A new report has revealed that sewage sludge that wastewater treatment districts across America package and sell as home fertilizer contains alarming levels of toxic PFAS, also known as forever chemicals. Sludge which is called biosolid and slightly treated is used by consumers to fertilize home gardens. The PFAS levels raise concerns that vegetables are being contaminated by the chemical and harming those who eat them.
“Spreading biosolids or sewage sludge where we grow food means some PFAS will get in the soil, some will be taken up by plants, and if the plants are eaten, then that’s a direct route into the body,” said Gillian Miller, a co-author and senior scientist with the Michigan-based Ecology Center.
The testing, conducted with Sierra Club, checked nine brands of biosolids and found the chemicals and at levels that exceed standards set for two common types of PFAS. The biosolid brands are sold at stores like Ace Hardware, Menards, Lowes, and Home Depot. PFAS is a class of about 9,000 compounds that are used across many industries to make grease-resistant, stain, products water. They also cause health problems like liver disease, endocrine disruption, birth defects, and cancer. They are known as forever chemicals because of their longevity in the environment once introduced.
Industries that produce or use PFAS often discharge the chemicals into public sewer systems, where they travel to wastewater treatment plants, along with other human and industrial waste. From the wastewater is extracted, treated, and released back into waterways. In the treatment plants, a semi-solid mass of sludge remains, and to dispose of in landfills it is expensive for water treatment facilities. It holds phosphorus, nitrogen, and other nutrients that help crops grow. In recent years it is treated and sold as home fertilizer or given away to farmers.
Human excrement from which sludge derives has mixed with any number of 80,000 manmade chemicals that are otherwise pumped into the sewer system or discharged from the industry’s pipes. Most living organisms in biosolids are killed during the treatment process, and treatment plants screen sludge for heavy metals but it can still be full of PFAS, PCBs, pharmaceuticals, and other toxic chemicals that aren’t removed.