Getting PFAS out of biosolids isn’t easy. Some companies are trying

By Britt E. Erickson | C&EN | July 22, 2025

Read the full article by Britt E. Erickson (C&EN)

"A dairy farm in Arundel, Maine, triggered an alarm in 2016 when high levels of perfluorooctanesulfonic acid (PFOS) were detected on the property in a monitoring well for a public drinking-water system. The chemical hasn’t been produced in the US since 2002 but is one of many per- and polyfluoroalkyl substances (PFAS), often called forever chemicals, that persist in the environment.

The farmer reached out to the Maine Department of Agriculture, Conservation and Forestry (DACF) and asked, “What does this mean for my animals? They’re drinking this water as well,” says Meagan Hennessey, the department’s director of PFAS response. The farmer agreed to have milk from the cows tested for PFAS.

After finding high levels of PFOS in the milk, the department began working with a toxicologist at the Maine Center for Disease Control and Prevention to set a limit for PFOS in milk sold in Maine. PFOS has been linked to human health effects (PDF), including some cancers and adverse effects on the immune system, reproduction, and development."