Mount Polley Mine Tailings Dam Breach

The Mount Polley Mine ('the mine') is an operating copper-gold mine operated by Imperial Metals Ltd.

Incident description

Summary

A tailings dam failure at the Mount Polley Mine occurred on August 4, 2014. This resulted in the loss of about 17 million cubic meters of water and 8 million cubic meters of tailings/materials into Polley Lake, Hazeltine Creek and Quesnel Lake with significant impact.

An emergency response was undertaken by the province involving various agencies throughout August and into September 2014. A Pollution Abatement Order under the Environmental Management Act (EMA) was issued on August 5, 2014 and amended several times between 2015 and 2017 to abate the discharge, undertake an environmental impact assessment of the breach and implement remediation activities.

The Pollution Abatement Order was cancelled on September 12, 2019 based on completion of the activities required by the Order. Ongoing monitoring is now a requirement under the effluent discharge permit.

A Letter of Understanding between the province and Soda Creek Indian Band and Williams Lake Indian Band outlines a collaborative approach to jointly address all aspects of the tailings breach.

The ministry led the response for the environmental monitoring, impact assessment, mitigation and remediation of the area impacted as a result of the Mount Polley Mine tailings breach. This work was undertaken with First Nations, local governments, provincial and federal agencies and public representatives.