"I'm so angry at this company," said Meri del Rosario, 42, of El Corral, Chile. She has thyroid cancer; two cysts were removed from her throat last year. She blames water pollution from Pascua-Lama.
"If they keep working the valley will end up completely dry, and we'll have to go, and where? I think it's Barrick that has to go," she said.
Some 500 Diaguita have joined a civil lawsuit against Barrick, persuading an appellate court last month to block construction despite the company's denials that it caused any pollution or health problems.
The company's response to the environmental regulator was much more conciliatory: Faced with 23 violations, Barrick accepted nearly all of them, and obtained permission to make urgent repairs.
The violations include building some earthworks without approval, while failing to build others that were supposed to be in place before construction began so that rainfall wouldn't increase the runoff from mineral acids naturally released when rocks are broken. Instead, Barrick went ahead and moved mountaintops in preparation for 25 years of gold and silver production.
Barrick also acknowledged making an "unjustified discharge coming from the acid treatment plant to the Estrecho river" that was "neither declared nor monitored."
The company persuaded the regulator to withdraw an allegation that it had not properly built a huge, impermeable wall that stretches deep below ground and all the way across the top of the Rio del Estrecho valley.
Barrick said the wall stretches for 676 feet (206 meters) across the valley and reaches down as much as 200 feet (62 meters) below the surface, with sealants injected nearly 100 feet (30 meters) deeper still into fissures in the bedrock. It meets U.S. Environmental Protection Agency standards and beats industry standards, the company said.
Despite all this work, inspectors found acid in five test wells below the wall. Barrick challenged the methodology and claimed the acid was there naturally, but after the regulator agreed that the wall met requirements, the company agreed to fortify several wells downstream to collect contaminated water.
Chile's environmentalists, farmers and indigenous communities were thrilled with Friday's ruling, saying it shows only strong oversight can force Barrick to keep its promises.
"One of the concerns we've always had is that they are going to work with an enormous quantity of cyanide," said Leonel Rivera Zuleta, 56, a farmer and member of the Diaguita community of Chipasse Tamaricunga. "Who will assure us that there won't be some kind of accident with this element so poisonous to nature and man?"
Living in adobe homes or concrete houses in the narrow Huasco valley, they tend "the garden of the Atacama," where the river enables them to grow oranges, apples, grapes and vegetables in landscape so barren it's been compared to the surface of Mars.
The Diaguita once followed the rivers up the mountains and roamed over both sides of the frontier, but now Barrick's security guards block their way at a checkpoint just above town. Dump trucks the size of two-story homes and dozens of red barrels with toxic warning labels are kept in a fenced lot nearby.
"The Earth is giving us the strength to be courageous," Diaguita leader Maglene Campillay said, amazed that they're being listened to in a country where mining sustains the economy. "This might be a small community that used to be afraid, but we've united, and we're defending our rights, because we're not going to let them take away our water and end our culture."
Associated Press Writers Michael Warren contributed from Buenos Aires and Eva Vergara from Santiago, Chile. Follow Warren and Henao at: https://twitter.com/mwarrenap and https://twitter.com/LuisAndresHenao