Submitted to: North American Benthological Society Bulletin
Publication Type: Proceedings
Publication Acceptance Date: 4/1/2006
Publication Date: 6/1/2006
Citation: Smith, D.R., Warnemuende, E.A., Gillespie, R., Huang, C. 2006. Anthropogenic Contaminants in the Drinking Water Supply for Fort Wayne, Indiana, USA. Bulletin of the North American Benthological Society Bulletin. 23(1):308-309.
Interpretive Summary: The St. Joseph River is the drinking water supply to the 200,000 residents of Ft. Wayne, Indiana. Approximately 281,000 ha of land drains into the St. Joseph river, with approximately 79% of this land being agricultural. Recent studies have shown high levels of atrazine in tap water from Ft. Wayne. The USDA along with collaborators are conducting a study to evaluate the sources of pesticides, nutrients and other contaminants in this drinking water source. In addition to atrazine, nitrates have been found to exceed drinking water standards in tributaries to the St. Joseph River. Glyphosate, commonly referred to as Roundup, is being used by some farmers in the watershed to replace atrazine. From the research data collected, glyphosate concentrations in surface waters collected from the tributaries to the St. Joseph River have not exceeded the drinking water standards. The impact of this research will be to assist in the national evaluation of best management practices to reduce drinking water contamination.
Technical Abstract: The St. Joseph River serves as the drinking water supply to more than 200,000 residents in Ft. Wayne, Indiana and surrounding communities. With a catchment area of 281,000 ha, landuse in the basin is 79% agricultural, and high levels of triazines have been observed in tap water. Currently, tributaries to the St. Joseph River are being investigated to determine the sources of anthropogenic contaminants, and the effectiveness of agricultural conservation practices. Three tile-fed agricultural drainage ditches are being monitored during the growing season for discharge, and nutrient and pesticide concentrations. During storm events, nitrate concentrations in all three ditches have been observed to be greater than the 10 mg/L maximum concentration limit (MCL), and dissolved phosphorus concentrations have been observed to be as great as 6 mg/L. Atrazine concentrations have been observed to be greater than 30 ug/L during spring storm events, which is an order of magnitude greater than the 3 ug/L MCL. Glyphosate concentrations have been much lower than the MCL for drinking water. Ecological data, including quantification of fish species, are currently being collected. Results from this study will aid a national effort to quantify the impacts of agricultural conservation practices on water quality.