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Kennecott Greens Creek Mining Co. wants to double its mine tailings facility, already one of the largest in the country.
The existing 40-acre tailings dump on Admiralty Island is not large enough for the 4 million tons of potentially toxic rock Greens Creek expects to dispose over the next 14 years. So the mine company is applying for a permit to expand the tailings dump 84.5 acres to the west and southwest.
"Essentially it's just enlarging the size of the pile," said Eric Ouderkirk, Greens Creek project manager for the U.S. Forest Service.
As the permitting process begins, the public is invited to bring up questions and concerns at a meeting at 7 p.m. Thursday in the assembly chambers at City Hall.
"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
"Acid mine drainage can plague an area for hundreds, if not thousands, of years after," Keeney said. "Once it starts, which they have found it has started out there, it's really hard to stop."
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. The area was nicknamed "The Big Sore."
"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. "It'll give kind of a rusting color sometimes."
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. In February that was 40,000 tons. 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 high ranking doesn't mean Greens Creek is doing anything wrong, since the releases are contained in a permitted facility, said Camille Stephens at the state Department of Environmental Conservation.
"It does make us look really bad and it's not just Alaska," Stephens said. "If you look at the other states, all the states that have the same kind of mining operations as Kennecott, they just jumped."
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.
Keeney questioned the reliance on the clay, suggesting a manmade liner would better protect the environment. But synthetic liners are more likely to slip or split, whereas the natural clay will last forever, Oelklaus said.
"We have a much better containment system than a synthetic liner would provide for us," Oelklaus said.
As tailings are added to the site, they are compacted to create a dense pile with little space for water or air to flow through. Eventually the tailings piles will be capped off, sealing them permanently.
Most of the tailings dump area is actually infrastructure set up to collect and treat water from the dump and mine site. The same will be true of the expanded site, where only 20 acres will be covered with tailings, Oelklaus said.
"Think of it as your house, with drainage pipes that collect the water and bring it out to a storm sewer," Ouderkirk said.
Because it's in a rain forest, the amount of water passing through the treatment plant is quite high, about 1 million gallons a day last month, Oelklaus said. He estimated the tailings dump expansion will add about 200,000 gallons a day.
"We're very cognizant of being within the national monument and operate our system at a higher level than most properties because of the location," Oelklaus said.
Getting a permit for the tailings expansion will take about a year, Ouderkirk said. Besides the meeting Thursday in Juneau, there will be an open house in Angoon the week of April 23. Written comments or questions about the project can also be submitted by fax (747-4344), e-mail (firstname.lastname@example.org), or mail (Greens Creek Mine Project Manager, 8465 Old Dairy Road, Juneau, AK 99801). The application and scoping document can be read on the Web at www.greenscreekeis.com or at the Juneau Public Library.
Kristan Hutchison can be reached at email@example.com.