PFAS drinking water rules in Ontario, the agency and citation behind them, how they compare to the Health Canada Objective of 30 nanograms per litre for the sum of 25 PFAS compounds, and the federal sites in Ontario where the Government of Canada has recorded PFAS as a contaminant of concern.
This is the Canada view of the North American PFAS dataset. The complete dataset, including all 3,452 US systems and 97 Canadian sites, lives on the main PFAS contamination map.
Guidance value only
No PFAS numeric standard was found in O. Reg. 169/03, and the Part XV.1 soil, ground water and sediment standards referenced by O. Reg. 153/04 contain no PFOA or PFOS entries. Ontario responds to PFAS through the Health Canada Objective and site-specific direction rather than a codified provincial number. Earlier versions of this tracker listed an interim ODWQS value and O. Reg. 153/04 PFOA and PFOS groundwater values. Neither could be located in the source documents and both were removed.
Compound
Limit (ng/L)
Note
Sum of 25 PFAS
30
Health Canada Objective, applied as guidance
O. Reg. 169/03 — Ontario Drinking Water Quality Standards
Health Canada Objective for PFAS in Drinking Water (2024)
Last reviewed 2026-08-13. Verify against the agency source before making a compliance or remediation decision.
From the Federal Contaminated Sites Inventory, ordered by federal priority classification. The inventory records which contaminants are present at each federal site, not the measured concentrations, so these entries show where PFAS has been identified rather than how much was found.
Custodian departments in Ontario: National Defence (7), MOT (6), Natural Resources Canada (1), Parks Canada Agency (1), dnd (1).
Site
Municipality
Custodian
Classification
Status
Media affected
North Bay
National Defence
High Priority for Action
Active
Groundwater, Soil, Surface water
Quinte West
National Defence
High Priority for Action
Active
Groundwater, Soil, Surface water
Fire Fighting Training Area #1
Adjala-Tosorontio
National Defence
High Priority for Action
Active
Groundwater, Soil, Surface water
Former Landfill - London Airport
London
MOT
High Priority for Action
Active
Groundwater, Sediment, Soil, Surface water
Thunder Bay
MOT
High Priority for Action
Active
Air, Groundwater, Surface water
Institute for Research in Construction, Carleton Place
Mississippi Mills
Natural Resources Canada
High Priority for Action
Active
Groundwater, Soil, Surface water
Quinte West
Parks Canada Agency
High Priority for Action
Active
Groundwater, Sediment, Soil, Surface soil
London Airport - Former Firefighting Training Areas
London
MOT
High Priority for Action
Active
Groundwater, Sediment, Soil, Surface water
Mtn View - Inner Landfill Site
Prince Edward County
National Defence
High Priority for Action
Active
Groundwater, Sediment, Soil, Surface water
Thunder Bay International Airport - Former Firefighting Training Area
Thunder Bay
MOT
High Priority for Action
Active
Groundwater, Sediment, Soil, Surface water
Petawawa
National Defence
Medium Priority for Action
Active
Groundwater, Surface soil
Sault Ste. Marie Airport - Former Firefighting Training Area
Sault Ste. Marie
MOT
Medium Priority for Action
Active
Groundwater, Sediment, Soil
Petroleum Contaminated Soil Pile
Adjala-Tosorontio
National Defence
Low Priority for Action
Active
Groundwater
South RV Compound and P-151 Compound Area
Essa
dnd
Low Priority for Action
Active
Groundwater, Soil
Transport Fleet Compound (O-95)
Essa
National Defence
Insufficient Information
Active
Groundwater, Soil
Port Colborne - Marine Emergency Duties Training Centre
Port Colborne
MOT
Not a Priority for Action
Active
Groundwater, Soil
Open the full map and filter Ontario pins
The map is built from the US EPA Fifth Unregulated Contaminant Monitoring Rule, a United States programme. Canada has no equivalent national monitoring dataset for PFAS in drinking water. Sampling is run by provincial regulators and individual utilities, and results are published in their own reporting. The regulatory detail above is compiled from the Ontario Ministry of the Environment, Conservation and Parks source listed in the citations.
Every count above is read straight from a published government file. Nothing is modelled, averaged, or estimated. The rules below are the exact rules used to produce the figures for Ontario.
Open the inventory source page
EPA UCMR 5 does not apply. UCMR 5 is a United States drinking water programme, so it produces no results for Ontario. No US figure is reused or scaled to stand in for Canadian data.
Which sites are listed. Inventory records whose province field is ON and that carry the PFAS contaminant code. That gives 16 sites in Ontario.
Site records, not samples. The inventory reports site status, classification, custodian, and affected media. It does not publish drinking water concentrations, so there is no Canadian equivalent of the US nanogram per litre figures.
Reporting lag. Custodian departments update their records on their own schedule, so a site may have progressed since it was last reported.
Limits and rules. The Ontario standard shown above comes from Ontario Ministry of the Environment, Conservation and Parks, No PFAS value in O. Reg. 169/03 or the Part XV.1 soil and groundwater standards, reviewed 2026-08-13.
If any figure on this page does not match its source file, tell Nelson and it will be corrected or removed.
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