The mine became of international importance when its tailings dam breached in August 2014 causing serious ecological and water quality problems. Processing  During operation, Mount Polley mine processes 20,000 tonnes of ore per day. During processing, this ore is sent for crushing, size reduction, and froth floatation. Remediation Water management and treatment  The long-term water management plan for the Mount Polley mine site has been approved by an independent statutory-decision maker from the Ministry of Environment and is expected to be fully in place by fall 2017 and will replace the short-term water management plan that has been in place since 30 November 2015. Remediation timeline upright=1.5|Fishing on Polley Lake in 2019. Fish habitats were installed on middle and upper Hazeltine Creek during remediation efforts after the Mount Polley dam breachThe Mount Polley Mining Corporation has invested more than $70 million into remediation efforts since the dam breach in 2014. No government funding has been spent on the clean-up or repair work at the site. The restoration and remediation strategy was carried out in four stages: impact reduction, post-breach environmental assessment, long-term health and environmental assessment, and implementation of work focused on remediation to prevent environmental and health impacts and to improve the condition of the areas affected by breach. 2014 In August, MPMC submitted an interim erosion plan and a sediment control plan to mitigate ongoing erosion and sediment transport downstream, to control further flow from the tailings area, and to improve the quality of water flowing into Quesnel Lake. In the beginning of September 2014, a berm to prevent further spread of tailings was nearing completion and laid off workers, about 40 of the mine's approximately 300 workers demanded to reopen the mine. a spokesman at the Ministry of Mine said operations would require permits and approvals and could only go ahead after a rigorous review. The primary phase of the restoration and remediation strategy implemented work to reduce the environmental effect on Quesnel Lake. 2015 upright=1.5|Remediation work to restore wetlands was a priority of the Mount Polley Remediation strategyIn June 2015, the Post-Event Environmental Impact Assessments Report was published as part of the second phase of the strategy. 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. The report detailed steps taken by the MPMC to stabilize the tailings storage facility by creating two rock berms inside the facility, to provide safe access to Hazeltine creek by reducing the elevation of Polley Lake behind the point of the blockage caused by the discharge of tailings effluent, and to stop inputs from the tailings storage facility. Specialists and environmental scientists and engineers were hired to study the impact of the spill from the tailings dam. 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. Chemical studies studied soil, water and sediment changes, while biological studies were focused on the effect of aquatic plant and animal life, in particular those at the sediment layer. Biological assessment also studied soil-dependent biota in the areas surrounding Quesnel Lake and Polley Lake. The Assessments Report determined nine areas requiring ongoing monitoring to determine localized strategies for remediation efforts in each location. These areas included the tailings storage facility, the Polley plug (a blockage area between the tailings effluent and Polley Lake), Polley Lake, upper Hazeltine creek, Hazeltine Canyon, lower Hazeltine creek, the mouth of Edney creek, Quesnel Lake, and Quesnel River. The report concluded that Polley Lake, Hazeltine Creek and a small portion of Quesnel Lake were physically affected by the tailings dam breach. 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. Biological testing found copper contained within lake sediment and within the water was not toxic to aquatic life. Soil testing of copper levels determined a level higher than provincial standards for the protection of invertebrates and plants but at far lower levels than the provincial standards for the protection of human health. Deep water analysis found copper to be at levels below the Provincial Water Quality Guideline. Despite the levels of copper present due to presence in the tailings, the report determined it was unlikely to be released from the tailings and therefore adverse effects were deemed unlikely. The restoration of the shoreline of Hazeltine creek began to create a stable water flow and to begin the restoration of fish and associated wildlife habitats. This was preceded by floodplain grading and the determination of the physical land characteristics of the areas surrounding the shoreline. A flow study to determine an ideal range and the annual mean for natural habitats was completed before construction of rock weirs and habitat features. Planting on the floodplain, to continue over subsequent years had also begun. Repairs to the mouth of lower Edney Creek was completed connecting the waterway to Quesnel Lake. By the spring of 2015, remediation work had installed a new fish habitat at lower Edney Creek. Successful spawning of interior Coho, Kokanee and Sockeye Salmon was accomplished. By May, a new channel for Hazeltine Creek was completed. On 13 July 2015, Interior Health, the regional public health authority, declared all water restrictions lifted and determined water sourced from Polley Lake and Hazeltine Creek safe for consumption and recreation from a health perspective. A review of the water, sediment and fish toxicology samples from the Ministry of the Environment determined no known risks to human health. 2016 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. This work was part of investigation and remediation work ongoing at the Mount Polley site. The detailed site investigation was completed to produce a Human Health Risk Assessment (HHRA) report and an Ecological Risk Assessment for the affected site. The Post-Event Environmental Impact Assessment Report update was completed in June 2015 by Golder Associates. Remediation work was conducted in tandem with investigative work done by Golder. 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. The produced report detailed current recreational and commercial uses of Polley Lake, Quesnel Lake, and Quesnel River and their environs including fisheries, swimming, boating, kayaking, canoeing, waterskiing, snowmobiling, and ice fishing. The report also noted the use of Quesnel Lake as a source of drinking water for nearby residences. As such the report investigated effect of the dam breach on human health, in particular subsistence land users, Quesnel Lake residents, and recreational land users. The HHRA report found that soil, surface water, and the air did not contain contaminants of particular concern that were present or that exceeded contaminated site regulations. The sediment layer exceeded the regulatory standard for lead, while vegetation had copper and vanadium present, and aluminum, copper, and vanadium were present in the fish. The HHRA report concluded that the risks were low to subsistence land users, recreational land users, loggers, and workers on site. Further, the human health risks associated with the tailings storage facility embankment breach were considered to be "very low". Groundwater did contain metals that exceeded drinking water standards including iron, manganese, arsenic, molybdenum, and sulfate. However, no wells that supply groundwater exist in the Hazeltine Corridor. 2017 The HHRA report was published in May. The Ecological Risk Assessment (ERA) report was published in December and detailed the work done by Golder to understand the ecological significance of the tailings dam breach of 2014. The ERA report was completed as a component of the MPMC's remediation strategy to help inform rehabilitation work in affected areas. The ERA considered levels of metal contaminants in the soil, water, and sediment. Territorial and Aquatic risk assessments were concluded as part of the investigative work of the report. 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 tailings decreased soil aeration causing a poor environment for soil biota to support tree growth and survival. The food chain of local wildlife was modeled to determine if copper and vanadium exceeded standards. The cumulative dose according to these models was determined to be below a conservative threshold for most wildlife species. The report concluded low risk associated with copper and vanadium contamination. The bioavailability of the metals was likewise determined to be low. As part of the aquatic risk assessment, copper and arsenic were investigated in the sediment, while copper was the contaminant of potential concern investigated in the water of Polley Lake, Hazeltine Creek, Quesnel Lake, and Quesnel River. 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 plants, water-column invertebrates, and fish in Polley Lake and Quesnel Lake are not expected to face long-term effects of the 2014 breach, according to ERA report. Likewise, risk to fish-consuming wildlife was also determined to be low. 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. The ERA concluded that ecological risks associated with metals released by the dam breach and tailings spill are low. 2018 Over 6 kilometers of new fish spawning and rearing habitats were installed in upper to middle Hazeltine Creek. The successful spawning of Rainbow Trout was later observed in 2018 and 2019 in upper Hazeltine Creek. 2019 The Remediation Plan was prepared by Golder Associates for the MPMC and was submitted to the British Columbia Ministry of Environment & Climate Change Strategy. This was the final requirement of the Pollution Abatement Order which was lifted on 12 September 2019. The Mount Polley Review Panel determined that the environmental effect of the dam breach and tailing spill were the physical disruption of the effluents rather than chemical. MPMC turned its remediation focus to restore physical state of the affected sites. 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. The Mount Polley remediation efforts have replanted 600,000 trees and shrubs to date. The risk from chemical contamination on the site was determine to be low to very low to the relevant terrestrial and aquatic environments. Remediation efforts also repaired 400 metres of shoreline at Quenels Lake and installed new fish habitats at that site. New wetlands were also installed at the site next to the tailings pond failure. Government monitoring, impact, and inspection upright=1.5|Number of exceedances for both drinking water and aquatic life guidelines from all BC Ministry of Environment sample events from August 4, 2014 to August 30, 2016 at Quesnel Lake, British Columbia. Data shows 0 exceedances of listed contaminants by end of 2016. In 2010, provincial government funding was cut for resource management. Preceding the dam breach, Mount Polley was inspected 2013, but not 2011 or 2012. 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]". According to an Imperial Metals summary filed with Environment Canada in 2013, "there was 326 tonnes of nickel, over 400 tonnes of arsenic, 177 tonnes of lead and 18,400 tonnes of copper and its compounds placed in the tailings pond [last year]". At a community meeting on 5 August 2014, the president of Imperial Metals stated "we regularly perform toxicity tests and we know this water is not toxic to rainbow trout." Water, sediment, and fish in Polley and Quesnel Lake are monitored by British Columbia government staff at the Ministry of Environment. Fish sampling in the months immediately proceeding the tailing spill revealed elevated levels of selenium that exceed guidelines for human consumption, though elevated levels of arsenic and copper were not considered a threat to human health. These levels were similar to levels found in 2013 before the tailings breach and considered likely due to local geology. Sediment testing near the tailings spill revealed elevated concentrations of copper, iron, manganese, arsenic, silver, selenium and vanadium. Yet, the government said tests in May 2014, prior to the tailings release, had shown elevated levels of the same elements. 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. In the years after the tailing spill, the extent of the impact of the event has been largely determined. The British Columbia Ministry of Environment provides ongoing water monitoring of pH, conductivity, turbidity, total suspended solids, total dissolved solids, total organic carbon, hardness, alkalinity, nutrients, general ions, total and dissolved metals at the site. Care and Maintenance status As of 31 May 2019, Mount Polley mine was put on care and maintenance status. Remediation work in the areas affected by the 2014 breach has been the focus of Mount Polley's staff from 2014 to 2019. While the mine's affected mining operations it does not impact the ongoing environmental monitoring and remediation programs. Care and maintenance at the Mount Polley mine include management of the water treatment facilities and the operation of site water management systems, including pumps and ditches. Mount Polley monitors the stability of the tailings storage facility on a regular basis. Mount Polley employs 15 staff at the site while it operates in care and maintenance status. The Mount Polley Mining Corporation has stated that it intends to re-open the mine as the price of gold makes mining operations more viable. Imperial Metals history Imperial Metals & Power Ltd was incorporated in British Columbia in December 1959. The company owns the Mount Polley open pit copper mine and gold mine along with the Huckleberry open pit copper mine near Houston, British Columbia and the Ruddock Creek zinc/lead project, near Kamloops, British Columbia. In 2019, Imperial Metals sold its 70\% stake in the Red Chris copper/gold mine to Newcrest Mining for $ 804 million. See also List of copper mines List of gold mines in Canada Geology of British Columbia Water supply and sanitation in Canada Environmental remediation Williams Lake, British Columbia  External links Web site of the review panel Final report of the review panel Mount Polley project site  Government of British Columbia information site Category:Cariboo Regional District Category:Environmental testing Category:Environment of British Columbia Category:Geography of the Cariboo Category:Copper mining Category:Gold mining in Canada Category:Silver mining in Canada Category:Mining in British Columbia Category: Waste disposal incidents Category:Tailings dam failures Category:Environmental engineering Category:Water pollution in Canad
Mount Polley is working toward a reopening in September 2021 to meet the global demand of copper and gold. The Mount Polley Mining Corporation estimates that the reopening of the mine will add 300 local jobs. Processing upright=1.5|Workers at the Mount Polley mine During operation, Mount Polley mine processes 20,000 tonnes of ore per day. During processing, this ore is sent for crushing, size reduction, and froth floatation. Remediation Water management and treatment upright=1.5|Remediated wetlands at Mount Polley The long-term water management plan for the Mount Polley mine site has been approved by an independent statutory-decision maker from the Ministry of Environment and is expected to be fully in place by fall 2017 and will replace the short-term water management plan that has been in place since 30 November 2015. Remediation timeline upright=1.5|Fishing on Polley Lake in 2019. Fish habitats were installed on middle and upper Hazeltine Creek during remediation efforts after the Mount Polley dam breachThe Mount Polley Mining Corporation has invested more than $70 million into remediation efforts since the dam breach in 2014. No government funding has been spent on the clean-up or repair work at the site. The restoration and remediation strategy was carried out in four stages: impact reduction, post-breach environmental assessment, long-term health and environmental assessment, and implementation of work focused on remediation to prevent environmental and health impacts and to improve the condition of the areas affected by breach. 2014 In August, MPMC submitted an interim erosion plan and a sediment control plan to mitigate ongoing erosion and sediment transport downstream, to control further flow from the tailings area, and to improve the quality of water flowing into Quesnel Lake. In the beginning of September 2014, a berm to prevent further spread of tailings was nearing completion and laid off workers, about 40 of the mine's approximately 300 workers demanded to reopen the mine. a spokesman at the Ministry of Mine said operations would require permits and approvals and could only go ahead after a rigorous review. The primary phase of the restoration and remediation strategy implemented work to reduce the environmental effect on Quesnel Lake. 2015 upright=1.5|Remediation work to restore wetlands was a priority of the Mount Polley Remediation strategyIn June 2015, the Post-Event Environmental Impact Assessments Report was published as part of the second phase of the strategy. 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. The report detailed steps taken by the MPMC to stabilize the tailings storage facility by creating two rock berms inside the facility, to provide safe access to Hazeltine creek by reducing the elevation of Polley Lake behind the point of the blockage caused by the discharge of tailings effluent, and to stop inputs from the tailings storage facility. Specialists and environmental scientists and engineers were hired to study the impact of the spill from the tailings dam. 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. Chemical studies studied soil, water and sediment changes, while biological studies were focused on the effect of aquatic plant and animal life, in particular those at the sediment layer. Biological assessment also studied soil-dependent biota in the areas surrounding Quesnel Lake and Polley Lake. The Assessments Report determined nine areas requiring ongoing monitoring to determine localized strategies for remediation efforts in each location. These areas included the tailings storage facility, the Polley plug (a blockage area between the tailings effluent and Polley Lake), Polley Lake, upper Hazeltine creek, Hazeltine Canyon, lower Hazeltine creek, the mouth of Edney creek, Quesnel Lake, and Quesnel River. The report concluded that Polley Lake, Hazeltine Creek and a small portion of Quesnel Lake were physically affected by the tailings dam breach. 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. Biological testing found copper contained within lake sediment and within the water was not toxic to aquatic life. Soil testing of copper levels determined a level higher than provincial standards for the protection of invertebrates and plants but at far lower levels than the provincial standards for the protection of human health. Deep water analysis found copper to be at levels below the Provincial Water Quality Guideline. Despite the levels of copper present due to presence in the tailings, the report determined it was unlikely to be released from the tailings and therefore adverse effects were deemed unlikely. The restoration of the shoreline of Hazeltine creek began to create a stable water flow and to begin the restoration of fish and associated wildlife habitats. This was preceded by floodplain grading and the determination of the physical land characteristics of the areas surrounding the shoreline. A flow study to determine an ideal range and the annual mean for natural habitats was completed before construction of rock weirs and habitat features. Planting on the floodplain, to continue over subsequent years had also begun. Repairs to the mouth of lower Edney Creek was completed connecting the waterway to Quesnel Lake. By the spring of 2015, remediation work had installed a new fish habitat at lower Edney Creek. Successful spawning of interior Coho, Kokanee and Sockeye Salmon was accomplished. By May, a new channel for Hazeltine Creek was completed. On 13 July 2015, Interior Health, the regional public health authority, declared all water restrictions lifted and determined water sourced from Polley Lake and Hazeltine Creek safe for consumption and recreation from a health perspective. A review of the water, sediment and fish toxicology samples from the Ministry of the Environment determined no known risks to human health. 2016 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. This work was part of investigation and remediation work ongoing at the Mount Polley site. The detailed site investigation was completed to produce a Human Health Risk Assessment (HHRA) report and an Ecological Risk Assessment for the affected site. The Post-Event Environmental Impact Assessment Report update was completed in June 2015 by Golder Associates. Remediation work was conducted in tandem with investigative work done by Golder. 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. The produced report detailed current recreational and commercial uses of Polley Lake, Quesnel Lake, and Quesnel River and their environs including fisheries, swimming, boating, kayaking, canoeing, waterskiing, snowmobiling, and ice fishing. The report also noted the use of Quesnel Lake as a source of drinking water for nearby residences. As such the report investigated effect of the dam breach on human health, in particular subsistence land users, Quesnel Lake residents, and recreational land users. The HHRA report found that soil, surface water, and the air did not contain contaminants of particular concern that were present or that exceeded contaminated site regulations. The sediment layer exceeded the regulatory standard for lead, while vegetation had copper and vanadium present, and aluminum, copper, and vanadium were present in the fish. The HHRA report concluded that the risks were low to subsistence land users, recreational land users, loggers, and workers on site. Further, the human health risks associated with the tailings storage facility embankment breach were considered to be "very low". Groundwater did contain metals that exceeded drinking water standards including iron, manganese, arsenic, molybdenum, and sulfate. However, no wells that supply groundwater exist in the Hazeltine Corridor. 2017 The HHRA report was published in May. The Ecological Risk Assessment (ERA) report was published in December and detailed the work done by Golder to understand the ecological significance of the tailings dam breach of 2014. The ERA report was completed as a component of the MPMC's remediation strategy to help inform rehabilitation work in affected areas. The ERA considered levels of metal contaminants in the soil, water, and sediment. Territorial and Aquatic risk assessments were concluded as part of the investigative work of the report. 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 tailings decreased soil aeration causing a poor environment for soil biota to support tree growth and survival. The food chain of local wildlife was modeled to determine if copper and vanadium exceeded standards. The cumulative dose according to these models was determined to be below a conservative threshold for most wildlife species. The report concluded low risk associated with copper and vanadium contamination. The bioavailability of the metals was likewise determined to be low. As part of the aquatic risk assessment, copper and arsenic were investigated in the sediment, while copper was the contaminant of potential concern investigated in the water of Polley Lake, Hazeltine Creek, Quesnel Lake, and Quesnel River. 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 plants, water-column invertebrates, and fish in Polley Lake and Quesnel Lake are not expected to face long-term effects of the 2014 breach, according to ERA report. Likewise, risk to fish-consuming wildlife was also determined to be low. 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. The ERA concluded that ecological risks associated with metals released by the dam breach and tailings spill are low. 2018 upright=1.5|Remediation of Hazeltine Creek at Mount Polley included shoreline restoration and establishment of fish habitats Over 6 kilometers of new fish spawning and rearing habitats were installed in upper to middle Hazeltine Creek. The successful spawning of Rainbow Trout was later observed in 2018 and 2019 in upper Hazeltine Creek. 2019 The Remediation Plan was prepared by Golder Associates for the MPMC and was submitted to the British Columbia Ministry of Environment & Climate Change Strategy. This was the final requirement of the Pollution Abatement Order which was lifted on 12 September 2019. The Mount Polley Review Panel determined that the environmental effect of the dam breach and tailing spill were the physical disruption of the effluents rather than chemical. MPMC turned its remediation focus to restore physical state of the affected sites. 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. The Mount Polley remediation efforts have replanted 600,000 trees and shrubs to date. The risk from chemical contamination on the site was determine to be low to very low to the relevant terrestrial and aquatic environments. Remediation efforts also repaired 400 metres of shoreline at Quenels Lake and installed new fish habitats at that site. New wetlands were also installed at the site next to the tailings pond failure. Government monitoring, impact, and inspection upright=1.5|Number of exceedances for both drinking water and aquatic life guidelines from all BC Ministry of Environment sample events from August 4, 2014 to August 30, 2016 at Quesnel Lake, British Columbia. Data shows 0 exceedances of listed contaminants by end of 2016. In 2010, provincial government funding was cut for resource management. Preceding the dam breach, Mount Polley was inspected 2013, but not 2011 or 2012. 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]". According to an Imperial Metals summary filed with Environment Canada in 2013, "there was 326 tonnes of nickel, over 400 tonnes of arsenic, 177 tonnes of lead and 18,400 tonnes of copper and its compounds placed in the tailings pond [last year]". At a community meeting on 5 August 2014, the president of Imperial Metals stated "we regularly perform toxicity tests and we know this water is not toxic to rainbow trout." Water, sediment, and fish in Polley and Quesnel Lake are monitored by British Columbia government staff at the Ministry of Environment. Fish sampling in the months immediately proceeding the tailing spill revealed elevated levels of selenium that exceed guidelines for human consumption, though elevated levels of arsenic and copper were not considered a threat to human health. These levels were similar to levels found in 2013 before the tailings breach and considered likely due to local geology. Sediment testing near the tailings spill revealed elevated concentrations of copper, iron, manganese, arsenic, silver, selenium and vanadium. Yet, the government said tests in May 2014, prior to the tailings release, had shown elevated levels of the same elements. 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. In the years after the tailing spill, the extent of the impact of the event has been largely determined. The British Columbia Ministry of Environment provides ongoing water monitoring of pH, conductivity, turbidity, total suspended solids, total dissolved solids, total organic carbon, hardness, alkalinity, nutrients, general ions, total and dissolved metals at the site. Care and Maintenance status As of 31 May 2019, Mount Polley mine was put on care and maintenance status. Remediation work in the areas affected by the 2014 breach has been the focus of Mount Polley's staff from 2014 to 2019. While the mine's affected mining operations it does not impact the ongoing environmental monitoring and remediation programs. Care and maintenance at the Mount Polley mine include management of the water treatment facilities and the operation of site water management systems, including pumps and ditches. Mount Polley monitors the stability of the tailings storage facility on a regular basis. Mount Polley employs 15 staff at the site while it operates in care and maintenance status. The Mount Polley Mining Corporation has stated that it intends to re-open the mine as the price of gold makes mining operations more viable. The company is focusing on a reopening date in late 2021. Imperial Metals history Imperial Metals & Power Ltd was incorporated in British Columbia in December 1959. The company owns the Mount Polley open pit copper mine and gold mine along with the Huckleberry open pit copper mine near Houston, British Columbia and the Ruddock Creek zinc/lead project, near Kamloops, British Columbia. In 2019, Imperial Metals sold its 70\% stake in the Red Chris copper/gold mine to Newcrest Mining for $ 804 million. See also List of copper mines List of gold mines in Canada Geology of British Columbia Water supply and sanitation in Canada Environmental remediation Williams Lake, British Columbia Williams Lake First Nation External links Web site of the review panel Final report of the review panel Mount Polley project site Mount Polley Remediation Government of British Columbia information site Category:Cariboo Regional District Category:Environmental testing Category:Environment of British Columbia Category:Geography of the Cariboo Category:Copper mining Category:Gold mining in Canada Category:Silver mining in Canada Category:Mining in British Columbia Category: Economy_of_British_Columbia Category:Cleaning_and_the_environment Category:Natural_resource_management Category:Mining_and_the_environment Category:Environmental engineering Category:Water pollution in Canad
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The mine became of international importance when its tailings dam breached in August 2014 causing serious ecological and water quality problems.
Mount Polley is working toward a reopening in September 2021 to meet the global demand of copper and gold. The Mount Polley Mining Corporation estimates that the reopening of the mine will add 300 local jobs.
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upright=1.5|Workers at the Mount Polley mine
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upright=1.5|Remediated wetlands at Mount Polley
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$70 million into remediation efforts since the dam breach in 2014. No government funding has been spent on the clean-up or repair work at the site. The restoration and remediation strategy was carried out in four stages: impact reduction, post-breach environmental assessment, long-term health and environmental assessment, and implementation of work focused on remediation to prevent environmental and health impacts and to improve the condition of the areas affected by breach. 2014 In August, MPMC submitted an interim erosion plan and a sediment control plan to mitigate ongoing erosion and sediment transport downstream, to control further flow from the tailings area, and to improve the quality of water flowing into Quesnel Lake. In the beginning of September 2014, a berm to prevent further spread of tailings was nearing completion and laid off workers, about 40 of the mine's approximately 300 workers demanded to reopen the mine. a spokesman at the Ministry of Mine said operations would require permits and approvals and could only go ahead after a rigorous review. The primary phase of the restoration and remediation strategy implemented work to reduce the environmental effect on Quesnel Lake. 2015 upright=1.5|Remediation work to restore wetlands was a priority of the Mount Polley Remediation strategyIn June 2015, the Post-Event Environmental Impact Assessments Report was published as part of the second phase of the strategy. 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. The report detailed steps taken by the MPMC to stabilize the tailings storage facility by creating two rock berms inside the facility, to provide safe access to Hazeltine creek by reducing the elevation of Polley Lake behind the point of the blockage caused by the discharge of tailings effluent, and to stop inputs from the tailings storage facility. Specialists and environmental scientists and engineers were hired to study the impact of the spill from the tailings dam. 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. Chemical studies studied soil, water and sediment changes, while biological studies were focused on the effect of aquatic plant and animal life, in particular those at the sediment layer. Biological assessment also studied soil-dependent biota in the areas surrounding Quesnel Lake and Polley Lake. The Assessments Report determined nine areas requiring ongoing monitoring to determine localized strategies for remediation efforts in each location. These areas included the tailings storage facility, the Polley plug (a blockage area between the tailings effluent and Polley Lake), Polley Lake, upper Hazeltine creek, Hazeltine Canyon, lower Hazeltine creek, the mouth of Edney creek, Quesnel Lake, and Quesnel River. The report concluded that Polley Lake, Hazeltine Creek and a small portion of Quesnel Lake were physically affected by the tailings dam breach. 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. Biological testing found copper contained within lake sediment and within the water was not toxic to aquatic life. Soil testing of copper levels determined a level higher than provincial standards for the protection of invertebrates and plants but at far lower levels than the provincial standards for the protection of human health. Deep water analysis found copper to be at levels below the Provincial Water Quality Guideline. Despite the levels of copper present due to presence in the tailings, the report determined it was unlikely to be released from the tailings and therefore adverse effects were deemed unlikely. The restoration of the shoreline of Hazeltine creek began to create a stable water flow and to begin the restoration of fish and associated wildlife habitats. This was preceded by floodplain grading and the determination of the physical land characteristics of the areas surrounding the shoreline. A flow study to determine an ideal range and the annual mean for natural habitats was completed before construction of rock weirs and habitat features. Planting on the floodplain, to continue over subsequent years had also begun. Repairs to the mouth of lower Edney Creek was completed connecting the waterway to Quesnel Lake. By the spring of 2015, remediation work had installed a new fish habitat at lower Edney Creek. Successful spawning of interior Coho, Kokanee and Sockeye Salmon was accomplished. By May, a new channel for Hazeltine Creek was completed. On 13 July 2015, Interior Health, the regional public health authority, declared all water restrictions lifted and determined water sourced from Polley Lake and Hazeltine Creek safe for consumption and recreation from a health perspective. A review of the water, sediment and fish toxicology samples from the Ministry of the Environment determined no known risks to human health. 2016 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. This work was part of investigation and remediation work ongoing at the Mount Polley site. The detailed site investigation was completed to produce a Human Health Risk Assessment (HHRA) report and an Ecological Risk Assessment for the affected site. The Post-Event Environmental Impact Assessment Report update was completed in June 2015 by Golder Associates. Remediation work was conducted in tandem with investigative work done by Golder. 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. The produced report detailed current recreational and commercial uses of Polley Lake, Quesnel Lake, and Quesnel River and their environs including fisheries, swimming, boating, kayaking, canoeing, waterskiing, snowmobiling, and ice fishing. The report also noted the use of Quesnel Lake as a source of drinking water for nearby residences. As such the report investigated effect of the dam breach on human health, in particular subsistence land users, Quesnel Lake residents, and recreational land users. The HHRA report found that soil, surface water, and the air did not contain contaminants of particular concern that were present or that exceeded contaminated site regulations. The sediment layer exceeded the regulatory standard for lead, while vegetation had copper and vanadium present, and aluminum, copper, and vanadium were present in the fish. The HHRA report concluded that the risks were low to subsistence land users, recreational land users, loggers, and workers on site. Further, the human health risks associated with the tailings storage facility embankment breach were considered to be "very low". Groundwater did contain metals that exceeded drinking water standards including iron, manganese, arsenic, molybdenum, and sulfate. However, no wells that supply groundwater exist in the Hazeltine Corridor. 2017 The HHRA report was published in May. The Ecological Risk Assessment (ERA) report was published in December and detailed the work done by Golder to understand the ecological significance of the tailings dam breach of 2014. The ERA report was completed as a component of the MPMC's remediation strategy to help inform rehabilitation work in affected areas. The ERA considered levels of metal contaminants in the soil, water, and sediment. Territorial and Aquatic risk assessments were concluded as part of the investigative work of the report. 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 tailings decreased soil aeration causing a poor environment for soil biota to support tree growth and survival. The food chain of local wildlife was modeled to determine if copper and vanadium exceeded standards. The cumulative dose according to these models was determined to be below a conservative threshold for most wildlife species. The report concluded low risk associated with copper and vanadium contamination. The bioavailability of the metals was likewise determined to be low. As part of the aquatic risk assessment, copper and arsenic were investigated in the sediment, while copper was the contaminant of potential concern investigated in the water of Polley Lake, Hazeltine Creek, Quesnel Lake, and Quesnel River. 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 plants, water-column invertebrates, and fish in Polley Lake and Quesnel Lake are not expected to face long-term effects of the 2014 breach, according to ERA report. Likewise, risk to fish-consuming wildlife was also determined to be low. 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. The ERA concluded that ecological risks associated with metals released by the dam breach and tailings spill are low. 2018 Over 6 kilometers of new fish spawning and rearing habitats were installed in upper to middle Hazeltine Creek. The successful spawning of Rainbow Trout was later observed in 2018 and 2019 in upper Hazeltine Creek. 2019 The Remediation Plan was prepared by Golder Associates for the MPMC and was submitted to the British Columbia Ministry of Environment & Climate Change Strategy. This was the final requirement of the Pollution Abatement Order which was lifted on 12 September 2019. The Mount Polley Review Panel determined that the environmental effect of the dam breach and tailing spill were the physical disruption of the effluents rather than chemical. MPMC turned its remediation focus to restore physical state of the affected sites. 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. The Mount Polley remediation efforts have replanted 600,000 trees and shrubs to date. The risk from chemical contamination on the site was determine to be low to very low to the relevant terrestrial and aquatic environments. Remediation efforts also repaired 400 metres of shoreline at Quenels Lake and installed new fish habitats at that site. New wetlands were also installed at the site next to the tailings pond failure. Government monitoring, impact, and inspection upright=1.5|Number of exceedances for both drinking water and aquatic life guidelines from all BC Ministry of Environment sample events from August 4, 2014 to August 30, 2016 at Quesnel Lake, British Columbia. Data shows 0 exceedances of listed contaminants by end of 2016. In 2010, provincial government funding was cut for resource management. Preceding the dam breach, Mount Polley was inspected 2013, but not 2011 or 2012. 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]". According to an Imperial Metals summary filed with Environment Canada in 2013, "there was 326 tonnes of nickel, over 400 tonnes of arsenic, 177 tonnes of lead and 18,400 tonnes of copper and its compounds placed in the tailings pond [last year]". At a community meeting on 5 August 2014, the president of Imperial Metals stated "we regularly perform toxicity tests and we know this water is not toxic to rainbow trout." Water, sediment, and fish in Polley and Quesnel Lake are monitored by British Columbia government staff at the Ministry of Environment. Fish sampling in the months immediately proceeding the tailing spill revealed elevated levels of selenium that exceed guidelines for human consumption, though elevated levels of arsenic and copper were not considered a threat to human health. These levels were similar to levels found in 2013 before the tailings breach and considered likely due to local geology. Sediment testing near the tailings spill revealed elevated concentrations of copper, iron, manganese, arsenic, silver, selenium and vanadium. Yet, the government said tests in May 2014, prior to the tailings release, had shown elevated levels of the same elements. 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. In the years after the tailing spill, the extent of the impact of the event has been largely determined. The British Columbia Ministry of Environment provides ongoing water monitoring of pH, conductivity, turbidity, total suspended solids, total dissolved solids, total organic carbon, hardness, alkalinity, nutrients, general ions, total and dissolved metals at the site. Care and Maintenance status As of 31 May 2019, Mount Polley mine was put on care and maintenance status. Remediation work in the areas affected by the 2014 breach has been the focus of Mount Polley's staff from 2014 to 2019. While the mine's affected mining operations it does not impact the ongoing environmental monitoring and remediation programs. Care and maintenance at the Mount Polley mine include management of the water treatment facilities and the operation of site water management systems, including pumps and ditches. Mount Polley monitors the stability of the tailings storage facility on a regular basis. Mount Polley employs 15 staff at the site while it operates in care and maintenance status. The Mount Polley Mining Corporation has stated that it intends to re-open the mine as the price of gold makes mining operations more viable. Imperial Metals history Imperial Metals & Power Ltd was incorporated in British Columbia in December 1959. The company owns the Mount Polley open pit copper mine and gold mine along with the Huckleberry open pit copper mine near Houston, British Columbia and the Ruddock Creek zinc/lead project, near Kamloops, British Columbia. In 2019, Imperial Metals sold its 70\% stake in the Red Chris copper/gold mine to Newcrest Mining for $
$70 million into remediation efforts since the dam breach in 2014. No government funding has been spent on the clean-up or repair work at the site. The restoration and remediation strategy was carried out in four stages: impact reduction, post-breach environmental assessment, long-term health and environmental assessment, and implementation of work focused on remediation to prevent environmental and health impacts and to improve the condition of the areas affected by breach. 2014 In August, MPMC submitted an interim erosion plan and a sediment control plan to mitigate ongoing erosion and sediment transport downstream, to control further flow from the tailings area, and to improve the quality of water flowing into Quesnel Lake. In the beginning of September 2014, a berm to prevent further spread of tailings was nearing completion and laid off workers, about 40 of the mine's approximately 300 workers demanded to reopen the mine. a spokesman at the Ministry of Mine said operations would require permits and approvals and could only go ahead after a rigorous review. The primary phase of the restoration and remediation strategy implemented work to reduce the environmental effect on Quesnel Lake. 2015 upright=1.5|Remediation work to restore wetlands was a priority of the Mount Polley Remediation strategyIn June 2015, the Post-Event Environmental Impact Assessments Report was published as part of the second phase of the strategy. 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. The report detailed steps taken by the MPMC to stabilize the tailings storage facility by creating two rock berms inside the facility, to provide safe access to Hazeltine creek by reducing the elevation of Polley Lake behind the point of the blockage caused by the discharge of tailings effluent, and to stop inputs from the tailings storage facility. Specialists and environmental scientists and engineers were hired to study the impact of the spill from the tailings dam. 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. Chemical studies studied soil, water and sediment changes, while biological studies were focused on the effect of aquatic plant and animal life, in particular those at the sediment layer. Biological assessment also studied soil-dependent biota in the areas surrounding Quesnel Lake and Polley Lake. The Assessments Report determined nine areas requiring ongoing monitoring to determine localized strategies for remediation efforts in each location. These areas included the tailings storage facility, the Polley plug (a blockage area between the tailings effluent and Polley Lake), Polley Lake, upper Hazeltine creek, Hazeltine Canyon, lower Hazeltine creek, the mouth of Edney creek, Quesnel Lake, and Quesnel River. The report concluded that Polley Lake, Hazeltine Creek and a small portion of Quesnel Lake were physically affected by the tailings dam breach. 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. Biological testing found copper contained within lake sediment and within the water was not toxic to aquatic life. Soil testing of copper levels determined a level higher than provincial standards for the protection of invertebrates and plants but at far lower levels than the provincial standards for the protection of human health. Deep water analysis found copper to be at levels below the Provincial Water Quality Guideline. Despite the levels of copper present due to presence in the tailings, the report determined it was unlikely to be released from the tailings and therefore adverse effects were deemed unlikely. The restoration of the shoreline of Hazeltine creek began to create a stable water flow and to begin the restoration of fish and associated wildlife habitats. This was preceded by floodplain grading and the determination of the physical land characteristics of the areas surrounding the shoreline. A flow study to determine an ideal range and the annual mean for natural habitats was completed before construction of rock weirs and habitat features. Planting on the floodplain, to continue over subsequent years had also begun. Repairs to the mouth of lower Edney Creek was completed connecting the waterway to Quesnel Lake. By the spring of 2015, remediation work had installed a new fish habitat at lower Edney Creek. Successful spawning of interior Coho, Kokanee and Sockeye Salmon was accomplished. By May, a new channel for Hazeltine Creek was completed. On 13 July 2015, Interior Health, the regional public health authority, declared all water restrictions lifted and determined water sourced from Polley Lake and Hazeltine Creek safe for consumption and recreation from a health perspective. A review of the water, sediment and fish toxicology samples from the Ministry of the Environment determined no known risks to human health. 2016 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. This work was part of investigation and remediation work ongoing at the Mount Polley site. The detailed site investigation was completed to produce a Human Health Risk Assessment (HHRA) report and an Ecological Risk Assessment for the affected site. The Post-Event Environmental Impact Assessment Report update was completed in June 2015 by Golder Associates. Remediation work was conducted in tandem with investigative work done by Golder. 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. The produced report detailed current recreational and commercial uses of Polley Lake, Quesnel Lake, and Quesnel River and their environs including fisheries, swimming, boating, kayaking, canoeing, waterskiing, snowmobiling, and ice fishing. The report also noted the use of Quesnel Lake as a source of drinking water for nearby residences. As such the report investigated effect of the dam breach on human health, in particular subsistence land users, Quesnel Lake residents, and recreational land users. The HHRA report found that soil, surface water, and the air did not contain contaminants of particular concern that were present or that exceeded contaminated site regulations. The sediment layer exceeded the regulatory standard for lead, while vegetation had copper and vanadium present, and aluminum, copper, and vanadium were present in the fish. The HHRA report concluded that the risks were low to subsistence land users, recreational land users, loggers, and workers on site. Further, the human health risks associated with the tailings storage facility embankment breach were considered to be "very low". Groundwater did contain metals that exceeded drinking water standards including iron, manganese, arsenic, molybdenum, and sulfate. However, no wells that supply groundwater exist in the Hazeltine Corridor. 2017 The HHRA report was published in May. The Ecological Risk Assessment (ERA) report was published in December and detailed the work done by Golder to understand the ecological significance of the tailings dam breach of 2014. The ERA report was completed as a component of the MPMC's remediation strategy to help inform rehabilitation work in affected areas. The ERA considered levels of metal contaminants in the soil, water, and sediment. Territorial and Aquatic risk assessments were concluded as part of the investigative work of the report. 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 tailings decreased soil aeration causing a poor environment for soil biota to support tree growth and survival. The food chain of local wildlife was modeled to determine if copper and vanadium exceeded standards. The cumulative dose according to these models was determined to be below a conservative threshold for most wildlife species. The report concluded low risk associated with copper and vanadium contamination. The bioavailability of the metals was likewise determined to be low. As part of the aquatic risk assessment, copper and arsenic were investigated in the sediment, while copper was the contaminant of potential concern investigated in the water of Polley Lake, Hazeltine Creek, Quesnel Lake, and Quesnel River. 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 plants, water-column invertebrates, and fish in Polley Lake and Quesnel Lake are not expected to face long-term effects of the 2014 breach, according to ERA report. Likewise, risk to fish-consuming wildlife was also determined to be low. 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. The ERA concluded that ecological risks associated with metals released by the dam breach and tailings spill are low. 2018 upright=1.5|Remediation of Hazeltine Creek at Mount Polley included shoreline restoration and establishment of fish habitats Over 6 kilometers of new fish spawning and rearing habitats were installed in upper to middle Hazeltine Creek. The successful spawning of Rainbow Trout was later observed in 2018 and 2019 in upper Hazeltine Creek. 2019 The Remediation Plan was prepared by Golder Associates for the MPMC and was submitted to the British Columbia Ministry of Environment & Climate Change Strategy. This was the final requirement of the Pollution Abatement Order which was lifted on 12 September 2019. The Mount Polley Review Panel determined that the environmental effect of the dam breach and tailing spill were the physical disruption of the effluents rather than chemical. MPMC turned its remediation focus to restore physical state of the affected sites. 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. The Mount Polley remediation efforts have replanted 600,000 trees and shrubs to date. The risk from chemical contamination on the site was determine to be low to very low to the relevant terrestrial and aquatic environments. Remediation efforts also repaired 400 metres of shoreline at Quenels Lake and installed new fish habitats at that site. New wetlands were also installed at the site next to the tailings pond failure. Government monitoring, impact, and inspection upright=1.5|Number of exceedances for both drinking water and aquatic life guidelines from all BC Ministry of Environment sample events from August 4, 2014 to August 30, 2016 at Quesnel Lake, British Columbia. Data shows 0 exceedances of listed contaminants by end of 2016. In 2010, provincial government funding was cut for resource management. Preceding the dam breach, Mount Polley was inspected 2013, but not 2011 or 2012. 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]". According to an Imperial Metals summary filed with Environment Canada in 2013, "there was 326 tonnes of nickel, over 400 tonnes of arsenic, 177 tonnes of lead and 18,400 tonnes of copper and its compounds placed in the tailings pond [last year]". At a community meeting on 5 August 2014, the president of Imperial Metals stated "we regularly perform toxicity tests and we know this water is not toxic to rainbow trout." Water, sediment, and fish in Polley and Quesnel Lake are monitored by British Columbia government staff at the Ministry of Environment. Fish sampling in the months immediately proceeding the tailing spill revealed elevated levels of selenium that exceed guidelines for human consumption, though elevated levels of arsenic and copper were not considered a threat to human health. These levels were similar to levels found in 2013 before the tailings breach and considered likely due to local geology. Sediment testing near the tailings spill revealed elevated concentrations of copper, iron, manganese, arsenic, silver, selenium and vanadium. Yet, the government said tests in May 2014, prior to the tailings release, had shown elevated levels of the same elements. 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. In the years after the tailing spill, the extent of the impact of the event has been largely determined. The British Columbia Ministry of Environment provides ongoing water monitoring of pH, conductivity, turbidity, total suspended solids, total dissolved solids, total organic carbon, hardness, alkalinity, nutrients, general ions, total and dissolved metals at the site. Care and Maintenance status As of 31 May 2019, Mount Polley mine was put on care and maintenance status. Remediation work in the areas affected by the 2014 breach has been the focus of Mount Polley's staff from 2014 to 2019. While the mine's affected mining operations it does not impact the ongoing environmental monitoring and remediation programs. Care and maintenance at the Mount Polley mine include management of the water treatment facilities and the operation of site water management systems, including pumps and ditches. Mount Polley monitors the stability of the tailings storage facility on a regular basis. Mount Polley employs 15 staff at the site while it operates in care and maintenance status. The Mount Polley Mining Corporation has stated that it intends to re-open the mine as the price of gold makes mining operations more viable. The company is focusing on a reopening date in late 2021. Imperial Metals history Imperial Metals & Power Ltd was incorporated in British Columbia in December 1959. The company owns the Mount Polley open pit copper mine and gold mine along with the Huckleberry open pit copper mine near Houston, British Columbia and the Ruddock Creek zinc/lead project, near Kamloops, British Columbia. In 2019, Imperial Metals sold its 70\% stake in the Red Chris copper/gold mine to Newcrest Mining for $
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Williams Lake First Nation
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Mount Polley Remediation
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Waste disposal incidents Category:Tailings dam failures
Economy_of_British_Columbia Category:Cleaning_and_the_environment Category:Natural_resource_management Category:Mining_and_the_environment