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1 <br /> baseline samples Each sample was collected using a disposable bailer after approximately <br /> 1-gallon of standing water had been removed Samples were collected in 40-nil VOA vials <br /> ' and transported in a chilled container, under chanr-of-custody, to MAI <br /> 3.6.3 Anal3lical Results of Air Samples <br /> ' The analytical results of the air samples are summarized in Table 5 Concentrations of TPH <br /> in the extracted vapors ranged from 35,000 yg/L to 56,000 ug/L Com erting these values <br /> t to parts per million volume (ppmv), concentrations ranged from 9,800 ppmv (at 6 hours) to <br /> 15,680 ppmv (at 12 hours) The laboratory report and chain-of-custody are included in <br /> Appendix F Equations for conversion are included in Appendix G <br /> ' 3.6.4 Analytical Results of Ground%%ater Samples <br /> ' Analytical results of groundwater samples collected on January 15, 1995 ale included in <br /> Table 3 In two of the air spargrng observation wells (ASO-1 and ASO-2), petroleum <br /> hydrocarbon concentrations increased srpnr6cantly from baseline samples collected on <br /> January 12 Samples from ASO-1 increased from 2 200 ppb to 73 000 ppb samples from <br /> ASO-2 increased from 5S 000 ppb to 73,000 ppb Ho\Ne\er, samples from ASO-3 indicated <br /> a decrease from 110 000 ppb to 52 000 ppb The laboratory report and chain-of-custody are <br /> ' included in Append» H <br /> 3 6 5 Vapor Extr action Feasibility <br /> Between 22 and 40 inches (HO) of vacuum was maintained at VE-1 throughout the pilot <br /> test The induced vacuum %\as measured rn VE-2, VE-3, VNV-1, ASO-1 ASO-2, NNW-3 and <br /> tNNW-4 The greatest \acuum rrleasured in the vapor extraction obser%atron \+ells was 2 4 <br /> inches, atwell VE-3 located approximately 15 feet northeast of VE-1 Ho"ever after three <br /> ' hours of the test, a %acuurn of 0 02 arches \Nas measured in \IW-3, more than 90 feet east <br /> of VE-1 Vacuum data is included in Table 4 <br /> Generally, a vacuum of 0 10 is ieclur3ed to successfully volatilize subsurface hydrocarbons <br /> ' The maximum vacuum measured at each well (at 2400 rpm) was plotted versus the distance <br /> of each well from the extraction well Figure 4 is a graph of distance vs vacuum for three <br /> ' observations wells (VE-2, VE-3 and VW-1) Drawing a "best fit" line through the three data <br /> points will deterrrirne the effective radius of influence at this site From Figure 4, the <br /> effective radius of influence at the site appears to be approximately 37 feet <br /> ' It appears that vapor eVractron, using an IC engine, would successfully remove a significant <br /> volume of petroleum h},drocarbons from impacted soil at the site Furthermore, it is likely <br /> ' that extraction on VE-2 (slant boring) will have a positive influence on impacted soil in the <br /> vicinity of MW-3 <br /> eira.v�N nj 13 vsrsc 94 0 1056 m <br />