Groundwater and PFAs: State of Knowledge and Practice

National Ground Water Association (NGWA) Press, Westerville, OH. ISBN: 1-56034-037-1, 114 pp, 2017

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a group of chemicals that are emerging contaminants of concern due to their persistence in the environment, bioaccumulative potential, and toxicity.

Chemical structure of perfluorooctanoic acid

PFASs have previously been used in a range of industrial processes, consumer products (such as 3M’s Scotchgard fabric and upholstery protector), aviation hydraulic fluid and fire-fighting foam. The two main PFASs are perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). The unique properties of PFASs that make them useful in products and industrial processes also mean that they are persistent in the environment and highly mobile. They are therefore challenging to manage and remediate once released into the environment. They are potentially bioaccumulative and potential health effects may include developmental, reproductive and systemic effects and possibly cancer. PFOS has been listed as a persistent organic pollutant (POP) in Annex B of the Stockholm Convention since 2010. The use of PFOS in products has been phased out in Australia since the early 2000’s.

Beginning in October 2016, 37 scientists and engineers voluntarily collaborated through the National Ground Water Association to develop information on per- and polyfluoroalkyl substances (PFASs) for the broader groundwater community. Using a consensus-driven process that included a public comment period, their efforts were completed toward the end of 2017.  NGWA published this PFAS document to assist members and other groundwater professionals who may be tasked with investigating the transport pathways and extent of PFASs in groundwater and surface water, assessing potential risks to receptors, or designing and constructing engineering controls to manage subsurface PFAS contamination.  The main purpose of this document is to summarize the current state of knowledge and practice regarding PFAS fate, transport, remediation, and treatment, recognizing that knowledge in this field continues to advance. This document also summarizes current technologies, methods, and field procedures being used to characterize sites and test remediation and treatment technologies. Temporarily available at

PFAs can be used in fire fighting foams