Markham drinking water path

• Source & supply

  Lake Ontario

  York Region delivers purchased treated water through regional reservoirs and pumping stations; the City of Markham operates local watermains, valves, and hydrants to retail customers. Markham’s urban system is lake-based with no local raw-water plant.

  York Region states Markham, Vaughan, and Richmond Hill receive all municipal water from Lake Ontario via Toronto and Peel—unlike northern York communities that blend lake water with local wells or draw Lake Simcoe.

• Treatment

  City of Toronto and Region of Peel treatment plants (wholesale) — York Region supply

  Markham receives Lake Ontario water pre-treated by Toronto and Peel under long-term supply contracts. York Region owns the York Drinking Water System transmission, storage, and pumping that feeds Markham’s local distribution system.

• At the tap

  Hardness 229 mg/L (Very hard)

  Grade B (Good)

  pH 7.2 · lead 0.5 μg/L

  ECCC / municipal open data (seed)