Geosynthetic liners for sustainable development of Arctic mineral resources

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Extraction of mineral resources contributed $56 billion to Canada's economy in 2015. More than $8 billion in new mineral resource development is anticipated in the next decade alone in the Canadian Arctic. These activities involve generation of contaminated water that needs to be managed in a sustainable manner to maintain and help grow this vital economic activity while protecting surface and ground water supplies, and the sensitive Arctic ecosystem. These waters include runoff through acid generating waste rock piles and end of process wastes from mining called tailings, which largely consist of soil size particles, soluble salts and water. Large piles or impoundments are commonly used to contain these wastes. To minimize ground and surface water contamination they need to be contained in a safe but economically feasible manner. Geomembranes (plastic sheets typically 1-2.5 mm thick) and geosynthetic clay liners (a 5-7 mm thick layer of clay encapsulated between two layers of textile) are being considered as liners on top of waste rock piles (i.e., as an engineered cover to limit the movement of water and air through the waste to a negligible level) and on the bottom of tailings impoundments (i.e., as an engineered barrier to reduce the quantity of contaminants from escaping into the surrounding environment). These geosynthetic liners have been used to significantly enhance environmental protection at municipal landfills. However, there is little specific data to permit their rational design and long-term assessment in Arctic conditions, especially considering the effects of global climate change. Research is needed to allow an assessment of how much fluid may be expected to leak through the liner and how long the liner will last when exposed to the chemicals and physical stresses in Arctic applications. The aim of this partnership between university researchers, engineering consultants, and geosynthetic manufacturers is to establish a scientifically sound technical basis for the design of geosynthetic liners to enable the sustainable development of Arctic mineral resources. The research will provide specialized training for six highly qualified personnel in an area of economic and environmental importance for Canada.