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r P <br /> Y <br /> Y <br />' 06 May 1997 , <br /> S AGE-NC Project No 95-0111, <br /> Page 2 of 4 <br /> 3.0: FINDINGS <br /> 3 1 GROUND WATER FLOW DIRECTION AND GRADIENT <br />' The relative elevation of ground water in each well was calculated by subtracting the ground water' <br /> depth from the surveyed casing elevation The depths to ground water and relative ground water <br /> elevations are tabulated in Table 1 - Relative Ground Water Elevations All wells were surveyed <br /> relative to casing of monitoring well MW-1, which had been assigned an arbitiary casing elevation <br /> of 20 feet <br /> The depth to ground water ranged from 9 75 feet in MW-1 to 6 52 feet in MW-4 The relative ground <br /> water elevation at the site ranged from 9 33 feet in MW-6 to 10 81 feet in MW-3 The relative <br /> ground water elevation decreased an average of 0 07 feet at the site between December 1996 and, <br /> March 1997 <br /> Ground water flow direction at the site was toward the north-northeast Ground water gradient at the <br /> south end of the site was approximately 0 0055 ft/ft The gradient steepens towards the north end of <br /> the site was approximately 0 0066 ft/ft Ground water elevation isocontours are depicted in Figure <br /> 3 -Relative Ground Water Elevation <br /> 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> TPH-g was detected in samples collected from monitoring wells MW-1, MW-4 and MW-5 at <br /> concentrations of 190, 190 and 170 k4l (micrograms per liter or parts per billion ppb),respectively <br /> TPH-d was detected in samples from wells MW-4 and MW-5 at concentrations of 13,000 ppb and , <br /> 10,000 ppb, respectively Laboratory notations for samples collected from wells MW-4 indicated <br /> the presence of an immiscible sheen <br />' Benzene was detected in samples collected from wells MW-1 and MW-4 at concentrations as high <br /> as 73 ppb, ethyl benzene, toluene and xylenes were detected in samples from-MW-1, MW-2 and <br /> MW-5 at concentrations as high as 3 5 ppb <br /> MTBE was detected - - <br /> by EPA method 8020/602 m samples collected from wells MW 1, MW 4 and <br /> MW-5 at concentrations of 100, 37 and 33 ppb, respectively <br /> Analytical results of ground water samples are summarized in Table 2-.4nalytical-Results of Ground <br /> I Water Samples The laboratory report(MAI Laboratory Nos 74778 to 74783), QA/QC Report and <br /> chain-of-custody are included in Appendix B <br /> v , <br /> r <br /> r <br />