JUNEAU (AP) -- A mining company wants to double its tailings facility on Admiralty Island -- already one of the largest tailings dumps in the country.
Kennecott Greens Creek Mining Co. says its existing 40-acre tailings dump is not large enough for the 4 million tons of potentially toxic rock the company expects to dispose over the next 14 years.
The company wants to expand the tailings dump 84.5 acres to the west and southwest, and is applying for a permit.
Eric Ouderkirk, Greens Creek project manager for the U.S. Forest Service, said the company essentially wants to enlarge the pile.
An Environmental Protection Agency report for 1999 listed Greens Creek as the second largest producer of toxic waste in the state and the 15th in the country.
''The Forest Service and the public need to take a hard look at the potential impacts of millions of additional pounds of toxic waste on Admiralty's fisheries, wildlife and water quality,'' said Sarah Keeney, water quality and mining organizer for the Southeast Alaska Conservation Council.
The greatest concern is how to protect Admiralty National Monument and adjacent waters from acid runoff that comes out of the piles of ground waste rock.
The tailings contain naturally occurring sulfides, including pyrite or fools gold, which react with air and water to create an acid runoff. Acid runoff kills vegetation, and can hurt fish and other species.
The concern about acid runoff is not new to Greens Creek operators, said Bill Oelklaus, environmental manager at Greens Creek.
''Our designs and our work have always been focused toward protecting from those problems,'' Oelklaus said.
The presence of natural acid runoff led to the initial discovery of the mine site in the 1970s. A geologist flying over Admiralty Island noticed large bare patches in the forest, said Brad Flynn, Forest Service supervisory resource assistant for Admiralty National Monument.
Sulfides leaching to the surface were causing acid runoff to kill the surrounding plant life, a sign that zinc and silver might also be found there.
''You'll go out and see a little space where the grass isn't growing or you'll get a funny color and that's from the acid being produced,'' Flynn said.
Because of the potential for toxic runoff, mines must report all the rock they pull out and move around as toxic releases. About 70 percent of the material pulled from Greens Creek mine ends up as tailings and waste rock.
Camille Stephens at the state Department of Environmental Conservation, said the releases are being contained.
Half the Greens Creek tailings and waste rock go back into the mine to fill in old tunnels. The rest is trucked to the tailings disposal site.
The site was initially selected in 1983 because it is relatively flat, big enough for the tailings and would create the least environmental impact, Oelklaus said. The dumpsite also has a layer of clay two to 25 feet thick that creates a natural barrier below the tailings piles.
The public is invited to comment on the permit application at a meeting at 7 p.m. Thursday in the assembly chambers at City Hall.
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