Butte has bigger problems anyway. This hill, once called the richest on earth, is known now as one of the dirtiest in America. Its soils and waters are filled with lead and other toxic metals, and the creek called the Silver Bow, which flows at its base, was until recently so contaminated by runoff that it was poisoned at least 140 miles downstream, creating a plume of death that reached into the picturesque Clark Fork River and on toward the Columbia.
In 1983 the Environmental Protection Agency declared that Butte was a high-priority Superfund site—and by the way, that ARCO would have to pay for most of the cleanup. ARCO was taken by surprise. The Superfund laws had been passed in 1980, decades after most of the mess had been made and three years after ARCO bought Anaconda's liabilities. The retroactive application of the laws, though apparently constitutional, seemed unfair. Nonetheless, when threatened with triple damages by the EPA, ARCO did not go to court, as other companies have, but began grudgingly to cooperate. Eighteen years later it remains entangled in what has grown into one of the largest Superfund sites in the United States. The costs of the cleanup have been huge. The site is especially complex because it remains inhabited. The health consequences of the pollution have been only partially studied, but they are widely assumed to be serious—lead poisoning in particular is a concern.
Meanwhile, in Butte's vast underground the shafts and tunnels, full of residual heavy metals and arsenic, have flooded—and the tainted waters have risen within the hill to a level precariously close to that of the rivers and stream-beds on the surface.
Now for the paradox: The mine waters would already be spilling into the Silver Bow, further poisoning it and the rivers downstream, were it not for the existence in the middle of town of the Berkeley Pit, which by serving as a giant sump has delayed the day of reckoning. Five million gallons a day drain into the pit and mix with oxygen to form one of the most contaminated bodies of water in the world—a brown lake of metal-laden sulfuric acid, currently 900 feet deep and steadily rising. The lake is expected to reach the critical level (about 1,100 feet) in another twenty years, at which time—if left alone—it will bleed into the aquifer and poison springs and wells, with catastrophic consequences.
That is unlikely to happen, of course, because Butte is in America, which has the wealth to clean itself up. If Congress lets ARCO off by loosening the Superfund laws (as industry believes it should), then the necessary treatment plant will be built by the EPA instead. One way or the other, the problem will be contained.
Nonetheless, the image of an acid lake is compellingly apocalyptic, and it has come to symbolize Butte's unhappy fate. Much has been made of a flock of migrating geese that landed and died in the poisons of the Berkeley Pit. Butte has been displayed in the press as a moral lesson in environmental self-destruction. Repeatedly it has been called a ghost town, in anticipation of its necessary end.