Over the last several months, some community groups have questioned the safety and efficacy of biosolids being applied to farmland. The Ontario Biosolids Council – drawn from organizations representing the industry who manage the application of biosolids as a fertilizer and some of the municipalities that produce these biosolids for agricultural use – we are writing here to correct the misinformation being spread. Opinions are not facts, and the use of biosolids to enhance the soil quality and nutrient levels of Ontario farmlands is a well-regulated agricultural practice that is the very definition of environmental sustainability and our collective drive for a circular economy. The experts are not only those working in the industry, academia, governments and their agencies, but also a large group of scientists that have scientifically researched the safety and efficacy of biosolids for decades (and continue to do so, across Canada and the United States).
First, the terms biosolids and sewage sludge are not interchangeable. Biosolids are produced when municipal wastewater treatment facilities treat wastewater from residential, industrial and commercial sources into treated water and leftover solids. The treated water is normally discharged to a nearby stream or river, while the solids go through an additional treatment process to reduce the presence of potentially harmful micro-organisms and odours. Treated solids that meet the regulatory requirements, including quality standards, are known as biosolids.
It is only at this point that Ontario’s Ministry of the Environment, Conservation and Parks (MECP) and Ontario’s Ministry of Agriculture, Food and Agribusiness (OMAFA) will consider allowing these biosolids to be applied to farmlands. Ontario’s comprehensive Nutrient Management Act is then followed to provide a strict and effective regulation for their safe and productive use.
Yet, the province is not the only regulator. At a federal level, the Canadian Food Inspection Agency (CFIA) provides a further level of oversight through the Fertilizer Act, when biosolids are processed into pellets and used like any other traditional fertilizer – the same you might use on your lawn and garden. Here, the level of regulation has addressed the emerging concern of any possible contamination of fertilizers from so-called forever chemicals (per- and polyfluoroalkyl substances, or PFAS). In October 2024, this new regulation limited the amount of PFAS that can be found in fertilizers derived from biosolids to fifty parts per billion. For context, that’s the equivalent of three drops of water into a full Olympic sized pool. Protecting both farmers and all Canadians even further, this same regulation bans the importing of any such fertilizers that don’t meet this rigid standard from being allowed into the country at all.
This level of belt-and-suspenders regulation and oversight is important. As an industry, we welcome it and support its enforcement. That’s because the continued availability of biosolids is crucial to the farmers that use them and to the municipalities that produce them. It’s a win-win relationship.
The alternatives to land application – landfilling or incineration – are neither environmentally friendly nor sustainable. Moreover, they would unnecessarily add costs to municipal taxpayers while taking away real financial benefits from farmers (the value of land applied biosolids to farmers is $500 per hectare - that’s thousands and thousands of dollars a year of cost savings to each participating farmer).
As a council, we support the need for community groups to ask questions and get answers. But we cannot support the continued use of opinions over facts, fears over reality, and the widespread distribution of misinformation (all repeated as if these were facts).
The land application of biosolids is a science-based, historically safe, and well-regulated solution to two problems -the need to provide on-going nutrients to farmlands and the need to beneficially use a by-product of our municipal wastewater treatment systems – just as we treat our wastewater and then return it to the ecosystem from which it was originally drawn.
Phil Sidhwa,
Chair, Ontario Biosolids Council
www.ontariobiosolidscouncil.ca
