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_ v CLEAVATE-R • G R O U P Envrrorementtl Servrctt of TPHg and BTEX were detected only in boring MW-5B The highest soil concentration of TPHg (1,000 mg/kg) was detected at 25 feet bgs in MW-5B This sample was also analyzed for TPH as Jet Fuel and found to contain 55 mg/kg Detectable concentrations of BTEX were present in soil samples collected from boring MW-5B at 25 feet and 35 feet bgs MTBE was not detected by EPA method 8260 in any of the soil samples analyzed Groundwater concentrations of TPHg and BTEX were detected in borings SB-9, MW-5B, MW-7 and MW-8 The highest groundwater concentration of TPHg (9,700 pg/L) was detected in MW-5B MTBE was not detected by EPA method 8260 in any of the groundwater samples analyzed Beginning in June, 2000 groundwater in all monitoring wells has been sampled on a calendar quarterly basis These sampling events took place on June 6, 2000, August 28, 2000, November 14, 2000, February 13, 2001, May 30, 2001, August 22, 2001, October 11, 2001, and February 14, 2002 Reports documenting these activities have been previously transmitted to the EHD by Clearwater OBJECTIVES In continuance of quarterly groundwater monitoring activities, the objectives of this current project were to gather groundwater samples from all monitoring wells at the site and to analyze • the groundwater samples for hydrocarbon contamination i GROUNDWATER MONITORING AND SAMPLING ACTIVITIES Groundwater monitoring and sampling activities were conducted on May 10, 2002 Groundwater elevation data were obtained from each of the monitoring wells A water level indicator was used for this purpose The water level indicator was thoroughly rinsed with distilled de-ionized water prior to placement in each well to prevent possible water quality influence from exterior sources Groundwater elevations were derived and are tied to previously determined well surface elevation data Before sampling, the wells were stabilized by purging of approximately three wetted casing volumes from each well All wells were checked for the presence of separate-phase hydrocarbons (SPH) prior to purging SPH were not observed to be present in any well Stabilization measurements of purge water temperature, conductivity and pH were made and recorded for each well Well stabilization data are enclosed in Attachment 2 Following purging, each well was allowed to recharge to at least 80% of its static water level prior to sampling Groundwater samples were obtained from each well using disposable polyethylene bailers Samples were labeled, documented on a chain-of-custody form, and placed on ice in a cooler for transport to the project laboratory All groundwater samples were analyzed by Entech Analytical Labs, a DHS certified laboratory, for concentrations of TPHg, BTEX and MTBE by EPA Method 8260B Additional information is contained in Clearwater's Groundwater Monitoring and Sampling Field Procedures included in this report as Attachment 1 ZB178C 3 June 3, 2002