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GENESIS ENGINEERING &REDEVELOPMENT <br /> 7. Vertical Gradients <br /> Measure the vertical gradients between the upper and deeper water bearing units; <br /> advance a CPT boring to a depth of 60 feet bgs to determine the depth and thickness <br /> of the water bearing units below the Site; install a cluster of three piezometer wells to <br /> determine the vertical gradient between the upper two or three water bearing units; <br /> depending on depth and thickness of the units. <br /> 2.1.1 Native Soil Sampling <br /> Twenty-four direct push borings (DP-1 through DP-24) will be advanced to the groundwater <br /> interface to obtain soil samples for laboratory chemical analyses. The proposed sampling <br /> locations are shown on Figure B-1. One composite native soil sample will be collected from <br /> each boring. The sample will be collected as a four-foot section of core taken from the <br /> approximate center of the distance between the bottom of the drilling mud to the vadose zone <br /> immediately above the shallow water bearing unit. In addition, at six of the boring locations, the <br /> boring will be advanced into the water bearing unit and a soil sample collected from the water <br /> bearing unit for the purpose of obtaining sieve analyses. Soil sampling procedures are discussed <br /> in Section 3.1. <br /> 2.1.2 Drilling Mud Sampling <br /> The same 24 borings used to collect the native soil samples will be used to collect the drilling <br /> mud samples (Figure B-1). One composite drilling mud sample will be collected from each <br /> boring. The sample will be collected as a four-foot section of core taken from the approximate <br /> center of the distance between the top and bottom of the drilling mud. Soil sampling procedures <br /> are discussed in Section 3.1. <br /> 2.1.3 Cone Penetration Testing <br /> A CPT boring, using direct push technology,will be advanced to assess subsurface lithology and <br /> determine the depth and thickness of the upper two or three water bearing units below the Site. <br /> The CPT logs will identify changes in soil lithology for the purpose of selecting the appropriate <br /> screening depths for the piezometer wells and the monitoring wells. <br /> 2.1.4 Groundwater Sampling <br /> Three of the direct push borings being used to investigate the native soil beneath the drilling mud <br /> will be advanced into the upper water bearing unit and grab groundwater samples will be <br /> collected for laboratory chemical analyses. Proposed sampling locations are shown on Figure B- <br /> Sampling and Analysis Plan 3 of 24 <br /> DePaoli Property <br /> November 14,2007 <br />