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I0,July 2002 i AGE-NC Project No. 95-0106 ' . Page 2 of 4 Temperature, pH and-conductivity were measured at 1-gallon intervals, as appropriate, using an Oakton water analyzer to monitor stabilization of these ground water parameters.Field data logs are included in Appendix B. Purged water was temporarily stored on-site in 55-gallon.DOT-approved IH-17 storage drums pending proper disposal. 2.3. COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES Water samples were collected from monitoring wells MW-1.through MW-7 using new disposable bailers. The samples were transferred into 40-m1 EPA-approved vials containing 0.5 ml 18% hydrochloric acid as a preservative. The sample vials were then labeled with the monitoring well designation, date;time of sampling and the sampler's initials. The samples were transported in a chilled container under chain of custody to McCampbell Analytical, Inc: (MAI), a California Department of Health Services-certified analytical laboiratory for analysis. The samples were analyzed for: • win accordance with petroleum hydrocarbons quantified as gasoline (TPH-g) EPA Method 8015 Modified, and , IBenzene, toluene, ethylbenzene, and total xylenes (BTEX) and methyl tertiary butyl ether (MTBE) in accordance with EPA Method 8021. 3.0. FINDINGS Ground water.elevation and flow direction were inferred from field data; hydrocarbon-impact to ' ground water was was quantified by laboratory analysis,of the ground water samples. ' 3.1. GROUND WATER ELEVATION,AND,FLOW DIRECTION ; The relative ground water elevation ranged,from 32.76 feet (MW-6 upper and MW-6 lower) to ' 33.59 feet:(MW-2), decreasing an average,of 0.30 feet since the February 2002 monitoring event.' The water table appears as a north plunging ridge which transitions eastwards to a north-plunging trough..The east limb of the ridge flows toward the northeast at a gradient,of approximately 0.005., ft/ft, and the west limb flows toward the north-northwest at agradient of approximately 0.006 ft/ft. ' water Ground water elevation data Is presented,to Table 1; the contouredground elevation data is, shown on Figure.3. 1 Advanced GeoEnviron mental,Inc.