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' r 05 October 1999 <br /> AGE-NC Project No 95-0143 <br /> 1 Page 3 of 4 <br />' leaks were determined to be in the previously existing line The leak is suspected in the underground <br /> portion of the line, but the location has not been confirmed Upon repair of the gas line, operation <br /> of the SVE and IAS units will be initiated <br />' 3 0. FINDINGS <br /> Ground water elevation and flow direction were calculated from field data, hydrocarbon-impact to <br />' soil and ground water was inferred from laboratory analysis and field observations <br />' 3 1 GROUND WATER ELEVATION AND GRADIENT <br /> The elevation of ground water in each well was calculated by subtracting the depth to water from <br />' the surveyed casing elevation (Table 1) Between May and August 1999, ground water elevations <br /> decreased an average of 0 52 feet During the August 1999 monitoring event, ground water was from <br /> 0 2 feet to 7 8 feet above the screened interval in each monitoring well Ground water was within <br />'•' the screened intervals of each vapor well for free product determination The approximate hydraulic <br /> gradient was calculated to be 0 0012 ft/ft with a northeasterly flow direction on the subject property <br />' Ground water elevation contours for the August 1999 monitoring event are illustrated in Figure 4 <br /> I32 ANALYTICAL RESULTS OF WATER SAMPLES <br /> During the August 1999 monitoring event, TPH-g was detected in samples collected from MW3, <br />' MW-7, MW-9 and MW-10 at concentrations of 200,000 parts per billion (ppb, reported as <br /> micrograms per liter), 2,500 ppb, 19,000 ppb and 280 ppb, respectively BTEX compounds were <br /> detected in each well, except MW-14, at concentrations as high as 50,000 ppb (toluene in the sample <br />' from MW-3) Benzene concentrations ranged from below detection limits to 14,000 ppb Oxygenates <br /> were not detected at the site during the August 1999 sampling event <br /> Measurable free product was not encountered in any of the wells on the site Analytical results of <br /> ground water samples for August 1999 are summarized on Table 2 Analytical results of historical <br />' ground water samples are summarized on Table 3 The laboratory report(MAI Laboratory I D Nos <br /> 17071-17079) and chain-of-custody forms are included in Appendix B <br /> I4 0. SUMMARYICONCLUSIONS <br /> i <br /> Based upon data collected from the site, AGE concludes <br /> Advanced GeoEnrironmental,Inc <br />