A mined-out pit used to store wastewater and milling leftovers at B.C.’s Mount Polley Mine is expected to fill up in April. The B.C. government just issued a permit allowing treated pit water to be discharged into a nearby lake to prevent overflow. (Monica Lamb-Yorsk/Williams Lake Tribune)
A British Columbia mine that’s become a poster child for environmental disasters will soon begin discharging wastewater.
The Mount Polley Mine’s tailings dam broke in August of 2014, releasing more than 6 billion gallons of silty water and mine-processing leftovers.
The provincial government granted permission to resume partial operations in July. But Mount Polley wasn’t allowed to discharge anything off its site. Instead, waste and water were routed to a large, mined-out pit.
Officials from a nearby town and two tribal governments recently warned the pit was close to full and could spill water and waste rock.
But British Columbia officials this week issued a permit allowing some of that to be treated and released.
Mount Polley Mine’s tailings dam breached in August of 2014, releasing silty wastewater. (File photo)
Mining Minister Bill Bennett said there was no chance it would overflow and damage the environment anytime soon.
“The pit that the water and the tailings are going into is not close to, anywhere close actually, to the water being at the top. It’s not a situation where you have a potential for a breach or an overtopping at all,” Bennett says.
“It’s unfortunate that statements were made by those who really don’t have the facts.”
B.C.’s environment ministry says without releasing some water, the temporary tailings pit would overflow next April.
The new permit approves the mine’s plans for wastewater to go through a treatment plant and into a settlement pond. It will then be released about 100 feet below the surface of a nearby lake, the deepest in British Columbia.
The CBC reports compliance with drinking water standards will be measured about 300 feet from the discharge point, at the edge of a dilution zone.
Mount Polley is within the watershed of the Fraser River, which empties into the Pacific Ocean at Vancouver, B.C.
The Southeast Alaska Conservation Council’s Guy Archibald says it still should concern residents “because this is what we’ve come to expect from the B.C. permitting process,” Archibald says.
“For the mines that do drain into the transboundary rivers and potentially eventually into Southeast Alaska, we can expect the same, very shortsighted, rubber-stamp permitting process.”
Mount Polley’s proposed water-treatment system is temporary. Owner Imperial Metals must submit a long-term plan by the end of June.
The B.C. government says the treated water will be monitored. It must be safe for drinking and as well as aquatic organisms.
Watch a government video of the reclamation project.
Watch a critical video about the reclamation work.
Editor’s note: This report was updated with additional information about how the discharged water will be sampled.
