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10 March 2000 AGE-NC Project No. 99-0628 Page 5 of 8 3.10. GROUNDWATER ELEVATION MEASUREMENT — On 08 March 2000, depth to ground water in each monitoring well was measured from the tops of the surveyed casings, utilizing a Solinst electronic water level meter. The data was acquired to determine the ground water flow direction and gradient. 4.0. FINDINGS Fuel-hydrocarbon impact to soil and ground water was assessed by laboratory analysis. The soil — profile was inferred from field descriptions. 4.1. STRATIGRAPHY Soil on the site consists primarily of sandy silt from 4 feet bsg to 59 feet bsg. Locally, silty sand, poorly sorted fine to medium sand, clayey silt and silty clay were encountered, but these soil types comprised a minor portion of the sampled soil column. The latter soil types appear to be relatively thin units that may have limited lateral continuity. Soil color ranged from light to dark brown and locally was gray. Saturated soil was encountered at depths of 54 and 59 feet bsg. Soil boring logs are in Appendix B. 4.2. RESULTS OF ANALYSIS OF SOIL SAMPLES Twelve soil samples were analyzed for TPH-g, TPH-d, and BTEX and MTBE in accordance with techniques prescribed by EPA Methods 8015 Modified and 8260 Modified. Seven of the same samples were analyzed for CAM 17 metals. The results of the laboratory analyses were as follows: • TPH-g, TPH-d, and BTEX compounds and MTBE were not detected in the soil samples analyzed. • Neither mercury nor silver were detected in the analyzed samples. • Possibly elevated concentrations of nickel and cadmium were detected; nickel concentrations in the 7 samples ranged from 139 mg/kg to 248 mg/kg; cadmium concentrations ranged from 139 mg/kg to 252 mg/kg. The nickel and cadmium concentrations were sub-equal in each sample analyzed. • Chromium concentrations ranged from 28 mg/kg to 60 mg/kg,which may reflect background concentrations; copper, lead, and zinc concentrations were low and very probably are at background concentrations based on results from other sites in the San Joaquin Basin. Advanced GeoEnvironmental,Inc.