As we look forward to 2026, we wanted to share with you a series of blogs to recap of some of the worst U.S. Supreme Court decisions that will shape our ability to protect our environment for decades to come. (Blog 3/4) 

Supreme Court Says Agencies Don’t Have to Chase Every “What If” in Environmental Reviews 

When the federal government wants to build or permit something big, like a railroad, pipeline, or highway, it has to follow the National Environmental Policy Act, or NEPA. NEPA’s main rule is simple: before starting, the agency has to study how the project could affect the environment and determine whether that impact is “significant.” If so, it must write up an Environmental Impact Statement (EIS), looking at those impacts and mitigation that could lessen them. But NEPA doesn’t tell them what decision to make. It just makes sure they have “taken a hard look” before moving forward. 

In this case, Seven Cty. Infrastructure Coal. v. Eagle Cty., 145 S. Ct. 1497, 1507 (2025), seven Utah counties wanted to build an 88-mile railroad in the Uinta Basin. The agency in charge, the U.S. Surface Transportation Board, put together a huge 3,600-page EIS. It looked at everything from wildlife to air quality. They also mentioned other possible mining and refining projects nearby, but since those were just ideas and not actual plans, they didn’t go into detail. 

A federal appeals court in D.C. said that wasn’t good enough they wanted a deeper dive into all those “what if” future projects. But the Supreme Court stepped in and said: hold on. NEPA doesn’t require agencies to analyze every hypothetical project that might someday exist. They just need to focus on the project they’re actually reviewing and its reasonably foreseeable effects. 

As a result, it’s harder for opponents to argue that an EIS is incomplete. A challenger will need to prove that the EIS didn’t include reasonably foreseeable effects. This bar is incredibly high as the Court emphasized; the agency gets a fair amount of discretion in constructing its EIS, and its length or level of detail are up to the Agency’s discretion. 

This ruling sheds light on an area where Loper Bright’s power shift does not reach. In Loper Bright, the Supreme Court said judges, not agencies, get the final say on how federal laws are interpreted. That means courts can now take a closer look at the legal framework behind an agency’s decisions. But here, the Court still made it clear: when it comes to the nitty-gritty details of something like an EIS, agencies get a lot of discretion. In other words, Loper Bright may have shifted power toward judges on what powers a statute grants, but where the statute is clear as to what it requires of an agency, the technical contents are still up to the agency experts. Even if that deference allows agencies to severely limit the allowable scope of impacts under NEPA review, as they did in Seven County. 

But like the definition of “waters of the United States” post-Sackett, NEPA is also being eroded by Presidential and executive agency actions. Earlier in 2025, the Council for Environmental Quality, the agency tasked with implementing NEPA, revoked its NEPA regulations, allowing agencies to rescind and weaken their own NEPA regulations, including by replacing regulations with non-binding guidance. And just like the protection of our nation’s wetlands, environmental impact review is now going to fall under the states, many of which do not have the laws set up to allow for this kind of review.  

PennFuture’s attorneys are working hard to protect our environment and the rule of law. Support our efforts by donating to our Legal Environmental Advocacy Fund (LEAF) today!