MINNEAPOLIS (AP) — One day after Gov. Mark Dayton dealt a serious blow to a proposed copper-nickel-precious metals mine near the Boundary Waters Canoe Area Wilderness, a federal agency handed the company another setback Tuesday by concluding that it’s not automatically entitled to renew two important minerals leases.

Twin Metals Minnesota wants to build a $2.8 billion underground mine southeast of Ely near Birch Lake that the company says would create about 850 full-time jobs. Environmentalists oppose it because the site sits within a watershed that flows into Boundary Waters, one of the country’s most popular wilderness areas. Dayton cited that proximity in a letter to the company Monday, saying the state won’t authorize access to its lands for the project.

Twin Metals officials declined Tuesday to comment on how significant a setback Dayton’s decision was, but issued a statement saying they’re reviewing the new opinion on the leases from the U.S. Department of the Interior.

One of critics’ chief objections to mining the large reserves of copper, nickel and precious metals in northeastern Minnesota are that the metals are bound up in sulfide compounds that can leach sulfuric acid and heavy metals if exposed to air and water. Opponents say acid mine runoff would cause irreparable damage if it flows into the wilderness area.

The Interior Department’s solicitor, Hilary Tompkins, told the BLM’s director, Neil Kornze, in a memo Tuesday that Twin Metals does not have an automatic right of renewal to the leases and that the bureau has discretion to grant or deny the application. The leases have expired; they were first issued in 1966 and last renewed in 2004.

Becky Rom, national chair for the Campaign to Save the Boundary Waters, welcomed the solicitor’s conclusion, saying the agencies involved are now legally obligated to conduct a rigorous environmental review before deciding whether to renew the leases, which wasn’t required before.

“The common-sense legal decision that the Bureau of Land Management can say ‘no’ to renewing the federal mineral leases is an important step forward for Minnesotans and millions of Americans who want to protect this national treasure,” Rom said in a statement.

In his letter, Dayton said he called Kornze last week to tell him of his “strong opposition” to mining so close to the Boundary Waters. He said he was informed that the BLM was considering whether to renew the federal leases.

“I believe that the BLM decision will offer further guidance on the future of mining in the area,” Dayton wrote.

Frank Ongaro, executive director of the trade group Mining Minnesota, called Dayton’s decision “very concerning,” saying it could have “serious consequences” for other companies besides Twin Metals, which is owned by Chilean mining giant Antofagasta PLC. He also questioned whether the governor’s decision was legal, given that state law directs that some of the affected state-owned lands be managed to produce revenue for a school trust fund.

Dayton announced his decision just four days after the DNR approved the final environmental review for a different copper-nickel mine proposal. The PolyMet mine would sit several miles to the west of Twin Metals, in a different watershed that ultimately flows into Lake Superior. PolyMet will soon start applying for permits, which is expected to be a contentious process.

Twin Metals would be a much bigger mine but isn’t nearly as far along. Company officials previously said they were still developing a mine plan and hoped to submit it to regulators to begin the environmental review process in 2018.

(© Copyright 2016 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)