AWWA ACE54519

In order to preserve fresh groundwater in the Hueco Bolson Aquifer, and manage wellfield operations, El Paso Water Utilities (EPWU) of El Paso, Texas, has developed several groundwater models. The most recent model, which includes a flow model (MODFLOW) and a solute transport model (MT3D), developed by the U.S. Geological Survey was designed to address the impact of groundwater pumping on the Hueco Bolson. Authors proposed several strategies to extend the useful life of the aquifer based on modeling results. In this paper, two strategies will be discussed in detail. The first strategy is to develop a set of goals, or guidelines, to form the basis to optimize wellfield operations. Based on the modeling results, several water level depression cones were identified. Authors prepared a priority list for wellfield operations to ensure that drawdowns due to well pumping in the aquifer can be distributed evenly, water deterioration rates can be reduced, and marginal water can be better utilized by blending it with higher quality water. The second strategy is to use artificial recharge and possibly interception trenches to prevent further intrusion of brackish water into fresh water zones, and thereby preserve the fresh water in the aquifer. At the same time, marginal, brackish water can be fully utilized by blending it with fresh groundwater, and by desalination treatment at new desalination plants. Includes 9 references, table, figures.