Environmentalists trying to stop a controversial copper-nickel mine near the Boundary Waters Canoe Area Wilderness in northern Minnesota won a partial victory in a massive federal spending bill that includes a provision for a new study of potential water pollution from the project.

The measure, pushed by Minnesota U.S. Rep. Betty McCollum, includes language that gives the State Department 60 days to “report to Congress on the effects of sulfide-ore copper mining in the Superior National Forest on international waters shared with Canada and protected by the 1909 Boundary Waters treaty.”

That treaty includes an article that reads, “It is further agreed that the waters herein defined as boundary waters and waters flowing across the boundary shall not be polluted on either side to the injury of health or property on the other.”

Though the measure was reportedly opposed by the White House, McCollum said it was included in a $1.4 trillion federal budget agreement signed Friday by President Donald Trump. Environmentalists praised the new State Department review as a tool to potentially slow down or halt the project altogether.

Early in Trump’s term his administration renewed mining leases for Twin Metals Minnesota, canceling a U.S. Forest Service study of hard-rock mining in Superior National Forest that had been initiated by the Obama administration. The mining company, a subsidiary of Chilean-based Antofagasta, is planning a copper-nickel mine southeast of Ely; advocates of the BWCA see that wreaking havoc on a state treasure.

McCollum, the Democratic chairwoman of a House Appropriations subcommittee that manages federal natural resources, had sought to revive the Forest Service study through the federal budget process. Her chief of staff, Bill Harper, said in an interview that the Trump administration flatly refused in the final hours of budget talks.

“It was in there until the very end, and it was the absolute insistence of the White House that it be removed,” Harper said.

McCollum, however, also had included the language related to Canadian waters. The government of Canada has publicly expressed concerns about the impact of the Twin Metals projects on Canadian waters in the adjoining Quetico Provincial Park.

The White House also demanded the removal of the State Department study from the final budget bill, Harper said. But when the massive document was printed, he said, the provision was still in there. His best guess is it was some kind of oversight. Trump signed the bill anyway, providing McCollum a budget victory.

“These pristine waters belong to all of us, and it’s important we all do our part to keep them intact,” McCollum said in a news release. She said she sent letters to Secretary of State Mike Pompeo and Canadian Prime Minister Justin Trudeau apprising them of the expected report by the State Department.

A White House spokeswoman did not respond to a request for comment Monday.

In a statement, Twin Metals said: “We are confident that we can advance a project that will bring significant economic development to northeast Minnesota while also meeting or exceeding all regulatory requirements.”

Becky Rom, national chairwoman of the Campaign to Save the Boundary Waters, said she hoped that McCollum’s maneuver would give advocates a way to pry loose data that was collected as part of the aborted Forest Service study.

She said it “seems reasonable to assume that the State Department would consult with the Forest Service about the detailed study it has already almost entirely conducted about the environmental, economic and social harm of mining in the watershed.”

The political fight over the Twin Metals proposal has divided members of Minnesota’s congressional delegation. While McCollum has fought to strengthen regulatory oversight of the project, Republican Reps. Tom Emmer and Pete Stauber have pushed for faster approval, arguing that it will spur job growth and benefit the region’s economy.

“Efforts to create new and disingenuous redundancies to the already stringent environmental review processes will do nothing but undermine the livelihoods of thousands of hardworking Minnesotans,” Emmer said Monday.

Stauber, whose district includes the mine site, praised Twin Metals’ recently released plan, saying, “In northern Minnesota, mining is our past, present and future.”

Last week, the House approved the federal budget deal with votes from both Democratic and Republican lawmakers. Stauber voted for the agreement, while Emmer voted against it.