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' 13 June 2001 AGE-NC Project No. 95-0185 ' Page 2 of 4 ' 2.2. COLLECTION OF GROUND WATER SAMPLES Ground water samples were collected from each well using new disposable plastic bailers. Each water sample was then transferred into one I-liter amber bottle and three 40-m1 volatile organic analysis(VOA)vials containing 0.5 ml 18%HCl as a sample preservative. The samples were then labeled and placed in a chilled container for transport under chain-of-custody to McCampbell ' Analytical, Inc. (MAI), a California Department of Health Services (DHS)-certified analytical laboratory. Each sample was analyzed for: ' Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d) in accordance with EPA Method 8015 Modified for gasoline and diesel fuel, respectively, ' • Purgeable aromatic compounds -benzene, toluene, ethylbenzene and total xylene (BTEX) with methyl tertiary butyl ether(MTBE) in accordance with EPA Method 8020 and • Oxygenated compounds and volatile organic compounds - di-isopropyl ether(DIPE), ethyl tertiary-butyl ether (ETBE), MTBE, tertiary-amyl methyl ether (TAME), tertiary butanol (TBA),methanol, ethanol,ethylene dibromide(EDB)and 1,2-dichloroethane(1,2-DCA)in ' • accordance with EPA Method 8260. ' 3.0. FINDINGS Ground water elevation, flow direction and gradient were determined from field data collected on ' I 1 April 2001; the contaminant impact to ground water was quantified by the ground water sample laboratory analytical data. 3.1. GROUND WATER GRADIENT AND FLOW DIRECTION During the April 2001 sampling event, the depth to ground water at the site ranged from 21.01 to 21.65 feet bsg. The depth to ground water and elevation collected from well MW-4 appears to ' affected by the presence of free-product. The thickness of the product was not properly measured. Therefore the relative ground water elevation from well MW-4 was discounted when preparing the ground water gradient map. Utilizing the other ground water elevation data, a ground water flow_ direction was developed similar to historical flow directions. The relative ground water elevation at the site ranged from 3 8.8 3 to 3 8.8 9 feet. The ground water ' flow direction determined during this monitoring event is toward the southeast with a hydraulic • gradient of 0.0005 feet/feet. The relative ground water elevations at the site are contoured on Figure 3. ,- Advanced GcoEnvironmental,Inc.