In response to the contamination problem C.U.R.E. has developed a comprehensive remediation process that is technically innovative, cost-effective, within the parameters defined by the local community, and in compliance with all applicable regulations. To address the critical issues and constraints associated with the mine tailings pile, we are proposing a multi-facet remediation process. Our design incorporates technologies to remediate the contaminated groundwater and prevent additional surface water contamination. The main components of the design (Figure 1) are a permeable reactive wall down-gradient of the tailings pile, a horizontal reactive layer in the pile, a surface runoff collection system, and a concrete trench for the stream flowing adjacent to the pile. The chosen remediation process (Figure 1) satisfies all relevant requirements and provides a practical solution.

The down-gradient treatment wall, composed of limestone and activated alumina, intercepts the groundwater plume and ensures regulatory compliance by removing metals through precipitation and adsorption. The combination of these two mechanisms helps address the uncertainty factor associated with the non-homogeneity of the tailing pile. To avoid long-term expense associated with regular replacement of worn out reactive media, we have designed a horizontal reactive layer containing potash (K₂CO₃) and wood-chips to neutralize the tailings and create an anaerobic environment in the pile. Eliminating the available oxygen in the pile stops the acid-generating and metabolic activity of microorganisms, such as Thiobacillus ferrooxidans [2]. We will be using biosolids to create such an environment. Direct contact of the adjacent streambed with the tailing pile will be prevented by diverting the stream through a concrete channel for the entire length of the pile.