The former engineer of the Mount Polley mine-tailings facility has declared that it warned B.C.'s chief inspector of mines, Al Hoffman, and the mine's owner in February 2011 about the storage facility.
"The embankments and the overall tailings impoundment are getting large and it is extremely important that they be monitored, constructed and operated properly to prevent problems in the future," Knight Piésold Ltd. managing director Ken Brouwer and president Jeremy Haile wrote in a letter to Imperial Metals Corporation CEO Brian Kyonoch.
Knight Piésold stated in an August 8 news release that it has "not had any responsibility or knowledge of any aspects" of what's taken place there since February 10, 2011.
On that date, the Vancouver office of Knight Piésold told Imperial Metals Corporation that it would no longer be the engineer of record.
"The original engineering done by Knight Piésold Ltd. accommodated a significantly lower water volume than the tailings storage facility reportedly held at the time of the breach," Knight Piésold stated. "Significant engineering and design changes were made subsequent to our involvement, such that the tailings storage facility can no longer be considered a Knight Piésold Ltd. design."
The engineering company called the breach of the tailings facility "an extremely unfortunate incident and Knight Piésold Ltd. shares the concerns with respect to the effects to local communities, First Nations and the environment".
Approximately 10 million cubic metres of water containing toxic waste from the mine flowed into Hazeltine Creek and Polley Lake on August 4.
"A formal handover of design, construction and monitoring responsibilities was conducted on March 8, 2011 when AMEC Earth and Environmental was acknowledged as the new Engineer of Record for all future work at the Mount Polley tailings storage facility," Knight Piésold stated.
The company added that it "is not familiar with, and therefore cannot comment on, the details of the incident, or on the design, construction, operations, water management practices or any other aspects of the Mount Polley tailings storage facility".