Leon Kauffman
Leon Kauffman is a scientist working remotely with the New Jersey Water Science Center Integrated Hydrology Investigation Team
Science and Products
Filter Total Items: 25
Data for depth of groundwater used for drinking-water supplies in the United States (ver. 2.0, January 2026) Data for depth of groundwater used for drinking-water supplies in the United States (ver. 2.0, January 2026)
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...
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) 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...
Data for Three-dimensional distribution of groundwater residence time metrics in the glaciated United States using metamodels trained on general numerical simulation models 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...
Data used to evaluate drinking water quality in the glacial aquifer system, northern USA Data used to evaluate drinking water quality in the glacial aquifer system, northern USA
This data release contains groundwater-quality data and well information for the glacial aquifer system in the northern USA. 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; USGS, 1998, 2002), the U.S. Environmental Protection Agency (USEPA) Safe Drinking Water...
Data and Scripts for Metamodeling for Groundwater Age Forecasting in the Lake Michigan Basin Data and Scripts for Metamodeling for Groundwater Age Forecasting in the Lake Michigan Basin
Groundwater age is an important indicator of groundwater susceptibility to anthropogenic contamination and a key input to statistical models for forecasting water quality. Numerical models can provide estimates of groundwater age, enabling interpretation of measured age tracers. However, to extend to national-scale groundwater systems where numerical models are not routinely available, a...
Digital products from a hydrogeologic framework for Quaternary sediments within the glaciated conterminous United States Digital products from a hydrogeologic framework for Quaternary sediments within the glaciated conterminous United States
This data release is a compilation of the digital products from a hydrogeologic framework of the glaciated conterminous United States that were constructed to portray sediment and aquifer characteristics within this area. These digital products are described in Yager, R.M., Kauffman, L.J., Soller, D.R., Haj, A.E., Heisig, P.M., Buchwald, C.A., Westenbroek, S.M., and Reddy, J.E., 2018
Filter Total Items: 41
On modeling weak sinks in MODPATH On modeling weak sinks in MODPATH
Regional groundwater flow systems often contain both strong sinks and weak sinks. A strong sink extracts water from the entire aquifer depth, while a weak sink lets some water pass underneath or over the actual sink. The numerical groundwater flow model MODFLOW may allow a sink cell to act as a strong or weak sink, hence extracting all water that enters the cell or allowing some of that...
Authors
Daniel B. Abrams, Henk Haitjema, Leon J. Kauffman
Modeling the potential impact of seasonal and inactive multi-aquifer wells on contaminant movement to public water-supply wells Modeling the potential impact of seasonal and inactive multi-aquifer wells on contaminant movement to public water-supply wells
Wells screened across multiple aquifers can provide pathways for the movement of surprisingly large volumes of groundwater to confined aquifers used for public water supply (PWS). Using a simple numerical model, we examine the impact of several pumping scenarios on leakage from an unconfined aquifer to a confined aquifer and conclude that a single inactive multi-aquifer well can...
Authors
R.L. Johnson, B.R. Clark, M.K. Landon, L. J. Kauffman, S. M. Eberts
Simulations of groundwater flow and particle-tracking analysis in the zone of contribution to a public-supply well in San Antonio, Texas Simulations of groundwater flow and particle-tracking analysis in the zone of contribution to a public-supply well in San Antonio, Texas
In 2006, a public-supply well in San Antonio, Texas, was selected for intensive study to assess the vulnerability of public-supply wells in the Edwards aquifer to contamination by a variety of compounds. A local-scale, steady-state, three-dimensional numerical groundwater-flow model was developed and used in this study to evaluate the movement of water and solutes from recharge areas to...
Authors
Richard L. Lindgren, Natalie A. Houston, MaryLynn Musgrove, Lynne S. Fahlquist, Leon J. Kauffman
Using Cl/Br ratios and other indicators to assess potential impacts on groundwater quality from septic systems: A review and examples from principal aquifers in the United States Using Cl/Br ratios and other indicators to assess potential impacts on groundwater quality from septic systems: A review and examples from principal aquifers in the United States
A detailed review was made of chemical indicators used to identify impacts from septic tanks on groundwater quality. Potential impacts from septic tank leachate on groundwater quality were assessed using the mass ratio of chloride–bromide (Cl/Br), concentrations of selected chemical constituents, and ancillary information (land use, census data, well depth, soil characteristics) for...
Authors
B. G. Katz, S. M. Eberts, L. J. Kauffman
Relative vulnerability of public supply wells to VOC contamination in hydrologically distinct regional aquifers Relative vulnerability of public supply wells to VOC contamination in hydrologically distinct regional aquifers
A process-based methodology was used to compare the vulnerability of public supply wells tapping seven study areas in four hydrologically distinct regional aquifers to volatile organic compound (VOC) contamination. This method considers (1) contributing areas and travel times of groundwater flowpaths converging at individual supply wells, (2) the oxic and/or anoxic conditions encountered...
Authors
Leon J. Kauffman, Francis H. Chapelle
Simulations of Groundwater Flow and Particle Tracking Analysis in the Area Contributing Recharge to a Public-Supply Well near Tampa, Florida, 2002-05 Simulations of Groundwater Flow and Particle Tracking Analysis in the Area Contributing Recharge to a Public-Supply Well near Tampa, Florida, 2002-05
Shallow ground water in the north-central Tampa Bay region, Florida, is affected by elevated nitrate concentrations, the presence of volatile organic compounds, and pesticides as a result of groundwater development and intensive urban land use. The region relies primarily on groundwater for drinking-water supplies. Sustainability of groundwater quality for public supply requires...
Authors
Christy A. Crandall, Leon J. Kauffman, Brian G. Katz, Patricia A. Metz, W. Scott McBride, Marian P. Berndt
Science and Products
Filter Total Items: 25
Data for depth of groundwater used for drinking-water supplies in the United States (ver. 2.0, January 2026) Data for depth of groundwater used for drinking-water supplies in the United States (ver. 2.0, January 2026)
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...
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) 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...
Data for Three-dimensional distribution of groundwater residence time metrics in the glaciated United States using metamodels trained on general numerical simulation models 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...
Data used to evaluate drinking water quality in the glacial aquifer system, northern USA Data used to evaluate drinking water quality in the glacial aquifer system, northern USA
This data release contains groundwater-quality data and well information for the glacial aquifer system in the northern USA. 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; USGS, 1998, 2002), the U.S. Environmental Protection Agency (USEPA) Safe Drinking Water...
Data and Scripts for Metamodeling for Groundwater Age Forecasting in the Lake Michigan Basin Data and Scripts for Metamodeling for Groundwater Age Forecasting in the Lake Michigan Basin
Groundwater age is an important indicator of groundwater susceptibility to anthropogenic contamination and a key input to statistical models for forecasting water quality. Numerical models can provide estimates of groundwater age, enabling interpretation of measured age tracers. However, to extend to national-scale groundwater systems where numerical models are not routinely available, a...
Digital products from a hydrogeologic framework for Quaternary sediments within the glaciated conterminous United States Digital products from a hydrogeologic framework for Quaternary sediments within the glaciated conterminous United States
This data release is a compilation of the digital products from a hydrogeologic framework of the glaciated conterminous United States that were constructed to portray sediment and aquifer characteristics within this area. These digital products are described in Yager, R.M., Kauffman, L.J., Soller, D.R., Haj, A.E., Heisig, P.M., Buchwald, C.A., Westenbroek, S.M., and Reddy, J.E., 2018
Filter Total Items: 41
On modeling weak sinks in MODPATH On modeling weak sinks in MODPATH
Regional groundwater flow systems often contain both strong sinks and weak sinks. A strong sink extracts water from the entire aquifer depth, while a weak sink lets some water pass underneath or over the actual sink. The numerical groundwater flow model MODFLOW may allow a sink cell to act as a strong or weak sink, hence extracting all water that enters the cell or allowing some of that...
Authors
Daniel B. Abrams, Henk Haitjema, Leon J. Kauffman
Modeling the potential impact of seasonal and inactive multi-aquifer wells on contaminant movement to public water-supply wells Modeling the potential impact of seasonal and inactive multi-aquifer wells on contaminant movement to public water-supply wells
Wells screened across multiple aquifers can provide pathways for the movement of surprisingly large volumes of groundwater to confined aquifers used for public water supply (PWS). Using a simple numerical model, we examine the impact of several pumping scenarios on leakage from an unconfined aquifer to a confined aquifer and conclude that a single inactive multi-aquifer well can...
Authors
R.L. Johnson, B.R. Clark, M.K. Landon, L. J. Kauffman, S. M. Eberts
Simulations of groundwater flow and particle-tracking analysis in the zone of contribution to a public-supply well in San Antonio, Texas Simulations of groundwater flow and particle-tracking analysis in the zone of contribution to a public-supply well in San Antonio, Texas
In 2006, a public-supply well in San Antonio, Texas, was selected for intensive study to assess the vulnerability of public-supply wells in the Edwards aquifer to contamination by a variety of compounds. A local-scale, steady-state, three-dimensional numerical groundwater-flow model was developed and used in this study to evaluate the movement of water and solutes from recharge areas to...
Authors
Richard L. Lindgren, Natalie A. Houston, MaryLynn Musgrove, Lynne S. Fahlquist, Leon J. Kauffman
Using Cl/Br ratios and other indicators to assess potential impacts on groundwater quality from septic systems: A review and examples from principal aquifers in the United States Using Cl/Br ratios and other indicators to assess potential impacts on groundwater quality from septic systems: A review and examples from principal aquifers in the United States
A detailed review was made of chemical indicators used to identify impacts from septic tanks on groundwater quality. Potential impacts from septic tank leachate on groundwater quality were assessed using the mass ratio of chloride–bromide (Cl/Br), concentrations of selected chemical constituents, and ancillary information (land use, census data, well depth, soil characteristics) for...
Authors
B. G. Katz, S. M. Eberts, L. J. Kauffman
Relative vulnerability of public supply wells to VOC contamination in hydrologically distinct regional aquifers Relative vulnerability of public supply wells to VOC contamination in hydrologically distinct regional aquifers
A process-based methodology was used to compare the vulnerability of public supply wells tapping seven study areas in four hydrologically distinct regional aquifers to volatile organic compound (VOC) contamination. This method considers (1) contributing areas and travel times of groundwater flowpaths converging at individual supply wells, (2) the oxic and/or anoxic conditions encountered...
Authors
Leon J. Kauffman, Francis H. Chapelle
Simulations of Groundwater Flow and Particle Tracking Analysis in the Area Contributing Recharge to a Public-Supply Well near Tampa, Florida, 2002-05 Simulations of Groundwater Flow and Particle Tracking Analysis in the Area Contributing Recharge to a Public-Supply Well near Tampa, Florida, 2002-05
Shallow ground water in the north-central Tampa Bay region, Florida, is affected by elevated nitrate concentrations, the presence of volatile organic compounds, and pesticides as a result of groundwater development and intensive urban land use. The region relies primarily on groundwater for drinking-water supplies. Sustainability of groundwater quality for public supply requires...
Authors
Christy A. Crandall, Leon J. Kauffman, Brian G. Katz, Patricia A. Metz, W. Scott McBride, Marian P. Berndt