ARCHIVED REPORTS XR0006139 - Laserfiche WebLink

Home Browse Search

' 03 February 2003 AGE-NC Project No 98-0465 Page 2 of 4 22 COLLECTION OF GROUND WATER SAMPLES Water samples were collected from the purged wells using new disposable plastic bailers after allowing the wells to achieve a minimum 80%recovery of the pre-purge water volume Each water sample was transferred into three 40-m1 VOA vials containing 0 5 ml 18% hydrochloric acid as a sample preservative and one 1-liter amber bottle with no sample preservative After collection, the samples were properly labeled,placed in a chilled container and transported under chain-of-custody to McCampbell Analytical, Inc (MAI) for analysis The samples were analyzed for • Total petroleum hydrocarbons quantified as gasoline (TPH-g) and diesel (TPH-d) in accordance with EPA Method 8015 Modified, and • Benzene, toluene, ethylbenzene and xylenes (BTEX) and fuel oxygenates methyl tertiary- butyl ether (MTBE), di-isopropyl ether (DIPE), ethyl tertiary-butyl ether(ETBE), tertiary- amyl methyl ether (TAME), and tertiary butanol (TBA) in accordance with EPA Method 8260B to 30. FINDINGS Ground water elevation, flow direction and gradient were determined from field data collected on ' 21 November 2002, the contaminant impact to ground water was quantified by the laboratory analytical data r3 1 GROUND WATER GRADIENT AND FLOW DIRECTION At the time of the November 2002 sampling event, depths to ground water ranged from 12 27 feet to 13 29 feet below the tops of the well casings During this monitoring event,the ground water level in the wells was approximately 8 13 to 8 33 feet below the tops of the well screens, indicating that ' the wells are screened properly and yield representative shallow ground water samples Ground water elevations at the site ranged from 9 53 feet below mean sea level(MSL)in wells MW3 and MW4 to 9 65 feet below MSL in well MW2 (Table 1) The relative ground water elevation at the site decreased an average of 0 9 feet between the August 2002 and November 2002 monitoring events Site ground water flow direction was northeast at an average gradient of 0 001 feet/feet Figure 3 ' illustrates the contoured ground water elevations as measured on 21 November 2002 ' Advanced GeoEnwronmental,Inc