WATER QUALITY IN THE WOLF RUN BASIN, LEXINGTON, KENTUCKY

Part of the University of Kentucky’s (UK’s) campus is located in the Wolf Run basin, which drains much of downtown Lexington. Several types of pollutants impact the basin’s water quality, including enteric bacteria and other microorganisms, sediment, nutrients, and various other chemicals such as hydrocarbons, metals, and salts. Both point source leakage (e.g. underground pipes) and storm-induced runoff from lawns and pavements contribute these pollutants to the basin. The goal of this study was to monitor the levels of these pollutants within the basin to understand how their levels change within the basin and over a period of time.

From January 29 to April 23, 2015, we collected weekly to biweekly samples from the inlet to the rain garden behind the Gluck Equine Center (a constructed wetland) and the Blue Hole at McConnell Springs (which is near the outlet of the basin). We measured air temperature, water temperature, pH, specific conductance (SC, a measure of salinity), and dissolved oxygen (DO). We collected samples for total coliform bacteria, Escherichia coli (E. coli), anions, and metals.

Results are consistent with the different locations of the sampling sites within the basin. McConnell Springs drains most of the basin, while the rain garden only receives flow from part of UK’s campus. The values for water temperature, pH, SC, and DO were more stable over time for the Blue Hole than for the rain garden, which is consistent with the different locations of the sampling sites within the basin. The Blue Hole’s flow was larger and therefore influenced to a lesser extent by the most recent runoff. SC increased in winter at the same time Na⁺ and Cl^- ions did, which is consistent with inputs of road salt from melting snow. Values of DO generally increased as water temperature decreased, as should be expected. Counts of total coliform and E. coli bacteria were much higher in the Blue Hole than in the rain garden except for March 26. This indicates that the Blue Hole receives more leakage from sanitary sewers and/or fecal matter from animals in the basin. The spike in bacterial counts at the rain garden on March 26 may be related to fecal matter from the local goose population.