Assessing the Presence and Concentrations of Nutrient Pollution In Freshwater Environments In Fredericksburg, Virginia

By Reagan Nierman

Faculty Mentor: Professor Tyler Frankel

Aquatic environments require nutrients such as phosphorus and nitrogen to function properly and form the base of complex food webs. However, excess inputs of these nutrients through anthropogenic pollution commonly results in algal blooms, hypoxia, and dead zones. In this study, surface water samples were taken from five sites located around the city of Fredericksburg (City Dock, Old Mill, Ficklen Island, Motts Run Reservoir, and Little Falls). Samples were collected weekly between February 17th – March 24h in 1000mL bottles and analyzed for the presence and concentrations of total phosphorus, nitrate, nitrite, copper, and chlorine using colorimetric assays. During the six weeks of sampling no concentrations of nitrite, copper, or chlorine were detected at any location. Nitrate levels fluctuated at each site with levels ranging from 1.0mg/L to 5.0mg/L. Phosphate was observed to be a cause for concern as concentrations were consistently found at 0.4mg/L to 1.0mg/L in all streams. While the sources of these excess nutrients are unclear, possibilities include excess wastewater treatment facility effluent discharge during heavy precipitation events, construction over waterways that loosens sediment and increases runoff events, and proximity to more heavily populated areas. These results suggest the need for a long-term study to assess what influence seasonal temperatures and precipitation have on nutrient pollution and how these excess nutrient levels impact aquatic organisms in these locations.