court agreed with the STB that it need not consider the environmental consequences of upstream drilling or leasing decisions or downstream refining activities, so too now should courts uphold an action by FERC approving a pipeline without considering upstream effects of increased gas production, or downstream environmental effects from combusting natural gas in power plants, factories, or homes.

 More broadly, Seven County delivers a strong rebuke of certain lower courts’ tendency to require agencies to consider a broad range of upstream and downstream effects, no matter how speculative or attenuated, especially when the agency has provided a reasonable explanation for why it was drawing a manageable line. The concern has been particularly pronounced in litigation regarding agency analysis of greenhouse gas emissions under NEPA. Much of this caselaw has grown from the D.C. Circuit’s 2017 decision in Sabal Trail, which held that certain downstream greenhouse gas emissions from combusting gas transported in a FERC-jurisdictional pipeline constituted indirect effects under NEPA.⁷ Although Seven County does not say so explicitly, it is difficult to read the decision as anything but a de facto overruling of Sabal Trail and subsequent decisions requiring FERC and other agencies to consider a range of upstream and downstream indirect effects under NEPA.

Restoring NEPA’s role as a “modest,” purely procedural statute: The Court in Seven County took great pains to reiterate that unlike environmental statutes that impose substantive environmental obligations, such as the Clean Air Act or Clean Water Act, NEPA is “purely procedural.” As such, NEPA does not require an agency to weigh or favor environmental consequences in any particular way, or to reach any particular environmental result. The Court, moreover, explained that the adequacy of an agency’s NEPA review is a distinct question from an agency’s obligations under relevant substantive statutes. The Court’s admonition that defects in an agency’s EIS do not necessarily warrant vacatur of an agency’s ultimate action should also provide a welcome check on the hair-trigger approach of some lower courts, which have too readily set aside major infrastructure permits and authorizations based on perceived NEPA foot faults.

Stepping back from the particulars of this case, Seven County can be understood as another link in a chain of Supreme Court cases — like Vermont Yankee, Metropolitan Edison, and Public Citizen — intended to curb lower courts’ unduly aggressive applications of NEPA. The Court was clear that its opinion was intended as “[a] course correction” to “bring judicial review under NEPA back in line with the statutory text and common sense.”

Deference to agencies. The Supreme Court sent a clear and emphatic message to lower courts regarding the substantial deference owed to agencies under NEPA. Going forward, the Court was clear that it expects many technical, scientific, and line-drawing decisions to fall to the discretion of the agency and not be second-guessed by courts. And the Court sought to put an end to the vicious cycle of risk-averse agencies resorting to ever extended review times and ever longer NEPA documents in an effort to survive judicial review.

The Court’s vigorous call for judicial deference under NEPA contrasts sharply with the requirement of independent judicial review of questions of law under Loper Bright Enterprises v. Raimondo.⁸ The Seven County decision builds on, and helps illustrate, guidance from Loper Bright and other cases about the continued role for deferential judicial review of discretionary, technical, and agency policy decisions under the Administrative Procedure Act, notwithstanding independent judicial review on questions of law.

Deference, of course, means that agencies will retain a zone of discretion about the content and scope of their environmental reviews. The Court recognized that an agency’s discretion extends to questions such as the scope of indirect environmental effects, and whether the agency might voluntarily address effects from future or geographically separate projects that may be “initiated (or expanded) as a result of or in the wake of the current project.” But the Court made clear that NEPA does not compel an agency to consider such factors. And it underscored that in the event an agency denies a permit or authorization, an applicant could argue (among other things) that the agency acted unreasonably by “weighing environmental consequences too heavily in light of the agency’s governing statute” or perhaps that the relevant statute “did not allow the agency to weigh environmental consequences at all.” Those kinds of substantive arguments, the Court explained, were unaffected by NEPA.

Separate projects. As explained previously, the Court held that agencies are not required under NEPA to examine the environmental consequences of projects that are geographically or temporally distinct from the proposed action, or that fall outside the agency’s jurisdiction. In doing so, the Court cited examples like a new airport someday leading to a new highway; a new pipeline to a new power plant; or a new housing development to a new subway stop.

The Court cautioned, however, that certain projects may be interrelated or close enough in time or place that they constitute a single project that falls within the agency’s jurisdiction. In that instance, the environmental effects of two nominally separate projects may well warrant consideration in a single environmental document.⁹ But as framed by the Court’s opinion, that rationale would apply only to multiple projects that fall “within the authority of the [single] agency in question.” And even then, a reviewing court should afford deference to the agency’s line-drawing decisions.

The concurrence and the “public convenience and necessity” standard. Justice Sotomayor, joined by Justices Kagan and Jackson, concurred only in the judgment. They would have reached the same result as the Court, but on a narrower ground. In the concurring Justices’ view, the STB did not need to consider upstream or downstream effects of oil production or consumption because the STB lacked statutory authority to reject railroad applications based on how third parties would use the products transported on the railway line. This principle followed from the statutory common-carrier requirements of the Interstate Commerce Act, and the bounds of what factors the Board could properly consider in applying the statutory “public convenience and necessity” standard. In the concurring Justices’ view, the “public convenience and necessity” standard must be understood in the context of the statute’s broader purpose, including the common-carrier requirement.

If adopted by lower courts, the concurring opinion’s gloss on the statutory “public convenience and necessity” standard could have follow-on effects in other statutory contexts involving the same language, notably including Section 7 of the Natural Gas Act (“NGA”), which governs FERC’s approval of interstate natural gas pipeline projects. The concurring Justices’ formulation of the “public convenience and necessity” standard appears narrower than the D.C. Circuit’s expansive understanding of that concept, as articulated in cases such as Sabal Trail.¹⁰ As a result, it could narrow the scope of what kinds of factors FERC must substantively consider under the NGA, with potential similar effects on other similarly worded statutes.

¹ No. 23-975, 605 U.S. ___ (2025).

² Justice Kavanaugh delivered the majority opinion, joined by Chief Justice Roberts and Justices Thomas, Alito, and Barrett. Justice Sotomayor delivered a separate opinion concurring in the judgment, joined by Justices Kagan and Jackson. Justice Gorsuch took no part in the consideration or decision of the case.

³ 42 U.S.C. § 4332(C)(i), (iii).

⁴ 49 U.S.C. § 10901(c).

⁵ 541 U.S. 752, 770 (2004).

⁶ The Court recognized that the potential effects of the proposed action itself may in some circumstances “extend outside the geographical territory of the project or might materialize later in time,” such as run-off from project construction that could affect downstream waters or air emissions from a proposed facility that might travel downwind to other areas. Those effects of the project itself, the Court explained, could constitute indirect effects that are properly within the scope of an agency’s NEPA review. See Seven County Slip Op. 16.

⁷ Sierra Club v. FERC (“Sabal Trail”), 867 F.3d 1357, 1372-75 (D.C. Cir. 2017).

⁸ 144 S. Ct. 2244 (2024).

⁹ See Seven County Slip Op. 19-20.

¹⁰ Compare Seven County Slip Op. 10-11 & n.5, with Sabal Trail, 867 F.3d at 1373.