The Mount Polley Mine earthen dam in western Canada failed because of a faulty design that didn't consider the geology of the perimeter foundation, an independent review panel says. The Aug. 4 incident dumped 4.5 billion gallons of water and 10.3 million cu yd of mine tailings and construction waste into nearby lakes and rivers.
In its Jan. 30 report, the panel, established to evaluate the cause of the incident, ruled out as causes human error, inadequate inspections, overtopping, or piping and cracking in the embankment. The panel prepared the report for the British Columbia Ministry of Energy and Mines, the Williams Lake Indian Band and the Soda Creek Indian Band.
