Overview

The NAWQA Pesticide National Synthesis Project, which began in 1992, is a national-scale assessment of the occurrence and behavior of pesticides in streams and ground water of the United States and the potential for pesticides to adversely affect drinking-water supplies or aquatic ecosystems.

Features

• Prediction of Atrazine Concentrations: Estimate atrazine concentrations in your stream with this interactive model and mapping tool.
  Watershed Regressions for Pesticides (WARP) Atrazine Model (BETA demonstration)
• The Quality of Our Nation's Waters
  Pesticides in the Nation's Streams and Ground Water, 1992-2001
  Released March 2, 2006

• Full Report
• Fact Sheet
• Frequently Asked Questions
• Supporting Information

• Recent Publications

• Comparison of pesticide concentrations in streams at low flow in six metropolitan areas of the United States: Environmental Toxicology and Chemistry, Vol. 27, No. 2, pp. 288–298
  
• Relative toxicity and occurrence patterns of pesticide mixtures in streams draining agricultural watersheds dominated by corn and soybean production: Integrated Environmental Assessment and Management, v.3, n.1, pp. 90-100 (2007)
• Response of stream chemistry during base flow to gradients of urbanization in selected locations across the conterminous United States: USGS SIR 2007-5083 (2007)
• Pesticides in the Nation's Streams and Ground Water; Environmental Science and Technology, v. 41, n.10, pp. 3408–3414 (2007)
• The geochemistry of pesticides. In: Environmental Geochemistry (ed. B. S. Lollar), Volume 9 of Treatise on Geochemistry (eds. H.D.Holland and K.K. Turekian), Elsevier—Pergamon, Oxford, UK, on-line edition, 43 p. (2007)
• How well can we predict the toxicity of pesticide mixtures to aquatic life? Integrated Environmental Assessment and Management, v. 3, n.3, pp. 364-372 (2007)
• Development and application of health-based screening levels for use in water-quality assessments: USGS SIR 2007-5106, 12 p. (2007)

This graph summarizes the availability of  human-health and aquatic-life benchmarks for 330 pesticide active ingredients, including 119 pesticides most commonly analyzed in NAWQA studies.  These benchmarks are used to assess water quality by comparison to concentrations in water. Concentrations greater than a benchmark indicate potential concerns that merit further investigation.  For pesticides without benchmarks, such comparisons cannot be made and potential concerns are unknown.

Benchmarks for human health: The U.S. Environmental Protection Agency (USEPA) has established drinking-water standards or guidelines for 46 of the119 NAWQA pesticides.  USEPA standards (MCLs) are legally enforceable, whereas guidelines (Lifetime Health Advisory and Cancer Risk Concentration values) are not.  To supplement these USEPA benchmarks, USGS collaborated with USEPA and others to develop Health-Based Screening Levels (HBSLs), using USEPA methods and toxicity data.  For the 119 NAWQA pesticides, addition of HBSLs more than doubles the number with benchmarks.

Benchmarks for aquatic life: USEPA has established aquatic-life criteria for 7 of the 119 NAWQA pesticides.  To supplement these benchmarks, USGS collaborated with USEPA to develop additional benchmarks using USEPA methods and toxicity data.  New aquatic-life benchmarks have been completed for 66 NAWQA pesticides, substantially increasing the number with benchmarks. Evaluations are underway for 76 additional pesticides, including 18 NAWQA pesticides.

Posted on April 15, 2008