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03 October 2001 • AGE-NC Project No. 95-0 100 Page 5 of 6 3.2. GROUND WATER ELEVATION/FLOW DIRECTION AND GRADIENT ' The depths to ground water in wells MW-1 through MW-6 were measured between 47.75 and 56.59 feet below the tops of the well casings and the ground water elevations were calculated to be between 59.69 feet and 67.77 feet above mean sea level(msl)on 03 July 2001. Ground water elevation at the site decreased an average 0.39 feet between the May 2001 and the July 2001 ground water ' monitoring events. The ground water flow direction for the 03 July 2001 sampling event was inferred to be toward the 1 northwest at an average gradient of 0.003 feet/feet. Data from MW-4 was not used to determine ground water gradient. This well is screened at a deeper interval than the other wells. Figure 3 illustrates the contoured ground water elevations. 3.3. ANALYTICAL RESULTS OF SOIL SAMPLES A total of 9 soil samples were analyzed for TPH-g,BTEX and MTBE. No analytes were detected at or above laboratory reporting limits in the soil samples. ' Analytical results of soil samples are summarized on Table 2.The laboratory reports(MAI Lab I.D. No 69985 to 69993), quality assurance and quality control (QA/QC) report and chain-of-custody ' forms are included in Appendix E. ' 3.4. GROUND WATER ANALYTICAL RESULTS During the 03 July 2001 sampling event MTBE was detected in MW-1, MW-3, MW-4 and MW-6 ' by EPAmethod8020 at 150 micrograms per liter(µg/1),22 µg/l, 5.8 µg/1 and 7.8 µg/1,respectively. MTBE was confirmed in each sample by EPA method 8260 Modified at concentrations of 150 µg/1 17 µg/l, 3.1 µg/1 and 4.6 µg/l, respectively. No other fuel oxygenates were detected at or above rlaboratory reporting limits in the ground water samples.TPH-g and BTEX compounds were detected in the water sample collected from well MW-4 at concentrations of 93 µg/l TPH-g,6.0µg/1 benzene, ' 5.5 µg/1 toluene,2.2 µg11 ethylbenzene and 4.6 µg/1 total xylenes. A map depicting the approximate extent of dissolved MTBE is presented in Figure 4. _ During the 16_July 2001 sampling.event MTBE was detected in well MW-4 by EPA method 8260 at a'concentration of 1.4 µg/l. TPH-g, BTEX and other fuel oxygenated compounds were not detected at or above laboratory reporting limits in the ground water sample. Analytical results of ground water samples are summarized in Table 3. Copies of the laboratory ireports (McCampbell Analytical Laboratory ID 71866 to 71871 and 72638), quality assurance and ' quality control (QA/QC) data and chain-of-custody forms are in Appendix F. - Advanced GeoEnvironmental,Inc.