Multi-observation well aquifer test case study: is recovery coincident with the cessation of pumping?
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Due to increases in water demand, the City of Kenedy, TX, USA must expand their small drinking water supply in the Gulf Coast aquifer system. Groundwater wells owned by the City of Kenedy, Karnes County, TX were examined to estimate properties for the Jasper aquifer. Conditions of four wells were assessed, after which two wells were rehabilitated and used as pumping wells in aquifer tests. Aquifer tests show that recovery in observation wells was not coincident with the cessation of pumping. Post-pumping data were selectively excluded so that only recovery data were used for analyses. Transmissivity for the Jasper aquifer ranges from 102 to 242 m2 d−1, and storativity ranges from 6.9E−05 to 3.3E−04. Transmissivity computed from recovery data was approximately 25 % higher than transmissivity computed from time-drawdown data. Field measured specific capacities and drawdowns were compared to theoretical specific capacities and drawdowns to calculate pumping well efficiencies in the range of 52.2–99.4 %. This study indicates that water demand for the City of Kenedy could be met by incorporating the tested wells into the water supply system. Future studies should be designed to estimate groundwater recharge rates and a complete water balance for computing a sustainable maximum annual yield.
KeywordsJasper aquifer Well rehabilitation Aquifer testing Sustainability USA
We acknowledge the City of Kenedy for funding this research project, the Center for Water Research (CWR) at The University of Texas at San Antonio (UTSA) for providing student and administrative support, Alsay Water Well Service (Alsay) for well rehabilitation services, Veolia Water for assisting with site access and water infrastructure operation, and GeoCam for partnering on borehole camera surveys. The authors acknowledge the time taken by various peer reviewers and thank them for their thoughtful comments.
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