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PUMP TEST PROCEEDURES <br /> MMODUCTION <br /> The presence of the two groundwater zones "A and B" and the construction of monitor <br /> wells MW 1 through NW5 screened across both zones, complicates the performance of a <br /> pump test at this site. <br /> Of major concern is the location of MW 1 in relation to RW1A and RW1B and the MW6 <br /> cluster, see Figure 3. <br /> With monitor wells completed across both zones, pumping from either a A or B zone <br /> well will cause flow up or down the cross zone wells (MWl through MW5) once the <br /> radius of influence has reached that cross zone well, possibly showing pumping influence <br /> m the non pumped zone <br /> ASSUMPTIONS_FROM LITHOLOGY AND GROUNDWATER <br /> MEASUREMENTS. <br /> { <br /> Both the A-Zone and the B-Zone are under confined conditions The groundwater head <br /> has come to an equilibrium state on-site because of the presence of the cross zone wells <br /> Further away from the site in MW6A and MW6B there is a difference of 0.02 feet <br /> between the pressure head in the two zones. Examination of the lithology of the two <br /> zones indicates that there should be a significant difference in the hydraulic conductivity <br /> (K) of the two zones A zone with its silty to clayey sands should have a much lower K <br /> than the B zone with its clean sands. This difference could be as much as two orders of <br /> magnitude <br /> The top of the A-Zone is at an elevation that a high pump rate combined with the lower <br /> expected K could cause the aquifer to pass from confined to unconfined conditions with <br /> the lowering of the groundwater head by approximately 3 feet <br /> PLAN FOR PUMP TEST. <br /> Because of the confined/semi-confined nature of the water bearing zones at this site, it is <br /> advisable to collect baseline groundwater head data pnor to performing the pump test. <br /> The zones being in a confined state,the potentiometric head will respond both to changes <br /> in the barometric pressure, tidal influences and surface loading on the adjacent ground <br /> surface. In order to help determine the possibility of these effects on the system, pressure <br /> transducers will be placed in MW6A and MW6B a week prior to the pump test. <br /> 26 Sanchez 2nd QM 2001 <br />