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r � <br /> 16 <br /> ANALYTICAL METHODS AND RESULTS <br /> Laboratory ,Analyses <br />' Groundwater samples were delivered to Creek Environmental Laboratories, Inc , a Caltrans-approved <br /> and California-certified analytical laboratory, for the analyses of TPHg and TPHd following EPA Test <br /> Method 8015, BTEX following EPA Test Method 8020 and fuel oxygenate compounds (FOCs) <br />' including MTBE, tert-amyl methyl ether (TAME), ethyl tert-butyl ether (ETBE), di-isopropyl ether <br /> (DIPE) and tert-butanol (TBA) following EPA Test Method 8260 Groundwater analytical results are <br /> summarized on Table 1 Laboratory reports and chain-of-custody documentation are presented in <br /> Appendix C <br /> Groundwater Analytical Results <br /> TPHg was detected in samples collected from wells MW-2, VW-1 and VW-2 at concentrations of <br /> 1,000, 130 and 9,900 µg/l,respectively TPHd was detected in the groundwater samples collected from <br /> wells MW-2, MW-3 and VW-2 at concentrations of 370, 70 and 2,100 gg/1, respectively Benzene was <br />' detected in groundwater samples collected from wells MW-2 and VW-2 at concentrations of 140 and <br /> 2,800 µg11, respectively Toluene, ethylbenzene and total xylenes were also detected in the samples <br /> collected from wells MW-2 and VW-2 at concentrations ranging from 20 gg/l (toluene - VW-2) to 660 <br /> µg/l (total xylenes -VW-2) MTBE was detected in one sample, VW-2, at 74 pg/1 TAME, DIPE, TBA <br /> and ETBE were not detected above their respective laboratory method detection limits in each of the <br /> groundwater samples collected TPHg, TPHd, benzene, and MTBE concentrations for the Second <br /> Quarter - 2003 monitoring event are depicted on Figure 3, Petroleum Hydrocarbons in Groundwater - <br /> June 2003 <br />' CONCLUSIONS AND RECOMMENDATIONS <br /> The highest concentrations of dissolved phase petroleum hydrocarbons appear to be limited to the <br /> immediate vicinity of the former UST excavation area (monitoring wells MW-2, VW-1 and VW-2) <br />' Pending site closure evaluation by the Central Valley Regional Water Quality Control Board <br /> (CVRWQCB),the next quarterly monitoring event is scheduled for September 2003 <br /> 1 <br /> Protect No 58475-06-24F -3- July 16,2003 <br />