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Our water treatment facilities have a water quality laboratory, staffed by qualified lab technologists. They work closely with the system operators to monitor the quality of water. We collect samples regularly and analyze them to ensure the safety and integrity of the drinking water system.
Fluoride is not added to City of St. John's drinking water.
The City of St. John's has three water treatment facilities:
Windsor Lake Water Treatment Facility
The Windsor Lake Water Treatment Facility treats raw water collected from the Broad Cove River and Windsor Lake watersheds. The Little Powers Pond Pump Station pumps raw water from the Little Powers Pond watershed and transfers it into Windsor Lake. Raw water is then taken from Windsor Lake and pumped up to the Main Treatment Building via the Low Lift Pump Station.
The treatment process consists of:
- screening
- membrane microfiltration
- UV disinfection
- chlorine disinfection
- alkalinity enhancement using hydrated lime and carbon dioxide
The rated capacity of Windsor Lake is 70,000 cubic metres per day in the summer and 53,500 cubic metres per day in the winter. The difference in capacity over the seasons is due to the viscosity changes in water as it gets colder.
Bay Bulls Big Pond Water Treatment Facility
The Bay Bulls Big Pond Water Treatment Facility collects raw water from Bay Bulls Big Pond and pumps it to the Main Treatment Building via the Low Lift Pump Station. The treatment process consists of:
- screening
- pH adjustment and alkalinity enhancement using hydrated lime and carbon dioxide for pre-treatment
- coagulation
- flocculation
- dissolved air floatation (DAF)
- filtration through rapid gravity dual media filters
- UV disinfection
- chloramine disinfection using ammonia and chlorine
- pH adjustment and alkalinity enhancement using hydrated lime and carbon dioxide for distribution system corrosion control
The rated capacity of Bay Bulls Big Pond is 85,000 cubic metres per day.
Petty Harbour Long Pond Water Treatment Facility
Petty Harbour Long Pond Water Treatment Facility is the City's newest water treatment plant. The treatment process consists of:
- screening
- pH adjustment and alkalinity enhancement using hydrated lime and carbon dioxide for pre-treatment
- coagulation
- flocculation
- dissolved air flotation (DAF)
- filtration through rapid gravity dual media filters
- UV disinfection
- chlorine disinfection
- pH adjustment and alkalinity enhancement using hydrated lime and carbon dioxide for distribution system corrosion control
The rated capacity of Petty Harbour Long Pond is 14,500 cubic meters per day.
Water Reservoirs
Our water reservoirs store treated water before it goes to the municipal distribution system. Water reservoirs must be capable of providing adequate flow and pressure for domestic, commercial, and industrial use. They must also store water during periods of low demand, provide water during short power outages and provide a reserve of water for fire suppression and other emergencies.
- Kenmount Hill Reservoirs: 17,300 m3 (17,300,000 L)
- Jensen Camp Reservoir: 11,500 m3 (11,500,000 L)
- Southlands Reservoirs: 19,600 m3 (19,600,000 L)
- Galway Reservoir: 7,500 m3 (7,500,000 L)
- Windsor Lake WTP Reservoir: 20,000 m3 (20,000,000 L)
- Autumn Drive Reservoir: 8,000 m3 (8,000,000 L)
- Petty Harbour Long Pond WTP Reservoir: 10,000 m3 (10,000,000 L)
- Shea Heights Reservoir: 2,350 m3 (2,350,000 L)
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