Leviathan Mine Site

SSP&A was initially retained in 2010 to provide expert review and evaluation of hydrologic, hydrogeologic, and geochemical conditions at the former Leviathan Mine Site in Alpine County, California, and to assess the sources of impacts of mining-related residues on groundwater and surface water.

SSP&A reviewed geochemical data to evaluate the remedial design implemented at the Site. A review of surface water geochemical fluxes indicated that significant groundwater fluxes, which were not accounted for in the initial remedial design, were contributing to surface water. An evaluation and quantification of the sources of loading to Leviathan Creek was required to fully understand the effectiveness of abatement measures to achieve loading reductions.

Using the PHREEQC geochemical modeling software, SSP&A determined chemical speciation of mining-impacted water and surface water. This analysis found that chemical speciation varied depending on flow conditions and the release of treated and untreated water to Leviathan Creek.

SSP&A was subsequently tasked with managing a non-litigation related matter starting in 2019 to develop a comprehensive understanding of surface water and groundwater conditions at the Site to support the development and selection of appropriate long-term remedial components for the Site to cost-effectively minimize the releases of acidic groundwater to surface water and minimizes the migration of acidic groundwater.