The Promise of a Closed Loop
For decades, the story of biosolids has been framed as an environmental success. Wastewater treatment plants, faced with the challenge of disposing of treated sewage sludge, developed a process to transform it into a nutrient-dense fertilizer. This material, rebranded as 'biosolids,' was offered to farmers as a cost-effective way to enrich their soil with nitrogen and phosphorus, boosting crop yields. The logic seemed irrefutable: a perfect, closed-loop system where urban waste nourishes rural land. Municipalities saved on landfill costs, farmers saved on fertilizer, and a waste product was repurposed for a beneficial use. It was a cornerstone of recycling and sustainability long before those terms became fashionable. But the loop was never truly closed. It was, and is, an open conduit for industrial and consumer waste to flow directly onto the fields where we grow our food.
A Chemical Legacy in Every Flush
The problem lies in what wastewater treatment plants were never designed to handle: per- and polyfluoroalkyl substances (PFAS). These 'forever chemicals,' a class of thousands of compounds used for decades in everything from non-stick pans and waterproof jackets to firefighting foam and food packaging, are exceptionally stable. Their carbon-fluorine bond, one of the strongest in organic chemistry, allows them to resist heat, oil, and water, but also makes them nearly indestructible in the environment. When you wash a waterproof jacket or a non-stick pan, or when industrial facilities discharge their waste, PFAS enter the sewer system. They arrive at the wastewater treatment plant, where the treatment process, designed to break down organic waste and kill pathogens, has virtually no effect on these resilient chemicals. Instead, the PFAS compounds concentrate in the solid sludge. This contaminated sludge is then processed, stabilized, and rebranded as the very biosolids spread on farmland.
The wastewater treatment plant, in this scenario, acts as a concentrating machine. It takes diffuse streams of PFAS from countless sources and funnels them into a potent, solid form, which we then deliberately apply to our agricultural lands.
This isn't a theoretical risk. It's a documented crisis unfolding across the country. The Environmental Working Group estimates that up to 20 million acres of U.S. farmland may have been fertilized with PFAS-contaminated sludge. The consequences for farmers have been catastrophic. In Maine, a state that once championed biosolids, widespread contamination has been discovered on dairy farms, in hayfields, and in drinking water wells. Farmers who did everything right, following state guidelines for biosolid application, now face financial ruin. Their milk is unsellable, their beef is tainted, and their land—often in their families for generations—is poisoned. Stoneridge Farm in Arundel, Maine, became a grim poster child for this crisis, forced to dump thousands of gallons of contaminated milk and ultimately cease operations after discovering dangerously high levels of PFAS in their cows, soil, and water, traced directly back to state-licensed biosolids applied decades earlier.
From Soil to Supper Plate
Once in the soil, PFAS do not stay put. Their chemical properties allow them to be readily absorbed by plants. Different crops uptake the chemicals at different rates, but studies have confirmed their presence in everything from leafy greens and grains to fruits and vegetables. The contamination doesn't stop there. Livestock grazing on contaminated pasture or consuming contaminated feed and water accumulate these chemicals in their bodies. PFAS have been found in the meat, milk, and eggs of farm animals, creating a direct pathway from a treated sewer pipe to the American dinner table. Because these chemicals bioaccumulate, their concentration increases as they move up the food chain. This means that even low levels of contamination in soil and water can lead to significant levels in our food. The U.S. Food and Drug Administration has acknowledged the issue, finding PFAS in samples of grocery store foods like fish, meat, and chocolate cake, but the full extent of the problem remains largely unknown due to a lack of systematic testing.
A Regulatory Void
The core of the problem is a catastrophic failure of regulation. The U.S. Environmental Protection Agency (EPA) has, for decades, promoted the use of biosolids under its 'Part 503 Rule,' which sets standards for pathogens and heavy metals but is silent on PFAS. While the EPA has recently taken steps to address PFAS in drinking water, setting new Maximum Contaminant Levels (MCLs) and designating two of the most notorious compounds, PFOA and PFOS, as hazardous substances under Superfund law, it has not established federal limits for PFAS in biosolids. In January 2025, the agency released a draft risk assessment acknowledging that even very low levels of PFAS in biosolids could pose health risks, but this has yet to translate into enforceable rules. This regulatory vacuum has left states to fend for themselves. Maine, having experienced the crisis firsthand, became the first state to ban the land application of biosolids altogether in 2022. Other states, like Michigan and Maryland, have implemented testing requirements and interim guidance with concentration limits. But this patchwork of state-level responses is insufficient to address a national crisis. Without a strong federal standard, contaminated biosolids from states with weak regulations can still be transported and sold in states with stronger ones, perpetuating the cycle of contamination.
The Path Forward: From Disposal to Destruction
At the EPR Foundation, we believe that continuing the land application of PFAS-contaminated biosolids is an act of gross negligence. The 'win-win' narrative has been exposed as a lie. We are sacrificing the long-term health of our soil, our water, and our citizens for the short-term convenience of sludge disposal. The only responsible path forward is to end this practice and treat contaminated biosolids for what they are: a hazardous waste. This requires a fundamental shift in how we manage wastewater solids. We must invest in and rapidly scale up technologies capable of destroying PFAS, such as supercritical water oxidation and pyrolysis. These processes use high temperatures and pressures to break the carbon-fluorine bond, breaking down the 'forever chemicals' into their harmless constituents. While these technologies are more expensive than land application, the cost of inaction is infinitely higher. The $51 billion cleanup bill for existing contamination is a testament to that fact. We must also prioritize source reduction. Industries that use and discharge PFAS into our sewer systems must be held accountable and required to pre-treat their waste streams. We cannot continue to place the burden of cleaning up industrial pollution on public wastewater utilities and, by extension, the farmers and communities they unwittingly poison.
The era of spreading sewage on our fields must come to an end. It's time to stop fertilizing with forever chemicals and start investing in real solutions that protect our food supply and our future. We must demand that the EPA act decisively to regulate PFAS in biosolids and support the development of destruction technologies that can finally, and safely, close the loop.