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I �ei 05 April 1996 AGE -NC Project No 95-0142 _ Page 2of5 ' site to investigate the lateral and vertical extent of hydrocarbon -impacted soil and ground water Soil and vapor samples collected during the investigation have shown that hydrocarbon -impacted soil in the upper vadose zone at the site is limited to the immediate vicinity (30 -foot radius) of the former ' UST excavation (TK 1-90) Hydrocarbon -impacted ground water at the site has been detected in wells MW -1, MW -2 and MW -3 . ' In October 1995, a soil vapor extraction (SVE) pilot test was performed by AGE to evaluate remedial options for the site Based upon the results of the pilot test, installation of a soil vapor extraction/m- ' situ air spargnng (SVE/IAS) system was recommended in a Corrective Action Plan (CAP) prepared by AGE Details of the site assessment and the proposed SVE/IAS system are included in the CAP, prepared and submitted by AGE in December 1995 3.0. PROCEDURES 3 1 MONITORING WELL PURGE PROCEDURES The scope of work included the monitoring and sampling of two ground water monitoring wells and one SVE well Well VE -3 was sampled in lieu of MW -2 at the request of Mr Harlin Knoll of the PHS-EHD On 08 March 1996, a Solinst water level meter was used to measure the depth to ground water in wells MW -1 through MW -4 and VE -3 The relative ground water elevation in each well and hydraulic gradient were determine from these data points (Table 1) 'After depth to water measurements, approximately 7 to 45 gallons of water (a minimum of 3 well volumes) were removed from MW -3, MW -4 and VE -3 using a two-stage submersible pump Temperature, pH, and conductivity were measured at regular intervals using an ICM water analyzer Monitoring well stabnlnzatnon'data and field data sheets are included in Appendix A Purged water was stored on-site in 55 -gallon drums 3 2 COLLECTION OF GROUND WATER SAMPLES ' Water samples were collected from each purged well using new, clean disposable plastic bailers Immediately upon retrieval, the samples were transferred into 40-m1 VOA vials containing hydrochloric acid as a preservative, and were transported to McCampbell Analytical, Inc (MAI) in ' Pacheco, California All samples were analyzed for total petroleum hydrocarbons quantified as gasoline (TPH-g), volatile aromatics (benzene, toluene, -ethyl benzene and xylenes BTE&X) and methyl -tent -butyl ether (MTBE) in, accordance with EPA methods 8015/5030, 8020/602 and 8020/602, respectively , r i --