 | The 131st Annual Meeting (November 15-19, 2003) of APHA |
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| The 131st Annual Meeting (November 15-19, 2003) of APHA |
Aaron Kite-Powell and Anna K. Harding, PhD. Department of Public Health, Oregon State University, 264 Waldo Hall, Corvallis, OR 97331, 541-737-1281, kitepowa@onid.orst.edu
Abstract: The contamination of groundwater in agricultural areas with nitrate and pesticides is increasingly of concern throughout the United States, and in certain geographical regions in Oregon. The purpose of this study was to determine the extent of well water contamination with nitrate and pesticides, and to understand the relationships among nitrate, pesticide, dissolved chloride, and well depth in the southern Willamette Valley, Oregon, and to investigate local residents’ perceptions and opinions regarding water quality issues. The Oregon Department of Environmental Quality (ODEQ) analyzed samples, collected by judgment sampling, of untreated well water from 486 households throughout the southern Willamette Valley for nitrate contamination in the winter of 2000-2001. A 100 household subset of the original 486 households were re-sampled in the summer of 2002 to be tested again for nitrate and further analyzed for pesticides, and dissolved chloride. Preliminary results show that 7.4% of the samples exceed national standard of 10 mg/l nitrate-N. A Spearman rank-order correlation demonstrated that as nitrate-N levels decrease the well depth increases (rs = -.26, p < .001). Households having had two nitrate tests, separated by a year and a half, were found to have significantly higher nitrate levels for the second test date, demonstrated by Wilcoxon rank sum test; N=90, (64 positive differences and 26 negative differences) t = -4.4, p < .001. The presentation will also include additional results from a survey designed to assess the perceptions and opinions of local residents regarding land use activities and water quality issues.
Learning Objectives:
Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.