Borehole data package for wells 299-W22-48, 299-W22-49, and 299-W22-50 at single-shell tank waste management Area S-SX

Three new Resource Conservation and Recovery Act (RCRA) groundwater monitoring wells were installed at the single-shell tank farm Waste Management Area (WMA) S-SX in October 1999 through February 2000 in fulfillment of Tri-Party Agreement (Ecology 1996) milestone M-24-41. The wells are 299-W22-48, 299-W22-49, and 299-W22-50. Well 299-W22-48 is located east of the southeast corner of 241-S tank farm and is a new downgradient well in the monitoring network. Well 299-W22-49 is located on the east side of the 241-SX tank farm, adjacent to well 299-W22-39, which it replaces in the monitoring network. Well 299-W22-50 is located at the southeast corner of the 241-SX tank farm and is a replacement for downgradient monitoring well 299-W22-46, which is going dry. The original assessment monitoring plan for WMA S-SX was issued in 1996 (Caggiano 1996). That plan was updated for the continued assessment at WMA S-SX in 1999 (Johnson and Chou 1999). The updated plan provides justification for the new wells. The new wells were constructed to the specifications and requirements described in Washington Administrative Code (WAC) 173-160 and WAC 173-303, the updated assessment plan for WMA S-SX (Johnson and Chou 1999), and the description of work for well drilling and construction. This document compiles information on the drilling and construction, well development, pump installation, and sediment and groundwater sampling applicable to the installation of wells 299-W22-48, 299-W22-49 and 299-W22-50. Appendix A contains the Well Summary Sheets (as-built diagrams), the Well Construction Summary Reports, and the geologist's logs. Appendix B contains results of laboratory analyses of the physical properties of sediment samples obtained during drilling. Appendix C contains borehole geophysical logs, and Appendix D contains the analytical results from groundwater samples obtained during well drilling and construction