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' 18 July 2005• , ' . AGE-NC.ProjectNo. 95-0106. Page 2,of 4' : • .. V . The samples were transported. in `a -chilled. container under chain of custody 'to Cal Tech Environmental Laboratories (CTEL), a State,of California Department of Health Services (DHS)-"'' certified analytical laboratory, and analyzed'fo'- . • Total petroleum hydrocarbons quantified as .gasoline. (TAH-g). in accordance with EPA Method 8015-Modifled; - ' 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 5.7 feet(MW-4)to 7.11 feet(MW-3). The average ground water elevation was approximately 32.93 feet above mean sea level (MSL), increasing approximately 0.7 feet since the September 2004 monitoring event. The water table-appears as a northerly plunging 'ridge; the 'east and, west limbs of the, ridge flow`toward the northeast and northwest,respectively;at a gradient of approximately 0.005 foot/foot(ft/ft),while the f low gradient at the center of the ridge is approximately 0.003 ft/ft toward the north. Ground'water elevation data ' is presented'in Table 1 and,the contoured-ground water elevation data i5 shown on Figure 3. 1. ' 3.2. ANALYTICAL RESULTS OF 'GROUND WATER SAMPLES TPH-g was detected at concentration of 3,600`mi&ograms.perliter ([g/1) in,the sample.collected '. from well MW-4. ' BTEX;compounds were detected in the samples collected from wells MW-1 and MW-4 at the following concentrations: 12, µg/l (MW-1) and. 38 µg/1 (MW-4) benzene, 3.2 µg/l (MW-1) and 5.6 µg11 (MW-4).toluerie, 69 pg/1 (MW-4) ethylbenzene and 15 µg/1 (MW-4) xylenes. ' r Advanced GeoEnvironmental,Inc.