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' 17 February 2006 . AGE-NC Project No 98-0511 ' Page 2 of 4 ' minimum 80% well-volume recharge had been achieved prior to sampling Water samples were collected from each purged well using dedicated,disposable plastic bailers Each water sample was transferred into three laboratory-supplied, 40-milliliter (ml) volatile organic analysis (VOA) vials ' containing 0 5 ml 18% hydrochloric acid solution as a sample preservative After collection, the samples were properly labeled,placed in a chilled container,and transported under chain of custody to Cal Tech Environmental Laboratories (CTEL), a California Department of Health Services ' (DHS)-certified analytical laboratory, and analyzed for • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA ' Method 8015M and • Benzene, toluene, ethylbenzene, and total xylenes (BTEX) and fuel additives di-isopropyl ' ether(DIPE),ethyl tertiary-butyl ether(ETBE),methyl tertiary-butyl ether(MTBE),tertiary- amyl methyl ether (TAME), tertiary-butyl alcohol (TBA), 1,2-dibromoethane (EDB), and 1,2-dichloroethane (1,2-DCA) in accordance with EPA Method 8260B 3.0. FINDINGS • Ground water elevation and flow direction were determined from field data collected on 07 November 2005 Hydrocarbon impact to ground water was inferred from laboratory analysis of ground water samples 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION For the November 2005 ground water monitoring event,the elevation of ground water in each well was calculated by subtracting the depth to ground water from the surveyed casing elevation (Table 1) Depths to ground water ranged from 16 33 feet(MW-5)to 16 98 feet(MW-1)below the I tops of the well casings Ground water elevations at the site ranged from 1 16 feet above mean sea level (MSL) in well MW-1 to 1 55 feet above MSL in well MW-4 Ground water elevation data for monitoring wells MW-5 and MW-8 was not included in the calculations, the well boxes were replaced and raised to prevent surface water and soil from collecting inside An additional short length of casing was also added to the well heads for easier access Ground water at the site was inferred to flow toward the southwest on the southern portion of the site and radially inward toward a depression in the potentiometric surface near well MW-1 on the northern portion of the site, calculated gradients ranged between 0 004 foot/foot (ft/ft) and 0 0009 ft/ft Ground water flow direction near the former UST area is consistent with flow directions • observed during previous monitoring events {Figure 3} IAdvanced GeoEnvironmental,Inc