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' 04 September 2001 <br /> AGE-NC Project No 97-0343 <br />' Page 3 of 4 <br />' water samples collected from monitoring wells MW 1,MW2 and MW3 at concentrations of 680 gg/l, <br /> 1,400 gg/1 and 110 gg/l, respectively <br />' BTEX compounds were detected In the groundwater samples collected from MW l,MW2 and MW3 <br /> at concentrations as high as 19 gg/l benzene, 1,400 gg/1 toluene, 360 gg/l ethylbenzene and <br /> 2,700 gg/1 total xylenes (MW2) Fuel oxygenated compounds were not detected at or above <br />' laboratory reporting limits in the ground water samples <br />' The analytical results of water samples collected in August 2001 are summarized on Table 2 The <br /> laboratory reports (MAI Lab I D No 74325-74331), QA/QC report and chain-of-custody form are <br /> included in Appendix B <br /> 4 0. SUMMARY AND CONCLUSIONS <br />' Based on the data collected from the site, AGE finds <br />' • Ground water flow at the site on 07 August 2001 was inferred to be generally toward the <br /> northwest at an average gradient of 0 005 feet/feet Ground water elevations at the site <br /> decreased an average of 4 36 feet since the second quarter 2001 monitoring event <br /> Ia Concentrations of dissolved TPH-g, TPH-d and BTEX compounds increased in samples <br /> from wells MWI, MW2 and MW3 compared to the previous monitoring event TPH-g, <br />' TPH-d, and BTEX compounds were not detected at or above laboratory reporting limits in <br /> ground water samples collected from MW4 through MW7 Fuel oxygenated compounds <br /> were not detected at or above laboratory reporting limits in the ground water samples The <br /> lateral extent of the fuel-impacted ground water appears to have been defined The current <br /> TPH-g,TPH-d and benzene isocontour maps are presented in Figures 4,5 and 6 The vertical <br /> extent of impacted ground water has not been defined <br /> I5.0. RECOMMENDATIONS <br /> Based on the findings of the environmental activities recounted in this report, AGE recommends <br /> continued quarterly monitoring of the ground water monitoring wells on-site The next monitoring <br /> event should be performed in November 2001 <br /> A work plan to define the vertical extent of impacted ground water has recently been submitted to <br /> San Joaquin County PHS-EHD AGE anticipates the work plan will be approved and work will be <br /> performed during the fourth quarter 2001 <br /> Advanced GeoEnvironmentai,Inc <br /> I <br />