Toronto drinking water path

Source

Lake Ontario Surface water

raw water

Intake

Raw water intake pump station

to plant

Treatment

R.C. Harris WTP filtration · +3 more plants

finished

Mains

Storage & mains Four plants feed 18 pumping stations, 11 underground reservoirs, four elevated tanks, roughly 540+ km of trunk watermains and 5,500+ km of distribution mains across six pressure zones (13 pressure districts). Also delivers water to southern York Region.

drinking water

Tap

Household tap Toronto

Source & supply
Lake Ontario
Four plants feed 18 pumping stations, 11 underground reservoirs, four elevated tanks, roughly 540+ km of trunk watermains and 5,500+ km of distribution mains across six pressure zones (13 pressure districts). Also delivers water to southern York Region.
Intakes sit one to five kilometres offshore deep in Lake Ontario; the Island plant’s treated water doubles as the cold source for downtown deep-lake cooling.
Treatment
R.C. Harris Water Treatment Plant
Largest Toronto plant (Queen Street East); conventional treatment, rated capacity 950,000 m³/day. Opened 1941; Art Deco complex often called the Palace of Purification.
R.L. Clark Water Treatment Plant
West-end plant at Twenty Third Street; rated capacity 615,000 m³/day.
F.J. Horgan Water Treatment Plant
At the tap
Hardness 157 mg/L (Hard)
Grade C (Fair)
pH 7.5 · lead 0.5 μg/L
ECCC / municipal open data (seed)