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25 February 2004 <br /> AGE-NC Project No 95-0130 <br /> Page 4 of 7 <br /> 2 6 SURVEYING OF GROUND WATER MONITORING WELLS <br /> On 04 November 2003, a California state-licensed survey engineer from Mid Coast Engineers <br /> surveyed a reference point on the casing tops of wells EW-1, EW-2 and MW-8 to the nearest <br /> 0 01-foot relative to the City of Stockton Bench Mark Datum BM # 259 Measurements were <br /> obtained from conventional survey techniques in combination with global positioning system(GPS) <br />' techniques The surveying report (Mid Coast Engineers Job No 03222) is presented in Appendix <br /> B <br /> I3.0. FINDINGS <br />' Soil descriptions were utilized to construct geologic cross sections of the site, field data was utilized <br /> to select soil samples for laboratory analysis Petroleum hydrocarbon impact to saturated and <br /> unsaturated soil was assessed and quantified by laboratory analysis Laboratory analysis of ten soil <br /> samples detected TPH-g, BTEX, MTBE or 1,2-DCA compounds in five soil samples <br /> 31 STRATIGRAPHY <br /> Generally observed from EW-1, EW-2 and MW-8, a pale brown to dark brown,hard, fine sandy silt <br />' was encountered at depths between 5 feet bsg and 15 feet bsg, at 25 feet bsg and at 55 feet bsg A <br /> brown to gray-brown, dense, silty fine sand and fine sand was generally encountered at depths of 20 <br />' feet bsg and between 30 feet and 50 feet bsg <br /> Saturated soil was generally encountered at 45 feet bsg in bonngs EW-1, EW-2 and MW-8, ground <br />' water levels were measured at 43 feet bsg utilizing a Solinst water level meter Bonng logs are <br /> included in Appendix A General lithology beneath the site in cross-sectional view is depicted in <br /> Figures 3 and 4 <br /> 1 <br /> 3 2 FIELD EVIDENCE OF HYDROCARBON-IMPACTED SOIL AND GROUND WATER <br />' Faint to moderate hydrocarbon odor was noted in duplicate soil samples collected from soil boring <br /> EW-I at depths between 40 and 55 feet bsg and from EW-2 at depths between 30 and 55 feet bsg, <br />' hydrocarbon odor was not encountered in soil samples collected from MW-8 Petroleum <br /> hydrocarbon odors were noted on boring logs contained in Appendix A <br />' Utilizing a PID (Thermo Environmental 580B, 10 0 eV, calibrated to isobutylene) meter, organic <br /> vapor was observed in soil sample duplicates from EW-1 at depths between 35 and 55 feet bsg and <br />' Advanced GeoEnvironmental,Inc <br /> 1 <br />