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1 , <br />' 27 February 2004 <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 purged well using a Watera hydrolift 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 /> • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA <br /> Methods 5030/8015M, <br />' Benzene, toluene, ethylbenzene and xylenes (BTEX) in accordance with EPA method <br /> 8260B, and <br />' Fuel additives dl-isopropyl ether(DIPE), 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 /> 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 /> 1 <br /> 31 GROUND WATER GRADIENT AND DIRECTION <br />' At the time of the February 2004 sampling event, depths to ground water ranged from 52 47 feet to <br /> 53 80 feet below the tops of the well casings Ground water elevations at the site ranged from <br /> 14 3 feet below mean sea level (MSL) in well MW-4 to 15 47 feet below MSL in well MW-6 <br /> (Table 2) During this monitoring event,the ground water levels in wells MW-1 through MW-4 and <br /> MW-6 were at least eight feet below the tops of the well screens, indicating that the wells are <br />' screened properly to yield representative shallow groundwater samples The groundwater elevation <br /> at the site increased approximately 0 84 feet between the November 2003 and,February 2004 <br /> monitoring events <br /> Ground water on 23 February 2004, depths to ground water ranged from 52 47 feet to 53 60 feet <br /> below the tops of the well casings Ground water elevations at the site ranged from 14 1 feet below <br />' MSL in well MW-4 to 14 30 feet below MSL in well MW-1 (Table 2) The ground water was <br /> Advanced GeoEnvironmental,Inc <br />