Publication Date

12-1-2006

Degree Program

Department of Geography and Geology

Degree Type

Master of Science

Abstract

Atrazine [2-chloro- 4-(ethylamino)-6-(isopropylamino)-l,3,5-triazine], a widely used herbicide in US corn production, impacts quality of drinking water for many rural water supply systems. Four systems at Rough River Lake, Kentucky, have had high levels of atrazine in raw water and in some cases finished water that have exceeded the legal limit of 3 parts per billion (ppb). The Rough River Lake watershed is 1,700-km2, much of which is located in limestone karst. A hypothesis was developed stating that there would be higher concentrations of atrazine in the northeast section of the Rough River Watershed, located in Hardin County, due to the no-till corn production of the area and karst features. Surface and subsurface samples were collected from eighteen locations (including all major tributaries) within the study area. Sampling began during the Spring of 2005 growing season on a fourteen-day cycle and a twenty-eight day cycle during the fall and winter months. Atrazine concentrations rose at nearly all sites within weeks of the spring application in May, and then began to decrease by late July. Five locations had over 3 ppb for at least two sampling rounds. Two sites exceeded 10 ppb. Global Polynomial Interpolation Analysis was used as both a data exploration tool and a way to demonstrate a definite spatial and temporal pattern to atrazine within the study area. It was also concluded, the reservoir with its larger volume and lower water velocity plays a significant affect on a longer residence time of atrazine, while the tributaries showed lower concentrations of atrazine most likely due to higher velocity and smaller volume of water.

Disciplines

Earth Sciences | Environmental Sciences | Hydrology | Water Resource Management