Over the years CVRD Inco had produced a mountain of slag that was threatening to overrun part of Sudbury, Ontario, Canada. The company’s Sudbury facility is one of the world’s largest fullyintegrated nickel, copper and precious metal mining, milling, smelting and refining operations. The slag, a by-product of the smelting process, had become both a dominant feature of the landscape and a major challenge to CVRD Inco’s role as a good corporate citizen and environmental steward. As a result, the company decided to study new ways to accelerate its ongoing reclamation of the slag piles and quickly convert them into green landscape.
An area of the city known as Gatchell had expanded to a point almost adjacent to the slag, and in some areas the two were becoming separated only by a busy roadway. As the slag and the city grew toward a potential “merger,” the company recognized a need to change the materials it had been using for slope reclamation. Mike Peters, CVRD grounds supervisor and greenhouse manager at Sudbury, outlined some of the challenges. • The massive slag accumulation would need to be reshaped, graded and compacted. Because it was adjacent to a roadway with limited land available, the resulting slopes would be steep (gradient of 3H:1V) and in some cases rise to an elevation of 100 feet (30 meters). • Due to the highly acidic nature of the slag, another growth medium (in this case, clay) would have to be incorporated. “We had done slope reclamation elsewhere by hydroseeding using a basic mulch,” Peters said. “But this was on more gradual slopes (4H:1V) and we weren’t completely satisfied with the erosion control. So, we began looking for something more reliable.”