Monitored natural attenuation to manage PFAS impacts to groundwater: Potential guidelines

Practical guidelines based on a three-tiered lines of evidence (LOEs) approach have been developed for evaluating monitored natural attenuation (MNA) at per- and polyfluoroalkyl substances (PFAS)-impacted groundwater sites using the scientific basis described in companion paper (Newell et al., 2021). The applies direct measurements indirect measurements, calculations, more complex field modeling methods to assess PFAS retention subsurface. Data requirements LOEs quantifying both vadose saturated zones are identified, as 10 key MNA questions tools that can be applied address them. Finally, list potential enhance is provided where alone may not effectively manage plumes. Overall, practical framework result efficient, reliable management some provided.