Clean Water Current

(March 27, 2020) – In a recent report released March 9, NACWA corporate affiliate Arcadis reviewed readily available fate and transport models for groundwater leaching, surface water runoff, and plant uptake as they apply to PFAS in land applied biosolids and residuals. NACWA and the Water Environment Federation (WEF) partnered with the American Forest and Paper Association (AF&PA) and the National Council for Air and Stream Improvement (NCASI) to complete this modeling review.

This report shines greater knowledge on modeling to estimate how PFAS moves through one environmental media to another. Although this report unveiled the fact that there is no one comprehensive model available that can be used to determine PFAS migration for all three fate and transport pathways, there are a few identified models that can be applied to estimate PFAS concentrations in land applied biosolids and residuals moving to groundwater, surface water runoff, and uptake by plants. This report pinpoints several preferred models and, importantly, the limitations of each.

Land application of biosolids containing PFAS continues to be a concern in many states, especially throughout New England. As state regulatory agencies continue their efforts to set aggressive PFAS screening levels or limits for biosolids in some areas, it is key to ensure that the concentration values and/or estimates relied upon are truly reflective of the fate and transport of PFAS in environmental media. Having a robust model that accurately correlates to what is being observed at field sites can help close the gap in what we know about PFAS fate and transport and our ability to estimate PFAS concentrations.   

If members have questions, please contact Emily Remmel, NACWA’s Director of Regulatory Affairs.