Understanding Ajax's water
Ajax's water comes from Lake Ontario through the Ajax Water Supply Plant, which serves Ajax and Pickering and is connected to the Whitby and Oshawa plants.
Durham doesn't publish a hardness figure, but Lake Ontario water measured elsewhere in the GTA runs 119 to 130 mg/L (about 7 to 7.6 grains per gallon), which is hard. Expect similar water here, and confirm it with a free in-home test.
What the 2025 report shows
- Fluoride: added (0.12 to 0.85 mg/L at the Ajax plant in 2025)
- Free chlorine in the pipes: 0.16 to 5.00 mg/L
- Sodium: 16.7 to 20.9 mg/L
- Lead: 60 plumbing samples ranged from non-detect to 0.0018 mg/L in 2025, under the 0.01 mg/L limit
Source: Region of Durham, Oshawa/Whitby/Ajax Drinking Water System 2025 Annual Report.
Why Ajax homes treat their water
Ajax is almost entirely on municipal water, so the common complaints are the city-water ones: hardness and chlorine taste. The chlorine level in the Ajax distribution system ranged widely in 2025, which is why some homes notice it more than others.
Recommended water treatment for Ajax homes
We recommend systems based on where your water comes from. Your free in-home test confirms the fit before anything is installed.
Ajax homes on municipal water
Pickering Village, South Ajax, Central Ajax, Northwest Ajax, Nottingham, Riverside, Imagination, Mulberry Meadows, Audley
Softening for scale, carbon filtration for chlorine taste and smell, and reverse osmosis for drinking water. The Enhanced Water Softener handles the first two in one tank.
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Questions
How hard is Ajax water?
Durham Region doesn't publish a hardness figure for Ajax. Lake Ontario water elsewhere in the GTA measures 119 to 130 mg/L, which is hard. Our free in-home test measures your tap.
Does Ajax add fluoride to the water?
Yes. Durham's 2025 report shows fluoride added (0.12 to 0.85 mg/L at the Ajax plant in 2025).
Free in-home water test
Find out what's in your Ajax water
We test your water at your home, show you what's in it, and recommend the system that fits.
- Free
- About 30 minutes
- No obligation