Matthew Nagorzanski, Darrin Thompson, and David Cwiertny

Per- and polyfluoroalkyl substances, PFAS, number in the thousands, and are characterized by their partial, or complete, fluorination of a carbon chain. This fluorination allows PFAS chemicals to be resistant to heat, water, oil, and time, earning the nickname “forever chemicals”. While these chemicals are extremely useful in their intended applications, the ubiquitous use of PFAS over decades has led to persistent contamination of many ground and surface waters. Research into PFAS chemicals thus far has painted a picture of widespread contamination, and exposure to PFAS has been linked to negative human health outcomes like cancer and elevated cholesterol levels. Due to this danger to human health, the Environmental Protection Agency recently finalized Maximum Contaminant Limits, or MCLs, for a select few PFAS chemicals, notably 4 ppt for perfluorooctanoic acid, PFOA, and perfluorooctanesulfonic acid, PFOS. Because of these finalized regulations, much of PFAS investigations in Iowa have focused on contamination in public water systems. But this focus can often miss threats from PFAS in more rural Iowan communities who often rely on unregulated private wells for their drinking water. To better understand the scope of PFAS contamination in Iowa and potential factors influencing this contamination, we sampled various groundwater wells, surface waters, and public drinking water systems across Iowa. Preliminary data has shown that many surface waters are contaminated with PFAS chemicals, often at or slightly above our reporting limit of 1 ppt, with these concentrations potentially influenced by seasonal trends. We also found PFAS contamination in groundwater wells near sources of PFAS contamination, like airports or wastewater treatment plants, as well as in wells that are recharged from contaminated surface water, like wells near the Mississippi River. These groundwater wells represent a major human health concern, as some of the more contaminated wells tested reported levels of PFOA and PFOS ranging from 10 to 20 times greater than the finalized MCLs. Together, this work represents a concentrated effort to further quantify PFAS contamination in Iowa surface and ground water, as well as identify some potential PFAS sources and trends influencing PFAS concentration, to help assess the scope of PFAS contamination and inform Iowans of their risk.