Understanding Whitby's water
Whitby's water comes from Lake Ontario, treated at the Whitby Water Supply Plant and the Oshawa plant. Both feed one connected system that also serves Brooklin, Oshawa, Ajax, Pickering and Courtice.
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 1.54 mg/L at the Whitby plant in 2025)
- Free chlorine in the pipes: 0.48 to 2.75 mg/L
- Sodium: 13.9 to 20.6 mg/L
- Lead: 76 plumbing samples ranged from non-detect to 0.0024 mg/L in 2025, well under the 0.01 mg/L limit
Source: Region of Durham, Oshawa/Whitby/Ajax Drinking Water System 2025 Annual Report.
Why Whitby homes treat their water
Whitby's newer neighbourhoods, from Brooklin to Taunton North, are full of family homes with high water use: a big water heater, a dishwasher and an ensuite or two. That's exactly where hard-water scale costs the most.
Recommended water treatment for Whitby homes
We recommend systems based on where your water comes from. Your free in-home test confirms the fit before anything is installed.
Whitby homes on municipal water
Downtown Whitby, Port Whitby, Brooklin, Williamsburg, Taunton North, Rolling Acres, Pringle Creek, Blue Grass Meadows, Lynde Creek
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.
Homes on private wells
Ashburn, Myrtle, Myrtle Station and the rural north of Whitby
Private wells need their own plan: iron and manganese removal, softening, tannin treatment if the water is tea-coloured, and UV disinfection for bacteria.
Iron & Manganese Filter
Birm media removes iron, manganese and the orange or black stains they leave.
See Iron & Manganese Filter
SoftBlu Water Softener
High-capacity softener that stops scale on fixtures, kettles and appliances.
See SoftBlu Water Softener
UV Pro
Ultraviolet disinfection for well water: bacteria, viruses and cysts.
See UV Pro
Tannin Eliminator
Clears tea-coloured water and yellow stains caused by tannins.
See Tannin EliminatorPopular in Whitby
Nearby areas we also serve
Questions
How hard is Whitby water?
Durham Region doesn't publish a hardness figure for Whitby. 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 Whitby add fluoride to the water?
Yes. Durham's 2025 report shows fluoride added (0.12 to 1.54 mg/L at the Whitby plant in 2025).
Is there free well water testing in Whitby?
Yes. Durham Region Health Department tests private well water for bacteria for free. Pick up a bottle at a Region service location. Our in-home test covers iron, hardness and other minerals.
Free in-home water test
Find out what's in your Whitby 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