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Rising/Falling Head Testing <br /> Procedure <br /> In rising falling head tests (slug tests), the static groundwater elevation of an aquifer, at <br /> the location of a well, is either increased or decreased "instantaneously" by introducing <br />' or removing a known volume of water into a well The total change in the groundwater <br /> elevation is recorded and the recovery of groundwater to static elevation is recorded at <br /> predetermined time intervals The equipment used in the slug test consisted of a <br /> I5-foot-long, 3-inch-diameter PVC pipe, sealed at both ends and filled with clean sand <br /> Prior to dropping the slug into the well, a pressure transducer was placed in the well and <br /> connected to a single-channel datalogger which recorded the changes in water level at <br /> predetermined time intervals. Prior to the slug test, all equipment was cleaned either with <br /> steam or a tnsodium phosphate solution to prevent contaminants from entering <br /> groundwater <br /> Data Analysis <br /> iAssumptions and site-specific conditions used in the analysis of this data include the <br /> following <br /> • Partial penetration of the wells <br /> • Saturated thickness is equal to the wetted screen length <br /> • Well casing diameter is 4 inches <br /> Well diameter is 10 25 inches <br /> • Water table (unconfined) aquifer <br />' Screen length is 20 feet <br /> • Static height of water in well is 12 feet <br /> • The top elevation of the screened interval in the well is higher than the static <br />' groundwater elevation <br /> The above assumptions are based on soil boring and monitoring well logs, groundwater <br /> elevation data, and field observations Because of the site conditions and monitoring well <br /> construction, only the data collected during the rising head tests was analyzed. The <br /> method used to analyze the data was the Bouwer and Rice slug test method for <br />' unconfined aquifers (Bouwer, et al., 1976) To facilitate the analysis of the collected field <br /> data, a curve matching computer program entitled "Agtesoly" (Geraghty and Miller, 1989) <br /> was used Rising head test in MW-4 began at time 18 34 20 50 and MW-7 at time <br />' 17 45 50 50 <br /> I <br />