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Groundwater from the Mississippi River Valley alluvial aquifer (MRVA) is a vital resource for agriculture and drinking-water supplies in the central United States. Water availability can be limited in some areas of the aquifer by high concentrations of trace elements, including manganese and arsenic. Boosted regression trees, a type of ensemble-tree machine-learning method, were used to predict manganese concentration and the probability of arsenic concentration exceeding a 10 µg/L threshold throughout the MRVA. Explanatory variables for the BRT models included attributes associated with well location and construction, surficial variables (such as hydrologic position and recharge), variables extracted from a MODFLOW-2005...
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Dataset contains the groundwater well locations and water-level measurements for 273 wells measured during a water-level survey of the Sparta-Memphis aquifer in Arkansas, January through June 2015. Well-location and water-level data is publicly available from the U.S. Geological Survey's National Water Information System.
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Groundwater is a vital resource to the Mississippi embayment region of the central United States. Regional and integrated assessments of water availability that link physical flow models and water quality in principal aquifer systems provide context for the long-term availability of these water resources. An innovative approach using machine learning was employed to predict groundwater pH across drinking water aquifers of the Mississippi embayment. The region includes two principal regional aquifer systems; the Mississippi River Valley alluvial (MRVA) aquifer and the Mississippi embayment aquifer system that includes several regional aquifers and confining units. Based on the distribution of groundwater use for...
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Groundwater is a vital resource in the Mississippi embayment of the central United States. An innovative approach using machine learning (ML) was employed to predict groundwater salinity—including specific conductance (SC), total dissolved solids (TDS), and chloride (Cl) concentrations—across three drinking-water aquifers of the Mississippi embayment. A ML approach was used because it accommodates a large and diverse set of explanatory variables, does not assume monotonic relations between predictors and response data, and results can be extrapolated to areas of the aquifer not sampled. These aspects of ML allowed potential drivers and sources of high salinity water that have been hypothesized in other studies to...
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Groundwater is a vital resource in the Mississippi embayment of the central United States. An innovative approach using machine learning (ML) was employed to predict groundwater salinity—including specific conductance (SC), total dissolved solids (TDS), and chloride (Cl) concentrations—across three drinking-water aquifers of the Mississippi embayment. A ML approach was used because it accommodates a large and diverse set of explanatory variables, does not assume monotonic relations between predictors and response data, and results can be extrapolated to areas of the aquifer not sampled. These aspects of ML allowed potential drivers and sources of high salinity water that have been hypothesized in other studies to...
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Groundwater is a vital resource to the Mississippi embayment region of the central United States. Regional and integrated assessments of water availability that link physical flow models and water quality in principal aquifer systems provide context for the long-term availability of these water resources. An innovative approach using machine learning was employed to predict groundwater pH across drinking water aquifers of the Mississippi embayment. The region includes two principal regional aquifer systems; the Mississippi River Valley alluvial (MRVA) aquifer and the Mississippi embayment aquifer system that includes several regional aquifers and confining units. Based on the distribution of groundwater use for...
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Of the approximately 6.6 million people living in the Mississippi embayment (MISE) region in the central United States, approximately 65 percent rely on groundwater for their drinking water (Dieter, Linsey, and others, 2017). Regional assessments of water quality in principal aquifer systems provide context for the long-term availability of these water resources for drinking-water supplies. To assess the current (2018) status of water quality in MISE in relation to drinking water supplies, groundwater withdrawal zones used for domestic and public supply were modeled using available groundwater well and hydrogeologic framework data. Three dimensional surfaces were modeled to map the depth zones at which groundwater...
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These datasets include wells, springs, and contours used to construct the Hot Springs Highway 270 bypass pre-construction potentiometric-surface map. During the summer of 2017, the U.S. Geological Survey and Hot Springs National Park Service collected groundwater measurements from 66 wells - 59 measurements were used to construct a potentiometric-surface map of wells screened in the Ouachita Mountains aquifer system. The pre-construction potentiometric-surface map provides an early, baseline assessment of groundwater levels and flow directions which will be compared to a later, post-construction groundwater potentiometric-surface map. In addition, comparisons to the pre-construction map will help to identify...
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Groundwater residence times and flow path lengths were simulated for two major aquifers of the Mississippi embayment region using particle tracking (Pollock, 2012; Starn and Belitz, 2018) in a regional groundwater-flow model (Haugh and others, 2020). The Mississippi embayment physiographic region includes two principal aquifer systems: the surficial aquifer system, which is dominated by the Quaternary Mississippi River Valley alluvial aquifer (MRVA), and the Mississippi embayment aquifer system, which includes deeper Tertiary aquifers and confining units. The groundwater residence time simulation focused on the MRVA and two hydrogeologic units of the Claiborne Group (CLBG) from the deeper system, including the middle...
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This dataset contains 50-ft contours for the Hot Springs shallowest unit of the Ouachita Mountains aquifer system potentiometric-surface map. The potentiometric-surface shows altitude at which the water level would have risen in tightly-cased wells and represents synoptic conditions during the summer of 2017. Contours were constructed from 59 water-level measurements measured in selected wells (locations in the well point dataset). Major streams and creeks were selected in the study area from the USGS National Hydrography Dataset (U.S. Geological Survey, 2017), and the spring point dataset with 18 spring altitudes calculated from 10-meter digital elevation model (DEM) data (U.S. Geological Survey, 2015; U.S. Geological...
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Groundwater is a vital resource in the Mississippi embayment of the central United States. An innovative approach using machine learning (ML) was employed to predict groundwater salinity—including specific conductance (SC), total dissolved solids (TDS), and chloride (Cl) concentrations—across three drinking-water aquifers of the Mississippi embayment. A ML approach was used because it accommodates a large and diverse set of explanatory variables, does not assume monotonic relations between predictors and response data, and results can be extrapolated to areas of the aquifer not sampled. These aspects of ML allowed potential drivers and sources of high salinity water that have been hypothesized in other studies to...
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Groundwater is a vital resource to the Mississippi embayment region of the central United States. Regional and integrated assessments of water availability that link physical flow models and water quality in principal aquifer systems provide context for the long-term availability of these water resources. An innovative approach using machine learning was employed to predict groundwater pH across drinking water aquifers of the Mississippi embayment. The region includes two principal regional aquifer systems; the Mississippi River Valley alluvial (MRVA) aquifer and the Mississippi embayment aquifer system that includes several regional aquifers and confining units. Based on the distribution of groundwater use for...
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This page contains (a) bulk synchrotron-based X-ray absorption spectra; (b) microbeam synchrotron-based X-ray fluorescence maps and spectra; and (c) microbeam Raman spectra (and corresponding optical images). These data were used to understand chromium, iron, and manganese valence and mineral residence in natural and synthetic mineral mixtures used in laboratory experiments designed to simulate dynamic conditions in an engineered aquifer system [see Izbicki and Groover (2018) and Miller and others (2020)].
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This child page contains: (a) qualitative compositional data for 3 elements (chromium, manganese, and iron) as determined by X-ray fluorescence spectrometry using a portable instrument (“pXRF”) mounted in a test stand in the laboratory and (b) quantitative compositional data for up to 60 elements (some not reported quantitatively) determined by chemical digestion (sodium peroxide fusion) followed by inductively-coupled plasma-optical emission or inductively-coupled plasma-mass spectrometry, and (c) quantitative total organic carbon data. The pXRF data collected after July 22, 2019 presented here is subject to secondary data review as required by the Energy and Minerals Mission Area Quality Management System (EMMA...
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The Edwards aquifer is a karst aquifer system that is a primary water source for a large part of central Texas including the city of San Antonio, Texas. These vector geospatial data represent the geographic extent of the contributing zones for the Northern, Barton Springs, and San Antonio segments of the Edwards aquifer. The contributing zone is defined as the drainage area of the Edwards Plateau that contributes surface water to the Edwards aquifer recharge zone. The recharge zone is where surface water and precipitation infiltrate into the outcrop of the rocks that compose the aquifer (see Ashworth and Hopkins, 1995, and George and others, 2011). References Ashworth, J.B., and Hopkins, Janie, 1995, Aquifers of...
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This data release contains groundwater-quality data for three parameters of interest (arsenic, manganese, and pH) and well information for sample sites for aquifers in the conterminous U.S. Water-quality data and well information were derived from a dataset compiled from three sources: the U.S. Geological Survey (USGS) National Water Information System (NWIS), the U.S. Environmental Protection Agency (USEPA) Safe Drinking Water Information System (SDWIS), and numerous agencies and organizations at the state, regional, and local level. The data compilation of the National Water Quality Program’s groundwater assessment team is an internal dataset informally referred to as the National Groundwater Aggregation (NGA)....
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Groundwater is a vital resource in the Mississippi embayment physiographic region (Mississippi embayment) of the central United States and can be limited in some areas by high concentrations of trace elements. The concentration of trace elements in groundwater is largely driven by oxidation-reduction (redox) processes. Redox processes are a group of biotically driven reactions in which energy is derived from the exchange of electrons. In groundwater, this commonly occurs through decomposition of organic matter (carbon) by microbes, which consumes dissolved oxygen (DO). Under low DO conditions, iron (Fe), manganese, and arsenic can dissolve from coatings on aquifer sediments and be released into groundwater. Therefore,...
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This dataset contains 10-foot contours of the 2013 Lower Potomac-Raritan-Magothy aquifer potentiometric surface in the Coastal Plain of New Jersey. The potentiometric-surface contours show altitudes at which water levels would have risen in tightly-cased wells and represent conditions in October 2013 through January 2014. Groundwater-level data from 92 wells cased in, and with the screened interval open to the Lower Potomac-Raritan-Magothy aquifer, were used to construct the potentiometric surface and are publicly available from the U.S. Geological Survey's National Water Information System.
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This dataset contains 10-foot contours of the 2013 Middle Potomac-Raritan-Magothy aquifer potentiometric surface in the Coastal Plain of New Jersey. The potentiometric-surface contours show altitudes at which water levels would have risen in tightly-cased wells and represent conditions in October 2013 through January 2014. Groundwater-level data from 171 wells cased in, and with the screened interval open to the Middle Potomac-Raritan-Magothy aquifer, were used to construct the potentiometric surface and are publicly available from the U.S. Geological Survey's National Water Information System.
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The groundwater-level change maps for the Sparta-Memphis aquifer are constructed as a point-to-point comparison between wells measured in both 2011 and 2013. Wells not measured in both 2011 and 2013 were not included in the change maps construction. The 2011-2013 change map contains 261 corresponding wells. Groundwater-level differences were calculated by subtracting 2011 groundwater-level measurements, in ft below land surface from the 2013 groundwater-level measurements, in feet below land surface.
map background search result map search result map Datasets of the Potentiometric Surface of Groundwater-Level Altitudes Near the Planned Highway 270 Bypass, East of Hot Springs, Arkansas, July–August 2017 Sparta-Memphis aquifer well point dataset, in Arkansas, January-June 2015 Water-level changes 2011-2013, in the Sparta-Memphis aquifer, in Arkansas Groundwater withdrawal zones for drinking water from the Mississippi River Valley alluvial aquifer and Mississippi embayment aquifers Contributing Zones of the San Antonio, Barton Springs, and Northern segments of the Edwards aquifer Simulated groundwater residence times in two principal aquifers of the Mississippi embayment physiographic region Machine-learning model predictions and groundwater-quality rasters of specific conductance, total dissolved solids, and chloride in aquifers of the Mississippi embayment Prediction grids of pH for the Mississippi River Valley Alluvial and Claiborne Aquifers Depth rasters for aquifers of the Mississippi Embayment Contour Dataset of the Potentiometric Surface of Groundwater-Level Altitudes Near the Planned Highway 270 Bypass, East of Hot Springs, Arkansas, July-August 2017 Depth rasters in aquifers of the Mississippi Embayment Machine-learning model predictions and groundwater-quality rasters of total dissolved solids in aquifers of the Mississippi Embayment Prediction grids of pH Dissolved oxygen probability rasters of groundwater in the Mississippi River Valley alluvial and Claiborne aquifers 2013 Potentiometric-surface contours of the Middle Potomac-Raritan-Magothy Aquifer, New Jersey 2013 Potentiometric-surface contours of the Lower Potomac-Raritan-Magothy Aquifer, New Jersey Arsenic, manganese, and pH groundwater quality data, selected well construction characteristics, and aquifer assignments for wells in the conterminous U.S. Machine-learning model predictions and rasters of arsenic and manganese in groundwater in the Mississippi River Valley alluvial aquifer Portable XRF, ICP-MS/OES, and Organic Carbon Bulk Chemical Data of Solids Used in USGS' Study of Hexavalent Chromium Contamination of Ground Water Near Hinkley, CA Raman and Synchrotron X-ray Data of Sold Phases Used in Chromium Sequestration and Re-oxidation Experiments with Sand and Sediment from Hinkley, CA Portable XRF, ICP-MS/OES, and Organic Carbon Bulk Chemical Data of Solids Used in USGS' Study of Hexavalent Chromium Contamination of Ground Water Near Hinkley, CA Raman and Synchrotron X-ray Data of Sold Phases Used in Chromium Sequestration and Re-oxidation Experiments with Sand and Sediment from Hinkley, CA Contour Dataset of the Potentiometric Surface of Groundwater-Level Altitudes Near the Planned Highway 270 Bypass, East of Hot Springs, Arkansas, July-August 2017 Datasets of the Potentiometric Surface of Groundwater-Level Altitudes Near the Planned Highway 270 Bypass, East of Hot Springs, Arkansas, July–August 2017 2013 Potentiometric-surface contours of the Lower Potomac-Raritan-Magothy Aquifer, New Jersey 2013 Potentiometric-surface contours of the Middle Potomac-Raritan-Magothy Aquifer, New Jersey Contributing Zones of the San Antonio, Barton Springs, and Northern segments of the Edwards aquifer Sparta-Memphis aquifer well point dataset, in Arkansas, January-June 2015 Water-level changes 2011-2013, in the Sparta-Memphis aquifer, in Arkansas Groundwater withdrawal zones for drinking water from the Mississippi River Valley alluvial aquifer and Mississippi embayment aquifers Simulated groundwater residence times in two principal aquifers of the Mississippi embayment physiographic region Machine-learning model predictions and groundwater-quality rasters of specific conductance, total dissolved solids, and chloride in aquifers of the Mississippi embayment Prediction grids of pH for the Mississippi River Valley Alluvial and Claiborne Aquifers Depth rasters for aquifers of the Mississippi Embayment Depth rasters in aquifers of the Mississippi Embayment Machine-learning model predictions and groundwater-quality rasters of total dissolved solids in aquifers of the Mississippi Embayment Prediction grids of pH Dissolved oxygen probability rasters of groundwater in the Mississippi River Valley alluvial and Claiborne aquifers Machine-learning model predictions and rasters of arsenic and manganese in groundwater in the Mississippi River Valley alluvial aquifer Arsenic, manganese, and pH groundwater quality data, selected well construction characteristics, and aquifer assignments for wells in the conterminous U.S.