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REG 603 UPDATE-7 3/24/92 • MW2/3 condensate trap product chromatogram and illustrates the active stripping, as the gasoline condensate proceeds towards the incenerator. Peaks 3, 6, 12 and 15 are absent in the drip sample and the Cao and greater hydrocarbons have increased in total percentage from 41% at the condensate trap to 45% prior to the filter. No chlorinated solvents were detected in these chromatogram comparisons; ie. 1, 2 ,-Dichloroethane (DCE) - retention time 2. 079 minutes, Trichloroethylene (TCE) - retention time 3 .023 minutes and Tetrachloroethylene (PCE) - retention time 3 . 75 minutes. As of March 18 , 1992, a total of 2634. 5 gallons of gasoline range hydrocarbons have been removed from the soil and ground water beneath this site with the condensate traps recovery, combined with previously removed floating product (40. 25 gallons) and vapor extraction-destruction of hydrocarbons ( 16156 pounds/6 . 25 - 2584. 96 gallons) 4. 0 DISCUSSION AND CONCLUSIONS As stated in earlier reports, the soil is contaminated with . gasoline range hydrocarbons beneath the tank field (MW10 ) and along the capillary fringe of the ground water, MW1, MW2 , MW3 and MW10 . Ground water beneath the site contains the dissolved constituents of gasoline range hydrocarbons and has spread out from beneath the site to the north MW-6 , to the south MW-7 to the west MW-9 and to the east MW-8 . Vapor extraction commenced on October 17, 1991 and up until March 18 , 1992 has operated for 2611 hours out of a possible 3674 for a 71% run time, destroying 16, 156 pounds of gasoline range hydrocarbons. Since the last status report, February 3 , 1992, a total of 4884 pounds of gasoline range hydrocarbons have been removed/destroyed. DCE, TCE and PCE screening indicates that these compounds are not present in the vapor stream at this site. Ground water elevation measurements show the ground water is being mounded at the lower K value wells MW3 and MW10, while the overall flow direction is to the northeast and southeast. Ground water sample results obtained on December 17, 1991, approximately 1473 hours after commencement of vapor extraction compared to the ground water sample results obtained on March 10, 1992, 3480 hours after commencement of vapor extraction, show a decline in the extent of the the dissolved constituents -in all of the monitoring wells with the exception of MW1, MW3 and MW10 which have floating product, see Table 1 and Figures 5A and 5B . It is felt that once the air dilute has been completely closed and PAGE 11