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_. ----a$— ZZ,CLEARWATER <br /> • G R O U P, I ISI C <br /> If it is determined that the test was performed under confined aquifer <br /> conditions and enough time has elapsed for steady-state conditions to have <br /> been met (as defined in the literature), the Jacob distance-drawdown and <br /> time-drawdown methods (Cooper & Jacob, 1946) will generally be applied to <br /> evaluate storativity and transmissivity Alternatively, the Theis curve- <br /> fitting method (Theis, 1935) may be employed if steady-state conditions were <br /> not reached. In leaky aquifers, the Hantush method (Hantush, 1956) will <br /> generally be used <br /> The capture zone will also be determined using the transmissivity values <br /> obtained through the evaluation and following the method initially outlined <br /> by Janvandel and Tsang (1986). The data will then be used to determine the j <br /> construction and design specifications of the proposed system, based on the <br /> requirements of the system conceptual design (migration control, dewatering, <br /> plume capture) <br /> It must be g <br /> recognized that even using theoretical models for the data <br /> g <br /> evaluation, some judgement will be necessary in conducting the analyses and <br /> applying the calculated parameters to the system design Different types of <br /> aquifers may have similar drawdown or response behaviors, and this must be <br /> accounted for A complete explanation of the method used and the reasoning <br /> behind the choice of method and an analysis of the results will be presented <br /> with the data evaluation <br /> REFERENCES <br /> Boulton, N S (1954) The drawdown of the water table under nonsteady <br /> conditions near a pumped well in an unconfined formation Inst Civil <br /> Engrs , Proc , Vol. 3, p 564-579 <br /> Cooper, H H & Jacob, C E (1946) A generalized graphical method for <br /> evaluating formation constants and summarizing well field history Am <br /> Geophys Union Trans Vol. 27, p 526-534. <br /> Creative Scientific Applications (1992-1994) The Aquifer Test Toolbox, <br /> Aquifer Test Worksheets for Hydrogeologists and Engineers Ver 10 , <br /> Wellsville, Penn <br /> Hantush, M.S (1956) Analysis of data from pumping tests in leaky aquifers <br /> J Geophys Res Vol. 64, p 1043-1052 <br /> Constant-Discharge Aquifer Test Page 4 of 5 December 16,1994 <br />