Completion report for well ER-30-1
as part of a hydrogeologic investigation program for the Yucca Flat Corrective Action Unit. The overall purpose of the well was to gather subsurface data to better characterize the hydrogeology in the northwestern portion of Yucca Flat. The well was drilled to total measured depth of 2,097.9 meters. The 131.1-centimeter-diameter borehole was left open (i.e., uncased) below the base of the intermediate casing at 901.6 meters. A piezometer string was installed outside the surface casing to a
... ce casing to a depth of 176.4 meters to monitor a zone of perched water. Data gathered during and shortly after hole construction include composite drill cuttings samples collected every 3 meters, sidewall core samples from 7 depths, various geophysical logs, and water level measurements. These data indicate that the well penetrated, in descending order, 137.5 meters of Quaternary and Tertiary alluvium, 48.8 meters of Tertiary volcanic rocks, 289.6 meters of Mississippian Chainman Shale, and 1,622.5 meters of Mississippian and Upper Devonian Eleana Formation consisting of shale, argillite, sandstone, quartzite, and limestone. Forty-seven days after the well was drilled the water level inside the main hole was tagged at the depth of 65.43 meters, and the water level inside the piezometer string was tagged at 127.14 meters. vi This page intentionally left blank.