The Army Corps of Engineers on Wednesday denied a permit for the proposed Pebble Mine in Alaska, likely dealing a death blow to the long-disputed project.

In a statement, the Corps said it “determined that the applicant’s plan for the discharge of fill material does not comply with Clean Water Act guidelines and concluded that the proposed project is contrary to the public interest.”

The decision, the agency said, “reflects a regulatory process that is fair, flexible and balanced.”

The decision on the proposed gold and copper mine in a remote part of Southwest Alaska is a victory for Native groups, environmentalists, the state’s fishing industry and others who opposed the project.

Opponents said the large open-pit operation, which would dig up and process tens of millions of tons of rock a year, would irreversibly harm breeding grounds for salmon that are the basis for a sports-fishing industry and a large commercial fishery in nearby Bristol Bay. Salmon are also a major subsistence food of Alaska Natives in the region.

“The Corps’ denial of the permit for the Pebble Mine is a victory for common sense,” said Chris Wood, CEO of the conservation group Trout Unlimited. “Bristol Bay is the wrong place for industrial scale mining.”


Spokesmen for the mine’s developers, Pebble Limited Partnership and its parent, Northern Dynasty Minerals, did not immediately respond to requests for comment.

In July, the Corps, which had authority to approve a permit under the federal Clean Water Act, approved an environmental-impact statement on the project that said it would not permanently harm the fishing industry. But a few weeks later, the Corps said that the company’s plan to compensate for environmental damage from the mine was insufficient, and requested a new mitigation plan.

The new plan, which was not publicly released but was believed to designate land near the mine to be permanently protected, was submitted last week.

The fight over the fate of what is one of the largest deposits of copper and gold ore in the world has raged for more than a decade. The mining industry and many state officials have supported the project for the revenue and other economic benefits it would bring. But some important Alaskan politicians, notably Sen. Lisa Murkowski, a Republican, have been noncommittal, saying the mine should go forward only if it could be shown to be environmentally sound.

The project was effectively scuttled by the Obama administration, only to be revived by the Trump White House. Under the Trump administration, the Environmental Protection Agency reversed an earlier ruling, allowing the environmental review by the Corps to proceed.

But support among Republicans was never as ironclad as it has been for some other projects with potential environmental consequences, notably potential oil and gas drilling in the Arctic National Wildlife Refuge, also in Alaska.


The Pebble project even generated a rare dispute within the Trump family. In August, Donald Trump Jr., an avid sportsman who has fished in the Bristol Bay area, tweeted his opposition to the mine: “The headwaters of Bristol Bay and the surrounding fishery are too unique and fragile to take any chances with. #PebbleMine.”

President Donald Trump, when asked in the following days about his son’s sentiments and the prospects for the project, said only that he would “look at both sides” of the issue and that politics would not play a role in any decision. Privately, however, administration officials said they expected that the permit would be approved.

But in September, the future of the multibillion dollar project appeared in doubt when secret recordings of company executives suggested that they were planning for a much larger mine, and one that would operate far longer, than what had been proposed to the Corps.

The recordings were obtained by an environmental advocacy group, with two members who were posing as potential investors in the project meeting by video with two project executives. The executives described how the mine could operate for 160 years or more beyond the proposed 20 years, and how its output could double after the first two decades.

In the fallout from the recordings, one of the executives, Tom Collier, CEO of the Pebble Partnership, resigned.