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i CLEARWATER G R O C1 •P I N C ' 3.0 FIELD ACTIVITIES All field work was conducted according to Clearwater Field Proceedures (previously Isubmitted) which are consistent with both local and state guidelines Prior to sampling, each monitoring well was gauged to the nearest hundredth of a foot The wells were then purged of at least three well casing volumes until purging parameters stabilized or until the well went dry Monitoring well purge/sample data sheets are included as Appendix B ' Groundwater samples were collected from all five monitoring wells Each groundwater sample was collected with a dedicated polyethylene bailer and was transferred to sample containers appropriate for the required analyses Sample containers were labeled and placed in a cooler A chain-of-custody was prepared and accompanied the samples to the laboratory Groundwater sample analysis was performed by PACE, Inc , DHS-certified laboratory located in Novato, California All groundwater samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg) by EPA Method 8015 (CA LUFT modified), and for benzene, toluene, ethylbenzene and total xylenes (BTEX) by EPA Method 8020 (CA LUFT modified) 4.0 RESULTS 4.1 Water Level Monitoring Data The depth to groundwater in the monitoring wells ranged from 23 83 to 24.46 feet below ground surface (bgs) on March 13, 1995 The depth to groundwater was ' measured from the survey mark on top of each well casing Groundwater elevations are presented on Table 1 Groundwater elevation contours are presented on Figure 3 The local groundwater flow direction was calculated to be towards the ' east (towards the northeast in the southern half of the site) at an approximate gradient of 0 65% (0 0065 feet/foot) The groundwater flow direction and gradient is consistent with results obtained during the previous monitoring events I4.2 Ground Water Analytical Results TPHg and benzene were detected in groundwater samples collected from all wells except MW-5 None of the analytes were detected in concentrations exceeding method detection limits in groundwater sample collected from MW-5 The detected concentrations of benzene ranged from 2 0 ppb in the sample collected from MW-1 to 170 ppb in the sample collected from MW-3. A summary of analytical results is presented on Table 1 Hydrocarbon concentrations are shown on Figure 4 A copy of the laboratory reports and chain-of-custody form is attached as Appendix C. D-103 QMR 2 4/21/95