By Ruby Pratka
Local Journalism Initiative
The municipality of Farnham has ordered further tests after higher-than-expected levels of per- and polyfluoroalkylates – more commonly known as PFAS or “forever chemicals” – were found in residue from the town’s water treatment plant.
Water treatment residue, also called sewage sludge or biosolids, is sometimes used as fertilizer for large-scale farming operations, in place of chemical fertilizer or manure. In March, Quebec’s environment ministry imposed PFAS concentration limits for biosolids, beyond which they could not be used for fertilizer. The new norms are scheduled to take effect in November. “When the Quebec government announced new standards [for PFAS levels], we could have waited a year [to test the biosolids], but I’ve always believed you need to be proactive for things like that,” Farnham Mayor Patrick Melchior told the BCN. “It turns out we’re higher than normal. We’ve ordered other tests and we should have the results from one day to the next.”
The town’s priorities are now to find out where the elevated levels are coming from and keep further PFAS contamination from leaching into the town’s drinking water, which is drawn from the Yamaska River, Melchior said. He emphasized that the levels detected were not threatening to human or plant health, but “we need to find out where it’s coming from to keep it from getting in the water. We need to take time to do things right.”
Melchior said local farmers and the Quebec Ministry of Environment, the Fight against Climate Change, Wildlife and Parks (MELCCFP) were contacted as soon as the higher PFAS levels were detected. “There have been discussions with [the environment ministry] and they have assured us of their support – they have to help us find a way.”
PFAS have been used for decades in fire retardants, antiadhesive coatings, food wrapping and some cosmetics, to make materials waterproof, stainproof or fire-resistant. According to Health Canada, prolonged PFAS exposure may affect a person’s liver, kidney and thyroid function; metabolism; and immune response. While many once-common uses of PFAS have been phased out since their health effects became apparent, the substances are notoriously hard to break down, hence the name “forever chemicals.”
“Once they’re there, they’re there, although maybe future scientific research will find a way” to remove PFAS from groundwater, Melchior said.
The fact that the chemicals have been so common also makes their sources hard to pinpoint. Farnham is home to a decommissioned military base, and outdated Cold War-era chemical storage practices at CFB Valcartier, near Quebec City, were linked to the contamination of groundwater in a nearby municipality. However, it’s far from clear that the elevated PFAS levels in Farnham are linked to the base. As Melchior pointed out, “these chemicals are in lots of things.” A worldwide study, published in 2024 in the journal Nature Geoscience, found that they were present in 31 per cent of groundwater samples.
“We will investigate, and all parties need to get involved, because this concerns everybody,” the mayor said.
The Department of National Defence (DND) and the MELCCFP could not comment by the BCN’s deadline, although a DND spokesperson said a response would be provided at a later date.