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I r , r i 1 y I 23 November 1998 - AGE-NC Project`No 95-0142 ` Page 2 of 4 , - . ' water was stored on-site in labeled 55-gallon drums ' 22 GROUND WATER SAMPLE COLLECTION Water samples were collected from each purged well(MW-3, MW4,MW-5,VW-I through VW-4) ' ' using new,clean,disposable plastic bailers Immediately upon retrieval,the samples were transferred into EPA-approved 40-m1 VOA vials containing 0 5 milliliter hydrochloric acid (18%) as a sample preservative The vials were then labeled and placed in a chilled container The samples were ' transported in under chain-of-custody to McCampbell Analytical, Inc (MAI) a state-certified laboratory m Pacheco, California for analysis Ground water samples were analyzed In accordance 1 e with the following 1 • EPA Method 8015m for total petroleum hydrocarbons quantified as gasoline (TPH-g), • EPA Method 8020 for volatile aromatic hydrocarbons (benzene,toluene, ethyl-benzene and - - - total xyelens BTEX, �• 0 EPA Method 8260m for,di-isopropyl ether(DIPS),ethyl tertiary butyl ether(ETBE),methyl tertiary butyl ether(MTBE), tertiary amyl methyl ether(TAME) and tertiary butyl alcohol (TBA) 3.0.- FINDINGS The, ground water flow direction and gradient were calculated from the filed data The current ' distribution of dissolved petroleum hydrocarbons was inferred the laboratory analyses of the ground, water samples I 1 3 1 GROUNDWATER GRADIENT AND DIRECTION ; Depth to ground water at the site ranged from 25 73 feet to 26 80 feet below the well casing tops Between June and September the average,ground water elevation decreased 0 7 feet The relative ground water elevation data is depicted in Table I - The ground water elevation gradient for the water surfaces was calculated to be 0 0024 feet/feet or 12 9 feet/mile During the September monitoring event,the ground water flow direction and water surface appeared to be directed toward well MW4 The relative elevation of ground water surface at the site Is illustrated on Figure 3 Advanced Geo£nvnronmental,Inc.