Our surface water, groundwater, and aquatic ecosystems are priceless resources, used by people across the Nation for drinking, irrigation, industry, and recreation. The National Water-Quality Assessment (NAWQA) Project is a leading source of scientific data and knowledge for development of science-based policies and management strategies to improve and protect our water resources.
Featured: Deciphering the U.S. urban stream pesticide signature
A new USGS study reports that 16 dissolved pesticides were consistently detected in small streams in 16 urban centers across five regions of the United States.
Featured: Potential pesticide toxicity to aquatic life is widespread
A new USGS study of pesticides in U.S. rivers and streams reports that, on average, 17 pesticides were detected at least once at the 74 river and stream sites sampled 12 to 24 times per year during 2013–2017.
Quick Links
Looking for data? Maps? Use these links to quickly access some of the most frequently visited USGS web pages on water quality.
In 1991, Congress established the National Water-Quality Assessment (NAWQA) Project to address where, when, why, and how the Nation's water quality has changed, or is likely to change in the future, in response to human activities and natural factors. Since then, NAWQA has produced scientific data and knowledge that is used by national, regional, state, and local agencies to develop science-based policies and management strategies to improve and protect water resources used for drinking water, recreation, irrigation, energy development, and ecosystem needs. A prominent feature of NAWQA is the development of long-term consistent and comparable information on streams, rivers, ground water, and aquatic systems. The NAWQA Project is designed to answer these questions:
- What is the current condition of our Nation's streams, rivers, and groundwater?
- How are these conditions changing over time?
- How do natural features and human activities affect these conditions, and where are those effects most pronounced?
NAWQA Water-Quality Research
SURFACE WATER AND ECOLOGY
Water Quality and Ecology of Small Streams (RSQA)
The Regional Stream Quality Assessment (RSQA) is studying the relations between stressors (chemical and physical) and stream ecology (fish, algae, and aquatic invertebrates) at small streams in five large regions of the United States. Users can access an online mapping tool to compare water quality at small streams across a region, see scorecards that summarize stream health at each stream site, and download data for hundreds of chemical compounds.
Water Quality in the Nation's Streams and Rivers: Current Conditions and Long-Term Trends
Knowing the current water-quality conditions of our rivers and streams and where those conditions have improved or deteriorated is critical information for resource managers and the public. An online water-quality tracking tool shows graphs of pesticides, nutrients, and sediment in streams, and users can download data for a streams and rivers across the country; the tool is updated annually. The online water-quality trends mapping tool allows users to visualize trends in water chemistry (nutrients, pesticides, sediment, carbon, and salinity) and aquatic ecology (fish, invertebrates, and algae).
SPARROW modeling: Estimating nutrient, sediment, and dissolved solids transport
SPARROW (SPAtially Referenced Regression On Watershed attributes) models estimate the amount of a contaminant transported from inland watersheds to larger water bodies by linking monitoring data with information on watershed characteristics and contaminant sources. Users can explore relations between human activities, natural processes, and contaminant transport using interactive mappers.
GROUNDWATER
Groundwater Quality: Current Conditions and Changes Through Time
Scientists are characterizing groundwater quality in principal aquifers, the primary source of the Nation's groundwater used for drinking. Concentrations of inorganic constituents, such as arsenic and nitrate, and organic constituents, such as pesticides and volatile organic compounds, are compared to benchmarks established for the protection of human health. Users can access an online tool to see how concentrations of pesticides, nutrients, metals, and organic contaminants in groundwater are changing during decadal periods across the Nation, and see in real time how chemical properties of groundwater at some sites are fluctuating.
Groundwater Quality: Predictions for Unmonitored Areas
Groundwater hydrologists are developing statistical models that predict where a contaminant is likely to occur in groundwater and at what concentration. These models extrapolate groundwater quality in areas and at depths where groundwater has not yet been sampled. Users can see predicted contaminant concentrations in map view, and—for some aquifers—in 3-D.
SURFACE WATER/GROUNDWATER INTERACTION
Groundwater/Surface-Water Interaction
Surface water and groundwater are intimately connected and are constantly interacting. The Integrated Watershed Studies team is quantifying how water and chemicals move between the landscape, streams and rivers, and groundwater. Learn how the quantity and quality of surface water and groundwater are likely to change in response to changes in climate, land use, and best management practices.
NAWQA — The First Two Decades
From 1991-2001, the NAWQA Project conducted interdisciplinary assessments, including water chemistry, hydrology, land use, stream habitat, and aquatic life, and established a baseline understanding of water-quality conditions in 51 of the Nation's river basins and aquifers, referred to as Study Units.
From 2001-2012, NAWQA focused on specific water-quality topics of national interest, such as pesticides, nutrients, and aquatic ecology, as well as continuing to monitor and assess 42 of the Study Units.
► Learn about the first two decades of NAWQA research and access information and publications about the quality of the Nation's surface-water and groundwater resources.
How do we do it?
Find methods used by NAWQA to assesses the current quality of our surface water and groundwater.
► Documentation on water-quality sample collection methods developed by NAWQA.
Explore Related Topics on Water-Quality Research
RELATIONS BETWEEN LAND USE AND WATER QUALITY
Urban Land Use and Water Quality
Agricultural Contamination
CONTAMINANTS IN WATER
Arsenic and Drinking Water
Chloride, salinity, and dissolved solids
Emerging contaminants (including pharmaceuticals and hormones)
Mercury
Metals and Other Trace Elements
Nutrients and Eutrophication
National Atmospheric Deposition Program (NADP)
Pesticides and Water Quality
Coal-Tar-Based Pavement Sealcoat, PAHs, and Environmental Health
Radionuclides
Sediment-associated contaminants
Volatile organic compounds (VOCs) (including MTBE)
DRINKING WATER ISSUES
Corrosivity
Domestic (private) supply wells
Public-supply wells
Drinking-water taste and odor
Water-Quality Benchmarks for Contaminants
Drinking Water and Source Water Research
RELATIONS TO AQUATIC LIFE
Stream ecology
Mercury
Streamflow Alteration
NWQP Research on Harmful Algal Blooms (HABs)
TRENDS IN WATER QUALITY
Water-quality trends
Water-quality trends from lake sediment cores
PROCESSES
Oxidation/Reduction (Redox)
Groundwater Age
► Confused by some of the water-quality terms? Find the definitions and explanations you're looking for in the Water-Quality Glossary.
Learn more about some of the research associated with the National Water Quality Assessment project.
New Water-Quality Directions
NWQP Research on Harmful Algal Blooms (HABs)
Nutrients and Eutrophication
Drinking Water and Source Water Research
Urban Land Use and Water Quality
NWQP Water-Quality Topics
Emerging Contaminants
Groundwater Quality Research
Groundwater/Surface-Water Interaction
Hydraulic Fracturing
Agriculture and the Quality of the Nation's Waters
Acid Rain
Isotopic tracers in fish in Northeast provide clue to mercury sources
Isotopes of mercury in fish can indicate the source of that mercury, reports a new study from the USGS Regional Stream Quality Assessment.
- Overview
Our surface water, groundwater, and aquatic ecosystems are priceless resources, used by people across the Nation for drinking, irrigation, industry, and recreation. The National Water-Quality Assessment (NAWQA) Project is a leading source of scientific data and knowledge for development of science-based policies and management strategies to improve and protect our water resources.
Featured: Deciphering the U.S. urban stream pesticide signature
A new USGS study reports that 16 dissolved pesticides were consistently detected in small streams in 16 urban centers across five regions of the United States.
Featured: Potential pesticide toxicity to aquatic life is widespread
A new USGS study of pesticides in U.S. rivers and streams reports that, on average, 17 pesticides were detected at least once at the 74 river and stream sites sampled 12 to 24 times per year during 2013–2017.
Quick LinksLooking for data? Maps? Use these links to quickly access some of the most frequently visited USGS web pages on water quality.
In 1991, Congress established the National Water-Quality Assessment (NAWQA) Project to address where, when, why, and how the Nation's water quality has changed, or is likely to change in the future, in response to human activities and natural factors. Since then, NAWQA has produced scientific data and knowledge that is used by national, regional, state, and local agencies to develop science-based policies and management strategies to improve and protect water resources used for drinking water, recreation, irrigation, energy development, and ecosystem needs. A prominent feature of NAWQA is the development of long-term consistent and comparable information on streams, rivers, ground water, and aquatic systems. The NAWQA Project is designed to answer these questions:
- What is the current condition of our Nation's streams, rivers, and groundwater?
- How are these conditions changing over time?
- How do natural features and human activities affect these conditions, and where are those effects most pronounced?
NAWQA Water-Quality Research
SURFACE WATER AND ECOLOGY
Water Quality and Ecology of Small Streams (RSQA)
The Regional Stream Quality Assessment (RSQA) is studying the relations between stressors (chemical and physical) and stream ecology (fish, algae, and aquatic invertebrates) at small streams in five large regions of the United States. Users can access an online mapping tool to compare water quality at small streams across a region, see scorecards that summarize stream health at each stream site, and download data for hundreds of chemical compounds.Water Quality in the Nation's Streams and Rivers: Current Conditions and Long-Term Trends
Knowing the current water-quality conditions of our rivers and streams and where those conditions have improved or deteriorated is critical information for resource managers and the public. An online water-quality tracking tool shows graphs of pesticides, nutrients, and sediment in streams, and users can download data for a streams and rivers across the country; the tool is updated annually. The online water-quality trends mapping tool allows users to visualize trends in water chemistry (nutrients, pesticides, sediment, carbon, and salinity) and aquatic ecology (fish, invertebrates, and algae).SPARROW modeling: Estimating nutrient, sediment, and dissolved solids transport
SPARROW (SPAtially Referenced Regression On Watershed attributes) models estimate the amount of a contaminant transported from inland watersheds to larger water bodies by linking monitoring data with information on watershed characteristics and contaminant sources. Users can explore relations between human activities, natural processes, and contaminant transport using interactive mappers.
Sources/Usage: Public Domain.From left: Aquatic sampling during Southeast Stream Quality Assessment; velocity measurement at Truckee River, Nevada; wrestling with cages of fathead minnows in Goodwater Creek, Missouri, during high flow. GROUNDWATER
Groundwater Quality: Current Conditions and Changes Through Time
Scientists are characterizing groundwater quality in principal aquifers, the primary source of the Nation's groundwater used for drinking. Concentrations of inorganic constituents, such as arsenic and nitrate, and organic constituents, such as pesticides and volatile organic compounds, are compared to benchmarks established for the protection of human health. Users can access an online tool to see how concentrations of pesticides, nutrients, metals, and organic contaminants in groundwater are changing during decadal periods across the Nation, and see in real time how chemical properties of groundwater at some sites are fluctuating.Groundwater Quality: Predictions for Unmonitored Areas
Groundwater hydrologists are developing statistical models that predict where a contaminant is likely to occur in groundwater and at what concentration. These models extrapolate groundwater quality in areas and at depths where groundwater has not yet been sampled. Users can see predicted contaminant concentrations in map view, and—for some aquifers—in 3-D.
Sources/Usage: Public Domain.From left: measuring groundwater salinity in Georgia; collecting groundwater samples for laboratory analysis in Florida; sampling shallow groundwater wells for an agricultural land-use study in Georgia; collecting groundwater samples in Nevada. SURFACE WATER/GROUNDWATER INTERACTION
Groundwater/Surface-Water Interaction
Surface water and groundwater are intimately connected and are constantly interacting. The Integrated Watershed Studies team is quantifying how water and chemicals move between the landscape, streams and rivers, and groundwater. Learn how the quantity and quality of surface water and groundwater are likely to change in response to changes in climate, land use, and best management practices.
Sources/Usage: Public Domain.From left: Installing shallow groundwater wells at ephemeral ponds; the Alapaha River , a "losing" stream at low flow; marking groundwater seeps. (Credit: Alan Cressler, USGS) NAWQA — The First Two Decades
From 1991-2001, the NAWQA Project conducted interdisciplinary assessments, including water chemistry, hydrology, land use, stream habitat, and aquatic life, and established a baseline understanding of water-quality conditions in 51 of the Nation's river basins and aquifers, referred to as Study Units.
From 2001-2012, NAWQA focused on specific water-quality topics of national interest, such as pesticides, nutrients, and aquatic ecology, as well as continuing to monitor and assess 42 of the Study Units.
► Learn about the first two decades of NAWQA research and access information and publications about the quality of the Nation's surface-water and groundwater resources.
Sources/Usage: Public Domain.How do we do it?
Find methods used by NAWQA to assesses the current quality of our surface water and groundwater.
► Documentation on water-quality sample collection methods developed by NAWQA.
Explore Related Topics on Water-Quality Research
RELATIONS BETWEEN LAND USE AND WATER QUALITY
Urban Land Use and Water Quality
Agricultural ContaminationCONTAMINANTS IN WATER
Arsenic and Drinking Water
Chloride, salinity, and dissolved solids
Emerging contaminants (including pharmaceuticals and hormones)
Mercury
Metals and Other Trace Elements
Nutrients and Eutrophication
National Atmospheric Deposition Program (NADP)
Pesticides and Water Quality
Coal-Tar-Based Pavement Sealcoat, PAHs, and Environmental Health
Radionuclides
Sediment-associated contaminants
Volatile organic compounds (VOCs) (including MTBE)DRINKING WATER ISSUES
Corrosivity
Domestic (private) supply wells
Public-supply wells
Drinking-water taste and odor
Water-Quality Benchmarks for Contaminants
Drinking Water and Source Water ResearchRELATIONS TO AQUATIC LIFE
Stream ecology
Mercury
Streamflow Alteration
NWQP Research on Harmful Algal Blooms (HABs)TRENDS IN WATER QUALITY
Water-quality trends
Water-quality trends from lake sediment coresPROCESSES
Oxidation/Reduction (Redox)
Groundwater Age► Confused by some of the water-quality terms? Find the definitions and explanations you're looking for in the Water-Quality Glossary.
- Science
Learn more about some of the research associated with the National Water Quality Assessment project.
Filter Total Items: 33New Water-Quality Directions
As the USGS Water Resources Mission Area looks to the future, we are updating our water programs to meet 21st century water-resource challenges. As part of these updates, we are integrating the National Water Quality Assessment Project's water-resource monitoring, assessment, trends, modeling, and forecasting activities into new WMA programs.NWQP Research on Harmful Algal Blooms (HABs)
Harmful algal blooms (HABs) are caused by a complex set of physical, chemical, biological, hydrological, and meteorological conditions. Many unanswered questions remain about occurrence, environmental triggers for toxicity, and the ability to predict the timing, duration, and toxicity of HABs.Nutrients and Eutrophication
Like people, plants need nutrients, but too much of a good thing can be a problem. Nutrients, such as nitrogen and phosphorus, occur naturally, but most of the nutrients in our waterways come from human activities and sources—fertilizers, wastewater, automobile exhaust, animal waste. The USGS investigates the source, transport, and fate of nutrients and their impacts on the world around us.Drinking Water and Source Water Research
Reliable drinking water is vital for the health and safety of all Americans. The USGS monitors and assesses the quality of the water used as a source for our nation's drinking water needs.Urban Land Use and Water Quality
Wherever you live, there’s a creek or stream near you. The eighty percent of Americans who live in metropolitan areas are often unaware of the network of urban creeks—many teeming with life—that weaves through our cities and town. Nowhere are the environmental changes associated with urban development more evident than in urban streams.NWQP Water-Quality Topics
From chloride to corrosivity, from pesticides to PAHs, find the most recent National Water Quality Program (NWQP) science on these topics and effects on surface water, groundwater, and ecology. Informative web pages provide an overview and links to related web pages, publications, maps, news, and data.Emerging Contaminants
Emerging contaminants, or contaminants of emerging concern, can refer to many different kinds of chemicals, including medicines, personal care or household cleaning products, lawn care and agricultural products, among others. These chemicals make it into our Nation's lakes and rivers and have a detrimental affect on fish and other aquatic species. That have also been shown to bioaccumulate up the...Groundwater Quality Research
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/Surface-Water Interaction
Water and the chemicals it contains are constantly being exchanged between the land surface and the subsurface. Surface water seeps into the ground and recharges the underlying aquifer—groundwater discharges to the surface and supplies the stream with baseflow. USGS Integrated Watershed Studies assess these exchanges and their effect on surface-water and groundwater quality and quantity.Hydraulic Fracturing
Hydraulic fracturing, commonly known as fracking, is the process of injecting water, sand, and/or chemicals into a well to break up underground bedrock to free up oil or gas reserves. The USGS monitors the environmental impact of this practice across the country, from potential earthquakes to degraded groundwater quality.Agriculture and the Quality of the Nation's Waters
Intensive studies by the USGS National Water-Quality Assessment (NAWQA) Project in agricultural areas provide insight into how agricultural activities have altered the natural flow of water and the way that agricultural chemicals enter streams and aquifers, and in particular how nutrients affect algal and invertebrate communities in agricultural streams.Acid Rain
The USGS has been at the forefront of studying the impacts of acid rain for decades. How does acid rain form? What does it do to the landscape? Can it burn you like battery acid? Keep reading to find out more... - Data
- Multimedia
- Publications
- Web Tools
- Software
- News
Isotopic tracers in fish in Northeast provide clue to mercury sources
Isotopes of mercury in fish can indicate the source of that mercury, reports a new study from the USGS Regional Stream Quality Assessment.