Adding PFAS to toxic substances list won't necessarily lead to stricter guidelines for drinking water

A class of chemicals called per- and polyfluoroalkyl substances (PFAS) could be added to Canada's list of toxic substances, but it's unlikely to have an immediate effect on communities already contaminated with the "forever chemicals," such as North Bay, Ont. 

In early March, Environment and Climate Change Canada announced it would move to add PFAS to the country's official toxic substances list.

Because they don't break down easily and are great at repelling water, PFAS are found in a number of everyday products including outdoor clothing, non-stick pans, cosmetics and even some food packaging.

Cassie Barker, the senior program manager at Environmental Defence for toxics, says certain types of PFAS have been found to harm the kidneys and immune system.

"It harms the endocrine system," she said. "The basic building blocks of your body are being interfered with by very small levels of PFAS."

In North Bay, the Department of National Defence (DND) conducted firefighting training exercises from the early 1970s to the mid-1990s at the city's Jack Garland Airport with aqueous film-forming foams that contain PFAS.

Over that time, the foams seeped into groundwater and contaminated wells and Trout Lake, the source of drinking water for the city of 52,000. 

Ontario's Ministry of the Environment has an interim advice value, or recommendation, for PFAS in drinking water that is 70 nanograms per litre. Those values are based on guidelines from Health Canada and are equivalent to 3.5 drops in an Olympic-sized swimming pool. 

The ministry tests Trout Lake for 11 substances that fall within the PFAS family and in 2023 the average measurement for those chemicals was 56 nanograms per litre.

Toxic substances list opens door for regulations

If PFAS are added to Canada's toxic substances list, though, it would not result in any immediate changes to regulations. 

"Adding a substance to Schedule 1 of CEPA ( Canadian Environmental Protection Act) does not in and of itself restrict or prohibit the substance; rather, it enables risk management instruments to be developed such as regulations under the Act," Environment Canada said in an email to CBC News.

Environment Canada has published a proposed risk management plan for PFAS, which could lead to banning the use of PFAS in consumer products and firefighting foams.

That would reduce any future PFAS contamination into the environment, but would not affect drinking water standards, as those are managed by Health Canada.

Stricter drinking water guidelines

Last summer, Health Canada updated its objective value for the sum concentration of 25 types of PFAS in drinking water to 30 nanograms per litre. North Bay's measurements from 2023 exceed that.

As the provincial regulator, Ontario's Ministry of the Environment said it is currently "reviewing the basis of Health Canada's new objective and will assess the applicability for its use in Ontario and the best way to implement it."

In the meantime, North Bay has been working with DND on a $20-million plan to remediate the site at the airport where PFAS seeped into the environment. 

City spokesperson Gord Young said they've removed 23,000 tonnes of contaminated soil from the site so far.

"Adsorptive material is also being injected at excavated hot spots, with this phase expected to be completed by early May," Young said in an email to CBC News.

Young said the next phase of the cleanup will be to add underground barriers to keep water from seeping out of the area. That work is scheduled to start in early 2026.