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F� <br /> Site Characterization Report: 7500 West Eleventh Street. Tracy, C4. Page 11 <br /> dispensed by the laboratory. The sample jars and vials were then tightly closed, labeled <br /> for identification, entered into chain-of-custody control and packed in an electric cooler <br /> on chemical ice for transport, within 10 hours, to Sequoia's laboratory in Walnut Creek, <br /> California. <br /> 1; At the laboratory, the samples of groundwater recovered from the push-probe holes were <br /> analyzed for the same suite of analytes as applied in the case of the soil samples and <br /> which is defined in the table in Section 3.4.1. <br /> The laboratory was requested to analyze the six groundwater samples recovered from <br /> push-probe borings PP-1 through PP-6, which had been recovered in the early stages of <br /> the drilling program, on a 24-hr expedited schedule so that the results could be available <br /> in the field to assist in the selection of subsurface exploration locations drilled later in the <br /> program. <br /> � I <br /> The results of the analyses of soil and groundwater samples recovered from the push- <br /> probe borings are tabulated in Tables I and 2, respectively. (Note: analyses for TPHg and <br /> E' BTEX compounds were not performed on the samples recovered from depths of 8 ft. and <br /> 11 ft. from PP-1 because insufficient soil was retained in the split-spoon liners for these <br /> - ; analyses to be made, in addition to the analyses that were performed for TPHd.) <br /> Copies of the certificates of analysis issued by the laboratory, together with their <br /> associated chain of custody documentation are compiled in Appendix B. <br /> 3.4.3 Selection of Locations for Push-probe Borings <br /> Based on the information obtained when underground tanks were removed from the site, <br /> a plume of hydrocarbons was suspected to emanate from the area where the fueling <br /> station's pump islands had been located, although the presence of other plumes due to <br /> leakage at other locations such as the former underground storage tank pits could not, at <br /> that stage, be eliminated. This called for push-probe borings to be located within a <br /> t f reasonable. distance beyond the anticipated plume limits where soil and groundwater <br /> would be free of petroleum hydrocarbons. In addition,push-probe borings were needed to <br /> investigate the maximum depth to which the soil near the source of the leakage had been <br /> E affected by fuel hydrocarbons. <br /> The first push-probe boring drilled (PP-1) was located to the southwest of the area <br /> formerly occupied by the fueling station's pump islands to investigate whether its <br /> location was beyond the southern limit of a plume of hydrocarbons that was assumed to <br /> have originated in that area. <br /> PP-2, PP-3 and PP-4 were drilled to investigate the lateral extent of the anticipated plume <br /> along a line extending from east to west at the West Eleventh Street frontage of the <br /> subject property. <br /> sic <br /> � I <br />