In this episode of The NextDrop Question, I speak with Ali Ling, Assistant Professor of Civil Engineering at the University of St. Thomas, during the Battelle Chlorinated Conference in Dallas.
Ali’s work focuses on wastewater treatment, emerging contaminants, and the practical economics of PFAS management. What makes her perspective especially useful is that she does not stop at the question of whether treatment can work. She asks what it costs, who pays, and what kind of benefit the spending is actually producing.
Our conversation focused on a deceptively simple issue: how should we talk about PFAS treatment and remediation costs?
Ali makes an important distinction. For drinking water treatment, the relevant benefit is often exposure reduction. That means cost should be interpreted against the amount of PFAS intake or risk being reduced. For remediation and broader environmental management, the question is often different. There, cost may need to be evaluated per kilogram of PFAS removed, destroyed, sequestered, or otherwise taken out of the mobile environmental burden.
That distinction matters because PFAS management is not one problem. Drinking water treatment, wastewater, landfill leachate, biosolids, contaminated sites, emissions reduction, and product-use reduction each sit at different points in the system. A single cost metric can make these interventions look comparable when they are actually serving different goals.
Ali also discusses why downstream remediation alone cannot solve the PFAS mass-balance problem. Recent work from her group suggests that even broad intervention across wastewater, landfills, biosolids, and heavily contaminated sites may address only a small fraction of current PFAS emissions, pointing to the importance of better understanding diffuse pathways such as air and stormwater.
This conversation is a useful reminder that PFAS cost discussions should start with a sharper question: cost to do what?
A focused question. A practical takeaway. See you next time.
