Tyler Johnson (Former Employee)
Science and Products
Filter Total Items: 22
Potential Explanatory Variables for Groundwater Quality in California Potential Explanatory Variables for Groundwater Quality in California
This data release codifies and attributes values for potential explanatory factors to groundwater well locations and to groundwater basins in California. The groundwater sites are 282,000 wells that have water-quality data and are listed in the California State Water Resources Control Boards' Groundwater Ambient Monitoring and Assessment Program Groundwater Information System (GAMA GIS)...
Data from Decadal Change in Groundwater Quality Web Site, 1988-2022 Data from Decadal Change in Groundwater Quality Web Site, 1988-2022
Evaluating Decadal Changes in Groundwater Quality: Groundwater-quality data were collected from 5,000 wells between 1988-2001 (first decadal sampling event) by the National Water-Quality Assessment Project. Samples are collected in groups of 20-30 wells with similar characteristics called networks. About 1,500 of these wells in 67 networks were sampled again approximately 10 years later...
Data from Decadal Change in Groundwater Quality Web Site, 1988-2021 Data from Decadal Change in Groundwater Quality Web Site, 1988-2021
Evaluating Decadal Changes in Groundwater Quality: Groundwater-quality data were collected from 5,000 wells between 1988-2001 (first decadal sampling event) by the National Water-Quality Assessment Project. Samples are collected in groups of 20-30 wells with similar characteristics called networks. About 1,500 of these wells in 67 networks were sampled again approximately 10 years later...
Data Release for Secondary Hydrogeologic Regions of the Conterminous United States (ver. 2.0, June 2022) 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...
Groundwater-quality data in the Coachella Valley Domestic Supply Aquifer Study Unit, 2020: Results from the California GAMA Priority Basin Project Groundwater-quality data in the Coachella Valley Domestic Supply Aquifer Study Unit, 2020: Results from the California GAMA Priority Basin Project
The U.S. Geological Survey collected groundwater samples from 38 wells used for domestic and small system drinking water supply in the Coachella Valley of California in 2020. The wells were sampled for the Coachella Valley Basin (CODA) Domestic Aquifer Study Unit of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority...
Groundwater-quality data in the Modesto-Turlock-Merced Domestic-Supply Aquifer Study Unit, 2020-2021: Results from the California GAMA Priority Basin Project Groundwater-quality data in the Modesto-Turlock-Merced Domestic-Supply Aquifer Study Unit, 2020-2021: Results from the California GAMA Priority Basin Project
The U.S. Geological Survey collected groundwater samples from 71 wells used for domestic and small system drinking water supplies in Stanislaus and Merced counties of California during 2020-2021. The wells were sampled for the Modesto-Turlock-Merced Domestic-Supply Aquifer Study Unit of the State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program...
Filter Total Items: 27
Predicting redox conditions in groundwater at a national scale using random forest classification Predicting redox conditions in groundwater at a national scale using random forest classification
Redox conditions in groundwater may markedly affect the fate and transport of nutrients, volatile organic compounds, and trace metals, with significant implications for human health. While many local assessments of redox conditions have been made, the spatial variability of redox reaction rates makes the determination of redox conditions at regional or national scales problematic. In...
Authors
Anthony Tesoriero, Susan Wherry, Danielle Dupuy, Tyler D. Johnson
Quality of groundwater used for public supply in the continental United States: A comprehensive assessment 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...
Authors
Kenneth Belitz, Miranda Fram, Bruce Lindsey, Paul Stackelberg, Laura Bexfield, Tyler D. Johnson, Bryant Jurgens, James Kingsbury, Peter McMahon, Neil Dubrovsky
Perfluoroalkyl and polyfluoroalkyl substances in groundwater used as a source of drinking water in the eastern United States Perfluoroalkyl and polyfluoroalkyl substances in groundwater used as a source of drinking water in the eastern United States
In 2019, 254 samples were collected from five aquifer systems to evaluate per- and polyfluoroalkyl substance (PFAS) occurrence in groundwater used as a source of drinking water in the eastern United States. The samples were analyzed for 24 PFAS, major ions, nutrients, trace elements, dissolved organic carbon (DOC), volatile organic compounds (VOCs), pharmaceuticals, and tritium. Fourteen...
Authors
Peter McMahon, Andrea Tokranov, Laura Bexfield, Bruce Lindsey, Tyler D. Johnson, Melissa Lombard, Elise Watson
Populations using public-supply groundwater in the conterminous U.S. 2010; Identifying the wells, hydrogeologic regions, and hydrogeologic mapping units 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...
Authors
Tyler D. Johnson, Kenneth Belitz, Leon Kauffman, Elise Watson, John Wilson
Geochemistry and age of groundwater in the Williston Basin, USA: Assessing potential effects of shale-oil production on groundwater quality Geochemistry and age of groundwater in the Williston Basin, USA: Assessing potential effects of shale-oil production on groundwater quality
Thirty water wells were sampled in 2018 to understand the geochemistry and age of groundwater in the Williston Basin and assess potential effects of shale-oil production from the Three Forks-Bakken petroleum system (TBPS) on groundwater quality. Two geochemical groups are identified using hierarchical cluster analysis. Group 1 represents the younger (median 4He = 21.49 × 10−8 cm3 STP/g)...
Authors
Peter McMahon, Joel Galloway, Andrew G. Hunt, Kenneth Belitz, Bryant Jurgens, Tyler D. Johnson
Fluoride occurrence in United States groundwater Fluoride occurrence in United States groundwater
Data from 38,105 wells were used to characterize fluoride (F) occurrence in untreated United States (U.S.) groundwater. For domestic wells (n = 11,032), water from which is generally not purposely fluoridated or monitored for quality, 10.9% of the samples have F concentrations >0.7 mg/L (U.S. Public Health Service recommended optimal F concentration in drinking water for preventing tooth...
Authors
Peter McMahon, Craig J. Brown, Tyler D. Johnson, Kenneth Belitz, Bruce Lindsey
Science and Products
Filter Total Items: 22
Potential Explanatory Variables for Groundwater Quality in California Potential Explanatory Variables for Groundwater Quality in California
This data release codifies and attributes values for potential explanatory factors to groundwater well locations and to groundwater basins in California. The groundwater sites are 282,000 wells that have water-quality data and are listed in the California State Water Resources Control Boards' Groundwater Ambient Monitoring and Assessment Program Groundwater Information System (GAMA GIS)...
Data from Decadal Change in Groundwater Quality Web Site, 1988-2022 Data from Decadal Change in Groundwater Quality Web Site, 1988-2022
Evaluating Decadal Changes in Groundwater Quality: Groundwater-quality data were collected from 5,000 wells between 1988-2001 (first decadal sampling event) by the National Water-Quality Assessment Project. Samples are collected in groups of 20-30 wells with similar characteristics called networks. About 1,500 of these wells in 67 networks were sampled again approximately 10 years later...
Data from Decadal Change in Groundwater Quality Web Site, 1988-2021 Data from Decadal Change in Groundwater Quality Web Site, 1988-2021
Evaluating Decadal Changes in Groundwater Quality: Groundwater-quality data were collected from 5,000 wells between 1988-2001 (first decadal sampling event) by the National Water-Quality Assessment Project. Samples are collected in groups of 20-30 wells with similar characteristics called networks. About 1,500 of these wells in 67 networks were sampled again approximately 10 years later...
Data Release for Secondary Hydrogeologic Regions of the Conterminous United States (ver. 2.0, June 2022) 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...
Groundwater-quality data in the Coachella Valley Domestic Supply Aquifer Study Unit, 2020: Results from the California GAMA Priority Basin Project Groundwater-quality data in the Coachella Valley Domestic Supply Aquifer Study Unit, 2020: Results from the California GAMA Priority Basin Project
The U.S. Geological Survey collected groundwater samples from 38 wells used for domestic and small system drinking water supply in the Coachella Valley of California in 2020. The wells were sampled for the Coachella Valley Basin (CODA) Domestic Aquifer Study Unit of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority...
Groundwater-quality data in the Modesto-Turlock-Merced Domestic-Supply Aquifer Study Unit, 2020-2021: Results from the California GAMA Priority Basin Project Groundwater-quality data in the Modesto-Turlock-Merced Domestic-Supply Aquifer Study Unit, 2020-2021: Results from the California GAMA Priority Basin Project
The U.S. Geological Survey collected groundwater samples from 71 wells used for domestic and small system drinking water supplies in Stanislaus and Merced counties of California during 2020-2021. The wells were sampled for the Modesto-Turlock-Merced Domestic-Supply Aquifer Study Unit of the State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program...
Filter Total Items: 27
Predicting redox conditions in groundwater at a national scale using random forest classification Predicting redox conditions in groundwater at a national scale using random forest classification
Redox conditions in groundwater may markedly affect the fate and transport of nutrients, volatile organic compounds, and trace metals, with significant implications for human health. While many local assessments of redox conditions have been made, the spatial variability of redox reaction rates makes the determination of redox conditions at regional or national scales problematic. In...
Authors
Anthony Tesoriero, Susan Wherry, Danielle Dupuy, Tyler D. Johnson
Quality of groundwater used for public supply in the continental United States: A comprehensive assessment 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...
Authors
Kenneth Belitz, Miranda Fram, Bruce Lindsey, Paul Stackelberg, Laura Bexfield, Tyler D. Johnson, Bryant Jurgens, James Kingsbury, Peter McMahon, Neil Dubrovsky
Perfluoroalkyl and polyfluoroalkyl substances in groundwater used as a source of drinking water in the eastern United States Perfluoroalkyl and polyfluoroalkyl substances in groundwater used as a source of drinking water in the eastern United States
In 2019, 254 samples were collected from five aquifer systems to evaluate per- and polyfluoroalkyl substance (PFAS) occurrence in groundwater used as a source of drinking water in the eastern United States. The samples were analyzed for 24 PFAS, major ions, nutrients, trace elements, dissolved organic carbon (DOC), volatile organic compounds (VOCs), pharmaceuticals, and tritium. Fourteen...
Authors
Peter McMahon, Andrea Tokranov, Laura Bexfield, Bruce Lindsey, Tyler D. Johnson, Melissa Lombard, Elise Watson
Populations using public-supply groundwater in the conterminous U.S. 2010; Identifying the wells, hydrogeologic regions, and hydrogeologic mapping units 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...
Authors
Tyler D. Johnson, Kenneth Belitz, Leon Kauffman, Elise Watson, John Wilson
Geochemistry and age of groundwater in the Williston Basin, USA: Assessing potential effects of shale-oil production on groundwater quality Geochemistry and age of groundwater in the Williston Basin, USA: Assessing potential effects of shale-oil production on groundwater quality
Thirty water wells were sampled in 2018 to understand the geochemistry and age of groundwater in the Williston Basin and assess potential effects of shale-oil production from the Three Forks-Bakken petroleum system (TBPS) on groundwater quality. Two geochemical groups are identified using hierarchical cluster analysis. Group 1 represents the younger (median 4He = 21.49 × 10−8 cm3 STP/g)...
Authors
Peter McMahon, Joel Galloway, Andrew G. Hunt, Kenneth Belitz, Bryant Jurgens, Tyler D. Johnson
Fluoride occurrence in United States groundwater Fluoride occurrence in United States groundwater
Data from 38,105 wells were used to characterize fluoride (F) occurrence in untreated United States (U.S.) groundwater. For domestic wells (n = 11,032), water from which is generally not purposely fluoridated or monitored for quality, 10.9% of the samples have F concentrations >0.7 mg/L (U.S. Public Health Service recommended optimal F concentration in drinking water for preventing tooth...
Authors
Peter McMahon, Craig J. Brown, Tyler D. Johnson, Kenneth Belitz, Bruce Lindsey