Removing CECs from Stormwater with Biofiltration

Summary

Biofiltration practices are an urban stormwater treatment practice designed to capture pollutants such as sediment, nutrients, and polycyclic aromatic hydrocarbons (PAHs), among others. The mixed media within biofiltration practices have the potential to also capture, but the effectiveness and best design has yet to be determined. This project is developing new treatment designs that can remove CECs from stormwater runoff. First, researchers evaluate biofiltration by determining the best media components (e.g., compost, biochar, peat, iron, spent lime, etc.) and mix ratios for capturing CECs using outdoor experiments (Activity 1). These experiments optimize the components to balance cost and CEC removal to produce the most cost-effective shovel-ready design. This project also validates the experiments by monitoring CECs in paired inflow (untreated) and outflow (treated by biofiltration media) stormwater samples at several field locations (Activity 2). Through this combined outdoor experiment-scale and field pilot-scale study, guidance will be developed to empower water resource planners and managers with a treatment practice design to remove harmful CECs from stormwater runoff and protect Minnesota's precious water resources.