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Report,Groundwater-quality Monitoring—July 29,2002: 7500 West Eleventh Street, Tracy, CA. Page 9 <br /> analytes. <br /> Analyte Method of Analysis <br /> Total Petroleum Hydrocarbons EPA Method 8015M <br /> (quantified as Diesel) <br /> Total Petroleum Hydrocarbons EPA Method 8260FAB <br /> (quantified as Gasoline) <br /> Benzene EPA Method 8260FAB <br /> Toluene EPA Method 8260FAB <br /> 1 Ethylbenzene EPA Method 8260FAB <br /> ;i <br /> Total Xylene Isomers EPA Method 8260FAB <br /> ` 1 tertiary-Butyl alcohol EPA Method 8260FAB <br /> Methyl-tertiary butyl ether EPA Method 8260FAB <br /> Di-isopropyl ether EPA Method 8260FAB <br /> Ethyl tertiary-butyl ether EPA Method 8260FAB <br /> -' tertiary-Amyl methyl ether EPA Method 8260FAB <br /> # 1,2 Dichloroethane EPA Method 8260FAB <br /> STL is certified to perform the specified analyses by the California Department of Health <br /> Services (DHS). <br /> The results of the analyses of samples of groundwater are presented in Table 2, which <br /> also includes the results of analyses of groundwater samples recovered from the previous <br /> sampling rounds. <br /> Comparing results of analyses of samples of groundwater recovered on July 29, 2002 <br /> ._: with those from April 11, 2002, it is noted that the concentrations of diesel-range <br /> hydrocarbons in the groundwater sample recovered from monitoring well MW-3 rose <br /> from 200 wglL to 490 µg/L and the gasoline-range hydrocarbons rose from 330 gg/L to <br /> 4,800 gg/L with commensurate significant increases in the concentrations of the BTEX <br /> compounds and MTBE. MW-3 is a short distance down gradient from the former location <br /> of the fueling station's pump islands where the preponderance of the leakage of fuels to <br /> the subsurface had occurred. Similar increases, but of lesser less magnitude, were seen in <br /> {: 1 the results of the analyses of the sample recovered from Monitoring Well MW--4 on July <br /> sic <br />