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_ <br /> - <br /> i <br /> 1 <br /> w.• <br /> 3.1 Extractign Well and Manometer Point Installati_an <br /> Location acid configuration of the extraction well is based primarily on the assessed <br /> distribution of petroleum hydrocarbons in the subsurface. The source of subsurface <br /> data is Western Geologic Resources, Inc. (WGR) "Subsurface Investigation"reports <br /> dated November 1989 and August 1990. <br /> 3.1.1 Location and Depth of Extraction Wel!_and Manometer Points <br /> One extraction well pair (VEW-1) consisting of one shallow and one deep <br /> well casing, was installed at the west end of the former tank location. Two <br /> manometer pairs(MP-1 and MP-2)were installed approximately 15 feet east <br /> of VEW-1 and 25 feet west of VEW-1, respectively. Figure 2 shows the <br /> approximate locations of the extraction well and manometer points. MP-3 <br /> was not installed as originally planned. The presence of overhead and <br /> subsurface obstructions and overhead high voltage power lines prevented safe <br /> accessibility by the drill rig in the vicinity of MP-3's proposed location. <br /> The two manometer pairs(MP-1 and MP-2)were installed to collect vacuum- <br /> pressure data from around the extraction well. Measurements recorded at <br /> each manometer during vapor extraction were used to evaluate the expected <br /> radius-of-influence for the selected blower. An inclined U-tube manometer <br /> filled with water was used to measure vacuum pressures at each manometer <br /> point. <br /> 3.1.2 Extraction Well and Manometer Point Construction <br /> Bore holes for VEW-1 Shallow and Deep, MP-1, and MP-2 were drilled to <br /> depths of 34 and 66 feet, , respectively, using a Mobile <br /> Drill equipped with an eight inch Hollow Stem Auger. No groundwater was <br /> encountered in the bore holes. <br /> The VEW-1 well pair is constructed of two-inch diameter,open-ended,blank <br /> PVC casing set in a#3 sand backfill to depths of 30 and 63 feet, respectively. <br /> MP-1 and MP-2 pairs are constructed of 3/4 inch PVC casing set in#3 sand <br /> backfill to depths of 33 and 63 feet, respectively. The construction details for <br /> the extraction well and manometer points are shown on the Well Logs(Plates <br /> 2,3 & 4) Appendix A. <br /> 3.2 Soil Sampling& B@Iseline Chemical An 1 s s <br /> -- Chemical analyses were used to confirm the site assessment data,obiained byI R <br /> in 1989-90, and to establish a baseline for soil contaminant concentrations which <br /> would be used to evaluate the effectiveness of the forthcoming in-situ vapor <br /> - extraction remediation project.. . . <br /> 2 REMEDIATION <br /> SERVICES, INC. <br /> l <br />