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f1 Treadwell&Wlo 4.1 Sample Collection Between 15 and 24 January, six borings (CS13-1 through CSB-6) were advanced and soil and groundwater samples were collected for laboratory analyses Figure 2 shows the boring locations A boring permit was obtained from the SJCEHD, and an SJCEHD inspector visited the Site Prior to conducting the subsurface investigations, we notified Underground Services Alert and contracted with a private utility locator to clear proposed boring locations for potential underground utilities All soil, groundwater and decontamination water generated during this scope of work were stored on site in drums pending analytical results All borings were closed by pressure grouting in accordance with San Joaquin County requirements Continuous soil cores were collected from each boring using a direct push method with a cased hole Precision Sampling Inc was the drilling contractor and used their proprietary direct push Enviro-Core sampling equipment The Enviro-Core system consists of a 3 5-inch diameter drive casing and an inner sample barrel Continuous soil cores are collected inside the sample barrel After being advanced approximately 3 feet, the full sample barrel is retrieved while the drive casing is left in place to prevent the hole from collapsing The direct push method produces minimal cuttings at the surface during the sampling process and allows grout to be pumped through the casing to close the borings The borings were advanced from 31 to 37 5 bgs, except for Boring CSB-6, which encountered concrete refusal in two attempts at 4 5 and 8 feet bgs To facilitate grab groundwater sample collection, the boring casing was pulled up to approximately just above the groundwater elevation, and temporary one-inch diameter slotted PVC casing was placed into the borings Groundwater grab samples were collected using a dedicated disposable polyethylene bailer 4 ' 25971013 DGD 12 April 2004 I