Jack and Jill Barron erected these signs in protest of an Environmental Protection Agency determination that wetlands exist on their property at Priest Lake in Idaho. (Keith Kinnaird/AP)

The Supreme Court on Wednesday unanimously ruled for an Idaho couple who have been in a four-year battle with the Environmental Protection Agency over the government’s claim that the land on which they plan to build a home contains sensitive wetlands.

The decision allows Mike and Chantell Sackett to go to court to challenge the agency’s order. More broadly, it gives landowners and businesses a tool to fight the approximately 1,500 administrative compliance orders that the EPA issues each year to try to force an immediate halt to what the agency considers environmental damage.

The government had taken the position that such orders were not open to judicial review until the agency took final action.

But the court disagreed.

“There is no reason to think that the Clean Water Act was uniquely designed to enable the strong-arming of regulated parties into ‘voluntary compliance’ without the opportunity for review — even judicial review of the question [of] whether the regulated party is within the EPA’s jurisdiction,” Justice Antonin Scalia wrote.

The decision, although narrow, was seen as a victory for developers, corporations, utilities, libertarians and others who have said the EPA’s actions were an abuse of power.

“The justices have made it clear that EPA bureaucrats are answerable to the law and the courts, just like the rest of us,” said Damien M. Schiff of the Pacific Legal Foundation, which represented the Sacketts. “EPA can’t try to micromanage people and their property — it can’t order property owners to dance like marionettes — while denying them any meaningful right to appeal to the courts.”

Environmentalists took the view that the ruling was narrow and did not contest the EPA’s ability to issue compliance orders. “The court did not adopt any of the radical ideas advanced by industry and its allies that could have severely hampered public health and environmental protections,” said Jon Devine, a senior attorney for the Natural Resources Defense Council.

The Sacketts want to build a home on a 0.63-acre lot that they bought for $23,000 near pristine Priest Lake in the Idaho panhandle. But after three days in which the couple brought in fill dirt and prepared for construction in 2007, officials from the EPA and the U.S. Army Corps of Engineers ordered the activity stopped and said they suspected that the land contained wetlands.

Months later, the agency sent the Sacketts a compliance order that said the lot must be restored as wetlands before the couple could apply for a building permit. The government acknowledged that fines for failure to comply with the order could be as much as $75,000 a day.

The question for the justices was whether the couple had a right at that point to appear before a judge and contest the agency’s contention that their land contained wetlands subject to the Clean Water Act.

Scalia joked in summarizing the decision from the bench that the Sacketts were surprised by the EPA’s decision that their land contained “waters of the United States,” since they had “never seen a ship or other vessel cross their yard.”

Lower courts agreed with the government that the agency’s compliance orders are not subject to judicial review. They said that because the EPA must prove a violation to a judge for the court to levy fines, that is the proper time for the courts to get involved.

The government has said that the EPA’s power to issue compliance orders, with their threats of huge fines, is a way to quickly move to stop environmental damage and that allowing polluters to go to court would tie up the agency in litigation.

The court’s opinion said that power could still be used. “Compliance orders will remain an effective means of securing prompt voluntary compliance in those many cases where there is no substantial basis to question their validity,” Scalia wrote.

Even though the decision means only that the Sacketts may go to court to challenge the EPA’s jurisdiction over their property, Mike Sackett said he felt like “the Supreme Court came to our rescue.”

The court’s narrow decision comes as the White House is weighing whether to issue a slew of environmental regulations before the fall election. Some critics say they believe that the EPA will no longer push the limits of its authority.

Ashley Lyon McDonald, deputy environmental counsel for the National Cattlemen’s Beef Association, called the ruling “a win for private property owners” that should serve as a cautionary lesson for EPA officials.

She added, however, that her group and others were hoping that the court would define precisely what constitutes a wetland, a definition that has been muddied by Supreme Court decisions in 2001 and 2006.

Justice Samuel A. Alito Jr., in a concurring opinion, said such definitions are needed.

“The reach of the Clean Water Act is notoriously unclear,” Alito wrote. “Any piece of land that is wet at least part of the year is in danger of being classified by EPA employees as wetlands covered by the act, and according to the federal government, if property owners begin to construct a home on a lot that the agency thinks possesses the requisite wetness, the property owners are at the agency’s mercy.”

The EPA has drafted wetlands guidance and last month sent the proposal to the Office of Management and Budget. That proposal would limit the amount of pollution that could be put into wetlands and streams.

Jan Goldman-Carter, senior manager for wetlands and water resources at the National Wildlife Federation, an advocacy group, said she remains confident that the administration will finalize new wetlands rules this year.

“They see the need to clarify this guidance,” she said.

The case is Sackett v. EPA.