Well Installation Report for Monitoring Wells TCM4, TCM5, and TCM8 and Pilot Hole TGSC-2A

The shallow groundwater and sediments beneath the TNX Area are contaminated with both dissolved and residual chlorinated volatile organic compounds (CVOCs) such as trichloroethylene (TCE), carbon tetrachloride and perchloroethylene (PCE)..The Savannah River Technology Center (SRTC) is studying a new technology for remediating CVOCs known as GeoSiphon. The GeoSiphon Cell is a large diameter well uses granular cast iron for filter pack material and is operated by inducing a siphon to draw contaminated groundwater through the iron filter pack. As groundwater flows through the granular cast iron CVOCs are reduced to ethane, ethene, methane, and chloride ions. Previous laboratory and field studies (ETI, 1996, and Phifer et. al., 1997) conducted by SRTC have shown that granular cast iron is capable of remediating contaminated at TNX. SRTC will be conducting a Dual Cell test of the GeoSiphon technology in 1999 to study the hydraulic interaction of multiple cells operating simultaneously.T his report documents the installation of 3 monitoring wells and 1 pilot hole that were installed to support the Dual phase test. The three monitoring wells will be used to study the hydraulic interaction between the 2 GeoSiphon cells. Continuous core was collected from the proposed location for the second GeoSiphon Cell TGSC-2. Depth discrete samples collected from the core were analyzed for CVOCs