Ecological Risks of Per and Polyfluoroalkyl Substances (PFAS)

Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) have been widely used in numerous applications since the 1950s, including aqueous film forming foams (AFFFs) used for fire suppression at airports, firefighting training facilities, and other industrial locations.  Many sites host ecological habitat, or, due to the offsite transport potential for PFAS, PFAS-impacted sites may affect nearby and downgradient areas.  Ecological Risk Assessments (ERAs) are commonly needed at these sites to enable decision making related to investigation and remediation.

This presentation will provide an overview of PFAS ERAs, including a state-of-the-science overview of the fate, exposure, and toxicity of PFAS in ecosystems.  Much of the presentation will focus on our recently-released guidance document on PFAS for the United States Department of Defense’s Strategic Environmental Research and Development Program (SERDP), available for download at: https://www.serdp-estcp.org/Program-Areas/Environmental-Restoration/ER18-1614.  This guidance provides pragmatic approaches for addressing PFAS ecological risks at AFFF-impacted sites, but is also applicable to sites impacted by other PFAS sources. In addition, we will also provide practical examples from ERAs for PFAS conducted in the US and Australia, including advice on decision-making approaches involving Australian and New Zealand guidelines for fresh and marine water quality.

Dr. Jason Conder is a Principal at Geosyntec Consultants in Huntington Beach, California. He has more than 15 years of experience in environmental toxicology, ecological and human health risk assessment, bioaccumulation and bioavailability of environmental contaminants, environmental chemistry, environmental monitoring technology, and statistics. Dr. Conder has provided technical expertise in ecological risk assessment and environmental toxicology to multinational clients addressing environmental liability and risk issues associated with contaminated sites. A key part of his focus during the last 14 years has included Per- and Polyfluoroalkyl Substances (PFAS), including several product- and site-specific fate and risk assessments and authoring two key review articles on PFAS use, fate, terminology, and bioaccumulation. Dr. Conder also led a team to write a guidance document on ecological risk assessment of PFAS for the United States Department of Defense.  He has published more than 20 peer-reviewed articles in Environmental Toxicology and Chemistry, presented technical work at numerous international scientific conferences, and has served on and co-chaired several technical workshops.

Ms. Emily Larson is a Scientist at Geosyntec Consultants in Layfatette, Colorado.  She has over 8 years of consulting experience in human and ecological risk assessments and contaminated site investigations.  Emily also has environmental field experience including sampling soil, surface water, groundwater, and vegetation, and has participated in a multi-year fish population study.  Emily has experience with Superfund (CERCLA) as well as several state-led programs specifically in the Inter Mountain West and Pacific Northwest regions.  She has worked with several different clients in both the private and the public (state and federal) sector.  A key part of her practice includes PFAS, including several ongoing investigations and risk assessments, as well as assisting with a strategic review of PFAS liability and management for a Fortune 50 company.  Ms. Larson recently published an approach for evaluating avian exposures through an ecological risk model to seven prominent PFAS using data from five Aqueous Film Forming Foam (AFFF) sites and was a key contributor to a guidance document on ecological risk assessment of PFAS for the United States Department of Defense.