Remedial options evaluation for the abandoned Atlin Ruffner mine

Groundwater and surface water are important natural resources that require protection during all phases of the mine life cycle. The ability of a remedial solution to achieve water quality criteria is a key consideration during the development and selection of remedial alternatives. Characterization of hydrology and hydrogeology is required to inform technical aspects of remedial planning. This case study presents the remedial options evaluation undertaken for the remote abandoned Atlin Ruffner Mill and Tailings Site in a complex geological setting. Groundwater downgradient of the Former Tailings Pond was affected by acid rock drainage and metal leaching, with low pH and elevated concentrations of sulphate, fluoride, arsenic, cadmium and zinc. Six remedial options capable of removing and/or cutting off the exposure pathways of contaminant concern were developed and evaluated: off-site disposal, in-situ isolation, on-site landfill disposal, in-situ soil stabilization, in-situ amendment, and permeable reactive barrier. A water balance and water quality model was developed to quantitatively predict water quality in the receiving environment for each remedial option. In-situ isolation was selected as the preferred remedial option for the Site, which included a piped surface water diversion, two interceptor trenches and a bituminous geomembrane liner over the Former Tailings Pond. The Phase 2 Remedial Works have been completed, resulting in desaturation of the tailings, and improved downgradient groundwater quality.Non UBCUnreviewedOthe