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i 26 June 2002 • AGE-NC Project No 95-0144 ' Page 3 of 5 ' 3.0 FINDINGS Ground water elevation and flow direction were Inferred from field data, hydrocarbon-impact to ground water was quantified from laboratory analysis of the ground water samples ' 3 1 GROUND WATER ELEVATION AND GRADIENT The elevation of ground water in each well was calculated by subtracting the depth to water from the ' surveyed casing elevation (Table 1) During the May 2002 monitoring event the average ground water elevation at the site was 6 91 feet below mean seal level (MSL), a decrease of 0 04 feet since the February 2002 monitoring event The average depth to water at the site was approximately 16 55 ' feet bsg The approximate hydraulic gradient for the May 2002 monitoring event was inferred to be 0 002 ft/ft with a flow direction toward the north-northeast(Figure 3) ' Ground water was within the screened intervals of the shallow-screened wells MW-13, MW-19A, MW-20A and MW-2 I A,but was between approximately 0 14 feet and 5 19 feet above the screened ' • Interval in the shallow-screened wells MW-1,MW-2,MW-4,MW-5,MW-8,MW-11 and MW-12 Ground water elevations in the deep-screened nested wells MW-19, MW-20 and MW-21 were ' between 15 9 feet and 184 feet lower in deeper screened intervals beneath a 5-to 10-foot clay layer identified at 37 to 50 feet bsg than in the wells screened above the clay layer The approximate hydraulic gradient in the deeper screened ground water monitoring wells for the May 2002 ' monitoring event was inferred to be 0 006 ft/ft with a flow direction toward the east-southeast (Figure 4) 3 2 ANALYTICAL RESULTS OF WATER SAMPLES ' During the May 2002 monitoring event, TPH-g was detected in samples from monitoring; wells MW-21A and MW-21B at concentrations of 7,300 micrograms per liter (µg11) and 750 µg/1, respectively TPH-d was detected in samples collected from MW-20A, MW-21A and MW-21B at ' concentrations of 110 µg/l, 8,100 µg/1 and 260 µg/1, respectively TPH-mo was not detected at or above laboratory reporting limits in any of the ground water samples collecte during the May 2002 monitoring event The extent of hypdrocarbon-impacted ground water is illustrated in Figure 4 ' Various BTEX compounds were detected in samples from wells MW-21A and MW-21B at concentrations as high as 130 µg/l benzene, 17 µg/1 toluene, 160 µg/1 ethylbenzene and 3 8 µg11 xylenes, in sample MW-21A Advanced GeoEnvironmental,Inc