The Giant Cup Of Poison

By Richard Woodbury/Butte

In its raucous heyday 80 years ago, this Montana mining town was known as the richest hill on earth. Its rocky soil yielded millions of tons of copper ore, used to make the wires that spread power and light and phones across the nation. Then, 16 years ago, the giant strip mine was closed, and the pumps that kept it dry were turned off for good.

Ever since, waters from the surrounding bedrock and a maze of old mine tunnels and shafts have been rushing in and reacting with the ores to form a toxic soup that rises steadily, year after year, like water in a vast bathtub. It's the Berkeley Pit, and it's a man-made wonder of horrific proportions--an oval lake of acidic mining residues so deep that it could swallow an 80-story skyscraper.

For more than a decade, Butte has been perversely proud of its strange monument. Townsfolk, in fact, celebrate the acid lake, which, deceptively green and picturesque, sparkles on postcards. The Chamber of Commerce runs a trolley to the viewing stand and gift shop that it operates high over the waters. "Biggest tourist draw in southwest Montana," a chamber official crows. But even as visitors stream in, authorities must take elaborate steps to scare away waterfowl with loudspeakers, firecrackers and a boat. Such precautions weren't in place three years ago, when migrating Canadian snow geese had the misfortune to touch down on the waters for a drink. In the following days, officials counted 342 carcasses floating and washed ashore, their insides scoured with burns and sores.

Now those rising waters--26 billion gal.--lap menacingly just blocks from the center of town and 360 ft. below the rim of the pit, threatening one day to spill into an underground aquifer and send a tide of contaminants seeping into neighborhoods and creeks across the Summit Valley. Some people are concerned about a shroud of morning mist and fog--a product of the lake--that envelops parts of the town. "All that moisture has to be carrying bad things in it," says worried restaurateur Buck Loomis.

So, as authorities wrestle with how best to remove and treat the poisons before they reach the danger level, some residents are promoting a new twist on their old livelihood: mining the Berkeley lake. There is growing talk by both local residents and officialdom (scientists and bureaucrats) of seeking to extract perhaps hundreds of millions of dollars' worth of zinc, copper, magnesium and other minerals that lie dissolved in the waters. The alternative--a plan to clean the waters with a standard lime-precipitation technique--has its own problems: critics warn that it could leave the community in the shadow of a mountain of toxic sludge as high as the lake is deep.

ARCO and Montana Resources, the pit's custodians, like the idea of mining the fetid lake but say it is not yet economically feasible. A local environmental firm, MSE Technology Applications, is testing everything from microbes and chemicals to membrane strainers to remove the ores but says a workable process could be years off. That's too long to wait, warns Fritz Daily, a former Montana legislator who is concerned about an earthquake fault less than a mile from the pit. "If the water ever discharges, it could destroy the entire valley," he says. A growing number of others, Montana Senator Max Baucus among them, seem to agree.

Now Daily has a fresh target of anxiety. A disturbing reading in one of 42 monitoring wells surrounding the lake suggests a possible reversal of seepage; instead of flowing toward the pit, the water may be heading away from it.

Old-timers have seen flooding before from the 3,500-mile labyrinth of tunnels and shafts that underlies the town. "Anything could happen down there; nobody really knows where the danger level is," says Frank Beavis, 64, who worked 30 years in the mines. One fear: the waters will rise to invade the aquifer and cause basement flooding and further contamination of Silver Bow Creek, a key waterway, already heavily polluted, that helps form the beginning of the Columbia River.

The Environmental Protection Agency and Montana officials insist that years before the danger level could be reached, some solution--treating the mess or mining it--will be in place to halt the lake's rise. The folk of Butte say they have endured worse crises: bloody labor turmoil in the early 1900s, an underground fire in 1917 that killed 168 men, and a century of giddy booms and sudden busts at the whim of the world price for copper. But Butte's destiny, as has happened before, will ultimately be decided by outside forces. Congress is currently trying to piece together a new Superfund law that could determine how fast--or how slowly--the cleanup of Montana's newest, deepest lake proceeds.