Laserfiche WebLink
i <br /> i <br /> 1 <br />' Ground Water Drawdown Test Calculations <br /> JIMCQ TRUCK PLAZA <br />' 22502 South Highway 99, Ripon, California <br />' Assumptions <br /> • A constant ground water pumping rate of 6 GPM for tests conducted in June 2002 <br /> • Well EW-1 is screened entirely through the upper water table of 21 feet from16 to 36 feet <br />' 0 Homogenous ground water aquifer characteristics at observation wells MW-1 through <br /> MW-9 <br /> • The Distance-Drawdown Method was used to calculate transmissivrty (T) and storativity <br />' (S) and hydraulic conductivity (K) utilizing draw-down veI sus distance (feet) on semi- <br /> loganthnuc paper for each well location <br /> • Equations <br /> T = 70Q/ds S = Tt/640 (ro)2 K= T/b <br /> Where <br />'. K= hydraulic conductivity <br /> T =transrnissrnty <br /> S = storativity <br />' Q = constant ground water pumping rate = 6.0. GPM. <br /> As = draw-down per 1-loganthrruc cycle (Appendix D) = 0.42 ft. <br /> t =time of pump test (Appendix C) = 2,880 minutes <br />' ro = intercept of best fit lure with the distance axis (Appendix D) = 160 feet <br /> b = aquifer thickness 15 feet (semi penetrated or exposed screen length) <br />' 14 June 2002 <br /> T = 70 (6 gpm) / 0 42 feet = 1000 feet2 /day or <br />' 1,000 feet'/day (1 gal day/ft/0 134 feet2 /day) = 7,462 gal day/feet <br /> S = 1,00 feet2/day(2880 minutes) /640 (160 feet)' = 0 175 <br />' K= 7,462 al da /feet / 15 feet = 497 5 feet/da <br /> g Y Y <br />' K=497 5 feet/day(1 cm/sec/283 5 feet/day) = 0.175 cm/sec <br /> Advanced GeoEnvironmental,Inc <br />