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GEOPROBE OPERATION J CATEG • - GEO 4.12 - March 1998 • When the specified sample depth is reached, remove the drive cap and attach the pull cap. Pull the rod up approximately 1 foot. This will release the drive point and expose the open end of the PRT expendable point holder. Remove the pull cap to expose the open end of the rod. • Attach a clean, decontaminated PRT adapter with a rubber "O" ring to the end of the tubing and then insert the tubing and the PRT adapter down the inside of the rods until the PRT comes into contact with the PRT expendable point holder. • Cut the tubing at the surface so that there is plenty of tubing to connect to the vacuum source. Turn the tubing until the PRT adapter screws securely into the PRT point holder. • The soil-gas sample is now extracted from the soil and into a container using a vacuum. The container(glass bulb or Tedlar bag) is placed in- line between the vacuum pump and the tubing emerging from the drive rods. The sample is then collected using a vacuum. The vacuum is generated by the on-board vacuum volume pump. This pump will allow the operator to determine the volume of vapor extracted from the soil. • Once the soil-gas sample is collected, extract all drive rods and the PRT expendable point holder. The expendable point will remain in the ground. • Repeat these steps as necessary to collect additional subsurface soil-gas samples. 9. Abandonment of Probe Holes Before probe holes can be abandoned, regulations from the state in which the soil boring and well abandonment will be performed should be consulted. Each state may have specific regulations for soil boring and well abandonment,and these regulations can dictate the method and material that will be used to plug the probe holes. However, in most cases, the state will require that the probe holes be backfilled with some sort of bentonite clay(granular or a slurry). 14