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D.J. Burkhardt

Publications and source records attributed to D.J. Burkhardt.

4 recordsLinked to original sources
USGS1993

Revised potentiometric-surface map, Yucca Mountain and vicinity, Nevada

The revised potentiometric-surface map presented in this report updates earlier maps of the Yucca Mountain area using mainly 1988 average water levels. Because of refinements in the corrections to the water-level measurements, these water levels have increased accuracy and precision over older values. The small-gradient area to the southeast of Yucca Mountain is contoured with a 0.25-meter interval and ranges in water-level altitude from 728.5 to 731.0 meters. Other areas with different water levels, to the north and west of Yucca Mountain, are illustrated with shaded patterns. The potentiometric surface can be divided into three regions: 1) A small-gradient area to the southeast of Yucca Mountain, which may be explained by flow through high-transmissivity rocks or low ground-water flux through the area; 2) A moderate-gradient area, on the western side of Yucca Mountain, where the water-level altitude ranges from 775 to 780 meters, and appears to be impeded by the Solitario Canyon Fault and a splay of that fault; and 3) A large-gradient area, to the north-northeast of Yucca Mountain, where water level altitude ranges from 738 to 1,035 meters, possibly as a result of a semi-perched groundwater system. Water levels from wells at Yucca Mountain were examined for yearly trends (1986-89) using linear least-squares regression. Data from five wells exhibited trends which were statistically significant, but some of those may be a result of slow equilibration of the water level from drilling in less permeable rocks. Adjustments for temperature and density changes in the deep wells with long fluid columns were attempted, but some of the adjusted data did not fit the surrounding data and, thus, were not used.

Water-Resources Investigations Report↗
USGS1993

Summary of revised potentiometric-surface map for Yucca Mountain and vicinity, Nevada

The revised map for the potentiometric surface of the uppermost saturated zone in Tertiary volcanic rocks at Yucca Mountain, Nevada, is based mainly on 1988 water levels. Refinement of the water-level corrections has increased understanding of the area immediately east-southeast and hydrologically downgradient of Yucca Mountain. This small-gradient area is a nearly horizontal surface which corresponds to the likely direction of ground-water flow from Yucca Mountain - east-southeast. To the west of Yucca Mountain, water levels are approximately 45 m higher than those in the small-gradient area, and to the east of the northern part of Yucca Mountain water levels are approximately 300 m higher than those in the small-gradient area. Water levels are higher to the west of Yucca Mountain apparently because of a barrier to ground-water flow formed by the Solitario Canyon fault and a splay of the fault, and water levels are higher to the north apparently because of a semi-perched ground-water system.

Conference Paper↗