ARCHIVED REPORTS XR0006027 - Laserfiche WebLink

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1 Rising/ Falling Head Testing Procedure ' In rising/fallinghead tests (slug test the static groundwater elevation of an aquifer, at the � 9 ) location of a well, is either increased or decreased instantaneously by introducing or ' removing a known volume of water into a well The total change in the groundwater elevation is recorded, and the recovery of groundwater to static elevation is recorded at predetermined time intervals The equipment used in the slug test consisted of a 5-foot-long, 3-inch-diameter PVC pipe, sealed at both ends and filled with clean sand Prior to dropping the slug into the well a pressure transducer was placed in the well and connected to a single channel data logger which recorded the changes in water level at pre determined time intervals Prior to the slug test all equipment was cleaned either with steam or a trisodium phosphate solution to prevent contaminants from entering ' groundwater Data analysis ' Assumptions and site specific conditions used in the analysis of this data include the following ' • Partial penetration of the wells • Saturated thickness is equal to the wetted screen length • Well casing diameter is 4-inches • Well diameter is 10 25 inches • Water table (unconfined) aquifer ' • Screen length is 20 feet • Static height of water in well is 12 feet The top elevation of the screened interval in the well is higher than the static ' groundwater elevation The above assumptions are based on soil boring and monitoring well logs, groundwater ' elevation data, and field observations Because of the site conditions and monitoring well construction only the data collected during the rising head tests was analyzed The method used to analyze the data was the Bouwer and Rice slug test method for ' unconfined aquifers (Bouwer, et al 1976 ) To facilitate the analysis of the collected field data, a curve matching computer program entitled Aqtesolv (Geraghty and Miller, 1989) ' was used t