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F }J t.r 14 toluene,ethlybenzene and xylenes(STEX)and total petroleum hydrocarbons-as-gasoline(TPH-G). GTEL is certified by the State of California to perform these analyses. Air samples were collected from MW-3,MW-5,and fviW.0 after approximately one hour of testing. K Vapors were then extracted from MW-2 for 6 days at 130 cim to determine a hydrocarbon concentration km 29 dissipation curve for extracted vapors. 3.3.2 Soil Vapor Extraction Pilot Test Results The results of vacuum measurements taken during the soil vapor extraction pilot test are recorded in Appendix L These vacuum measurements allow definition of the subsurface volume of soil that is was defined as affected by the applied vacuum,stated as a radius of influence. The radius of influence the distance at which measured vacuum would be equal to 0.1 inchos of water. The radius of influence was graphically determined for each measured condition from a tog-normal plot of vacuum versus distance (Appendix 1). The results are summarized in Table 1. _,. TABLE 1 SOIL VAPOR EY•TRACTION PILOT TEST RESULTS RADIUS OF INFLUENCE MANTECA BEAN FACILITY, MANTECA,CALIFORNiA MAY 8-14,1990 RADIUS OF INFLUENCE (FEET) EXTRACTION FLOW RATE POINT (CFPA) 130 90 MW-2 75 I MW-2 65 55 MW-2 37 80 MW-3 130 90 MW-5 130 130 90 MW-6 Three different flow rates were tested using MW-21n order to Cetermine the relationship between the flow rate and the radius of influence. As expected,the radius of influence decreased as the flow rate was reduced. The graph of flow rate versus radius of influence is in Appendix I,and is used to select the optimum blower size for the total system. Table 2 summarizes laboratory analyses of hydrocarbon concentrations in vapor collected during the pilot test. The five Samples taken from MW-2 were part of the six day test. -� GR0IJNt)%vxrFR TECHNOLOGY.INC. --- eb