The objective of this Statement of Need was to improve our understanding of per- and polyfluoroalkyl substances (PFAS) in source zones resulting from the use of aqueous film forming foam (AFFF) formulations by the Department of Defense. In particular, the goal was to better understand the fate of precursor compounds and the role they play in sustaining perfluoroalkyl acid groundwater plumes, as well as the contribution to groundwater contamination of residual PFAS mass in near surface soils. Ultimately, the ability to better characterize and model the nature of sources (and associated plumes) should have led to more targeted remediation strategies based on prioritizing areas posing the greatest risk.

Specific objectives included:

1. Increase understanding of the key characteristics of AFFF source zone areas (vadose zones and/or saturated zone source areas) that affect the risk that PFASs pose to groundwater quality.
2. Development of tools and methods to better characterize the key source zone properties.
3. Investigate the nature and permanence of PFAS retardation mechanisms, and the potential use of these mechanisms in natural or enhanced attenuation.
4. Fill key data gaps regarding the biotransformation and transport of PFAS in AFFF source zones.
5. Develop analytical or mathematical tools to predict the fate and impacts of PFAS in source zones and the potential for continuing releases to groundwater plumes.

Proposals may address one or more of the objectives listed above; however, all proposals must demonstrate how the proposed research will ultimately be used to improve management of PFAS- contaminated sites. Research and development activities at laboratory-, bench-, and field-scale will be considered. Work does not necessarily have to culminate in a field-scale effort.

Funded projects will appear below as project overviews are posted to the website.