Professor of Civil, Architectural, and Environmental Engineering and Associate Dean for Research
University of Miami
Helena Solo-Gabriele is Professor of Civil, Architectural, and Environmental Engineering at the University of Miami, Coral Gables, Florida where she also serves as the Associate Dean for Research. After receiving her PhD in Civil/Environmental Engineering at the Massachusetts Institute of Technology, she joined the faculty at the University of Miami where she has conducted research and taught courses in environmental engineering for the past 25 years and served as Associate Dean for the past 15 years. Dr. Solo-Gabriele’s research focuses on fate and transport of contaminants in the environment with an emphasis on contaminants that are of human health concern. She has been funded to evaluate poly- and per-fluoroalkyl substances at landfills through grants funded by the Hinkley Center for Solid and Hazardous Waste Management and through the U.S. Environmental Protection Agency. Her work in this regard focuses on evaluating the fate of PFAS in landfill leachates, relationships with physical-chemical parameters, and the feasibility of on-site treatment systems. She collaborates closely with colleagues from the University of Florida (Tim Townsend, PI) where collectively they have been focusing on the fate of PFAS from landfill incinerator ash. Dr. Solo-Gabriele has published over 130 peer-reviewed journal articles many of which have documented the sources and distribution of contaminants in the disposal sector. She is currently serving as an expert member of the Guidelines Development Group of the World Health Organization for updating the Guidelines for Safe Recreational Water Environments. She also serves as an External Advisory Board member of the Oceans and Human Health and Climate Change Interactions at the University of South Carolina. Dr. Solo-Gabriele is a Fellow of the American Society of Civil Engineers.
Implications of PFAS in Landfill Leachates
Helena Solo-Gabriele1, Yutao Chen1, Hekai Zhang1, Yalan Liu2, Nicole Robey2, Timothy Townsend2
Landfills receive discarded consumer products, many of which contain poly- and perfluoroalkyl substances (PFAS). As a result, leachates from landfill have elevated levels of PFAS. This study focused on evaluating 26 PFAS species (11 perfluoroaklyl carboxylic acids, 7 perfluoroalkyl sulfonates, 5 fluorotelomers, and 3 perfluorooctane sulfonamides) within aqueous samples collected from 33 landfills. Eleven of these landfills had on-site leachate treatment systems (5 evaporation ponds, 2 aeration systems, 1 sand filtration, 1 powdered activated carbon, 2 reverse osmosis). Samples collected included groundwater, stormwater, gas condensates, and leachates from municipal solid waste (MSW), construction and demolition waste (C&D), and MSW ash (MSWA). Results show that total PFAS concentrations were variable within groundwater and storm water with mean levels for groundwater of 1,100 ng/L and for storm water of 700 ng/L. The sites with highly elevated total PFAS in groundwater (5,000 to 10,000 ng/L) were characterized by unique landfill designs that could have contributed towards the elevated levels. Higher levels were observed in gas condensate (mean of 11,500 ng/L) with this liquid type representing the highest concentration measured to date through the current study (maximum of 81,000 ng/L). Among the landfill leachates, MSWA tended to have the lowest levels of total PFAS on average (mean of 7,500 ng/L), followed by C&D (mean of 9,700 mg/L) and MSW (mean of 18,500 ng/L). Among the treatment systems reverse osmosis was the most effective with over 99% reductions in total PFAS within the permeate. Mass balance analysis is needed to assess removals afforded through landfill pre-treatment and the relative contribution of treated and untreated leachates to receiving water bodies which may include deep well injection, wastewater treatment plants, and water reuse systems.