Tailings plan doesn't heed review

Posted by Stop Ajax Mine on January 14th, 2016 4:01am

Tailings Plan Doesn’t Heed Review
Mike Youds, News Kamloops, Jan. 8, 2016

KGHM’s plan to proceed with a modified wet tailings storage facility at Goose Lake is inconsistent with recommendations stemming from the Mt. Polley disaster, says a mine industry watchdog.

Ugo Lapointe, co-ordinator the Canadian program with Mining Watch Canada, said KGHM is being less than forthright with its modified plan.

Clyde Gillespie, KGHM project development manager, told CBC Kamloops Tuesday that the company has adopted an engineering firm’s advice to strengthen the Ajax Mine tailings storage structure in light of the recommendations stemming from the Mount Polley tailings dam collapse.

He said the proposed mine would modify its tailings storage facility (TSF) design with thickened tailings buttressed by dewatered mine rock, building in further safeguards against collapse.

Recommendations from the Mount Polley review panel are for each operation to determine the best technology for their project, Gillespie said.

“That’s a bit of a perversion of what the technical analysis report really says,” said Ugo Lapointe, co-ordinator the Canadian program with Mining Watch Canada, an industry watchdog. “It clearly says the best available technology should be first and foremost and to go with dry stacking.”

The independent review panel’s report on the 2014 Mount Polley TSF collapse, completed a year ago, specifically states:

    Implementing best available technology (BAT) and best available practices (BAP), including using filtered tailings (dry stack) technology where appropriate.
    Enhance validation of safety and regulation of all phases of a tailings storage facility (TSF).

The recommendations did note that there are circumstances where technologies other than dry stacking are more appropriate. KGHM maintains its TSF plan is more appropriate.

KGHM originally planned to use dry stacking for its tailings before it altered its mine plan in 2013.

Community concerns over “lights, noise, dust, proximity to the Coquihalla Highway” and some geotechnical concerns led to the decision to switch to wet tailings storage to the south, Gillespie told the CBC. He earlier told the Vancouver Sun that KGHM rejected dry stacking because it is unproven in a mine on the scale of Ajax, which would process 65,000 tonnes of ore a day, more than three times the amount of mines where dry stacking is employed.

“The reality is, this isn’t as much money and often companies prefer the cheap way,” Lapointe said, referring to wet tailings storage.

According to a Dec. 30 report in the Vancouver Sun, KGHM says it plans to thicken its tailings by squeezing out a lot of the water, increasing the solid content to 60 per cent from the 32 per cent typical of conventional mines tailings.

A TSF that is 80 percent solid, rather than a 60 percent slurry, would be more stable, said Lapointe, who holds a degree in geological engineering.

“There should be a full cost analysis of different plans for storage and costs should not be pre-empting safety,” Lapointe said.  “You want the safest design. Particularly for KGHM, this is really important. The whole waste pile would be sitting on top of the city and, really, if it were to fail, it would likely destroy the city and probably kill people.”

That worst-case scenario must be considered in the mine’s plan, he added.

The company, which intends to submit its environmental permit application later this month, needs to be transparent and forthright with its plans, both with regulators and the public, Lapointe said. The public needs to scrutinize the application to be sure that the plans include ways to minimize damage in the event of a TSF failure like that which occurred at Mt. Polley above Quesnel Lake, he added.

“It’s really important for KGHM to model the worst-case scenario in its design so that everybody can make an informed decision at the end of the day.”


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