Waste type, incineration, and aeration are associated with per- and polyfluoroalkyl levels in landfill leachates

Per- and polyfluoroalkyl substances (PFAS) are found in many consumer products which will be ultimately disposed in landfills. Limiting environmental contamination and future exposures will require managing leachates from different types of landfills, each with different PFAS levels depending upon the source of the waste. The objective of this study was to evaluate the influence of waste type and on-site treatment on PFAS levels in landfill leachates. Eleven PFAS species (7 carboxylic acids, 3 sulfonic acids, and 5:3 fluorotelomer carboxylic acid) were evaluated in leachates from municipal solid waste (MSW), construction and demolition (C&D), MSW ash (MSWA), and a mixture of MSWA and MSW with landfill gas condensate (MSWA/MSW-GC). Leachates were also analyzed before and after on-site treatment at two of these facilities. Results indicate that MSWA leachate had significantly lower PFAS levels relative to other leachate types. Lower total PFAS concentrations in MSWA leachates were correlated with an increase in incineration temperature (R² = 0.92, p = 0.008). The levels of PFAS in untreated C&D and untreated MSW leachate were similar. The levels of targeted PFAS species in MSW leachate for one of the facilities evaluated increased after on-site landfill treatment presumably due to the conversion of PFAS precursors in the untreated leachate sample.