Grand Bay National Estuarine Research Reserve has a history of phosphorus (P) contamination because it is located near waste storage mounds of a former fertilizer production facility. Heavy rainfall has caused wastewater to spill over from these mounds and into the waters of Bangs Lake and Bangs Bayou, most notably in 2005 and 2012. This has led to fish die-offs, acidic waters, and algal blooms in these areas. Because P can bind to sediment, when the sediment is disturbed or when water quality changes, P can become suspended in the water and move to different areas long after contamination events. This project focuses on how water, sediment, and P can move throughout these areas, how the amounts of P can change over a period of one year, and how the P amounts in different locations compare to each other. Depth readings, water flow measurements, and water and sediment samples are being taken across these areas. Early results show Bangs Lake having shallow depths and lower flows, while Bangs Bayou is deeper with higher flows. As sampling and analyses continue, this research will give a better understanding of the fate and movement of water, sediment, and P in this estuary.