Skip to main content
U.S. flag

An official website of the United States government

Ken Belitz

Ken Belitz is a Supervisory Research Hydrologist with the USGS Water Resources Mission Area.

Science and Products

link
Image shows a map of all 50 states color-coded for their potential for groundwater corrosivity

New Study Shows High Potential for Groundwater to be Corrosive in One-Half of U.S. States

A recent U.S. Geological Survey (USGS) assessment of more than 20,000 wells nationwide indicates that groundwater in 25 States and the District of Columbia has a high potential for being naturally corrosive. The States with the largest percentage of wells with potentially corrosive groundwater are located primarily in the Northeast, the Southeast, and the Northwest.
By
Ecosystems Mission Area, Environmental Health Program
link

New Study Shows High Potential for Groundwater to be Corrosive in One-Half of U.S. States

A recent U.S. Geological Survey (USGS) assessment of more than 20,000 wells nationwide indicates that groundwater in 25 States and the District of Columbia has a high potential for being naturally corrosive. The States with the largest percentage of wells with potentially corrosive groundwater are located primarily in the Northeast, the Southeast, and the Northwest.
Learn More
link
A rainbow arc over a large-volume public-supply well

Groundwater Quality Research

Every day, millions of gallons of groundwater are pumped to supply drinking water for about 140 million people, almost one-half of the Nation’s population. Learn about the quality and availability of groundwater for drinking, where and why groundwater quality is degraded, and where groundwater quality is changing.
By
Water Resources Mission Area, National Water Quality Program, Colorado Water Science Center, Dakota Water Science Center, Wyoming-Montana Water Science Center
link

Groundwater Quality Research

Every day, millions of gallons of groundwater are pumped to supply drinking water for about 140 million people, almost one-half of the Nation’s population. Learn about the quality and availability of groundwater for drinking, where and why groundwater quality is degraded, and where groundwater quality is changing.
Learn More
link
Corroded water pipe

Corrosivity

Corrosivity describes how aggressive water is at corroding pipes and fixtures. Corrosive water can cause lead and copper in pipes to leach into drinking water and can eventually cause leaks in plumbing. Surface water and groundwater, both sources of drinking water, can potentially be corrosive.
By
Water Resources Mission Area, National Water Quality Program
link

Corrosivity

Corrosivity describes how aggressive water is at corroding pipes and fixtures. Corrosive water can cause lead and copper in pipes to leach into drinking water and can eventually cause leaks in plumbing. Surface water and groundwater, both sources of drinking water, can potentially be corrosive.
Learn More
link
Large-volume public supply well

Public Supply Wells

Are you among the more than 100 million people in the U.S. who relies on a public-supply well for your drinking water? Although the quality of finished drinking water from public water systems is regulated by the EPA, long-term protection and management of the raw groundwater tapped by public-supply wells requires an understanding of the occurrence of contaminants in this invisible, vital resource...
By
Water Resources Mission Area, National Water Quality Program
link

Public Supply Wells

Are you among the more than 100 million people in the U.S. who relies on a public-supply well for your drinking water? Although the quality of finished drinking water from public water systems is regulated by the EPA, long-term protection and management of the raw groundwater tapped by public-supply wells requires an understanding of the occurrence of contaminants in this invisible, vital resource...
Learn More
link
Water supply well in the Edwards/Trinity aquifer

All about corrosivity

A U.S. Geological Survey assessment of more than 20,000 wells nationwide shows that untreated groundwater in 25 states has a high prevalence of being potentially corrosive. The states with the largest percentage of wells with potentially corrosive groundwater are located primarily in the Northeast, the Southeast, and the Northwest. These FAQs were written in conjunction with that study. In...
By
Water Resources Mission Area, National Water Quality Program
link

All about corrosivity

A U.S. Geological Survey assessment of more than 20,000 wells nationwide shows that untreated groundwater in 25 states has a high prevalence of being potentially corrosive. The states with the largest percentage of wells with potentially corrosive groundwater are located primarily in the Northeast, the Southeast, and the Northwest. These FAQs were written in conjunction with that study. In...
Learn More
Filter Total Items: 18

Data for depth of groundwater used for drinking-water supplies in the United States

This data release includes grids representing the depth and thickness of drinking-water withdrawal zones, polygons of hydrogeologic settings, an inventory of sources of well construction data, and summaries of data comparisons used to assess the depth of groundwater used for drinking-water supplies in the United States. Well construction data sources are documented in Table1_DataSources.xlsx. Data
By
Water Resources Mission Area

Data Release for Secondary Hydrogeologic Regions of the Conterminous United States (ver. 2.0, June 2022)

The U.S. Geological Survey (USGS) previously identified 62 Principal Aquifers (PAs) in the U.S., with 57 located in the conterminous states. The USGS characterized areas outside of PAs as “other rocks;” other rocks account for about 40% of the area of the conterminous states. This paper subdivides the large area identified as other rocks into Secondary Hydrogeologic Regions (SHRs). SHRs are define
By
Water Resources Mission Area, National Water Quality Program

Data for volatile organic compounds in groundwater used for public supply across the United States, 2013-19, and data for associated quality-control samples

This data release includes tables and time-series plots of results for volatile organic compounds (VOCs) analyzed in samples of groundwater used for public supply that were collected by the USGS National Water-Quality Assessment (NAWQA) Project and the California State Water Resources Control Board’s Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP) during 201
By
Water Resources Mission Area

Estimated equivalent population using groundwater for public supply domestic use in the conterminous U.S. 2010, hydrogeologic mapping units, and wells used (ver. 2.0, March 2023)

These datasets map the estimated population using public supply drinking water (both groundwater and surface water) using two methods: the census enhanced method (CEM) evenly distributes the population across populated census blocks, and the urban land-use enhanced method (ULUEM) distributes the population only to certain urban land use designations. (See the six Estimated equivalent population us
By
California 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
By
California Water Science Center

Data Release for Evaluation of Six Methods for Correcting Bias in Estimates from Ensemble Tree Machine Learning Regression Models

Ensemble-tree machine learning (ML) regression models can be prone to systematic bias: small values are overestimated and large values are underestimated. Additional bias can be introduced if the dependent variable is a transform of the original data. Six methods were evaluated for their ability to correct systematic and introduced bias: (1) empirical distribution matching (EDM); (2) regression of
By
Water Resources Mission Area

Inorganic Constituent and Ancillary Data for Evaluation of Lithium in Groundwater in the United States, 1991-2018

Lithium concentrations in untreated groundwater from 1,464 public-supply wells, 1,676 domestic-supply wells, and 1,560 monitoring wells distributed across 33 principal aquifers in the United States were evaluated for spatial variations and possible explanatory factors. For context, lithium concentrations are compared to a drinking-water only threshold (60 mg/L) and a Health-Based Screening Level (
By
Water Resources Mission Area

Datasets of Groundwater-Quality and Select Quality-Control Data from the National Water-Quality Assessment Project, January 2017 through December 2019

Groundwater-quality data were collected from 983 wells as part of the National Water-Quality Assessment Project of the U.S. Geological Survey National Water-Quality Program and are included in this report. The data were collected from six types of well networks: principal aquifer study networks, which are used to assess the quality of groundwater used for public water supply; land-use study networ
By
Water Resources Mission Area

Datasets from Groundwater-Quality and Select Quality-Control Data from the National Water-Quality Assessment Project, January through December 2016, and Previously Unpublished Data from 2013 to 2015

Groundwater-quality data were collected from 648 wells as part of the National Water-Quality Assessment Project of the U.S. Geological Survey National Water-Quality Program and are included in this report. Most of the wells (514) were sampled from January through December 2016 and 60 of them were sampled in 2013 and 74 in 2014. The data were collected from seven types of well networks: principal a
By
Central Midwest Water Science Center

National Multi Order Hydrologic Position (MOHP) Predictor Data for Groundwater and Groundwater-Quality Modeling

Multi Order Hydrologic Position (MOHP) raster datasets: Distance from Stream to Divide (DSD) and Lateral Position (LP) have been produced nationally for the 48 contiguous United States at a 30-meter resolution for stream orders 1 through 9. These data are available for testing as predictor variables for various regional and national groundwater-flow and groundwater-quality statistical models. The
By
Water Resources Mission Area

Point data for four case studies related to testing of multi-order hydrologic position

The location of a point (or pixel) within the conterminous U.S. can be assigned based on its position relative to the Nation's stream network. Two metrics are recognized: lateral position (LP) and distance from stream to divide (DSD). And given that a point can have different positions in different hydrologic orders the term multi-order hydrologic position (MOHP) is used to describe the ensemble
By
Water Resources Mission Area

Data for Assessing the Lead Solubility Potential of Untreated Groundwater of the United States

Groundwater chemistry data used for assessing the lead (Pb) solubility potential of untreated groundwater of the United States were compiled from the USGS National Water Information System (NWIS) database for groundwater sites sampled between January 1, 2000 and January 1, 2016. Two datasets were compiled: one dataset having 13,324 groundwater sites was used to assess Pb occurrence in untreated gr
By
California Water Science Center
Map of the US shaded by principal aquifer. Wells that were sampled are symbolized with circles
link
A graph showing the "Population potentially affected by groundwater contaminants." Geogenic affected much larger of a population compared to anthropogenic.
link
Filter Total Items: 203

Predicted uranium and radon concentrations in New Hampshire (USA) groundwater—Using Multi Order Hydrologic Position as predictors

Two radioactive elements, uranium (U) and radon (Rn), which are of potential concern in New Hampshire (NH) groundwater, are investigated. Exceedance probability maps are tools to highlight locations where the concentrations of undesirable substances in the groundwater may be elevated. Two forms of statistical analysis are used to create exceedance probability maps for U and Rn in NH groundwater. T
Authors
Richard B. Moore, Kenneth Belitz, Joseph D. Ayotte, Terri L. Arnold, Laura Hayes, Jennifer B. Sharpe, J. Jeffrey Starn
By
Water Resources Mission Area, New England Water Science Center, Central Midwest Water Science Center

Quality of groundwater used for public supply in the continental United States: A comprehensive assessment

The presence of contaminants in a source water can constrain its suitability for drinking. The quality of groundwater used for public supply was assessed in 25 principal aquifers (PAs) that account for 84% of groundwater pumped for public supply in the U.S. (89.6 million people on a proportional basis). Each PA was sampled across its lateral extent using an equal-area grid, typically with 60 wells

Authors
Kenneth Belitz, Miranda S. Fram, Bruce D. Lindsey, Paul Stackelberg, Laura M. Bexfield, Tyler D. Johnson, Bryant Jurgens, James A. Kingsbury, Peter B. McMahon, Neil M. Dubrovsky
By
Water Resources Mission Area, California Water Science Center, Colorado Water Science Center, New Mexico Water Science Center

Over a third of groundwater in USA public-supply aquifers is Anthropocene-age and susceptible to surface contamination

The distribution of groundwater age is useful for evaluating the susceptibility and sustainability of groundwater resources. Here, we compute the aquifer-scale cumulative distribution function to characterize the age distribution for 21 Principal Aquifers that account for ~80% of public-supply pumping in the United States. The aquifer-scale cumulative distribution function for each Principal Aquif
Authors
Bryant Jurgens, Kirsten Faulkner, Peter B. McMahon, Andrew Hunt, Gerolamo C. Casile, Megan B. Young, Kenneth Belitz
By
Water Resources Mission Area, California Water Science Center, Colorado Water Science Center

Volatile organic compounds in groundwater used for public supply across the United States: Occurrence, explanatory factors, and human-health context

This systematic assessment of occurrence for 85 volatile organic compounds (VOCs) in raw (untreated) groundwater used for public supply across the United States (U.S.), which includes 43 compounds not previously monitored by national studies, relates VOC occurrence to explanatory factors and assesses VOC detections in a human-health context. Samples were collected in 2013 through 2019 from 1537 pu
Authors
Laura M. Bexfield, Kenneth Belitz, Miranda S. Fram, Bruce D. Lindsey
By
Water Resources Mission Area, California Water Science Center, New Mexico Water Science Center

Mapped predictions of manganese and arsenic in an alluvial aquifer using boosted regression trees

Manganese (Mn) concentrations and the probability of arsenic (As) exceeding the drinking-water standard of 10 μg/L were predicted in the Mississippi River Valley alluvial aquifer (MRVA) using boosted regression trees (BRT). BRT, a type of ensemble-tree machine-learning model, were created using predictor variables that affect Mn and As distribution in groundwater. These variables included iron (Fe
Authors
Katherine J. Knierim, James A. Kingsbury, Kenneth Belitz, Paul Stackelberg, Burke J. Minsley, James Robert Rigby
By
Water Resources Mission Area, New England Water Science Center, Lower Mississippi-Gulf Water Science Center, Geology, Geophysics, and Geochemistry Science Center

Relation between road-salt application and increasing radium concentrations in a low-pH aquifer, southern New Jersey

The Kirkwood–Cohansey aquifer in southern New Jersey is an important source of drinking-water supplies, but the availability of the resource is limited in some areas by high concentrations of radium, a potential carcinogen at elevated concentrations. Radium (226Ra plus 228Ra) concentrations from a network of 25 drinking-water wells showed a statistically significant increase over a decadal time sc
Authors
Bruce D. Lindsey, Charles A. Cravotta, Zoltan Szabo, Kenneth Belitz, Paul Stackelberg
By
Water Resources Mission Area, New Jersey Water Science Center, Pennsylvania Water Science Center

Depth of groundwater used for drinking-water supplies in the United States

Groundwater supplies 35 percent of drinking water in the United States. Mapping the quantity and quality of groundwater at the depths used for potable supplies requires an understanding of locational variation in the characteristics of drinking-water wells (depth and open interval). Typical depths of domestic- and public-drinking-water supply wells vary by and within aquifer across the United Stat
Authors
James R. Degnan, Leon J. Kauffman, Melinda L. Erickson, Kenneth Belitz, Paul E. Stackelberg
By
Water Resources Mission Area, New England Water Science Center

Factors affecting uncertainty of public supply, self-supplied domestic, irrigation, and thermoelectric water-use data, 1985–2015—Evaluation of information sources, estimation methods, and data variability

The U.S. Geological Survey (USGS) Water-Use Program is responsible for compiling and disseminating the Nation's water-use data. Working in cooperation with local, State, and Federal agencies, the USGS has collected and published national water-use estimates every 5 years, beginning in 1950. These water-use data may vary because of actual changes in water use, because of changes in estimation metho
Authors
Carol L. Luukkonen, Kenneth Belitz, Samantha L. Sullivan, Pierre Sargent
By
Water Resources Mission Area, Upper Midwest Environmental Sciences Center, New Jersey Water Science Center, Upper Midwest Water Science Center

Machine learning predictions of nitrate in groundwater used for drinking supply in the conterminous United States

Groundwater is an important source of drinking water supplies in the conterminous United State (CONUS), and presence of high nitrate concentrations may limit usability of groundwater in some areas because of the potential negative health effects. Prediction of locations of high nitrate groundwater is needed to focus mitigation and relief efforts. A three-dimensional extreme gradient boosting (XGB)
Authors
Katherine Marie Ransom, Bernard T. Nolan, Paul Stackelberg, Kenneth Belitz, Miranda S. Fram
By
Water Resources Mission Area, California Water Science Center

Predicting regional fluoride concentrations at public and domestic supply depths in basin-fill aquifers of the western United States using a random forest model

A random forest regression (RFR) model was applied to over 12,000 wells with measured fluoride (F) concentrations in untreated groundwater to predict F concentrations at depths used for domestic and public supply in basin-fill aquifers of the western United States. The model relied on twenty-two regional-scale environmental and surficial predictor variables selected to represent factors known to c
Authors
Celia Z Rosecrans, Kenneth Belitz, Katherine Marie Ransom, Paul E. Stackelberg, Peter B. McMahon
By
Water Resources Mission Area, California Water Science Center, Colorado Water Science Center, New England Water Science Center, New York Water Science Center

Populations using public-supply groundwater in the conterminous U.S. 2010; Identifying the wells, hydrogeologic regions, and hydrogeologic mapping units

Most Americans receive their drinking water from publicly supplied sources, a large portion of it from groundwater. Mapping these populations consistently and at a high resolution is important for understanding where the resource is used and needs to be protected. The results show that 269 million people are supplied by public supply, 107 million are supplied by groundwater and 162 million are sup
Authors
Tyler D. Johnson, Kenneth Belitz, Leon J. Kauffman, Elise Watson, John T. Wilson
By
Water Resources Mission Area, California Water Science Center, Ohio-Kentucky-Indiana Water Science Center, New England Water Science Center, New Jersey Water Science Center

Groundwater-quality and select quality-control data from the National Water-Quality Assessment Project, January 2017 through December 2019

Groundwater-quality environmental data were collected from 983 wells as part of the National Water-Quality Assessment Project of the U.S. Geological Survey National Water Quality Program and are included in this report. The data were collected from six types of well networks: principal aquifer study networks, which are used to assess the quality of groundwater used for public water supply; land-us
Authors
James A. Kingsbury, Laura M. Bexfield, Terri Arnold, MaryLynn Musgrove, Melinda L. Erickson, James R. Degnan, Anthony J. Tesoriero, Bruce D. Lindsey, Kenneth Belitz
By
Water Resources Mission Area, National Water Quality Program, Central Midwest Water Science Center, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center, Oregon Water Science Center, Oklahoma-Texas Water Science Center, Lower Mississippi-Gulf Water Science Center
link

Naturally occurring constituents are more prevalent at elevated concentrations in U.S. groundwater compared to human-caused constituents

A new report has found that at a national scale, naturally occurring constituents were more prevalent at elevated concentrations in groundwater than...

Read Article

Science and Products