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.
Quality-control design for surface-water sampling in the National Water-Quality Assessment Program
Classification and Mapping of Agricultural Land for National Water-Quality Assessment
Analysis of environmental data with censored observations
Occurrence of selected herbicides and herbicide degradation products in Iowa's Ground Water, 1995
Temporal trends of selected agricultural chemicals in Iowa's groundwater, 1982-1995: Are things getting better?
Pesticides in ground water: distribution, trends, and governing factors
Evaluation of selected information on splitting devices for water samples
Pesticides in ground water: Current understanding of distribution and major influences
Pesticides in the atmosphere: distribution, trends, and governing factors
Acetochlor in the hydrologic system in the midwestern United States, 1994
Design of the National Water-Quality Assessment Program; occurrence and distribution of water-quality conditions
Pesticides in the atmosphere–Current understanding of distribution and major influences
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: 116Quality-control design for surface-water sampling in the National Water-Quality Assessment Program
The data-quality objectives of the National Water-Quality Assessment Program include estimating the extent to which contamination, matrix effects, and measurement variability affect interpretation of chemical analyses of surface-water samples. The quality-control samples used to make these estimates include field blanks, field matrix spikes, and replicates. This report describes the design for colAuthorsDavid K. Mueller, Jeffrey D. Martin, Thomas J. LopesClassification and Mapping of Agricultural Land for National Water-Quality Assessment
Agricultural land use is one of the most important influences on water quality at national and regional scales. Although there is great diversity in the character of agricultural land, variations follow regional patterns that are influenced by environmental setting and economics. These regional patterns can be characterized by the distribution of crops. A new approach to classifying and mapping agAuthorsRobert J. Gilliom, Gail P. ThelinAnalysis of environmental data with censored observations
The potential threats to humans and to terrestrial and aquatic ecosystems from environmental contamination could depend on the sum of the concentrations of different chemicals. However, direct summation of environmental data is not generally feasible because it is common for some chemical concentrations to be recorded as being below the analytical reporting limit. This creates special problems inAuthorsS. Liu, J.-C. Lu, D.W. Kolpin, W.Q. MeekerOccurrence of selected herbicides and herbicide degradation products in Iowa's Ground Water, 1995
Herbicide compounds were prevalent in ground water across Iowa, being detected in 70% of the 106 municipal wells sampled during the summer of 1995. Herbicide degradation products were three of the four most frequently detected compounds for this study. The degradation product alachlor ethanesulfonic acid was the most frequently detected compound (65.1%), followed by atrazine (40.6%), and the degraAuthorsD.W. Kolpin, S. J. Kalkhoff, D. A. Goolsby, D. A. Sneck-Fahrer, E. M. ThurmanTemporal trends of selected agricultural chemicals in Iowa's groundwater, 1982-1995: Are things getting better?
Since 1982, the Iowa Groundwater Monitoring (IGWM) Program has been used to sample untreated groundwater from Iowa municipal wells for selected agricultural chemicals. This long-term database was used to determine if concentrations of select agricultural chemicals in groundwater have changed with time. Nitrate, alachlor [2-chloro-2′-6′-diethyl-N-(methoxymethyl)-acetanilide], atrazine (2-chloro-4-eAuthorsD.W. Kolpin, D. Sneck-Fahrer, G.R. Hallberg, R.D. LibraPesticides in ground water: distribution, trends, and governing factors
A comprehensive review of published information on the distribution and behavior of pesticides and their transformation products in ground water indicates that pesticides from every chemical class have been detected in ground waters of the United States. Many of these compounds are commonly present at low concentrations in ground water beneath agricultural land. Little information is available onAuthorsJack Barbash, Elizabeth A. ResekEvaluation of selected information on splitting devices for water samples
Four devices for splitting water samples into representative aliquots are used by the U.S. Geological Survey's Water Resources Division. A thorough evaluation of these devices (14-liter churn, 8-liter churn, plastic cone, and Teflon cone) encompasses a wide variety of concerns, based on both chemical and physical considerations. This report surveys the existing data (as of April 1994) on cleaningAuthorsP. D. Capel, S.J. LarsonPesticides in ground water: Current understanding of distribution and major influences
This report summarizes a comprehensive analysis of existing information on national and regional patterns of pesticides in the atmosphere and major influences on their sources and transport. It is one of a four-part series that synthesizes current knowledge and understanding of pesticides in water resources of the nation as part of the National Water-Quality Assessment.AuthorsPesticides in the atmosphere: distribution, trends, and governing factors
Most people know about the presence and health effects of pesticide residues in the water they drink. However, they may not realize the impact of atmospheric transportation and deposition of pesticides on water quality. Scientific studies of pesticides in various atmospheric matrices (air, rain, snow, aerosols, and fog) provide some of the answers. Pesticides in the Atmosphere focuses on the revieAuthorsMichael S. Majewski, Paul D. CapelAcetochlor in the hydrologic system in the midwestern United States, 1994
The herbicide acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)acetamide] was given conditional registration in the United States by the U.S. Environmental Protection Agency in March 1994. This registration provided a rare opportunity to investigate the occurrence of a pesticide during its first season of extensive use in the midwestern United States. Water samples collected and anaAuthorsD.W. Kolpin, B.K. Nations, D. A. Goolsby, E. M. ThurmanDesign of the National Water-Quality Assessment Program; occurrence and distribution of water-quality conditions
The National Water-Quality Assessment Program assesses the status of and trends in the quality of the Nation's ground- and surface-water resources. The occurrence and distribution assessment component characterizes broad-scale water-quality conditions in relation to major contaminant sources and background conditions in each study area. The surface-water design focuses on streams. The ground-waterAuthorsRobert J. Gilliom, William M. Alley, Martin E. GurtzPesticides in the atmosphere–Current understanding of distribution and major influences
This report summarizes a comprehensive analysis of existing information on national and regional patterns of pesticides in the atmosphere and major influences on their sources and transport. It is one of a four-part series that synthesizes current knowledge and understanding of pesticides in water resources of the nation as part of the National Water-Quality Assessment.Authors - News
Pesticide science in the news! Read recent highlights.