Water-Quality Trends Active
Access data for water-quality trends in U.S. streams and rivers
110 stream and river sites with long-term, consistent data on water quality
Is water quality getting better or worse? Answering this deceptively simple question has been a fundamental objective of the USGS National Water-Quality Assessment Project’s research. Learn about trends in contaminants in the nation’s streams and rivers, trends in contaminants that collect in the bed sediment of streams and lakes, and changes in the quality of the nation’s groundwater.
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. In response, the NAWQA Project developed multi-pronged approaches to characterize trends in diverse contaminants in the Nation’s streams, rivers, bed sediment, and groundwater.
Trends in Contaminant Concentrations and Loads in the Nation’s Streams and Rivers
The NAWQA Project, other USGS programs, and other Federal, State, and local agencies have collected years of water-quality data to support their assessments of changing water-quality conditions. For the first time, all of these data have been combined to support the most comprehensive assessment conducted to date of water-quality trends in the United States. Collectively, these data provide insight into how natural features and human activities have contributed to water-quality changes over time in Nation's streams and rivers. Data are 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)
Trends in Sediment-Associated Contaminants
Many contaminants adhere, or sorb, to sediment, so that standard water-quality sampling and analysis is often unable to detect changes in their concentrations over time. Sediment-associated contaminants include legacy contaminants, such as DDT and PCBs, and contaminants currently released into the environment, such as the pesticide bifenthrin and polycyclic aromatic hydrocarbons (PAHs). An alternative approach to determine trends in concentrations of these contaminants is the use of sediment cores collected from lakes and reservoirs.
Changes in Groundwater Quality
USGS scientists are characterizing groundwater quality in principal aquifers, the primary source of the Nation's groundwater used for drinking. 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.
Follow the links below to learn more about the quality of the Nation’s streams, rivers, and groundwater and how it’s changing.
National Water-Quality Assessment (NAWQA)
Access the data releases and tools relating to water-quality trends below. Explore more data releases on groundwater quality at ScienceBase.
Changes in anthropogenic influences on streams and rivers in the conterminous U.S. over the last 40 years, derived for 16 data themes
The links below provide access to some of the most recent publications describing how the quality of the nation’s surface water and groundwater is changing.
Water-quality trends in US rivers: Exploring effects from streamflow trends and changes in watershed management
Water-quality trends in U.S. rivers, 2002 to 2012: Relations to levels of concern
Modeling drivers of phosphorus loads in Chesapeake Bay tributaries and inferences about long-term change
Increasing chloride in rivers of the conterminous U.S. and linkages to potential corrosivity and lead action level exceedances in drinking water
Water-quality trends in the nation’s rivers and streams, 1972–2012—Data preparation, statistical methods, and trend results
Using groundwater age distributions to understand changes in methyl tert-butyl ether (MtBE) concentrations in ambient groundwater, northeastern United States
Large decadal-scale changes in uranium and bicarbonate in groundwater of the irrigated western U.S
Paleoreconstruction of organic carbon inputs to an oxbow lake in the Mississippi River watershed: Effects of dam construction and land use change on regional inputs
Declining Dioxin concentrations in the Rhone River, France, attest to the effectiveness of emissions controls
U.S. conterminous wall-to-wall anthropogenic land use trends (NWALT), 1974–2012
Effects of urbanization on mercury deposition and accumulation in New England
An overview comparing results from two decades of monitoring for pesticides in the Nation’s streams and rivers, 1992-2001 and 2002-2011
PAH concentrations in lake sediment decline following ban on coal-tar-based pavement sealants in Austin, Texas
Access the data releases and tools relating to water-quality trends below. Explore more data releases on groundwater quality at ScienceBase.
Below are news stories associated with this project.
- Overview
Is water quality getting better or worse? Answering this deceptively simple question has been a fundamental objective of the USGS National Water-Quality Assessment Project’s research. Learn about trends in contaminants in the nation’s streams and rivers, trends in contaminants that collect in the bed sediment of streams and lakes, and changes in the quality of the nation’s groundwater.
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. In response, the NAWQA Project developed multi-pronged approaches to characterize trends in diverse contaminants in the Nation’s streams, rivers, bed sediment, and groundwater.
Trends in Contaminant Concentrations and Loads in the Nation’s Streams and Rivers
The NAWQA Project, other USGS programs, and other Federal, State, and local agencies have collected years of water-quality data to support their assessments of changing water-quality conditions. For the first time, all of these data have been combined to support the most comprehensive assessment conducted to date of water-quality trends in the United States. Collectively, these data provide insight into how natural features and human activities have contributed to water-quality changes over time in Nation's streams and rivers. Data are 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)
Trends in Sediment-Associated Contaminants
Many contaminants adhere, or sorb, to sediment, so that standard water-quality sampling and analysis is often unable to detect changes in their concentrations over time. Sediment-associated contaminants include legacy contaminants, such as DDT and PCBs, and contaminants currently released into the environment, such as the pesticide bifenthrin and polycyclic aromatic hydrocarbons (PAHs). An alternative approach to determine trends in concentrations of these contaminants is the use of sediment cores collected from lakes and reservoirs.
Changes in Groundwater Quality
USGS scientists are characterizing groundwater quality in principal aquifers, the primary source of the Nation's groundwater used for drinking. 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.
- Science
Follow the links below to learn more about the quality of the Nation’s streams, rivers, and groundwater and how it’s changing.
National Water-Quality Assessment (NAWQA)
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. - Data
Access the data releases and tools relating to water-quality trends below. Explore more data releases on groundwater quality at ScienceBase.
Changes in anthropogenic influences on streams and rivers in the conterminous U.S. over the last 40 years, derived for 16 data themes
This product consists of time-series calculations of anthropogenic characteristics derived for 16 data themes for multiple scales covering the conterminous United States. The characteristics are those which (a) have consistent data sources, and (b) have the potential to affect the water quality of streams and rivers. All 16 data themes are provided for Hydrologic Unit Code level-10 (HUC-10) bounda - Publications
The links below provide access to some of the most recent publications describing how the quality of the nation’s surface water and groundwater is changing.
Water-quality trends in US rivers: Exploring effects from streamflow trends and changes in watershed management
We present a conceptual model that explores the relationship of streamflow trends to 15 water-quality parameters at 370 sites across the contiguous United States (US). Our analytical framework uses discrete water-quality data, daily streamflow records, and a statistical model to estimate water-quality trends between 1982 and 2012 and parse these trends into the amount of change attributed to trendAuthorsJennifer C. Murphy, Lori A. SpragueFilter Total Items: 25Water-quality trends in U.S. rivers, 2002 to 2012: Relations to levels of concern
Effective management and protection of water resources relies upon understanding how water-quality conditions are changing over time. Water-quality trends for ammonia, chloride, nitrate, sulfate, total dissolved solids (TDS), total nitrogen (TN) and total phosphorus (TP) were assessed at 762 sites located in the conterminous United States between 2002 and 2012. Annual mean concentrations at the stAuthorsMegan E. Shoda, Lori A. Sprague, Jennifer C. Murphy, Melissa L. RiskinModeling drivers of phosphorus loads in Chesapeake Bay tributaries and inferences about long-term change
Causal attribution of changes in water quality often consists of correlation, qualitative reasoning, listing references to the work of others, or speculation. To better support statements of attribution for water-quality trends, structural equation modeling was used to model the causal factors of total phosphorus loads in the Chesapeake Bay watershed. By transforming, scaling, and standardizing vaAuthorsKaren R. Ryberg, Joel D. Blomquist, Lori A. Sprague, Andrew J. Sekellick, Jennifer L. KeismanIncreasing chloride in rivers of the conterminous U.S. and linkages to potential corrosivity and lead action level exceedances in drinking water
Corrosion in water-distribution systems is a costly problem and controlling corrosion is a primary focus of efforts to reduce lead (Pb) and copper (Cu) in tap water. High chloride concentrations can increase the tendency of water to cause corrosion in distribution systems. The effects of chloride are also expressed in several indices commonly used to describe the potential corrosivity of water, thAuthorsEdward G. Stets, Casey J. Lee, Darren A. Lytle, Michael R. SchockWater-quality trends in the nation’s rivers and streams, 1972–2012—Data preparation, statistical methods, and trend results
Since passage of the Clean Water Act in 1972, Federal, State, and local governments have invested billions of dollars to reduce pollution entering rivers and streams. To understand the return on these investments and to effectively manage and protect the Nation’s water resources in the future, we need to know how and why water quality has been changing over time. As part of the National Water-QualAuthorsGretchen P. Oelsner, Lori A. Sprague, Jennifer C. Murphy, Robert E. Zuellig, Henry M. Johnson, Karen R. Ryberg, James A. Falcone, Edward G. Stets, Aldo V. Vecchia, Melissa L. Riskin, Laura A. De Cicco, Taylor J. Mills, William H. FarmerUsing groundwater age distributions to understand changes in methyl tert-butyl ether (MtBE) concentrations in ambient groundwater, northeastern United States
Temporal changes in methyl tert-butyl ether (MtBE) concentrations in groundwater were evaluated in the northeastern United States, an area of the nation with widespread low-level detections of MtBE based on a national survey of wells selected to represent ambient conditions. MtBE use in the U.S. peaked in 1999 and was largely discontinued by 2007. Six well networks, each representing specific areaAuthorsBruce D. Lindsey, Joseph D. Ayotte, Bryant C. Jurgens, Leslie A. DeSimoneLarge decadal-scale changes in uranium and bicarbonate in groundwater of the irrigated western U.S
Samples collected about one decade apart from 1105 wells from across the U.S. were compiled to assess whether uranium concentrations in the arid climate are linked to changing bicarbonate concentrations in the irrigated western U.S. Uranium concentrations in groundwater were high in the arid climate in the western U.S, where uranium sources are abundant. Sixty-four wells (6%) were above the U.S. EAuthorsKaren R. Burow, Kenneth Belitz, Neil M. Dubrovsky, Bryant C. JurgensPaleoreconstruction of organic carbon inputs to an oxbow lake in the Mississippi River watershed: Effects of dam construction and land use change on regional inputs
We use a dated sediment core from Lake Whittington (USA) in the lower Mississippi River to reconstruct linkages in the carbon cycling and fluvial sediment dynamics over the past 80 years. Organic carbon (OC) sources were characterized using bulk (δ13C, ramped pyrolysis-oxidation (PyrOx) 14C, δ15N, and TN:OC ratios) and compound-specific (lignin phenols and fatty acids, including δ13C and 14C of thAuthorsThomas S. Bianchi, Valier Galy, Brad E. Rosenheim, Michael Shields, Xingquan Cui, Peter C. Van MetreDeclining Dioxin concentrations in the Rhone River, France, attest to the effectiveness of emissions controls
Emission-control policies have been implemented in Europe and North America since the 1990s for polychlorodibenzodioxins (PCDDs) and furans (PCDFs). To assess the effect of these policies on temporal trends and spatial patterns for these compounds in a large European river system, sediment cores were collected in seven depositional areas along the Rhone River in France, dated, and analyzed for PCDAuthorsPeter C. Van Metre, Marc Babut, Brice Mourier, Barbara Mahler, Gwenaelle Roux, Marc DesmetU.S. conterminous wall-to-wall anthropogenic land use trends (NWALT), 1974–2012
This dataset provides a U.S. national 60-meter, 19-class mapping of anthropogenic land uses for five time periods: 1974, 1982, 1992, 2002, and 2012. The 2012 dataset is based on a slightly modified version of the National Land Cover Database 2011 (NLCD 2011) that was recoded to a schema of land uses, and mapped back in time to develop datasets for the four earlier eras. The time periods coincide wAuthorsJames A. FalconeEffects of urbanization on mercury deposition and accumulation in New England
We compare total mercury (HgT) loading and methylmercury (MeHg) accumulation in streams and lakes from an urbanized area (Boston, Massachusetts) to rural regions of southern New Hampshire and Maine. The maximum HgT loading, as indicated by HgT atmospheric deposition, HgT emissions, and sediment HgT concentrations, did not coincide with maximum MeHg concentrations in fish. Urbanized ecosystems wereAuthorsAnn T. Chalmers, David P. Krabbenhoft, Peter C. Van Metre, Mark A. NillesAn overview comparing results from two decades of monitoring for pesticides in the Nation’s streams and rivers, 1992-2001 and 2002-2011
This report provides an overview of the U.S. Geological Survey National Water-Quality Assessment program and National Stream Quality Accounting Network findings for pesticide occurrence in U.S. streams and rivers during 2002–11 and compares them to findings for the previous decade (1992–2001). In addition, pesticide stream concentrations were compared to Human Health Benchmarks (HHBs) and chronicAuthorsWesley W. Stone, Robert J. Gilliom, Jeffrey D. MartinPAH concentrations in lake sediment decline following ban on coal-tar-based pavement sealants in Austin, Texas
Recent studies have concluded that coal-tar-based pavement sealants are a major source of polycyclic aromatic hydrocarbons (PAHs) in urban settings in large parts of the United States. In 2006, Austin, TX, became the first jurisdiction in the U.S. to ban the use of coal-tar sealants. We evaluated the effect of Austin’s ban by analyzing PAHs in sediment cores and bottom-sediment samples collected iAuthorsPeter C. Van Metre, Barbara Mahler - Web Tools
Access the data releases and tools relating to water-quality trends below. Explore more data releases on groundwater quality at ScienceBase.
- News
Below are news stories associated with this project.