As discussed in this topical collection, per- and polyfluoroalkyl substances (PFAS) have recently become a major issue within the water community and for the public at large. Studies have shown the following:
Select PFAS has health consequences at very low concentrations.
Several PFAS have been found in the environment at concentrations that raise concern.
Treatment options for these select PFAS are few, expensive, and have limitations.
Non-targeted analytical approaches continue to identify PFAS in drinking water sources, for which health, fate and transport, and treatment data are lacking.
This juxtaposition of factors combined with a lack of standardized analytical methods, health effects data, and treatment options for the vast majority of PFAS identified in the environment have created a complex regulatory and social dynamic. Without a firm regulatory framework, impacted water utilities and other entities can be pressured into making difficult choices. Ideally, any management approach chosen would be flexible enough to account for future health protection requirements along with changes in other factors, such as increased knowledge of additional PFAS because of advances in analytical techniques or changing influent PFAS concentrations. This flexibility ideally would include both the treatment of the water for its intended use, but also for handling any residual streams that would be disposed of in a managed system or via discharge to the environment. However, any built-in flexibility must be economically, managerially, technically, and environmentally sustainable.
To develop a sound management approach, more guidance is needed. This includes general information to set the stage for what PFAS need to be removed, including
health effects information for all PFAS that have the potential for impacting human health,
ecological impact information to allow for adequate determinations on discharges,
occurrence information for these PFAS to determine relative source contribution, and
PFAS analytical techniques for various relevant matrices.
Furthermore, treatment performance and costs are needed to decide strategies that can economically remove PFAS to levels that will not harm humans or sensitive ecosystems. In lieu of this information, internal and external pressure on a site or community may leave it no choice but to start analyzing for PFAS with current methods and installing treatment for removing these PFAS. Some removal efforts could proceed without a full understanding of the complete suite of PFAS occurrence information and potential health impacts, along with the benefits from the concurrent removal of other contaminants. The research covered within this topical collection includes many of these areas and points to future research directions that can help guide those in decision-making positions.