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
Trends in groundwater quality in principal aquifers of the United States, 1988-2012
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.
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
Trends in groundwater quality in principal aquifers of the United States, 1988-2012
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.