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10 November 2003 <br /> AGE-NC Project No 97-0249 <br />' Page 3 of 8 <br /> Ground water sample collection from domestic water well DW-1 was achieved by opening a valve <br /> from the water well's outlet sampling port and allowing the well pump to turn on and operate for a <br /> minimum of 15 minutes to purge the well, a sample was collected directly from the running water <br />' into the above sample containers <br />' 2 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 /> • Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d, <br />' respectively) by EPA Methods 5030/8015Cm, <br /> • Benzene,toluene,ethylbenzene and xylene(BTEX)and methyl-tertiary butyl ether(MTBE) <br />' by EPA Method 8021B, <br /> • 1,2-Dichloroethane (1,2-DCA), ethylene dibromide (EBD), tertiary butanol (TBA), di- <br /> isopropyl.ether(DIPE), ethyl tert butyl ether(ETBE) and tert amyl methyl ether(TAME)by <br />' EPA Method 8260B <br />' 3.0. FINDINGS <br />' Ground water elevations, general flow direction and the estimated gradient were determined from <br /> field data collected on 15 September 2003, the contaminant impact to ground water was quantified <br /> by laboratory analysis of water samples collected on 15, 16 and 17 September 2003 <br /> 3 1 GROUND WATER ELEVATION AND GRADIENT <br />' The 15 September 2003 ground water elevation at wells MW-1 through MW-12 were calculated by <br /> subtracting the measured depth to ground water from the surveyed casing elevation The ground <br />' water elevation data collected from the site was plotted for the informal hydrogeologic flow units <br /> as defined in AGE'S CPT Site Investigation - Fourth Quarter 2001 (dated 15 March 2002) The <br /> depth to ground water measurements vaned from the purged wells between 11 79 feet(MW-6) and <br />' 15 07 feet (MW-2) below the top of well casings, ground water elevation was calculated to be <br /> between 4 93 feet(MW-11 B and MW-I I E)and 5 36 feet(MW-5)below mean sea level Generally, <br /> ground water elevation at the site decreased an average 0 45 feet between the June 2003 and the <br />' September 2003 ground water monitoring events <br /> Advanced GeoEnvironmental,Inc <br />