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
Linking the agricultural landscape of the Midwest to stream health with structural equation modeling
Understanding the influence of nutrients on stream ecosystems in agricultural landscapes
Relative importance of water-quality stressors in predicting fish community responses in midwestern streams
The Midwest Stream Quality Assessment—Influences of human activities on streams
Modeling drivers of phosphorus loads in Chesapeake Bay tributaries and inferences about long-term change
Assessing the influence of multiple stressors on stream diatom metrics in the upper Midwest, USA
A conceptual framework for effectively anticipating water-quality changes resulting from changes in agricultural activities
Influence of sediment chemistry and sediment toxicity on macroinvertebrate communities across 99 wadable streams of the Midwestern USA
Complex mixtures of dissolved pesticides show potential aquatic toxicity in a synoptic study of Midwestern U.S. streams
Multistressor predictive models of invertebrate condition in the Corn Belt, USA
Holistic assessment of occurrence and fate of metolachlor within environmental compartments of agricultural watersheds
A field study of selected U.S. Geological Survey analytical methods for measuring pesticides in filtered stream water, June - September 2012
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: 48Linking the agricultural landscape of the Midwest to stream health with structural equation modeling
Multiple physical and chemical stressors can simultaneously affect the biological condition of streams. To better understand the complex interactions of land-use practices, water quality, and ecological integrity of streams, the U.S. Geological Survey National Water Quality Assessment Project is conducting regional-scale assessments of stream condition across the United States. In the summer of 20AuthorsTravis S. Schmidt, Peter C. Van Metre, Daren CarlisleUnderstanding the influence of nutrients on stream ecosystems in agricultural landscapes
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 long-term economic,AuthorsMark D. Munn, Jeffrey W. Frey, Anthony J. Tesoriero, Robert W. Black, John H. Duff, Kathy Lee, Terry R. Maret, Christopher A. Mebane, Ian R. Waite, Ronald B. ZeltRelative importance of water-quality stressors in predicting fish community responses in midwestern streams
Fish, habitat, and water chemistry data were collected from 98 streams in the midwestern United States, an area dominated by intense cultivation of row crops, in order to identify important water‐quality stressors to fish communities. We focused on 10 stressors including riparian disturbance, riparian vegetative cover, instream fish cover, streambed sedimentation, streamflow variability, total nitAuthorsMichael R. Meador, Jeffrey W. FreyThe Midwest Stream Quality Assessment—Influences of human activities on streams
Healthy streams and the fish and other organisms that live in them contribute to our quality of life. Extensive modification of the landscape in the Midwestern United States, however, has profoundly affected the condition of streams. Row crops and pavement have replaced grasslands and woodlands, streams have been straightened, and wetlands and fields have been drained. Runoff from agricultural andAuthorsPeter C. Van Metre, Barbara Mahler, Daren Carlisle, James F. ColesModeling 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. KeismanAssessing the influence of multiple stressors on stream diatom metrics in the upper Midwest, USA
Water resource managers face increasing challenges in identifying what physical and chemical stressors are responsible for the alteration of biological conditions in streams. The objective of this study was to assess the comparative influence of multiple stressors on benthic diatoms at 98 sites that spanned a range of stressors in an agriculturally dominated region in the upper Midwest, USA. The pAuthorsMark D. Munn, Ian R. Waite, Christopher P. KonradA conceptual framework for effectively anticipating water-quality changes resulting from changes in agricultural activities
Agricultural activities can affect water quality and the health of aquatic ecosystems; many water-quality issues originate with the movement of water, agricultural chemicals, and eroded soil from agricultural areas to streams and groundwater. Most agricultural activities are designed to sustain or increase crop production, while some are designed to protect soil and water resources. Numerous soil-AuthorsPaul D. Capel, David M. Wolock, Richard H. Coupe, Jason L. RothInfluence of sediment chemistry and sediment toxicity on macroinvertebrate communities across 99 wadable streams of the Midwestern USA
Simultaneous assessment of sediment chemistry, sediment toxicity, and macroinvertebrate communities can provide multiple lines of evidence when investigating relations between sediment contaminants and ecological degradation. These three measures were evaluated at 99 wadable stream sites across 11 states in the Midwestern United States during the summer of 2013 to assess sediment pollution acrossAuthorsPatrick W. Moran, Lisa H. Nowell, Nile E. Kemble, Barbara Mahler, Ian R. Waite, Peter C. Van MetreComplex mixtures of dissolved pesticides show potential aquatic toxicity in a synoptic study of Midwestern U.S. streams
Aquatic organisms in streams are exposed to pesticide mixtures that vary in composition over time in response to changes in flow conditions, pesticide inputs to the stream, and pesticide fate and degradation within the stream. To characterize mixtures of dissolved-phase pesticides and degradates in Midwestern streams, a synoptic study was conducted at 100 streams during May–August 2013. In weeklyAuthorsLisa H. Nowell, Patrick W. Moran, Travis S. Schmidt, Julia E. Norman, Naomi Nakagaki, Megan E. Shoda, Barbara Mahler, Peter C. Van Metre, Wesley W. Stone, Mark W. Sandstrom, Michelle L. HladikMultistressor predictive models of invertebrate condition in the Corn Belt, USA
Understanding the complex relations between multiple environmental stressors and ecological conditions in streams can help guide resource-management decisions. During 14 weeks in spring/summer 2013, personnel from the US Geological Survey and the US Environmental Protection Agency sampled 98 wadeable streams across the Midwest Corn Belt region of the USA for water and sediment quality, physical anAuthorsIan R. Waite, Peter C. Van MetreHolistic assessment of occurrence and fate of metolachlor within environmental compartments of agricultural watersheds
Background: Metolachlor [(RS)-2-Chloro-N-(2-ethyl-6-methyl-phenyl)-N-(1-methoxypropan-2-yl)acetamide] and two degradates (metolachlor ethane-sulfonic acid and metolachlor oxanilic acid) are commonly observed in surface and groundwater. The behavior and fate of these compounds were examined over a 12-year period in seven agricultural watersheds in the United States. They were quantified in air, raiAuthorsClaire E. Rose, Richard H. Coupe, Paul D. Capel, Richard M. WebbA field study of selected U.S. Geological Survey analytical methods for measuring pesticides in filtered stream water, June - September 2012
U.S. Geological Survey monitoring programs extensively used two analytical methods, gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry, to measure pesticides in filtered water samples during 1992–2012. In October 2012, the monitoring programs began using direct aqueous-injection liquid chromatography tandem mass spectrometry as a new analytical method for pesticides.AuthorsJeffrey D. Martin, Julia E. Norman, Mark W. Sandstrom, Claire E. Rose - 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.