Waste for Greening the Wastelands.

• Author: Sankar, Celia
• Position: Pronto Mine, Ontario, Canada; use of paper mill sludge for revegetation - Brief Article

FOR YEARS, efforts to revegetate some sixty-seven acres of tailings from the Pronto Mine in northern Ontario, Canada, stubbornly failed to produce results. The tract of waste material from the former copper mine remained a brown swamp of acidic water where no plant would grow.

Today, however, parts of the tailings are sprouting green shoots of grasses with young poplars stretching up among them. The breakthrough in revitalizing an area damaged by the mining industry has come about through the use of waste material from the pulp and paper industry.

After half a decade of experiments, the Elliot Lake Research Field Station of Laurentian University, commissioned by the mining and milling industries, has seized upon paper mill sludge as a cost-effective, self-sustaining surface material to support plant life.

"Paper sludge can produce good vegetation for years," says Dr. Alexander Okonski, head of the research station's environmental services. "It is a good source of nitrates, phosphates, and potassium, and it holds moisture well."

The Pronto mine closed in 1970, and since 1995 the researchers have made various attempts to revegetate the area that has been problematic because of the near surface water table. They have experimented with spreading rocks, gravel, blast furnace slag, and topsoil. Okonski says that while applying a topsoil cover would be the ideal solution, it is economically unfeasible. Paper mill sludge has proven to be preferable because it is economical as well as environmentally beneficial.

The project, which received approval and technical assistance from the Ontario Ministry of the Environment, is supported by the Northern Ontario Mills and Mines Alliance. The alliance says it intends to use the lessons from the Pronto Mine experiments in land reclamation...