On Aug. 4, a pond breach at Mount Polley Mine in British Columbia spilled toxic sediment into nearby streams and creeks. According to the CBC
, 10 billion liters of water and 4.5 cubic meters of metals-laden fine sand contaminated several lakes, creeks and rivers in the Cariboo region.
"That is the equivalent of sending 5,800 Olympic swimming pools worth of wastewater and potentially toxic silt into nearby waterways," the CBC reported.
The spill resulted in a temporary water ban in the region. Global News
reported that experts are calling it one of the worst tailings pond breaches in the world, causing massive destruction to everything in its path. And the government has no idea how much the cost of clean-up will be yet.
The mine is located at the headwaters of the Fraser River, an important watershed for salmon. One estimate
expected 72 million Sockeye salmon to return this summer.
Though this event took place over 900 miles away from Boise, John Robison, public lands director at the Idaho Conservation League
, said it's closer than it seems.
"This is just one of the reasons why ICL and others are concerned about proposed 'state of the art' mines in the headwaters of the Boise and Salmon rivers," Robison said. "Both the CuMo Mine and the Golden Meadows Mine would require similar tailings impoundments upstream of community drinking supplies or critical habitat for salmon, steelhead and bull trout."
The ICL said more than 20 percent of the city of Boise's drinking water comes from the Boise River. It said if a similar failure happened at the proposed CuMo Mine
, it could flow into Grimes Creek, Mores Creek, Lucky Peak and the Boise River.
Midas Gold's Golden Meadows Project
would possibly consist of three open pits in the Salmon River drainage near Yellow Pine. The watershed upstream would potentially be permanently buried under a 400-foot tailings impoundment.