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Mr MlchaelIn£urna July 21, 2006 Page 5 AS/SVE Combined The total flow rate for the SVE portion of the combined AS/SVE test was between 98 3 and 163 1 scfm The total VOC values from VEW-1 were initially measured at 5,420 ppm then decreased to 930 ppm after 12 days of the combined AS/SVE operation as shown in Table 4 Figure 6 shows the field measured total VOC concentrations over titre from VEW-1 during the SVE and combined AS/SVE pilot test The figure shows a sharp decrease during the SVE component of the test and a steady decline over time during the AS/SVE y component of the test Analytical Data Laboratory analytical results for groundwater sampling during the first quarter of 2006 (prior to pilot test startup) and the second quarter 2006 (after shutdown of the pilot test) are summarized in Table 5 Concentrations of M"1 BE in the site monitoring wells during the first and second quarter 2006 monitoring events are illustrated on Figure 7 The groundwater analytical results indicate a large decrease in the MTBE concentration in MW-1 The concentration in MW-1 during the first quarter 2006 was 43,000 micrograms per liter (µg/L) The concentration increased to 64,000 pg/L prior to startup of the SVE system However, following the 13 days of operation of the pilot test, the concentration in MW-1 had decreased to 13,000 µg/L, a decrease of approximately 80 percent The concentration of MTBE decreased further to 7,000 µg/L when sampled during the second quarter 2006 monitoring event Figure 8 shows the historical concentration of MTBE in MW-1 The MTBE results following shutdown of the pilot test and second quarter 2006 are lower than any detections since third quarter 2001 Copies of the laboratory analytical reports for groundwater samples collected during first quarter 2006, during the pilot tests, and during second quarter 2006 are presented in Attachment B Laboratory analytical results for air samples collected during the test are summarized in Table 6 These results indicate MTBE had the highest concentrations of the detected compounds,ranging from 1,500,000 parts per billion by volume (ppbv) at SVE startup to 260,000 ppbv at AS/SVE shutdown, a decrease of approximately 80 percent Other common gasoline compounds reported included benzene, toluene, ethylbenzene,m,p-xylene, o-xylene,hexane, cycloheaxane,2,2,4-trimethylpentane, heptane, cumene, propylbenzene, 4-ethyltoluene, 1,3,5-trimethylbenzene, and 1,2,4-tnmethylbenzene Reported values for benzene ranged from 400,000 ppbv to 14,000 ppbv and toluene ranged from 1,200,000 ppbv to 240,000 ppbv Copies of the laboratory analytical reports for vapor samples are presented in Attachment C Mass extraction rates were calculated based on the analytical laboratory reported M"1BE, benzene,and toluene concentrations and soil vapor extraction flow rates ]'\28000\128251-Mf Trucking qVF\Documents\SVF Report amw doe