National Water Quality Program
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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.
Featured Study: Insights into changes in chloride in streams
A joint USEPA-USGS study finds that integrating water-quality sampling approaches can provide insight into changing chloride concentrations in U.S. streams and rivers.
Learn moreFeatured Study: Potential lead solubility in groundwater
About one-third of more than 8,300 wells tested across the U.S. had groundwater with chemical characteristics that could cause lead, if present in plumbing, to leach into tap water at levels above the EPA Action Level.
Learn MoreNews
Nitrate loads entering the Gulf of Mexico have not changed despite reductions at local scales
Reducing delivery of nitrate to the Gulf of Mexico is critical to decreasing the size of the “dead zone”—an area of hypoxia, or low dissolved oxygen—in Louisiana coastal waters. A new USGS study reports that larger, more widespread decreases in nitrate loading to the Gulf are needed to achieve the target levels of a 25% reduction by...
New USGS online tools for watershed managers
SPARROW models, tools, and maps of streamflow, nutrients, and sediment for streams in five major U.S. regions
Herbicide glyphosate prevalent in U.S. streams and rivers
The herbicide glyphosate was detected at least once in 66 of 70 U.S. streams and rivers located in a range of land-use settings, according to a recent study by the U.S. Geological Survey National Water Quality Program. Glyphosate is the active ingredient in the popular weed killer Roundup® and is the most widely used herbicide in...
Publications
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 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 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.