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Appendix C Slog gest Procedures C.2 ANALYTICAL METHODS AQTESOLV for WindowsTM was utilized for the analysis of the slug test data The following is a discussion of the two analytical solutions used to evaluate the slug test data collected during field activities Results of the analysis are summarized in Table 5-3, and the data plots are attached at the end of this appendix Gomer-Rice (1976) The Bouwer and Rice (1976) solution, based on Thiem's equation, incorporates an empirical relationship describing the water-level response in an unconfined aquifer resulting from the instantaneous injection or withdrawal of water from a well The Bouwer-Rice (1976) solution recommends computing an equivalent casing radius (r,:) to correct for the porosity of the filter material when the change in water level occurs witlun the filter material In addition, Zlotnik (1994) advises the use of an equivalent well-bore radius if the aquifer is anisotropic in the vertical plane Application of the Bouwer-Rice (1976) method to estimating the hydraulic conductivity of an unconfined aquifer assumes that within the area of the test the aquifer is infinite in areal extent, is homogeneous and isotropic and uniform in thickness Other assumptions and conditions include that the water table is (nearly) horizontal, the piezometric head in the well is changed instantaneously, the drawdown around the well is negligible, there is no flow above the water table, the linear and non-linear well losses are negligible, the well either partially or fully penetrates the saturated thickness of the aquifer, the well diameter is finite and the flow is steady state Details of this method are described on the following pages Cooper-Bredehoeft-Papadopulos (CBP) (1967) Cooper et al (1967) derived an analytical solution describing the water-level response due to the instantaneous injection or withdrawal of water from a well in a confined aquifer By matching type curves of the Coo er-Bredehoeft-Pa ado ulos slug test solution to data plotted on semi-logarithmic axes, it is possible to estimate T and S for a confined aquifer Application of the CBP method to estimating the transmissivity and storativity of a confined aquifer assumes that within the area of the test the aquifer is infinite in areal extent. is homogeneous and isotropic, and uniform in thickness Other assumptions and conditions include that the water table is (nearly) horizontal, the piezometric head in the well is changed T 11999141-04010004 stocktanWugtestAppc doc123-NOV 99x8840173X8NA C-7