Onsite wastewater systems (OWS) are a common way of managing wastewater in rural and suburban areas where funding for centralized sewerage is scarce.  However, OWS are increasingly recognized as a potential source of pollutants such as nutrients, pathogens, organic compounds, and metals to groundwater and surface waters. As the human population and generation of wastewater increase, the resiliency of soil-based OWS treatment is being tested more than ever. This session will provide a platform for scientists to showcase their research and share their knowledge on potential dynamics of pollutant transport beneath onsite wastewater systems and potential mitigation strategies.