Keith J Halford (Former Employee)
Science and Products
Groundwater characterization and effects of pumping in the Death Valley regional groundwater flow system, Nevada and California, with special reference to Devils Hole
Groundwater flow and development were characterized in four groundwater basins of the Death Valley regional flow system in Nevada and California with calibrated, groundwater-flow models. Natural groundwater discharges in the Furnace Creek, Lower Amargosa, and Saratoga Spring areas were defined and distributed consistently with a revised...
Halford, Keith J.; Jackson, Tracie R.
Estimation of groundwater flow through Yucca Flat based on a multiple-well aquifer test at well ER-6–1–2 main, Nevada National Security Site, southern Nevada
The rate of groundwater flow past underground nuclear testing areas in Yucca Flat at the Nevada National Security Site, southern Nevada, was estimated using results from the ER-6-1-2 main multiple-well aquifer test (MWAT), done during February 5–July 23, 2004. Drawdowns in 13 observation wells were evaluated from pumping in well ER-6-1-2 main and...
Jackson, Tracie R.; Halford, Keith J.
Evaluation of groundwater-flow models for estimating drawdown from proposed groundwater development in Tule Desert, Nevada
At the request of the Bureau of Land Management (BLM), the U.S. Geological Survey (USGS) is releasing with this open-file report (OFR) a previously unpublished review and comparison of two numerical models for Tule Desert, Nevada. The original review was performed in spring 2013, and only minor editorial revisions were made in the current (2019)...
Halford, Keith J.
Documentation of single-well aquifer tests and integrated borehole analyses, Pahute Mesa and Vicinity, Nevada
Single-well aquifer testing has been carried out at Pahute Mesa in southern Nevada since 1962. These tests include single-well pumping and slug tests to estimate geologic formation hydraulic properties. Initially, aquifer tests focused on identifying low-permeability rocks suitable for testing large-yield nuclear devices, whereas later hydrologic...
Frus, Rebecca J.; Halford, Keith J.
Evaluating micrometeorological estimates of groundwater discharge from Great Basin desert playas
Groundwater availability studies in the arid southwestern United States traditionally have assumed that groundwater discharge by evapotranspiration (ETg) from desert playas is a significant component of the groundwater budget. However, desert playa ETg rates are poorly constrained by Bowen Ratio energy budget (BREB) and eddy-covariance (EC)...
Jackson, Tracie; Halford, Keith J.; Gardner, Philip M.; Garcia, Amanda
A process to estimate net infiltration using a site-scale water-budget approach, Rainier Mesa, Nevada National Security Site, Nevada, 2002–05
This report documents a process used to estimate net infiltration from precipitation, evapotranspiration (ET), and soil data acquired at two sites on Rainier Mesa. Rainier Mesa is a groundwater recharge area within the Nevada National Security Site where recharged water flows through bedrock fractures to a deep (450 meters) water table. The U.S....
Smith, David W.; Moreo, Michael T.; Garcia, C. Amanda; Halford, Keith J.; Fenelon, Joseph M. Scenario Evaluator for Electrical Resistivity survey pre-modeling tool
Geophysical tools have much to offer users in environmental, water resource, and geotechnical fields; however, techniques such as electrical resistivity imaging (ERI) are often oversold and/or overinterpreted due to a lack of understanding of the limitations of the techniques, such as the appropriate depth intervals or resolution of the methods....
Terry, Neil; Day-Lewis, Frederick D.; Robinson, Judith L.; Slater, Lee D.; Halford, Keith J.; Binley, Andrew; Lane, John W.; Werkema, Dale D.
Hydraulic characterization of volcanic rocks in Pahute Mesa using an integrated analysis of 16 multiple-well aquifer tests, Nevada National Security Site, 2009–14
An improved understanding of groundwater flow and radionuclide migration downgradient from underground nuclear-testing areas at Pahute Mesa, Nevada National Security Site, requires accurate subsurface hydraulic characterization. To improve conceptual models of flow and transport in the complex hydrogeologic system beneath Pahute Mesa, the U.S....
Garcia, C. Amanda; Jackson, Tracie R.; Halford, Keith J.; Sweetkind, Donald S.; Damar, Nancy A.; Fenelon, Joseph M.; Reiner, Steven R. Testing the suitability of geologic frameworks for extrapolating hydraulic properties across regional scales
The suitability of geologic frameworks for extrapolating hydraulic conductivity (K) to length scales commensurate with hydraulic data is difficult to assess. A novel method is presented for evaluating assumed relations between K and geologic interpretations for regional-scale groundwater modeling. The approach relies on simultaneous...
Mirus, Benjamin B.; Halford, Keith J.; Sweetkind, Donald S.; Fenelon, Joseph M.
T-COMP—A suite of programs for extracting transmissivity from MODFLOW models
Simulated transmissivities are constrained poorly by assigning permissible ranges of hydraulic conductivities from aquifer-test results to hydrogeologic units in groundwater-flow models. These wide ranges are derived from interpretations of many aquifer tests that are categorized by hydrogeologic unit. Uncertainty is added where contributing...
Halford, Keith J.
Delineation of the Pahute Mesa–Oasis Valley groundwater basin, Nevada
This report delineates the Pahute Mesa–Oasis Valley (PMOV) groundwater basin, where recharge occurs, moves downgradient, and discharges to Oasis Valley, Nevada. About 5,900 acre-feet of water discharges annually from Oasis Valley, an area of springs and seeps near the town of Beatty in southern Nevada. Radionuclides in groundwater beneath Pahute...
Fenelon, Joseph M.; Halford, Keith J.; Moreo, Michael T.
Evaluating connection of aquifers to springs and streams, Great Basin National Park and vicinity, Nevada
Federal agencies that oversee land management for much of the Snake Range in eastern Nevada, including the management of Great Basin National Park by the National Park Service, need to understand the potential extent of adverse effects to federally managed lands from nearby groundwater development. As a result, this study was developed (1) to...
Prudic, David E.; Sweetkind, Donald S.; Jackson, Tracie R.; Dotson, K. Elaine; Plume, Russell W.; Hatch, Christine E.; Halford, Keith J.
SeriesSEE
SeriesSEE is a spreadsheet add-in for viewing time series and modeling water levels that was developed in Microsoft Excel 2010.
FLASH: A Computer Program for Flow-Log Analysis of Single Holes
FLASH (Flow-Log Analysis of Single Holes) is a computer program for the analysis of borehole vertical flow logs.
AnalyzeHOLE
AnalyzeHOLE, an integrated wellbore analysis tool for simulating flow and transport in wells and aquifer systems, provides a better alternative for simulating and evaluating complex well-aquifer system interaction.