Proposed closure plan amendment submissions for Vale Canada Limited Copper Cliff North Mine, Clarabelle Mill and Copper Cliff Central Tailings Area operations

Vale Canada Limited is in the process of updating their closure plans for the Copper Cliff North Mine, the Clarabelle Mill and the Copper Cliff Central Tailings Area operations, as required under Ontario Regulation 35/24 and the Mining Act of Ontario. The proponent is required to have certified mine closure plans for all mine hazards on site. These closure plans provide rehabilitation measures to be implemented for Copper Cliff North Mine and Copper Cliff Central Tailings Area.

The closure plan amendments are for the expansion of the inactive Murray Mine Open Pit, within the existing closure boundaries of the Copper Cliff North Mine as part of the proposed Copper Cliff Open Pit (CCOP) Project.

The project includes:

• The development of infrastructure to support the project south of the Murray Pit: access road (partly in Clarabelle Mill closure plan area), haul road, railway, vehicle parking space, office complex, maintenance and equipment buildings, and storage area
• The dewatering of the Copper Cliff Open Pit to Pump Lake, at a rate of approximation 5,500 cubic metres per day
• The expansion of the open pit mine
• The development of four waste rock piles, one of which will be partly in the Copper Cliff Central Tailings Area closure plan area
• The development of new water management infrastructure to capture and direct surface water towards the existing water management system
• Progressive rehabilitation measures for the new waste rock piles and the existing Copper Cliff North Mine pits

The following are some of the major components of these closure plan amendments that need to be addressed by the proponent:

• Updates to site infrastructure and mine hazards on sites
• Updates to studies conducted to characterize the site before redevelopment, such as the hydrogeology of the site, the long-term stability of the new waste rock piles and of the expanded pit, the final pit lake elevation…etc.
• Update to the site’s Metal Leaching/Acid Rock Drainage management plan
• Update to the physical, chemical, and biological monitoring programs
• Updates to the proposed closure rehabilitation on sites
• Increased financial assurance for the rehabilitation of the new surface infrastructure, the new waste rock piles, the open pit, the revegetation of the disturbed areas, for the long-term maintenance of the dams, pipelines and pumping systems and for the physical, biological and chemical monitoring of the site

Some of the mine hazards associated with these sites include:

• Water impoundment dams
• Waste rock and ore storage piles
• Open pit
• Surface infrastructure: buildings, parking space, haul road, access road, rail lines, pipelines, hydro lines, equipment, storage tanks
• Petroleum products, chemicals, waste, explosives, septic tank(s)
• Contaminated soils

The required closure plan amendments with accompanying financial assurance will be submitted in a form and manner in accordance with the Mining Act, the Ontario Regulation 35/24, and the Mine Rehabilitation Code of Ontario.