Ajax to take new look at tailings plan

NEWS/ AJAX — In the wake of a report on the causes of the Mount Polley tailings-pond disaster, KGHM Ajax will take a new look at the tailings system to be used in its proposed Ajax open-pit copper mine south of Kamloops, a news report says.

The review panel that brought down a report last week on the Mount Polley tailings-pond disaster of last August says new technologies such as dry-stack tailings systems are one way to reduce the risks of tailings dam breaches.

Dry-stack tailings storage is the method originally proposed by KGHM Ajax. Dry-stack tailings would be piled in an area between Lac le Jeune Road and the Coquihalla Highway near Inks Lake. Concerns over the visibility of the tailings stack from the Coquihalla contributed to a decision by KGHM Ajax to move the proposed tailings area to ranch land purchased at Goose Lake and use a traditional wet tailings “pond” instead of the dry-stack method.

However, that proposed change raised new concerns, this time about its proximity to the Peterson Creek water shed. Those concerns were heightened after the Mount Polley disaster by fears that a breach in the Ajax pond’s dam could send waste into Peterson Creek and into the downtown core.

In turn, that prompted demands for a second public-comment period in view of the changed footprint of the proposed mine.

The panel review’s report on Mount Polley states that “filtered” or dry stack tailings storage is an alternative that should be considered for new mines despite higher cost. “The Panel believes that additional enhancements are ripe for development if there is incentive to do so,” it says of the dry-stack method. “There are no overriding technical impediments to more widespread adoption of filtered tailings technology.”

It says the major reason for the limited use of filtered/dry stack tailings is economic. “Comparisons of capital and operating costs alone invariably favour conventional methods. But this takes a limited view. Cost estimates for conventional tailings dams do not include the risk costs, either direct or indirect, associated with failure potential.”

Kamloops This Week quoted Ajax project manager Clyde Gillespie on Wednesday night as saying KGHM Ajax is “revisiting” the tailings-management plan for the project.

He told the newspaper a “trade-off study” will be done to compare the original dry-stack plan with the current wet-pond proposal. He said the study will take two to three months.

Immediately after the Mount Polley disaster, Gillespie told CBC “for the Ajax project the design that we’re using for the tailings impoundment is the most robust, strongest design that could be used for the embankment…

“The method that we have chosen is the lowest risk, best method for constructing an embankment…. With the proper design, operation of that facility there will be a very, very low risk.”

Comments received from the public by the B.C. Environmental Assessment Office during the second comment period, which closed Dec. 22, mostly opposed the mine and due to concerns about the mine’s impact on the environment, property values, air pollution, proximity to the city, future development and other factors, including references to the Mount Polley disaster.