The ribbon of asphalt highway turns to dirt some 20 miles out from the Summitville gold mine, perched high in the San Juan mountains of southern Colorado. The narrow, dusty road climbs through alpine-fir-covered slopes, as if heading to the clouds.
Breasting a ridge not far from the remains of this mining ghost town, the Summitville gold mine becomes eerily apparent: A bald scar cuts across the entire top of South Mountain. A can't-miss sign reads: "Summitville Mine Superfund Site."
It's an unlikely location for a Superfund site - in the heart of this remote mountain territory that edges the Continental Divide. Yet it is home to the most-expensive mining disaster in US history. Between 1986 and 1992, the potent acid used to extract gold seeped into surrounding land and rivers, carrying with it toxic doses of heavy metals.
In 1993, the US Environmental Protection Agency (EPA) grabbed national headlines with its emergency takeover of the open pit mine. Even today, Summitville stands as a reminder of what can go awry in the operation of a cyanide heap-leach mine.
And now Summitville is back in the news: On July 13, Colorado's Water Quality Control Commission downgraded water-quality standards on part of the Alamosa River, which flows past the mine toward the Rio Grande. The downgrading may save taxpayers millions in cleanup costs by easing treatment requirements for water that descends from the mine.
But the move is a controversial one -... pitting local residents and environmentalists against the state and EPA: Locals worry that state and federal officials, in their quest to save money, are forsaking residents and the land. Indeed, the tough question here is much the same as at former mines nationwide: How much reclamation is enough? And at what price?
Cottonwood trees grow tall along the banks of the Alamosa River, offering no hint of the spilled mining waste that wiped out the river's aquatic life. No fish live here even now. "There's enough copper in the river to choke a horse," says John Woodling, a Colorado state biologist.
What's unclear is how pristine the Alamosa was before the Summitville debacle. Was it clean enough to sustain reproducing fish - or already too naturally metal-rich for their survival?
Gold was first discovered in Summitville in 1870. The site was mined off-and-on for more than 120 years. So it's tough to tell if metal concentrations in the river came from mining or nature. Ore that contains gold also tends to carry other metals like arsenic, lead, zinc, copper, and aluminum.
After much study, state officials concluded that metal levels in the river are at least partly due to nature. "The state's position is that there is a natural level of mineralization high enough to affect aquatic life downstream," says Harry Posey, a geochemist with the state Division of Minerals and Geology.
But farmers and ranchers downstream in the agriculture-rich San Luis Valley have relied on the river to water crops and livestock for generations. And now they worry about the potential toxicity.
"Our watchdog has turned on the people it purports to serve," said Ignacio Rodriguez, a rancher from nearby Capulin, at a recent hearing. "If the sheep dog has begun slaughtering the sheep, who is to protect the flock?"
State officials are sympathetic but say the downgrade won't interfere with cleanup goals. "We are continuing to investigate options in the cleanup of the Alamosa River," says Howard Roitman of the state health department.
Tony Martinez - a lawyer representing a large contingent of San Luis Valley residents - sees it differently: "They're essentially saying, 'Hey, it's just a handful of Hispanics in southern Colorado without even a hint of political clout.' It's an opportunity for them to create an environmental sacrifice area."
The EPA, meanwhile, says it is committed to restoring fish to the Alamosa. "Our goal is for it to be a reproducing fishery," says EPA spokeswoman Eleanor Dwight.
Still, the agency does have its eye on limiting costs. To date it has spent $130 million on cleanup. It expects the final bill to be $160 million. At one point, the EPA spent half its annual Superfund emergency budget here. Since then annual costs have dropped to about $3 million - mostly to pay for water treatment to cut copper levels in the river.
EPA hasn't recovered any cleanup costs from the Canadian firm responsible. Galactic Resources Ltd. filed for bankruptcy before abandoning the mine in 1992.
Now reclamation plans at the mine include plugging open pits, diverting water flow, and restoring vegetation to the scarred mountain. EPA hopes these measures will eliminate the need for water treatment within five years.
But others question if it's ever feasible to jettison water treatment. "Acid mine drainage is a chemical reaction of the rock that goes on forever - until the next Ice Age. They have to treat it forever," says Roger Flynn, head of the Western Mining Action Project in Boulder.
CYANIDE leaching has jumped in the past 20 years. It allows mine operators to extract gold from low-grade deposits. Today, dozens of mines around the country safely employ the technique. The mining industry stresses that, when done right, leaching causes no long-term environmental damage.
"Once these mines go through the permitting process required, there's really not much left to chance," says Ivan Urnovitz, spokesman for the Northwest Mining Association, based in Spokane, Wash.
Since Summitville, there are stricter regulations on mining. Moreover, the Summitville disaster did not escape the notice of mine operators, says Mr. Urnovitz: "Certainly, there were lessons to be learned. But the majority of operators do work successfully in compliance with the regulations."