Post-Mount Polley: Tailings Dam Safety in British Columbia

By: David Chambers, Ph.D., P. Geop.

From the report:

This report assesses the tailings dam designs at four mines in B.C. in light of the recommendations of the Mount Polley Expert Panel to examine whether regulatory agencies are applying best available technology to reduce the risk of catastrophic tailings dam failures, and where they aren’t, if changes could be made to do so.

A comparison of the tailings dam facilities at four BC mines with the Mount Polley expert panel recommendations, demonstrates that:

  • All four of these [projects'] tailings dams involve substantially taller tailings dams (2-6 times the height) storing significantly greater volumes of mine waste tailings (6-27 times the volume) than the Mount Polley tailings dam that failed.
  • None of these four mines meet the recommendations of the Mount Polley expert panel to reduce the risk of tailings dam failure and prioritize public safety.
  • All four mines plan to use same technologies that failed at Mount Polley: wet tailings at closure, rather than the dry tailings at closure recommended by the panel, and the centerline tailings dam design, rather than the safer downstream design.
  • With the exception of the Red Chris Mine,which is already operating, there is still ample time to make changes at all four of the others mines to conform to best practices to better protect public safety and downstream resources.