BRITISH COLUMBIA – Imperial Metals Corp. has substantially completed the response and recovery phase of cleaning up the Aug. 4 tailings spill at its Mount Polley copper-gold mine 100 km northeast of Williams Lake. The initial work included securing the remaining tails within the impoundment, reducing the water level in Polley Lake, and cleaning up woody debris in Quesnel Lake.
To secure the remaining tails a rock berm was built upstream of the breach. Other berms were built that both improve stability and create sumps to collect water.
Tails and water that reached Polley Lake was trapped there when the outlet became plugged, and the water level rose 1.7 metres. Imperial installed eight pumps and piping to send the water into Hazeltine Creek. The lake level has been returned to the original level and pumping is now required only to maintain that level.
Clean up continues in Quesnel Lake where dislodged trees and shrubs were deposited. Local contractors have secured the floating debris and are removing the beached debris wit the help of two boom boats, a barge and four smaller support craft. Imperial says this work should be finished by mid-November.
Imperial says it has assembled a group of experts to do the rehabilitation and restoration in the areas affected by the breach.
At Hazeltine Creek the road and bridge have been repaired. The channel will be reconstructed and the riparian habitat along the creek banks will be restored. A set of sedimentation ponds is being built to remove suspended solids before the water reaches Quesnel Lake. A revegetation program is planned, and fish habitat will be established.
The outlet of Polley Lake will be restored so that it again connects to Hazeltine Creek. The new channel will be constructed so that fish may migrate between the lake and creek.
Additional information on Mount Polley remediation progress is available at ImperialMetals.com.