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jJ n <br /> 5 <br />' 01 June 2006 <br /> • AGE-NC Protect No 02-0977 <br />' Page 2 of 5 <br />' 22 COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES <br /> Water samples were collected from each purged well using a Watera hydrohft pump and dedicated <br />' tubing after allowing the wells to achieve a minimum 80%recovery of the pre-purge water volume <br /> Each water sample was transferred into three 40-m1 volatile organic analysis(VOA)vials containing <br /> 0 5 ml 18%hydrochloric acid as a sample preservative After collection, the samples were properly <br />' labeled, placed in a chilled container and transported under chain of custody to Cal Tech <br /> Environmental Laboratories (CTEL), a State of California Department of Health Services-certified <br /> analytical laboratory The samples were analyzed for <br />' 0 Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA <br /> Methods 8015M, <br />' 0 Benzene, toluene, ethylbenzene and total xylenes (BTEX) in accordance with EPA Method <br /> 8260B, and <br />' 0 Fuel additives di-isopropyl ether (DIPS), ethyl tertiary-butyl ether (ETBE), methyl tertiary- <br /> butyl ether (MTBE), tertiary-amyl methyl ether (TAME), tertiary butanol (TBA), <br /> 1,2-dichloroethane (1,2-DCA) and ethylene dibromide (EDB) in accordance with EPA <br /> lie Method 8260B <br />' 3.0. FINDINGS <br />' Ground water elevation, flow direction, and gradient were determined from field data The <br /> contaminant impact to ground water was quantified by the laboratory analytical data <br />' <br /> 31 GROUND WATER GRADIENT AND DIRECTION <br />' At the time of the March 2006 sampling event, depths to ground water ranged from 5148 feet to <br /> 52 61 feet below the tops of the well casings(TOC) Ground water elevations at the site ranged from <br />' 13 18'feet below mean sea level (MSL)in wells MW-4 and MW-7 to 13 44 feet below MSL in well <br /> MW-5 (Table 1) During this monitoring event, the ground water levels in wells MW-1 through <br /> MW-6 and MW-8 were approximately six to seven feet below the tops of the well screens,indicating <br /> I that the wells are screened properly to yield representative shallow ground water samples,the ground <br /> water elevation was approximately 28 feet above the screen interval of MW-7, and is representative <br /> of deeper ground water conditions The ground water elevation at the site increased approximately <br /> I2 35 feet between the December 2005 and March 2006 monitoring events <br /> Advanced GeoEnvironmental,Inc <br />