NEWS

Mount Polley Mine tailings pond dam stable: Imperial Metals

08/05/2014 11:07 EDT | Updated 10/05/2014 05:59 EDT
The Vancouver-based mining company whose tailings pond dam failed Monday, sending five million cubic metres of effluent flowing out into waterways in B.C.'s Central Interior, says the breach has stabilized.

Wastewater from Imperial Metals' Mount Polley copper and gold mine near Likely, B.C., has contaminated several lakes, creeks and rivers in the Cariboo region, causing officials to evacuate local campgrounds and enact a number of water use and drinking water bans.

- MORE | Drinking water ban, environmental nightmare at tailings pond breach area

- RAW VIDEO | View from a helicopter over the tailings breach zone

Drinking water and water use bans:

- Quesnel Lake

- Polley Lake

- Hazeltine Creek

- Cariboo Creek

- Quesnel and Cariboo river systems, right up to mouths at Fraser River

​Source: Cariboo Regional District

In a statement released Tuesday morning, Imperial Metals said that, thankfully, no injuries have been reported.

"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," the company said. "We are deeply concerned and are working to mitigate immediate effects and understand the cause."

The company said the tailings are not acid generating and the water is alkaline with a pH of roughly 8.5, but it could not confirm the exact quantity and composition of the discharged wastewater.

In filings made to Canada's National Pollutant Release Inventory in 2013 — which is only one year's worth of data, but gives some idea of what the mine's byproducts are — Imperial Metals recorded disposing of quantities of arsenic, lead, manganese and cobalt, mercury and other harmful mining byproducts.

Mount Polley mine on-site disposal in 2013:

- Arsenic (and its compounds): 406,122 kg

- Lead (and its compounds) 177,041 kg

- Nickel (and its compounds) 326 tonnes

- Vanadium (except when in an alloy): 5,047 tonnes

- Zinc (and its compounds): 2,169 tonnes

- Cadmium (and its compounds): 6,487 kg

- Cobalt (and its compounds): 475 tonnes

- Phosphorus (total): 41,640 tonnes

- Copper (and its compounds): 18,413 tonnes

- Antimony (and its compounds) 14 tonnes

- Manganese (and its compounds): 20,988 tonnes

- Mercury (and its compounds): 3,114 kg

- Selenium (and its compounds): 46,136 kg

Source: NPRI

Imperial Metals also could not confirm what led to the collapse of the earthen dam.

"The dam is an independently engineered structure that operated within design limits and specifications. Monitoring instruments and onsite personnel had no indication of an impending breach," the company said.

Imperial Metals said it is working closely with emergency response officials and provincial ministries, and that it has notified its insurers of the incident.

Imperial Metals, an exploration and mine development and operation company, operates the Mount Polley copper and gold mine in British Columbia and the Sterling gold mine in Nevada.

The company also holds a 50 per cent stake in the Huckleberry copper mine and a 50 per cent stake in the Ruddock Creek lead and zinc property, both of which are in B.C., and is in the process of developing the Red Chris copper and gold property in B.C.

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