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APPENDIX E -- SLUG TEST CALCULATIONS <br /> CALCULATION OF HYDRAULIC CONDUCTIVITY <br /> ' First groundwater at the Art & Artists site occurs in a downward-coarsening sand body that <br /> is present at approNimately 60 feet below ground surface. This sand body is considered to <br /> be an unconfined water-table aquifer. Model 18 of Dawson and Istok (1991) was used to <br /> ' calculate the hydraulic conductivity of this aquifer. In this model, the hydraulic conductivity <br /> can be computed using the following equation: <br /> ' K = r z In rw), where <br /> 2(1-d)tL) <br /> ' r,, is the effective radius of the well casing <br /> rw is the borehole radius <br /> R is the radius of influence of the well <br />' 1 is the distance from the static water table to the bottom of the casing <br /> d is the distance from the static water table to the top of the screen interval <br /> tL is the time lag ' <br /> ' Furthermore r.2 = riz x 1 - + q5r,,,21 where <br /> r; is the inside radius of the well screen <br /> ro is the outside radius of filter material <br />' 0 is the porosity <br /> and ln(R/rw) = 1.1 + A + B(ln[m-l}1rwj}`1 <br /> ln(1/rw} (1-d)/rw where <br /> m is the thickness of the aquifer <br /> A and B are empirically determined dimensionless coefficients that are functions of <br /> 1-d/rw <br />' and tL is determined from the graph of HJH. vs. T or calculated according to: <br /> tL = tl <br />' ln(H.,,,/H.)1 - ln(HJH.)z <br /> Calculations for each test are given on the following pages. <br /> A&A Pte-23.90.x7 <br /> 1 <br />