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. Mr Jeffrey Wong Page 2 Prior to sampling, wells MW 1 through MW4 were purged of a minimum of three well casing volumes During the purging process physical parameters (temperature, pH and electrical conductivity) were measured in each respective well, and well MW 1 went dry once Groundwater samples were collected after physical parameter stabilization, and at least 80% water level recovery of initial depth to water measurements Subsequently the samples were placed in an ice chest cooled to a temperature of approximately 4°C Purgewater was contained in appropriately labeled DOT-approved 55-gallon drums, and is currently being stored onsite pending proper disposal options Purge logs are included in Attachment A Groundwater samples were delivered under chain of custody protocol to Argon Laboratories (ELAP #2359) Analysis consisted of gasoline oxygenate additives, 1,2-DCA and EDB using EPA method 8260, BTEX using EPA method 8020, and TPHg using modified EPA method 8015 As requested by PHS/EHD, Ground Zero has obtained permission from U-Haul to monitor and sample well MW7 in the future Due to an oversight, this well was not monitored and sampled during this sampling event but will be included during the next sampling event • GROUNDWATER ANALYTICAL RESULTS TPHg was detected in the samples from each site monitoring well Benzene was detected in the samples from monitoring wells MW 1, MW2, and MW4 Benzene was not detected in monitoring well MW3 for the first time TPHg concentrations ranged from 130 parts per billion (ppb) to 160,000 ppb, and benzene concentrations ranged from <0 5 ppb to 15,000 ppb in wells MW3 and MViWI, respectively 1,2-DCA was detected in all wells except MW3 at concentrations ranging from 150 ppb in well MW4 to 700 ppb in well MW 1 Gasoline oxygenate additives and EDB were not detected in the samples from any monitoring well Analytical results are summarized in Table 2 Attachment B contains laboratory reports and chain of custody documentation SUMMARY • Groundwater flow radiated from an apparent groundwater mound near well MW 1 • TPHg, BTEX and 1,2 DCA concentrations were generally lower than those recorded during previous sampling events and appear to be decreasing • Concentrations of gasoline oxygenate additives remained at non-detectable levels in all wells EDB was not detected in wells MW1 through MW4 1,2 DCA was not detected in well MW3 for the fourth consecutive event Harryslrepor[slgmrWgm2001 duc