Understanding Markham's water
Source: York Region, average hardness Q2 2026.
Where does Markham's water come from?
Markham is part of York Region, which buys its water from the City of Toronto and the Region of Peel, treated at Lake Ontario plants. Some rural areas in north and east Markham rely on private wells. Homes in Markham may see:
- Hard water (York Region average 126 mg/L)
- Chlorine taste or odour on city water
- Iron and manganese staining in well areas
- Tannins in rural groundwater
Not sure whether you're on city or well water? We'll check during your free consultation.
Recommended water treatment for Markham homes
We recommend systems based on where your water comes from. Your free in-home test confirms the fit before anything is installed.
Homes on city water
Unionville, Milliken, Cornell, Greensborough, Markham Village, Thornhill
Softening, chlorine filtration and reverse osmosis cover most Markham homes.
Homes on well water
Rural north and east Markham, near Highway 48
Well homes need iron or tannin treatment, depending on the test, plus UV disinfection.
Iron & Manganese Filter
Birm media removes iron, manganese and the orange or black stains they leave.
See Iron & Manganese Filter
Tannin Eliminator
Clears tea-coloured water and yellow stains caused by tannins.
See Tannin Eliminator
UV Pro
Ultraviolet disinfection for well water: bacteria, viruses and cysts.
See UV ProSigns you may need a water filter
- Foul taste or chlorine odour
- Yellow or orange staining in toilets and sinks
- Cloudy or rusty water
- Dry, itchy skin after bathing
- Appliances breaking down early
Nearby cities we also serve
Questions
How hard is Markham water?
York Region reported an average of 126 mg/L (about 7.4 grains per gallon) in Q2 2026.
Is all of Markham on city water?
Most of it is. Some rural properties in north and east Markham use private wells.
Free in-home water test
Find out what's in your Markham 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