Balancing Risk: Site Remediation Outside the EnvironmentalAssessment

Abstract

In Canada, an environmental assessment (EA) is typically required for physical works or physical activities that are to be undertaken at a given site, such as those that would be required when performing environmental remediation at an abandoned mine site. In general, the type of EA required under the Canadian Environmental Assessment Act (CEAA) tends to be commensurate with risk, whereby a comprehensive study is required for projects with the potential to cause significant adverse environmental effects.

Remediation of the Gunnar Mine Site, an abandoned uranium mine/mill in Northern Saskatchewan, is currently undergoing a comprehensive EA to develop plans for the sustainable remediation of the Gunnar pit, two waste rock piles, three areas of unconfined tailings and the mine site itself. The site was abandoned in 1964, with little to no remediation. As a result, buildings and structures present on the site deteriorated over time due to scavenging of building materials that had taken place and exposure to the harsh northern conditions.

To address the risks associated with buildings and structures in a timely manner, on July 23, 2010, the Canadian Nuclear Safety Commission (CNSC) issued an Order to address those that have failed a structural safety assessment to be taken down by no later than October 31, 2011 (prior to approval of the Gunnar EA). To accomplish this, it was necessary for the Saskatchewan Research Council (SRC) to plan the work in a safe and cost-effective manner, with consideration of both the short-term mitigative measures required under the Order and the long-term end-state of the Gunnar Mine Site following remediation. Work is proceeding on budget and ahead of schedule on the abatement and demolition of buildings and structures at Gunnar. An overview of the considerations taken, the project accomplishments and the lessons learned will be provided.