Environmental Assessment Perspective of Decommissioning and Long-Term Management of Uranium Mine Tailings in Saskatchewan, Canada

Abstract

Abstract Uranium was initially mined in Canada as a strategic mineral, primarily for export to the United States. Currently, uranium is produced for the global energy market and Saskatchewan is the sole producing province in Canada. Uranium development in Saskatchewan dates from 1953 and in 2000 accounted for 31% of global mine production. In the 1990’s the Saskatchewan Government Environmental Assessment Branch reviewed a new generation of uranium mines with large reserves and extremely high average grades. Technically, the development of these mines has required the development of innovative technologies to manage the environmental and occupational health and safety issues associated with the mining of high-grade uranium ores. While the development of these innovative technologies posed a challenge to science and engineering, the potential environmental impacts and level of public concern associated with the development of the high grade uranium deposits equally challenged the ability of the Province of Saskatchewan’s environmental assessment process to evaluate the acceptability of the proposed mines. During the assessment process a major technical, and public, issue was the decommissioning and long-term management of uranium tailings containing high levels of radionuclide and metal contaminants. While technically decommissioning and reclamation are phases of mining that are considered at the end of mine life, scrutiny of these issues during the assessment process contributed significantly to the public and technical acceptability of the proposed mine developments. The design, construction, operation, decommissioning and reclamation of uranium tailings management facilities for the proposed high-grade mines were subject to critical analysis during the technical and public review phases of the environmental assessment processes. Advances in tailings management design, incorporating innovative in-pit disposal methods capable of isolating decommissioned tailings from local groundwater regimes, presented a technical solution to concerns about long-term tailings containment after decommissioning. Public awareness and acceptance of the proposed mine developments was enhanced by the creation of an independent, public inquiry which ran concurrently with the existing federal and provincial assessment processes. The public inquiry was a critical factor, providing an independent forum where the technical acceptability of the proposed long-term tailings management methodologies was discussed. In retrospect the development of the new mines reflects the successful application of an assessment and review process in that the projects met the tests of technical and public acceptability in a process that was seen to be fair, timely, rigorous and public.