What happened
Maine has the dubious distinction of being the first U.S. state to comprehensively test agricultural land for PFAS contamination — and the first to find what other states almost certainly have but have not yet measured.
Beginning in 2018 and accelerating through 2022, Maine's Department of Environmental Protection (DEP) tested farms that had historically received "biosolids" — treated sewage sludge — applied as fertilizer. The state found PFAS in soil, groundwater, and animal products on dozens of operations. Several dairy farms had milk PFOA and PFOS levels high enough that the state ordered the herds destroyed. Others have closed operations entirely.
In April 2022, Maine became the first U.S. state to ban biosolids land application outright (with limited exceptions). A handful of other states (Michigan, Connecticut, New York) have introduced more limited testing and labeling regimes since. The federal government has not moved.
Our take
The biosolids problem is one of the most quietly consequential environmental scandals of the past decade, and almost no one outside the affected farming communities has heard of it.
Sewage sludge from municipal wastewater plants contains everything that gets flushed down American drains and laundered out of synthetic clothing — a major route by which industrial PFAS, residential PFAS-treated fabrics, and food-packaging PFAS end up concentrated in a solid waste stream. For decades, "Class A" treated biosolids have been marketed as a beneficial soil amendment, and spread on farmland nationwide.
The honest problem: there is no PFAS-removal step in conventional wastewater treatment. PFAS is not destroyed in the digesters that handle sludge. It accumulates. Application to farmland is, in effect, a slow transfer of urban industrial PFAS to rural agricultural land and groundwater.
The downstream impacts in Maine were not subtle. One dairy operation tested at milk PFOA levels nearly 200 times the FDA's recommended action level. Farm groundwater testing on impacted properties has run in the hundreds to thousands of nanograms per liter — orders of magnitude above the new EPA drinking-water MCL of 4 ng/L.
Maine's response has been the most aggressive in the country: outright ban, mandatory testing of milk and water on suspect farms, a state superfund-like program for impacted landowners. Other states with comparable historical biosolids application practices — almost the entire country — have not undertaken comparable testing.
The brutally honest read: PFAS-contaminated farmland is almost certainly a national problem. Maine is not unique; it is unique only in having looked. Until other states test, the absence of evidence will continue to be misread as evidence of absence.
What this means for readers: if you live in a rural area with extensive historical biosolids application — particularly in dairy country, vegetable production, or near municipal land-application sites — private well testing for PFAS is a defensible step. The federal MCL only applies to public water systems. Private wells are on their own.
Sources
- Maine DEP. PFAS in Maine.
- EPA. Per- and Polyfluoroalkyl Substances (PFAS).
- USGS. PFAS in U.S. Tap Water (2023).