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I S <br /> 07 October 2003 <br /> AGE-NC Project No 95-0121 <br /> IPage 3 of 7 <br /> 2 4 LABORATORY ANALYSIS OF GROUND WATER SAMPLES <br /> Following collection and labeling,each groundwater sample was logged on a chain-of-custody form, w <br /> I placed in a chilled container and transported to Cal Tech Environmental Laboratories , a California " <br /> Department of Health Services (DHS)-certified laboratory, for analysis for <br /> I • Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d, <br /> respectively) by EPA Methods 8015M, <br /> • Benzene,toluene, ethyl benzene and xylene(BTEX)and methyl tert butyl ether(MTBE)by <br /> EPA Method 8021, <br /> • Di-isopropyl ether (DIPE), ethyl tert butyl ether (ETBE), tert amyl methyl ether (TAME), <br /> tertiary butanol (TBA) and confirmation of MTBE by EPA Method 8260B and <br /> • Ethylene dibromide (EDB) and 1,2-dichloroethane (1,2-DCA) by EPA Method 8260B <br /> I <br /> 30. FINDINGS <br /> Ground water elevation, flow direction and gradient were determined from field data collected <br /> on 12 June 2003 The contaminant impact to ground water was quantified by the ground water <br /> laboratory data <br /> 3 1 GROUND WATER ELEVATION AND GRADIENT <br /> I The depths to ground water in wells MW-1 through MW-9 and VW-I through VW-7 were measured <br /> at between 16 13 and 18 17 feet below the tops of well casings The ground water elevations were <br /> calculated to be between 10 01 feet (VW-7) and 11 19 feet (MW-5) below mean sea level The <br /> ground water elevation data obtained during this monitoring event are depicted in Figure 3 The <br /> inferred ground water flow direction, from within the lower sand level (confined)of the aquifer, for <br /> the area bound by wells MW-1 through MW-9 was inferred to be towards the northeast at an <br /> approximate gradient of 0 001 ft/ft or less, or approximately 5 feet per mile (Figure 3) <br /> On 12 June 2003 and on 16 June 2003, free-phase petroleum product was observed in well VW-1 <br /> However,the thickness of free-product petroleum product was reduced during the mitigation process <br /> by approximately one-half Therefore, the product appears to be properly dissipating during the <br /> manual product removal process <br /> IAdvanced GeoEnvtronmental,Inc <br /> , <br />