Permitting / Injury Issues
Energy Fuels Sheep Mountain Project:
As part of the permitting process, the proposed open pit uranium mine in Fremont County, Wyoming had to demonstrate that it would not impact flows on Crooks Creek, a tributary to the Sweetwater River, which is then a tributary to the North Platte River. LWS developed a MODFLOW model of the pit to assess changes in ground water flow patterns due to dewatering and subsequent mining of the open pit, which was to be completed in phases. The results of the LWS modeling were used by Energy Fuels to obtain a mine permit from the Division of Environmental Quality.
Front Range Resources ASR Project:
LWS constructed both a steady-state and a transient numerical ground water model of the Lost Creek Basin on the Eastern Plains of Colorado, using MODFLOW. The purpose of the ground water model was to evaluate a proposed aquifer storage and recovery (ASR) project whereby water would be recharged into the Lost Creek alluvial aquifer using three separate rapid infiltration basins (RIBs) and the recharged water would subsequently be recovered through a series of 33 alluvial aquifer wells located down gradient of the RIBs. Parametric studies were conducted using the results from the MODFLOW model to demonstrate not only whether the water could be efficiently recovered by the down gradient wells but also whether the proposed operation prevents injury to other existing wells in the Basin.
Fort Knox Gold Project:
As part of the development of the gold project, a Tailing Storage Facility (TSF) had to be constructed on Fish Creek. The proposed TSF was not lined and, therefore, there was the potential for outflows either beneath the dam through fractured rock or around the abutments as previously frozen ground, i.e., permafrost, dissipated due to the energy in the tailings facility. LWS personnel modeled the ground water flow downstream of the TSF and then designed a series of monitoring/production wells that could be used to (a) monitor for any releases from the TSF and (b) if any releases were detected, pump the wells to create a hydraulic stall, delivering the pumped water back into the TSF. The results of the modeling and well design were provided to the regulatory agencies and the TSF was permitted.