Laserfiche WebLink
GecHydrologic Consultants, Inc <br /> 1 <br /> . increased steadily throughout the 12-hour pumping test, therefore observation well data <br />' could not be used to determine aquifer characteristics for the Site <br /> Transmrssivity, storativlty, and hydraulic conductivity were then calculated using the <br />' following formulas <br /> T = 35Q/ds <br /> K= T/b <br />' S = Tto/640r2 <br /> Where <br />' T = transmissivity (W/day) <br /> K = hydraulic conductivity (ft/day) <br />' S = storativlty (dimensionless) <br /> Q = pumping rate (gpm) <br /> ds = change in drawdown during one log cycle (ft) <br />' b = thickness of aquifer (ft) <br /> to = Intercept of line with x-axis (minutes) <br /> r = distance of observation well from pumping well (ft) <br /> • The velocity of groundwater is determined by the formula <br />' v = Ki/n, <br /> Where <br />' v = velocity (ft/day) <br /> i = groundwater gradient (0 0039, February 9, 2005) <br />' ne = effective porosity(assumed 30% for silt/sand) <br /> The downgradient stagnation point (or distance downgradient that water will be captured <br />' by the pumping well) estimated from the transmissivity is determined by the formula <br /> R = Q/27rTi <br />' Where <br />' R = downgradient stagnation point <br /> Q = pump rate (gallons/day) <br /> T = transmissivity (gallons/day/foot) <br /> 1 <br />' TOC 171 Plat Study Page 18 <br />