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where: R = effective radial distance over which the head <br /> difference is dissipated, <br /> rW = radial distance between well center and <br /> undisturbed aquifer, <br /> L = height of perforated section of well through <br /> which ground water enters, <br /> Yo = difference in head elevation at time zero, <br /> Yt = difference in head elevation at time t, and <br /> t = time since Yo. <br /> When the observed water elevation data are plotted against <br /> time ;t) on a semi-logarithmic paper (t on the arithmetic <br /> scale) , the data points should produce a straight 'Ane. <br /> The data begins to deviate from the straight line <br /> relationship at a small change in water table head. The <br /> ' straight-line portion of the curve should be used to <br /> evaluate 1/t•ln (YO/Y.t) and calculate K. The results of <br /> this method are generally considered appropriate as a <br /> N means of estimating the hydraulic conductivity within an <br /> }- order of magnitude (Thompson, 1987) . <br /> Field Test,PrQg%jMre.9 <br /> Prior to any aquifer test, depth to water was measured in all <br /> �.. eight monitoring wells located on- and offsite. Since a <br /> permit to discharge the pumped ground water into the city <br /> sewer was denied, Armour Petroleum, a certified hazardous. <br /> waste hauler, was contracted to pump and haul the pumped <br /> jz ground water. <br /> Icy <br /> A pump test was first performed at the site. The time which <br /> : ground water level measurements and pumping began was <br /> considered to be time zero. The pumped well was MW-3 while <br /> the drawdown effects were measured on MW-4. The drawdown in <br /> the water table in MW-4 was measured by an electric sounder <br /> I at intervals of one minute. The pump test was terminated <br /> E upon filling up the capacity of the tank in the truck. <br /> When the depth to water levels stabilized after the pump <br /> ,. test, a slug test was then performed on MW-3 and MW-4 by <br /> introducing clean water. The subsequent drop in water level <br /> over time was recorded in the same manner as the pump test. <br /> The slug test was terminated when the depth to water readings <br /> reached the original depth to water reading before the test <br /> j- <br /> started. <br /> L <br /> -- ---- ------- <br /> 9 <br />