RIPARIAN BUFFER EFFECTS ON STREAM CONTAMINATION IN THE CITIES OF MILLERSVILLE AND GOODLETTSVILLE, TENNESSEE

Three of the Cumberland River’s tributaries, Mansker’s Creek, Slater’s Creek, and Lumsley Fork, were placed on the Environmental Protection Agency’s 303(d) list in 2006 due to Escherichia coli (E. coli) measurements above maximum allowable contaminant levels, restricting them from being used for municipal water supply. Urban land use in the impaired streams watersheds ranges from 1.7% to 68.7% of total land use and attributes to many sources of pollution, including storm water runoff, runoff from the improper disposal of trash, septic systems that leak, and animal waste. These issues are exacerbated by impervious surfaces such as driveways, pavement, and rooftops directing water to streams much faster, giving little chance for the water to infiltrate and percolate into the soil. With this water filtering process removed, streams are more reliant on the filtering protection of riparian buffer zones, which are the areas adjacent to streams where vegetation is strongly influenced by the presence of water. Riparian buffers are important for good water quality because they prevent sediment, nitrogen, phosphorus, pesticides, and other pollutants from reaching a stream.

Riparian buffer zone data was obtained for the three contaminated tributaries. Chemical analysis data was also gathered weekly from each of the streams via seven total sample points in 2015. Additionally, property zoning data was obtained for the properties adjacent to the streams, revealing whether the upland properties were residential, agricultural, commercial, or industrial. Analysis of the data revealed that the streams with wider riparian buffers were most effective at filtering nitrates and E. coli in their path to the streams, helping to maintain the overall health of the streams.