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%%� 1-.00 1" K L E I N F E L D E R <br /> B-2.10 Soil Boring Closure and Cutting Disposal <br /> Soil borings are closed immediately after the collection and logging of soil samples. Closure is <br /> accomplished by grouting the boring with a cement/bentonite slurry or as otherwise required. <br /> Drill cuttings will be placed in 55-gallon drums wrapped in plastic or spread around the boring <br /> and left on site for disposal by the site owner. If requested, Kleinfelder can coordinate disposal <br /> of soil and water after analytical results are available. <br /> B-3 GROUNDWATER WELL INSTALLATION <br /> B-3.1 Monitoring Well Construction <br /> Construction details for shallow groundwater monitoring wells are as follows: <br /> • The well casing are 2- or 4-inch inside diameter, flush threaded joint, schedule 40 <br /> PVC pipe. <br /> • The wells are constructed in 8- or 10-inch diameter borings. <br /> • Well screen sections are perforated with 0.010-or 0.020-inch factory-cut slots. <br /> • The wells are generally screened from 5 feet above to 15 feet below first <br /> groundwater. The screen length is reduced if an aquitard with a minimum <br /> thickness of 5 feet is encountered. If an apparent aquitard is encountered, the well <br /> is usually terminated 1 to 2 feet into the aquitard. Effort is made not to screen <br /> across two aquifers. If confined aquifer conditions or high vadose zone <br /> contamination are encountered, the well screen is usually not set above the depth <br /> of first encountered groundwater. Wells are usually not set in areas of suspected <br /> significant soil contamination. <br /> • The PVC pipe and end caps are steam cleaned prior to installation. <br /> • The annular space between the screen and the wall of the boring is backfilled with <br /> the appropriate clean sand to approximately 2 feet above the top of the perforated <br /> sections. Based on soil logs or a sieve test, modifications may be made regarding <br /> the size of sand to be used. Installation of the sand may require that the sand be <br /> tremmied, using clean water. <br /> • A 3- to 5-foot bentonite plug is placed above the sand pack to provide a seal <br /> against surface water infiltration and to reduce the potential for cement grout to <br /> infiltrate into the water. <br /> • The remaining annular space is filled to the surface with cement/bentonite grout. <br /> 44843.T04/ST04RI 121r Page B-4 <br /> Copyright 2004,Meinfelder,Inc. September 2,2004 <br />