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i I28 November 2005 AGE-NC Project No 00-0696 IPage 4 of 5 • One well was located at 13999 West Highway 12, and • One well was located approximately 100 feet south of Highway 12,approximately 0 45 miles east of the Little Potato Slough Bridge On 05 October 2005, an AGE representative performed a reconnaissance of visually observable potential sensitive receptors located within a 2,000-foot radius of the site During the reconnaissance, one domestic well was located on the eastern end of the Termmous Market site No other visible potential receptors were noted during the reconnaissance Copies of the well drillers' reports for wells located within a 2,000-foot radius of the site are included in Appendix D A summary of the water wells located from the review of the well drillers' reports, as well as all visually observed wells located during the reconnaissance, is included in Table 3 Locations of the wells are depicted on Figure 4 4.0. SUMMARY AND CONCLUSIONS Based on the data collected from the site, AGE concludes • On 23 August 2005, ground water elevation at the site ranged from 17 45 feet to 17 68 feet below MSL, and averaged approximately 17 57 feet below MSL, indicating an increase in ground water elevation of approximately 0 16 feet since the last monitoring event in May 2005 • Ground water at the site was inferred to be flowing in a north-northeast plunging trough under hydraulic gradients of approximately 0 007 ft/ft or less • TPH-g was detected in the ground water samples collected from wells MW-2 and MW-3 at concentrations of 100 pg/l and 1,600 µg/l,respectively BTEX compounds were detected in the ground water samples collected from wells MW-2 and MW-3 at the following maximum concentrations in well MW-3 50 µg/l benzene, 50 µg/l toluene, 39 µg/1 ethylbenzene, and 74 µg/1 total xylenes MTBE was detected in samples MW-2 and MW-4 at concentrations Iof 85 µg/1 and 14 µg/1, respectively • The concentrations of MTBE and benzene in wells MW-2 and MW-3 exceed the DHS's Maximum Contaminant Levels (MCLs) of 13 µg/1 and 1 µg/1 for drinking water • The lateral extent of petroleum hydrocarbon contamination is defined to the west by monitoring well MW-1 • In August 2005, an AGE representative reviewed well drillers' reports from the California • Department of Water Resources-Central District for water wells located in the surrounding Advanced GeoRnvironmental,Inc