Water Hardness by Town in the GTA and York Region
You already know your water is hard. Here is the official number for your town, straight from the region or city that runs your water, with a link to the report.
Find your town
How hard is your water?
Hardness as calcium carbonate, in mg/L and grains per gallon. On the USGS hardness scale cited by Health Canada, 61 to 120 mg/L is moderately hard, 121 to 180 is hard and over 180 is very hard. Town names that are links have their own page.
York Region
Toronto
| Town | mg/L | Grains per gallon | Rating | Source |
|---|---|---|---|---|
| Toronto, all of itLake Ontario | 119 | 7.0 | Moderately hard | City of Toronto, 2025 |
Peel Region
| Town | mg/L | Grains per gallon | Rating | Source |
|---|---|---|---|---|
| MississaugaLake Ontario | 125 | 7.3 | Hard | Peel Region, 2025 |
| BramptonLake Ontario | 125 | 7.3 | Hard | Peel Region, 2025 |
| Bolton and Mayfield West (Caledon)Lake Ontario | 125 | 7.3 | Hard | Peel Region, 2025 |
| Caledon Village and Mono MillsWells | 235 | 13.7 | Very hard | Peel Region, 2025 |
| Alton (Caledon)Wells | 325 | 19.0 | Very hard | Peel Region, 2025 |
| Caledon EastWells | 320 | 18.7 | Very hard | Peel Region, 2025 |
| Palgrave (Caledon)Wells | 245 | 14.3 | Very hard | Peel Region, 2025 |
| Cheltenham and Terra Cotta (Caledon)Wells | 415 | 24.3 | Very hard | Peel Region, 2025 |
| Inglewood (Caledon)Wells | 200 | 11.7 | Very hard | Peel Region, 2025 |
Halton Region
| Town | mg/L | Grains per gallon | Rating | Source |
|---|---|---|---|---|
| OakvilleLake Ontario | 124 | 7.3 | Hard | Halton Region, 2025 |
| BurlingtonLake Ontario | 124 | 7.3 | Hard | Halton Region, 2025 |
| Milton, lake-supplied areasLake Ontario | 126 | 7.4 | Hard | Halton Region, 2025 |
| Milton, well-supplied areasWells | 318 | 18.6 | Very hard | Halton Region, 2025 |
| Campbellville (Milton)Wells | 350 | 20.5 | Very hard | Halton Region, 2025 |
| Georgetown, lake-supplied areasLake Ontario | 125 | 7.3 | Hard | Halton Region, 2025 |
| Georgetown, well-supplied areasWells | 342 | 20.0 | Very hard | Halton Region, 2025 |
| Acton (Halton Hills)Wells | 324 | 18.9 | Very hard | Halton Region, 2025 |
Durham Region
| Town | mg/L | Grains per gallon | Rating | Source |
|---|---|---|---|---|
| PickeringLake Ontario | 125 | 7.3 | Hard | Durham Region |
| AjaxLake Ontario | 125 | 7.3 | Hard | Durham Region |
| Whitby and BrooklinLake Ontario | 125 | 7.3 | Hard | Durham Region |
| OshawaLake Ontario | 125 | 7.3 | Hard | Durham Region |
| Courtice, Bowmanville, Newcastle and NewtonvilleLake Ontario | 125 | 7.3 | Hard | Durham Region |
| Orono (Clarington)Wells | 309 | 18.1 | Very hard | Durham Region |
| UxbridgeWells | 186 | 10.9 | Very hard | Durham Region |
| Port PerryWells | 274 | 16.0 | Very hard | Durham Region |
| Greenbank (Scugog)Wells | 276 | 16.1 | Very hard | Durham Region |
| Blackstock (Scugog)Wells | 316 | 18.5 | Very hard | Durham Region |
| Beaverton (Brock)Lake Simcoe | 148 | 8.7 | Hard | Durham Region |
| Cannington (Brock)Wells | 312 | 18.2 | Very hard | Durham Region |
| Sunderland (Brock)Wells | 345 | 20.2 | Very hard | Durham Region |
Fix it
Hard water? Fix it today.
Buy a Canadian-made softener online with the install, or just the softener with free delivery in the GTA and Barrie. Not sure? We test your water at home for free.
On a private well? Your water is not in these tables. Start with well water testing.
Questions
Water hardness questions
Is GTA tap water hard? +
Yes, almost everywhere. Lake Ontario water, which supplies Toronto, Peel, Halton, southern York and the Durham lakeshore, comes in around 119 to 133 mg/L. On the USGS hardness scale, which Health Canada cites, 121 to 180 mg/L is hard, so most of the GTA sits in the hard band. Towns on wells are often well over 180 mg/L, which is very hard.
Why is well-supplied water so much harder? +
Groundwater sits in limestone and gravel and picks up calcium and magnesium on the way. That is why communities like Stouffville, Mount Albert, Caledon East, Acton and Cheltenham read two to three times harder than the lake-supplied cities next to them.
What do grains per gallon mean? +
It is the unit most softeners are set in. Divide mg/L by 17.1 to get grains per gallon. Water at 125 mg/L is about 7.3 grains per gallon.
Do I need a softener at these levels? +
If your water is hard or very hard, a softener stops the scale on fixtures, kettles, dishwashers and water heaters. We size it to your hardness and household, and read your hardness before and after the install so you see the difference.
Where do these numbers come from? +
From the region or city that runs your water system: York Region, the City of Toronto, Peel Region, Halton Region and Durham Region. Each row links the report it came from. Figures change a little from quarter to quarter, so we update them as new reports come out.
Where to go next
Next steps
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