Pilot Study of Per- and Polyfluoroalkyl Substances (PFAS) Infiltration to Shallow Groundwater Through Selected Soils in New Hampshire, 2023

In a study conducted by the U.S. Geological Survey (USGS) and the New Hampshire Department of Environmental Services, detectable concentrations of per- and polyfluoroalkyl substances (PFAS) were found in the soil at every site despite targeting locations with no known PFAS sources (Santangelo and others, 2022). The widespread distribution of PFAS concentrations in New Hampshire has since sparked critical interest into understanding whether recharge to groundwater contains significant concentrations of PFAS after infiltration through soils. To address this concern, the USGS implemented a pilot study designed to evaluate whether PFAS infiltrate through shallow soil into shallow groundwater. Five sites were selected based on previously observed PFAS concentrations, soil type, aquifer materials, elevation, groundwater depth, and geographic location (Santangelo and others, 2022). At each sample site, one pushpoint sampler was installed down-slope of new soil sample points. At one sample site, two stainless steel lysimeters were installed at two varying depths above the water table, and up-slope of the pushpoint sampler. Seven shallow soil samples were submitted for PFAS, total organic carbon, and pH analysis. Twelve groundwater samples and four porewater samples were also submitted for PFAS analysis. Quality-control samples consisted of a source solution blank, three equipment blanks, and five sample duplicates.
Reference:
Santangelo, L.M., Tokranov, A.K., Welch, S.M., Schlosser, K.E.A., Marts, J.M., Drouin, A.F., Ayotte, J.D., Rousseau, A.E., and Harfmann, J.L., 2022, Statewide survey of shallow soil concentrations of per- and polyfluoroalkyl substances (PFAS) and related chemical and physical data across New Hampshire, 2021: U.S. Geological Survey data release, https://doi.org/10.5066/P9KG38B5.