WTR Enhanced Aggregate; Sediment Discharge

An increase in urban development was accompanied by an increase in impervious surfaces such as roads, concrete sidewalks, and roofs. This increase in impervious surfaces resulted in an increase of stormwater runoff. Stormwater runoff pollutes freshwater and marine ecosystems. Phosphorus is an especially harmful pollutant within the stormwater, as phosphorus enrichment can lead to eutrophication. Eutrophication is characterized by an increase in algal blooms which eventually result in aquatic plant and animal death. Green stormwater infrastructure, such as rain gardens and detention ponds, are low-cost, low-maintenance solutions for reducing the impact of stormwater runoff. Currently, there is increasing interest in improving the performance of green stormwater infrastructure by amending filtration media with materials that increase their pollutant removal capabilities. Water treatment residuals (WTR), the solids that are left over after the process of drinking water purification, have been shown to increase the efficiency of phosphorus removal when added to filtration media. Here, we introduce WTR-enhanced aggregate; a high-flow filtration media for removing phosphorus from stormwater runoff. The WTR enhanced aggregate consists of WTR bound to gravel via cement. Our current research is focused around proving WTR enhanced aggregate is more effective than gravel at removing phosphorus from stormwater.