WASHINGTON – The Environmental Protection Agency on Monday moved to ensure it has a role negotiating the terms of any permit for the massive Pebble Mine planned near Alaska’s Bristol Bay, a move that may bolster the permit’s chances of approval.

The EPA’s action comes as the US Army Corps of Engineers evaluates how the proposed gold, copper and molybdenum mine would affect the region’s water, land and thriving salmon fishery. In comments filed with the Army Corps, the EPA invoked a provision in a federal clean-water law that would allow top officials from both agencies to work out disagreements over a potential mine permit.

The EPA last week decided to resume consideration of proposed water pollution restrictions that threatened the project since the Obama administration outlined the restrictions in 2014.

The EPA’s continued involvement could be welcomed by supporters of the mine, developer Pebble and its parent company, Northern Dynasty Minerals.

However, the EPA stressed that its action should not be viewed as a decision on the project or what to do about those five-year-old proposed restrictions. Regional EPA officials are coordinating with the Army Corps “to ensure that the EPA can continue to work with the Corps to address concerns raised during the permitting process,” the agency said in letters and formal comments made public Tuesday.

Under another administration, the EPA’s intervention might signal the agency’s desire to prod the Army Corps into rejecting a permit, said Taryn Kiekow Heimer, a senior advocate at the Natural Resources Defense Council. Now that President Donald Trump’s EPA is reconsidering the 2014 restrictions, the opposite outcome is possible, she said.

The EPA told the Army Corps it believed the proposed mine poses a “substantial and unacceptable” impact on an “aquatic resource of national importance” -- a legal threshold for the agency’s continued involvement.

The EPA also criticized the Army Corps’ draft environmental impact statement on the project, saying it “appears to lack certain critical information about the proposed project” and “likely underestimates impacts and risks.” The EPA said it had “concerns regarding the extent and magnitude of the substantial proposed impacts to streams, wetlands and other aquatic resources that may result” from the project.

Project critics have said the Army Corps’ analysis takes a narrow view of its potential impacts, failing to consider the collective damage from potential leaks and spills at the site.

“The Pebble Mine project is the largest, most complex and riskiest resource project proposed in Alaska,” said McKie Campbell, a former deputy commissioner of the state’s Department of Fish and Game. “In spite of this, it is being evaluated with the most flawed and rushed environmental impact statement that I have ever been aware of.”

EPA General Counsel Matthew Leopold previously said the consultation procedure was needed “to align the EPA with the Army Corps process to ensure all potential significant impacts to the environment are thoroughly vetted and raised before any final decision on the permit can be reached.”

Developers, who have spent millions lobbying on behalf of the project, say the mine would tap a massive gold and copper resource. But the project is located in an area that drains into Bristol Bay, home to the world’s most productive wild salmon fishery, raising concerns about its potential environmental cost.

Conservationists, local activists and fishing operations warned the Army Corps the mine could jeopardize the region’s salmon and a flourishing fishery with a catch that topped $281-million last year.