Anglo American, one of the world's biggest mining corporations, wants Alaska's permission to build a massive gold and copper mine in the headwaters of the top salmon-producing rivers in the Bristol Bay region. As a scientist who has studied mining for more than 25 years, I believe the threats posed by Pebble loom larger than any mine developed in the last 30 years in the United States.
While Anglo American has promised the Pebble mine won't harm Bristol Bay's rich salmon fishery, it is best to judge this promise in light of the impacts that other Anglo American mines have had on clean water and clean air.
From a Nevada perspective, Anglo American's record is not good.
For years, the largest single source of mercury air pollution in the United States was the Jerritt Canyon gold mine in northern Nevada, which Anglo American owned through a subsidiary.
Between 1998 -- the first year EPA required reporting mines like Jerritt Canyon -- and 2001, the mine emitted between 4,700 to more than 9,000 pounds of mercury into the air each year, or about 25 to more than 50 times as much as a single medium-sized coal-fired power plant produces annually.
Worse yet, Jerritt Canyon's tailings pond, which holds millions of tons of cyanide-processed ore, has leaked ever since it was built in the mid-1980s. According to Nevada Division of Environmental Protection records, this contaminated slurry of waste that contains mercury and arsenic has been leaking into groundwater for years, some of which has gotten past the extensive pump-back system.
The very large waste rock dumps at Jerritt Canyon, as well as Anglo's closed Big Springs Mine, are both releasing large quantities of sulfate and other contaminants into surface water, with no end in sight to this contamination. The releases exceed discharge standards for surface water, but Anglo has never been compelled to clean up these sources. They sold this problem to the next owner, Queenstake, but the problems created under Anglo's stewardship remain. Queenstake has now been purchased by another company, Yukon-Nevada Gold Corp., which apparently has run into financial problems. It has recently shut down the Jerritt Canyon mine and most of the employees are gone. While the site does have a closure bond, the problems at the site, particularly the tailings facility and mercury issues, have not been addressed in a systematic manner. Without a clear plan on closure, nobody can ensure that the bond is sufficient to truly remediate the site.
Where is the expertise in mine closure and the management and technical skills of Anglo? The state and federal agencies now are dealing with a small company that is in apparently financially difficult times attempting to re-start the mill, and at the same time deal with severe environmental challenges, most of which began during Anglo American's ownership.
State and federal agencies repeatedly expressed concerns about pollution from Jerritt Canyon during Anglo American's tenure. Yet the corporation failed to fix what has become an extensive and serious water pollution problem that will persist for many generations to come.
Anglo American's resistance to fixing water pollution problems, and the fact that it allowed them to continue for so long, does not bode well for Alaska.
Pebble is different of course, but in ways that could actually magnify problems.
Pebble would be a much bigger mine than Jerritt Canyon. Pebble would unearth billions of tons of the type of sulfur-bearing rock that creates acid drainage. But unlike Jerritt Canyon, there's not much limestone buffer, which means acid drainage is likely. Copper, zinc and other heavy metals are also likely to get into surface water during operations. Over time, this pollution would threaten wild salmon and the Alaskans who depend on them to sustain their jobs and traditions.
If Anglo American's past performance is any indication, Alaskans should be wary. At Jerritt Canyon, a modern mine operating under well-established environmental laws, Anglo American's assurances that it would maintain high environmental standards clearly were not met.
Alaskans will make up their own minds about Pebble, but they deserve to know the previous record of Anglo American, not just what its consultants want them to know.
Glenn Miller is a professor of natural resources and environmental sciences at the University of Nevada, Reno and is on the board of directors of Earthworks and the Center for Science in Public Participation.