Gunnar Uranium Mine Environmental Remediation: Northern Saskatchewan

Thirty-six now-abandoned uranium mine and mill sites were developed and operated in Northern Saskatchewan, Canada, from approximately 1957 through 1964. During their operating lifetimes these mines produced large quantities of ore and tailings. The Gunnar Mine is located on the shores of Lake Athabasca, the 22^nd largest lake in the world. The Gunnar mine (open pit and underground) produced over 5 million tonnes of uranium ore and nearly 4.4 million tonnes of mine tailings. There is an estimated 2,710,700 m³ of waste rock that abuts the shores of Lake Athabasca. After closure in the 1960’s, the Gunnar site along with all of the other uranium mine and mill sites were abandoned with little remediation and no reclamation being done. The governments of Canada and Saskatchewan are now funding the clean-up of these abandoned northern uranium mine and mill sites and have contracted the management of the project to the Saskatchewan Research Council. The clean-up activity is expected to take about 8 years, followed by 10–15 years of monitoring activity before the sites are to be released into an institutional controls program that will allow government oversight of a long term management and monitoring program. The Gunnar site, because of the magnitude of tailings and waste rock, is subject to an environmental site assessment process regulated by both provincial and federal governments. This process requires a detailed study of the projected environmental impacts resulting from the mining activities and an analysis of projected impacts from remediation efforts. Prescribed environmental and land use endpoints will be made based on the environmental assessment studies and remediation options analyzed and implemented based on expected results. Remediation options range from deep lake disposal of tailings to disposal of tailings in the open pit which is now filled with water and fish (contaminated, but which are reproducing successfully) to covering the tailings with a cap. The site also includes many buildings that are remnants of a community of approximately 800 people who once occupied the site. These buildings, many of which contain asbestos, must be appropriately removed and disposed of. The original mine head frame and mill site buildings, many of which still contain the original machinery and equipment, must also be removed and disposed of. The regulatory requirements include the environmental assessment processes, a complex public involvement strategy and licensing from the Canadian Nuclear Safety Commission. The environmental assessment process, specific site studies and public involvement initiatives are underway with the long term goal of releasing the property in a fully remediated state.