/>iOverview
On May 29, 2025, the U.S. Supreme Court issued a significant decision clarifying the scope of environmental review required under the National Environmental Policy Act (“NEPA”) for major infrastructure projects. The Court recognized and reined in what infrastructure practitioners have long understood: NEPA strayed far beyond its “procedural” and “informational” roots to become an obstruction to infrastructure projects across the country.
As brief background, a project developer filed an application with the Surface Transportation Board (“STB”) for a proposed 88-mile railroad line in Utah. The STB, pursuant to its NEPA requirements, issued a 3,600-page environmental impact statement (“EIS”) analyzing the environmental effects of the project and ultimately approved the railroad line. Groups challenged the STB’s approval, and the D.C. Circuit vacated the STB’s decision, ordering the STB to analyze the potential “upstream” impacts of the proposed railroad, which included possible increased oil and gas drilling activities in Utah, and potential “downstream” impacts of the railroad, such as increased oil refining in Texas.
The Supreme Court reversed the D.C. Circuit Court’s prior decision, finding that the D.C. Circuit: (1) did not afford substantial deference to the STB required in NEPA cases, and (2) incorrectly ordered the STB to review the environmental effects of projects separate in time and place from the actual 88-mile railroad under consideration.
Substantial Deference to Agencies in NEPA Reviews
First, the Court emphasized that lower courts should provide deference to agencies when evaluating the agencies’ NEPA review of a project. This is because an agency’s environmental review will include “a series of fact-dependent, context-specific, and policy laden choices about the depth and breadth of [the agency’s] inquiry….” Courts should thus afford agencies “substantial deference” when the agencies’ choices are “within a broad zone of reasonableness,” described further as “a rule of reason.”
Reasonably Close Causal Relationship to the Project
Second, the Court reined in the scope of what the environmental review must consider, i.e., the “proposed action.” Future or geographically separate projects that may be built or expanded are not generally part of NEPA’s scope. The Court characterized this finding in legal terms as “proximate causation,” those effects that have a reasonably close causal relationship between the project at hand and the environmental effects of other projects would be included in a NEPA review.
The Court rejected, however, a “but for” causal relationship, providing that even though environmental effects may be reasonably foreseeable, such as increased oil and gas development from the proposed railroad line, lower courts should not second guess an agency’s decision to exclude from NEPA review projects that are separate in time or place from the actual project being considered. The Court noted that the agency may draw a “manageable line” for what it reasonably concludes should be considered. Summarizing this point, the Court stressed that “[a] relatively modest infrastructure project should not be turned into a scapegoat for everything that ensues from upstream oil drilling to downstream refinery emissions.”
Conclusion
While a significant victory for project proponents, this decision does not foreclose the scope of the extent of an environmental review in a NEPA EIS beyond the confines of the actual project. Project proponents should evaluate potential environmental impacts beyond the actual project and analyze whether or not those environmental impacts would be considered “reasonable,” for example:
- Does the agency that is making the decision regulate the potentially foreseeable environmental effects?
- Are the potentially foreseeable environmental effects geographically separate from the actual project?
- Are the potentially foreseeable environmental effects a hypothetical future event?
- Are the potential environmental effects speculative?
