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i <br /> i02 December 2002 <br /> AGE-NC Project No 98-0433 <br /> Page 3 of 4 <br />' Ground water flow direction and gradient were calculated from the September 2002 gauging data <br /> Ground water flow was inferred to be toward the east with a gradient of 0 004 ft/ft (Figure 3) <br /> 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> TPH-g was detected in the ground water samples collected from MW-1,MW-2,MW-6,MW-7 and <br /> MW-8 at concentrations ranging from 120 micrograms per liter (µg/1) (MW-7) to 420,000 µg/1 <br /> (MW-6) TPH-d was detected in the ground water samples collected from MW-2 and MW-6 at <br /> concentrations of 81 µg/1 and 9,400 µg11, respectively V/ <br /> One or more BTEX compound were detected in samples MW-1, MW-6 and MW-7, the maximum <br /> I concentrations were 10 µg/1 benzene (MW-1), 3 4 µg/1 toluene (MW-7), 3 3 µg/l ethylbenzene <br /> (MW-6) and 22 µg/1 xylenes (MW-6) ✓ <br /> MTBE was detected by EPA method 8260 in samples MW-1, MW-2 and MW-8 at concentrations <br /> of 2,400 µg/1, 5 0 µg/1 and 44 µg/l, respectively TAME and TBA were detected in sample MW-1 <br /> at 57µg/1 and 270 µg/l, respectively <br /> lie <br /> Target analytes. were not detected at or above laboratory reporting limits in the water sample <br /> g Yt rY p g <br /> collected from the domestic well (DW-1) on-site I--,' <br /> Analytical results from ground water samples are summarized in Table 2 The laboratory report <br /> (CalTech ID 0209-130-1 to 9),quality assurance and quality control(QA/QC)and chain--of-custody <br /> are included in Appendix B The distribution of dissolved hydrocarbons is depicted in Figure 4 <br /> I4.0 SUMMARY AND CONCLUSIONS <br /> Based upon the data collected during the September 2002 monitoring event, AGE concludes <br /> • Ground water at the site was encountered at approximately 2170 to 23 68 feet below the <br /> casing tops The prevailing ground water flow direction was generally toward the east at a <br /> gradient of 0 004 ft/ft <br /> • The highest concentration of TPH-g was in the area of monitoring wells MW y kl eft� <br />' cen and well MW-6 No -- V /,-a.1 a-o 1 D 3 <br /> • In general, TPH-g concentrations in ground water increased slightly in the samples from <br />' wells MW-1, 1`4'4--2, MW-7and M -8 (Figure 4) and increased drastically in the sample.5 <br /> AP cn� <br /> collected from well MW- e une 2002 sampling event TPH-g in sample MW-6 is <br /> • the highest recorded in the three years of sampling - <br />' Advanced GeoEnvironmental,Inc <br />