Search

The Island Copper mine in British Columbia, Canada, was an open pit porphyry copper mine which operated from 1971 to 1995. More than one billion t of rock were removed from the open pit. The mine produced metal concentrates containing Cu, Mo, Au, Ag and Re. The operational closure plan included the 1996 decommissioning of the open pit by flooding it with seawater from adjacent Rupert Inlet and capping it with fresh water to create a 355 m deep lake covering 174 ha. The lake provided a receiving environment for acid rock drainage from the mineralised rock deposited around the rim of the pit during operations. The rapid development of meromixis was expected to result in the long-term development of anoxic conditions deep in the lake which would cause metals to precipitate as insoluble metal-sulphides. The site receives high rainfall and has relatively cool summers and mild winters, resulting in a long growing season ideal for vegetation growth. Land reclamation included a nominal 0.5 m soil reclamation cap, contouring and planting of the waste rock dumps with woody vegetation. Currently about 88 000 000 t of waste rock stored over 44 ha of land have waters reporting to the pit lake for remediation. Weekly nutrient amendments are made to the surface of the lake using commercial-grade fertiliser and testing is currently underway to automate injection of fertiliser without the use of a boat. The weekly application rate is equivalent to 382 mg N/m2 and 63 mg P/m2. The phytoplankton biomass in the top and middle layers of the pit lake is primarily composed of the chlorophytes Coccomyxa granulata and Oocystis cf. parva in the winter, spring and summer months and by the chlorophyte Ankistrodesmus falcatus and the diatom Chaetoceros muelleri in the autumn. The same trends in phytoplankton abundance are observed in the middle layer, with the predominant species O. parva dominating the assemblages from February through October. The lake has met its discharge permit limits, whic, The Island Copper mine in British Columbia, Canada, was an open pit porphyry copper mine which operated from 1971 to 1995. More than one billion t of rock were removed from the open pit. The mine produced metal concentrates containing Cu, Mo, Au, Ag and Re. The operational closure plan included the 1996 decommissioning of the open pit by flooding it with seawater from adjacent Rupert Inlet and capping it with fresh water to create a 355 m deep lake covering 174 ha. The lake provided a receiving environment for acid rock drainage from the mineralised rock deposited around the rim of the pit during operations. The rapid development of meromixis was expected to result in the long-term development of anoxic conditions deep in the lake which would cause metals to precipitate as insoluble metal-sulphides. The site receives high rainfall and has relatively cool summers and mild winters, resulting in a long growing season ideal for vegetation growth. Land reclamation included a nominal 0.5 m soil reclamation cap, contouring and planting of the waste rock dumps with woody vegetation. Currently about 88 000 000 t of waste rock stored over 44 ha of land have waters reporting to the pit lake for remediation. Weekly nutrient amendments are made to the surface of the lake using commercial-grade fertiliser and testing is currently underway to automate injection of fertiliser without the use of a boat. The weekly application rate is equivalent to 382 mg N/m2 and 63 mg P/m2. The phytoplankton biomass in the top and middle layers of the pit lake is primarily composed of the chlorophytes Coccomyxa granulata and Oocystis cf. parva in the winter, spring and summer months and by the chlorophyte Ankistrodesmus falcatus and the diatom Chaetoceros muelleri in the autumn. The same trends in phytoplankton abundance are observed in the middle layer, with the predominant species O. parva dominating the assemblages from February through October. The lake has met its discharge permit limits, whic

Rio Algom and Denison Mines operated 11 U mines within the Serpent River watershed, Elliot Lake, Ontario, Canada, which ceased operation in the 1990s. Each mine had its own monitoring programme at the time of decommissioning which had evolved over the operating life of the mine and did not necessarily reflect the monitoring objectives. In 1997 the two companies began reviewing existing environmental data and predicted changes associated with decommissioning, and a monitoring framework was developed which integrated three programmes, the Serpent River Watershed Monitoring Programme which includes water, sediment, benthic invertebrates and fish monitoring at near- and far-field locations, the Source Area Monitoring Programme, which was developed to monitor the nature and quantity of constituents being discharged from tailings management areas to the watershed, and the Tailings Management Area Operational Monitoring Programme, which was designed to track tailings management area performance relative to predictions and support decisions. The programmes provide more meaningful data to allow informed decisions to be made by the mines and federal and provincial regulators. The removal of redundancies and inefficiencies in the previous monitoring programmes resulted in initial cost savings of 60%-70%, and the incorporation of acceptability criteria and response triggers has reduced the scope and cost of the programme by an additional 30%-40%. Environmental conditions in the watershed have improved significantly over the past 10 years., Rio Algom and Denison Mines operated 11 U mines within the Serpent River watershed, Elliot Lake, Ontario, Canada, which ceased operation in the 1990s. Each mine had its own monitoring programme at the time of decommissioning which had evolved over the operating life of the mine and did not necessarily reflect the monitoring objectives. In 1997 the two companies began reviewing existing environmental data and predicted changes associated with decommissioning, and a monitoring framework was developed which integrated three programmes, the Serpent River Watershed Monitoring Programme which includes water, sediment, benthic invertebrates and fish monitoring at near- and far-field locations, the Source Area Monitoring Programme, which was developed to monitor the nature and quantity of constituents being discharged from tailings management areas to the watershed, and the Tailings Management Area Operational Monitoring Programme, which was designed to track tailings management area performance relative to predictions and support decisions. The programmes provide more meaningful data to allow informed decisions to be made by the mines and federal and provincial regulators. The removal of redundancies and inefficiencies in the previous monitoring programmes resulted in initial cost savings of 60%-70%, and the incorporation of acceptability criteria and response triggers has reduced the scope and cost of the programme by an additional 30%-40%. Environmental conditions in the watershed have improved significantly over the past 10 years.

Rio Algom and Denison Mines, together with Elliot Lake Research Field Station, formed a consortium in 1996 to undertake the implementation of a Regional Environmental Information Management System to manage environmental programmes for the decommissioned uranium mine sites and tailings management facilities near Elliot Lake, Ontario. The region's eight tailings management facilities contain 150 000 000 tonnes of potentially acid-generating tailings. Regulatory licensing and permitting requirements for the environmental monitoring programmes are captured by the system and used to drive data collection and to promote consistency in environmental protocols and procedures. Environmental managers use the system to manage regulatory compliance issues. The REIMS system is based on Envista, a commercially available environmental information management system., Rio Algom and Denison Mines, together with Elliot Lake Research Field Station, formed a consortium in 1996 to undertake the implementation of a Regional Environmental Information Management System to manage environmental programmes for the decommissioned uranium mine sites and tailings management facilities near Elliot Lake, Ontario. The region's eight tailings management facilities contain 150 000 000 tonnes of potentially acid-generating tailings. Regulatory licensing and permitting requirements for the environmental monitoring programmes are captured by the system and used to drive data collection and to promote consistency in environmental protocols and procedures. Environmental managers use the system to manage regulatory compliance issues. The REIMS system is based on Envista, a commercially available environmental information management system.

With the completion of uranium mining in the Elliot Lake region of Ontario, progressive environmental technologies and management systems are being utilised to reduce and manage the environmental risks associated with the 150 000 000 tonnes of potentially acid-generating tailings in nine waste management areas. Water covers designed to reduce oxygen entry and inhibit acid generation have been applied at six of the sites. The five effluent treatment plants are monitored and controlled from a central control station using a supervisory control and data acquisition system. Scheduling, auditing and reporting of plant operation and environmental monitoring programmes for the entire watershed are controlled using the Regional Environmental Information Management System. Proper application of these technologies and management systems gives cost-effective environmental monitoring and provides tools to demonstrate compliance with all environmental performance criteria., With the completion of uranium mining in the Elliot Lake region of Ontario, progressive environmental technologies and management systems are being utilised to reduce and manage the environmental risks associated with the 150 000 000 tonnes of potentially acid-generating tailings in nine waste management areas. Water covers designed to reduce oxygen entry and inhibit acid generation have been applied at six of the sites. The five effluent treatment plants are monitored and controlled from a central control station using a supervisory control and data acquisition system. Scheduling, auditing and reporting of plant operation and environmental monitoring programmes for the entire watershed are controlled using the Regional Environmental Information Management System. Proper application of these technologies and management systems gives cost-effective environmental monitoring and provides tools to demonstrate compliance with all environmental performance criteria.