Files
Abstract
The Lake Allyn M. Herrick watershed is about 131 ha and covers portions of the University of Georgias East campus, the Oconee Forest and residential and commercial land use. Lake Herrick, a 6-ha water body established in 1982 on the University of Georgia campus, was closed in 2002 for recreation due to fecal contamination. Subsequent monitoring confirmed cyanobacterium blooms on the surface of the lake and elevated nutrient concentrations, especially phosphorus. Previous studies showed that phosphorus and fecal coliform were the main contaminants. In our study, two inflow tributaries (sites Birdsong and Armadillo) and the outlet stream (site Below Dam) were monitored for discharge, E. coli, forms of nitrogen and phosphorus, and other water quality parameters during baseflow and storm conditions from February 2016 to October 2017. Our results showed that total phosphorus was significantly higher during stormflow compared to baseflow and total nitrogen remained the same. E. coli results indicated that most of the bacteria entered the lake through the tributaries during stormflow. Microbial source tracking methods were used to detect the bacterial source in the samples specific to a dog, ruminant or human host. We found that dogs are a more likely source of this bacteria than humans or deer. The fact that human sources were uncommon in the Lake Herrick watershed indicated that there was reduced risk for human source contamination. Lake Herrick was reopened for limited recreation in October 2018.