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, CAMBRIA <br /> SOIL VAPOR EXTRACTION TEST RESULTS <br /> Initial vapor concentrations were moderate on the first day of testing, indicating the presence of <br /> source material in the target area Initial field measurements of vapor concentrations, using the <br /> Horiba hydrocarbon analyzer, approximated hydrocarbon concentrations at 400 ppmv in well <br /> VE-1 and 1,000 ppmv in well VE-2 With VE-1 and VE-2 coupled for the long-term test, the <br /> analyzer approximated hydrocarbon concentrations at 550 ppmv, which is consistent with the <br /> laboratory results <br /> The permeability of the native soil yielded a fair extraction rate and radius of influence To <br /> determine the effective radius of influence, the applied vacuum was compared to the vacuum <br /> observed in the nearby wells The theoretical radius of influence was estimated according to the <br /> steady-state radial distribution equation in A Practical Approach to the Design, Operation, and <br /> Monitoring of In Situ Soil Venting Systems (P C Johnson, C C Stanley, M W Kemblowski,D L <br /> Byers, and J D Colthart, Groundwater Monitoring and Review, Spring 1990) As shown in <br /> Table 3, the theoretical radius of vacuum influence extends to almost 16 feet in the 15 to 30 fbg- <br /> screened zone (VE-1 and VE-2) The theoretical radius of vacuum influence extends to 7 2 to <br /> 10 7 feet in the 50 to 70 fbg-screened zone (MW-5) Figure 3 illustrates the extent of vapor <br /> extraction During the SVE test approximately 13 6 pounds of TPHg and 5 0 pounds of MTBE <br /> were removed <br /> CONFIRMATION SOIL BORING <br /> An additional soil boring (VE-3) was drilled at the location shown on Figure 2 This well is <br /> placed adjacent to well MW-5,to confirm that SVE removed MTBE from the soil <br /> Personnel: Cambria geologist Scott Lewis directed the field activities, <br /> working under the supervision of California Registered <br /> Geologist Joe Neely <br /> Permits Well permit No 0024476 was obtained from SJCPHSIEHD <br /> (Appendix A) Equilon obtained an access agreement with the <br /> subject site property owners <br /> Drilling Company Gregg Drilling & Testing, Inc of Martinez, California <br /> (C57 License No 485165) <br /> Drilling Date• December 19, 2001 <br /> 1346 7 <br />