Development and implementation of a decommissioning and closure plan at the Premier Gold Project Mchaina, David Mhina
This paper describes the development and implementation of a decommissioning and closure plan at the Premier Gold Project. The Property is located approximately 18 km north of Stewart, British Columbia, Canada and 2.4 km northeast of the BC/Alaska border. The site has been used for gold and silver mining since the turn of last century and Boliden Limited has owned and operated the site since 1988. Mining operations ceased in 1996 and the mine is proceeding through a closure phase. The main objective of the decommissioning and closure plan is to minimize the impact of tailings, contaminated water discharges, waste rock dumps and other aspects of the site on the receiving environment. The main aspects of the closure plan include decommissioning and closure of the Tailings Storage Facility (TSF), demolition of buildings, disturbed areas re-vegetation and environmental performance monitoring. The closure plan for the TSF calls for a partial wet closure and consists of tailings relocation, grouting of decants pipes and under-drain pipes through the dam, grouting of drainage pipe left through the dam, surface water management, construction of a filter berm at the toe of the tailings dam, construction of a closure spillway, overflow channel construction, diversion channel upgrade and construction of field trials for engineered covers. Decommissioning and closure of waste rock dumps included re-sloping and re-vegetation. The paper discusses the challenges and opportunities experienced through the implementation of the closure plan together with potential avenues to generate funds to cover post closure liabilities. Finally, the paper gives a summary of the lessons learned.
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Attribution-NonCommercial-NoDerivatives 4.0 International