Temporal Trends of Selected Agricultural Chemicals in Iowa's Groundwater,
1982-95: Are Things Getting Better?
Dana W. Kolpin, Debra Sneck-Fahrer, George R. Hallberg, and Robert D. Libra
Adapted from original article published in the Journal of Environmental
Quality, v. 26, 1997.
The use of brand names in this paper is for identification purposes
only and does not constitute endorsement by the U.S. Geological
Survey.
- ABSTRACT
- INTRODUCTION
- METHODS
- Field
- Laboratory
- Project Design
- RESULTS
- DISCUSSION
- CONCLUSION
- ACKNOWLEDGMENTS
- REFERENCES
- TABLES
- Table 1. Estimated use of
selected agricultural chemicals in Iowa, 1982-95.
- Table 2. Summary of results for
groundwater samples collected for the Iowa Ground Water Monitoring
Program during the months of April to September (1982-95) for selected
agricultural chemicals.
- Table 3. Temporal patterns in
frequency of detection for selected agricultural chemicals in Iowa
groundwater (1,019 wells). A P value ± 0.05 is not
considered statistically significant.
- Table 4. Temporal patterns in
frequency of detection for selected agricultural chemicals in Iowa
groundwater (1,019 wells) by well depth group.
- Table 5. Temporal patterns in frequency of detection
for selected agricultural chemicals in Iowa groundwater (1,019 wells) by aquifer
type.
- FIGURES (45 K)
- Figure 1. Location of the 1,1019 Iowa municipal
wells used for this study.
- Figure 2. Location of the 89 Iowa municipal
wells having the longest record of agricultural-chemical data available
for this study.
- Figure 3. Statistical summary of the
concentration differential for selected agricultural chemicals.
- Figure 4. Statistical summary of the
concentration differential for selected agricultural chemicals by well
depth.
- Figure 5. Statistical summary of the
concentration differential for selected agricultural chemicals by
aquifer type.
- Figure 6. Summation of alachlor + atrazine +
cyanazine + metolachlor (SUM) for the 89 Iowa municipal wells having
the longest record of agricultural-chemical data available for this
temporal study.
Dana W. Kolpin
dwkolpin@usgs.gov
U.S. Geological Survey,
400 S. Clinton St., Box 1230, Iowa City, IA 52244;
(319)-358-3614 (voice); (319)-358-3606 (fax)
Debra Sneck-Fahrer, U.S. Geological Survey, 400 S. Clinton St.,
Box 1230, Iowa City, IA 52244
George R. Hallberg, University of Iowa Hygienic Laboratory,
102 Oakdale Campus #H101 OH, Iowa City, IA_52242
Robert D. Libra, Iowa Department of Natural Resources,
Geological Survey Bureau, 123 N. Capital, Iowa City, IA 52242
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