Per-and polyfluoroalkyl substances (PFAS) groundwater plumes present new and significant challenges to site owners, consultants, and regulators because of the potentially large number of sites, low degradability, ineffectiveness of many in-situ remediation technologies, and very low action levels. Retention-based PFAS Monitored Natural Attenuation (MNA) may be useful for understanding which plumes should be managed immediately with pump and treat systems and which plumes might be managed in the near term by MNA or Enhanced Attenuation (EA). The philosophy and the scientific basis of PFAS MNA and EA will be discussed by reviewing retention-based MNA analogs with other contaminants and key PFAS retention processes such as air/water interfacial sorption and matrix diffusion.
Dr. Charles Newell is a Vice President of GSI Environmental Inc. He is a member of the American Academy of Environmental Engineers, a NGWA Certified Ground Water Professional, and an Adjunct Professor at Rice University. He was awarded the ITRC Environmental Excellence Award in 2016 and the 2020 Foundation Achievement Award presented by the Association for Environmental Health and Science.