Groundwater chemistry at the Nevada Test Site: Data and preliminary interpretations

Technical Report · Mon Mar 01 04:00:00 EST 1993

DOI:https://doi.org/10.2172/138650· OSTI ID:138650

Chapman, J B; Lyles, B F

The interpretation of chemical analyses of groundwater collected at and near the Nevada Test Site (NTS) has been vital in developing conceptual models of groundwater flow in the area. These conceptual models are tested using recent chemical data generated by the Desert Research Institute, as well as historic analyses from the US Geological Survey. A total of 81 wells are represented by analyses from 1957 to 1990, with generally excellent agreement between repeat samples from the same location. As identified by previous workers, three hydrochemical facies are represented by the samples: Ca-Mg-HCO{sub 3} water in carbonate rocks or alluvium derived from carbonates, Na-K-HCO{sub 3} water in volcanic rocks and alluvium derived from volcanic rocks, and a mixed fades found in many carbonate and alluvium water samples, and some volcanic waters. There is a general lack of lateral continuity in chemical characteristics along presumed flowpaths within each hydrologic unit (alluvium, carbonate, and volcanic). Though a lack of continuity between basins on the east side of the NTS was expected for water in alluvial and volcanic units due to the absence of interbasin flow, chemical differences observed within individual basins suggest a dominance of vertical over lateral flow. Groundwater in volcanic materials on the east side of Yucca and Frenchman Flats and on the west side of Pahute Mesa and Yucca Mountain has a nearly pure Na-K-HCO{sub 3} signature that reflects contact with primarily volcanic material. Groundwater in volcanic units in the middle of the NTS and on the east side of Pahute Mesa contains a higher proportion of Ca, Mg, Cl, and SO{sub 4} than the other volcanic waters and indicates the contribution of water from the upper carbonate aquifer and/or hydrothermally altered regions.

• Research Organization: Nevada Univ., Reno, NV (United States). Water Resources Center
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC08-90NV10845
• OSTI ID: 138650
• Report Number(s): DOE/NV/10845--16; ON: DE93017131
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
ACID CARBONATES
ALLUVIAL DEPOSITS
CALCIUM COMPOUNDS
CARBONATE ROCKS
CHEMICAL ANALYSIS
CHLORIDES
DATA ANALYSIS
EXPERIMENTAL DATA
FLUID FLOW
GROUND WATER
MAGNESIUM COMPOUNDS
NEVADA TEST SITE
SODIUM COMPOUNDS
SULFATES
VOLCANIC ROCKS
WATER CHEMISTRY
Yucca Mountain Project