Sludge in the Garden: Toxic PFAS in home fertilizers made from sewage sludge

Sludge in the Garden

Sludge in the Garden

Many home gardeners buy compost or commercial soil amendments to enhance soil nutrition. But new tests reveal concerning levels of toxic chemicals known as PFAS in fertilizer products which are commonly made from sewage sludge.


Our testing found PFAS or "forever chemicals" in all of the nine fertilizer products tested by the Ecology Center of Michigan and Sierra Club and marketed as “eco” or “natural.” Eight of the nine exceeded screening guidelines set by the State of Maine, the state with the strictest safeguards for PFAS contamination of agricultural lands. PFAS in fertilizers could cause garden crops to be a source of exposure for home gardeners.  

PFAS are per- and poly-fluoroalkyl substances, a class of widely used industrial chemicals, many of which are toxic to people, that persist for decades in the environment. In most places, industries are currently allowed to flush PFAS-containing waste into wastewater drains that flow to treatment plants. The chemicals are not removed during sewage treatment, and instead settle in solid materials that are separated out from liquids in the treatment process.  

Sludge in the Garden: Toxic PFAS in home fertilizers made from sewage sludge

Americans generate massive quantities of sewage waste each day. Nearly half of sewage sludges are treated to kill pathogens and then spread on farms, pastures and wildlands for disposal, where nutrients like nitrogen improve soil productivity. The wastewater industry and EPA call these “biosolids.” Unfortunately, biosolids carry a variety of persistent and toxic chemicals, in addition to PFAS, which can threaten our food supply and contaminate water sources. 

The Sierra Club and Ecology Center call for quick action to keep industrial polluters from discharging PFAS in their wastewater drains. Agencies must survey the hazard of food production on highly contaminated soils, and regulate land application of biosolids with high levels of PFAS and other chemicals. Industry must pay for the damages that PFAS production and use poses to people and the environment, including costly cleanups of contaminated places. The most efficient and effective way to protect people from the growing threat of PFAS exposure is to halt all uses of PFAS with limited exemptions.

Sludge in the Garden: Toxic PFAS in Home Fertilizers Made From Sewage Sludge

This report is a joint project of Sierra Club and the Ecology Center

Special thanks to Sierra Club volunteers: Denise Trabbic-Pointer and Stephen Colby Brown, and the Sierra Club Grassroots Network for funding the product testing..

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