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_ INTERNATIONAL TECHNOLOGY CORPORATION Groundwater was encountered at approximately twenty-two feet below grade. Groundwater flows north-northeast with a gradient of 0.004 ft/ft (Figure 3). Elevation data is contained in Table 1. As such, MW-3 is located directly downgradient of the gasoline tank field and pump islands, while MW-1 and MW-4 are located side gradient and 14W-2 is located upgradient " the on-site petroleum hydrocarbon storage and transfer facilities, MW-4 is a,_J located adjacent to a waste oil and motor oil tank field. 4.2 ANALYTICAL 'ESULTS Laboratory results for soil and water samples are summarized in Table 2 and 3 respectively. Copies or the signed laboratory reports are included in Appendix D. No free product was observed in any of the monitoring wells. TPH as gasoline were reported only in water samples in wells MW-1 and MW-3, at concentrations of 0.140 ppm and 0.20 ppm respectively. Benzene concentrations in these two wells were 0.001 ppm and 0.033 ppm. Non-detectable levels of total petroleum hydrocarbons were reported in sails immediately above the water table in all boreholes. However, benzene and t ethyl benzene were detected in the twenty foot depth soil samples from MW-3 at s—` conc-ntrations of 0.82 ppm and 0.43 ppm respectively. ,r Fecal coliform was not detected in the groundwater s&,7,les in MW-1, MW-2, and MW-3. 5.0 CONCLUSIONS AND RECOMMENDATION The hydrogeology of the site consists mainly of clays with a thin four-foot " thick sand layer at approximately 24 feet below grade. The groundwater gradient is 0.004 ft/ft to the north-northeast. 5 Gasoline contaminants have been identified in the groundwater from wells MW-1 and MW-3. This could indicate a gasoline release in the area of the piping -------- -- --- -and/or the-three gasoliThe--point of the release may be identified during the removal of the tanks which is already in the planning process. 5 i:ENG:7024/072390