February 13, 2018
PolyMet recently stated that comparisons between the Mount Polley disaster and the proposed PolyMet mine are unfair. In reality the similarities are too striking to ignore.
DNR consultants have warned that at least two of the factors that led to the Mount Polley failure are in common with the PolyMet design: above-ground wet tailings storage on an unstable foundation, and an upstream dam design.
While the proposed PolyMet dam would have a less steep slope than the Mount Polley dam, the overall height of the PolyMet dam would be almost twice as high as the Mount Polley dam, at 252 feet. And, the Mount Polley dam failure was not attributed to the steepness of the slope, but an unstable foundation. If permitted, the PolyMet dam would be built on unstable taconite tailings on top of a wetland.
A Mt. Polley-type catastrophe could happen here, and regular leaking and spills would be all but guaranteed.