Mt. Polley says after having considered all of their options for site alternatives for tailings management, their original tailings storage facility which burst on August 4, 2014, is the best option.
Imperial Metals Vice President of Corporate Affairs Steve Robertson says he believes it’s important for the public to be involved with the conversation so they can feel comfortable with the decision.
“Obviously there had a been a breach there and that is not something that is going to be overlooked or forgotten about soon,” he says.
“We need to have a conversation so that people can understand the amount of work and thought and effort that has gone into looking at the reuse of the facility and all of the conditions around that.”
Robertson adds that the Mine is in agreement with all of the recommendations from an expert panel report released in January of 2015.
“I think that that panel report was very clear that the failure had a single cause and the single cause was an engineering design flaw-it didn’t take into the foundation conditions below the dam. I don’t think that anything we’re doing now would be inconsistent with the panel report or the review recommendations.”
Engineer with Golder Associates, Andy Haynes says they have considered all options including storing tailings in lakes, a new tailings storage facility, and also storing tailings in an open pit and underground.
He says a new tailings storage facility, regardless of the technology would require a newly disturbed area of about one and a half to two and a half square kilometers-about the same size of the existing storage facility.
“It (TSF) has had a significant amount of investigation since the breach and engineers have been looking very carefully at the basement or foundation conditions below where the structure is built so they have a very clear understanding of what those conditions are and the facility’s been re-engineered.,” says Robertson.
“There’s actually a design that would enable it to go right back to the crest height of 970 which is where it was before and even higher, and to accommodate for the more conservative design they actually have additional buttressing that’s going to be included in the design.”
Mt. Polley says they are hoping to transition from their restricted operations permit to full-time by April 1, 2016.
310 individuals are currently employed at the mine.
An independent peer review panel is set to meet for a third time on Dec. 21 to confirm that the design and operation of the tailings storage facility are consistent with industry best practices.