Laserfiche WebLink
1 � , <br /> ' 15 November 2005 <br /> AGE-NC Project No 02-0926 <br /> ' Page 2 of 4 <br /> wells to achieve a minimum 80% recovery of the pre-purge water volume The samples from each <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, and <br /> 0 Total Lead in accordance with EPA method 6010B <br /> ' 3.0. FINDINGS <br /> ' 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 /> ' 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 41 55 feet below surface grade (bsg) Ground water elevation at the site <br /> ' ranged from 22 09 feet (MW-3) to 23 34 feet (MW-2) below mean sea level (MSL) The ground <br /> water gradient was calculated to be approximately 0 018 foot/foot (ft/ft) toward the north 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 22 July 2005 <br /> 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> TPH-g and BTEX were detected in the ground water sample collected from monitoring well MW-3 <br /> at concentrations of 270 micrograms per liter (µg/l), 10 µg11 benzene, 3 2 µg/l toluene, 3 7 µg11 <br /> • ethylbenzene, 11 2 µg/1 xylenes 1,2-DCA was detected in the ground water samples collected from <br /> Advanced GeoEnvironmental,Inc <br /> 1 <br />