Manitou-Goldex Restoration Project a Win-Win Partnership
Abandoned mine sites are a legacy issue that our industry continues to address.
In 2006, Agnico, while looking for a potential site for storage of the inert tailings that would be produced by its future Goldex mine, approached the Quebec’s Ministry of Energy and Natural Resources (MERN) to partner in the rehabilitation of the abandoned Manitou site near Val D’Or With more than 11 million tonnes of tailings that continued to generate acid mine drainage and release heavy metals into the environment, Manitou was a problem. And with water at pH levels between 2 and 3, aquatic life had been unable to survive in the nearby Bourlamaque River.
The goal of the reclamation project was to stop the acid generation by raising the water table above the reactive Manitou tailings, with the deposition of the inert tailings coming from the Goldex mine some 24 kilometres away. The Goldex mine tailings were free of sulphide, with good neutralization potential, and the process did not use cyanide.
At the time, Agnico Eagle was seeking to put Goldex into production without additional delays or costs. We needed a storage capacity of 24 million tonnes and this solution meant we would not need to build a tailings pond, but instead could use the tailings from Goldex to rehabilitate the Manitou site.
By year-end 2017, 50% of the rehabilitation has been carried out and the effluent had reached neutral pH levels, with a significant decrease in metal loadings to the Bourlamaque River. Aquatic life has also returned to the river.
Mélanie Roy, Environment Coordinator at Goldex says, “The success of this restoration is an example of a win-win partnership and a test case for others to follow. Not only will the Manitou site be reclaimed, but wildlife habitats were recreated and land use was optimized – especially by avoiding the creation of a sizable new tailings storage facility and by reducing the use of natural resources such as sand, gravel, and clay to cover the Manitou tailings. Going forward, tailings and waste rock from operating mines represent opportunities for reclamation work.”
The Manitou reclamation project will continue until Goldex’s planned closure in 2024. A management committee, consisting of representatives from MERN, Agnico Eagle and an independent expert, is responsible for monitoring and managing the project.