Geohydrologic data for test well USW H-5, Yucca Mountain area, Nye County, Nevada

Abstract

This report presents data on drilling operations, lithology, borehole geophysics, water-level monitoring, core analysis, ground-water chemistry, pumping tests, and packer-injection tests for test well USW H-5. The well is one of a series of test wells drilled in and near the southwestern part of the Nevada Test Site, Nye County, Nevada, in cooperation with the U.S. Department of Energy. These test wells are part of the Nevada Nuclear Waste Storage Investigations to identify suitable sites for storage of high-level radioactive wastes. Test well USW H-5 was drilled to a total depth of 1,219 meters through volcanic rocks consisting mostly of ash-flow tuff. Depth to water in the well ranged between 703.8 and 707.2 meters below land surface, at an approximate altitude of 704 meters above sea level. Drawdown in the well exceeded 6 meters after test pumping more than 3,000 minutes at a rate of 10 liters per second. Borehole-flow surveys showed that about 90 percent of the water in the well is contributed by the zone between 707 and about 820 meters below land surface. Two composite water samples collected after well completion contained 206 and 220 milligrams per liter of dissolved solids. Sodium and bicarbonate were the predominant dissolved anion and cation. The concentration of dissolved silica was 48 milligrams per liter in both samples, which is a relatively large concentration for most natural waters.