Demonstration of a Framework for Mine Closure and Relinquishment
CIM Vancouver 2016
Mr Ian Wilson (Remediation Manager, Environment Division - Saskatchewan Research Council), Mr Michael Flynn (Canada Mining Innovation Council), Mrs Denise Chapman (Senior GeoEnvironmental Engineer - O'Kane Consultants Inc.), Mrs Karen Chovan (Principal, Sustainability Advisor - Enviro Integration Strategies)
Mine operators are expected to close out mines such that they meet end land-use plans, and have minimal safety, health, environment, and financial risks. Although advancements have been made in the process, mine closure remains a significant challenge for all major mining jurisdictions around the world. These challenges include the amorphous nature of the process, inconsistencies in regulations across jurisdictions, ambiguous and changing goal points over time, and inadequate management approaches.
To address these challenges, the Canada Mining Innovation Council’s Environmental Stewardship Initiative has prioritized the development of a standardised framework to select risk and performance-based completion criteria for mine closure and subsequent relinquishment. The primary objective of the framework is to provide a clear and consistent path to mine closure by defining the conditions acceptable to stakeholders and Aboriginal groups, and ensuring alignment with end land-use plans, and the respective jurisdictional requirements. The framework will build upon and integrate existing best practices and methodologies for remediation of abandoned sites, for closure planning of existing operations and for design of future developments. It will serve as a key strategic planning and risk management tool for industry, regulatory agencies and mining stakeholders at large. It is also anticipated that its use will enable tailored design and site development, progressive decommissioning, proof of performance during operations, and enable the process of acceptance of closed mines into government and regulatory custody for long-term stewardship.
Complementing the implementation of performance-based regulatory oversight, and successful relinquishment of several closed mine sites in Saskatchewan, a framework concept was used by Saskatchewan Research Council (SRC) to develop completion criteria for the abandoned Gunnar uranium mining and milling site. The site, which operated from 1954 to 1963 in northern Saskatchewan, covers a total of over 70 ha of land, as waste rock and unconfined tailings from the operation were directed to nearby valleys, depressions, and lakes. Requisitioned to manage clean-up of the site, SRC performed a comprehensive Environmental Assessment (EA) and, in 2015, received regulatory signoff from the Government of Saskatchewan to proceed with decommissioning. As part of the EA process, and in conjunction with stakeholder and Aboriginal input, SRC developed Site Specific Remedial Objectives (SSROs), which were generated specifically for the site for all of the identified constituents of potential concern.
CMIC’s initiative, highlighted by SRC’s proof of a framework concept, the benefits of its use, and feedback from collaborating stakeholders and Aboriginal groups, presents a case to convey the practicality of formalizing such an approach, first in Saskatchewan, and then broadening its development, adoption and application Canada-wide.