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' GEOMATWIX <br /> California, a California state-certified analytical laboratory Chain-of-custody records are <br /> ' included in Appendix B <br /> Purge water was temporarily stored on site in sealed container pending off-site disposal <br /> ' 3.2 ANALYTICAL METHODS <br /> ' Zymax analyzed groundwater samples for TPHg (C4 to C32 carbon range) and TPHd (C8 to Coo <br /> carbon range) using EPA Method 8015 Modified <br /> ' 4.0 FINDINGS <br /> The findings from the February and March 2005 sampling events are presented in this section <br /> ' Water-level elevations are presented in Section 4 1, and the analytical results of the <br /> groundwater samples are presented in Section 4 2 <br /> ' 4.1 WATER LEVELS AND PRODUCT THICKNESS MEASUREMENTS <br /> ' Historical water level elevations are presented in Table 1 Depth to groundwater on <br /> February 25, 2005 ranged between 4 95 feet and 10 10 feet below the top of the well casings <br /> with groundwater elevations ranging between 0 15 feet above and -1 87 feet below mean sea <br /> ' level (msl) (Table 1) A water-level elevation map, presented on Figure 3, indicates a <br /> horizontal hydraulic gradient to the south with a magnitude of 0 011 feet per foot Historical <br /> ' measurements have indicated a south and southwest flow direction <br /> No free product or sheen was observed in the monitonng wells No product was present in the <br /> ' "petro trap" installed in monitoring well MW-2 A sheen was observed in MW-2 on <br /> January 24, 2005 during an inspection of the "petro trap" installed in MW-2 <br /> ' 4.2 GROUNDWATER ANALYTICAL RESULTS <br /> ' The analytical results for groundwater samples collected from the project wells (MW-1 through <br /> MW-7) are summanzed in Table 2 and presented on Figure 4 For comparison purposes, <br /> ' Table 4 also includes RWQCB WQOs <br /> The results of the analyses on groundwater samples collected dunng the February and March <br /> ' 2005 event indicated that no analytes were detected above laboratory reporting limits for <br /> samples from upgradlent well MW-1 or from downgradient wells MW-5 and MW-6, which is <br /> ' consistent with historical results TPHd was detected in samples collected from monitonng <br /> wells MW-2, MW-3, and MW-4, which is consistent with historical results However, low <br /> concentrations of TPHd were detected in the sample from deeper zone well MW-7 (110 µg/1), <br /> ' 1 0mDc_Safe19000s19963 00111 st qtr 200512 T.ttilzt doc 4 <br />