Yukon board's questions for Casino mine look ahead 200 years
YESAB questions whether tailings dam can 'remain stable in perpetuity'
Yukon's environmental regulator has provided more than 200 more questions to the proponents of the Casino Mine on the mining project's long term plans.
Ken McKinnon, who is an executive committee member at the Yukon Environmental and Socio-economic Assessment Board, says the mine's plan has to look ahead at least 200 years.
In 2014 proponents of the Casino mine project submitted a 7,000-page proposal to YESAB which was the largest in Yukon history.
McKinnon says YESAB's members read that document and sent 449 questions as a follow-up.
The company responded but some Yukon First Nations and territorial government departments said the response was incomplete. As a result YESAB submitted 224 more questions. McKinnon says a back-and-forth dialogue is expected for a project of this size.
"The proponent has sufficiently answered about half of the questions presented in our Adequacy Review Report but there is still more work to be done before the screening can begin" he said in a news release.
Board questions tailings dam
One major issue is a proposed tailings dam.
McKinnon describes the dam as the same type of dam that collapsed at Mount Polley, B.C. The dam at the Casino mine would contain acid-generating waste rock and is planned for an area with permafrost.
McKinnon says since the dam has a "requirement to remain stable in perpetuity" any plans should consider a changing environment.
He also wonders who would pay remediation costs after the project has closed.
"The design has to take in the concept of climate change because it is a permanent dam foundation," he says.
No officials from the Casino Mining Corporation were available to comment as of May 20.