Completion Report for Wells ER-20-8 and ER-20-8#2 Corrective Action Units 101 and 102: Central and Western Pahute Mesa

Abstract

, as part of the Pahute Mesa Phase II drilling program. The primary purpose of these wells was to provide detailed hydrogeologic information in the Tertiary volcanic section that will help address uncertainties within the Pahute Mesa-Oasis Valley hydrostratigraphic framework model. They may also be used as long-term monitoring wells. The original plan was to drill one well, with completion zones in each of three aquifers originally predicted at this location. However, a fourth aquifer located below the first aquifer was unexpectedly encountered and contained low levels of tritium. The upper two aquifers were isolated behind casing before drilling into the lower aquifers in Well ER-20-8.Well ER-20-8#2 was then drilled on the same pad and did not penetrate the lower two aquifers; completions were installed in the upper two aquifers.