Laserfiche WebLink
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 TPHd by EPA method 8015 modified, and <br /> BTEX and methyl tertiary butyl ether(MTBE) by EPA method 8020 <br /> ANALYTICAL RESULTS <br /> Analytical results indicate the highest concentrations of dissolved total petroleum hydrocarbons <br /> are present in the area of MW1 and MW2 where TPHg and/or TPHd were detected at 1,300 ppb <br /> to 7,720 ppb Similarly, reported BTEX concentrations were also highest in these wells, where <br /> benzene was detected at 342 ppb and 158 ppb, respectively <br /> Total petroleum hydrocarbons were detected in perimeter monitoring wells MW3 (76 6 ppb), <br /> MW4 (95 ppb), MW5 (66 ppb), and MW6 (74 ppb) However, these concentrations are less than <br /> twice the laboratory method detection limit of 50 ppb <br /> `• With the exception of MW3, where benzene was detected at 1 81 ppb, no BTEX constituents <br /> were reported in water samples collected from the perimeter wells, including wells MW3, MW4, <br /> MW5, MW6, and MW7 <br /> Methyl-tertiary-butyl-ether (MTBE) was reported in the water samples collected from wells <br /> MW1 (22 5 ppb) and MW2 (18 2 ppb), however these detection were not confirmed by <br /> laboratory EPA method 8260 Previous groundwater samples were analyzed for fuel oxygenates <br /> utilizing EPA Method 8260 and none were detected, indicating the reported MTBE concentration <br /> is most likely a false positive due to chromatogram interference <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 Third quarter 1999, a total of approximately <br /> 0 02 liters of product were removed <br /> To date a total of approximately 16 80 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 /> 625811QUARTLYI3QR-1999 DOC 3 <br />