The Ministry of Environment has confirmed that a tailings line failed at the Mount Polley Mine on January 23, 2016.
A weekly incident report by Emergency Management BC indicated that the incident was raised to a Code 2 (urgent status) for notification purposes and potential media attention, but was immediately downgraded.
The Ministry says the pipeline broke due to snow removal activity and that 100-150 cubic meters of tailings was contained on site within nearby tailings berms/ditches.
The mill was shut down immediately to stop flow, with the materials cleaned-up.
The Ministry adds that there was no offsite environmental impact.
Imperial Metals who has a permit application which is still under review for the mine to return to full-time operations, was unavailable for comment at publication deadline.