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' 28 April-1999 AGE-NC Project No. 95-0106 Page 2 of 4 chain of custody to McCampbell Analytical,Inca(MAI), a California Department of Health Services , (DHS)-certified analytical laboratory for analysis. The samples were analyzed for: •; Total petroleum-hydrocarbons quantified 'as-'gasoline'(TPH-g) 'in accordance with EPA Method 8015-modified;. , • Volatile aromatic compounds, specifically benzene;.toluene, ethylbenzene, and total xylene's (BTEX)with methyl tertiary butyl ether(MTBE) in accordance with EPA Method 8020, and ' • Oxygenated fuel additives: MTBE, tertiary butyl alcohol (TBA), di-isopropyl ether(PIPE)', ethyl tertiary butyl ether(ETBE).and tertiary.amyl methyl ether(TAME)in accordance with EPA Method 8260m. 3.0. FINDINGS ; Ground'water elevation and flow direction were calculated from'field data; h drocarbon-im act'to _ Y p ground water was inferred from laboratory analysis of the ground water samples.. 3.1.' GROUND WATER ELEVATION AND FLOW DIRECTION I The ground water elevation has increased an average 0.89 feet since the last monitoring event and, I _ _the average flow direction was-approximately N9°W.at a gradient. of approximately 0.009 ft/ft. Ground water elevation data.is presented in'Table 1; the contoured ground water.elevation data is -shown on Figure'3. 3.2. LABORATORY RESULTS OF GROUND.WATER SAMPLES ' Petroleum escr h drocarbon ,werdeteted in the ound water samples collected from monitorin wells .g.. Y g, p MW-1 and MW�4; MWA'is located cross-gradient from the former UST excavation'and MWA is ' located further north in the'down-gradient directiori.,TPH-g was detected at concentrations'of 1;200 ; micrograms per.liter,(kzg/l) and.1,800 ,ug/l, respectively, in samples frons the two wells. Benzene was detected at.610 jtg/1 and'80µg•11 in samples from MW-1 and MW-4, respectively. Other volatile aromatic compounds were detected at concentrations of 1 I µg/l and_17µg/1 toluene, and 47µg/1 and 100µg/1 xylenes in samples from MW-I-and MW-4,respectively. Ethylbenzene was detected,at 99 /41 in the sample from MW-4. Other analytes Were..not detected in the two.samples,.-'. Neither TPH-g.nor'BTEX were detected in tfie,ground water'sarriples from monitoring wells MW-2; ' Advanced GeoEnvironmental,-Ine.