Borehole Summary Report for C4997 Rotary Drilling, WTP Seismic Boreholes Project, CY 2006

The following Final Geologic Borehole Report briefly describes the drilling of a single borehole at the Waste Treatment Plant (WTP) on the Hanford, Washington, U.S. Department of Energy (DOE) reservation. The location of the WTP is illustrated in Figure 1-1. The borehole was designated as “C4997”, and was drilled to obtain seismic and lithologic data for the Pretreatment Facility and High-Level Waste Vitrification Plant in the WTP. Borehole C4997 was drilled and logged to a total depth of 1428 ft below ground surface (bgs) on October 8, 2006, and was located approximately 150 ft from a recently cored borehole, designated as “C4998”. Pacific Northwest National Laboratory (PNNL) determined the locations for C4997, C4998, and other boreholes at the WTP in cooperation with the U.S. Army Corps of Engineers (USACE) Review Panel, and the Defense Nuclear Facilities Safety Board (DNFSB). The total depth of Borehole C4997 was also determined by PNNL