ARCHIVED REPORTS_XR0009529 - Laserfiche WebLink

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• San Joaquin County EHD, who was present during most of the work. December 7, 1995 - Fourth quarter, 1995 monitoring, (seventh sampling, ) performed by Del-Tech Geotechnical Support Services . The hydraulic gradient was to the north at about . 008 ' /ft; the water table had dropped about 3 ' since the July sampling; it was measured at an average depth of 12 . 31 ' bgl . MW-2 still has the highest levels of BTEX & TPHg. MW-1 revealed minor amounts of toluene & xylene, most likely due to bailer blank contamination. Refer to that report for more complete details . RESULTS OF WORK PERFORMED ON JANUARY 4, 1996 - THREEE (3) ADDITIONAL SOIL/WATER PROBES : TEG mobilized a Strataprobe unit on site at 8-:00 AM, and decon- taminated equipment . Wm. J. Hunter, RG, from Wm. J. Hunter & Associates, (WJH) arrived at 8 :50 AM and discussed operations with TEG personel . The area where the soil/water probes were to be placed had previously been outlined and cleared by USA. The onsite lab was not used for this work; preserved soil & water samples were to be taken to FGL Environmental for analysis . The probe truck was mobilized on the site marked for D-1, (see PLATE III for its location. ) A clean split-spoon sample barrel was filled with metal tubes and attached to the stainless steel pipe. The tool was pushed and hammered to 12 ' bgl ; the sample chamber was opened, and the barrel driven to 1316" at 9 : 25 AM. The tools were retrieved and the sampler opened by the geologist . Contents consisted of 15" of tan, moist, silty clay. No odor was noted, and the bottom sleeve was promptly sealed with teflon tape & plastic end caps . The caps were thoroughly wrapped with duct tape, the tube labeled and placed on ice pending transport . Refer to PLATE Vi for a more complete description. A hydropunch tool was attached to the bottom of clean pipe, and the assembly was pushed and driven to 17 ' bgl . The tool was opened, and a clean stainless steel bailer was run inside the drill string. Water entry was good, and three (3) VOA' s were filled with muddy water. No odors were noted, and the water became clear after standing a few minutes . The bottom of the VOA' s contained very fine silty sand. The VOA' s were sealed, labeled, and placed on ice for preservation. Steve Sasson, RENS, from the San Joaquin County EHD arrived at this time and remained on site during the rest of the work. The hole was covered to prevent entry, and the probe truck • repositioned on location D-2 as shown on PLATE III . After decon- 7