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W lie 20 December 2001 ' AGE-NC Project No 95-0144 Page 5 of 7 ' events Pumping and disposal was completed by American Valley Waste Oil, Inc of Delhi, California The purge water was disposed at Seaport Environmental located in Redwood City, California A copy of the waste disposal manifest is included in Appendix C 1 , ' 4.0. 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 4 1 RELATIVE 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) Between August 2001 and November 2001, ground water elevation decreased between 0 93 feet and 1 20 feet m the monitored wells The approximate hydraulic gradient for the November 2001 monitoring event was inferred to be 0 002 ft/ft with a flow ' direction toward the north-northeast Ground water elevation contours derived from data collected on 16 August 2001 are depicted in Figure 3 Ground water was between approximately 1 39 feet and 4 44 feet above the screened interval in monitoring wells MW-1, MW-2, MW-4,MW-5 and MW-8 ' Ground water was within the screened intervals of MW-11, MW-12, MW-13, MW-19A, MW-20A and MW-21 A ' Ground water elevations in nested wells MW-19, MW-20 and MW-21 were between 1 58 feet and 1 86 feet lower in deeper screened intervals beneath a clay layer than in the shallower screened intervals Data from wells with the upper screened intervals, established in first-encountered ground ' water, was utilized for gradient determination ' 4 2 ANALYTICAL RESULTS OF WATER SAMPLES ' During the November 2001 monitoring event,TPH-g was detected in samples from monitoring wells MW-21A and MW-21B at concentrations of 3,000 micrograms per liter (µ.g/1) and 860 µg/l, respectively Various BTEX compounds were detected in samples from wells MW-21A and ' MW-21B at concentrations as high as 230 µg/l (ethylbenzene, MW-21A) TPH-d was detected in samples collected from MW-19A, MW-20A, MW-21A and MW-21B at concentrations of 52 µg/1, 100 µg/1, 6,900 µg/1 and 420 µg/l, respectively TPH-mo was detected in monitoring well sample ' MW-21A at a concentration of 840 µg/1 The extent of hypdrocarbon-impacted ground water is illustrated in Figure 4 Advanced GeoEnviropmental,Inc