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1 <br />' 20 June 2001 <br /> • AGE-NC Project No 99-0624 <br />' Page 2 of 4 <br />' 2 2 COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES <br /> Water samples were collected from each monitoring well using new disposable bailers after allowing <br />' the wells to achieve a minimum 80% recovery of the pre-purge water volume The samples were <br /> transferred into laboratory-supplied 40-m1 EPA-approved VOA vials containing 0 5 ml 18% <br />' hydrochloric acrd as a sample preservative The sample vials were then labeled with the monitoring <br /> well designation,date,time of sampling and the sampler's initials The samples were transported in <br /> a chilled container under chain of custody to McCampbell Analytical, Inc (MAI), a California <br />' Department of Health Services(DHS)-certified analytical laboratory for analysis The samples were <br /> analyzed for <br />' • Total petroleum hydrocarbons quantified as gasoline (TPH-g) In accordance with EPA <br /> Method 5030/8015 Modified, <br /> • Volatile aromatic compounds - benzene, toluene, ethylbenzene, and total xylenes (BTEX) <br />' and methyl tertiary butyl ether(MTBE) in accordance with EPA Method 8020, and <br /> • Fuel oxygenates - tertiary butanol (TBA), di-isopropyl ether (DIPE), ethyl tert-butyl ether <br />' (ETRE), tert-amyl methyl ether (TAME), and MTBE in accordance with EPA Method <br /> 8260M <br /> 3.0. FINDINGS <br />' The ground water elevation in each well was determined by subtracting the measured depths-to- <br /> water from the surveyed casing elevations and are presented in Table 1 Ground water flow direction <br />' was determined by contouring the ground water elevations on a scaled site plan (Figure 2) <br /> Hydrocarbon-Impact and MTBE-impact to ground water were assessed from laboratory analysis of <br /> the ground water samples <br /> I ' <br /> 3 1 GROUND WATER ELEVATION AND GRADIENT <br />' Depths to ground water ranged from 50 79 feet to 51 88 feet below the tops of the well casings <br /> Ground water elevations at the site ranged from 12 34 feet (MW-4) to 12 61 feet (MW-1) below <br />' mean sea level The top of the saturated zone occurred within the screened intervals of all the <br /> monitoring wells <br />' The ground water flow direction was determined by contouring the ground water elevation data The <br /> . ground water underlying the site was inferred to have an average gradient of 0 003 ft/ft and flowed <br /> I <br /> Advanced GeoEnvironmental,Inc <br />