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1 <br /> ' 15 August 2005 <br /> AGE-NC Project No 02-0926 <br /> Page 2 of 4 <br /> U <br /> well were transferred into three 40-milliliter(ml) volatile organic analysis (VOA)vials containing - <br /> 0 5 ml 18% hydrochloric acid solution as a sample preservative, one 1-liter amber bottle without <br /> preservative, and one 16-ounce plastic bottle The samples were labeled with the monitoring well <br /> designation,date,time of sampling,and the sampler's initials and transported in a chilled container <br /> under chain of custody to Cal Tech Environmental Laboratories (CTEL), a Department of Health <br /> Services-certified analytical laboratory, for analysis The samples were analyzed for <br /> • Total petroleum hydrocarbons quantified as gasoline TPH-g),diesel TPH-d ,and motor oil <br /> (TPH-mo) in accordance with EPA method 8015M, <br /> • Benzene,toluene,ethylbenzene,and total xylenes(BTEX)and fuel additives tertiary butanol <br /> (TBA), di-isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETBE), tertiary-amyl methyl <br /> ' ether (TAME), methyl tertiary-butyl ether (MTBE), 1,2-dibromoethane (EDB), and <br /> 1,2-dichloroethane (1,2-DCA) in accordance with EPA method 8260B <br /> 3.4. FINDINGS <br /> lie Ground water elevation and flow direction were inferred from field data, hydrocarbon-impact to <br /> ground water was quantified by laboratory analysis of the ground water samples <br /> 1 <br /> 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> The elevation of ground water in each of the monitoring wells was calculated by subtracting the <br /> depth to ground water from the surveyed relative casing elevations(Table 1) Depths to ground water <br /> ' averaged approximately 4199 feet below surface grade (bsg) Ground water elevation at the site <br /> ranged from 22 51 feet (MW-3) to 23 80 feet (MW-2) below mean sea level (MSL) The ground <br /> water gradient was calculated to be approximately 0 019 foottfoot(ft/ft)toward the northeast During <br /> ' this monitoring event,the ground water elevations were within the screened intervals of the wells <br /> Figure 3 illustrates the contoured ground water elevations as measured on 20 April 2005 <br /> ' R <br /> 32 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> ' TPH-g, benzene, toluene, and xylenes were detected in the ground water sample collected from <br /> monitoring well MW-3 at concentrations of 350 micrograms per liter(µg11), 14 µg11, 3 1 µg/l, and <br /> ' 4 3 µg11, respectively 1,2-DCA was detected in the ground water samples collected from wells <br /> MW-1 and MW-3 at concentrations of 19 µg/1 and 110 µg11, respectively A concentration map <br /> ' Advanced GeoEnwronmentai,Inc <br />