A report released last week by opponents to the proposed Pebble copper/gold project in southwest Alaska and aimed at financial investment groups claims significant legal and political risks will jeopardize the project.

But a spokesman for the companies that want to dig the mine discounted the report and says the project is still in its preliminary stages, too early for anyone to be drawing conclusions about its viability.

Earthworks, a Washington, D.C.-based conservation organization that does work on mining issues, authored the report. It was released Oct. 29 and was being distributing to investment groups in the United States and the United Kingdom, said Bonnie Gestring, the group's coordinator for the U.S. Northwest.

Pebble, owned equally by Anglo American and Northern Dynasty Minerals, is still in an advanced exploration stage with feasibility studies under way.

The Pebble deposit lies in southwest Alaska, about 200 miles southwest of Anchorage. It is one of the world's largest undeveloped copper and gold deposits, and also contains significant quantities of molybdenum, according to investor information on the project provided by Northern Dynasty.

A coalition of Alaska fishing and Alaska Native groups in the Bristol Bay region are hoping to halt the project, arguing that the mine poses risks to watersheds that support rich salmon spawning streams and one of the world's largest commercial salmon fisheries.

The report says that lawsuits and other obstacles will make it difficult for Anglo American and Northern Dynasty to obtain permits by 2012 and to have the mine in production by 2016, as its current timeline calls for.

"No other mining project in North America comes close to the scale, the complexity and the technological challenges that face the Pebble mine," said David Chambers, manager of the Center for Science and Public Participation in Montana, in a press release announcing the report.

Chambers and Stuart Levit, a mine reclamation specialist who works at the center, reviewed the Earthworks report.

"The risks identified in this report should be of particular interest to lenders," said Jonas Kron, an analyst with Trillium Asset Management Corp., in the press release. Trillium manages about $900 million in assets and leans toward socially responsible investment strategies, Gestring said.

Gestring said Earthworks paid for the report, which cost about $10,000, from its own membership and foundation funds.

In a statement, Anglo American discounted the report.

"This was prepared by individuals and groups well known for their opposition to the Pebble Project and it is disingenuous to describe it as an investor advisory," said Paul Henry, Anglo American's chief operating officer for Alaska.

"As is well understood, Pebble is still an exploration project and no mine development plan has yet been proposed," Henry said. "The assumptions and conclusions of the report are therefore premature and lack credibility."

Alaska state officials also said claims in the report are overstated. For example, an assertion that the mine would obtain water rights across a wide area is unfounded, said Ed Fogels, the state large mine permit manager in the Alaska Department of Natural Resources.

"Water rights? Where do they get that? We have to leave enough water for fish. We're not going to let a mining company dewater streams in the area," Fogels said.

Tim Bradner is a reporter for the Alaska Journal of Commerce.