London drinking water path

• Source & supply

  Lake Huron

  Lake Erie

  City of London owns and operates the local Drinking Water System (Class IV distribution / Class II treatment rating for city assets) with more than 2,100 km of pipes, reservoirs, and pumping stations. Regional boards supply bulk treated water; London is administering municipality for the Lake Huron board.

  London is unusual among large Ontario cities in blending two Great Lakes—Huron via Grand Bend and Erie via Port Stanley—into one municipal distribution system.

• Treatment

  Lake Huron Primary Water Supply System Water Treatment Plant

  Regional plant north of Grand Bend treating Lake Huron water for London and other member municipalities. Board-owned; OCWA-operated; capacity about 340 ML/day.

  Elgin Area Primary Water Supply System Water Treatment Plant

  Regional plant east of Port Stanley treating Lake Erie water. Board-owned; OCWA-operated; capacity about 91 ML/day. Water reaches London via the Elgin-Middlesex Pumping Station.

  Treatment on record: +1 more plant

• At the tap

  Hardness 100 mg/L (Moderate)

  Grade B (Good)

  pH 7.3 · lead 0.4 μg/L

  ECCC / municipal open data (seed)