Laserfiche WebLink
' Ground Water Drawdown Test Calculations <br /> J1MCO 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 froml6 to 36 feet <br /> t Homogenous ground water aquifer characteristics at observation wells MW-1 through <br /> MW-9 <br /> • The Distance-Drawdown Method was used to calculate transrnussivity (T) and storativity <br /> (S) and hydraulic conductivity (K) utilizing draw-down versus distance (feet) on serni- <br /> loganthnuc paper for each well location <br />' Equations <br />' T = 70Q/ds S = Tt/640 (r.)2K= T/b <br /> Where <br /> 10K <br /> =hydraulic conductivity <br /> T =transmissivity <br /> S = storativity <br /> Q = constant ground water pumping rate = 6.0. GPM. <br /> As = draw-down per 1-loganthmlc cycle (Appendix D) = 0.42 ft. <br /> t =time of pump test (Appendix C) = 2,880 minutes <br /> ro = intercept of best fit line with the distance axis (Appendix D) = 160 feet <br /> b= aquifer thickness 15 feet (semi penetrated or exposed screen length) <br /> t14 June 2002 <br /> T = 70 (6 gpm) / 0 42 feet = 1000 feet' /day or <br />' 1,000 feet' /day (1 gal day/ft/0 134 feet'/day) — 7,462 gal day/feet <br /> S = 1,00 feet' /day(2880 minutes) /640 (160 feet)2 = 0 175 <br /> — 15 feet =497 5 feet/da <br /> K— 7,462 gal day/feet / e y <br />' K= 497 S feet/day(1 cm/sec/283 5 feet/day) = 0 175 cm/sec <br />' Advanced GeoEuvtronmcntal,Inc <br />