Recent Mining Disasters Underscore Significant Challenges Posed by Huge Open Pit Mining Projects – by Frances Causey (Huffington Post – September 9, 2014)

Frances Causey is a documentary filmmaker and journalist.

The Mount Polley mining disaster on Aug. 4 in Canada’s Cariboo Regional District is being called possibly the worst environmental disaster in British Columbia history. A tailings dam collapsed at an open pit copper and gold mine tailings dump, sending huge volumes of toxic waste into critical waterways 370 miles north of Vancouver, British Columbia. The environmental catastrophe wreaked havoc throughout the region, initiating an emergency drinking water ban, severely damaging the region’s important sockeye salmon habitat, a critical food and income source for the area’s First Nation’s communities and abruptly putting a halt to the area’s vibrant tourism.

Years before the disaster, the B.C. Ministry of Environment repeatedly warned the Mt. Polley mine owner, Imperial Metals, that the waste water level of the Mt. Polley tailings pond was too high. The Mt. Polley spill is being compared to the Exxon Valdez disaster in 1989, which spilled 11 million gallons of crude oil into Prince William Sound in Alaska.

The area around the Valdez spill contained a thriving spring herring fishery that has not fully recovered and may never, according to government scientists. The impact and cost to clean up the Mt. Polley spill is still being evaluated and will be for years to come, but one can’t help but wonder what the sockeye salmon run there will look like in 25 years.

And just last week, 25 miles across the border from Arizona, Grupo Mexico’s Buenavista copper mine in Canenea, Sonora, had a tailings dump failure that poured 10 million gallons of copper sulfate acid into a river that supplies water to tens of thousands of people living in rural areas along the Rio Sonora. The river of orange poison reportedly is killing livestock and wildlife.

These mining disasters undoubtedly increase the concerns of southern Arizonans who have been warning for years about threats from the proposed mile-wide, and half-mile deep Rosemont open-pit copper mine. The mine would sit just miles south of Tucson, the state’s second largest city. For example, it turns out that the current tailings dam engineer at Mount Polley, AMEC, is also the lead designer of Rosemont’s tailings dump, which would be by far the largest of its kind ever attempted.

While the dry stack tailings dump proposed for Rosemont does not have a pond like the ones that failed in Mexico and Canada, they do have the potential for high levels of airborne dust emissions and leaching of liquids laced with toxic metals and other substances. In fact, the Arizona Game and Fish Department specifically warned that water from Rosemont could leach highly toxic metals from the dry stack tailings and contaminate downstream waterways for up to 500 years. Two of those, Cienega Creek and Davidson Canyon Creek, are classified as Outstanding Arizona Waters and protected by Arizona state law from any degradation.

HudBay Minerals, which bought the Rosemont mine earlier this year, recently announced plans to drill new exploratory holes for a possible expansion of what already would be the third largest copper mine in the country. A larger mine means a deeper pit and far more waste rock and tailings, all which could have greater negative impact on sparse surface and ground water supplies.

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