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' 24 August 2001 AGE-NC Project No 95-0141 ' Page 2 of 4 ' 2 2 GROUND WATER SAMPLE COLLECTION A water sample was collected from each well using a new, clean, disposable plastic bailer ' Immediately upon retrieval,the samples were transferred into three 40-m1 EPA-approved VOA vials containing 0 5 ml 18% hydrochloric acid as a sample preservative The samples were logged on a chain-of-custody form, stored in a chilled container and transported under chain-of-custody to ' McCampbell Analytical Inc (MAI), a California Department of Health Services (DHS)-certified laboratory The ground water samples were analyzed for ' & Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Method 8015 Modified, ' 0 Volatile aromatic hydrocarbons - benzene, toluene, ethylbenzene and total xylenes (BTEX) in accordance with EPA Method 8020, and ' 9 Oxygenated compounds - di-isopropyl ether (DIPS), ethyl tertiary-butyl ether (ETBE), methyl tertiary-butyl ether (MTBE), tertiary-amyl methyl ether (TAME), tertiary butanol (TBA), ethyldibromide (EDB) and 1,2-dichloroethane (1,2-DCA) in accordance with EPA ' Method 8260-Modified, respectively ' 3.0. FINDINGS Ground water elevations iiia fio%Tr ciueetions were uilened from.field data Hydrocaibon-.mpact to ground water was characterized from laboratory analytical data 3 1 GROUND WATER ELEVATION AND GRADIENT The average ground water elevation of the seven shallow ground water monitoring wells on 08 August 2001 was approximately 12 3 feet below mean sea level (msl),with the average depth of water at 20 0 feet below casing tops The ground water table occurred within the screened intervals of wells MW 7 and MW-8 During the August 2001 monitoring event, ground water was between 8 82 and 10 37 feet above the screened intervals in monitoring wells MW-1 through MW-5 Therefore, the five ground water monitoring wells were "drowned", and may not have yielded I samples fully representative of ground water conditions near the top of the saturated zone where fuel hydrocarbons would be expected to have the greatest impact The ground water table occurred approximately 40 feet above the screened interval of the deep well MW-6 fBased on data collected during the August 2001 monitoring event,ground water appears to be ridged • near the former UST area(Figure 3) The gradient was inferred to be flowing toward the northwest IAdvanced GeoEnvirunmentai,Inc I