ARCHIVED REPORTS XR0007603 - Laserfiche WebLink

Home Browse Search

' 12 February 2002 AGE-NC Project No 95-0135 ' Page 2 of 4 1v Water samples were collected one hour after well evacuation from each monitoring well utilizing ' the dedicated, disposable bailers The samples were transferred into 40-m1 EPA-approved volatile organic analysis (VOA) vials containing 0 5 ml hydrochloric acid (18%) as a sample preservative The samples,were transported in a chilled container, under chain-of-custody, to McCampbell ' Analytical Inc (MAI) of Pacheco, a State of California Department of Health Services (DHS)- certified laboratory, for analytical analysis The samples were analyzed for ' & Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Method 8015 Modified, • Benzene,toluene,ethyl benzene and total xylenes(BTEX)in accordance with EPA Method 8020, and • Oxygenating compounds including methyl tertiary-butyl ether(MTBE),tertiary-butyl alcohol (TBA),di-isopropyl ether(DIPE),ethyl tertiary-butyl ether(ETBE)and tertiary-amyl methyl ether(TAME),methanol, ethanol, ethylene dibromide (EDB) and 1,2-dichloroethane (1,2- DCA) in accordance with EPA Method 8260 Modified • 3.4. FINDINGS Ground water flow direction and gradient were inferred from field data,the petroleum hydrocarbon impact on ground water was quantified by the results of laboratory analysis 3 1 GROUND WATER ELEVATION AND GRADIENT ' During the October 2001 monitoring event, depths to ground water in wells MW-1 through MW-3 were measured between 25 48 and 26 95 feet below the tops of the well casings The water table has decreased in elevation approximately 182 feet between April and October 2001 The ground water table elevations were calculated to be between-13 56 feet and -13 85 feet below mean sea level During the October monitoring event the shallow ground water underlying the site flowed to the northeast under a gradient of 0 002 ft/fl The ground water elevation data for wells MWA B through MW-3B (water table wells) during the April 2001 ground water monitoring event is depicted on Figure 3 ry I , Advanced GcoEnvironmental,Inc I