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L F R a9 14 ARCADIS company <br /> and submitted with this Work Plan under separate cover. A summary of that investigation is <br /> provided below. <br /> Scope of Work. A subsurface utility subcontractor was retained to locate and map the location of <br /> the sanitary sewer line that services the dry-cleaning facility. Soil and groundwater samples were <br /> collected from each of three borings advanced along the sanitary sewer line (SB-1 through SB-3, <br /> Figure 2) and submitted to an analytical laboratory for chemical analysis. <br /> Results. PCE was not detected in any of the 10 soil samples collected from these borings, and only <br /> low concentrations of PCE (1.4 µg/L to 2.3 µg/L) were detected in grab groundwater samples <br /> collected from the borings. These low concentrations of PCE are consistent with the occurrence of <br /> low concentrations of PCE historically encountered in groundwater in the area. The lack of <br /> detection of PCE in any of the 10 soil samples strongly suggests that the C&S dry-cleaning facility <br /> is not the source for the low concentrations of PCE that have been detected in groundwater in the <br /> area. <br /> Proposed Soil-Vapor Extraction Pilot Test <br /> Objectives Overview <br /> The overall objective of this phase of work is to assess whether SVE is a potential economically <br /> and technically feasible technology to reduce the concentrations of PCE in soil gas beneath the <br /> facility. If the SVE pilot test is deemed effective, LFR proposes to identify SVE well spacing, <br /> carbon treatment, and blower specification requirements for the design of a full-scale soil-vapor <br /> extraction and treatment system (SVETS). <br /> Specific Objectives and Approach <br /> Specific objectives for the proposed pilot test include: <br /> • Determining if a reasonable vacuum can be established in the unsaturated soil at the Site. <br /> • Collecting air flow and pressure data adequate to identify extraction well spacing requirements <br /> for the design of a SVETS to remediate unsaturated-zone soil at the Site, if applicable. The <br /> primary factors for well spacing design include the following: <br /> • extraction flow rates achieved in response to applied vacuum <br /> • soil permeability <br /> • pressure distribution around wells at different extraction flow rates (generally referred <br /> to as "radius of influence" or "area of influence") <br /> .p-CS-SVE-May09-09366.dm:deh 4 <br />