Canadian Consulting Engineer

Mount Polley mine allowed to resume operations

July 21, 2015

Golder report on environmental impact of 2014 spill up for public comment

Golder Associates has prepared a report for the Mount Polley Mining Company providing detailed information about the environmental impacts of the huge tailings pond spill that occurred at the Mount Polley Mine a year ago in south-central B.C.

The disaster on August 4, 2014 occurred when an embankment holding back a tailings pond at the copper and gold mine 50 kilometres northwest of Williams Lake gave way. The spill released 10 cubic metres of mine waste and water into rivers, watersheds and lakes, creating one of B.C.’s worst environmental disasters.

Now, the B.C. government has agreed to let the mining company, which is owned by Imperial Metals, to resume production on a restricted basis. On July 9, Minister of Energy and Mines Bill Bennett and Environment Minister Mary Polak announced the conditional permit to restart operations. The company has to keep its water tailing levels in the existing Springer Pit on the site to 20 metres below the top of the pit edge. It also has to provide several plans to the government, including an updated surface and groundwater monitoring plan for approval by July 31, 2015, a five-year mine plan and reclamation plan by September 30, and a long-term water treatment and discharge plan by June 30, 2016.

So far the company has spent $67 million in remediation work, reports the Ministry, and has held 20 meetings with local residents of Likely, Williams Lake and the Soda Creek Indian Band.


The 73-page “Post Event Environmental Impact Assessment Report – Key Findings” issued June 5 by Golder Associates provides details on the physical, chemical and biological impacts of the spill, and “will inform future work in the area,” says a government backgrounder. The document is available for public comment until September 12.

An earlier report — including 35,000 pages of documentation — was written by an expert panel that investigated the reasons for the disaster and found that the dam’s design was at fault.

Since then, the B.C. government has launched a series of reforms intended to improve mine designs, including “recognizing that cost/benefit “should not supersede safety.”

The government also encouraged the Association of Professional Engineers and Geoscientists of BC (APEGBC) to develop guidelines for characterizing and assessing dam sites. The association is currently developing those guidelines, which will outline the standard of care that engineers and geoscientists must follow when characterizing mine sites. Leading this work is Dirk van Zyl, P.Eng. who participated in the independent expert panel investigations, along with Dr. Brent Ward, P.Geo, Harvey McLeod, P.Eng./P.Geo., and Andy Small, P.Eng.

The Mount Polley Mine Corporation is recalling about 220 workers now that it has permission to resume operations on a restricted basis, which will be about half its normal production rate. Government inspectors will be on site during the start-up period.

Polak said, “Ministry experts made the decision to issue the Environmental Management Act permit based on sound scientific evidence. Their [the company’s] due diligence, along with the extensive First Nations and public consultation that took place with this application provides confidence the permit could be issued without harming the environment.”

“I know the re-start of the mine is welcome news for the communities of Likely, Williams Lake, 100 Mile House and the families that depend on the jobs the mine provides,” said Bennett.

To read Golder Associates’ “Post-Event Environmental Impact Assessment Report for the Mount Polley Mining Company,” released June 5, 2015, click here.

To read the B.C. Government press release of July 9, 2015 on authorizing the mine to restart, click here.

For an initial news brief on the spill in Canadian Consulting Engineer, click here.

To see a recent video on the clean-up by Imperial Metals, click here.



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