A unanimous Supreme Court is making it easier for property owners to get their day in court against the federal government, with three justices additionally suggesting that some government claims of power over private property may violate the Constitution.

In an opinion written by Chief Justice John Roberts, the Supreme Court ruled 8-0 in Army Corps of Engineers v. Hawkes Co. that a landowner can sue an agency over its “approved” version of a “Jurisdictional Determination.”

A mining operation, Hawkes Company, wanted to challenge an approved JD declaring that company property was a federally protected wetland, restricting its ability to use the land. When the company attempted to challenge the JD in court, the Obama administration claimed that a person cannot sue over a JD, arguing that it is not a “final agency action” that can be taken to court under the Administrative Procedure Act (APA).

Currently, property owners can get a JD from the Army Corps of Engineers to ensure that planned land uses or construction projects do not violate the Clean Water Act (CWA), a federal law administered by the Environmental Protection Agency (EPA). Like the Corps, the EPA abides by the results of a JD.

Aspects of the CWA have long rankled constitutional conservatives, because the Constitution gives no direct authority to the federal government to regulate the environment. Under the Tenth Amendment, this is primarily the responsibility of the 50 sovereign states.

Congress therefore often justifies this type of regulatory environmental authority as part of its power to regulate interstate commerce.

But there are limits to federal power under the Commerce Clause. To stay within those limits, the CWA claims to apply only to the “waters of the United States,” which federal law defines as “navigable waters” that can be used in “interstate commerce.”

Although no one joined him, Justice Anthony Kennedy wrote the controlling opinion for Supreme Court in the 2006 case Rapanos v. United States, writing that the CWA extended to all waters that have a “significant nexus” to navigable waters, a rule sharply criticized by conservatives and difficult to define in practice.

In this case, the federal government said the waters Hawkes Company wanted to use have a significant nexus to the Red River—which is fully 120 miles away—and that therefore the Corps’ permission was necessary before the company could extract peat from the land.

In an aside, Roberts added some levity to his opinion by noting that the peat was of such “high quality” that it was “suitable for use in golf greens,” resulting in “smooth, stable greens that leave golfers with no one to blame but themselves for errant puts.”

Roberts wrote for the Court that an approved JD is a final agency action that can be immediately reviewed in a lawsuit by a federal district court because it “marks the consummation of the Corps’ decisionmaking process,” and because it “gives rise to direct and appreciable legal consequences.”

If an approved JD claims that the land in question is protected by the CWA, the property owner would be subject to $37,500 per day in potential penalties for violating the CWA if he then uses the land. On the other hand, if the JD says the land is not a protected wetland, that determination is good for five years, during which time the owner can use the land without fear of the federal government coming after him.

Justices Ruth Bader Ginsburg and Elena Kagan wrote dueling concurring opinions, disagreeing with each other on the significance of the memorandum between the Army Corps of Engineers and the EPA, whereby the EPA agrees to adhere to the Corps’s JD.

Kennedy joined Roberts’s opinion, but also wrote a separate concurring opinion, joined by conservative Justices Clarence Thomas and Samuel Alito, raising points that could signal a major change in the law in coming years.

Kennedy wrote that “the reach and systemic consequences for the Clean Water Act remain a cause for concern.” He quoted a 2012 case, Sackett v. EPA, Alito called the CWA “notoriously unclear.” In Hawkes Co., Kennedy agreed with that assessment, adding that “the consequences to landowners even for inadvertent violations can be crushing.”

But Kennedy and the conservative justices also noted with alarm that the Obama administration’s lawyers had argued in this case that while the EPA currently abides by the Corps’s JD, the EPA is not legally bound to do so. Moreover, the EPA claims it can revoke or amend the JD whenever it wants. “If that were correct, the Act’s ominous reach would again be unchecked by the limited relief the Court allows today,” he reasoned.

Kennedy then put a shot across the bow of the EPA, warning that if the EPA ever tried to assert such power, “it will have a significant bearing on whether the Clean Water Act comports with due process,” and thus that the Supreme Court could hold it was unconstitutional.

Kennedy concluded, “The Act, especially without the JD procedure were the Government permitted to foreclose it, continues to raise troubling questions regarding the Government’s power to cast doubt on the full use and enjoyment of private property throughout the Nation.”

It is not clear from this decision whether Roberts shares the concerns expressed by Kennedy, Thomas, and Alito, and thus whether a Donald Trump presidential victory in November could tip the balance if another conservative justice is added to the Supreme Court.

Ken Klukowski is legal editor for Breitbart News. Follow him on Twitter @kenklukowski.