Innovative Direct Push Technologies for Characterization of the 216-Z-9 Trench at DOE's Hanford Site -8235

ABSTRACT Because of the significant radiological and chemical hazards present at the 216-Z-9 Trench at the US Department of Energy Hanford Site, the only practical subsurface characterization methods are those that minimize or control airborne vapors and particles. This study evaluates and compares the performance of two Direct Push Technologies (Hydraulic Hammer Rig (HHR) and Cone Penetrometer Testing (CPT)) with traditional cable tool drilling in similar difficult geologic conditions. The performance was based on the depth of penetration, the ability to collect representative vadose zone soil samples, the penetration rate, and the relative cost. The HHR achieved deeper penetration depths and faster penetration rates than CPT techniques, while still maintaining the waste minimization benefits of direct push technologies. Although cable tool drilling achieved the deepest penetration, the safety and disposal concerns due to the soil cuttings that were generated made this drilling approach both slow and costly compared to the direct push techniques