A complex pattern of active faults occurs in the southern Amargosa Desert, southern Nye, County, Nevada. These faults can be grouped into three main fault systems: (1) a NE-striking zone of faults that forms the southwest extension of the left-lateral Rock Valley fault zone, in the much larger Spotted Range-Mine Mountain structural zone, (2) a N-striking fault zone coinciding with a NNW-trending alignment of springs that is either a northward continuation of a fault along the west side of the Resting Spring Range or a N-striking branch fault of the Pahrump fault system, and (3) a NW-striking fault zone which is parallel to the Pahrump fault system, but is offset approximately 5 km with a left step in southern Ash Meadows. These three fault zones suggest extension is occurring in an E-W direction, which is compatible with the {approximately}N10W structural grain prevalent in the Death Valley extensional region to the west.

A total of 15 water-supply wells are currently being used at the Nevada Test Site (NTS). The purpose of this report is to bring together the information gleaned from investigations of these water-supply wells. This report should serve as a reference on well construction and completion, static water levels, lithologic and hydrologic characteristics of aquifers penetrated, and general water quality of water-supply wells at the NTS. Possible sources for contamination of the water-supply wells are also evaluated. Existing wells and underground nuclear tests conducted near (within 25 meters (m)) or below the water table within 2 kilometers (km) of a water-supply were located and their hydrogeologic relationship to the water-supply well determined.

In February 1983, the U.S. Department of Energy (DOE) identified the Yucca Mountain site in Nevada as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. The site is in the Great Basin, which is one of five distinct geohydrologic settings considered for the first repository. To determine their suitability, the Yucca Mountain site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for the Nuclear Waste Repositories. These evaluations were reported in draft environmental assessments (EAs), which were issued for public review and comment. After considering the comments received on the draft EAs, the DOE prepared the final EAs. On the basis of the evaluations reported in this EA, the DOE has found that the Yucca Mountain site is not disqualified under the guidelines. The DOE has also found that it is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is nominating the Yucca Mountain site …