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14, <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 TPHd by EPA method 8015 modified, and <br /> BTEX and methyl tertiary butyl ether (MTBE) by EPA method 8020 <br /> ANALYTICAL RESULTS <br /> The groundwater sample from well MW1 contained benzene (680 ppb), toluene (21 ppb), <br /> ethylbenzene (13 ppb), TPHg (1,500 ppb), and TPHd (3,300 ppb) MTBE was also reported ata <br /> concentration of 35 ppb, however this detection was not confirmed by laboratory EPA method <br /> 8260 Previous groundwater samples were analyzed for fuel oxygenates utilizing EPA method <br /> 8260 and none were detected indicating the recent detection of MTBE is most likely a false <br /> positive due to chromatogram interference <br /> The laboratory reported the TPH chromatogram patterns indicated both gas and weathered diesel <br /> are present in well MW1 This is consistent with the previous analytical data collected from this <br /> well in September and December 1998 <br /> The groundwater sample collected from well MW4 contained TPHd (280 ppb), and the <br /> groundwater sample collected from well MW6 contained TPHg (78 ppb) and TPHd (120 ppb) <br /> The groundwater sample from MW7 did not contain petroleum hydrocarbon constituents above <br /> laboratory method detection limits This is generally consistent with historical analytical data <br /> collected from this well beginning July 1994 <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 has been monitored and removed from MW2 monthly since a passive skimmer was <br /> installed in this well on June 27, 1997 During the First quarter 1999, a total of 0 05 liters of <br /> product were removed No free product was observed in the skimmer's reservoir during the <br /> March 1999 site visit <br /> To date a total of approximately 16 56 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 /> • presented in Table 3 <br /> 625811QUARTLYIIQR-1999 DOC 3 <br />