FY 2023 STATEMENT OF NEED 

Environmental Restoration (ER) Program Area

The objective of this Statement on Need (SON) was to develop an improved understanding of transformation processes for polyfluoroalkyl substances (aka “precursors”) in the subsurface at aqueous film forming foam (AFFF)-impacted sites. Specifically, the goal was to address the following research needs:

• Identify microbiological and/or abiotic processes and pathways capable of either transforming or degrading AFFF-relevant precursors.
• Evaluate relevant environmental factors that affect transformation rates such as subsurface geochemistry, soil chemical/physical properties, nutrient availability, etc.
• Develop methodologies and/or molecular biological tools (MBTs) to assess or predict the extent and rate of in situ transformation under ambient field conditions.

The projects listed below were selected to address the objectives of this SON. Additional information on individual projects can be found by clicking the project title.

• Abiotic and Microbiological Transformation of AFFF-relevant Polyfluoroalkyl Substances
  • Lead Investigator: Feng Xiao, University of Missouri 
• Assessing Polyfluoroalkyl Substance Biotransformation in Soil at AFFF-Impacted Sites
  • Lead Investigator: Dung Nguyen, CDM Smith
• Microbial Attenuation of Polyfluoroalkyl Substances
  • Lead Investigator: Frank Loeffler, University of Tennessee
• Abiotic and Biotic Transformation of PFAS Precursors at Oxic–Anoxic Transition Zones in AFFF-Impacted Soil and Groundwater
  • Lead Investigator: Dengjun Wang, Auburn University
• Environmental Conditions Influencing Natural Abiotic and Biotic Transformation of Perfluoroalkyl Acid Precursors at AFFF-impacted Sites
  • Lead Investigator: Natalie Capiro, Cornell University
• Microbial Transformation of Nitrogen-Containing Precursors and Testing of Molecular Biological Tools with Predictive Potential
  • Lead Investigator: Jinxia Liu, McGill University
• Assessing Polyfluoroalkyl Substances Transformation in Groundwater at AFFF-Impacted Sites Using In Situ Microcosm
  • Lead Investigator: John Xiong, Haley & Aldrich, Inc.
• Abiotic and Coupled Abiotic-Biotic Processes Impacting PFAA Precursor Transformation and Back-Diffusion in Clays
  • Lead Investigator: Charles Schaefer, CDM Smith
• A Systematic Evaluation of Precursor Fate and Transformation in Wetland Systems Across Physical Scales and Biogeochemical Gradients
  • Lead Investigator: Damian Helbling, Cornell University
• Estimation of Biotransformation Rate of Key PFAS Precursors and PFAS Sequestration into Microbial Biomass during Precursor Biotransformation using Activity Based Labeling
  • Lead Investigator: Min-Ying Chu, Haley & Aldrich, Inc.
• Transformation of AFFF Constituents in Enzyme-Catalyzed Oxidative Humification Reactions and Related Fungal Systems
  • Lead Investigator: Qingguo Huang, University of Georgia
• Assessment of Physical, Chemical, and Biological Factors Controlling Biotransformation of Cationic and Zwitterionic Precursors in PFAS Source Zones
  • Lead Investigator: Lisa Alvarez-Cohen, University of California, Berkeley
• Characterization of Fungal Mechanisms to Enhance Biotransformation of Polyfluoroalkyl Substances
  • Lead Investigator: Kent Sorenson, Allonnia

Research should lead to improved risk assessment and site management decisions by providing knowledge of the ubiquity with which transformation processes occur, rates of transformation, how those rates potentially change over time, and the relevant terminal perfluoroalkyl acid (PFAA) transformation products.