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1 � • I Apnl 24, 19$9 File No 1705-2 III. SUMMARY OF CHEMICAL TEST RESULTS Table 1 presents a summary of the test results for the recent set of soil and water sam- ples obtained from the site The complete laboratory data package including QA/QC testing is contained in Appendix C These results combined with previous analyses indicate that soils in the upper 40+ feet in borings from the site are essentially free of fuel contamination IV. FINDINGS AND CONCLUSIONS From the data derived to date at the site, there are some significant findings and conclu- sions reached regarding the source and extent of the contamination on-site o Soils at the former main fuel tank area did not exhibit contamination by hydrocarbons to a depth of approximately 40 feet o It is unlikely that the main fuel tanks are responsible for the fuel contamina- tion in the groundwater since no indications of contaminants exist in the upper 40+ feet of soils (minor amount- 196 ppm of TPH - found in previous investiga- tions at 2 feet in TB-1) o Otherotential sources p of fuel and solvent contamination were identified in the site vicinity but were not fully investigated V RECOMMENDATIONS FOR ADDITIONAL INdESTIGATIONS/REMEDIATION The presence of the fuel constituents in groundwater is well above acceptable drinking water limits for benzene and possibly other organic compounds These conditions can be evaluated by drilling, sampling and monitoring additional monitoring wells over the long-term The currently defined groundwater contamination situation as well as information regarding the nearby production wells, and other hydrogeologic data may require some investigation,9 g based on the needs expressed by the San Joaquin County Health Dept. Additional wells in the site vicinity are expected to be needed if the extent _ of the fuel in groundwater is to be evaluated further 3