Leslie A DeSimone
Leslie DeSimone is a Hydrologist in the New England Water Science Center.
Leslie serves as the Center Water-Quality Specialist and as an analyst for the National Water-Quality Assessment Project.
Leslie started with USGS in 1988 and has worked on a broad range of studies on topics such as contaminant occurrence and transport in groundwater, surface-water quality trends and loads, and groundwater flow and availability.
Current work includes:
- Machine-learning models of groundwater quality in the mid-Atlantic region
- Technical assistance on water-quality data and studies in New England
- Water-quality database management
Recent work includes:
- National compilations of water quality in U.S. Principal Aquifers and in domestic wells
- Mapping bedrock well yield in eastern Massachusetts
Professional Experience
Hydrologist, U.S. Geological Survey, New England Water Science Center, 1988 to Present
Education and Certifications
Ph.D. Geology, Boston University
M.A. Geology, Boston University
B.A. Geology, St. John's College, Annapolis, MD
Science and Products
Chloride Data for Streams in Connecticut, Massachusetts, and Rhode Island
As part of water-quality data collection activities in New England, water samples are analyzed for chloride in monitoring networks and projects across Connecticut, Massachusetts, and Rhode Island. Chloride is of interest because high concentrations may affect aquatic life in streams or affect water quality of reservoirs and aquifers used for drinking water.
Domestic (Private) Supply Wells
More than 43 million people—about 15 percent of the U.S. population—rely on domestic (private) wells as their source of drinking water. The quality and safety of water from domestic wells are not regulated by the Federal Safe Drinking Water Act or, in most cases, by state laws. Instead, individual homeowners are responsible for maintaining their domestic well systems and for monitoring water...
Groundwater Quality in Principal Aquifers of the Nation, 1991–2010
What’s in your groundwater? Learn about groundwater quality in the Principal Aquifers of nine regions across the United States in informative circulars filled with figures, photos, and water-quality information.
Groundwater Quality in Principal Aquifers of the United States, 1991—2010
A new U.S. Geological Survey (USGS) report summarizes the major findings of national and regional assessments of groundwater quality in 40 Principal Aquifers in the United States. Knowledge of contaminant occurrence and the factors that control contaminant concentrations can ensure the availability and quality of this vital natural resource in the future.
Filter Total Items: 15
Surface Water-Quality Data and Nutrient Loads in Selected Rivers and Wastewater Treatment Facilities in the Connecticut River and Taunton River Study Areas in Massachusetts, 2019-2021 Surface Water-Quality Data and Nutrient Loads in Selected Rivers and Wastewater Treatment Facilities in the Connecticut River and Taunton River Study Areas in Massachusetts, 2019-2021
This U.S. Geological Survey (USGS) data release includes necessary information and data to support the analysis and interpretations of nutrient loading and sources of nitrogen in the associated companion USGS Scientific Investigations Report. This data release includes (1) summary statistics for discrete water-quality data collected at eight water-quality-monitoring stations in the...
Data to Assess Nitrogen Export from Forested Watersheds in and near the Long Island Sound Basin with Weighted Regressions on Time, Discharge, and Season (WRTDS) Data to Assess Nitrogen Export from Forested Watersheds in and near the Long Island Sound Basin with Weighted Regressions on Time, Discharge, and Season (WRTDS)
The U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency's Long Island Sound Study (https://longislandsoundstudy.net), characterized nitrogen export from forested watersheds and whether nitrogen loading has been increasing or decreasing to help inform Long Island Sound management strategies. The Weighted Regressions on Time, Discharge, and Season (WRTDS...
Field, laboratory, and third-party quality-control data associated with sites and analytes monitored by the USGS National Water Quality Network, October 2017 through September 2022 Field, laboratory, and third-party quality-control data associated with sites and analytes monitored by the USGS National Water Quality Network, October 2017 through September 2022
From October 2017 through September 2022, the National Water Quality Network (NWQN) monitored 110 surface-water river and stream sites and more than 1,800 groundwater wells for a large number of water-quality analytes, for which associated quality-control data and corresponding statistical summaries are included in this data release. The quality-control data—for samples that were...
Concentrations of metals and other water quality data for the Assabet and Concord Rivers, Massachusetts, 2008 Concentrations of metals and other water quality data for the Assabet and Concord Rivers, Massachusetts, 2008
This dataset contains water-quality data for stream samples collected by the U.S. Geological Survey at 12 sites on the Assabet and Concord Rivers in eastern Massachusetts in 2008. The samples were collected monthly from June to October, 2008. The water-quality parameters and constituents include field parameters (water temperature, specific conductance, pH, and dissolved oxygen)...
Data and Model Archive for Preliminary Machine Learning Models of Manganese and 1,4-Dioxane in Groundwater on Long Island, New York Data and Model Archive for Preliminary Machine Learning Models of Manganese and 1,4-Dioxane in Groundwater on Long Island, New York
Data and preliminary machine-learning models used to predict manganese and 1,4-dioxane in groundwater on Long Island are documented in this data release. Concentration data used to develop the models were from 910 wells for manganese and 553 wells for 1,4-dioxane, primarily public supply wells, from U.S. Geological Survey, U.S. Environmental Protection Agency (USEPA), and Suffolk County...
Total and Dissolved Organic Carbon Data to Support Implementation of Revised Freshwater Aluminum Water-Quality Criteria in Massachusetts Total and Dissolved Organic Carbon Data to Support Implementation of Revised Freshwater Aluminum Water-Quality Criteria in Massachusetts
This data set contains historical data on concentrations of total and dissolved organic carbon in Massachusetts streams from the U.S. Geological Survey National Water Information System (NWIS) database. The data were compiled from NWIS using site and sample selection criteria to retrieve all publicly available data from surface-water samples that contained analysis of both total and...
Filter Total Items: 37
Nitrate loads and concentrations from forested watersheds and implications for Long Island Sound Nitrate loads and concentrations from forested watersheds and implications for Long Island Sound
Reduction in point sources of nitrogen has led to improvement in water quality of the Long Island Sound (LIS) since 2000, but changes in nonpoint sources are less clear. A significant yet poorly quantified nonpoint nitrogen source is the forested landscape. Because a large proportion of the LIS basin is forested, even small areal inputs from the forested landscape have a large cumulative...
Authors
Alana B. Spaetzel, James B. Shanley, Leslie A. DeSimone, John R. Mullaney
Preliminary machine learning models of manganese and 1,4-dioxane in groundwater on Long Island, New York Preliminary machine learning models of manganese and 1,4-dioxane in groundwater on Long Island, New York
Manganese and 1,4-dioxane in groundwater underlying Long Island, New York, were modeled with machine learning methods to demonstrate the use of these methods for mapping contaminants in groundwater in the Long Island aquifer system. XGBoost, a gradient boosted, ensemble tree method, was applied to data from 910 wells for manganese and 553 wells for 1,4-dioxane. Explanatory variables...
Authors
Leslie A. DeSimone
Surface-water-quality data to support implementation of revised freshwater aluminum water-quality criteria in Massachusetts, 2018–19 Surface-water-quality data to support implementation of revised freshwater aluminum water-quality criteria in Massachusetts, 2018–19
The U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, performed a study to inform the development of the department’s guidelines for the collection and use of water-chemistry data to support calculation of site-dependent aluminum criteria values. The U.S. Geological Survey collected and analyzed discrete water-quality samples at four...
Authors
David S. Armstrong, Jennifer G. Savoie, Leslie A. DeSimone, Kaitlin L. Laabs, Richard O. Carey
Manganese in the Northern Atlantic Coastal Plain aquifer system, eastern USA—Modeling regional occurrence with pH, redox, and machine learning Manganese in the Northern Atlantic Coastal Plain aquifer system, eastern USA—Modeling regional occurrence with pH, redox, and machine learning
Study region: The study was conducted in the Northern Atlantic Coastal Plain aquifer system, eastern USA, an important water supply in a densely populated region. Study focus: Manganese (Mn), an emerging health concern and common nuisance contaminant in drinking water, is mapped and modeled using the XGBoost machine learning method, predictions of pH and redox conditions from previous...
Authors
Leslie A. DeSimone, Katherine Marie Ransom
Machine-learning models to map pH and redox conditions in groundwater in a layered aquifer system, Northern Atlantic Coastal Plain, eastern USA Machine-learning models to map pH and redox conditions in groundwater in a layered aquifer system, Northern Atlantic Coastal Plain, eastern USA
Study region The study was conducted in the Northern Atlantic Coastal Plain aquifer system, in the eastern USA.Study focus Groundwater pH and redox conditions are fundamental chemical characteristics controlling the distribution of many contaminants of concern for drinking water or the ecological health of receiving waters. In this study, pH and redox conditions were modeled and mapped...
Authors
Leslie A. DeSimone, Jason P. Pope, Katherine Marie Ransom
Groundwater-quality data from the National Water-Quality Assessment Project, January through December 2014 and select quality-control data from May 2012 through December 2014 Groundwater-quality data from the National Water-Quality Assessment Project, January through December 2014 and select quality-control data from May 2012 through December 2014
Groundwater-quality data were collected from 559 wells as part of the National Water-Quality Assessment Project of the U.S. Geological Survey National Water-Quality Program from January through December 2014. The data were collected from four types of well networks: principal aquifer study networks, which are used to assess the quality of groundwater used for public water supply; land...
Authors
Terri Arnold, Laura M. Bexfield, MaryLynn Musgrove, Bruce D. Lindsey, Paul E. Stackelberg, Jeannie R. B. Barlow, Leslie A. DeSimone, Justin T. Kulongoski, James A. Kingsbury, Joseph D. Ayotte, Brandon J. Fleming, Kenneth Belitz
Science and Products
Chloride Data for Streams in Connecticut, Massachusetts, and Rhode Island
As part of water-quality data collection activities in New England, water samples are analyzed for chloride in monitoring networks and projects across Connecticut, Massachusetts, and Rhode Island. Chloride is of interest because high concentrations may affect aquatic life in streams or affect water quality of reservoirs and aquifers used for drinking water.
Domestic (Private) Supply Wells
More than 43 million people—about 15 percent of the U.S. population—rely on domestic (private) wells as their source of drinking water. The quality and safety of water from domestic wells are not regulated by the Federal Safe Drinking Water Act or, in most cases, by state laws. Instead, individual homeowners are responsible for maintaining their domestic well systems and for monitoring water...
Groundwater Quality in Principal Aquifers of the Nation, 1991–2010
What’s in your groundwater? Learn about groundwater quality in the Principal Aquifers of nine regions across the United States in informative circulars filled with figures, photos, and water-quality information.
Groundwater Quality in Principal Aquifers of the United States, 1991—2010
A new U.S. Geological Survey (USGS) report summarizes the major findings of national and regional assessments of groundwater quality in 40 Principal Aquifers in the United States. Knowledge of contaminant occurrence and the factors that control contaminant concentrations can ensure the availability and quality of this vital natural resource in the future.
Filter Total Items: 15
Surface Water-Quality Data and Nutrient Loads in Selected Rivers and Wastewater Treatment Facilities in the Connecticut River and Taunton River Study Areas in Massachusetts, 2019-2021 Surface Water-Quality Data and Nutrient Loads in Selected Rivers and Wastewater Treatment Facilities in the Connecticut River and Taunton River Study Areas in Massachusetts, 2019-2021
This U.S. Geological Survey (USGS) data release includes necessary information and data to support the analysis and interpretations of nutrient loading and sources of nitrogen in the associated companion USGS Scientific Investigations Report. This data release includes (1) summary statistics for discrete water-quality data collected at eight water-quality-monitoring stations in the...
Data to Assess Nitrogen Export from Forested Watersheds in and near the Long Island Sound Basin with Weighted Regressions on Time, Discharge, and Season (WRTDS) Data to Assess Nitrogen Export from Forested Watersheds in and near the Long Island Sound Basin with Weighted Regressions on Time, Discharge, and Season (WRTDS)
The U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency's Long Island Sound Study (https://longislandsoundstudy.net), characterized nitrogen export from forested watersheds and whether nitrogen loading has been increasing or decreasing to help inform Long Island Sound management strategies. The Weighted Regressions on Time, Discharge, and Season (WRTDS...
Field, laboratory, and third-party quality-control data associated with sites and analytes monitored by the USGS National Water Quality Network, October 2017 through September 2022 Field, laboratory, and third-party quality-control data associated with sites and analytes monitored by the USGS National Water Quality Network, October 2017 through September 2022
From October 2017 through September 2022, the National Water Quality Network (NWQN) monitored 110 surface-water river and stream sites and more than 1,800 groundwater wells for a large number of water-quality analytes, for which associated quality-control data and corresponding statistical summaries are included in this data release. The quality-control data—for samples that were...
Concentrations of metals and other water quality data for the Assabet and Concord Rivers, Massachusetts, 2008 Concentrations of metals and other water quality data for the Assabet and Concord Rivers, Massachusetts, 2008
This dataset contains water-quality data for stream samples collected by the U.S. Geological Survey at 12 sites on the Assabet and Concord Rivers in eastern Massachusetts in 2008. The samples were collected monthly from June to October, 2008. The water-quality parameters and constituents include field parameters (water temperature, specific conductance, pH, and dissolved oxygen)...
Data and Model Archive for Preliminary Machine Learning Models of Manganese and 1,4-Dioxane in Groundwater on Long Island, New York Data and Model Archive for Preliminary Machine Learning Models of Manganese and 1,4-Dioxane in Groundwater on Long Island, New York
Data and preliminary machine-learning models used to predict manganese and 1,4-dioxane in groundwater on Long Island are documented in this data release. Concentration data used to develop the models were from 910 wells for manganese and 553 wells for 1,4-dioxane, primarily public supply wells, from U.S. Geological Survey, U.S. Environmental Protection Agency (USEPA), and Suffolk County...
Total and Dissolved Organic Carbon Data to Support Implementation of Revised Freshwater Aluminum Water-Quality Criteria in Massachusetts Total and Dissolved Organic Carbon Data to Support Implementation of Revised Freshwater Aluminum Water-Quality Criteria in Massachusetts
This data set contains historical data on concentrations of total and dissolved organic carbon in Massachusetts streams from the U.S. Geological Survey National Water Information System (NWIS) database. The data were compiled from NWIS using site and sample selection criteria to retrieve all publicly available data from surface-water samples that contained analysis of both total and...
Filter Total Items: 37
Nitrate loads and concentrations from forested watersheds and implications for Long Island Sound Nitrate loads and concentrations from forested watersheds and implications for Long Island Sound
Reduction in point sources of nitrogen has led to improvement in water quality of the Long Island Sound (LIS) since 2000, but changes in nonpoint sources are less clear. A significant yet poorly quantified nonpoint nitrogen source is the forested landscape. Because a large proportion of the LIS basin is forested, even small areal inputs from the forested landscape have a large cumulative...
Authors
Alana B. Spaetzel, James B. Shanley, Leslie A. DeSimone, John R. Mullaney
Preliminary machine learning models of manganese and 1,4-dioxane in groundwater on Long Island, New York Preliminary machine learning models of manganese and 1,4-dioxane in groundwater on Long Island, New York
Manganese and 1,4-dioxane in groundwater underlying Long Island, New York, were modeled with machine learning methods to demonstrate the use of these methods for mapping contaminants in groundwater in the Long Island aquifer system. XGBoost, a gradient boosted, ensemble tree method, was applied to data from 910 wells for manganese and 553 wells for 1,4-dioxane. Explanatory variables...
Authors
Leslie A. DeSimone
Surface-water-quality data to support implementation of revised freshwater aluminum water-quality criteria in Massachusetts, 2018–19 Surface-water-quality data to support implementation of revised freshwater aluminum water-quality criteria in Massachusetts, 2018–19
The U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, performed a study to inform the development of the department’s guidelines for the collection and use of water-chemistry data to support calculation of site-dependent aluminum criteria values. The U.S. Geological Survey collected and analyzed discrete water-quality samples at four...
Authors
David S. Armstrong, Jennifer G. Savoie, Leslie A. DeSimone, Kaitlin L. Laabs, Richard O. Carey
Manganese in the Northern Atlantic Coastal Plain aquifer system, eastern USA—Modeling regional occurrence with pH, redox, and machine learning Manganese in the Northern Atlantic Coastal Plain aquifer system, eastern USA—Modeling regional occurrence with pH, redox, and machine learning
Study region: The study was conducted in the Northern Atlantic Coastal Plain aquifer system, eastern USA, an important water supply in a densely populated region. Study focus: Manganese (Mn), an emerging health concern and common nuisance contaminant in drinking water, is mapped and modeled using the XGBoost machine learning method, predictions of pH and redox conditions from previous...
Authors
Leslie A. DeSimone, Katherine Marie Ransom
Machine-learning models to map pH and redox conditions in groundwater in a layered aquifer system, Northern Atlantic Coastal Plain, eastern USA Machine-learning models to map pH and redox conditions in groundwater in a layered aquifer system, Northern Atlantic Coastal Plain, eastern USA
Study region The study was conducted in the Northern Atlantic Coastal Plain aquifer system, in the eastern USA.Study focus Groundwater pH and redox conditions are fundamental chemical characteristics controlling the distribution of many contaminants of concern for drinking water or the ecological health of receiving waters. In this study, pH and redox conditions were modeled and mapped...
Authors
Leslie A. DeSimone, Jason P. Pope, Katherine Marie Ransom
Groundwater-quality data from the National Water-Quality Assessment Project, January through December 2014 and select quality-control data from May 2012 through December 2014 Groundwater-quality data from the National Water-Quality Assessment Project, January through December 2014 and select quality-control data from May 2012 through December 2014
Groundwater-quality data were collected from 559 wells as part of the National Water-Quality Assessment Project of the U.S. Geological Survey National Water-Quality Program from January through December 2014. The data were collected from four types of well networks: principal aquifer study networks, which are used to assess the quality of groundwater used for public water supply; land...
Authors
Terri Arnold, Laura M. Bexfield, MaryLynn Musgrove, Bruce D. Lindsey, Paul E. Stackelberg, Jeannie R. B. Barlow, Leslie A. DeSimone, Justin T. Kulongoski, James A. Kingsbury, Joseph D. Ayotte, Brandon J. Fleming, Kenneth Belitz