State Groundwater Study Found PFAS Within Roughly 7 in 10 Private Wells

Monday, November 6th, 2023 -- 9:12 AM

(By Danielle Kaeding, Wisconsin Public Radio) A statewide groundwater study has found PFAS within roughly 7 in 10 private wells, but state environmental regulators say areas with significant contamination from the chemicals are limited.

According to Danielle Kaeding with the Wisconsin Public Radio, the Wisconsin Department of Natural Resources released the findings Friday as part of a study conducted with funding from the U.S. Environmental Protection Agency.

The study was published Thursday in the peer-reviewed scientific journal Environmental Science & Technology. Under the study, researchers with the DNR, University of Wisconsin-Stevens Point and Wisconsin State Lab of Hygiene collected 450 samples from homes with shallow private wells no deeper than 40 feet throughout Wisconsin last summer and fall, most of which had PFAS levels below state health recommendations.

Overall, the research found human waste, particularly septic systems, are significant sources of the chemicals. The highest levels of PFAS found may stem from waste spread on farmland. Researchers analyzed samples for 44 individual PFAS, or per-and polyfluoroalkyl substances.

Tests detected at least one chemical in 71 percent of samples, and 22 substances were found in one or more samples. Less than 4 percent of samples, 17 out of 450, went beyond the EPA’s proposed drinking water limits of 4 parts per trillion for two of the most widely studied chemicals: PFOA and PFOS. Two samples contained the chemical PFHxS at levels concerning to federal environmental regulators.

"Those samples above the referenced PFAS levels tend to be associated with developed land and human waste indicators (artificial sweeteners and pharmaceuticals), which can be released to groundwater via septic systems," the study reads.

The study also found samples of PFOA, PFOS, and PFHxS that had levels greater than 40 parts per trillion may be tied to "application of wastes to agricultural land." PFAS are a class of thousands of synthetic chemicals widely used by industry since the 1940s.

They’ve been used in everyday products like nonstick cookware, food wrappers and firefighting foam. The chemicals don’t break down easily in the environment. Research shows high exposure to PFAS has been linked to kidney and testicular cancers, fertility issues, thyroid disease and reduced response to vaccines over time.

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