Agricultural Contaminants Active
Agriculture: A River Runs Through It
Learn more about interactions between agriculture and water quality
Monitoring Agricultural Runoff
Can farmers keep fertilizer on their fields and out of our rivers and lakes?
Agriculture and the Nation's Water Quality
Informative circulars summarize USGS studies on agricultural activities, water quality, and stream ecology
Stream Health in the Midwest
How intensive agriculture in the Corn Belt affects fish, macroinvertebrates, and algae in small streams
About 40 percent of the land in the United States is used for agriculture, and agriculture supplies a major part of the our food, feed, and fiber needs. Agricultural chemicals move into and through every component of the hydrologic system, including air, soil, soil water, streams, wetlands, and groundwater.
Featured: Nutrient yields in the Mississippi/Atchafalaya River Basin
A new USGS study estimates total nitrogen and phosphorus yields from catchments throughout the Mississippi/Atchafalaya River Basin, which drains about 41% of the conterminous U.S. Agricultural activities were the largest nutrient source.
BACKGROUND
Over the last 100 years, agricultural expansion and intensification has led to changes in water quality and the health of stream ecosystems. Considerable increases in fertilizer and pesticide use began in the 1960s. In 2010, about 11 billion kilograms of nitrogen fertilizer and 300 million kilograms of pesticides were used annually to enhance crop production or control pests. Increased levels of nutrients from fertilizers draining into streams can stimulate algal blooms and affect stream health and recreational uses of local streams, downstream reservoirs, and estuaries, and increase treatment costs for drinking water. Pesticides that are transported to streams can pose risks for aquatic life and fish-eating wildlife and drinking-water supplies.
Find maps, graphs, and data for estimated agricultural use of hundreds of pesticides since 1992.
AGRICULTURAL CONTAMINANTS IN WATER RESOURCES
Agricultural contaminants commonly studied by the USGS include:
- nutrients, such as nitrogen and phosphorus
- pesticides, including herbicides, insecticides, and fungicides
Agricultural contaminants can impair the quality of surface water and groundwater. Fertilizers and pesticides don't remain stationary on the landscape where they are applied; runoff and infiltration transport these contaminants into local streams, rives, and groundwater. Additionally, when land is converted to agricultural use, it is modified to be optimized for agricultural production. Oftentimes these modifications have unintended environmental impacts on receiving waters and their ecosystems, including changes in water quality and quantity. Read about the connections between agriculture and water quality.
Agriculture is the leading source of impairments in the Nation’s rivers and lakes. About a half million tons of pesticides, 12 million tons of nitrogen, and 4 million tons of phosphorus fertilizer are applied annually to crops in the continental United States.1
Pesticides are widespread in surface water and groundwater across the United States. For example, at least one pesticide was found in about 94 percent of water samples and in more than 90 percent of fish samples taken from streams across the Nation, and in nearly 60 percent of shallow wells sampled.2
Transport of excess nutrients is influenced by agricultural practices, such as methods of tillage and drainage, and the timing of application and runoff events like storms and snowmelt. Farmers may leave the soil surface undisturbed from harvest to planting (referred to as “no-till”), and may plant and maintain buffer strips around fields and streams. They may also time fertilizer and manure application to maximize uptake and avoid precipitation events. Use of drip irrigation in lieu of furrow irrigation decreases the amount of water lost to ditches or evaporation, and allows better control of the amounts of pesticides and nutrients added to irrigation water. The USGS studies the amount of nutrients transported off agricultural fields, the effects excess nutrients have on downstream receiving waters, and the effectiveness of on-farm conservations practices that try to reduce the amount of nutrient transport due to runoff. Read about the influence of nutrients on stream ecosystems in agricultural landscapes.
CONFINED ANIMAL FEEDING OPERATION (CAFOs)
Concentrated animal feeding operations (CAFOs) refer to a specific type of animal feeding operation where animals are kept and raised in confined situations for the duration of their lives. Rather than roaming and feeding in a pasture, food is brought to the animals in their pens. Given the cramped conditions, everything is condensed in these facilities, including both live and dead animals, feed, and animal waste. These operations create a significant amount of animal waste which, if released, can greatly affect the environmental. Runoff from these facilities can impair downstream waterways, kill fish, produce harmful algal blooms, and potentially transmit disease. Because of issues that may arise from CAFOs, the USGS works to monitor and quantify potential impacts of these operations to the environment.
AGRICULTURE AND STREAM ECOSYSTEMS
Activities associated with intensive agriculture, such as found in the Midwestern Corn Belt region of the U.S., can change both the water quality and the physical habitat of small streams. In 2013, the USGS intensively monitored 100 small streams in this region, and evaluated the effects of stream "stressors"—including pesticides, nutrients, sedimentation, and riparian disturbance—on stream health. Learn more about the USGS Midwest Stream Quality Assessment and the health of small Midwestern streams here.
RELATED USGS RESEARCH
- Agricultural Chemicals: Where they are, where they’re going, when they create a problem
- Edge-of-field monitoring: Identifying and reducing agricultural sources of excess nutrients
- Veterinary pharmaceuticals in large-scale concentrated animal feeding operations
- Antibiotics in fish aquaculture
ADDITIONAL RESOURCES
U.S. Environmental Protection Agency
U.S. Department of Agriculture
Follow the links below to access web pages describing USGS research on topics related to agriculture and water quality.
Agriculture and the Quality of the Nation's Waters
Follow the links below to data or web applications that explore agricultural practices and their outcomes on rivers and streams.
Follow the links below to recent USGS-authored articles and reports on agricultural chemicals and water quality.
Agriculture — A river runs through it — The connections between agriculture and water quality
Nutrient and pesticide contamination bias estimated from field blanks collected at surface-water sites in U.S. Geological Survey Water-Quality Networks, 2002–12
A hybrid machine learning model to predict and visualize nitrate concentration throughout the Central Valley aquifer, California, USA
Complex mixtures of Pesticides in Midwest U.S. streams indicated by POCIS time-integrating samplers
County-level estimates of nitrogen and phosphorus from animal manure for the conterminous United States, 2007 and 2012
Similarities and differences in occurrence and temporal fluctuations in glyphosate and atrazine in small Midwestern streams (USA) during the 2013 growing season
Prediction and visualization of redox conditions in the groundwater of Central Valley, California
Large decadal-scale changes in uranium and bicarbonate in groundwater of the irrigated western U.S
Statistically extracted fundamental watershed variables for estimating the loads of total nitrogen in small streams
High nitrate concentrations in some Midwest United States streams in 2013 after the 2012 drought
Cyanobacterial harmful algal blooms and U.S. Geological Survey science capabilities
Bifenthrin causes trophic cascades and alters insect emergence in mesocosms: implication for small streams
Contrasting nitrogen fate in watersheds using agricultural and water quality information
Follow the links below to data or web applications that explore agricultural practices and their outcomes on rivers and streams.
There are numerous software packages scientists use to help investigate water quality and pollution transport. Here are a few good examples of applications USGS uses.
See what's newsworthy concerning agricultural contaminants and water quality in the Nation's lakes and rivers.
Massive changes over last 50 years in human influences that affect water quality
Some of the major human influences on water quality, in particular the ways we use land, water, and chemicals, have undergone dramatic changes over the last five decades, according to a new study by the U.S. Geological Survey (USGS) National Water Quality Program. Patterns of urbanization, chemical use, and agricultural production are profoundly altered.
- Overview
About 40 percent of the land in the United States is used for agriculture, and agriculture supplies a major part of the our food, feed, and fiber needs. Agricultural chemicals move into and through every component of the hydrologic system, including air, soil, soil water, streams, wetlands, and groundwater.
Featured: Nutrient yields in the Mississippi/Atchafalaya River BasinA new USGS study estimates total nitrogen and phosphorus yields from catchments throughout the Mississippi/Atchafalaya River Basin, which drains about 41% of the conterminous U.S. Agricultural activities were the largest nutrient source.
BACKGROUND
Over the last 100 years, agricultural expansion and intensification has led to changes in water quality and the health of stream ecosystems. Considerable increases in fertilizer and pesticide use began in the 1960s. In 2010, about 11 billion kilograms of nitrogen fertilizer and 300 million kilograms of pesticides were used annually to enhance crop production or control pests. Increased levels of nutrients from fertilizers draining into streams can stimulate algal blooms and affect stream health and recreational uses of local streams, downstream reservoirs, and estuaries, and increase treatment costs for drinking water. Pesticides that are transported to streams can pose risks for aquatic life and fish-eating wildlife and drinking-water supplies.
Find maps, graphs, and data for estimated agricultural use of hundreds of pesticides since 1992.
AGRICULTURAL CONTAMINANTS IN WATER RESOURCES
Agricultural contaminants commonly studied by the USGS include:
- nutrients, such as nitrogen and phosphorus
- pesticides, including herbicides, insecticides, and fungicides
Agricultural contaminants can impair the quality of surface water and groundwater. Fertilizers and pesticides don't remain stationary on the landscape where they are applied; runoff and infiltration transport these contaminants into local streams, rives, and groundwater. Additionally, when land is converted to agricultural use, it is modified to be optimized for agricultural production. Oftentimes these modifications have unintended environmental impacts on receiving waters and their ecosystems, including changes in water quality and quantity. Read about the connections between agriculture and water quality.
Agriculture is the leading source of impairments in the Nation’s rivers and lakes. About a half million tons of pesticides, 12 million tons of nitrogen, and 4 million tons of phosphorus fertilizer are applied annually to crops in the continental United States.1
Pesticides are widespread in surface water and groundwater across the United States. For example, at least one pesticide was found in about 94 percent of water samples and in more than 90 percent of fish samples taken from streams across the Nation, and in nearly 60 percent of shallow wells sampled.2
Transport of excess nutrients is influenced by agricultural practices, such as methods of tillage and drainage, and the timing of application and runoff events like storms and snowmelt. Farmers may leave the soil surface undisturbed from harvest to planting (referred to as “no-till”), and may plant and maintain buffer strips around fields and streams. They may also time fertilizer and manure application to maximize uptake and avoid precipitation events. Use of drip irrigation in lieu of furrow irrigation decreases the amount of water lost to ditches or evaporation, and allows better control of the amounts of pesticides and nutrients added to irrigation water. The USGS studies the amount of nutrients transported off agricultural fields, the effects excess nutrients have on downstream receiving waters, and the effectiveness of on-farm conservations practices that try to reduce the amount of nutrient transport due to runoff. Read about the influence of nutrients on stream ecosystems in agricultural landscapes.
CONFINED ANIMAL FEEDING OPERATION (CAFOs)
Concentrated animal feeding operations (CAFOs) refer to a specific type of animal feeding operation where animals are kept and raised in confined situations for the duration of their lives. Rather than roaming and feeding in a pasture, food is brought to the animals in their pens. Given the cramped conditions, everything is condensed in these facilities, including both live and dead animals, feed, and animal waste. These operations create a significant amount of animal waste which, if released, can greatly affect the environmental. Runoff from these facilities can impair downstream waterways, kill fish, produce harmful algal blooms, and potentially transmit disease. Because of issues that may arise from CAFOs, the USGS works to monitor and quantify potential impacts of these operations to the environment.
AGRICULTURE AND STREAM ECOSYSTEMS
Activities associated with intensive agriculture, such as found in the Midwestern Corn Belt region of the U.S., can change both the water quality and the physical habitat of small streams. In 2013, the USGS intensively monitored 100 small streams in this region, and evaluated the effects of stream "stressors"—including pesticides, nutrients, sedimentation, and riparian disturbance—on stream health. Learn more about the USGS Midwest Stream Quality Assessment and the health of small Midwestern streams here.
RELATED USGS RESEARCH
- Agricultural Chemicals: Where they are, where they’re going, when they create a problem
- Edge-of-field monitoring: Identifying and reducing agricultural sources of excess nutrients
- Veterinary pharmaceuticals in large-scale concentrated animal feeding operations
- Antibiotics in fish aquaculture
ADDITIONAL RESOURCES
U.S. Environmental Protection Agency
U.S. Department of Agriculture
- Science
Follow the links below to access web pages describing USGS research on topics related to agriculture and water 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. - Data
Follow the links below to data or web applications that explore agricultural practices and their outcomes on rivers and streams.
- Multimedia
- Publications
Follow the links below to recent USGS-authored articles and reports on agricultural chemicals and water quality.
Agriculture — A river runs through it — The connections between agriculture and water quality
Sustaining the quality of the Nation’s water resources and the health of our diverse ecosystems depends on the availability of sound water-resources data and information to develop effective, science-based policies. Effective management of water resources also brings more certainty and efficiency to important economic sectors. Taken together, these actions lead to immediate and longterm economic,AuthorsPaul D. Capel, Kathleen A. McCarthy, Richard H. Coupe, Katia M. Grey, Sheila E. Amenumey, Nancy T. Baker, Richard L. JohnsonFilter Total Items: 48Nutrient and pesticide contamination bias estimated from field blanks collected at surface-water sites in U.S. Geological Survey Water-Quality Networks, 2002–12
Potential contamination bias was estimated for 8 nutrient analytes and 40 pesticides in stream water collected by the U.S. Geological Survey at 147 stream sites from across the United States, and representing a variety of hydrologic conditions and site types, for water years 2002–12. This study updates previous U.S. Geological Survey evaluations of potential contamination bias for nutrients and peAuthorsLaura Medalie, Jeffrey D. MartinA hybrid machine learning model to predict and visualize nitrate concentration throughout the Central Valley aquifer, California, USA
Intense demand for water in the Central Valley of California and related increases in groundwater nitrate concentration threaten the sustainability of the groundwater resource. To assess contamination risk in the region, we developed a hybrid, non-linear, machine learning model within a statistical learning framework to predict nitrate contamination of groundwater to depths of approximately 500 mAuthorsKatherine M. Ransom, Bernard T. Nolan, Jonathan A. Traum, Claudia C. Faunt, Andrew M. Bell, Jo Ann M. Gronberg, David C. Wheeler, Celia Zamora, Bryant C. Jurgens, Gregory E. Schwarz, Kenneth Belitz, Sandra M. Eberts, George Kourakos, Thomas HarterComplex mixtures of Pesticides in Midwest U.S. streams indicated by POCIS time-integrating samplers
The Midwest United States is an intensely agricultural region where pesticides in streams pose risks to aquatic biota, but temporal variability in pesticide concentrations makes characterization of their exposure to organisms challenging. To compensate for the effects of temporal variability, we deployed polar organic chemical integrative samplers (POCIS) in 100 small streams across the Midwest foAuthorsPeter C. Van Metre, David Alvarez, Barbara Mahler, Lisa H. Nowell, Mark W. Sandstrom, Patrick W. MoranCounty-level estimates of nitrogen and phosphorus from animal manure for the conterminous United States, 2007 and 2012
County-level estimates of nitrogen and phosphorus inputs from animal manure for the conterminous United States were calculated from animal population inventories in the 2007 and 2012 Census of Agriculture, using previously published methods. These estimates of non-point nitrogen and phosphorus inputs from animal manure were compiled in support of the U.S. Geological Survey’s National Water-QualityAuthorsJoAnn M. Gronberg, Terri ArnoldSimilarities and differences in occurrence and temporal fluctuations in glyphosate and atrazine in small Midwestern streams (USA) during the 2013 growing season
Glyphosate and atrazine are the most intensively used herbicides in the United States. Although there is abundant spatial and temporal information on atrazine occurrence at regional scales, there are far fewer data for glyphosate, and studies that compare the two herbicides are rare. We investigated temporal patterns in glyphosate and atrazine concentrations measured weekly during the 2013 growingAuthorsBarbara Mahler, Peter C. Van Metre, Thomas E. Burley, Keith A. Loftin, Michael T. Meyer, Lisa H. NowellPrediction and visualization of redox conditions in the groundwater of Central Valley, California
Regional-scale, three-dimensional continuous probability models, were constructed for aspects of redox conditions in the groundwater system of the Central Valley, California. These models yield grids depicting the probability that groundwater in a particular location will have dissolved oxygen (DO) concentrations less than selected threshold values representing anoxic groundwater conditions, or wiAuthorsCelia Z. Rosecrans, Bernard T. Nolan, JoAnn M. GronbergLarge 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. JurgensStatistically extracted fundamental watershed variables for estimating the loads of total nitrogen in small streams
Accurate estimation of total nitrogen loads is essential for evaluating conditions in the aquatic environment. Extrapolation of estimates beyond measured streams will greatly expand our understanding of total nitrogen loading to streams. Recursive partitioning and random forest regression were used to assess 85 geospatial, environmental, and watershed variables across 636 small (<585 km2) watersheAuthorsScott C. Kronholm, Paul D. Capel, Silvia TerziottiHigh nitrate concentrations in some Midwest United States streams in 2013 after the 2012 drought
Nitrogen sources in the Mississippi River basin have been linked to degradation of stream ecology and to Gulf of Mexico hypoxia. In 2013, the USGS and the USEPA characterized water quality stressors and ecological conditions in 100 wadeable streams across the midwestern United States. Wet conditions in 2013 followed a severe drought in 2012, a weather pattern associated with elevated nitrogen concAuthorsPeter C. Van Metre, Jeffrey W. Frey, MaryLynn Musgrove, Naomi Nakagaki, Sharon L. Qi, Barbara Mahler, Michael E. Wieczorek, Daniel T. ButtonCyanobacterial harmful algal blooms and U.S. Geological Survey science capabilities
Cyanobacterial harmful algal blooms (CyanoHABs) are increasingly a global concern because CyanoHABs pose a threat to human and aquatic ecosystem health and cause economic damages. Despite advances in scientific understanding of cyanobacteria and associated compounds, many unanswered questions remain about occurrence, environmental triggers for toxicity, and the ability to predict the timing, duratAuthorsJennifer L. Graham, Neil M. Dubrovsky, Sandra M. EbertsBifenthrin causes trophic cascades and alters insect emergence in mesocosms: implication for small streams
Direct and indirect ecological effects of the widely used insecticide bifenthrin on stream ecosystems are largely unknown. To investigate such effects, a manipulative experiment was conducted in stream mesocosms that were colonized by aquatic insect communities and exposed to bifenthrin-contaminated sediment; implications for natural streams were interpreted through comparison of mesocosm resultsAuthorsHolly Rogers, Travis S. Schmidt, Brittanie L. Dabney, Michelle Hladik, Barbara Mahler, Peter C. Van MetreContrasting nitrogen fate in watersheds using agricultural and water quality information
Surplus nitrogen (N) estimates, principal component analysis (PCA), and end-member mixing analysis (EMMA) were used in a multisite comparison contrasting the fate of N in diverse agricultural watersheds. We applied PCA-EMMA in 10 watersheds located in Indiana, Iowa, Maryland, Nebraska, Mississippi, and Washington ranging in size from 5 to 1254 km2 with four nested watersheds. Watershed Surplus N wAuthorsHedeff I. Essaid, Nancy T. Baker, Kathleen A. McCarthy - Web Tools
Follow the links below to data or web applications that explore agricultural practices and their outcomes on rivers and streams.
- Software
There are numerous software packages scientists use to help investigate water quality and pollution transport. Here are a few good examples of applications USGS uses.
- News
See what's newsworthy concerning agricultural contaminants and water quality in the Nation's lakes and rivers.
Massive changes over last 50 years in human influences that affect water quality
Some of the major human influences on water quality, in particular the ways we use land, water, and chemicals, have undergone dramatic changes over the last five decades, according to a new study by the U.S. Geological Survey (USGS) National Water Quality Program. Patterns of urbanization, chemical use, and agricultural production are profoundly altered.