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REG 603 UPDATE-9 9/14/92 • The sample port is then opened and the syringe is purged by pulling and pushing the syringe plunger several times filling and depleting the syringe of that particular wells vapor stream. Then the syringe is filled, the sample valve closed and forceps are used to clamp onto the soft polytubing to create an air tight seal for the syringe before removing the syringe from the sample port. Once the 60 cc syringe is removed with the forceps clamped polytubing attached, the plunger is pushed into the syringe to create pressure within the syringe and released to allow the vapors that have been captured to reach equilibrium. A small dedicated needle attached to a dedicated 1 cc suringe is then inserted into the 60 cc syringe via the soft tubing for obtaining the sample to be injected into the PID-GC. Again the lcc syringe is purged numerous times prior to filling it with the sample. All but 0 . 5 cc of the sample is ejected into the air prior to injecting the remaining 0 .5 cc syringe sample into the GC--PID (the calibrant injection is 0 . 5 cc ) . Once the chromatogram has been recorded an instrument blank is run prior to the next sample. The instrument blank will indicate if residual peaks are being carried onto the next analysis . While the GC-PID analysis is running for a particular sample ( 15 minutes per sample run) , vacuum influent readings are obtained from the wells by attaching a manometer calibrated in mm water to } ! sample ports at the well heads . These readings show the mm water �€ pressure or vacuum that is being created at each well . ii Occasionally the lOS50 PID-GC is not available for field determination of the influent and effluent streams . Tedlar bag it samples are then obtained and brought back to the WEGE portable laboratory for analysis using a FID-GC, see Appendix C - Field Notes . j VAPOR RECOVERY OPERATIONS AND RESULTS As has been stated in earlier reports , soil contamination exists from beneath the tank excavation to the top of the ground water . Overexcavation during the intial tank removal , removed contaminated soil to the 25 foot depth. Prior to replacement of 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 i compound with SCH 40 2 inch and 4 inch PVC pipe . These pipes along with monitor wells MW1 , MW2 , MW3 and MW10 are being used for vapor extraction - soil and ground water remediation. # On October 10 , 1991 the vapor extraction system operated for 6 . hours , to check the auto shut downs and percent destruction of the i PAGE 7 i