Examining mycofiltration efficacy in a first-order urban stream: a pilot for future mycelium deployment in Ripplewater Creek, South River Watershed, Atlanta, Georgia

Small-scale surface water restoration methods, such as mycofiltration (the use of fungal mycelium to remove contaminants from the water column), present an affordable remediation alternative to large-scale approaches. This research investigates a green infrastructure remediation technique to mitigate episodic bacterial contamination in first-order urban streams. Bacterial contamination from sanitary and combined sewer overflows, leaking sewer infrastructure, and stormwater runoff decreases urban surface water quality and is exacerbated by the rapid urbanization of Atlanta, Georgia and increasing climate change consequences. Although mycofiltration has been demonstrated to remediate metal contamination, the effectiveness of this method on bacterial contamination mitigation in first-order streams has not been determined. This research will specifically answer the questions (1) How effective is Escherichia coli (E. coli) removal from surface water when interacting with Trametes vericolor fungal spawn for short periods of time? (2) Will statistically significant decreases in E. coli concentrations occur when accounting for hydrologic interactions? and (3) Is the rate of E. coli removal linear or non-linear? This lab-based experiment will utilize a stream table filled with sediment from Ripplewater Creek to simulate a flowing first-order stream. Naturally occurring E. coli from Ripplewater Creek will be isolated, cultured, and routed through a flow rate variable pump with deionized water (1000 MPN/100mL) at a constant rate (3 mL/s) through the stream table for 6 hours. A mycofilter of Trametes vericolor fungal spawn and Quercus alba sawdust trimmings will be deployed at two different sections through the stream table, and samples will be taken and analyzed with an IDEXX Quanti-Tray System hourly in triplicates. This research will potentially inform the future mitigation of E. coli contamination in Ripplewater Creek and the South River watershed based in an environmental justice context. The relative affordability of this remediation method may provide an innovative approach to center community involvement by bridging the gap between policy, neighborhood associations, and local nonprofits.