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municipal water supplier), and the Port In addition, a physical search of the area was conducted to visually identify supply wells in the area Locations of all wells identified within the 2,000-foot radius are depicted on Figure 4 Construction details of wells located are provided in Appendix C 4.0 INVESTIGATION FINDINGS 4.1 GROUNDWATER GRADIENT ' Water levels measured in monitoring wells at the site on July 9, 1999 ranged from 10 39 to 11 10 feet below top ofeasing(Table 1) The potentiometrnc surface interpreted from these measurements is shown on Figure 3 The water-level measurements indicate that the apparent lateral hydraulic ' gradient of the water table is to the northeast at a gradient of about 0 004 feet per foot or 21 feet per mile ' 4.2 SOIL AND GROUNDWATER ANALYTICAL RESULTS Analytical results for soil and groundwater samples collected during this investigation are presented on Table 2 and Figure 5, along with the analytical results from the initial groundwater investigation for comparison The soil sample results for MW3-2 and MW3-3 confirm the results of the initial ' investigation, with the PHC concentrations in both borings attenuating with depth (Table 2 and Figure 5) In MW3-1, the PHC concentrations are higher in the 30-foot soil sample than in the 25- foot sample, although not as high as in the 20-foot sample results from the initial investigation The highest concentrations are still in the 15- to 20-foot samples in all three boring locations ' The highest concentrations of PHCs in groundwater samples collected from the monitoring wells occurred in MW3-3, which had TPHg of 8 42 mg/l, toluene of 2 5 mg/l, and a benzene of 0 113 mg/1 Concentrations of PHCs at MM3-l and NM-2 were significantly lower with TPHg of about ' 0 6 mg/l,toluene of 0 3 mg/l, and benzene of 0 02 and 0 12 mg/l, respectively All of these values were substantially lower than the maximum PHC concentrations in groundwater observed during ' the initial investigation, which showed 1,600 mg/l TPHg, 19 mg/l toluene, and 2 1 mg/1 benzene 4.3 SUPPLY WELL SURVEY ' California Well Service (CWS), the purveyor of municipal water in the vicinity of the Port, was ( ) P Y P contacted on June 1, 1999 to determine whether they had any wells near the site CWS reported ' s3addumpLvipa 7 PHILIP P. Ross, R.G.