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R603 UPDATE-14 3/25/93 at the well heads These readings show the mm water pressure or vacuum that is being created at each well, see Appendix C - Field Notes . VAPOR RECOVERY OPERATIONS AND RESULTS As stated in earlier reports, soil contamination exists from beneath the tank excavation to the top of the ground water Overexcavation during the initial tank removal , removed contaminated soil to the 25 foot depth. Before replacing the new double contained fiberglass tanks and dispensing system, 4 inch and 6 inch SCH 40 PVC 0 . 02 inch slotted pipes were placed vertically at the north corner and west corner of the excavation respectively and manifolded via underground to the treatment compound with SCH 40 2 inch and 4 inch PVC pipe These pipes along with monitor wells MW1, MW2, MW3 and MW10 are used for vapor extraction for soil and ground water remediation. On October 10 , 1991 the vapor extraction system operated six hours, to check the auto shutdowns and percent destruction of the REMOX unit, using monitor wells MW1, MW10, and the excavation wells The system was restarted on October 17, 1991 and initial inspection and operation of the system occurred The unit operated until November 5, 1991, when it was shut down to replace a worn bearing The system was restarted on November 20, 1991 and operated until December 24, 1991 On this date someone turned off the main breaker that services the treatment compound This breaker box has since been locked. The unit was restarted on January 3 , 1992 and operated until July 20 , 1992 , with occasional auto shutdowns due to high temperature (15500F) in the pre-oxidation chamber. On July 20 , 1992, the heat exchanger malfunctioned and the incinerator shut down due to low temperature The unit remained off until it was replaced on August 18 , 1992 with a new unit . Presently (February 18, 1993) the REMOX units have operated for a total of 7067 hours out of a total of 11058 5 hours (64%) . The new replacement unit has operated 3065 hours out of 4411 5 hours (69 , 5%) , removing and destroying 61242 pounds of gasoline range hydrocarbons and an estimated 43462 pounds of oxidized gasoline range hydrocarbons as CO2 (Average 200 cfm flow rate X average CO2% (1 . 25) x 7067 hours operated x 60 min/hour x pound CO2 conversion 0 . 00041 lb/cf/%) for a total. of 104704 pounds of gasoline range hydrocarbons removed from the subsurface, see ma lloa 7 and -A and Annendix A-Air Monitoring Report . 4. 0 CONDENSATE REMOVAL AND WELL PURGING BY LTT Condensation from vapor extraction is collected in moisture drop out tanks constructed of 12" PVC pipe, before the manifold, to prevent moisture build up on the vacuum pump filter All fluids removed from the condensation traps are placed in the 1000 gallon "ConVault" As of December 1, 1992 a total of 22 . 5 gallons of product and 162 gallons of water have been removed from the PAGE 7