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, <br /> r ' <br /> ;6-46-` yJ P. <br /> 20 July 2005 - <br /> AGE-NC Project No °96-0235 '_ <br /> � Page 2 of 5 <br /> 22 COLLECTION AND ANALYSIS OF GROUND WATER SAMPLESIt <br /> It ' Water samples were collected from each purged well utilizing the discharge tube of the Waterra ' I <br /> {w� . r t { F a 11 « pry'=tAt <br /> } i ' Inertial pump or a new, dedicated disposable plastic bailer'after allowing the weils to achieve arf <br /> minimum'80% recovery of the pre-purge water volume Each water sample was transferred Into 4, <br /> 40-m1 volatile organic analysis (VOA) vials containing 0 5 ml 18% hydrochloric acid as a sample <br /> preservative and 1-liter amber bottles without preservative After collection, the,samples were <br /> properly 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 (DHS)- <br /> certified analytical laboratory, and were analyzed for f <br /> ' ' • <br /> fied as Total'petroleum hydrocarbons quanti `gasoline `(TPH-g) and total petroleum <br /> hydrocarbons as diesel'(TPH-d) in accordance with EPA Method 8015M'and <br /> • Benzene,toluene,ethylbenzene and total xylenes(BTEX)and the fuel additives di-Isopropyl ; <br /> ether(DIPE),ethyl tertiary-butyl ether(ETBE),methyl tertiary-butyl'ether(MTBE),tertiary- F <br /> amyl methyl ether (TAME), tertiary-butyl alcohol (TBA), 1,2-dibromoethane (EDB) and <br /> 1,2-dichloroethane (1,2-DCA) in accordance with EPA Method 8260B <br /> I• ' 1 I T 1 , n ' <br /> h <br /> I <br /> 11 <br /> 3.0. FINDINGS <br /> The hydrocarbon-Impact to ground water was quantified by laboratory analysis of the ground water <br /> samples Ground water elevation and gradient was determined by utilizing data collected from the <br /> - field _ x <br /> r Yr <br /> I <br /> 3 1 F r GROUND WATER GRADIENT AND FLOW DIRECTION <br /> Depths tound water ranged from 29 <br /> 'gro1 'feet to 18 64 feet below the tops of the well casings, t <br />' m ground water,was within the screened intervals of the shallow wells,but was approximately 12 5 feet <br /> .to 22 5 feet above the screened Interval-of the intermediate Wells and'47 feet above the screened <br /> Intervals of the deep webs <br /> , � � p <br />" The elevation of ground water in each,welI was calculated by subtractmg;the depth to ground water, <br />' from the surveyed casing elevations(Table 1) Ground water elevations at the site ranged from 10 08 <br /> feet(MW-4)to 1198 feet(MW-2)below mean sea level(MSL) The average ground water elevation <br /> at the site was approximately 1125 feet below MSL The averages ground water elevation In the t <br />' wells Increased by approximately 0 96 feet since the March 2005 ground water monitoring event i <br /> r <br /> I ' r Advanced GeoEnvironmentai,Inc <br />