Heavy snowfall has increased the volume of water behind a tailings dam at Imperial Metals’ Mount Polley mine, and concerns are being raised over what could happen as snow melts and the dam’s capacity is overwhelmed.
Soda Creek First Nation Chief Donna Dixon said her people opposed the reopening of the Mount Polley mine in the first place, and they support an expedited release of treated water to avoid potential overtopping.
“We’re looking for a controlled release, as opposed to water going to ground waters and getting into the receiving environment,” Dixon said.
She is hoping the provincial government approves the release sometime this week.
Prior to the Mount Polley tailings pond collapse, concerns had been raised about a buildup of water. Imperial Metals had applied for a permit for a controlled release of water.
In October 2013, the company initiated a permit amendment process to get authorization for the discharge of 3 million cubic metres of water per year of reverse osmosis treated ditch water into Polley Lake.
The Ministry of Environment received the final application for the permit on July 9, 2014 to increase discharge of treated effluent. First Nations had raised concerns about the release, and the tailings pond failed before the controlled release was approved.
A technical report that analyzed the tailings pond’s failure concluded that it was not the pressure from the buildup of water the caused the dam to fail, although it did conclude that the volume of water exacerbated the problem by flooding local waters with more mine waste than might have occurred.
