Water levels in the Yucca Mountain area, Nevada, 1997-98

Abstract

Water levels were monitored in 24 wells in the Yucca Mountain area, Nevada, during 1997 and 26 wells during 1998. These wells, which represented 31 depth intervals during 1997 and 33 depth intervals during 1998, were monitored periodically. All wells monitor water levels in volcanic rocks of Tertiary age except one that monitors water levels in carbonate rocks of Paleozoic age. Mean water-level altitudes in the Tertiary volcanic rocks ranged from 727.87 to 1,034.57 meters above sea level during 1997 and from 727.86 to 1,034.76 meters above sea level during 1998. The mean water-level altitude in the well monitoring the Paleozoic carbonate rocks was 752.71 and 752.87 meters above sea level during 1997 and 1998, respectively. During 1997-98, water levels in the Yucca Mountain area could have been affected by long-term pumping at the C-hole complex that began on May 8, 1996, and continued through November 12, 1997. Other groundwater pumpage in the Yucca Mountain area included annual pumpage from water-supply wells UE-25 J-12 and UE-25 J-13.