“…The depth to groundwater in wells at the NTS varies from about 210 m (690 ft) below the land surface under the Frenchman Flat playa in the southeastern NTS to more than 610 m (2,000 ft) below the land surface in the northwestern NTS beneath Pahute Mesa Robie et al, 1995;IT, 1996b;O'Hagan and Laczniak, 1996;Bright et al, 2001;Locke and La Camera, 2003;Fenelon, 2005;. Perched groundwater (isolated lenses of water lying above the regional groundwater level) occurs locally throughout the NTS, mainly within the volcanic rocks.…”