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• 23 July 2001 AGE-NC Project No 95-0143 Page 3 of 4 ' 3 1 GROUND WATER ELEVATION AND GRADIENT The elevation of ground water In the twelve wells was calculated by subtracting the depth to water ' from the surveyed casing elevation (Table 1) Ground water elevations decreased in the monitored wells an average 0 10 feet between the February 2001 and May 2001 monitoring events Ground ' water was within the screened intervals of MW-17, MW-22, MW-23 and MW-24 and inferred to be within the screened interval of each vapor well Ground water ranged from 0 57 feet to 7 51 feet above the screened interval in the other eight monitoring wells The approximate flow direction was ' toward the northeast with a gradient of 0 001 feet/feet at the subject property Groundwater elevation contours for the May 2001 monitoring event are illustrated m Figure 3 3 2 ANALYTICAL RESULTS OF WATER SAMPLES ' During the May 2001 monitoring event, TPH-g was detected in samples collected from monitoring wells MW-3, MW-6, MW-7, MW-9, MW 10 and MW-22 at concentrations ranging from 390 µg/1 (MW-6)to 160,000 µg/l(MW-3) BTEX compounds were detected inwells MW-3, MW-6,MW-7, ' . MW-9, MW-10 and MW-22 at concentrations as high as 34,000 µg/l toluene (MW-3) MTBE was not detected in samples collected from the site during the May 2001 sampling event TBA was detected in the sample collected from MW-24 at a concentration of 100 gg/1 Figure 4 illustrates the ' approximate extent of TPH-g and benzene contarrunation in ground water Measurable free product wasnot encountered in any of the wells on the site Analytical results of ground water samples collected during the May 2001 monitoring event are summarized on Table 2 Analytical results of historical ground water samples are summarized on Table 3 The laboratory report (MAI Laboratory IDs 68089 through 68100) and chain-of-custody forms are included in ' Appendix C ' 4.0. SUMMARY/CONCLUSIONS Based upon data collected from the site, AGE concludes Ground water elevation increased approximately 0 10 feet between February 2001 and May 2001 Ground water elevation was within the screened interval of MW-17, MW-22, MW-23, MW-24 and the five vapor extraction wells, but above the screened interval of the other eight monitoring wells The exposed portion of the screened interval in the five vapor ' extraction wells was within a silty layer and just above a sandy layer The inferred ground water flow direction renins variably toward the north to northeast at the site Advanced GeoEnvirunmental,Inc