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` kJ The GeoProbe collected continuous cores of soil in each Borehole. The sampler was retrieved after each sample push and dissembled, and soil Sample intervals retained for chemical. analysis were out from the line'rs at the desired depths. leach soil sample retained for chemical analysis was sealed with Teflon paper or fail and plastic endcaps, labeled, logged onto chain-of=custody forms and place in a chilled ice chest on crushed ice for transport to the laboratory. The GtoProbe borcholes were continuously logged using the Unified Soil Classification System under the supervision of a. professional. geologist.' Additional lithologic information was collected as needed to describe the subsurface geology. Soil. samples were field screened with a portable photoionization detector (PID) for indications of petroleum fuel hydrocarbon vapor and visually checked for staining. 3.1 _Field Methods-Groundwater Sampling from Open GeoProbe Boreholes Groundwater samples were collected from each borehole. A brief summary of the sampling procedure follows_ The boreholes were advanced into the aquifer and to the desired depth.. Each borehole was advanced into the desired aquifer depth interval and temporarily cased for sampling, or a HydroPunch sampler device was used for some sampling. Two additional boles were advanced at B-10 and 13-:12 to collect "deep„ groundwater samples following a field discussion with the SJC[EHD representative. Two groundwater-sampling procedures were used. Boreboles were sampled with pre-cleaned tubing and check-ball valve to bail a sample to the surface. A :HydroPunch tool was used to collect the two" deep' groundwater samples. The HydroPunch tool is advanced to the depth and then opened by pulling the outer sleeve to expose a screened Interval within the tool, since the disposable tip remains in the ground after opening the screen to sample, individual borings must be advanced to collect each sample at various depths. Either procedure may then measure the depth to groundwater in the borehole to the :nearest one-one hundredth of one foot from surface grade, and also checked for the presence of separate phase product. The water entering the borehole was sampled using a clean disposable PVC/tube bailer, and carefully poured :into the appropriate laboratory prepared container with .minim-um cavitation. Each groundwater sample was labeled, logged onto a chain-of custody form, and placed in a chilled ice chest on crushed ice for transport to the laboratory_ Upon completion of drilling and collection of groundwater samples., the GeoProbe boreholes were backfilled with cement grout, placed from the bottom to top of the borehole per the permit requirements. All soil cuttings, decontamination and cement mixing water and consumable items used or generated in sampling were lefi in labeled 55-gallon closed top drums. The dru ns were left at the specified storage location at.Boyd Service Center. Page 3 of 1.4