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ori 1'i . Additionally groundwater samples were collected from monitoring wells MW1, MW2, MW4, MW6, and MW7 Groundwater samples were collected from the monitoring wells after stabilization of pH, electrical conductivity (EC), and temperature All wells monitored were purged and sampled according to Smith Technology's Quality Assurance/Quality Control Plan on file with the PHS/EHD A minimum of four casing volumes of water were removed from each sampled well A dedicated disposable bailer was used to collect each water sample Purge water was contained in labeled DOT approved 55 gallon drums and stored on site Field parameters and purged volumes are shown on well purge logs included in Attachment I LABORATORY ANALYSIS Free product samples collected from the passive skimmer in well MW2 were placed on ice and transported under chain-of-custody protocol to State-certified American Environmental Network (AEN) laboratory in Pleasant Hill, California (DHS Certification No 1172) Free product samples from well MW2 were analyzed for volatile organic compounds (VOCs) by EPA Method 8010, total petroleum hydrocarbons as diesel (TPHd) by EPA Method 8015M, pH, and flash polnt/'ignitabillty by EPA method 1010 There was however insufficient product volume present in the skimmer's reservoir to perform an analysis for reactivity The analyses performed were based on communications with PHS/EHD staff Groundwater samples from the monitoring wells were placed on ice and transported under chain- of-custody protocol to AEN laboratory Groundwater samples from wells MW 1, MW4, MW6, and MW7 were analyzed for TPHg and TPHd by EPA method 8015 modified, BTEX by EPA method 8020, and oxygenate fuel additives by EPA method 8260 The groundwater sample from well MW2 was analyzed for TPHg, TPHd, BTEX, and methyl tertiary butyl ether The groundwater sample from well MW2 was not analyzed for oxygenate fuel additives due to the presence of free product In this well ANALYTICAL RESULTS The free product sample from well MW2 did not contain detectable concentrations of VOCs or TPHd at or above the respective laboratory method detection levels However, the method detection levels were elevated due to dilution The pH of the free product sample was 7 8 and no flash was detected at or below 140 degrees Fahrenheit in this sample Results are summarized in Table 3 Groundwater samples from wells MW 1 and MW2 contained concentrations of benzene in excess of the State of California Maximum Contaminant Level (MCL) of 1 part per billion (ppb) No other petroleum constituents were detected above MCLs MTBE was detected in the water sample collected from well MW2 at a concentration of 8 ppb, however this concentration is below the State Advisory Level (OEHHA) of 30 ppb Oxygenate fuel additives were not detected to the remaining water samples Analytical results for groundwater are summarized in Table 2 Laboratory data sheets and chain of custody documentation are included as Attachment 11 • • 943341QUARTLWQR-1997 DOC 3 SMTH