Inco owns and operates numerous mining properties in the Sudbury, Ontario area including ancillary facilities such as the Copper Cliff Smelter Complex, Clarabelle Mill and Central Tailings Area (R Tailings Area and smelter shown in photos below). In 1998, KCB prepared closure plans and cost estimates for thirteen Inco properties in Sudbury, as well as Port Colborne Refinery in southern Ontario and Shebandowan Mine in northwestern Ontario. Environmental issues at each site were reviewed with Inco personnel and conceptual closure measures were then developed to address long-term physical and chemical stability concerns. Comprehensive capital costs of the proposed closure measures were estimated, as well as the long-term operating and maintenance costs for the closed out sites, all discounted to present values.
Closure issues differed for each site, but most often involved surface water and groundwater quality, acid rock drainage potential, waste rock dumps, landfills, open pits, crown pillars and tailings basins. Proposed rehabilitation measures included site grading plans and new structures for long term surface water management including collection and treatment facilities, improvements to the stability of dams and waste rock dumps, soil covers for leachate reduction, re-vegetation for erosion control, and water quality monitoring programs to evaluate the effectiveness of implemented closure measures.
In June 2000, the government of Ontario proclaimed changes to Regulation 240/00 (Mine Development and Closure) made under Part VII of the Mining Act and asked that Inco resubmit its closure plans in accordance with the revised regulations. KCB was retained in 2001 to undertake this project. Each of the 1998 closure plans were revised to strictly comply with the new regulations and respond to queries from the regulators regarding the 1998 plan submissions and to reflect progressive rehabilitation measures performed over the previous three years. Mine regulators closely audited the resubmitted plans. The updated plans were posted on government registries allowing access by the general public. Completed closure plans can be viewed by contacting the Mines Group of the Ministry of Northern Development and Mines in Sudbury, Ontario.
- Preparation of closure plans
- Closure and long term cost estimates
- Proposal of rehabilitation measures
- Plan revisions