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1 <br />' 14 November 2002 <br /> AGE-NC Project No 95-0143 <br />' Page 2 of 4 <br />' 2 2 COLLECTION OF GROUND WATER SAMPLES <br /> Water samples were collected from each purged well using a new, disposable bailer and, upon <br />' retrieval,were transferred into 40-m1 EPA-approved VOA vials containing 0 5 ml 18%hydrochloric <br /> acrd as a sample preservative The samples were labeled and transported in a chilled container,under <br /> chain-of-custody protocol,to McCampbell Analytical,Inc (MAI), a DHS-certified laboratory The <br />' samples were analyzed for <br /> • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA <br />' Method 8015 modified, and <br /> • Benzene, toluene, ethylbenzene and total xylenes (BTEX) and methyl tertiary-butyl ether <br /> (MTBE) in accordance with EPA Method 8021 B <br /> 1 <br />' 3.0. FINDINGS <br /> Ground water elevation was calculated and flow direction was inferred from field data, the <br />' hydrocarbon impact to ground water was quantified from laboratory analysis <br />' 3 1 GROUND WATER ELEVATION AND GRADIENT <br /> During the September 2002 monitoring event, the average depth to ground water at the site during <br />' the September 2002 monitoring event was 17 15 feet bsg Ground water was within the screened <br /> intervals of wells MW-10,MW-15,MW-16,MW-17,MW-22,MW-23 and MW-24, ground water <br /> ranged from 0 01 feet to 5 63 feet above the screened interval in the other five monitoring wells <br />' The elevation of ground water in the twelve wells was calculated by subtracting the depth to water <br /> from the surveyed casing elevation (Table 1) The average ground water elevation was 7 71 feet <br />' below mean sea level (MSL), a decrease of 1 08 feet since the May 2002 monitoring event The <br /> inferred ground water flow direction was toward the northeast with a gradient of 0 002 foot/foot <br />' Ground water elevation contours for the September 2002 monitoring event are illustrated in Figure 3 <br /> 3 2 ANALYTICAL RESULTS OF WATER SAMPLES <br /> During the September 2002 monitoring event, TPH-g was detected in samples collected from <br />' monitoring wells MW-3, MW-6 and MW-9 at concentrations ranging from 190 µg/1 (MW-6) to <br /> 160,000 µg11 (MW-3) BTEX compounds were detected in the same wells at concentrations as high <br /> as 4,800 µg/1 benzene, 47,000 µg/1 toluene, 4,200 µg/1 ethylbenzene and 25,000 µg/1 xylenes, in <br /> IAdvanced GeoEnvironmental,[ne <br /> I <br />