Groundwater Quality Research

Featured: Lithium in Our Nation's Groundwater

Featured: Lithium in Our Nation

Got lithium? A new USGS study reports that about 45% of public-supply wells and about 37% of U.S. domestic supply wells have concentrations of lithium that could present a potential human-health risk.

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Featured: Updated Information on Groundwater Quality

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

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Science Center Objects

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.

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:

Collecting groundwater data

Collecting groundwater data

  • 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
     Chloride and salinity
     Emerging contaminants
     Volatile organic compounds (VOCs), including MTBE
     Hydraulic fracturing

Drinking and source-water quality
     Domestic (private) supply wells
     Public-supply wells
     Drinking-water taste and odor
     Water-quality benchmarks     

Processes affecting groundwater quality
     Groundwater age dating

How do we do it?  Access USGS publications and manuals on sample-collection methods.

Looking for information on surface-water quality as well?  Explore these links:
     Surface-Water Quality and Ecology
     Surface-Water/Groundwater Interaction