2008-03-03_REVISION - M1988112 (21)

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Objection to BMRI's AM-03 Page 14 of 23 February 22, 2008 an analysis of ground water flow and a fate and transport of constituents in that ground water flow. Since there is a question concerning fluoride concentrations in the West Pit ground water and its potential affect downgradient of the proposed irrigation pivots on the Salazar Ranch, a methodology to make these predictions was necessary. The MODFLOW model was chosen because the State Engineer's Office has recently completed the Rio Grande Decision. Support System ("RGDSS°), which includes the RGDSS ground water flow model constructed using MOOFLOW. Therefore, many of the parameters for the model were obtained from an existing regional model. Since fluoride is the only constituent in the West Pit water that is predicted to reach the local ground water table at a concentration above background as a result of using West Pit water for irrigation at the Salazar Ranch, the MODFLOW and MT3DMS modeling focused on predicting ground water and mass flow of fluoride toward the southern property boundary well SLM-2 since continued irrigation of the Salazar Ranch irrigation pivots with West Pit water will not adversely affect any current or reasonable foreseeable future of ground water between the pivots and the SLM-2 well (since Battle Mountain Resources, Inc., controls use through this reach), fluoride concentrations. were predicted at the SLM-2 well, based on the steady-state location and amount of fluoride entering the aquifer from proposed irrigation practices. The process for this evaluation was to develop a conceptual model of ground water flow, including aquifer parameters and boundary conditions which provide a representative simulation of actual ground water flow conditions beneath the Salazar Ranch, specifically between the points of irrigation at the pivots and the SLM-2 well. This process also included the development of a conceptual model for solute transport related to model inputs being made relative to the fluoride mass input to the ground water aquifer and the absorptive and advective conditions relating to the movement of this solute along the.ground water gradient. Once these models were conceptualized, the models were then built, tested, and run for the expected scenario under