ARCHIVED REPORTS XR0000760 - Laserfiche WebLink

Home Browse Search

i 31 October 2005 . AGE-NC Project No.�95-01.06 Page 2 of 4 _ The'.samples: were' transported in a chilled 'container under chain' of custody to Cal Tech ' ,I Environmental Laboratories (CTEL), a State of California Department of Health Servkes,'(DHS)- certified analytical laboratory, and analyzed for: . ' Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Method'80157Modified'; " ` Benzene, toluene, ethylbenzene and xylenes°(BTEX); and fuel.additives methyl tertiary- butyl-ether(MTBE),tertiary butyl alcohol(TBA),di-isopropyl ether(DIPE),ethyl'tertiary butyl ether(ETBE),tertiary-amyl methyl ether(TAME), 1,2-dibromoethane(EDB),and 1,2- ' ' dichloroethane (1,2-DCA) in accordance with EPA Method 8260B. 3.0. -FINDINGS ; Ground water elevation and-flow direction were inferred from field data. The hydrocarbon-impact ' to ground water was quantified by laboratory analysis of the ground water samples-. ' , 3.1. GROUND WATER ELEVATION AND FLOW DIRECTION- ' The'relative depth to ground water ranged from 5..92 feet(MW=2)to 6.94 feet(MW-3).The average ground.water elevation was approximately 32.87'feet..above mean sea level (MSL), decreasing approximately'0.64 feet since the March 2005 monitoring event..The water table appears,to flow north to northwesterly with a gradient between 0.006,ft/ft•and 0.011, ft/ft and flow towards the '!southwest off-site (MW-6)with a gradient of 0.016 ft/ft. Ground water elevation data is'presented in Table 1 and the contoured ground water elevation data is shown on-Figure 3_. .31.2. ANALYTICAL RESULTS OF GROUND WATER-SAMPLES TPH-g•was detected in groundwater samples at concentration of 120 micrograms per liter (µg11). (MW-1) and 500 µg/l (MW 4). BTEX compounds were also detected in the samples collected from wells MW-1 and MW.4 at the. ' following concentrations: 12 µg/1-(MW-1) and 27 µg/1;,(MW-4) benzene;.19 µg/1 (MW-1) and 4.4 µg/l (MW-4) toluene;�,3.0 µg/1 (MW-1)and 53''µg/1 (MW-4) ethylbenzene and 21.8 µg/l (MW-1) and 16.6 µg/l (MW-4) xylenes. ' Advanced GeoEnvironmerital,Inc.