Forever Chemicals Creep Into U.S. Farmland Via Biosolids

For decades, American wastewater treatment plants have had an answer to their sludge problem: spread it on farmland. It works. Biosolids—the nutrient-rich residue left after sewage treatment—restore nitrogen and phosphic acid to exhausted soil at a fraction of the cost of commercial fertilizer. Farmers get cheaper inputs. Utilities get a disposal method. Everyone wins.

Except when the sludge is contaminated with PFAS.

“Forever chemicals” — so named because they don’t break down in soil or water — have been creeping into America’s agricultural heartland via biosolids for years. Now, regulators are finally waking up. The EPA released draft guidance on July 1 to help wastewater utilities and farmers reduce risk from PFOA and PFOS in biosolids. Days later, Pennsylvania’s Department of Environmental Protection announced proposed monitoring rules that would be the first statewide limits on PFAS in biosolids applied to farmland.

The scope is staggering. An estimated 2.96 million acres of U.S. cropland are significantly affected by PFAS, much of it via biosolids application. Once in the soil, PFAS don’t stay put—they leach into groundwater, accumulate in crops, and work their way into livestock and, ultimately, into the bodies of farmworkers and consumers.

The Contamination Pathway

The story is depressingly simple. Industrial polluters—makers of nonstick cookware, firefighting foam, water-resistant clothing—have used PFAS for decades. Once dumped or released, PFAS end up in sewage. Wastewater treatment plants remove much of the sludge but not the chemicals themselves. The biosolids get land-applied as a cheap fertilizer. The PFAS stays in the soil forever.

Land-applied biosolids are among the most significant contributors of PFAS to agricultural soils, a pathway that wasn’t even monitored until now. Pennsylvania’s proposed rule marks the first time the state requires wastewater treatment facilities to test biosolids for PFOS and PFOA before land application. The rule would prohibit spreading biosolids with PFOS or PFOA levels at or above 100 micrograms per kilogram.

Farmers applying these biosolids in good faith—thinking they’re getting a regulatory-approved soil amendment—have unknowingly been poisoning their own land.

The Regulatory Shift

Pennsylvania’s move is significant. By opening a 60-day public comment period (running through September 2), DEP is preparing to regulate something the farm industry has relied on for generations. It’s also a sign that other states may follow, creating a patchwork of rules farmers will need to navigate.

The EPA’s July 1 guidance offers recommendations to wastewater utilities, landowners, and farmers on how to reduce PFAS risk—though the specifics remain to be seen as the draft guidance moves toward finalization.

Neither the EPA nor Pennsylvania’s DEP are moving fast enough for the millions of acres already contaminated. But they are moving.

The Glimmer of Hope

While regulation is essential, science is offering an actual solution. Yale researchers have developed a two-step remediation process that costs just $1,460 per hectare annually—a stunning reduction from the $800,000 to $1.6 million per hectare required by existing methods. Rather than rendering land unusable (as current approaches do), the Yale method allows farmers to keep working while the soil heals.

The process starts with crushed alkaline rock spread over contaminated soil to raise pH and accelerate PFAS removal through plants. The harvested plants are then converted to biochar through heating, which destroys both PFOS and PFOA. As a bonus, the biochar sequesters atmospheric carbon, potentially eliminating 10.5 million metric tons of CO₂ annually at national scale.

The research, published in Proceedings of the National Academy of Sciences in 2026, offers a lifeline to farmers who’ve unknowingly inherited a forever-chemical problem they didn’t cause.

What’s Next

Farmers who suspect PFAS contamination should contact their state’s environmental protection agency and consider soil testing. For those applying biosolids, demand proof of PFAS testing—or skip the practice entirely until standards tighten. The EPA and state regulators have finally acknowledged the problem. Now the work of undoing decades of chemical creep begins.

The good news: it’s possible. The hard news: it should have been regulated years ago.

Related: Regenerative agriculture offers a pathway forward for soil restoration, USDA’s regenerative feedstock rule backs farmers transitioning to healthier practices, and the newest research on regenerative feedstock standards shows measurable soil improvement.