Bill Eldridge
Hydrologist for the Dakota Water Science Center
Bill Eldridge is a hydrologist at the Dakota Water Science Center. He received a Bachelor and Master degrees in Geological Engineering from the South Dakota School of Mines and Technology. He also has a Bachelor degree in Chemistry from the U.S. Air Force Academy. Since joining the USGS in 2013, Bill studies Black Hills hydrology and groundwater modeling.
Science and Products
Simulation of Groundwater Flow in the Madison and Minnelusa Aquifers, Black Hills Area
Project Period: 2011-2018 Cooperator: National Park Service, Black Hills National Forest, City of Rapid City, West Dakota Water Development District Project Chief: Bill Eldridge
Three-Dimensional Delineation of the Pierre Shale Bedrock from Electrical Resistivity Surveys Conducted in Two Areas of Interest Within and Near Ellsworth Air Force Base, South Dakota, 2022
In 2022, the USGS, in cooperation with the U.S. Air Force Civil Engineer Center (USAF/CEC), performed geophysical surveys at two areas of interest within and near Ellsworth Air Force Base (EAFB) to delineate the Cretaceous Pierre Shale bedrock. Electrical resistivity tomography (ERT) data were collected in two grid patterns using the dipole-dipole array within and near EAFB and site information—in
Electrical resistivity tomography, electromagnetic induction, and ultraviolet optical scanning tool data collected at Malmstrom Air Force Base, Great Falls, Montana, August 28–August 31, 2023
The U.S. Geological Survey (USGS), in cooperation with the U.S. Air Force Civil Engineer Center (USAF/CEC), conducted a pilot study at Malmstrom Air Force Base (MAFB) to evaluate the utility of two non-invasive geophysical techniques for detecting hydrocarbons in subsurface materials. Electrical resistivity tomography (ERT) and electromagnetic induction (EMI) surveys were completed August 28–29, 2
Datasets Used to Create Maps of Pierre Shale Elevation and Surficial Deposit Thickness within and near Ellsworth Air Force Base, South Dakota, 2021
This data release contains borehole geophysical data collected within and near Ellsworth Air Force Base, South Dakota, from September 2020 to August 2021. The data accompanies a USGS scientific investigations map from Medler and others (2022). The U.S. Geological Survey, in cooperation with the U.S. Air Force Civil Engineer Center, collected borehole geophysical data and performed simple aquifer
Borehole Video and Aquifer Test Data for the Burnpit Well, Mount Rushmore National Memorial, South Dakota, 2020
This data release contains borehole video and aquifer-test data for the Burnpit well (U.S. Geological Survey [USGS] National Water Information System identification 435240103265301), Mount Rushmore National Memorial, collected in June and July 2020. The data accompany a USGS Scientific Investigations Report by Eldridge and others (2021).
Soil-Water Balance model for alluvial deposits in Summerset, South Dakota
A Soil-Water Balance (SWB) model of the alluvial aquifer in north Summerset, South Dakota, was constructed to estimate recharge and potential evapotranspiration volumes and rates for 2017-19. The model area included the northern part of the city of Summerset in west South Dakota along the east range of the Black Hills. The model area was defined as a rectangular area that included the watershed bo
MODFLOW-6 model of the Big Sioux aquifer, Sioux Falls, South Dakota
A MODFLOW-6 groundwater flow model of the Big Sioux aquifer near Sioux Falls in southeastern South Dakota, was constructed to improve the understanding and management of the water supply resources for the City of Sioux Falls.
Water-level data and AQTESOLV Pro analysis results for slug tests in the Big Sioux Aquifer, Sioux Falls, South Dakota, 2017
Well and aquifer data were collected from field measurements and drillers' logs. Multiple slug tests were completed at each well with a transducer to record the change in water level and a U.S. Geological Survey standard mechanical slug to displace the well's water column. A Solinst Levelogger LT F30/M10 electronic transducer (unvented) was used to record water-level changes during each slug test.
MODFLOW-NWT model of the glacial aquifer system north of Aberdeen, South Dakota, through water year 2015
A previously developed three-dimensional groundwater flow model (https://doi.org/10.3133/sir20125183) of the three primary aquifers in the region north of Aberdeen, South Dakota, was revised to assist the City of Aberdeen with water-resource planning. The principal aquifers are the Elm, Middle James, and Deep James. The numerical model is intended to be used to (1) simulate hydrologic scenarios o
Maps of elevation of top of Pierre Shale and surficial deposit thickness with hydraulic properties from borehole geophysics and aquifers tests within and near Ellsworth Air Force Base, South Dakota, 2020–21
The U.S. Geological Survey, in cooperation with the U.S. Air Force Civil Engineer Center, collected borehole geophysical data and completed simple aquifer tests to estimate the thickness and hydraulic properties of surficial deposits. The purpose of data collection was to create generalized contour maps of Pierre Shale elevation and surficial deposit thickness within and near Ellsworth Air Force B
Stratigraphic units of shallow unconsolidated deposits in Deadwood, South Dakota, delineated by real-time kinematic surveys
The City of Deadwood, South Dakota, has been working on a new archeological investigation in preparation for economic growth and expansion within the city limits, through the Deadwood Historic Preservation Office. During the excavation process, buried artifacts and historical features from the late 1800s have been uncovered. The stratigraphy of shallow unconsolidated deposits in the city of Deadwo
Borehole analysis, single-well aquifer testing, and water quality for the Burnpit well, Mount Rushmore National Memorial, South Dakota
Mount Rushmore National Memorial (hereafter referred to as “the memorial”), in western South Dakota, is maintained by the National Park Service (NPS) and includes 1,278 acres of land in the east-central part of the Black Hills. An ongoing challenge for NPS managers at the memorial is providing water from sustainable and reliable sources for operations, staff, and the increasing number of visitors.
Authors
William G. Eldridge, Galen K. Hoogestraat, Steven E. Rice
Spring types and contributing aquifers from water-chemistry and multivariate statistical analyses for seeps and springs in Theodore Roosevelt National Park, North Dakota, 2018
Water resources in Theodore Roosevelt National Park, North Dakota, support wildlife, visitors, and staff, and play a vital role in supporting the native ecology of the park. The U.S. Geological Survey, in cooperation with the National Park Service, completed field work in 2018 for a study to address concerns about water availability and possible sources of groundwater contamination for seeps and s
Authors
Colton J. Medler, William G. Eldridge
Hydrogeology and groundwater flow in alluvial deposits, north Summerset, South Dakota
The city of Summerset is a growing community in west South Dakota. The Sun Valley Estates subdivision in the north part of the city was developed on unconsolidated deposits surrounded by steep terrain. During years with greater than normal precipitation, particularly in 2019, groundwater levels increased in the unconsolidated deposits and caused damage to stormwater systems, sewer infrastructure,
Authors
William G. Eldridge, Todd M. Anderson
Inventory and analysis of groundwater resources: Theodore Roosevelt National Park, North Dakota
Industrial and commercial developments in western North Dakota potentially could affect the sources of water that contribute to wells, spring flow, and seeps within Theodore Roosevelt National Park. Without basic water resources data, accurately predicting the effects of water withdrawals and water quality concerns related to industrial and commercial developments near the park would be challengin
Authors
William G. Eldridge, Colton J. Medler
Groundwater-flow model and analysis of groundwater and surface-water interactions for the Big Sioux aquifer, Sioux Falls, South Dakota
The city of Sioux Falls, in southeastern South Dakota, is the largest city in South Dakota. The U.S. Geological Survey (USGS), in cooperation with the city of Sioux Falls, completed a groundwater-flow model to use for improving the understanding of groundwater-flow processes, estimating hydrogeologic properties, and analyzing groundwater and surface-water interactions for the Big Sioux aquifer in
Authors
Kyle W. Davis, William G. Eldridge, Joshua F. Valder, Kristen J. Valseth
Multivariate analysis of hydrochemical data for Jewel Cave, Wind Cave, and surrounding areas
Jewel Cave National Monument and Wind Cave National Park in South Dakota contain two of the six longest caves worldwide. These caves contain subterranean lakes that are important points of intersection between the water table of the Madison aquifer and the caves. During 2015 to 2017, several subterranean lakes were discovered in Jewel Cave, which previously was thought to be above the regional wat
Authors
Andrew J. Long, James B. Paces, William G. Eldridge
Generalized potentiometric-surface map and groundwater flow directions in the Madison aquifer near Jewel Cave National Monument, South Dakota
A generalized potentiometric-surface map of the Madison aquifer near Jewel Cave National Monument was constructed using water levels measured from calendar years 1988 to 2019 in 24 groundwater wells and 4 subterranean cave lakes interpreted to be in hydraulic connection with the aquifer. The map indicated that groundwater near Jewel Cave National Monument originates from recharge sources to the Ma
Authors
Todd M. Anderson, William G. Eldridge, Joshua F. Valder, Michael E. Wiles
Hydraulic conductivity estimates from slug tests in the Big Sioux aquifer near Sioux Falls, South Dakota
Hydraulic conductivity estimates were made for 15 observation wells using slug-out (rising-head) tests in the Big Sioux aquifer near Sioux Falls, South Dakota, as part of a cooperative study with the City of Sioux Falls to characterize the hydrogeology and the extent of the Big Sioux aquifer north of the city. Well and aquifer data were collected from field measurements and drillers’ logs. Multipl
Authors
William G. Eldridge, Colton J. Medler
Revised groundwater-flow model of the glacial aquifer system north of Aberdeen, South Dakota, through water year 2015
The city of Aberdeen, in northeastern South Dakota, requires an expanded and sustainable supply of water to meet current and future demands. Conceptual and numerical models of the glacial aquifer system in the area north of Aberdeen were developed by the U.S. Geological Survey in cooperation with the City of Aberdeen in 2012. The U.S. Geological Survey, in cooperation with the City of Aberdeen, co
Authors
Joshua F. Valder, William G. Eldridge, Kyle W. Davis, Colton J. Medler, Karl R. Koth
Science and Products
Simulation of Groundwater Flow in the Madison and Minnelusa Aquifers, Black Hills Area
Project Period: 2011-2018 Cooperator: National Park Service, Black Hills National Forest, City of Rapid City, West Dakota Water Development District Project Chief: Bill Eldridge
Three-Dimensional Delineation of the Pierre Shale Bedrock from Electrical Resistivity Surveys Conducted in Two Areas of Interest Within and Near Ellsworth Air Force Base, South Dakota, 2022
In 2022, the USGS, in cooperation with the U.S. Air Force Civil Engineer Center (USAF/CEC), performed geophysical surveys at two areas of interest within and near Ellsworth Air Force Base (EAFB) to delineate the Cretaceous Pierre Shale bedrock. Electrical resistivity tomography (ERT) data were collected in two grid patterns using the dipole-dipole array within and near EAFB and site information—in
Electrical resistivity tomography, electromagnetic induction, and ultraviolet optical scanning tool data collected at Malmstrom Air Force Base, Great Falls, Montana, August 28–August 31, 2023
The U.S. Geological Survey (USGS), in cooperation with the U.S. Air Force Civil Engineer Center (USAF/CEC), conducted a pilot study at Malmstrom Air Force Base (MAFB) to evaluate the utility of two non-invasive geophysical techniques for detecting hydrocarbons in subsurface materials. Electrical resistivity tomography (ERT) and electromagnetic induction (EMI) surveys were completed August 28–29, 2
Datasets Used to Create Maps of Pierre Shale Elevation and Surficial Deposit Thickness within and near Ellsworth Air Force Base, South Dakota, 2021
This data release contains borehole geophysical data collected within and near Ellsworth Air Force Base, South Dakota, from September 2020 to August 2021. The data accompanies a USGS scientific investigations map from Medler and others (2022). The U.S. Geological Survey, in cooperation with the U.S. Air Force Civil Engineer Center, collected borehole geophysical data and performed simple aquifer
Borehole Video and Aquifer Test Data for the Burnpit Well, Mount Rushmore National Memorial, South Dakota, 2020
This data release contains borehole video and aquifer-test data for the Burnpit well (U.S. Geological Survey [USGS] National Water Information System identification 435240103265301), Mount Rushmore National Memorial, collected in June and July 2020. The data accompany a USGS Scientific Investigations Report by Eldridge and others (2021).
Soil-Water Balance model for alluvial deposits in Summerset, South Dakota
A Soil-Water Balance (SWB) model of the alluvial aquifer in north Summerset, South Dakota, was constructed to estimate recharge and potential evapotranspiration volumes and rates for 2017-19. The model area included the northern part of the city of Summerset in west South Dakota along the east range of the Black Hills. The model area was defined as a rectangular area that included the watershed bo
MODFLOW-6 model of the Big Sioux aquifer, Sioux Falls, South Dakota
A MODFLOW-6 groundwater flow model of the Big Sioux aquifer near Sioux Falls in southeastern South Dakota, was constructed to improve the understanding and management of the water supply resources for the City of Sioux Falls.
Water-level data and AQTESOLV Pro analysis results for slug tests in the Big Sioux Aquifer, Sioux Falls, South Dakota, 2017
Well and aquifer data were collected from field measurements and drillers' logs. Multiple slug tests were completed at each well with a transducer to record the change in water level and a U.S. Geological Survey standard mechanical slug to displace the well's water column. A Solinst Levelogger LT F30/M10 electronic transducer (unvented) was used to record water-level changes during each slug test.
MODFLOW-NWT model of the glacial aquifer system north of Aberdeen, South Dakota, through water year 2015
A previously developed three-dimensional groundwater flow model (https://doi.org/10.3133/sir20125183) of the three primary aquifers in the region north of Aberdeen, South Dakota, was revised to assist the City of Aberdeen with water-resource planning. The principal aquifers are the Elm, Middle James, and Deep James. The numerical model is intended to be used to (1) simulate hydrologic scenarios o
Maps of elevation of top of Pierre Shale and surficial deposit thickness with hydraulic properties from borehole geophysics and aquifers tests within and near Ellsworth Air Force Base, South Dakota, 2020–21
The U.S. Geological Survey, in cooperation with the U.S. Air Force Civil Engineer Center, collected borehole geophysical data and completed simple aquifer tests to estimate the thickness and hydraulic properties of surficial deposits. The purpose of data collection was to create generalized contour maps of Pierre Shale elevation and surficial deposit thickness within and near Ellsworth Air Force B
Stratigraphic units of shallow unconsolidated deposits in Deadwood, South Dakota, delineated by real-time kinematic surveys
The City of Deadwood, South Dakota, has been working on a new archeological investigation in preparation for economic growth and expansion within the city limits, through the Deadwood Historic Preservation Office. During the excavation process, buried artifacts and historical features from the late 1800s have been uncovered. The stratigraphy of shallow unconsolidated deposits in the city of Deadwo
Borehole analysis, single-well aquifer testing, and water quality for the Burnpit well, Mount Rushmore National Memorial, South Dakota
Mount Rushmore National Memorial (hereafter referred to as “the memorial”), in western South Dakota, is maintained by the National Park Service (NPS) and includes 1,278 acres of land in the east-central part of the Black Hills. An ongoing challenge for NPS managers at the memorial is providing water from sustainable and reliable sources for operations, staff, and the increasing number of visitors.
Authors
William G. Eldridge, Galen K. Hoogestraat, Steven E. Rice
Spring types and contributing aquifers from water-chemistry and multivariate statistical analyses for seeps and springs in Theodore Roosevelt National Park, North Dakota, 2018
Water resources in Theodore Roosevelt National Park, North Dakota, support wildlife, visitors, and staff, and play a vital role in supporting the native ecology of the park. The U.S. Geological Survey, in cooperation with the National Park Service, completed field work in 2018 for a study to address concerns about water availability and possible sources of groundwater contamination for seeps and s
Authors
Colton J. Medler, William G. Eldridge
Hydrogeology and groundwater flow in alluvial deposits, north Summerset, South Dakota
The city of Summerset is a growing community in west South Dakota. The Sun Valley Estates subdivision in the north part of the city was developed on unconsolidated deposits surrounded by steep terrain. During years with greater than normal precipitation, particularly in 2019, groundwater levels increased in the unconsolidated deposits and caused damage to stormwater systems, sewer infrastructure,
Authors
William G. Eldridge, Todd M. Anderson
Inventory and analysis of groundwater resources: Theodore Roosevelt National Park, North Dakota
Industrial and commercial developments in western North Dakota potentially could affect the sources of water that contribute to wells, spring flow, and seeps within Theodore Roosevelt National Park. Without basic water resources data, accurately predicting the effects of water withdrawals and water quality concerns related to industrial and commercial developments near the park would be challengin
Authors
William G. Eldridge, Colton J. Medler
Groundwater-flow model and analysis of groundwater and surface-water interactions for the Big Sioux aquifer, Sioux Falls, South Dakota
The city of Sioux Falls, in southeastern South Dakota, is the largest city in South Dakota. The U.S. Geological Survey (USGS), in cooperation with the city of Sioux Falls, completed a groundwater-flow model to use for improving the understanding of groundwater-flow processes, estimating hydrogeologic properties, and analyzing groundwater and surface-water interactions for the Big Sioux aquifer in
Authors
Kyle W. Davis, William G. Eldridge, Joshua F. Valder, Kristen J. Valseth
Multivariate analysis of hydrochemical data for Jewel Cave, Wind Cave, and surrounding areas
Jewel Cave National Monument and Wind Cave National Park in South Dakota contain two of the six longest caves worldwide. These caves contain subterranean lakes that are important points of intersection between the water table of the Madison aquifer and the caves. During 2015 to 2017, several subterranean lakes were discovered in Jewel Cave, which previously was thought to be above the regional wat
Authors
Andrew J. Long, James B. Paces, William G. Eldridge
Generalized potentiometric-surface map and groundwater flow directions in the Madison aquifer near Jewel Cave National Monument, South Dakota
A generalized potentiometric-surface map of the Madison aquifer near Jewel Cave National Monument was constructed using water levels measured from calendar years 1988 to 2019 in 24 groundwater wells and 4 subterranean cave lakes interpreted to be in hydraulic connection with the aquifer. The map indicated that groundwater near Jewel Cave National Monument originates from recharge sources to the Ma
Authors
Todd M. Anderson, William G. Eldridge, Joshua F. Valder, Michael E. Wiles
Hydraulic conductivity estimates from slug tests in the Big Sioux aquifer near Sioux Falls, South Dakota
Hydraulic conductivity estimates were made for 15 observation wells using slug-out (rising-head) tests in the Big Sioux aquifer near Sioux Falls, South Dakota, as part of a cooperative study with the City of Sioux Falls to characterize the hydrogeology and the extent of the Big Sioux aquifer north of the city. Well and aquifer data were collected from field measurements and drillers’ logs. Multipl
Authors
William G. Eldridge, Colton J. Medler
Revised groundwater-flow model of the glacial aquifer system north of Aberdeen, South Dakota, through water year 2015
The city of Aberdeen, in northeastern South Dakota, requires an expanded and sustainable supply of water to meet current and future demands. Conceptual and numerical models of the glacial aquifer system in the area north of Aberdeen were developed by the U.S. Geological Survey in cooperation with the City of Aberdeen in 2012. The U.S. Geological Survey, in cooperation with the City of Aberdeen, co
Authors
Joshua F. Valder, William G. Eldridge, Kyle W. Davis, Colton J. Medler, Karl R. Koth