UW System Symposium for Undergraduate Research, Scholarly, and Creative Activity

The purpose of this project is to analyze the phosphate trends of Centerville Creek in Southern Manitowoc County. Phosphate, a nutrient ideally found in negligible quantities, exists at unhealthy levels in Centerville Creek due to a variety of causes, many of which are anthropogenic. Sewage, agriculture, and pollution can all contribute to heightened phosphate levels, which can cause harmful Cladophora blooms in rivers and along Lake Michigan's shoreline. Through this research, which involved weekly and rain event sampling of 13 sites along the north and south branches of the creek, it was found that the phosphate trends not only are very high, but also differ depending on which branch the site was on. The southern branch exhibited significantly higher levels of phosphate than the northern branch, contributing to high phosphate levels at the convergence point between the two branches. This observation drives analysis and exploration to examine the causes of these phosphorus levels. The non-point source pattern of contamination indicates that potential sources may be tile line drainage, surface runoff, and in-stream erosion. We also discovered an inverse relationship between the phosphate and turbidity levels, indicating that tile line drainage may be an important contributor. Because Centerville Creek was part of a major restoration project in 2012, this research allows us to assess the success of the restoration efforts, pinpoint nutrient sources, implement methods to decrease these sources, and decrease the harmful side effects of excess phosphorus in our waterways.