“Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic Acid (PFOA): Department of Defense Policy and Management Issues" by Ms. Maureen Sullivan 

The use of Aqueous Film-Forming Foam (AFFF) formulations has resulted in the introduction of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) into soils and groundwater on DoD sites. PFOS and PFOA are stable in the environment and often form large groundwater plumes. The regulatory requirements for these contaminated soils and groundwaters are still evolving, with the current drinking water Health Advisory Levels (HALs) relatively low (70 ng/L total PFOS and PFOA). These compounds also are resistant to common treatment technologies, so remediation generally requires ex situ treatment and generates waste for off-site destruction or disposal. DoD has begun an aggressive effort to characterize and ultimately remediate its PFOS and PFOA-impacted sites. DoD is currently performing initial site investigations at nearly all DoD facilities in the United States to determine the extent of contamination. It is anticipated that Remedial Investigations (RIs) will begin at many DoD sites in the next few years. Through organizations like SERDP and ESTCP, DoD has also funded research on AFFF contamination to improve analytical methods, understand ecotoxicological effects, develop tools for assessing the fate of PFOS and PFOA in the subsurface, and evaluate potential remediation technologies. Reducing the potential magnitude of the DoD’s PFOS and PFOA liability will require a sustained effort to identify best available technologies and management tools.

"SERDP & ESTCP Efforts to Gain a Better Understanding of Issues Associated with Per- and Polyfluoroalkyl Substances in the Subsurface" by Dr. Andrea Leeson

Although DoD has taken steps to address per- and polyfluoroalkyl substance (PFAS) contamination in the environment, scientific understanding of PFASs is still in an early stage of development with significant uncertainties. Efforts to develop a better understanding of issues associated with PFASs were initiated under SERDP in 2011. Following up on this work, an expert workshop was convened in May 2017 to provide strategic guidance on topics for PFAS-related research, demonstrations and technology transfer. Workshop objectives were as follows: (1) to review the current state of the science regarding sources of PFAS contamination, particularly AFFF, (2) to evaluate current and potential characterization and remediation technologies, and (3) to identify research and demonstration opportunities to improve remediation performance, efficiency, and ultimately reduce site management costs. The workshop was attended by approximately 60 invited personnel, representing DoD remediation program managers, federal and state regulators, engineers, researchers, industry representatives, and consultants. Workshop participants prepared a report that identified and prioritized several promising research and development needs, demonstration topics, and technology transfer opportunities. Recommendations from this workshop will require several years of intensive work, with careful thought to the sequencing of R&D efforts. However, given the magnitude of the potential problems associated with PFAS contamination at DoD sites and the high costs of investigations and remediation, the return on investments in R&D in this area are likely to be significant.

"Fighting the Unbeatable Foe: Remediation of Groundwater Contaminated by PFAS with In Situ Chemical Oxidation" by Dr. David Sedlak

The use of AFFF has led to contamination of groundwater with PFAS.  In situ chemical oxidation (ISCO) has the potential to be a cost-effective remediation strategy.  To assess the potential for employing ISCO with hydrogen peroxide or activated persulfate for groundwater remediation, laboratory experiments were performed with AFFF and its individual components.  Both oxidants oxidized polyfluoroalkyl substances under conditions typically employed during ISCO.  The main perfluoroalkyl substance in fluorotelomer-based AFFF, 6:2 fluorotelomer thioether amido sulfonate, was transformed into a suite of perfluorinated carboxylates with varying fluorocarbon chain lengths.  Sulfonamide-based polyfluorinated compounds, the main perfluoroalkyl substances in AFFF produced by 3M Corporation, also were transformed into perfluorinated carboxylates.   Heat-activated persulfate mineralized PFOA through a pathway involving formation of shorter chain perfluoroalkyl carboxylates, but only under acidic conditions (i.e., pH values below 4).  Neither treatment resulted in transformation of PFOS or the other perfluoroalkyl sulfonates in AFFF.  Heat-activated persulfate treatment under acidic conditions may be a feasible remedial strategy for source areas impacted by PFAS provided that geochemical conditions are conducive to groundwater acidification.  ISCO also may prove useful as a means of converting polyfluoroalkyl substances into perfluoroalkyl carboxylates as part of a treatment train. 

Ms. Maureen Sullivan is the Deputy Assistant Secretary of Defense for Environment, Safety and Occupational Health in the Office of the Assistant Secretary of Defense (Energy, Installations and Environment). She is responsible for DoD’s policies and programs related to compliance with environmental laws, greenhouse gas accounting and climate change adaptation, management of natural and cultural resources, cleanup of contaminated sites including emerging contaminants, and more. Ms. Sullivan oversees SERDP/ESTCP, as well as the Armed Forces Pest Management Board and the DoD Explosives Safety Board. For the past 25 years, Ms. Sullivan has served in various leadership positions as a member of the Office of the Secretary of Defense environmental staff, and possesses wide ranging experience in numerous DoD environmental programs to include Pollution Prevention, Environmental Compliance, Historic Preservation, and the Clean Air Act. Her total DoD career spans 35 years. Prior to joining the Office of the Secretary of Defense, she held positions with the Defense Logistics Agency in Virginia, Michigan, Ohio and Germany where she worked in hazardous waste management, international environmental activities and pollution prevention. Ms. Sullivan has been a member of the Senior Executive Service since 2008. She holds a Bachelor of Science in Natural Resource Economics from the University of Massachusetts at Amherst. 

Dr. Andrea Leeson is the Deputy Director of SERDP and ESTCP as well as the Program Manager for SERDP and ESTCP’s Environmental Restoration program area. Dr. Leeson has been with SERDP and ESTCP since 2001. Prior to that, she was a Research Leader at Battelle Memorial Institute where she conducted scientific research on in situ bioremediation and the design and implementation of innovative biological, chemical and physical treatment technologies for site remediation and industrial wastewater. She received her PhD in Environmental Engineering from the John Hopkins University. 

Dr. David Sedlak is the Malozemoff Professor in the Department of Civil and Environmental Engineering at the University of California at Berkeley.  He is also the Co-Director of the Berkeley Water Center and Deputy Director of the NSF engineering research center for Reinventing the Nation’s Urban Water Infrastructure (ReNUWIt).  He has over 25 years of experience studying remediation of organic contaminants in soil and groundwater.  Since 2009, he has been studying the oxidative treatment of perfluoroalkyl substances.  He is a member of the National Academy of Engineering and recipient of numerous awards including the NSF CAREER Award, the Paul Busch Award for Innovation in Applied Water Quality Research and the Clarke Prize for Excellence in Water Research.  Sedlak is the author of Water 4.0: The Past, Present and Future of the World’s Most Vital Resource and serves as editor-in-chief of the ACS journal, Environmental Science & Technology.  He is the recipient of a Bachelor’s degree from Cornell University (1986) and a PhD in Water Chemistry from the University of Wisconsin—Madison (1992).