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• Aquifer characteristics of the underburden were determined via slug testing. A slug test was <br />performed in well MW~U, and recovery of the well was monitored for approximately 7 hours. <br />Within this time period no recovery was noted. This indicates an extremely low hydraulic <br />conductivity for the underburden. Estimated hydraulic conductivity would be on the order of 10-Z <br />ft/day. Storativiry would be estimated as lU' to 10~. A second well MW-6U was also tested. <br />This well has a sound of either cascading water or gas. According to the slug test results of this <br />well, this material would have a hydraulic conductivity 5 to 7 orders of magnitude higher than any <br />of the other consolidated rock wells onsite. This data indicates either the interception of fracture <br />zone, or the releasing of gas through the well. This data would not be considered as representative <br />of the underburden zone. <br />Estimated hydraulic conductivity is from the regional data provided by Howard. Examining the <br />values of hydraulic conductivity, this value is estimated as 0.0408 ft/day. This value can be <br />translated to uansmissivity (T) by the equation T = Kb, where T is uansmissivity, K is hydraulic <br />conductivity, and b is the aquifer thickness. Therefore: <br />T=Kb <br />T = (0.0408 ft/day)(1000 ft) <br />T = 40.8 ftr/day or 305 gld/ft (estimated for entire thickness) <br />• The potential pumping rate from a fully penetrating well can be estimated from the equation <br />Q=Ts/2000. (derived from Fetter, 1980). In this calculation Q is the flow rate, T is the <br />uansmissivity (determined from the hydraulic conductivity T=Kb), s the available drawdown, and <br />2000 is a constant (accounts for conversion of T in g/d/ft). Therefore: <br />Q = 305 g/d/ft [1000 ft (formation thickness)]/2000 <br />Q = 152 gpm (for regional data) <br />Generally, the rate of evacuation for the wells during the sampling events is estimated as 1.0 gpm. <br />This value and the potential pumping rate for the well (determined above utilizing regional data) <br />compare favorably; therefore the range of the transmissivity in this zone is probably 305 g/d/ft. <br />Groundwater seepage velocity (vs) can be determined from the gradient (dh/dl, or I), effective <br />porosity (tt~, and hydraulic conductivity (K). Seepage velocity represents the rate at which water <br />actually moves through the pore spaces. The relationship v,=Ki/n~, is utilized to determine this <br />value (Fetter, 1980). From the above analyses: <br />K = 0.98 ft/day (for regional values) <br />I = 0.008 ft/ft <br />rk=10% <br />CJ <br />PERMff.a]S~Dr¢mbu 20, 1996 2.04-20 <br />