Syan Smoot is studying the use of drinking water treatment residuals (DWTRs) as a bioretention soil amendment for enhanced phosphorus sorption. DWTRs are the granular material that remains after removing colloidal particles to produce drinkable water. Regulatory entities are concerned that DWTRs may introduce per- and polyfluoroalkyl substances (PFAS) into bioretention effluent when used as a soil amendment. Her project explores whether DWTRs export PFAS through a laboratory column study. Then she will amend a bioretention cell with the best DWTRs from the column study and monitor changes in phosphorus removal.