Mount Polley collapse 1-year anniversary: Mines Minister says industry still horrified

British Columbia's mines minister says the mining industry remains horrified a year after a tailings pond collapsed at the Mount Polley mine northeast of Williams Lake.

Bill Bennett said no one thought a crisis on such a scale was possible but that even now he can't guarantee that another breach of a tailings pond won't happen because only some of the risk factors can be eliminated.

"We didn't eliminate enough of the risk and we have to figure out, and we are figuring out, how to eliminate the rest of that risk," he said of the Aug. 4, 2014 accident.

About 24 millions cubic metres of waste spilled into area waterways, causing an environmental disaster.

"It totally destroyed the creek that comes out of Polley Lake and flows past the tailings storage facility, past the mine, down into Quesnel Lake," Bennett said. "You had millions of trees and roots and mud and all kinds of stuff in Quesnel Lake. It looked horrible, it was horrible."

Many lessons for mining industry

Imperial Metals, which operates the gold and copper mine, has spent about $67 million on cleanup of the region, repair of the damaged bed of Hazeltine Creek and monitoring of water quality in area lakes.

Karina Brino, president of the Mining Association of B.C., said much has been learned since the collapse of the tailings pond.

The industry has been forced to take a close look at all practices surrounding the construction, maintenance and use of tailings ponds, Brino said.

She said accidents will happen but that investigators remain focused on the root causes of the collapse and that mitigating risk is the industry's biggest challenge.

An independent report determined poor dam design caused the tailings pond to collapse.

The provincial government has spent $6 million on the cleanup, and Imperial Metals was granted conditional approval to reopen last month, although it still needs further permits before it can operate fully.

Bennett said water and sediment testing will have to continue for decades.