Groundwater—Our Invisible, Vital Resource
What’s in Our Groundwater?—Current Conditions and Changes
Learn about groundwater quality in Principal Aquifers across the Nation and how it's changed over time
Predicting Groundwater Quality in Unmonitored Areas
See where a contaminant is likely to occur and at what concentration
Is Groundwater Quality Getting Better or Worse?
Use the web-based tool to see how groundwater quality across the Nation has changed over the decades
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.
Featured: 3-D Models of As and Mn in the Glacial Aquifer System
New 3-D models from the USGS National Water Quality Program predict where high concentrations of arsenic and manganese likely occur in the glacial aquifer system, groundwater supply for 30 million. Redox conditions and pH are controlling factors.
Featured: Updated Information on Groundwater Quality
Three new USGS fact sheets update information on groundwater quality in the nation's most heavily used aquifers. Fact sheets are now available for the Edwards-Trinity aquifer system, the Stream Valley aquifers, and the Colorado Plateau aquifers.
Groundwater is our invisible, vital resource. The USGS National Water Quality Program (NWQP) is focusing on studies of principal aquifers, regionally extensive aquifers that are critical sources of groundwater used for public supply. The studies have two main thrusts:
- Current conditions and changes through time. These assessments characterize groundwater quality in principal aquifers, comparing concentrations of inorganic constituents, such as arsenic and nitrate, and organic constituents, such as pesticides and volatile organic compounds, to benchmarks established for the protection of human health. Tracking changes in groundwater quality through time and investigating the reasons for these changes is crucial for informing management decisions to protect and sustain our valuable groundwater resources. See how concentrations of metals, nutrients, pesticides, and organic contaminants in groundwater are changing during decadal periods across the Nation, and view real-time fluctuations in groundwater quality.
- Predicting groundwater quality. Statistical models and 3-D characterizations predict where a contaminant is likely to occur in groundwater, at what depth, and at what concentration. These forecasts anticipate water quality in areas where groundwater has not been sampled.
From 1991 to 2010, about 6,600 wells were sampled by the NWQP to document where contaminants occur and to develop an understanding of the natural and human factors that affect the occurrence of contaminants in the Nation’s groundwater. Learn about groundwater quality in the Nation’s principal aquifers, 1991–2010.
Explore USGS science on topics related to groundwater quality:
National Water Quality Assessment (NAWQA) Project
Contaminants in groundwater
Arsenic and Drinking Water
Chloride, Salinity, and Dissolved Solids
Emerging Contaminants
Metals and Other Trace Elements
Nutrients and Eutrophication
Pesticides and Water Quality
Radionuclides
Volatile organic compounds (VOCs)
Hydraulic Fracturing
Drinking and source-water quality
Corrosivity
Domestic (private) supply wells
Public-supply wells
Drinking-water taste and odor
Water-Quality Benchmarks for Contaminants
Processes affecting groundwater quality
Groundwater Age
Oxidation/Reduction (Redox)
How do we do it? Access USGS publications and manuals on National Water-Quality Project sampling methods.
Looking for information on surface-water quality as well? Explore these links:
Surface-Water Quality and Ecology
Groundwater/Surface-Water Interaction
National Water-Quality Assessment (NAWQA)
Nutrients and Eutrophication
Drinking Water and Source Water Research
Groundwater/Surface-Water Interaction
Hydraulic Fracturing
Chloride, Salinity, and Dissolved Solids
Arsenic and Drinking Water
Pesticides and Water Quality
Metals and Other Trace Elements
Corrosivity
Public Supply Wells
Domestic (Private) Supply Wells
Contaminants present in many parts of the Glacial aquifer system
Are you one of 30 million Americans whose drinking-water supply relies on groundwater from the glacial aquifer system? A new USGS study assesses the quality of untreated groundwater from this critical water resource, which underlies parts of 25 northern U.S. states.
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.
Featured: 3-D Models of As and Mn in the Glacial Aquifer System
New 3-D models from the USGS National Water Quality Program predict where high concentrations of arsenic and manganese likely occur in the glacial aquifer system, groundwater supply for 30 million. Redox conditions and pH are controlling factors.
Featured: Updated Information on Groundwater Quality
Three new USGS fact sheets update information on groundwater quality in the nation's most heavily used aquifers. Fact sheets are now available for the Edwards-Trinity aquifer system, the Stream Valley aquifers, and the Colorado Plateau aquifers.
Groundwater is our invisible, vital resource. The USGS National Water Quality Program (NWQP) is focusing on studies of principal aquifers, regionally extensive aquifers that are critical sources of groundwater used for public supply. The studies have two main thrusts:
- Current conditions and changes through time. These assessments characterize groundwater quality in principal aquifers, comparing concentrations of inorganic constituents, such as arsenic and nitrate, and organic constituents, such as pesticides and volatile organic compounds, to benchmarks established for the protection of human health. Tracking changes in groundwater quality through time and investigating the reasons for these changes is crucial for informing management decisions to protect and sustain our valuable groundwater resources. See how concentrations of metals, nutrients, pesticides, and organic contaminants in groundwater are changing during decadal periods across the Nation, and view real-time fluctuations in groundwater quality.
- Predicting groundwater quality. Statistical models and 3-D characterizations predict where a contaminant is likely to occur in groundwater, at what depth, and at what concentration. These forecasts anticipate water quality in areas where groundwater has not been sampled.
From 1991 to 2010, about 6,600 wells were sampled by the NWQP to document where contaminants occur and to develop an understanding of the natural and human factors that affect the occurrence of contaminants in the Nation’s groundwater. Learn about groundwater quality in the Nation’s principal aquifers, 1991–2010.
Explore USGS science on topics related to groundwater quality:
National Water Quality Assessment (NAWQA) Project
Contaminants in groundwater
Arsenic and Drinking Water
Chloride, Salinity, and Dissolved Solids
Emerging Contaminants
Metals and Other Trace Elements
Nutrients and Eutrophication
Pesticides and Water Quality
Radionuclides
Volatile organic compounds (VOCs)
Hydraulic Fracturing
Drinking and source-water quality
Corrosivity
Domestic (private) supply wells
Public-supply wells
Drinking-water taste and odor
Water-Quality Benchmarks for Contaminants
Processes affecting groundwater quality
Groundwater Age
Oxidation/Reduction (Redox)
How do we do it? Access USGS publications and manuals on National Water-Quality Project sampling methods.
Looking for information on surface-water quality as well? Explore these links:
Surface-Water Quality and Ecology
Groundwater/Surface-Water Interaction
National Water-Quality Assessment (NAWQA)
Nutrients and Eutrophication
Drinking Water and Source Water Research
Groundwater/Surface-Water Interaction
Hydraulic Fracturing
Chloride, Salinity, and Dissolved Solids
Arsenic and Drinking Water
Pesticides and Water Quality
Metals and Other Trace Elements
Corrosivity
Public Supply Wells
Domestic (Private) Supply Wells
Contaminants present in many parts of the Glacial aquifer system
Are you one of 30 million Americans whose drinking-water supply relies on groundwater from the glacial aquifer system? A new USGS study assesses the quality of untreated groundwater from this critical water resource, which underlies parts of 25 northern U.S. states.