Bryant C Jurgens
Groundwater is an important source of drinking water in the United States. In order to assess the status and long-term sustainability of this important resource, I use environmental tracers, geochemical modeling, and statistical methods to understand the age structure, geochemical processes, and trends affecting water-quality in aquifers.
Science and Products
Filter Total Items: 14
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Filter Total Items: 56
Effects of seasonal operation on the quality of water produced by public-supply wells
Seasonal variability in groundwater pumping is common in many places, but resulting effects of seasonal pumping stress on the quality of water produced by public-supply wells are not thoroughly understood. Analysis of historical water-quality samples from public-supply wells completed in deep basin-fill aquifers in Modesto, California (134 wells) and Albuquerque, New Mexico (95 wells) indicates th
Authors
Laura M. Bexfield, Bryant C. Jurgens
A ternary age-mixing model to explain contaminant occurrence in a deep supply well
The age distribution of water from a public-supply well in a deep alluvial aquifer was estimated and used to help explain arsenic variability in the water. The age distribution was computed using a ternary mixing model that combines three lumped parameter models of advection-dispersion transport of environmental tracers, which represent relatively recent recharge (post- 1950s) containing volatile
Authors
Bryant C. Jurgens, Laura M. Bexfield, Sandra M. Eberts
Educational webtool illustrating groundwater age effects on contaminant trends in wells
No abstract available.
Authors
John Karl Böhlke, Bryant C. Jurgens, David J. Uselmann, Sandra M. Eberts
Accuracy of travel time distribution (TTD) models as affected by TTD complexity, observation errors, and model and tracer selection
Analytical models of the travel time distribution (TTD) from a source area to a sample location are often used to estimate groundwater ages and solute concentration trends. The accuracies of these models are not well known for geologically complex aquifers. In this study, synthetic datasets were used to quantify the accuracy of four analytical TTD models as affected by TTD complexity, observation
Authors
Christopher T. Green, Yong Zhang, Bryant C. Jurgens, J. Jeffrey Starn, Matthew K. Landon
Assessment of regional change in nitrate concentrations in groundwater in the Central Valley, California, USA, 1950s-2000s
A regional assessment of multi-decadal changes in nitrate concentrations was done using historical data and a spatially stratified non-biased approach. Data were stratified into physiographic subregions on the basis of geomorphology and soils data to represent zones of historical recharge and discharge patterns in the basin. Data were also stratified by depth to represent a shallow zone generally
Authors
Karen R. Burow, Bryant C. Jurgens, Kenneth Belitz, Neil M. Dubrovsky
Status and understanding of groundwater quality in the Madera, Chowchilla Study Unit, 2008: California GAMA Priority Basin Project
Groundwater quality in the approximately 860-square-mile Madera and Chowchilla Subbasins (Madera-Chowchilla study unit) of the San Joaquin Valley Basin was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is located in California's Central Valley region in parts of Madera, Merced, and Fresno Counties. The GAMA Pr
Authors
Jennifer L. Shelton, Miranda S. Fram, Kenneth Belitz, Bryant C. Jurgens
TracerLPM (Version 1): An Excel® workbook for interpreting groundwater age distributions from environmental tracer data
TracerLPM is an interactive Excel® (2007 or later) workbook program for evaluating groundwater age distributions from environmental tracer data by using lumped parameter models (LPMs). Lumped parameter models are mathematical models of transport based on simplified aquifer geometry and flow configurations that account for effects of hydrodynamic dispersion or mixing within the aquifer, well bore,
Authors
Bryant C. Jurgens, J.K. Böhlke, Sandra M. Eberts
Hydrogeology, water chemistry, and transport processes in the zone of contribution of a public-supply well in Albuquerque, New Mexico, 2007-9
The National Water-Quality Assessment Program (NAWQA) of the U.S. Geological Survey began a series of groundwater studies in 2001 in representative aquifers across the Nation in order to increase understanding of the factors that affect transport of anthropogenic and natural contaminants (TANC) to public-supply wells. One of 10 regional-scale TANC studies was conducted in the Middle Rio Grande Bas
Authors
Laura M. Bexfield, Bryant C. Jurgens, Dianna M. Crilley, Scott C. Christenson
Comparison of particle-tracking and lumped-parameter age-distribution models for evaluating vulnerability of production wells to contamination
Environmental age tracers have been used in various ways to help assess vulnerability of drinking-water production wells to contamination. The most appropriate approach will depend on the information that is available and that which is desired. To understand how the well will respond to changing nonpoint-source contaminant inputs at the water table, some representation of the distribution of groun
Authors
S. M. Eberts, J.K. Böhlke, L. J. Kauffman, B.C. Jurgens
Status and understanding of groundwater quality in the northern San Joaquin Basin, 2005: California GAMA Priority Basin Project
Groundwater quality in the 2,079 square mile Northern San Joaquin Basin (Northern San Joaquin) study unit was investigated from December 2004 through February 2005 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project was developed in response to the Groundwater Quality Monitoring Act of 2001 that was passed by th
Authors
George L. Bennett V, Miranda S. Fram, Kenneth Belitz, Bryant C. Jurgens
Depth-dependent sampling to identify short-circuit pathways to public-supply wells in multiple aquifer settings in the United States
Depth-dependent water-quality and borehole flow data were used to determine where and how contamination enters public-supply wells (PSWs) at study sites in different principal aquifers of the United States. At each of three study sites, depth-dependent samples and wellbore flow data were collected from multiple depths in selected PSWs under pumping conditions. The chemistry of these depth-dependen
Authors
Matthew K. Landon, Bryant C. Jurgens, Brian G. Katz, Sandra M. Eberts, Karen R. Burow, Christy A. Crandall
Status and understanding of groundwater quality in the central-eastside San Joaquin Basin, 2006: California GAMA Priority Basin Project
Groundwater quality in the approximately 1,695-square-mile Central Eastside San Joaquin Basin (Central Eastside) study unit was investigated as part of the Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001, and is being conducted by the California Stat
Authors
Matthew K. Landon, Kenneth Belitz, Bryant C. Jurgens, Justin T. Kulongoski, Tyler D. Johnson
Science and Products
Filter Total Items: 14
No Result Found
Filter Total Items: 56
Effects of seasonal operation on the quality of water produced by public-supply wells
Seasonal variability in groundwater pumping is common in many places, but resulting effects of seasonal pumping stress on the quality of water produced by public-supply wells are not thoroughly understood. Analysis of historical water-quality samples from public-supply wells completed in deep basin-fill aquifers in Modesto, California (134 wells) and Albuquerque, New Mexico (95 wells) indicates th
Authors
Laura M. Bexfield, Bryant C. Jurgens
A ternary age-mixing model to explain contaminant occurrence in a deep supply well
The age distribution of water from a public-supply well in a deep alluvial aquifer was estimated and used to help explain arsenic variability in the water. The age distribution was computed using a ternary mixing model that combines three lumped parameter models of advection-dispersion transport of environmental tracers, which represent relatively recent recharge (post- 1950s) containing volatile
Authors
Bryant C. Jurgens, Laura M. Bexfield, Sandra M. Eberts
Educational webtool illustrating groundwater age effects on contaminant trends in wells
No abstract available.
Authors
John Karl Böhlke, Bryant C. Jurgens, David J. Uselmann, Sandra M. Eberts
Accuracy of travel time distribution (TTD) models as affected by TTD complexity, observation errors, and model and tracer selection
Analytical models of the travel time distribution (TTD) from a source area to a sample location are often used to estimate groundwater ages and solute concentration trends. The accuracies of these models are not well known for geologically complex aquifers. In this study, synthetic datasets were used to quantify the accuracy of four analytical TTD models as affected by TTD complexity, observation
Authors
Christopher T. Green, Yong Zhang, Bryant C. Jurgens, J. Jeffrey Starn, Matthew K. Landon
Assessment of regional change in nitrate concentrations in groundwater in the Central Valley, California, USA, 1950s-2000s
A regional assessment of multi-decadal changes in nitrate concentrations was done using historical data and a spatially stratified non-biased approach. Data were stratified into physiographic subregions on the basis of geomorphology and soils data to represent zones of historical recharge and discharge patterns in the basin. Data were also stratified by depth to represent a shallow zone generally
Authors
Karen R. Burow, Bryant C. Jurgens, Kenneth Belitz, Neil M. Dubrovsky
Status and understanding of groundwater quality in the Madera, Chowchilla Study Unit, 2008: California GAMA Priority Basin Project
Groundwater quality in the approximately 860-square-mile Madera and Chowchilla Subbasins (Madera-Chowchilla study unit) of the San Joaquin Valley Basin was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is located in California's Central Valley region in parts of Madera, Merced, and Fresno Counties. The GAMA Pr
Authors
Jennifer L. Shelton, Miranda S. Fram, Kenneth Belitz, Bryant C. Jurgens
TracerLPM (Version 1): An Excel® workbook for interpreting groundwater age distributions from environmental tracer data
TracerLPM is an interactive Excel® (2007 or later) workbook program for evaluating groundwater age distributions from environmental tracer data by using lumped parameter models (LPMs). Lumped parameter models are mathematical models of transport based on simplified aquifer geometry and flow configurations that account for effects of hydrodynamic dispersion or mixing within the aquifer, well bore,
Authors
Bryant C. Jurgens, J.K. Böhlke, Sandra M. Eberts
Hydrogeology, water chemistry, and transport processes in the zone of contribution of a public-supply well in Albuquerque, New Mexico, 2007-9
The National Water-Quality Assessment Program (NAWQA) of the U.S. Geological Survey began a series of groundwater studies in 2001 in representative aquifers across the Nation in order to increase understanding of the factors that affect transport of anthropogenic and natural contaminants (TANC) to public-supply wells. One of 10 regional-scale TANC studies was conducted in the Middle Rio Grande Bas
Authors
Laura M. Bexfield, Bryant C. Jurgens, Dianna M. Crilley, Scott C. Christenson
Comparison of particle-tracking and lumped-parameter age-distribution models for evaluating vulnerability of production wells to contamination
Environmental age tracers have been used in various ways to help assess vulnerability of drinking-water production wells to contamination. The most appropriate approach will depend on the information that is available and that which is desired. To understand how the well will respond to changing nonpoint-source contaminant inputs at the water table, some representation of the distribution of groun
Authors
S. M. Eberts, J.K. Böhlke, L. J. Kauffman, B.C. Jurgens
Status and understanding of groundwater quality in the northern San Joaquin Basin, 2005: California GAMA Priority Basin Project
Groundwater quality in the 2,079 square mile Northern San Joaquin Basin (Northern San Joaquin) study unit was investigated from December 2004 through February 2005 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project was developed in response to the Groundwater Quality Monitoring Act of 2001 that was passed by th
Authors
George L. Bennett V, Miranda S. Fram, Kenneth Belitz, Bryant C. Jurgens
Depth-dependent sampling to identify short-circuit pathways to public-supply wells in multiple aquifer settings in the United States
Depth-dependent water-quality and borehole flow data were used to determine where and how contamination enters public-supply wells (PSWs) at study sites in different principal aquifers of the United States. At each of three study sites, depth-dependent samples and wellbore flow data were collected from multiple depths in selected PSWs under pumping conditions. The chemistry of these depth-dependen
Authors
Matthew K. Landon, Bryant C. Jurgens, Brian G. Katz, Sandra M. Eberts, Karen R. Burow, Christy A. Crandall
Status and understanding of groundwater quality in the central-eastside San Joaquin Basin, 2006: California GAMA Priority Basin Project
Groundwater quality in the approximately 1,695-square-mile Central Eastside San Joaquin Basin (Central Eastside) study unit was investigated as part of the Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001, and is being conducted by the California Stat
Authors
Matthew K. Landon, Kenneth Belitz, Bryant C. Jurgens, Justin T. Kulongoski, Tyler D. Johnson