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As shown in the table, TPH-G was detected in only two soil samples, one from SBI and the other from SB2 The concentration detected in SBI at 50 feet below ground surface (bgs) was very low The 20 feet bgs sample from SB2 was analyzed a second time because the surrogate recovery from the initial analyses was high due to background matrix interference from high concentrations of TPH compounds, however, the second analysis was one day out of hold The initial result, 6,000 mg/Kg, is most likely biased high, based on the surrogate recovery, however the second result, 210 mg/Kg is not reliable because the holding time was exceeded It can be concluded that the 20 feet sample from SB2 contained elevated concentrations of TPH-G BTEX compounds were only detected in the upper two soil samples from SB2 at low concentrations TPH-G and BTEX were not detected in either groundwater samples collected from soil borings SB3 or SB4 4.0 SUMMARY OF GROUNDWATER FLOW DIRECTION RESEARCH WESTON reviewed project files at the EHD and other available groundwater maps to evaluate the groundwater flow direction in the site vicinity The Spring 1992 and 1993 "Lines of Equal Elevation of Water in Wells" maps compiled by the San Joaquin County Flood Control and Water Conservation District indicated regional groundwater flow in the site vicinity is to the south or south-southeast Groundwater flow at the Guild Winery on Winemaster Way (located approximately 0 75 mile northeast of the site) between 1985 and 1990 was generally to the south or southwest This small variation from the regional gradient is reasonable due to the presence of industrial waste ponds located to the north and northwest of the winery The groundwater flow direction at the Roberts Oil Company located east of the site vaned from east to south-southwest between 1988 and 1990. In 1988, the apparent gradient was to the southwest, however three of the four wells were located near a northeast-southwest line, which most likely would skew the apparent groundwater flow direction During this period, the groundwater direction at the site was to the northeast, however, the fish ponds on site most likely directly influenced the local gradient Based on available information it is likely that at present, groundwater flow at the site is to the I south or southeast Water elevation data from the two existing site wells cannot be used to indicate a gradient because there are only two data points However, groundwater elevations measured in these wells suggest that groundwater flow could be to the east or southeast. 5.0 CONCLUSIONS AND RECOMMENDATIONS As shown on Table 1, the 20 feet bgs sample from soil boring SB2 contained an elevated concentration of TPH-G and low concentrations of BTEX compounds Only a very low concentration of TPH-G was detected in the 50 feet bgs sample from soil boring SBI TPH-G and BTEX were not detected in the hydropunch groundwater samples I5MxRPTs\s1CMVCn1 WP 6 0829194