The metres-thick layers of minerals, soil and vegetation used to cover tailings and waste rock at decommissioned mines need to prevent hazardous materials from leaching to surface water for centuries into the future.
A new research testing facility unveiled Thursday at the University of Saskatchewan’s Global Institute for Water Security will be used to better understand how those “cover systems” respond to weather and other natural elements like tree roots, burrowing animals and insects, said Jeffrey McDonnell, head of the Global Institute for Water Security’s Mine Overlay Site Testing (MOST) facility.
Until now, the only way for a mining company to know how to isolate waste was to use computer modelling to design a layered system based on predictions of how a particular site would respond to the environment and then build an actual test site at the mine and monitor it for five or 10 years. Mine closure is one of the largest costs of the mining enterprise, McDonnell said.