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Central Interior Mine Tailings Breach Contained, Company Says

What exactly is in the wastewater, and what caused the spill, is still unknown.

Emily Fister 5 Aug

Emily Fister is completing a practicum at The Tyee.

A breach of a tailings pond dam that caused millions of cubic metres of mining wastewater to spill out into central Interior B.C. waterways on Monday has been stopped, the company that owns the dam said today.

The breach at Imperial Metals' Mount Polley mining site near Likely, B.C. released an estimated 10 million cubic metres of water and 4.5 million cubic metres of fine sand into Polley Lake. The reason for the breach is unknown.

"Our first priority is the health and safety of our employees and neighbours, and we are relieved no loss of life or injury have been reported," said the statement from Imperial. "We are deeply concerned and are working to mitigate immediate effects and understand the cause."

The company said it is working closely with provincial ministries, local agencies, and emergency response officials to address the spill.

"This is a serious incident that should not have happened," provincial Minister of Energy and Mines Bill Bennett said today in a statement. "We are devoting every appropriate resource working with local officials to clean up the site, mitigate any impacts to communities and the environment, and investigate the cause of the breach."

Cariboo Regional District, in consultation with Interior Health, has issued a precautionary water ban for the following waterways: Quesnel Lake, Polley Lake, Hazeltine Creek and Cariboo Creek, as well as the Quesnel and Cariboo Rivers systems up to the Fraser River.

The ban does not affect residents of Williams Lake or people living along the Fraser River.

Water sampling expected soon

Although it's still unclear what exactly is in the tailings, Imperial Mines said they are alkaline with an average pH of 8.5, and are not acid generating. According to the CBC, in 2013 Imperial Metals recorded disposing substances such as arsenic, lead, and mercury at the Mount Polley site.

According to the mining ministry, on-site water sampling was conducted last night with results anticipated later this week.

Imperial is currently developing an open-pit copper and gold mine in Red Chris, B.C. Last year, The Tyee reported on a confidential independent review that looked at the reliability of the project's tailings storage.

The report, paid for Imperial Metals at the request of Tahltan Nation, suggested that more work been done to determine how the estimated 300-million tonnes of tailings from the Red Chris mine could affect water in northwest B.C.

Updates will also be posted on the Cariboo Regional District's Emergency Operations Facebook page.

Imperial Metals and the B.C. government have both said they will keep British Columbians updated as more information becomes available. The Tyee will be following the story as it develops.  [Tyee]

Read more: Environment

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