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t... .i 26 February 2007 AGE-NC Project No. 97-0327 Page 3 of 4 3.2. ANALYTICAL RESULTS OF MONITORING WELL WATER SAMPLES ` A total of four ground water samples were submitted to CalTech Environmental Laboratories (CTEL), a DHS-certified laboratory, for analysis. TPH-g was detected in the sample from MW-3, at a concentration of 200 µg/l. BTEX constituents were detected in the sample from MW-3 at concentrations of 4.1 µg/1 ethylbenzene and 26.2 µg/1 xylene. Fuel additive 1,2-DCA was detected in the sample from MW-4 at a concentration of 51 µg/l. No other analytes were detected at or above laboratory reporting limits in any ground water samples collected. i Analytical results of the ground water samples are summarized in Table 3. The laboratory reports (CTEL reference No. CT214-0609030) and chain-of-custody forms are presented in Appendix B. Documents confirming the upload of laboratory electronic deliverable format(EDF)files and depth to water measurements to Geotracker are included in Appendix C. 3.3. ANALYTICAL RESULTS OF DOMESTIC WATER WELL SAMPLES Grab water samples were not collected from off-site domestic water wells located at 451 and 452 North Lillian Avenue during this quarterly monitoring event. 4.0. SUMMARY AND CONCLUSIONS The implications from the September 2006 ground water monitoring event are as follows: • Ground water flow direction at the site was inferred to be toward the southwest at a gradient of 0.006 ft/ft or less; previous ground water monitoring events at the site have determined the prevalent ground water flow direction to be towards the south. • Due to the low gradient at the site, slight variations in ground water measurements or changes of recharge/discharge of the local ground water could have modified ground water flow direction. r • The ground water elevation at the site was not within the screened intervals of wells MW-1, MW-2, MW-3 or MW-4;the wells were "flooded" by an average of 4.23 feet and may not be representative of first ground water conditions. • Average depth to ground water decreased by approximately 2.32 feet since the last quarterly monitoring event in June 2006; this decrease in the ground water table may have caused additional desorption of soil contaminants in the capillary zone,resulting in the detection of `„ Advanced GeoEnvironmentai,Inc.