Laserfiche WebLink
Where Q is equal to the pumping rate in cubic feet per day, B is equal to the aquifer thickness in <br /> • feet, and U is equal to the groundwater flow velocity in feet per day Groundwater flow velocity <br /> is equal to the hydraulic conductivity multiplied by the potentiometric surface gradient and then <br /> divided by the porosity <br /> The distance between dividing stream lines far upstream from the extraction well is represented <br /> by the equation <br /> —Q— <br /> BU <br /> The equation for the distance from the extraction well to the zone of stagnation (downgradient <br /> extent of capture) is represented by the equation <br /> Q._._ <br /> 2 7rBU <br /> Where a is PI winch is equal to approximately 3 14159 <br /> • <br /> Aspects of the development and/or use of the above referenced equations is also presented in <br /> Keely (1984), Keely and Tsang (1983), and McElwee (1991), as well as Javandel and Tsang <br /> (1986) and Grubb(1993) <br /> 52 C API'URE ZONE PARAMETERS FOR WELL E W-1 <br /> The sustainable pumping rate from well EW-1 is assumed to be 7 gallons per minute, resulting in <br /> a Q in the above equations of 1,347 5 Ft3/day Lower pumping rates would result in <br /> proportionally narrower capture zones, higher wider <br /> The aquifer thickness, parameter B, will be assumed to be equivalent to the saturated screened <br /> interval in well EW-1, i e 12 58 feet The thickness will vary with the seasonal fluctuations in <br /> %vater level and with dewatering effects, as well as with stratigraphic variations <br /> fhe groundwater flow velocity, parameter U, is equal to the hydraulic conductivity multiplied by <br /> the potentiometric surface gradient and then divided by the porosity <br /> H,,OGEOL A GROUNDWATER CONSULTANCY <br />