Dr. Dokou has been awarded a grant, in collaboration with researchers from the University of Connecticut led by Dr. Nefeli Bompoti, to study per- and polyfluoroalkyl substances (PFAS) transport in the subsurface. PFAS are a class of contaminants used in widespread industrial and commercial applications in the past 60 years. PFAS are of particular concern due to their widespread distribution and persistence in the environment, and potential adverse health effects to humans. Although PFAS uses have declined following industry phase outs in the early 2000s, communities still remain vulnerable given substantial exposures from contaminated sources of drinking water.
The proposed research will be explored through a series of experiments and modeling exercises under various conditions. Sampling activities will be conducted at a PFAS-impacted location in Killingworth, CT where fire-fighting training activities using AFFF resulted in widespread contamination in both soils and groundwater. Sampling activities will include identification of PFAS levels and background concentrations in soils and groundwater. PFAS partitioning in the solid phase will be determined through batch adsorption experiments with the objective to estimate partitioning coefficients under various environmental conditions. Field measurements and experimental data will be further utilized to calibrate and validate a flow and transport model using the HYDRUS software to simulate both unsaturated and saturated conditions. An assessment of changing environmental conditions including precipitation patterns, PFAS subsurface levels, and pumping rates will evaluate the potential impact of PFAS contamination in the area under different scenarios.
Given that PFAS-impacted soil may serve as a long-term diffuse source for PFAS in groundwater, the goal of this project is three-fold: a) investigate the retention of PFAS in the vadose zone and estimate the factors that control their leaching to groundwater; b) delineate the extent of PFAS contamination in the impacted area and capture the full spectrum of PFAS compounds present; and c) integrate the experimental and field findings into the development of a fate and transport model with predictive capability.
The benefits of this research will extend to providing insights to the policy makers and stakeholders towards identification of the existing PFAS plume in the area and cost-effective methods for management of historical PFAS releases in the State of Connecticut.