A proposed copper and gold mine in Alaska could impact up to 12,000 acres of wetlands as well as local fisheries but would help meet a worldwide demand for copper, according to the draft environmental impact statement on the Pebble Mine in the Bristol Bay area of Alaska.

The 1,400-page DEIS released by the Army Corps of Engineers on Feb. 20 reaches no conclusions about the project, but in a statement, Pebble Mine developer, Northern Dynasty Minerals and its subsidiary, Pebble Limited Partnership, says the DEIS shows no “significant environmental challenges that would preclude the project from getting a permit.”

The Corps expects to release a final EIS in early 2020 following a public comment period from March 1 to May 31 this year. A record of decision would be issued in mid-2020.

 The United Tribes of Bristol Bay says the DEIS was flawed and inadequate. “The Draft EIS is further evidence that the process is rigged in Pebble’s favor,” said Alannah Hurley, executive director of the United Tribes, in a statement. “The Army Corps’ review ignores the very real concerns about the changes and devastation Pebble would bring to our region, and is clearly the result of a rushed process that has ignored local voices and ignores the existing science.” NRDC says that the Corps document is “a superficial review of the largest ever proposed mine in Alaska.”

The Alaska Corps office, responsible for producing the DEIS, didn’t immediately respond to a request for comment.

Last year, then-EPA Administrator Scott Pruitt said Northern Dynasty’s application could move forward, but that environmental restrictions put in place by the Obama administration would remain in place. At the time, Pruitt said mining would likely pose a risk and that the permit application, “must clear a high bar.”

According to the DEIS, the project, 200 miles southwest of Anchorage and 60 miles west of Cook inlet, would consist of an open pit mine and associated infrastructure, including a 270-MW power plant, on about 8,000 acres, and a 188-mile natural gas pipeline. The site could have a port at Amakdedori, an alternative that would have the greatest impact on wetlands and the estuary. Wetlands represent about 39% of the site. All alternatives studied would affect more than 3,500 acres of wetlands.

Construction of the mine would take about four years and require 2,000 workers at peak.

The DEIS found that the project would destroy 4% of spawning area for Coho salmon in Bristol Bay. One alternative, to construct a deepwater port, would affect the chum and pink salmon fishery and could affect the recovery of the Pacific herring fishery.