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15 July 2002 <br />AGE -NC Project No 96-0232 <br />Page 9 of 21 <br />Ground water samples were collected at sampling ports located near the tops of extraction wells <br />EW -2, EW -4 through EW -8 and EW -10, each extraction well was allowed to be operational for at <br />least 30 minutes prior to collecting samples directly into the sample containers Ground water <br />samples were not collected from EW -9 due to a pump malfiuiction <br />3 3 LABORATORY ANALYSIS OF GROUND WATER SAMPLES <br />Each ground water sample was logged on a chain -of -custody form, placed in a chilled container and <br />transported to a California Department of Health Services (DHS) -certified laboratory for analysis <br />for <br />• TPH-g, TPH-d and TPH-mo by EPA Methods 5030/8015 Modified and 3550/8015 <br />Modified, respectively, <br />• BTEX and MTBE by EPA Method 8020, and <br />• Methanol, ethanol, 1,2 -DCA, EDB, TBA, DIPE, ETBE, TAME and MTBE by EPA Method <br />8260 Modified <br />34 FINDINGS <br />Ground water elevation, flow direction and gradient were determined from field data collected on <br />30 April, 22 May and 13 June 2002, the contaminant impact to ground water was quantified by <br />laboratory analysis of water samples collected on 13 and 14 June 2002 <br />3 4 1 Ground Water Elevation and Gradient <br />The depths to ground water were measured at between 10 25 feet (MW -1 OD) and 13 92 feet <br />(MW -9C) below the tops of the well casings on 30 April 2002, at between. 1129 feet (MW -10A) and <br />15 24 feet (MW -9A) below the tops of the well casings on 22 May 2002, and between 10 75 feet <br />(MW -1 OC) and 14 45 feet (MW -9A) below the tops of the well casings during the 13 June 2002 <br />monitoring event <br />Ground water elevations were calculated to be between 197 feet (MW- l OD) and 2 42 feet (MW -6B) <br />below mean sea level (MSL) on 30 April 2002, between 3 01 feet (MW -10A) and 4 03 feet <br />(MW -13B) below MSL on 22 May 2002, and between 2 47 feet (MW -1 OC) and 2 98 feet (MW -1) <br />below MSL on 13 June 2002 Ground water elevation at the site generally decreased an average <br />Advanced GenEnvironmentsi, Inc. <br />