The U.S. Supreme Court has unanimously ruled to limit the scope of environmental reviews required for major infrastructure projects under the National Environmental Policy Act (NEPA), fundamentally reshaping how federal agencies must assess the environmental impacts of such projects.

The case, Seven County Infrastructure Coalition v. Eagle County, Colorado, centered on the proposed construction of an 88-mile railway in Utah’s Uinta Basin. The railway is intended to connect the oil-rich region to the national rail network, facilitating the transport of crude oil to refineries in Louisiana, Texas, and beyond. After the Surface Transportation Board (STB) approved the project in 2021, following a comprehensive 3,600-page Environmental Impact Statement (EIS), a coalition of environmental groups and Eagle County, Colorado, challenged the decision. They argued that the EIS failed to sufficiently analyze the environmental effects of increased upstream oil drilling and downstream oil refining that could result from the railway’s operation.

The U.S. Court of Appeals for the D.C. Circuit sided with the challengers, vacating both the EIS and the STB’s approval, and ruling that NEPA required the agency to consider these broader, indirect impacts.

In an 8-0 decision (with Justice Neil Gorsuch recused), the Supreme Court reversed the D.C. Circuit, holding that NEPA does not require federal agencies to analyze the environmental effects of projects that are “separate in time or place” from the one under review. Writing for the majority, Justice Brett Kavanaugh emphasized that NEPA is a procedural statute focused on ensuring agencies consider the environmental impacts of the specific project at hand, not on mandating analysis of every conceivable downstream or upstream effect.

The Court found that the STB’s EIS, which addressed the direct environmental effects of the railway itself, was sufficient under NEPA. The agency was not required to analyze the potential environmental impacts of increased oil drilling in the Uinta Basin or additional refining along the Gulf Coast, as those activities are regulated by other agencies and are not directly under the STB’s authority.

Justice Sonia Sotomayor, joined by Justices Kagan and Jackson, concurred in the judgment but wrote separately to clarify that the result was dictated by Supreme Court precedent. She agreed that the STB lacked the statutory authority to reject the railway based on harms caused by third parties using the rail line, and therefore was not required to consider those impacts in its NEPA review.

The decision marks a significant shift in the scope of NEPA obligations, narrowing the range of environmental effects that agencies must consider and reinforcing judicial deference to agency expertise. Industry groups and infrastructure advocates welcomed the ruling, arguing that it will streamline the approval process for major projects and prevent what they see as unnecessary delays caused by expansive environmental reviews.

Environmental organizations, however, warn that the ruling could limit the government’s ability to fully assess and mitigate the broader environmental consequences of large infrastructure projects, particularly those related to climate change and fossil fuel development.

The ruling also reflects a broader bipartisan consensus that NEPA reviews have become too burdensome, a sentiment echoed in recent legislative reforms that now cap EIS length and set strict deadlines for their completion.