The regulation of municipal sludge would be “a notable improvement”, but the Union of Agricultural Producers insists: its use as fertilizer remains “controversial”. This is what the union organization argued in the context of a government consultation that ends this Saturday.
What exactly are we worried about?
Sewage sludge from municipal wastewater treatment has been used as fertilizer in Quebec fields for decades. These by-products are also called biosolids, fertilizing residual materials (FRM) or “human manure.”
PHOTO EMILY ELCONIN, THE NEW YORK TIMES ARCHIVES
Cows at this Brighton, Michigan, farm can no longer be raised commercially after high levels of PFAS contamination were detected in the animals and soil.
In the United States, farmers who have spread the sludge have found their land contaminated with high levels of perfluoroalkyl and polyfluoroalkyl substances (PFAS). Even spreading the sludge on neighboring land has reportedly made animals sick, the New York Times.
What does this have to do with us?
With Maine having banned these sprayings, its wastewater treatment plants must find other outlets. Human manure from Maine was thus sent to Quebec, a Radio-Canada report revealed in late 2022. In March 2023, Environment Minister Benoit Charette announced a moratorium on the spreading of biosolids imported from the United States, while Quebec adopts a limit for PFAS1In July, the Ministry of the Environment, the Fight against Climate Change, Wildlife and Parks published its draft regulation.2which includes a Code for the management of fertilizing residual materialsThe public consultation ends this Saturday evening.
Why use “human manure”?
Quebec favors recycling municipal sludge by spreading, and not landfilling or incineration, which are sources of greenhouse gases. Sludge from factories (especially paper and agri-food) is also used. Their nitrogen and phosphorus content allows farmers to buy less mineral fertilizers. The material used in the fields must respect certain limits (chemical contaminants, pathogens, odor load, foreign bodies), but there are no standards for PFAS yet.
What about human health?
Long-term exposure to certain PFAS can decrease the immune response to vaccination, imbalance lipids (such as cholesterol) in the blood, reduce birth weight and increase the risk of kidney cancer, but many uncertainties remain, indicates the National Institute of Public Health of Quebec.
In Quebec, the spreading of municipal sludge is not permitted on crops intended for human consumption or on pastures.
“In sites where a lot of PFAS have been used in France, we see that concentrations in the soil have increased [mais] “Organic matter in the soil still retains quite a lot of PFAS, so there is not much transfer to plants,” explains Sébastien Sauvé, professor of environmental chemistry at the University of Montreal.
PHOTO MORGANE CHOQUER, LA PRESSE ARCHIVES
Sébastien Sauvé, professor of environmental chemistry at the University of Montreal
Furthermore, Canada does not have any factories that manufacture PFAS, near which “the worst cases” have been discovered in the United States. And in Quebec, “the regulations for the use of sludge, regardless of PFAS, are still more restrictive; we cannot put as much as in the United States in a field.” Mr. Sauvé launched a research project to analyze the soil and well water of fields that received sewage sludge for several years.
Is the Quebec draft regulation relevant?
However, it is “urgent to have regulation and control,” believes Mr. Sauvé.
The regulation aims to establish limits for so-called “emerging interest” contaminants, which will be included in a new category called “preventative investigators.”3.
Quebec is proposing limits for perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), as well as for a combination of 11 PFAS. “I don’t understand why they’re only targeting 11 PFAS,” Sauvé said. “Even the worst private labs that analyze PFAS in Quebec do about 20. They should put 25, choose the good ones, and then their approach would be valid.”
What do farmers think?
“There has been a step forward, but we remain extremely cautious about this matter, and we do not promote it to farmers. We even tell them to be very careful,” Charles-Félix Ross, general director of the Union des producteurs agricoles (UPA), told us.
In its comments to the Ministry, the UPA mentions “the totally unreasonable quantity of shredded plastic” found by farmers after spreading biosolids and green waste, which Radio-Canada reported. “If this type of highly visible contamination can still occur, how can we not fear that much more insidious chemical and microbiological contamination could also occur?” writes the agricultural union.
Is this “recycling” widespread here?
Only 4.3% of cultivated land received residual fertilizing materials, shows the Ministry’s 2015 report. But the reports broadcast since 2022 have caused a “breach of trust [qui] “resulted in a reduction in quantities,” Minister Benoit Charette said in a memorandum to the Council of Ministers last June.
The proportion of Quebec lands that spread fertilizing residual materials could, however, “easily double [pour atteindre] 8 to 10%” if all possible materials were diverted from landfill sites, estimates the UPA’s general director. The new framework should come into force in November 2025, lifting the moratorium on the spreading of American biosolids, the Ministry predicts.
1. Read “Quebec imposes a temporary moratorium on the spreading of biosolids”
2. Consult the Ministry of the Environment’s draft framework
3. Read “Quebec wants to regulate the presence of eternal pollutants in “human manure””
Read “‘Eternal Pollutants’ in the Crosshairs of Many States”