The potentially catastrophic toxic flood following a tailings pond breach at the Mount Polley mine could have spread hundreds of tonnes of arsenic, lead, nickel and copper
LIKELY, B.C.—An early assessment of the environmental impact of a mine tailings pond failure in British Columbia is expected today when the first water-testing results may be released.
Provincial Mines Minister Bill Bennett has so far said it’s too soon to estimate the damage caused by the Mount Polley Mine breach, but says he hopes for positive news.
The government has promised a thorough investigation into the actions of the provincial government and Imperial Metals in the wake of the June 4 dam collapse.
A tailings pond dam at the mine failed on Monday, sending 10 million cubic metres of water and 4.5 million cubic metres of toxic silt into Polley Lake and Quesnel Lake.
The breach prompted a water-use ban along surrounding lakes and rivers and the B.C. environment ministry has collected water samples in the area.
The company that owns the gold and copper mine in British Columbia where the tailings pond breach occurred has been formally ordered to clean up the site and prevent more material from escaping.
The province’s Environment Ministry said the company received a “pollution abatement order” on June 5.
Under the terms of the order, Mount Polley Mine was required immediately take steps to prevent more waste from escaping into nearby creeks and lakes. The company was also ordered to conduct an environmental assessment and submit a clean-up action plan, with a more detailed plan due the following week.
The province also ordered the company to provide a detailed assessment of the materials that were released, including the anticipated impact on the environment.
“I am hopeful the company is correct in terms of what they say their records show (about what was) in the tailings and that will lead us to positive results, but I don’t know that,” said Bennett.
The minister promised a thorough investigation that will look at both the actions of the provincial government and the company.
“If the company has made some mistakes and is the cause of what happened, it will have to acknowledge that and it will have to bear the costs and responsibility for that,” said Bennett.
A summary of material dumped into the tailings pond filed last year with Environment Canada listed 326 tonnes of nickel, over 400,000 kilograms of arsenic, 177,000 kilograms of lead and 18,400 tonnes of copper and its compounds.
On Monday, the same day as the breach, the company sent the provincial government data about the tailings pond water, B.C.’s Environment Ministry said.
Tests indicated that levels of selenium exceeded drinking-water guidelines by almost three times and organic carbon concentrations exceeded guidelines for chlorinated water. The ministry also said nitrate, cadmium, copper, iron and selenium had exceeded aquatic life guidelines at least sporadically in recent years.
“The ministry would not say that (the water in the tailings pond), based on the characterization, had satisfied drinking water requirements,” said Jennifer McGuire of the B.C. Environment Ministry.
Company president Brian Kynoch apologized to local residents and appeared to downplay the potential dangers posed by the spill. He said the water released from the pond was very close to drinking water. He also said mercury had never been detected in the water and arsenic levels were low.
Grand Chief Stewart Phillip of the Union of B.C. Indian Chiefs said the presence of heavy metals in the tailings could be devastating to salmon.
“I don’t think there’s any question that it’s absolutely catastrophic—it has the potential to devastate the wild salmon stock.
Quesnel Lake and the Quesnel River are considered important breeding grounds for wild salmon, as are other nearby creeks. The system eventually reaches the Fraser River.
With files from James Keller in Vancouver