What happened at Mount Polley?
What happened at Mount Polley?
On Aug. 4, 2014, a four-square-kilometre tailings pond breached at Mount Polley mine in central British Columbia, leaking vast amounts of water and effluent into Polley and Quesnel lakes and Hazeltine Creek. The 40-metre-high tailings dam was built on a sloped glacial lake. That weakened its foundation.
How did Mount Polley fail?
Less than two decades after the Mount Polley mine in British Columbia opened, disaster struck. An investigation into the cause of the spill revealed mine engineers failed to account for glacial silt underneath the tailings containment pond, leading to structural insufficiencies that caused the dam’s collapse.
What was affected by the Mount Polley disaster?
On August 4th, 2014 a four square kilometre sized tailings pond full of toxic copper and gold mining waste breached, spilling an estimated 25 billion litres of contaminated materials into Polley Lake, Hazeltine Creek and Quesnel Lake, a source of drinking water and major spawning grounds for sockeye salmon.
How did the Mount Polley mine disaster affect the environment?
24 million cubic metres of mine waste spilled into nearby waterways when the Mount Polley dam breached in 2014. The Mount Polley mine tailings spill that sent more than 24 million cubic metres of mine waste into nearby waterways in 2014 continues to impact lakes, rivers and aquatic ecosystems, according to a new study.
Are tailings ponds safe?
Research from Canada’s environmental agency has shown that tailings ponds in the tar sands region have leached potentially deadly toxins into land and groundwater, and First Nations tribes and environmentalists have blamed those leaching chemicals from the tar sands on rare cancer clusters.
Are tailings ponds lined?
Tailings ponds are lined with compacted sand and a layer of fine clay. The clay has a low permeability rate which helps prevent tailings water from seeping into the groundwater.
Are tailings dams safe?
Hazard from seismic events Upstream tailings dams are known to have very poor properties during seismic events. During cyclic mechanical stress, as experienced during seismic events, the tailings slurries (including the material used for the dam) may liquefy.
What are the tailings of Mount Polley mine?
Tailings are the leftover material after the minerals that contain the elements of interest have been removed. At Mount Polley (MP), the valuable elements are copper (Cu), gold (Au) and silver (Ag) and they are found most commonly in the sulphide minerals, chalcopyrite (CuFeS
Is the Mount Polley tailings pond toxic to aquatic life?
But Mount Polley’s geochemistry contains relatively low levels of dissolvable metals and minerals that are toxic to aquatic life.
How old are the rocks at Mount Polley?
The rocks that are mined at Mount Polley are around 200 million years old and represent ancient volcanic rocks and magma that intruded into these rocks. The intrusive rocks host the copper, gold and silver mineralization.
When did the dam fail at Mount Polley?
The dam failure and its impacts. On Aug. 4, 2014, the tailings dam of Imperial Metals Corp.’s Mount Polley copper and gold mine near Likely, British Columbia, Canada, failed, releasing 7.3 million m 3 of tailings, 10.6 million m 3 of water, and 6.5 million m 3 of interstitial water into the environment.
