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!w"LARAM I DE <br /> Statement of Qualifications z:='�Environmental,LLC <br /> extensive database of groundwater elevations, a 30-foot change in groundwater <br /> elevation across the fault zone, and measured TCE concentrations at monitoring wells <br /> throughout the site. <br /> The model was used to demonstrate that natural attenuation would control off-site <br /> transport at a residual TCE concentration much higher than the default state standard. <br /> Results of the modeling also indicated that an off-site source was likely responsible for <br /> a portion of the on-site groundwater contamination. The model results were used to <br /> support a site-specific remedial action goal of 500 µg/L for TCE that was eventually <br /> accepted by the state regulatory agency. <br /> Evaluation of Brine Migration in Groundwater, Wyoming: Brine migration from a tailings <br /> pond at a trona mine and processing facility threatened a nearby river. Discharge of <br /> salts to the river was prohibited by an interstate water-quality compact. The project <br /> objective was to identify feasible methods to halt the brine migration before it reached <br /> the river. <br /> As the project hydrogeologist, Walter developed numerical models of groundwater flow <br /> and contaminant transport to assess when the river would be impacted by brines from <br /> the tailings pond as well as the mass flux to the river. Complexities in the numerical <br /> evaluation included consideration of groundwater flow in a stratified, multi-aquifer <br /> system with leaky confining layers and interactions between surface-water bodies such <br /> as storm-water detention ponds and the river with the underlying aquifer. An automatic <br /> parameter-estimation code was used to assist with model calibration and evaluate <br /> alternative conceptual models of groundwater flow in the complex system. <br /> After calibrating the groundwater flow model to existing groundwater and surface-water <br /> elevation data, Walter used the output to provide the velocity field for a particle-tracking <br /> model. The particle-tracking model was calibrated using groundwater quality data from <br /> the existing multi-level monitoring well network. The calibrated particle-tracking model <br /> was then used to predict the future position of the brine plume under alternative <br /> remedial scenarios. A groundwater interception system based on an existing <br /> interception trench was conceptualized to halt the brine migration before measurable <br /> impacts would occur on the river. <br /> Environmental Permitting <br /> Waste-Rock Impoundment Impact Evaluation, Washington: Walter acted as the project <br /> hydrologist for this evaluation in support of permit applications. The potential impacts <br /> of planned waste rock impoundments on the surface-water and groundwater systems <br /> were evaluated. The evaluation included assessment of the abstraction of rainfall and <br /> snowmelt due to the placement of the waste-rock impoundments. The potential <br /> changes in streaimflow and groundwater levels were quantified and reports submitted to <br /> the client, state, and federal regulatory agencies. <br /> Environmental Data Management <br /> Water Resource Assessment, Califomia and Nevada: Walter acted as project hydrologist <br /> and project manager for a water resource assessment in the upper Carson River Basin <br /> August 2004 Page 5 of 7 <br />