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V � <br /> • A S S O C I A T E S I N C <br /> LABORATORY ANALYSIS <br /> Groundwater samples from the monitoring wells were placed on ice and transported under chain- <br /> of-custody protocol to Sequoia Analytical laboratory Groundwater samples from wells MW1, <br /> MW4, MW6 and MW7 were analyzed for TPHg and total petroleum hydrocarbons as diesel <br /> (TPHd) by EPA method 8015 modified, and BTEX and methyl tertiary butyl ether (MTBE) by <br /> EPA method 8020 <br /> ANALYTICAL RESULTS <br /> The groundwater sample collected from well MW1 contained benzene (675 ppb), ethylbenzene <br /> (21 7 ppb), xylenes (11 4 ppb), TPHg (2,010 ppb), TPHd (1,280 ppb), and MTBE (1,560 ppb) <br /> The laboratory reported the chromatogram patterns indicated both weathered gas and diesel are <br /> present in well MW 1 along with unidentified hydrocarbons The MTBE detected in this sample <br /> was not confirmed by laboratory EPA method 8260 <br /> Previous groundwater samples were analyzed for fuel oxygenates utilizing EPA Method 8260 <br /> and none were detected, indicating the reported MTBE concentration is most likely a false <br /> positive due to chromatogram interference This is consistent with historical analytical data <br /> obtained from this well <br /> The groundwater sample from MW4 contained benzene (6 73 ppb), TPHg (230 ppb) and TPHd <br /> (329 ppb), while the samples collected from wells MW6 and MW7 contained only TPHd at <br /> concentrations of 144 ppb and 52 4, respectively The laboratory reported the chromatogram <br /> patterns indicated an unidentified hydrocarbon (C9-C24) is present in wells MW4 through MW7 <br /> This is generally consistent with historical analytical data obtained from these wells <br /> Analytical results for groundwater are summarized in Table 2 Laboratory data sheets and chain <br /> of custody documentation are included as Attachment 2 <br /> FREE PRODUCT REMOVAL <br /> Free product was been monitored and removed from MW2 on a monthly basis from the time a <br /> passive skimmer was installed in this well on June 27, 1997 until December 1999 Due to the <br /> minimal amount of free product being recovered (<Q 5 liters per quarter) in comparison to the <br /> relatively large capacity of the skimmer's recovery reservoir (>2 liters), free product was <br /> removed only once during the reporting period, on March 24, 2000 During the First quarter <br /> 2000, a total of 0 15 liters of product were removed <br /> • To date a total of approximately 17 04 liters of product have been removed from the skimmer <br /> placed in MW2 A summary of product volume removed and previous product analytical data is <br /> 6258RQUAR`rLY11QR-2000 DOC 3 <br />