Download this report as a PDF file (1.83 MB)
Download a free copy of Acrobat Reader
By Elisabeth A. Scribner, E.M. Thurman, Donald A. Goolsby, Michael T. Meyer, William A. Battaglin, and Dana W. Kolpin
Nonpoint-source contamination of water resources from triazine herbicides has been a major water-quality issue during the 1990s in the United States. To address this issue, studies of surface water, ground water, and precipitation have been carried out by the U.S. Geological Survey in the Midwestern United States.
Reconnaissance studies of 147 streams were conducted to determine the geographic and seasonal distribution of atrazine, cyanazine, propazine, and simazine. These studies showed that high concentrations of herbicides were flushed from cropland and transported through the stream system as pulses in response to spring and summer rainfall. The studies also revealed the persistence of herbicides and their degradation products in streams.
An investigation of 76 reservoirs showed that the occurrence and temporal distribution of herbicides and their degradation products in reservoir outflow could be related to reservoir and drainage-basin characteristics, water and land use, herbicide use, and climate. Significant findings showed that concentrations of atrazine and its degradation products remained elevated all summer and into the fall and that recently applied atrazine mixed with atrazine applied the previous year as water moved through a reservoir.
Reconnaissance studies of 303 ground-water wells were completed to determine hydrogeological and seasonal occurrence, concentration, and distribution of herbicides and their degradation products. Samples collected from across the Midwestern United States consistently revealed that triazine herbicide degradation products commonly were found more frequently than their parent herbicide and that ground-water age could be an important factor in explaining variations in herbicide contamination.
A final study investigated precipitation in the Midwestern United States, northeast to the Atlantic Ocean, and northward to the Canadian border. It found that the highest herbicide concentrations in precipitation occurred following herbicide application to cropland. Atrazine was detected most often, followed by deethylatrazine, cyanazine, and deisoproplyatrazine. Mass deposition of herbicides by precipitation was greatest in areas where herbicide use was intense and decreased with distance from the Midwest.
Findings of the 1990s studies include an improved understanding of the occurrence, persistence, chemistry, and transport of triazine herbicides and their degradation products in the hydrologic environment. A significant increase in knowledge of triazine herbicides and development and improvement of analytical methods were accomplished in the past decade. The results produced are not only significant for the present (2005) but provide an important data set for future use.
Scribner, E.A., Thurman, E.M., Goolsby, D.A., Meyer, M.T., Battaglin, W.A., and Kolpin, D.W., 2005, Summary of Significant Results from Studies of Triazine Herbicides and Their Degradation Products in Surface Water, Ground Water, and Precipitation in the Midwestern United States During the 1990s: U.S. Geological Survey Scientific Investigations Report 2005-5094, 27 p.
A limited number of printed copies of the full report are available free from:
U.S. Geological Survey
Kansas Water Science Center
4821 Quail Crest Place
Lawrence, KS 66049
Phone: 785-842-9909
To request a printed copy of this report, email: scribner@usgs.gov
Printed reports also are available for a nominal fee from:
U.S. Geological Survey
Information Services
P.O. Box 25286
Federal Center
Denver, CO 80225
Phone: 1-888-ASK-USGS
NOTE: When ordering the report, please supply the report title and number, your name, and your mailing address. Thank you.
Additional information about triazine herbicides and other research studies can be found at: http://ks.water.usgs.gov/Kansas/researchlab.html
Go to the USGS-Kansas Water Science Center Home Page
| AccessibilityFOIAPrivacyPolicies and Notices | |
  |
|