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02 May 2003 <br /> AGE-NC Protect No 95-0142 <br /> Page 2 of 4 <br /> 2 2 GROUND WATER SAMPLE COLLECTION <br /> After allowing the monitoring wells to achieve a minimum of 80%recovery of the pre-purge water <br /> volume,water samples were collected from each well using the dedicated polyethylene bailers The <br /> water was then transferred into EPA-approved 40-millihter (ml) VOA vials containing 0 5 ml <br /> hydrochloric acid (18%) as a sample preservative The vials were labeled and placed In a clulled <br /> container for subsequent transport under chain-of-custody to McCampbell Analytical, Inc (MAI}, <br /> a State of California Department of Health Services (DHS) certified laboratory Ground water <br /> samples were analyzed for the following• <br /> • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA <br /> Method 8015 Modified and <br /> Benzene,toluene, ethylbenzene and total xylenes(BTEX)and the oxygenated fuel additives <br /> methyl tertiary-butyl ether (MTBE), di-isopropyl ether (DIPE), ethyl tertiary-butyl ether <br /> (ETBE),tertiary-amyl methyl ether(TAME)and tertiary butanol(TBA),methanol,ethanol, <br /> ethylene dibromide (EDB) and 1,2-dichloroethane (1,2--DCA) in accordance with EPA <br /> Method 8260 <br /> • <br /> 3.0. FINDINGS <br /> Ground water elevation, flow direction and gradient were determined from field data collected in <br /> March 2003 ,the contaminant impact to ground water was quantified by the ground water laboratory <br /> data <br /> 3 1 GROUND WATER GRADIENT AND DIRECTION <br /> Depth to ground water at the site ranged between 27 76 feet and 28 77 feet below the tops of the well <br /> casings The ground water elevation in the wells ranged from 15 70 feet (MW-1) to 16 37 feet <br /> (MW-2)below mean sea level(MSL) The average ground water elevation decreased approximately <br /> 127 feet since the previous monitoring event The elevation and ground water depth data is depicted <br /> in Table 1 <br /> During the March monitoring event, the general ground water flow direction In the shallow ground <br /> water table (vapor wells) was toward the northwest at an average hydraulic gradient of <br /> 0 009 foot/foot and less,ground water flow direction in the intermediate monitored water zone(wells <br /> MW-1, MW-2 and MW-3 ) was toward the northeast with an average hydraulic gradient of <br /> • 0 006 foot/foot (unchanged), while ground water flow direction in the deep monitored water zone <br /> Advanced GeoEnvironmental,Inc <br />