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James Reddy

Intro

Bachelor of Science (Geography) Pennyslvania State University, 1984

Image Analyst, Bionetics Corporation, Warrenton, VA, 1985 - 1996

Cartographic Technician, Geologic Division, US Geological Survey, Reston, VA, 1997 - 2002

Physical Scientist, Water Resources Division, US Geological Survey, Ithaca, NY, 2003 - Present



 

Science and Products

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map of New York state with colored areas for aquifers

Statewide Assessment of New York’s Karst Aquifers With an Inventory of Closed-Depression and Focused-Recharge Features

Background: The New York State Departments of Environmental Conservation (NYS DEC) and Health (NYS DOH) are concerned about groundwater contamination in the carbonate-bedrock aquifers in New York, especially relating to the unintended introduction of volatile organic compounds (VOCs) and liquid manure to these aquifers. These carbonate rocks form extensive aquifers that transmit, and can yield, wa
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New York Water Science Center
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Statewide Assessment of New York’s Karst Aquifers With an Inventory of Closed-Depression and Focused-Recharge Features

Background: The New York State Departments of Environmental Conservation (NYS DEC) and Health (NYS DOH) are concerned about groundwater contamination in the carbonate-bedrock aquifers in New York, especially relating to the unintended introduction of volatile organic compounds (VOCs) and liquid manure to these aquifers. These carbonate rocks form extensive aquifers that transmit, and can yield, wa
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multicolored illustration of layers of geologic units in western NY

Hydrogeologic Recharge Settings of the Carbonate-Bedrock Aquifers in Livingston and Monroe Counties, Western New York

Background: A sequence of gently dipping carbonate bedrock - the Bertie Formation, Akron Dolostone, and Onondaga Limestone crop out along a 2- to5-mile wide band in western and central New York. These bedrock units trend east-west for 250 miles across the State and form extensive carbonate-bedrock aquifers which transmit and yield water from solution-enlarged fractures, bedding planes, and other
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New York Water Science Center
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Hydrogeologic Recharge Settings of the Carbonate-Bedrock Aquifers in Livingston and Monroe Counties, Western New York

Background: A sequence of gently dipping carbonate bedrock - the Bertie Formation, Akron Dolostone, and Onondaga Limestone crop out along a 2- to5-mile wide band in western and central New York. These bedrock units trend east-west for 250 miles across the State and form extensive carbonate-bedrock aquifers which transmit and yield water from solution-enlarged fractures, bedding planes, and other
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map of New York counties with study area in black

Hydrogeologic Recharge Settings of the Carbonate-Bedrock Aquifer in Genesee County, Western New York

Problem - The New York State Departments of Environmental Conservation (NYSDEC) and Health (NYSDOH) are concerned about Problem - The New York State Departments of Environmental Conservation (NYSDEC) and Health (NYSDOH) are concerned about ground-water contamination in the carbonate-bedrock aquifers, especially relating to the inadvertent introduction of volatile organic compounds (VOCs) and m
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New York Water Science Center
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Hydrogeologic Recharge Settings of the Carbonate-Bedrock Aquifer in Genesee County, Western New York

Problem - The New York State Departments of Environmental Conservation (NYSDEC) and Health (NYSDOH) are concerned about Problem - The New York State Departments of Environmental Conservation (NYSDEC) and Health (NYSDOH) are concerned about ground-water contamination in the carbonate-bedrock aquifers, especially relating to the inadvertent introduction of volatile organic compounds (VOCs) and m
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calm water with rocks and green leafed trees on banks

Hydrogeology and Surface/Groundwater Interactions in the Meads Creek Valley, Schuyler and Steuben Counties, New York

Problem - The interaction between ground water and surface water within the Meads Creek watershed is not well understood, and the need for understanding the interaction has increased in recent years because of widespread concerns related to water supply, ground- and surface-water contamination, loss of wetlands due to development; and other changes in the watershed. In addition, flooding in th
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New York Water Science Center
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Hydrogeology and Surface/Groundwater Interactions in the Meads Creek Valley, Schuyler and Steuben Counties, New York

Problem - The interaction between ground water and surface water within the Meads Creek watershed is not well understood, and the need for understanding the interaction has increased in recent years because of widespread concerns related to water supply, ground- and surface-water contamination, loss of wetlands due to development; and other changes in the watershed. In addition, flooding in th
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Hydrogen and oxygen stable isotope mass balance evaluation of the National Water Model (v2.1) streamflow, runoff and groundwater flows

This data release contains the results of an isotopic mass balance approach to provide an estimate of the long-term average isotope ratios of NWM streamflow for the summer season (JJA) between 2000 and 2019 in the Western United States. The NWM-estimated long-term average isotope ratios are compared directly to 6426 stream stable isotope observations in 995 unique catchments. Quantified similariti
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Utah Water Science Center

Data for Machine Learning Predictions of Nitrate in Groundwater Used for Drinking Supply in the Conterminous United States

A three-dimensional extreme gradient boosting (XGB) machine learning model was developed to predict the distribution of nitrate in groundwater across the conterminous United States (CONUS). Nitrate was predicted at a 1-square-kilometer (km) resolution for two drinking water zones, each of variable depth, one for domestic supply and one for public supply. The model used measured nitrate concentrati
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California Water Science Center

Groundwater data, predictor variables, and rasters used for predicting redox conditions in the glacial aquifer, northern continental United States

This data release contains input data used in model development and TIF raster files used to predict the probability of low dissolved oxygen (DO) and high dissolved iron (Fe) in groundwater within the glacial aquifer system in the northern continental United States. Input data include measured DO and Fe concentrations at groundwater wells, and associated predictor variable data. The probability of
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Water Resources Mission Area

Data for machine learning predictions of pH in the glacial aquifer system, northern USA

A boosted regression tree (BRT) model was developed to predict pH conditions in three-dimensions throughout the glacial aquifer system (GLAC) of the contiguous United States using pH measurements in samples from 18,258 wells and predictor variables that represent aspects of the hydrogeologic setting. Model results indicate that the carbonate content of soils and aquifer materials strongly controls
By
Water Resources Mission Area

Data for Three-dimensional distribution of groundwater residence time metrics in the glaciated United States using metamodels trained on general numerical simulation models

Residence time distribution (RTD) is a critically important characteristic of groundwater flow systems; however, it cannot be measured directly. RTD can be inferred from tracer data with analytical models (few parameters) or with numerical models (many parameters). The second approach permits more variation in system properties but is used less frequently than the first because large-scale numeric
By
Water Resources Mission Area

Data for statewide assessment of New York's karst aquifers with an inventory of closed-depression and focused-recharge features

The New York State Departments of Environmental Conservation and Health are concerned about groundwater contamination in the carbonate-bedrock aquifers with the potential to host karst features throughout New York State, especially relating to the unintended introduction of chemical or agricultural contamination into these aquifers. USGS Scientific Investigations Report, SIR 2020-5030 (Kappel and
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New York Water Science Center

Data for Elevated Manganese Concentrations in United States Groundwater, Role of Land Surface-Soil-Aquifer Connections

Chemical data from 43,334 wells were used to examine the role of land surface-soil-aquifer connections in producing elevated manganese concentrations (>300 microgram/L) in United States (U.S.) groundwater. Elevated manganese and dissolved organic carbon (DOC) concentrations were associated with shallow water tables and organic-carbon rich soils, suggesting soil-derived DOC supported manganese redu
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Water Resources Mission Area, National Water Quality Program

Databases used to develop a hydrogeologic framework for Quaternary sediments in the glaciated conterminous United States

This dataset is a compilation of six databases described in Haj, A.E., Soller, D.R., Reddy, J.E., Kauffman, L.J., Yager, R.M., and Buchwald, C.A., 2018, Hydrogeologic framework for characterization and occurrence of confined and unconfined aquifers in quaternary sediments in the glaciated conterminous United States - A digital map compilation and database: U.S. Geological Survey Data Series 1090,
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Central Midwest Water Science Center

Data Release for Metamodeling and Mapping of Nitrate Flux in the Unsaturated Zone and Groundwater, Wisconsin, USA

Widespread nitrate contamination of groundwater in agricultural areas poses a major challenge to sustainable water resources. Efficient analysis of nitrate fluxes across large regions also remains difficult. This study introduces a method of characterizing nitrate transport processes continuously across regional unsaturated zones and groundwater based on surrogate, machine-learning metamodels of a
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Water Resources Mission Area, National Water Quality Program

Hydrogeologic and geospatial data for the assessment of focused recharge to the carbonate-rock Aquifer in Genesee County, New York

Existing hydrogeologic and geospatial data useful for the assessment of focused recharge to the carbonate-rock aquifer in the central part of Genesee County, NY, were compiled from numerous local, State, and Federal agency sources. Data sources utilized in this pilot study include available geospatial datasets from Federal and State agencies, interviews with local highway departments and the Genes
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Water Resources Mission Area, New York Water Science Center

Geologic Map of the Frederick 30' x 60' Quadrangle, Maryland, Virginia, and West Virginia

The Frederick 30? ? 60? quadrangle lies within the Potomac River watershed of the Chesapeake Bay drainage basin. The map area covers parts of Montgomery, Howard, Carroll, Frederick, and Washington Counties in Maryland; Loudoun, Clarke, and Fairfax Counties in Virginia; and Jefferson and Berkeley Counties in West Virginia. Many geologic features (such as faults and folds) are named for geographic f
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Groundwater quality in the Mohawk and western New York River Basins, New York, 2016

Water samples were collected from July through December 2016 from 9 production wells and 13 domestic wells in the Mohawk River Basin, and from 17 production wells and 17 domestic wells in the western New York River Basins. The samples were collected and processed by using standard U.S. Geological Survey methods and were analyzed for 320 physicochemical properties and constituents, including dissol
Authors
Devin L. Gaige, Tia-Marie Scott, James E. Reddy, Meaghan R. Keefe
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Water Resources Mission Area, New York Water Science Center

Machine-learning predictions of high arsenic and high manganese at drinking water depths of the glacial aquifer system, northern continental United States

Globally, over 200 million people are chronically exposed to arsenic (As) and/or manganese (Mn) from drinking water. We used machine-learning (ML) boosted regression tree (BRT) models to predict high As (>10 μg/L) and Mn (>300 μg/L) in groundwater from the glacial aquifer system (GLAC), which spans 25 states in the northern United States and provides drinking water to 30 million people. Our BRT mo
Authors
Melinda L. Erickson, Sarah M. Elliott, Craig J. Brown, Paul Stackelberg, Katherine Marie Ransom, James E. Reddy, Charles A. Cravotta
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Water Resources Mission Area, California Water Science Center, New England Water Science Center, New York Water Science Center, Pennsylvania Water Science Center, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center

Machine learning predicted redox conditions in the glacial aquifer system, northern continental United States

Groundwater supplies 50% of drinking water worldwide and 30% in the United States. Geogenic and anthropogenic contaminants can, however, compromise water quality, thus limiting groundwater availability. Reduction/oxidation (redox) processes and redox conditions affect groundwater quality by influencing the mobility and transport of common geogenic and anthropogenic contaminants. In the glacial aqu
Authors
Melinda L. Erickson, Sarah M. Elliott, Craig J. Brown, Paul Stackelberg, Katherine Marie Ransom, James E. Reddy
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Water Resources Mission Area, California Water Science Center, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center, New York Water Science Center

Three-dimensional distribution of residence time metrics in the glaciated United States using metamodels trained on general numerical models

Residence time distribution (RTD) is a critically important characteristic of groundwater flow systems; however, it cannot be measured directly. RTD can be inferred from tracer data with analytical models (few parameters) or with numerical models (many parameters). The second approach permits more variation in system properties but is used less frequently than the first because large‐scale numeric
Authors
J. Jeffrey Starn, Leon J. Kauffman, Carl S. Carlson, James E. Reddy, Michael N. Fienen
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Water Resources Mission Area, National Water Quality Program

Methods of data collection and analysis for an assessment of karst aquifer systems between Albany and Buffalo, New York

The U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, catalogued aquifers and closed depressions in a karst-prone area between Albany and Buffalo, New York to provide resource managers information to more efficiently manage and protect groundwater resources. The New York State Department of Environmental Conservation has been working with the
Authors
Bradley A. Sporleder, Benjamin N. Fisher, Douglas S. Keto, William M. Kappel, James E. Reddy, Laura M. DeMott
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Water Resources Mission Area, New York Water Science Center

Machine learning predictions of pH in the Glacial Aquifer System, Northern USA

A boosted regression tree model was developed to predict pH conditions in three dimensions throughout the glacial aquifer system of the contiguous United States using pH measurements in samples from 18,386 wells and predictor variables that represent aspects of the hydrogeologic setting. Model results indicate that the carbonate content of soils and aquifer materials strongly controls pH and, when
Authors
Paul Stackelberg, Kenneth Belitz, Craig J. Brown, Melinda L. Erickson, Sarah M. Elliott, Leon J. Kauffman, Katherine Marie Ransom, James E. Reddy
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Water Resources Mission Area

Statewide assessment of karst aquifers in New York with an inventory of closed-depression and focused-recharge features

Karst is a landscape formed from the dissolution of soluble rock or rock containing minerals that are easily dissolved from within the rock. The landscape is characterized by sinkholes, caves, losing streams, springs, and underground drainage systems, which rapidly move water through the karst. The two forms of karst in New York State include carbonate karst, which forms in carbonate rock (limesto
Authors
William M. Kappel, James E. Reddy, Jonathan Casey Root
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Water Resources Mission Area, New York Water Science Center

Groundwater quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

The U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, collected groundwater samples from 5 production wells and 5 domestic wells in the Delaware River Basin, 8 production wells and 7 domestic wells in the Genesee River Basin, and 1 municipal well, 7 production wells, and 13 domestic wells in the St. Lawrence River Basin in New York. All sample
Authors
Tia-Marie Scott, Elizabeth A. Nystrom, James E. Reddy
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Water Resources Mission Area, New York Water Science Center

Elevated manganese concentrations in United States groundwater, role of land surface–soil–aquifer connections

Chemical data from 43 334 wells were used to examine the role of land surface–soil–aquifer connections in producing elevated manganese concentrations (>300 μg/L) in United States (U.S.) groundwater. Elevated concentrations of manganese and dissolved organic carbon (DOC) in groundwater are associated with shallow, anoxic water tables and soils enriched in organic carbon, suggesting soil-derived DOC
Authors
Peter B. McMahon, Kenneth Belitz, James E. Reddy, Tyler D. Johnson
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Water Resources Mission Area

Hydrogeologic framework for characterization and occurrence of confined and unconfined aquifers in quaternary sediments in the glaciated conterminous United States—A digital map compilation and database

The U.S. Geological Survey has created a hydrogeologic framework for Quaternary sediments in glaciated areas of the conterminous United States that categorizes, maps, and characterizes the glacial sediments at and beneath the land surface. The hydrogeologic framework divides the glaciated United States into 17 distinct hydrogeologic terranes using a geologic approach based on previous mapping, and
Authors
Adel E. Haj, David R. Soller, James E. Reddy, Leon J. Kauffman, Richard M. Yager, Cheryl A. Buchwald
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Water Resources Mission Area

Characterization and occurrence of confined and unconfined aquifers in Quaternary sediments in the glaciated conterminous United States

The glacial aquifer system, which is a collection of aquifers within Quaternary sediments in the glaciated conterminous United States, is a principal aquifer that supplies groundwater that serves about 42 million people and accounts for about 5 percent of the Nation’s drinking water. This aquifer system (the area of maximum glacial advance) underlies parts of 25 States and covers 1.87×106 square k
Authors
Richard M. Yager, Leon J. Kauffman, David R. Soller, Adel E. Haj, Paul M. Heisig, Cheryl A. Buchwald, Stephen, M. Westenbroek, James E. Reddy
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Water Resources Mission Area

Metamodeling and mapping of nitrate flux in the unsaturated zone and groundwater, Wisconsin, USA

Nitrate contamination of groundwater in agricultural areas poses a major challenge to the sustainability of water resources. Aquifer vulnerability models are useful tools that can help resource managers identify areas of concern, but quantifying nitrogen (N) inputs in such models is challenging, especially at large spatial scales. We sought to improve regional nitrate (NO3−) input functions by cha
Authors
Bernard T. Nolan, Christopher T. Green, Paul F. Juckem, Lixia Liao, James E. Reddy
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Water Resources Mission Area

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