The company behind the proposed Casino mine, one of the largest in Yukon’s history and the only to be referred to a panel review, has deferred submitting its revised mine proposal to the territory’s environmental assessment board until the end of next year.
Paul West-Sells, president and CEO of Western Copper and Gold, the parent company, said there’s more engineering and geotechnical work to do on the proposal, known as an environment and socio-economic (ESE) statement.
A partner could also be brought into the fold to advance the project, he added, having to do with its capital cost – worth about $2.5 billion.
The company first submitted its screening proposal for the Casino project in January 2014.
After being bumped to a panel review, the highest level of environmental assessment in the Yukon, the original hope was to submit a revised proposal by the end of 2018.
The proposed project, an open pit copper and gold mine, would be located roughly 300 kilometres northwest of Whitehorse. It would produce 8.9 million ounces of gold and 4.5 billion pounds of copper during its 22 years of operation.
Once the Yukon Environment and Socio-economic Assessment Board (YESAB) receives an ESE statement, that will kick-start the panel review process, spokesperson Rob Yeomans said.
“We see what the project will look like and then we can start asking do we need more information are we ready for the public,” he said.
Further engineering and geotechnical work hinges on a recently released study on how to best manage tailings and mine waste. Because it took longer to pull off — about 18 months — means more time is required, West-Sells said.
“What’s the point of pushing something through that people don’t agree with?” he said. “Then we’re back to square one.”
The results of the best available technology study, which began in 2017, were announced in early November.
At first blush, there were 495 options to deal with tailings and waste, which was narrowed down to two.
Those plans involve zoned storage of “thickened” non-acid generating and potentially acid generating tailings and waste rock in a sand embankment, according to an executive summary of the study.
The mine is projected to produce 956 tonnes of tailings, 20 per cent of which is potentially acid generating, and 658 tonnes of “reactive waste rock and overburden materials,” it says.
“Really what that was,” West-Sells said, referring to the study, “was taking the First Nations, the regulators, the government, getting everybody together, and looking at every possible option in dealing with tailings and mine waste, then whittling that down to an agreed upon solution.”
He called the study a “foundational piece” to the project, the findings of which will not be changed, despite callouts for another business partner.
“I don’t think I’m out of line saying that this tailings facility, at this point, has had the most broadest input of probably any tailings facility ever designed in Canada,” he said. “Obviously this is designed to never fail, but even in the event of a failure, the design now means that that will result in a fairly modest impact on the environment.
“I think Yukoners can feel assured that this is a well studied, well executed and really the best way to deal with tailings and mine waste,” he added.
Contact Julien Gignac at firstname.lastname@example.org