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• 10 March 2000 AGE-NC Project No. 95-0109 Page 2 of 4 2.2. COLLECTION OF GROUND WATER SAMPLES The depth to water was remeasured after purging to ensure a minimum of 80 per cent recharge prior to sampling. Water samples were collected from each purged well using disposable plastic bailers. Immediately upon retrieval, the samples were transferred into 40-m1 EPA-approved VOA vials containing 0.5ml 18%hydrochloric acid as a sample preservative. The samples were labeled, stored on ice, and transported in a chilled container, under chain-of-custody, to McCampbell Analytical, Inc. (MAI), a State of California Department of Health Services (DHS)-certified analytical laboratory. All samples were analyzed for: • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Methods 5030/8015m; • Volatile aromatic compounds: benzene, toluene, ethylbenzene and xylenes (BTEX) and methyl tertiary-butyl ether (MTBE) in accordance with EPA method 80201602; and • Volatile organic compounds with fuel oxygenates: di-isopropyl ether(DIPE), ethyl tertiary- butyl ether(ETBE),MTBE,tertiary-amyl methyl ether(TAME) and tertiary butanol (TBA) in accordance with EPA Method 8260/8260m. Samples collected from MW-9 and MW-14 were also transferred into one-liter amber bottles without added preservative. These samples were transported to A. Keith Kaufman in Culver City and analyzed for physicochemical properties and microbiological enumeration. 3.0. FINDINGS Ground water elevation and flow direction were calculated from field data; hydrocarbon-impact to ground water was inferred from laboratory analysis of the ground water samples. 3.1. GROUND WATER GRADIENT AND DIRECTION The depth to ground water ranged from 50.62 feet bsg north of the site to 53.23 feet bsg south of the site during the January 2000 monitoring event. The data indicates an average 1.58-foot increase of ground water elevation between September 1999 and January 2000. Ground water elevation contours, based upon data collected on 18 January 2000, are depicted in Figure 3. The inferred ground water flow direction is toward the south. The ground water depression and localized high previously observed west of the site was not evident during the January 2000 monitoring event. Ground water elevations are summarized on Table 1. Advanced GeoEnviron mental,Inc.