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a • A S S O C I A T E S I N C concentrations of petroleum hydrocarbons Field activities and analytical results were detailed in ATC's Summary Report of Additional Investigation, dated October 19, 1998 In April 2000, ATC personnel supervised the advancement of three soil borings at the site, S138 through SB 10 Soil borings were advanced using a truck mounted Geoprobe® narrow diameter rig employing direct push technology Soil and groundwater samples were collected and analyzed from each boring and were found to contain no detectable concentrations of total petroleum hydrocarbons as gasoline (TPHg), total petroleum hydrocarbons as diesel (TPHd), benzene, toluene, ethylbenzene, xylenes (BTEX), or methyl tertiary butyl ether (MTBE) Field activities and analytical results were detailed in ATC's Summary Report ofAdditional Subsurface Investigation, dated September 7, 2000 In June 2000, ATC personnel supervised the advancement of three additional soil borings, MW4 through MW6 The borings were advanced using hollow stem auger drilling Approximately ten inches of free product was discovered in boring MW4 at a depth of 20 feet bgs In accordance with the approved work plan, the borings were completed as groundwater monitoring wells MW4, MW5 and MW6 Soil and groundwater samples taken from MW4 contained detectable concentrations of TPHg and TPHd, but did not contain detectable concentrations of BTEX or • MTBE Soil and groundwater samples from MW5 and MW6 did not contain detectable concentrations of TPHg, TPHd, BTEX, or MTBE Field activities and analytical results were detailed in ATC's Summary Report of Additional Subsurface Investigation, dated September 7, 2000 SAMPLING ACTIVITIES On December 8, 2000, groundwater samples were collected by ATC personnel from monitoring wells MW I and MW3 through MW6 Well MW2 contained approximately one-tenth inches of free product and was subsequently not sampled The locations of the monitoring wells are shown on Figure 2 Prior to collection of groundwater samples, the depth to water, pH, electrical conductivity, and temperature were measured in the monitoring wells and recorded A minimum of three well casing volumes were purged from each well prior to sampling The wells were allowed to recover and samples were collected from each well using dedicated disposable bailers The groundwater samples collected from each well were submitted to State-certified Argon Laboratories, Inc (ELAP Cert No 2358) for chemical analysis of TPHg and TPHd utilizing EPA method 8015 modified, and BTEX and MTBE utilizing EPA Method 8020 Groundwater well purge and sample Iogs are contained in Attachment 1 GROUNDWATER FLOW DIRECTION . Water level measurements were collected from wells MW 1 through MW6 Less than one-tenth inches of free product was measured in well MW2 with an oil water interface probe Water levels ranged from 6 93 to 12 54 feet below the tops of the well casing elevations, representing w 1625001quart1yl4gr-2000 doc 2