Survey on the current leachate treatments of public municipal solid waste landfills and the potential impact of per- and polyfluorinatedalkyl substances in the Eastern and Northwestern United States.

Leachate from landfills can be a significant challenge to manage and treat due to conventional contaminants. The addition of emerging contaminants such as per- and polyfluorinatedalkyl substances (PFASs) makes treatment even more complex. PFASs enter landfills through consumer waste and have been detected in landfill leachates at varying concentrations. The design and decision-making on leachate treatment require essential information since it depends on local factors, e.g. climate, proximity to wastewater treatment plants, and waste type. This study conducted a survey on actively operated public municipal solid waste (MSW) landfills in the Eastern and Northwestern regions of the US to understand the current leachate treatment practices and views from public MSW landfill managers on PFAS treatment. The survey aims to explore the possible adaptations from the industry to the pending regulatory guidelines for the potential PFASs treatment. Results show the majority of the landfills are currently using off-site disposal (72% of the responses), followed by complete onsite treatment (18% of the responses) and pre-treatment onsite and off-site disposal methods (10% of the responses). The factors that guided the selection of treatment methods included climate, economics, and future regulations. Evaporation and recirculation were the most prevalent onsite treatment technologies for public landfills, which reduced the leachate quantity for treatment. The public landfills expressed awareness of the potential impact of PFASs on the changes in leachate treatment. The current state-level regulation, potential federal PFAS regulation, and treatment costs are raising awareness of the onsite treatment for PFASs. The results of this study will benefit the improvement of PFAS awareness and provide critical information that will directly affect the leachate treatment process for PFASs.Implications: This study presents a survey on the current leachate treatment process in the public municipal solid waste landfills in the eastern and northwestern U.S. and their potential process improvement on the impact of PFASs. This study is relevant to the topic of the JA&WMA because the research falls directly within the scope of this journal, and it documents the leachate treatment of landfills, and the results of this study will immediately contribute to our understanding of the waste treatment, benefiting the improvement of PFASs awareness, and providing critical information that will directly affect the leachate treatment process.