On Thursday, the US Supreme Court issued a ruling that severely limits the Environmental Protection Agency's ability to regulate pollution under the Clean Water Act. The ruling applies to wetlands that are connected to bodies of water that fall under the Clean Water Act's regulatory scheme, with the court now ruling that those connections need to be direct and contiguous for the act to apply. This would remove many wetlands separated by small strips of land—including artificial structures like levees—from oversight by the EPA.
The decision is a somewhat unusual one in that all nine justices agree that the people who originally sued the EPA should prevail. But there was a very sharply worded 5-4 disagreement over what the word "adjacent" means.
Whose waters are these?
The Clean Water Act was a major piece of environmental regulation due to the sometimes horrific pollution prevalent in the early 1970s. Its text applies regulations to the "waters of the United States," a term that has proven sufficiently vague that it has been the subject of various lawsuits and federal regulatory policies over the years. Several geographic features—seasonal streams, human-made water features, and marshlands without a direct connection to rivers—have all been subject to dispute.
Even the Supreme Court found the issue difficult. In one of the more relevant cases, the court had a 4-4-1 split regarding the issue of whether wetlands without a direct connection to open waters were subject to regulation. Anthony Kennedy, who was the party of one, determined that there had to be a "significant nexus" connecting the two, a phrase that was also a subject of continual debate.
Against that backdrop, the relevant federal agencies (the EPA and Army Corps of Engineers) have pursued rulemaking under different interpretations of "significant nexus," with more expansive ones prevailing under Democratic presidencies. The Trump administration's attempt to limit the scope of regulations was thrown out by a court in 2021. The Biden administration's replacement only took effect this year.
Brewing in the background since 2007 was a case called Sackett v. EPA. The Sacketts owned property near an Idaho lake and filled in some wetlands to build a house on the property. The EPA, noting that the wetlands drained into the lake via a nearby ditch, ordered the couple to restore the property to its original condition. The Sacketts sued, leading to the case that was before the Supreme Court.
Logic games
The entire court agrees that the connection between the Sacketts' property and the lake is too tenuous for it to fall under the "waters of the US" category, so the EPA has no regulatory authority. But a five-Justice majority used the case as an opportunity to throw out the "significant nexus" standard and craft a rule that severely limits the wetlands that can be regulated by the EPA—to the point where it's now more restrictive than even the Trump administration had planned. Under the new ruling, the Clean Water Act only applies to wetlands that are contiguous with open water, where it's difficult to determine where the wetland ends and the river or lake begins.
To do so, the majority had to struggle with the text of the law, which explicitly covers "adjacent" wetlands. In the ruling, this was done by noting that "adjacent" could have multiple definitions and identifying other areas of the Clean Water Act that, when combined, provided a more stringent definition of "adjacent." In practice, this looked a lot like playing a logic game, with the ruling literally defining the relevant wetlands using the phrase “A minus B, which includes C.”
The majority also dismisses a later amendment to the Clean Water Act that seemingly uses a more expansive definition of adjacent as "a relatively obscure provision."
Justices Thomas and Gorsuch, while concurring with these limitations, argue that the court isn't going far enough because it isn't completely crippling the Clean Water Act's scope. Making reference to colonial-era English common law and the Steamboat Act of 1838, they argue that Congress only has constitutional authority over bodies of water that can be used for trade. In this view, most of the water in the US doesn't count.
As Thomas and Gorsuch note, this view would exclude congressional authority over interstate commerce like the sale of fish or recreation by out-of-state residents. That has been well outside the judicial mainstream since around the time of the New Deal. But an originalist can dream, I guess.
Lots of dissenting
The primary focus of the dissent is from Justice Kavanaugh, with whom the court's three liberal justices concur. He's perfectly comfortable with rejecting the use of the vague "significant nexus" as the determining factor. But he also recognizes that the Clean Water Act says "adjacent" wetlands, and the new ruling specifies what he'd define as adjoining ones. "In my view, the Court’s 'continuous surface connection' test departs from the statutory text, from 45 years of consistent agency practice, and from this Court’s precedents," Kavanaugh argues.
He calls the majority's logic game—"A minus B, which includes C"—"A fancier way of arguing (against all indications of ordinary meaning) that 'adjacent' means 'adjoining.'" He notes that other portions of the act actually do use "adjoining," indicating that Congress could have specified this if it was what it meant. And he notes that Congress considered limiting the statute's scope when amending it in 1977, and specifically chose not to.
Kavanaugh also notes that the ruling is going to have consequences that are problematic. "The Mississippi River features an extensive levee system to prevent flooding," the dissent reads. "Under the Court’s 'continuous surface connection' test, the presence of those levees (the equivalent of a dike) would seemingly preclude Clean Water Act coverage of adjacent wetlands on the other side of the levees, even though the adjacent wetlands are often an important part of the flood-control project."
All of that is done with the regular use of "respectfully." In an additional dissent, the court's three liberal justices drop the respect and suggest that the majority is simply rewriting a law with implications it doesn't like. "The majority shelves the usual rules of interpretation—reading the text, determining what the words used there mean, and applying that ordinary understanding even if it conflicts with judges’ policy preferences."
It might get worse
This sort of ruling is largely in line with the current court's approach toward nearly all federal regulation, so it doesn't come as much of a surprise. But it's notable that the decision runs counter to the conclusions of an industry-heavy EPA scientific advisory board appointed by the Trump administration. The board noted that we've developed a much better understanding of how water moves into regulated waters through the ground and via temporary streams and that part of the EPA's remit involves using the best current scientific information in formulating its regulations.
The majority decision basically says that evolving with current scientific information is a bad thing. It cautions against relying on "a variety of open-ended factors that evolve as scientific understandings change," suggesting that it leads to little more than "a freewheeling inquiry." Past Supreme Court decisions have advised that courts should give deference to federal agencies that are staffed with experts in the subject matters at issue.
This approach has the potential to create tension when scientific evidence supports regulations that the current majority clearly finds distasteful. Portraying science as capricious could be how the current majority justifies ignoring scientific evidence.
