Pesticides and Water Quality Active
Pesticides are chemicals designed to kill pests, including insects (insecticides), weeds (herbicides), and fungi (fungicides). The USGS assesses the occurrence and behavior of pesticides in streams, lakes, and groundwater and the potential for pesticides to contaminate our drinking-water supplies or harm aquatic ecosystems.
NOTICE: The USGS agricultural pesticide-use estimates are supported by funding from the USGS National Water Quality Program for the purpose of better understanding pesticides in freshwater and their impact on water availability nationwide. The USGS recently updated its plan to publish pesticide-use estimates. Final annual pesticide-use estimates, for approximately 400 compounds, from 2018-22 will be published in 2025. After that, preliminary estimates will be published annually and later updated with final estimates once the USDA Census of Agriculture is released (every five years). The total number of pesticides included in the analysis will fluctuate annually, based on data availability from our pesticide use survey contract provider. (Updated February 27, 2024)
Pesticides are used in agriculture, in homes and businesses, on lawns and gardens, along roads, in recreational areas, and on pets and livestock. There are hundreds of different pesticide chemicals in use in the United States. In 2007, about 390 million kilograms (430,000 tons) of pesticides, including herbicides, insecticides, and fungicides, were used in the United States. Pesticides released into the environment for agricultural and nonagricultural purposes can contaminate surface water and groundwater, which are critical sources of drinking water.
The USGS, through its National Water Quality Program, researches numerous aspects of pesticides and water quality, and has developed maps, graphics, and tools to aid in understanding where pesticides occur, at what concentrations, and potential consequences.
- Pesticide Use: The tables, maps, and graphs provided on this web site provide estimates of agricultural pesticide use in the conterminous United States for hundreds of pesticides.
- Trends in Pesticide Occurrence in Streams: Use the online tool to view a national maps of trends in pesticide concentrations in streams.
- Concentrations of Pesticides in Water of Potential Human-Health Concern: This searchable online database provides Health-Based Screening Levels (HBSLs) for hundreds of chemicals, including pesticides and degradates.
- Pesticide Toxicity to Aquatic Organisms: The Pesticide Toxicity Index (PTI) can be used to assess the potential toxicity of pesticide mixtures in water to freshwater aquatic organisms. Benchmarks also are available for pesticides in sediment.
- Pesticides and Stream Ecology: The Regional Stream Quality Assessment (RSQA) is assessing how chemical stressors, such as pesticides and nutrients, and physical stressors, such as disturbed streambanks and sedimentation, are affecting the aquatic organisms that live in small streams across the United States.
- Pesticides and Lake Sediment: Many pesticides dissolve in water, but some pesticides, like DDT and chlordane, adhere to sediment and persist for years in the bed sediments of stream and lakes, recording the history of contaminant use in watershed.
Learn more about USGS research on pesticides and related water-quality topics at the web pages below.
Below, you'll find links to data sets developed for investigation of pesticides.
Below, you’ll find the latest in peer-reviewed journal articles and USGS reports on pesticides and water quality. For more publications on this topic, search the USGS Publications Warehouse.
Development and application of a regression equation for estimating the occurrence of atrazine in shallow ground water beneath agricultural areas of the United States
Health-Based Screening Levels and their Application to Water-Quality Data
Evaluation of unsaturated-zone solute-transport models for studies of agricultural chemicals
Estimation of agricultural pesticide use in drainage basins using land cover maps and county pesticide data
Development and Application of Watershed Regressions for Pesticides (WARP) for Estimating Atrazine Concentration Distributions in Streams
Application of health-based screening levels to ground-water quality data in a state-scale pilot effort
Development of health-based screening levels for use in state- or local-scale water-quality assessments
Variability of pesticide detections and concentrations in field replicate water samples collected for the National Water-Quality Assessment Program, 1992-97
Regression models for estimating herbicide concentrations in U.S. streams from watershed characteristics
The National Water-Quality Assessment Program; entering a new decade of investigations
Pesticide toxicity index for freshwater aquatic organisms
Pesticides in the hydrologic system - What do we know and what's next?
Pesticide science in the news! Read recent highlights.
- Overview
Pesticides are chemicals designed to kill pests, including insects (insecticides), weeds (herbicides), and fungi (fungicides). The USGS assesses the occurrence and behavior of pesticides in streams, lakes, and groundwater and the potential for pesticides to contaminate our drinking-water supplies or harm aquatic ecosystems.
NOTICE: The USGS agricultural pesticide-use estimates are supported by funding from the USGS National Water Quality Program for the purpose of better understanding pesticides in freshwater and their impact on water availability nationwide. The USGS recently updated its plan to publish pesticide-use estimates. Final annual pesticide-use estimates, for approximately 400 compounds, from 2018-22 will be published in 2025. After that, preliminary estimates will be published annually and later updated with final estimates once the USDA Census of Agriculture is released (every five years). The total number of pesticides included in the analysis will fluctuate annually, based on data availability from our pesticide use survey contract provider. (Updated February 27, 2024)
Pesticides are used in agriculture, in homes and businesses, on lawns and gardens, along roads, in recreational areas, and on pets and livestock. There are hundreds of different pesticide chemicals in use in the United States. In 2007, about 390 million kilograms (430,000 tons) of pesticides, including herbicides, insecticides, and fungicides, were used in the United States. Pesticides released into the environment for agricultural and nonagricultural purposes can contaminate surface water and groundwater, which are critical sources of drinking water.
The USGS, through its National Water Quality Program, researches numerous aspects of pesticides and water quality, and has developed maps, graphics, and tools to aid in understanding where pesticides occur, at what concentrations, and potential consequences.
- Pesticide Use: The tables, maps, and graphs provided on this web site provide estimates of agricultural pesticide use in the conterminous United States for hundreds of pesticides.
- Trends in Pesticide Occurrence in Streams: Use the online tool to view a national maps of trends in pesticide concentrations in streams.
- Concentrations of Pesticides in Water of Potential Human-Health Concern: This searchable online database provides Health-Based Screening Levels (HBSLs) for hundreds of chemicals, including pesticides and degradates.
- Pesticide Toxicity to Aquatic Organisms: The Pesticide Toxicity Index (PTI) can be used to assess the potential toxicity of pesticide mixtures in water to freshwater aquatic organisms. Benchmarks also are available for pesticides in sediment.
- Pesticides and Stream Ecology: The Regional Stream Quality Assessment (RSQA) is assessing how chemical stressors, such as pesticides and nutrients, and physical stressors, such as disturbed streambanks and sedimentation, are affecting the aquatic organisms that live in small streams across the United States.
- Pesticides and Lake Sediment: Many pesticides dissolve in water, but some pesticides, like DDT and chlordane, adhere to sediment and persist for years in the bed sediments of stream and lakes, recording the history of contaminant use in watershed.
- Science
Learn more about USGS research on pesticides and related water-quality topics at the web pages below.
- Data
Below, you'll find links to data sets developed for investigation of pesticides.
- Publications
Below, you’ll find the latest in peer-reviewed journal articles and USGS reports on pesticides and water quality. For more publications on this topic, search the USGS Publications Warehouse.
Filter Total Items: 116Development and application of a regression equation for estimating the occurrence of atrazine in shallow ground water beneath agricultural areas of the United States
Results from 52 ground-water studies throughout the United States were used to examine relations between the occurrence of atrazine in shallow ground water in agricultural settings and explanatory variables that describe the natural setting, agricultural-management practices, and the type and amount of development in each area. The explanatory variables that were found to be correlated with atraziAuthorsPaul E. Stackelberg, Robert J. Gilliom, David M. Wolock, Kerie J. HittHealth-Based Screening Levels and their Application to Water-Quality Data
To supplement existing Federal drinking-water standards and guidelines, thereby providing a basis for a more comprehensive evaluation of contaminant-occurrence data in a human-health context, USGS began a collaborative project in 1998 with USEPA, the New Jersey Department of Environmental Protection, and the Oregon Health & Science University to calculate non-enforceable health-based screening levAuthorsPatricia L. Toccalino, John S. Zogorski, Julia E. NormanEvaluation of unsaturated-zone solute-transport models for studies of agricultural chemicals
Seven unsaturated-zone solute-transport models were tested with two data sets to select models for use by the Agricultural Chemical Team of the U.S. Geological Survey's National Water-Quality Assessment Program. The data sets were from a bromide tracer test near Merced, California, and an atrazine study in the White River Basin, Indiana. In this study the models are designated either as complex orAuthorsBernard T. Nolan, E. Randall Bayless, Christopher T. Green, Sheena Garg, Frank D. Voss, David C. Lampe, Jack E. Barbash, Paul D. Capel, Barbara A. BekinsEstimation of agricultural pesticide use in drainage basins using land cover maps and county pesticide data
A geographic information system (GIS) was used to estimate agricultural pesticide use in the drainage basins of streams that are studied as part of the U.S. Geological Survey?s National Water-Quality Assessment (NAWQA) Program. Drainage basin pesticide use estimates were computed by intersecting digital maps of drainage basin boundaries with an enhanced version of the National Land Cover Data 1992AuthorsNaomi Nakagaki, David M. WolockDevelopment and Application of Watershed Regressions for Pesticides (WARP) for Estimating Atrazine Concentration Distributions in Streams
Regression models were developed for predicting atrazine concentration distributions in rivers and streams, using the Watershed Regressions for Pesticides (WARP) methodology. Separate regression equations were derived for each of nine percentiles of the annual distribution of atrazine concentrations and for the annual time-weighted mean atrazine concentration. In addition, seasonal models were devAuthorsSteven J. Larson, Charles G. Crawford, Robert J. GilliomApplication of health-based screening levels to ground-water quality data in a state-scale pilot effort
A state-scale pilot effort was conducted to evaluate a Health-Based Screening Level (HBSL) approach developed for communicating findings from the U.S. Geological Survey (USGS) National Water-Quality Assessment Program in a human-health context. Many aquifers sampled by USGS are used as drinking-water sources, and water-quality conditions historically have been assessed by comparing measured contamAuthorsPatricia L. Toccalino, Julia E. Norman, Robyn H. Phillips, Leon J. Kauffman, Paul E. Stackelberg, Lisa H. Nowell, Sandra J. Krietzman, Gloria B. PostDevelopment of health-based screening levels for use in state- or local-scale water-quality assessments
The U.S. Geological Survey (USGS) has a need to communicate the significance of the water-quality findings of its National Water-Quality Assessment (NAWQA) Program in a human-health context. Historically, the USGS has assessed water-quality conditions by comparing water concentration data against established drinking-water standards and guidelines. However, because drinking- water standards andAuthorsPatricia L. Toccalino, Lisa Nowell, William Wilber, John S. Zogorski, Joyce Donohue, Catherine Eiden, Sandra Krietzman, Gloria PostVariability of pesticide detections and concentrations in field replicate water samples collected for the National Water-Quality Assessment Program, 1992-97
Field replicate water samples (“field replicates”) collected for the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program during 1992 to 1997 were used to assess the variability of pesticide detections and concentrations in environmental water samples collected from the surface-and ground-water-quality networks of the NAWQA Program. Field replicates are two or more identicallyAuthorsJeffrey D. MartinRegression models for estimating herbicide concentrations in U.S. streams from watershed characteristics
Regression models were developed for estimating stream concentrations of the herbicides alachlor, atrazine, cyanazine, metolachlor, and trifluralin from use-intensity data and watershed characteristics. Concentrations were determined from samples collected from 45 streams throughout the United States during 1993 to 1995 as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWAuthorsS.J. Larson, R. J. GilliomThe National Water-Quality Assessment Program; entering a new decade of investigations
No abstract available.AuthorsR. J. Gilliom, P. A. Hamilton, T. L. MillerPesticide toxicity index for freshwater aquatic organisms
The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to assess current water-quality conditions, changes in water quality over time, and the effects of natural and human factors on water quality for the Nation's streams and ground-water resources. For streams, one of the most difficult parts of the assessment is to link chemical conditions to effects on aquatiAuthorsMark D. Munn, Robert J. GilliomPesticides in the hydrologic system - What do we know and what's next?
Even though the occurrence and behaviour of pesticides in the environment have been studied for decades, water-quality managers and the public still demand more complete and consistent information, and there are many unanswered questions for environmental scientists. In many respects, the greatest potential for unintended adverse effects of pesticides is through contamination of the hydrologic sysAuthorsR. J. Gilliom - News
Pesticide science in the news! Read recent highlights.