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; F I ii i VAPOR SAMPLING On site sample analysis is performed using a Photovac 1OS50 PID chromatograph . The vapor samples are obtained by attaching a dedicated air tight 60 cc syringe to a sample port on the vapor recovery manifold, well side of the orifice plate, with air tight fitted polytubing. 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 cls and forceps are clamped onto the soft polytubing to create as aar 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 I cc suringe is then inserted into the 60 cc syringe via the soft tubing for obtaining the sample to be infected into the PID -M. Again the lcc syringe j is purged numerous times prior to falling it with the sample. All i but 0 .5 cc of the sample is effected 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 f instrument blank will indicate of residual peaks are being carried 4 onto the next analysis. The resulting chromatogram is then compared to a standard calibration run on the same chromatograph prior to the sample run. Whale 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 i pressure or vacuum that is being created at each well. COLLECTING LABORATORY SAMPLES 1 I INFLUENT SAMPLE s The influent sample is obtained from a sample port located after E the system vacuum pump before the carbo canisters. Sterile poly tubing is then used to attach a 1 liter tedlar bag, fatted with a special septum "valve" and tubing bib, to the sample port. Th& sample port is on the pressure side of the pump and therefore the bag will fill without need of a pump. Once the tedlar bag is filled, its' valve is closed and locked; the appropriate label is placed on the tedlar bag. • R604 vapor, 7731/92, p. 5