Yukon board's questions for Casino mine look ahead 200 years

Yukon's environmental regulator has provided more than 200 more questions to the proponents of the Casino Mineon the mining project's long term plans.

KenMcKinnon, who is an executive committee memberat the Yukon Environmental andSocio-economic Assessment Board, says the mine'splan 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 Yukonhistory.

McKinnon says YESAB's membersread that documentandsent 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 resultYESABsubmitted 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 ina newsrelease.

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 thedam has a "requirement to remain stable in perpetuity" any plans should consider a changing environment.

He also wonders who would pay remediation costsafter 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.