Risk-based remedial planning for the abandoned Emerald Glacier Mill and Tailings Site Dickin, R.C.; Phibbs, J.; Rankin, M.; Sanborn, M.
The Emerald Glacier Mill and Tailings Site is an abandoned, base metal, ore processing site located on Crown Land approximately 80 km southwest of Houston BC that was prioritized for remedial action by the BC Crown Contaminated Sites Program (CCSP). The investigations, analysis and decisions required for developing an effective, risk based, remedial plan to return the site to a safe, healthy forest environment are described. Field investigations were conducted in a progressive manner to identify and quantify physical and chemical risks to human health and the environment and to develop remedial objectives. Detailed quantitative risk assessment was conducted to identify and prioritize the various exposure pathways that warranted mitigation.. Sustainability issues and conflicts with remedial action were identified, such as maintaining intact forest and riparian vegetation along the creek. A risk based remedial plan was developed to address the following objectives: i) Prevent physical erosion and off-site migration of the tailings as suspended sediments; ii) Mitigate or eliminate contaminant exposure pathways that confer a high risk for the Site, including: a. Human Health - Remediate/manage site contamination to a state where future traditional or recreational human use will not cause unacceptable health risks, with specific consideration for ingestion of site water and locally harvested game; and b. Environmental Protection - Remediate/manage site contamination to a state where residual contaminated soil poses acceptable or tolerable risks to ecological receptors such as mammals, birds, soil invertebrates and plants. The risk management that involved physical remediation included: a) containment and capping of the tailings; b) capping of the ore processing and mill area; and, c) decommissioning of a small water supply dam on the creek upstream of the tailings facility. Environmental contamination that was not subject to physical remediation, due to lesser and tolerable risk or sustainability conflicts, included metals in groundwater, stream sediments and soil located in high value forest areas.
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Attribution-NonCommercial-NoDerivs 2.5 Canada