A new online interactive mapping tool provides summaries of decadal-scale changes in groundwater chemistry across the Nation.
About 140 million people—almost one-half of the Nation's population—rely on groundwater for drinking water. Tracking changes in groundwater quality and investigating the reasons for these changes are crucial for informing management decisions to protect and sustain our valuable groundwater resources.
The interactive mapping tool is based on data from over 5,000 wells sampled between 1988 and 2020 in a series of 67 networks across the United States by the National Water-Quality Assessment Project. Each groundwater network consists of about 20 to 30 wells. Networks were chosen based on geographic distribution across the Nation to represent the most important water-supply aquifers and specific land use types.
This tool can be used to:
- Track how concentrations of 24 contaminants (such as nutrients, pesticides, metals, and volatile organic compounds) are changing over decadal periods
- View the distribution of wells sampled within an aquifer
- Download water-quality data
- Learn more about the statistical approaches used to track decadal changes in groundwater quality.
The U.S. Geological Survey (USGS) National Water-Quality Assessment Project provided the funds to develop the online tool.
See below for related data.
Data from Decadal Change in Groundwater Quality Web Site, 1988-2018
Data from Decadal Change in Groundwater Quality Web Site, 1988-2014, Version 2.0
See below for related web applications.
- Overview
A new online interactive mapping tool provides summaries of decadal-scale changes in groundwater chemistry across the Nation.
About 140 million people—almost one-half of the Nation's population—rely on groundwater for drinking water. Tracking changes in groundwater quality and investigating the reasons for these changes are crucial for informing management decisions to protect and sustain our valuable groundwater resources.
Increases in chloride concentrations were observed in thirty-one groundwater networks across the Nation. The online mapper examines decadal changes in 24 contaminants, such as nutrients, pesticides, metals, and volatile organic compounds. The interactive mapping tool is based on data from over 5,000 wells sampled between 1988 and 2020 in a series of 67 networks across the United States by the National Water-Quality Assessment Project. Each groundwater network consists of about 20 to 30 wells. Networks were chosen based on geographic distribution across the Nation to represent the most important water-supply aquifers and specific land use types.
This tool can be used to:
- Track how concentrations of 24 contaminants (such as nutrients, pesticides, metals, and volatile organic compounds) are changing over decadal periods
- View the distribution of wells sampled within an aquifer
- Download water-quality data
- Learn more about the statistical approaches used to track decadal changes in groundwater quality.
The U.S. Geological Survey (USGS) National Water-Quality Assessment Project provided the funds to develop the online tool.
- Data
See below for related data.
Data from Decadal Change in Groundwater Quality Web Site, 1988-2018
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 between 20Data from Decadal Change in Groundwater Quality Web Site, 1988-2014, Version 2.0
Evaluating Decadal Changes in Groundwater Quality: Groundwater quality data were collected from 5,000 wells between 1988-2001 (first sampling event) by the U.S. Geological Survey's 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 about 10 years later betwee - Web Tools
See below for related web applications.