Imperial Metals Corporation has announced that a tailings dam breach that caused an undetermined amount of water and tailings discharge at Mount Polley mine in British Columbia early Monday morning has stabilized.
The company said the dam had breached in the early morning of August 4, with the cause unknown. There was no loss of life or injury reported, and the company said the tailings discharged are alkaline with an average ph of 8.5 and are not acid generating.
In a statement, it said the dam is an independently engineered structure that operated within design limits and specifications. Monitoring instruments and onsite personnel had no indication of an impending breach.
Mount Polley mine has been placed on care and maintenance, and business interruption and physical damage insurers have been notified. While the damaged area is relatively small compared to the overall size of the dam, it is not known at this time how long it will take to restore operations.
The company said it is "deeply concerned and are working to mitigate immediate effects and understand the cause." It is working closely with provincial ministries, local agencies, and emergency response officials, and further updates will be provided as more information becomes available.