by Jim Robbins
New York Times news story
BUTTE, Mont. — The recent death of thousands of snow geese on a toxic artificial lake here high in the Rocky Mountains once again underscored the devastating environmental legacy of more than a century’s worth of copper mining.
In the middle of the migratory season, some 3,000 to 4,000 of the large white geese unwarily spread their black-tipped wings and settled down into the acidic wastewater that fills the lake, a 700-acre former open pit mine.
It is not known yet exactly what killed the enormous flock. But the last time large numbers of birds died here — 342 in a 1995 incident — it was because they drank the toxic reddish-brown water and it damaged their brains and other organs.
In a natural spectacle, huge flocks of snow geese have been migrating south from Canada to the southwestern United States, passing through Montana by the tens of thousands. The skies are so crowded in some places that people complain the collective din of flapping wings and honking keep them awake at night.
“We usually see 3,000 to 5,000 in one year,” said Mark Thompson, manager of environmental affairs for the mining company Montana Resources. The company tries to thwart all kinds of birds from alighting atop the toxic lake.
“In this case there were tens of thousands in one night,” Mr. Thompson said. “In the morning, the entire 700 acres of the lake was white with geese.”
Mine employees desperately tried to shoo the birds away before they could ingest too much poisonous water. They used wailers, which produce loud noises; set off fireworks and cracker shells; and fired rifles their way. Nothing worked.
The company then deployed the Goosinator, a large orange remote-controlled boat with a fearsome-looking face that scares birds. But its batteries quickly wore out in the extremely cold weather.
The vast majority of the birds probably were too exhausted from their migratory travels to leave the lake, said Stella Capoccia, an assistant professor in the biology department at Montana Tech in Butte. “They land at night and need to rest for several days.”
A small number of birds did escape, but were found struggling in parking lots and other places around the region. Residents tried to take care of them, and were upset by the deaths.
“People feel for the birds,” Dr. Capoccia said. “It can’t be a comfortable death.”
While thousands of geese left the pit, some might not have made it very far. Hunters in southwest Montana have been advised not to consume the birds they kill. One goose found in Dillon, Mont., appears to have survived the pit and is thriving, giving hope that other geese will be all right.
Climate change also figures into the equation. Because of unusually warm weather, the birds departed from their northern wintering grounds weeks later than usual. By the time they reached Montana, a cold snap had frozen their usual stopping places. The water in the pit, on the other hand, rarely freezes, and the birds saw it as a place to rest on their wearying journey.
Under a federal law that protects migratory birds, a fine of $5,000 could be levied for each dead goose.
Agricultural expansion on the Great Plains has sharply increased the numbers of snow geese, at a rate of about 5 percent annually, to today’s population of about 13 million in North America.
Now, because they are destroying too much vegetation, the federal Fish and Wildlife Service has extended hunting seasons to reduce their numbers.
But thousands of birds are still migrating, putting some at risk of landing in the pit. Montana Resources is installing lasers, like those used at rock concerts, in hopes that birds won’t try to penetrate a gridlike covering of laser beams over the pit.
“There are people with ideas out there,” said Mike McGivern, the company’s vice president for human resources. “Our ears are open.”
The lake, in what is called the Berkeley Pit, was once a mountain where copper and other metals were found in the 1860s. The bonanza led to the boomtown of Butte. A network of mining tunnels honeycombed the so-called Richest Hill on Earth.
In 1955, the Anaconda Company began gobbling up the tunnel-riddled mountain with giant shovels to claim the remaining copper ore; in the process it created the 1,780-foot-deep Berkeley Pit. To keep the pit viable for mining, vast amounts of ground water that poured into it had to be pumped out.
In 1977, Anaconda was purchased by what was then the Atlantic Richfield Company and in 1979 the mine was closed, although Montana Resources operates a much smaller mining operation nearby. In 1981, ARCO stopped pumping water and began letting the pit fill up with the foul brew, as acidic as vinegar, that is created when the water mixes with the exposed earth.
The bizarre lake, surrounded by the multicolored stair-step walls of the open pit, has even become a tourist attraction, complete with a viewing stand and a souvenir shop.
The pit is part of the largest complex of Superfund sites in the country, created by mining waste, and has so far cost nearly $2 billion to clean up. Much of it, especially along streams and the Clark Fork River, has been remediated.
This lake next to downtown Butte is likely to stay forever. As the lake continues to rise, though, it is scheduled to reach the level of Butte’s groundwater by 2023. To prevent that, sometime in the coming years, BP, which now shares responsibility with Montana Resources, will begin pumping and treating seven million gallons of toxic water a day.
“The die-off in 1995 should have been a wake-up call,” said Matt Vincent, the chief executive of the unified Butte-Silver Bow County government, who wants the mining companies to solve the problem. “Instead, we hit the snooze button.”