National Water Quality Program


The National Water Quality Program provides an understanding of water-quality conditions; whether conditions are getting better or worse over time; and how natural features and human activities affect those conditions.

More about this program

Featured Study: Flow Modification of the Nation's Streams

Featured Study: Flow Modification of the Nation

A new USGS study reports that human management of land and water resources have modified natural patterns of streamflow along more than 1.2 million miles of U.S. streams. Flow modification was associated with losses of native fish or invertebrates.

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Featured Study: Fluoride in Groundwater Used for Drinking

Featured Study: Fluoride in Groundwater Used for Drinking

Fluoride occurs commonly in groundwater used for drinking, but typically at concentrations less than the drinking-water standard for human health, reports a new study, and in many cases below the optimal concentration to prevent tooth decay.

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Date published: June 24, 2020

Pavement is contributing sediment to urban streams

Dirt, sand, and other particulate material on parking lots and streets is washing off into urban streams, reports a new study by the U.S. Geological Survey Regional Stream Quality Assessment. The study used novel particle tracers to determine that particles washed from pavement made up...

Date published: June 18, 2020

Updated Information on Locations of Domestic Well Use

A new USGS geonarrative illustrates where domestic (private) wells are located and how many people are using them, based on the results of a 2019 USGS study. A domestic well typically supplies water to single household. Nearly 40 million people in the United States rely on a domestic (private) well for their drinking-...

Date published: June 8, 2020

USGS fills a knowledge gap for radionuclide occurrence in groundwater

Using recently developed and sensitive laboratory methods, the USGS has documented where the radionuclides lead-210 and polonium-210 occur in principal aquifers of the U.S. used for drinking-water supply, reports a ...


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Year Published: 2019

Hydrocarbons in upland groundwater, Marcellus Shale Region, Northeastern Pennsylvania and Southern New York, USA

Water samples from 50 domestic wells located <1 km (proximal) and >1 km (distal) from shale-gas wells in upland areas of the Marcellus Shale region were analyzed for chemical, isotopic, and groundwater-age tracers. Uplands were targeted because natural mixing with brine and hydrocarbons from deep formations is less common in those areas...

McMahon, Peter B.; Lindsey, Bruce D.; Conlon, Matthew D.; Hunt, Andrew G.; Belitz, Kenneth; Jurgens, Bryant; Varela, Brian

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Year Published: 2019

Estimating domestic well locations and populations served in the contiguous U.S. for years 2000 and 2010

Domestic wells provide drinking water supply for approximately 40 million people in the United States. Knowing the location of these wells, and the populations they serve, is important for identifying heavily used aquifers, locations susceptible to contamination, and populations potentially impacted by poor-quality groundwater. The 1990 census was...

Johnson, Tyler D.; Belitz, Kenneth; Lombard, Melissa

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Year Published: 2019

Assessing water-quality changes in U.S. rivers at multiple geographic scales using results from probabilistic and targeted monitoring

Two commonly used approaches for water quality monitoring are probabilistic and targeted. In a probabilistic approach like the US Environmental Protection Agency’s National Rivers and Streams Assessment, monitoring sites are selected using a statistically representative approach. In a targeted approach like that used by many monitoring...

Sprague, Lori A.; Mitchell, Richard M; Pollard, Amina I.; Falcone, James A.