Science and Products
Filter Total Items: 36
Critical aquifer overdraft accelerates degradation of groundwater quality in California’s Central Valley during drought
Drought-induced pumpage has precipitated dramatic groundwater-level declines in California’s Central Valley over the past 30 years, but the impacts of aquifer overdraft on water quality are poorly understood. This study coupled over 160,000 measurements of nitrate from ∼6,000 public-supply wells with a 30-year reconstruction of groundwater levels throughout the Central Valley to evaluate dynamic r
Authors
Zeno Levy, Bryant Jurgens, Karen R. Burow, Stefan Voss, Kirsten Faulkner, Jose Alfredo Arroyo-Lopez, Miranda S. Fram
Using age tracers and decadal sampling to discern trends in nitrate, arsenic and uranium in groundwater beneath irrigated cropland
Repeat sampling and age tracers were used to examine trends in nitrate, arsenic and uranium concentrations in groundwater beneath irrigated cropland. Much higher nitrate concentrations in shallow modern groundwater were observed at both the Columbia Plateau and High Plains sites (median values of 10.2 and 15.4 mg/L as N, respectively) than in groundwater that recharged prior to the onset of intens
Authors
Anthony J. Tesoriero, Karen R. Burow, Lonna Frans, Jonathan V. Haynes, Christopher M. Hobza, Bruce D. Lindsey, John E. Solder
Anthropogenic and geologic causes of anomalously high uranium concentrations in groundwater used for drinking water supply in the southeastern San Joaquin Valley, CA
Concentrations of uranium (U) >30 µg/L in groundwater are relatively uncommon in drinking water in the United States but can be of concern in those areas where complex interactions of aquifer materials and anthropogenic alterations of the natural flow regime mobilize uranium. High concentrations (>30 µg/L) of U in the southeastern San Joaquin Valley, California, USA, have been detected in 24 perc
Authors
Michael R. Rosen, Karen R. Burow, Miranda Fram
Large decadal-scale changes in uranium and bicarbonate in groundwater of the irrigated western U.S
Samples collected about one decade apart from 1105 wells from across the U.S. were compiled to assess whether uranium concentrations in the arid climate are linked to changing bicarbonate concentrations in the irrigated western U.S. Uranium concentrations in groundwater were high in the arid climate in the western U.S, where uranium sources are abundant. Sixty-four wells (6%) were above the U.S. E
Authors
Karen R. Burow, Kenneth Belitz, Neil M. Dubrovsky, Bryant C. Jurgens
Factors affecting temporal variability of arsenic in groundwater used for drinking water supply in the United States
The occurrence of arsenic in groundwater is a recognized environmental hazard with worldwide importance and much effort has been focused on surveying and predicting where arsenic occurs. Temporal variability is one aspect of this environmental hazard that has until recently received less attention than other aspects. For this study, we analyzed 1245 wells with two samples per well. We suggest that
Authors
Joseph D. Ayotte, Marcel Belaval, Scott A. Olson, Karen R. Burow, Sarah M. Flanagan, Stephen R. Hinkle, Bruce D. Lindsey
Groundwater studies: principal aquifer surveys
In 1991, the U.S. Congress established the National Water-Quality Assessment (NAWQA) program within the U.S. Geological Survey (USGS) to develop nationally consistent long-term datasets and provide information about the quality of the Nation’s streams and groundwater. The USGS uses objective and reliable data, water-quality models, and systematic scientific studies to assess current water-quality
Authors
Karen R. Burow, Kenneth Belitz
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
The quality of our nation's waters: Nutrients in the nation's streams and groundwater, 1992-2004
National Findings and Their ImplicationsAlthough the use of artificial fertilizer has supported increasing food production to meet the needs of a growing population, increases in nutrient loadings from agricultural and, to a lesser extent, urban sources have resulted in nutrient concentrations in many streams and parts of aquifers that exceed standards for protection of human health and (or) aquat
Authors
Neil M. Dubrovsky, Karen R. Burow, Gregory M. Clark, JoAnn M. Gronberg, Pixie A. Hamilton, Kerie J. Hitt, David K. Mueller, Mark D. Munn, Bernard T. Nolan, Larry J. Puckett, Michael G. Rupert, Terry M. Short, Norman E. Spahr, Lori A. Sprague, William G. Wilber
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
Nitrate in groundwater of the United States, 1991-2003
An assessment of nitrate concentrations in groundwater in the United States indicates that concentrations are highest in shallow, oxic groundwater beneath areas with high N inputs. During 1991-2003, 5101 wells were sampled in 51 study areas throughout the U.S. as part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) program. The well networks reflect the existing used resour
Authors
Karen R. Burow, Bernard T. Nolan, Michael G. Rupert, Neil M. Dubrovsky
Assessing the Vulnerability of Public-Supply Wells to Contamination: Central Valley Aquifer System near Modesto, California
This fact sheet highlights findings from the vulnerability study of a public-supply well in Modesto, California. The well selected for study pumps on average about 1,600 gallons per minute from the Central Valley aquifer system during peak summer demand. Water samples were collected at the public-supply well and at monitoring wells installed in the Modesto vicinity. Samples from the public-supply
Authors
Martha L. Jagucki, Bryant C. Jurgens, Karen R. Burow, Sandra M. Eberts
Effects of Groundwater Development on Uranium: Central Valley, California, USA
Uranium (U) concentrations in groundwater in several parts of the eastern San Joaquin Valley, California, have exceeded federal and state drinking water standards during the last 20 years. The San Joaquin Valley is located within the Central Valley of California and is one of the most productive agricultural areas in the world. Increased irrigation and pumping associated with agricultural and urba
Authors
Bryant C. Jurgens, Miranda S. Fram, Kenneth Belitz, Karen R. Burow, Matthew K. Landon
Science and Products
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Filter Total Items: 36
Critical aquifer overdraft accelerates degradation of groundwater quality in California’s Central Valley during drought
Drought-induced pumpage has precipitated dramatic groundwater-level declines in California’s Central Valley over the past 30 years, but the impacts of aquifer overdraft on water quality are poorly understood. This study coupled over 160,000 measurements of nitrate from ∼6,000 public-supply wells with a 30-year reconstruction of groundwater levels throughout the Central Valley to evaluate dynamic rAuthorsZeno Levy, Bryant Jurgens, Karen R. Burow, Stefan Voss, Kirsten Faulkner, Jose Alfredo Arroyo-Lopez, Miranda S. FramUsing age tracers and decadal sampling to discern trends in nitrate, arsenic and uranium in groundwater beneath irrigated cropland
Repeat sampling and age tracers were used to examine trends in nitrate, arsenic and uranium concentrations in groundwater beneath irrigated cropland. Much higher nitrate concentrations in shallow modern groundwater were observed at both the Columbia Plateau and High Plains sites (median values of 10.2 and 15.4 mg/L as N, respectively) than in groundwater that recharged prior to the onset of intensAuthorsAnthony J. Tesoriero, Karen R. Burow, Lonna Frans, Jonathan V. Haynes, Christopher M. Hobza, Bruce D. Lindsey, John E. SolderAnthropogenic and geologic causes of anomalously high uranium concentrations in groundwater used for drinking water supply in the southeastern San Joaquin Valley, CA
Concentrations of uranium (U) >30 µg/L in groundwater are relatively uncommon in drinking water in the United States but can be of concern in those areas where complex interactions of aquifer materials and anthropogenic alterations of the natural flow regime mobilize uranium. High concentrations (>30 µg/L) of U in the southeastern San Joaquin Valley, California, USA, have been detected in 24 percAuthorsMichael R. Rosen, Karen R. Burow, Miranda FramLarge decadal-scale changes in uranium and bicarbonate in groundwater of the irrigated western U.S
Samples collected about one decade apart from 1105 wells from across the U.S. were compiled to assess whether uranium concentrations in the arid climate are linked to changing bicarbonate concentrations in the irrigated western U.S. Uranium concentrations in groundwater were high in the arid climate in the western U.S, where uranium sources are abundant. Sixty-four wells (6%) were above the U.S. EAuthorsKaren R. Burow, Kenneth Belitz, Neil M. Dubrovsky, Bryant C. JurgensFactors affecting temporal variability of arsenic in groundwater used for drinking water supply in the United States
The occurrence of arsenic in groundwater is a recognized environmental hazard with worldwide importance and much effort has been focused on surveying and predicting where arsenic occurs. Temporal variability is one aspect of this environmental hazard that has until recently received less attention than other aspects. For this study, we analyzed 1245 wells with two samples per well. We suggest thatAuthorsJoseph D. Ayotte, Marcel Belaval, Scott A. Olson, Karen R. Burow, Sarah M. Flanagan, Stephen R. Hinkle, Bruce D. LindseyGroundwater studies: principal aquifer surveys
In 1991, the U.S. Congress established the National Water-Quality Assessment (NAWQA) program within the U.S. Geological Survey (USGS) to develop nationally consistent long-term datasets and provide information about the quality of the Nation’s streams and groundwater. The USGS uses objective and reliable data, water-quality models, and systematic scientific studies to assess current water-qualityAuthorsKaren R. Burow, Kenneth BelitzAssessment 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 generallyAuthorsKaren R. Burow, Bryant C. Jurgens, Kenneth Belitz, Neil M. DubrovskyThe quality of our nation's waters: Nutrients in the nation's streams and groundwater, 1992-2004
National Findings and Their ImplicationsAlthough the use of artificial fertilizer has supported increasing food production to meet the needs of a growing population, increases in nutrient loadings from agricultural and, to a lesser extent, urban sources have resulted in nutrient concentrations in many streams and parts of aquifers that exceed standards for protection of human health and (or) aquatAuthorsNeil M. Dubrovsky, Karen R. Burow, Gregory M. Clark, JoAnn M. Gronberg, Pixie A. Hamilton, Kerie J. Hitt, David K. Mueller, Mark D. Munn, Bernard T. Nolan, Larry J. Puckett, Michael G. Rupert, Terry M. Short, Norman E. Spahr, Lori A. Sprague, William G. WilberDepth-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-dependenAuthorsMatthew K. Landon, Bryant C. Jurgens, Brian G. Katz, Sandra M. Eberts, Karen R. Burow, Christy A. CrandallNitrate in groundwater of the United States, 1991-2003
An assessment of nitrate concentrations in groundwater in the United States indicates that concentrations are highest in shallow, oxic groundwater beneath areas with high N inputs. During 1991-2003, 5101 wells were sampled in 51 study areas throughout the U.S. as part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) program. The well networks reflect the existing used resourAuthorsKaren R. Burow, Bernard T. Nolan, Michael G. Rupert, Neil M. DubrovskyAssessing the Vulnerability of Public-Supply Wells to Contamination: Central Valley Aquifer System near Modesto, California
This fact sheet highlights findings from the vulnerability study of a public-supply well in Modesto, California. The well selected for study pumps on average about 1,600 gallons per minute from the Central Valley aquifer system during peak summer demand. Water samples were collected at the public-supply well and at monitoring wells installed in the Modesto vicinity. Samples from the public-supplyAuthorsMartha L. Jagucki, Bryant C. Jurgens, Karen R. Burow, Sandra M. EbertsEffects of Groundwater Development on Uranium: Central Valley, California, USA
Uranium (U) concentrations in groundwater in several parts of the eastern San Joaquin Valley, California, have exceeded federal and state drinking water standards during the last 20 years. The San Joaquin Valley is located within the Central Valley of California and is one of the most productive agricultural areas in the world. Increased irrigation and pumping associated with agricultural and urbaAuthorsBryant C. Jurgens, Miranda S. Fram, Kenneth Belitz, Karen R. Burow, Matthew K. Landon