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04 December 1995 AGE-NC Project No. 95-0183 Page 3 of 4 (PID: ThermoEnvironmental 580A, 10.0 eV, calibrated to isobutylene). Concurrently, the soil profile was described in accordance with Unified Soil Classification System(USCS). 4.0. FINDINGS 4.1. SOIL PROFILE The encountered soil profile was relatively uniform in between borings. The prevailing soil profile consisted of dark gray, fine sandy clay from surface grade to 10 feet bsg. This dark-colored interval appeared to be organic-rich. Light brown, fine-to medium-grained sand was encountered in the lower three feet of the soil profile. No organic vapors were detected in any of the soil samples using the PID. 4.2. LABORATORY RESULTS OF SOIL SAMPLES A total of six soil samples were submitted to MAI for analysis. Benzene was detected in samples B2- 10 and B44 at concentrations of 0.006 and 0.008 mg/kg (parts per million: ppm). No other petroleum hydrocarbons were detected in soil samples analyzed. Total lead was detected in all six samples at concentrations ranging from 3.0 to 9.7 ppm. Analytical results of the soil samples are summarized in Table 1. The laboratory report and chain-of-custody forms ar- included in Appendix A. _ 5.0. CONCLUSIONS Benzene was detected at concentrations slightly above the method reporting limits in two soil samples collected from the borings. Relative to the Total Threshold Limit Concentrations (TTLC) established the State of California, the concentrations of total lead detected in each sample should be considered "background" levels. Based upon the detection of benzene at trace concentrations, it appears that only residual hydrocarbons are present. Since the depth to ground water at the site is in excess of 70 feet bsg, the hydrocarbon residue should not pose a threat to ground water. 6.0. LIMITATIONS Our professional services were performed using that degree of care and skill ordinarily exercised by