Managing PFAS contamination in water: Canada's evolving approach
As concerns grow over PFAS — the so-called "forever chemicals" — Canada is advancing new policies, monitoring programs, and strategies to address contamination in drinking water and wastewater. This article explores Canada’s evolving response to this growing environmental and public health challenge.
Canada’s regulatory response to per- and polyfluoroalkyl substances (PFAS) has undergone significant evolution over the last decade. The federal government initially targeted individual PFAS substances such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), which were listed as toxic under the Canadian Environmental Protection Act, 1999 (CEPA), and subjected to restrictions on manufacture, import, and use.
However, growing scientific understanding of PFAS persistence, mobility, and cumulative risks led to a strategic shift. In March 2025, Environment and Climate Change Canada (ECCC) and Health Canada finalised their comprehensive State of Per- and Polyfluoroalkyl Substances (PFAS) Report. The report concluded that PFAS as a broad class meet CEPA’s toxicity criteria for potential harm to the environment and human health. This finding underpins Canada’s movement toward a class-based approach to regulation rather than a chemical-by-chemical strategy.
Canada is moving toward a class-based approach to regulating PFAS, rather than addressing each chemical individually as it has in the past
The class-based approach allows federal regulators to act on the full range of PFAS, including legacy compounds (e.g., PFOS, PFOA) and thousands of newer, replacement chemicals. This mirrors growing global scientific consensus that all PFAS share certain hazardous properties: extreme environmental persistence, widespread occurrence, and bioaccumulation potential in wildlife and humans.
In support of this regulatory strategy, the Government of Canada included all non-polymeric PFAS on Schedule 1 of CEPA (the List of Toxic Substances) in 2025. This listing provides broad legal authority to implement preventive measures across the full PFAS lifecycle, including new restrictions on manufacturing, product content, and environmental releases. For example, Canada has proposed updated controls on PFAS-containing firefighting foams, fluorinated surfactants, and industrial uses that may lead to environmental discharges.
Drinking water guidelines
In 2024, Health Canada published an objective for drinking water quality of 30 ng/L as a cumulative sum for 25 high-priority PFAS
Health Canada’s efforts to manage PFAS contamination in drinking water reflect this precautionary approach. In 2024, Health Canada published an updated objective for Canadian drinking water quality for PFAS. This objective recommends a treatment-based limit of 30 nanograms per litre (ng/L) as a cumulative sum for 25 high-priority PFAS. This guidance replaces earlier individual maximum acceptable concentrations set for PFOS and PFOA.
The 30 ng/L sum-of-25 objective was selected based on the technical feasibility of current treatment technologies, achievable detection limits, and the goal of minimising cumulative exposure. Although the guideline is not legally binding, it informs provincial regulators, municipalities, and utilities responsible for public water systems.
Wastewater policy
In parallel, policymakers have begun addressing the role of wastewater in PFAS contamination. Traditional wastewater treatment plants (WWTPs), designed primarily for nutrient removal and pathogen reduction, are generally unable to capture PFAS effectively. Consequently, PFAS discharged into wastewater enter receiving water bodies, sediments, and sludge.
The drinking water objective value is not legally binding, but informs provincial regulators, municipalities, and water utilities
While Canada has not yet established enforceable PFAS effluent standards for wastewater treatment facilities, this is recognised as a critical regulatory gap. The March 2025 State of PFAS Report recommends the development of discharge limits, PFAS monitoring requirements for wastewater plants, and national standards for PFAS levels in biosolids to prevent land-based contamination. The federal government is reviewing wastewater-specific regulations under CEPA and the Fisheries Act to address these pathways.
Provincially, British Columbia, Ontario, and Quebec have begun incorporating PFAS into their contaminated sites regulations and environmental quality guidelines for groundwater and biosolids management, but comprehensive wastewater discharge standards remain in development.
Monitoring programmes
While Canada has not yet established PFAS effluent standards for wastewater treatment facilities, this is recognised as a regulatory gap
Nationally coordinated monitoring of PFAS in drinking water has historically been limited. However, recent years have seen significant expansion in testing, particularly following Health Canada’s publication of its new PFAS objective.
In 2023-2024, ECCC and Health Canada initiated a targeted National Drinking Water Survey on PFAS, which sampled source water and treated drinking water from over 40 municipal systems across Canada. The survey found that PFAS were detectable in approximately 85% of systems tested, with total PFAS concentrations ranging from below detection limits to 25 ng/L.
Several provinces have conducted their own monitoring programs. Nova Scotia, Saskatchewan, and Ontario have implemented voluntary or pilot monitoring of drinking water systems since 2019, finding similarly low but widespread PFAS detections.
Drinking water monitoring efforts in municipal systems show widespread, low-level presence of PFAS in Canada’s water supplies
Wastewater surveillance of PFAS remains more limited but is expanding. In 2024, ECCC launched a National Wastewater PFAS Monitoring Initiative as part of the broader Chemicals Management Plan. Samples were collected from influent, effluent, and biosolids at 15 municipal WWTPs across Canada. Preliminary results indicate that PFAS are present in nearly all wastewater streams analysed. Effluent discharges commonly contained total PFAS in the range of 50 to 150 ng/L, significantly higher than typical drinking water concentrations.
Biosolids, often applied to agricultural land, contained total PFAS concentrations ranging from 200 to 900 µg/kg (dry weight). This creates concern about the long-term fate of PFAS in soils and potential leaching into groundwater. Several provinces are now considering restrictions or enhanced monitoring requirements for biosolids land application.
Cleanup and remediation initiatives
The federal government manages a portfolio of over 20,000 contaminated sites across Canada, many of which are located at military bases, airports, and firefighting training facilities where PFAS-containing aqueous film-forming foams (AFFFs) were historically used.
Through the Federal Contaminated Sites Action Plan (FCSAP), renewed in 2020, Canada has prioritized PFAS remediation projects. As of 2025, over 130 federal sites have confirmed or suspected PFAS contamination. Cleanup efforts focus on containing PFAS plumes, installing groundwater extraction and treatment systems, and isolating contaminated soils.
Biosolids, often applied to agricultural land, contained total PFAS concentrations ranging from 200 to 900 µg/kg (dry weight)
Where groundwater contamination threatens public water supplies, local authorities have installed point-of-entry filtration systems, provided alternative drinking water supplies, or initiated full-scale remediation projects. In some Indigenous communities affected by PFAS-contaminated firefighting foam releases, temporary bottled water supplies have been provided while long-term treatment solutions are implemented.
Some larger WWTPs in Canada have initiated pilot projects to explore PFAS removal technologies, including advanced oxidation, foam fractionation, and electrochemical destruction. However, these technologies remain expensive and are not yet widely deployed. At present, most wastewater systems lack full-scale PFAS treatment, allowing continuous low-level discharge into receiving waters. Recognising this issue, ECCC and several provinces are evaluating the feasibility of requiring PFAS pretreatment from industrial dischargers, tighter biosolids management controls, and eventual PFAS removal requirements for municipal WWTPs.
Canada in the global context: comparing PFAS water policies
At present, most wastewater systems lack full-scale PFAS treatment, allowing continuous low-level discharge into receiving waters
Canada’s regulatory trajectory on PFAS increasingly parallels U.S. actions but with some important differences. In April 2024, the U.S. Environmental Protection Agency (EPA) set limits for five individual PFAS in drinking water. The enforceable Maximum Contaminant Levels (MCLs) for PFOA and PFOS are 4 ng/L (ppt) each, and for PFNA, PFHxS, and GenX chemicals, the MCLs are 10 ng/L each. In addition, when two or more of PFNA, PFHxS, GenX chemicals, and PFBS are present together, a hazard index is applied to account for their combined health risks. However, in May 2025 the EPA announced its intent to rescind the regulations and reconsider the regulatory determinations for PFNA, PFHxS, GenX, and the hazard index mixture that includes these three substances plus PFBS. Furthermore, the U.S. has taken aggressive steps on PFAS under its Superfund program, designating PFOA and PFOS as hazardous substances in 2024 under CERCLA, which triggers strict cleanup requirements.
The U.S. standards are numerically more stringent than Canada’s 30 ng/L sum-of-25 objective, though Canada’s approach covers a broader set of PFAS compounds collectively. Canada is closely monitoring U.S. developments and may revise its objectives further based on emerging science and treatment capabilities.
The European Union adopted new Drinking Water Directive standards in 2020, setting a 100 ng/L limit for the sum of 20 PFAS and a 500 ng/L limit for total PFAS, with full implementation required by 2026. In 2023, the EU finalised the common monitoring list, defining exactly which 20 PFAS are included in the 100 ng/L sum parameter. Canada’s 30 ng/L objective is more protective than the EU standard in numerical terms, but not yet legally binding.
The EU is advancing a broad REACH restriction proposal that would phase out most non-essential uses of PFAS across consumer products and industrial applications. Canada’s class-based CEPA listing offers similar flexibility for future product controls but remains under policy development.
International organisations such as the OECD and UNEP continue to promote global PFAS phase-outs. Canada ratified the Stockholm Convention amendments listing PFOS, PFOA, PFHxS, and related chemicals for elimination, consistent with its domestic restrictions.
In summary, Canada’s PFAS strategy is broadly aligned with international best practices while tailoring regulatory measures to domestic capacities. The combination of class-based regulation, precautionary drinking water objectives, expanded monitoring, and growing investment in wastewater and remediation solutions reflects a comprehensive but still evolving national approach.