Imagine a noxious slurry teeming with heavy metals, industrial chemicals, viruses, bacteria, drug residues, and even radioactive material.
That’s sewage sludge – the solid waste left over after treating urban wastewater. This toxic stew contains concerning levels of contaminants like PFAS “forever chemicals” that accumulate in the environment without breaking down.
Spreading this hazardous sludge on farmland can have devastating consequences. Repeated application drastically increases soil levels of toxic elements to dangerous levels.
Heavy metals like cadmium, lead, and mercury accumulate, contaminating the earth in a largely irreversible way.
It’s something that threatens the very ground beneath our feet.
Widespread Sludge Use on Farmland
You might be shocked to learn just how common this risky practice is. The government has promoted spreading sewage sludge on agricultural fields as fertilizer since the 1990s as a disposal method (ref).
In 2018 alone, over 2 million dry tons of sludge were dumped on 46 million acres, which is 20% of all U.S. farmland (ref).
Nearly half of the sewage sludge generated in the country ends up on fields, with the rest used in landscaping, on golf courses, in forests, and even abandoned mines.
Sludge has become a go-to, low-cost fertilizer despite its toxic load. Bit by bit, more and more land is being poisoned each year.
The Toxic Sludge Threat – Health Risks
Sewage sludge poses serious health risks to people and animals alike:
- Hundreds have fallen ill after exposure, suffering respiratory distress, headaches, nausea, rashes, and even tumors.
- Heavy metals increase cancer risks (ref) and cause high blood pressure, anemia, and lung issues when inhaled or ingested.
- PFAS build up in the body over time, linked to cancer, birth defects, and other health problems.
- Sludge contains nasty pathogens like bacteria, viruses, and parasites that make people and animals sick.
- Contaminated sludge has sickened and killed livestock on farms where it was applied.
It’s a nightmare for farmers and a major threat to public health.
Contamination of Crops & Food Supply
Here’s where it gets even scarier – the toxins in sludge make their way into our food.
Heavy Metal Uptake in Crops
Heavy metals significantly increase levels of cadmium, nickel, copper, and zinc in the edible portions of crops. Even low levels of sludge metals reduced wheat yields by up to 10% in one study. (ref)
PFAS Contamination
PFAS leach into soil, groundwater, and plants, traveling up the food chain and onto your dinner plate. One Maine farm had water PFAS levels 400 times higher than state limits after using sludge. (ref)
Inadequate Regulations & Oversight
The EPA monitors only 9 of the thousands of pathogens in sludge and rarely inspects sludge use. There are no federal limits for PFAS in sludge, and regulators seek to address only a handful of the thousands of PFAS chemicals out there.
Experts at the CDC, National Research Council, and in the medical field have slammed these lax regulations. But meaningful action has been slow and piecemeal.
The Path Forward
As the risks of sludge become harder to ignore, some states are taking matters into their own hands. Maine has banned sludge spreading, restricted PFAS use, and funded farm cleanup.
Experts recommend cutting PFAS pollution at the source and holding polluters accountable for the damage they’ve caused.
Legislation like the PFAS Action Act (ref) would regulate PFAS as a class and support impacted communities. But ultimately, we need to phase out using sewage sludge on agricultural land altogether.
Don’t Miss These:
Wood Burners Beat Traffic as Top Pollution Source, Study Shows
13 Rare Plants That Could Disappear From Gardens Worldwide
Labyrinths Aren’t Relics—6 Reasons They’re Timeless and Thriving
Fig Leaves Are the New Superfood: 4 Key Benefits
This Rare Succulent Is Cute, Coveted—and Facing a Crisis
17 Reasons Baby Boomers Aren’t Joining the Downsizing Trend
The Timeless Appeal of Kitchen Gardens: Survival, Status, and Revival
History’s Guardians: 15 Castles That Time Couldn’t Defeat
Davin is a jack-of-all-trades but has professional training and experience in various home and garden subjects. He leans on other experts when needed and edits and fact-checks all articles.