ANCHORAGE, Alaska -- The Trump administration Friday issued a final environmental review of the proposed Pebble copper and gold mine in southwest Alaska that will smooth the path for the mine's eventual development.
The U.S. Army Corps of Engineers report found that the mine should not hurt the long-term health of the valuable Bristol Bay salmon fishery, or significantly affect salmon returns, a conclusion that tribal, fishing and conservation groups swiftly condemned.
Under normal operations, the Corps wrote, the project would not result in "long-term changes in the health of the commercial fisheries in Bristol Bay."
The review contradicts a 2014 report by the administration of President Barack Obama that found the mine would severely damage the Bristol Bay watershed.
Mine developer Pebble Limited Partnership praised the analysis as a milestone that sets the stage for the project's development.
"I think this is the single most significant day in the history of the Pebble project," said Tom Collier, chief executive of Pebble Limited, on Friday. "On the issue of fish, it unequivocally and repeatedly says there will be no significant damage."
The open-pit mine would be built near the headwaters of salmon-producing rivers that support the Bristol Bay fishery, about 200 miles southwest of Anchorage. Major facilities would include a gas pipeline across Cook Inlet, a port site at the inlet, an 80-mile road to the mine site, and a 270-megawatt power plant.
The mining pit would cover a square mile and be a third of a mile deep, said Mike Heatwole, a spokesman for Pebble.
The company has said the prospect could become one of the largest copper and gold mines in the U.S., annually producing 318 million pounds of copper and 362,000 ounces of gold for 20 years.
The environmental analysis allows the Corps, after at least 30 days, to issue a permit needed to build the mine under the Clean Water Act, allowing damage to wetlands and streams in the area. The Corps could also reject Pebble's application, or issue a permit with modifications.
Approval of that permit, and two others from the U.S. Coast Guard and the Bureau of Safety and Environmental Enforcement, would conclude the federal permitting process and launch a three-year state permitting process, Pebble has said.
The analysis "is not the thorough, science-based assessment that we were promised," Frances Leach, executive director of United Fishermen for Alaska, said in a news release.
The Corps has not fully addressed numerous issues raised during the public review process that led to the report, said Nelli Williams with Trout Unlimited Alaska.
"They have that wrong," Williams said.
The report shows the mine would damage more than 191 miles of streams and 4,614 acres of wetlands, she said. In most cases, the damage would be permanent, she said.
Information for this article was contributed by Alex Demarban of the Anchorage Daily News and by Henry Fountain of The New York Times.