Analysis of ER-12-3 FY 2005 Hydrologic Testing, Nevada Test Site, Nye County, Nevada, Rev. No.: 0

Abstract

This report documents the analysis of data collected for ER-12-3 during the fiscal year (FY) 2005 Rainier Mesa/Shoshone Mountain well development and hydraulic testing program (herein referred to as the ''testing program''). Well ER-12-3 was constructed and tested as a part of the Corrective Action Unit (CAU) 99, Rainier Mesa/Shoshone Mountain, Phase I drilling program during FY 2005. These activities were conducted on behalf of the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO) for the Underground Test Area (UGTA) Project. As shown on Figure 1-1, ER-12-3 is located in central Rainier Mesa, in Area 12 of the Nevada Test Site (NTS). Figure 1-2 shows the well location in relation to the tunnels under Rainier Mesa. The well was drilled to a total depth (TD) of 4,908 feet (ft) below ground surface (bgs) (surface elevation 7,390.8 ft above mean sea level [amsl]) in the area of several tunnels mined into Rainier Mesa that were used historically for nuclear testing (NNSA/NSO, 2006). The closest nuclear test to the well location was YUBA (U-12b.10), conducted in the U-12b Tunnel approximately 1,529 ft northeast of the well site. The YUBA test working point elevation was located at approximatelymore » 6,642 ft amsl. The YUBA test had an announced yield of 3.1 kilotons (kt) (SNJV, 2006b). The purpose of this hydrogeologic investigation well is to evaluate the deep Tertiary volcanic section below the tunnel level, which is above the regional water table, and to provide information on the section of the lower carbonate aquifer-thrust plate (LCA3) located below the Tertiary volcanic section (SNJV, 2005b). Details on the drilling and completion program are presented in the ''Completion Report for Well ER-12-3 Corrective Action Unit 99: Rainier Mesa - Shoshone Mountain'' (NNSA/NSO, 2006). Development and hydraulic testing of ER-12-3 took place between June 3 and July 22, 2005. The development objectives included removing residual drilling fluids and improving the hydraulic connection of the well within the lower carbonate aquifer (LCA). The hydraulic testing objectives focused on obtaining further hydrogeologic, geochemical, and radiochemical data for the site. Details on the data collected during the testing program are presented in the report ''Rainier Mesa Well ER-12-3 Data Report for Well Development and Hydraulic Testing'' (SNJV, 2006b). Participants in ER-12-3 testing activities were: Stoller-Navarro Joint Venture (SNJV), Bechtel Nevada (BN), Desert Research Institute (DRI), Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL), and the U.S. Geological Survey (USGS). Stoller-Navarro Joint Venture served as the lead contractor responsible for providing site supervision, development and testing services, and waste management services; BN provided construction and engineering support services; DRI provided well logging services and participated in groundwater sampling and laboratory analyses; LANL and LLNL participated in groundwater sampling and laboratory analyses; and the USGS performed laboratory analyses. Analyses of data from the ER-12-3 testing program presented in this document were performed by SNJV except as noted.« less