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Pesticide Contamination of Ground Water Artificially Recharged by Farmland Runoff |
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| Authors: | Mary E Exner |
| Institution: | Mary E. Exner received a B.S. in chemistry from Chestnut Hill College in 1970 and an M.S. in oceanography from Texas A&M University in 1972. Since 1974 she has been with thelnstitute of Agriculture and Natural Resources at the University of Nebraska (Conservation and Survey.Division, 113 Nebraska Halt Institute of Agriculture and Natural Resources) University of Nebraska) Livlcoln) NE 68588451 7). Her research interests are in the area of ground water hydrochemistry. |
| Abstract: | Atrazine, cyanazine, alachlor, and metolachlor in the surface water of a recharge structure, which impounds runoff from row-cropped farmland in Nebraska, are transported with seepage to the shallow ground water flow system and to the locally confined regional aquifer. All wells in the shallow flow system and all those in the regional flow system impacted by seepage from the structure had detectable concentrations of at least one of the four pesticides. The detectable concentrations of cyanzine, alachlor, and metolachlor in the two flow systems ranged from 0.1 to 0.9 ppb. These concentrations were an order of magnitude lower than those in the surface water. Concentrations in the regional aquifer clustered at the lower end of this concentration range. These three pesticides were not detected in the baseline study of the regional aquifer. Unlike alachlor, cyanzine, and metolachlor, atrazine was always present in the wells impacted by seepage from the recharge structure. In the shallow flow system, concentrations ranged from 0.3 to 8.8 ppb and from 0.1 to 2.5 ppb in the regional aquifer. The average of the detectable atrazine concentrations in the baseline study was 0.04 ± 0.05 ppb. |
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