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Soil samples will be collected for laboratory analysis at 30-foot intervals along the perimeter of <br /> the excavation at a depth approximately 12 feet below the existing ground surface. The 12-foot depth <br /> correlates with the historical capillary fringe zone. Soil samples will also be collected at a depth of 7 <br /> feet along the perimeter south of hydraulic sump #1 where the subsurface investigation data indicates <br /> that the shallow impacted soils (9.5 foot depth, Figure 3) extend outside the area of the deeper <br /> impacted soils (13 foot depth, Figure 4). <br /> Soil samples will be collected by driving clean brass liners into the exposed side-wall of the <br /> excavation, or from the excavator bucket if sampling directly from the side-wall is not possible. The <br /> liners will be sealed at the ends with Teflon tape, capped, wrapped with duct tape, and labeled. All <br /> samples will be stored in a cooler chilled with Blue Ice and delivered immediately under chain-of- <br /> custody procedures to a California certified laboratory for immediate analysis. <br /> All reasonable and practicable effort will be made to excavate the contaminated soil in the <br /> historical capillary fringe zone to below detectable levels of hydraulic oil (50 mg/kg) given structural <br /> limitations. As mentioned above, certain structural components will necessarily be required to be <br /> supported to facilitate removal of contaminated soils. However, in some cases low levels of <br /> contaminated soil may be required to be left in place along the shallow perimeter zone (i.e. above the <br /> historical capillary fringe) based upon professional judgement of factors such as structural and <br /> engineering components, low potential to impact groundwater, structural constraints, and <br /> contamination concentration levels. LOF will make practicable efforts to characterize any <br /> contaminated soil left in-place. <br /> 5.0 LABORATORY ANALYSIS <br /> All soil samples will be submitted to GeoAnalytical Laboratories in Modesto, California, for <br /> immediate analysis of total extractable petroleum hydrocarbons (TEPH) quantified as hydraulic oil, <br /> 3 <br /> C 1 CONDOR <br />