Per- and polyfluoroalkyl substances (PFAS), once hailed as a “miracle of modern chemistry” has become the menace of the modern century. Initially celebrated for its innumerable applications in consumer products, industrial operations and commercial applications, the connotation of the PFAS classification has evolved into that of the infamous “forever chemical”. However, after decades of on-going pollution of the country’s water resources with insufficient regulatory constraints, water professionals are now faced with the responsibility to react, in lieu of preventative measures. This project was funded by the Department of Defense with the goal of evaluating how effectively a biochar-amended rain garden can remove PFAS from the immediate environment, without significantly depleting its flood control capacities. Stormwater runoff is the primary mode of transport for a vast number of contaminants which degrade the quality of drinking water sources. However, decades of stormwater data collection and analysis from various, on and off-campus stormwater control measures support the claim that rain gardens have an innate ability to naturally treat concentrated influent. This treatment capacity can be enhanced through the application of an adsorptive soil amendment. By applying soil amendments with a higher affinity for PFAS to the topsoil of a rain garden, PFAS can be effectively removed from the immediate environment. The aim of this pilot study is to evaluate the hydrological implications of biochar-amended rain gardens to significantly improve non-point source PFAS removal efficiencies to reduce contamination of drinking water sources within the watershed. Through the enhancement of various biochars and the evaluation of various soil configurations, enhanced PFAS removal rates were achieved with relatively insignificant adverse hydrological implications.
