The goal of this study was to analyze how concentrations of the pollutant zinc vary across Williamsburg’s Lake Matoaka watershed. At concentrations above a certain threshold, zinc can be toxic to aquatic organisms causing a variety of reproductive, behavioral, and developmental issues. This study looks specifically at the eight main tributaries of the watershed and at the lake itself. For this study, I collected water and sediment samples from the tributaries and the lake and analyzed their zinc concentrations. The results of this analysis show zinc pollution in the Lake Matoaka watershed is significant, with concentrations in the sediment samples of the lake often exceeding the threshold level for toxicity.
Tire-wear and roof particles are major contributors to zinc pollution in the environment, indicating zinc pollution in the watershed is likely caused by runoff from urbanized areas. To study the relationship between zinc concentrations and urbanization, I measured the percent of impervious land in each of the tributary watersheds and compared it to the zinc concentration values. My results show higher concentrations of zinc in the sediment samples from tributaries on the eastern side of the watershed, particularly at the largest tributary in the watershed, College Creek. Many large shopping and residential complexes, as well as William & Mary’s campus, are located on the eastern side. This suggests the high urbanization in the watershed is negatively affecting the water quality in the area. If left unchecked, this will ultimately lead to negative consequences for the aquatic species in the area.
Mattheis, Greta, "Urbanization and Zinc Concentrations in the Lake Matoaka Watershed" (2021). Geology Senior Theses. Paper 10.