About 50 staff include administrators, supervisors, warehouse operators, engineers, geologists, assayers, technical personnel, and human resources.

The deposits are located in the Quesnel trough, a Mesozoic volcanic arc in the Canadian segment of the North American Cordillera.

[11] Quintana Resources prospected the area in 1976, discovering numerous copper float boulders but let their claim to the property lapse in 1978.

[13] Subsequent to the discovery of the white pit, after additional underground mining, another site was discovered and developed called "Martel".

[16][17] Early reactions to the tailings spill expressed grave concern, but no fines or charges against Imperial Metals have been assessed.

[18][19][20] On August 6, two days after the breach, the British Columbia Ministry of Environment issued a Pollution Abatement Order to Mount Polley Mining Corporation.

[24] Several local landowners and business operators affected by the spill have launched legal challenges to seek compensation for damages.

The report found that the tailings dam collapsed because of its construction on underlying earth containing a layer of glacial till, which had been unaccounted for by the company's original engineering contractor.

[17] In 2010, Mount Polley Mining Corporation's (MPMC) engineering firm reported a 10-metre (33 ft) crack in the earthen dam while working to raise it, and that piezometers were broken, which were later fixed.

Mount Polley Mining Corporation submitted its formal permit amendment application, which included the long-term water management plan and supporting Technical Assessment Report, in October 2016.

[38] The report was submitted by Golder Associates to the Mount Polley Mining Corporation to determine the physical, biological, and chemical implications 6–8 months after the dam breach.

This team studied where tailings effluent was deposited on land and in surrounding water environments, in particular how the bottom of Quesnel Lake was affected and how the structures of Hazeltine and Edney creeks had changed.

[38] The chemical testing on the tailings mixture was determined to be relatively inert though it was found that a higher concentration of copper was contained in the effluent compared to before the breach.

A review of the water, sediment and fish toxicology samples from the Ministry of the Environment determined no known risks to human health.

[39] A detailed site investigation was completed by Golder Associates in January 2016 as mandated by the Pollution Abatement Order issued by the British Columbia Ministry of Environment.

The Human Health Risk Assessment (HHRA) was completed by Golder Associates as part of that company's work toward implementing the Mount Polley remediation strategy.

Groundwater did contain metals that exceeded drinking water standards including iron, manganese, arsenic, molybdenum, and sulfate.

The ERA report was completed as a component of the MPMC's remediation strategy to help inform rehabilitation work in affected areas.

The report found excess concentrations of copper and vanadium in the soil however it was determined that the tailings were not acid generating and were unlikely to leach metals.

The ERA determined the cause of some tree death post-breach and attributed a root smothering effect of the tailings effluent in the forested region.

It was determined that copper levels decreased below the accepted guideline through 2015 in both lakes and Quesnel River, but not in Hazeltine Creek which was the site of active remediation and restructuring.

The deep ecological benthic ecosystem was also considered to have little risk from copper as a limiting factor in the recovery of these organisms at the sediment layer.

[42] The Remediation Plan was prepared by Golder Associates for the MPMC and was submitted to the British Columbia Ministry of Environment & Climate Change Strategy.

The Mount Polley Review Panel determined that the environmental effect of the dam breach and tailing spill was the physical disruption of the effluents rather than chemical.

The remediation efforts include ongoing planting of trees and shrubs that are native to the local ecosystem in the riparian and upland areas along Hazeltine Creek.

Bill Bennett, Minister of Energy and Mines, said "there is no evidence that the government's missed inspections were related to the failure of the dam [in 2014]".

"[16] Water, sediment, and fish in Polley and Quesnel Lake are monitored by British Columbia government staff at the Ministry of Environment.

[43] Sediment testing near the tailings spill revealed elevated concentrations of copper, iron, manganese, arsenic, silver, selenium and vanadium.

[44] By 2016, Ministry of Environment testing determined zero exceedances of its guideline levels for contaminants for both aquatic life and drinking water in Quesnel Lake.

[46] Imperial Metals temporarily suspended operations of the Mount Polley mine in 2019 due to declining copper prices.