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• 10 August 2004 AGE-NC Project No 96-0232 Page 8of10 - 3 5 ANALYTICAL RESULTS OF WELL DEVELOPMENT WATER SAMPLES A total of two mointonng well development samples collected from MW-19A and MW-19B were .submitted to Cal Tech Environmental Laboratories,- a DHS-certified laboratory for analysis of - - ---F- petroleum hydrocarbons TPH-g,TPH-d and TPH-mo were not detected from laboratory analysis of well development water samples BTEX constituents were not detected from laboratory analysis of well development water samples MTBE was detected in the water samples collected from MW-I9A and MW-19B at concentrations of 5,300 µg/1 and 58 lig/l, respectively No other fuel components were detected above the laboratory reporting limits Analytical results of the ground water samples are summarized in Table 6 The laboratory reports (McCampbell Analytical, Inc work order 0405340) and chain-of-custody forms are presented in Appendix E i 4 0. SUMMARY AND CONCLUSIONS Previous soil characteristics data obtained by CPT investigation and soil bormg/monitonng well observations enabled AGE to define five informal hydrogeologic flow units (Final Remediation Plan, dated 31 August 2000) in the area of the Flag City Chevron site The informal hydrogeologic flow units were defined as First Zone(10-35 feet bsg),Second Zone(40-60 feet bsg),Rocky's Upper - Zone (65-75 feet bsg), Secondary Aquifer Zone (85-105 feet bsg), and Primary Aquifer Zone (130-150 feet bsg) The findings of the soil sample investigation results are as follows Generally, less permeable, fine sandy silts and clayey silts were encountered at depths between 5 and 10 feet bsg and between 25 and 35 feet bsg, more permeable, silty fine sands and fine to medium sands were encountered at depths between 10 and 25 feet bsg (First Zone) and between 35 and 50 feet bsg (Second Zone) Geologic cross section E-E' depicts the informal hydrogeologic units beneath the site (Figure 3) TPH-d was detected in the 30-foot soil sample collected from boring P-41 (near well MW-8) at a concentration of 1 7 mg/kg MTBE was detected in soil from bonngs P-40A (30 feet and 45 feet), P-41 (30 feet), P-43 (30 feet)and MW-19(18 feet and 30 feet) at concentrations as high as 0 39 mg/kg(P43-30) Advanced GeoEnvironmental,Inc