Toronto Water is the municipal division of the City of Toronto under Infrastructure and Development Services responsible for the water supply network, and stormwater and wastewater management in Toronto, Ontario, Canada, as well as parts of Peel and York Regions.
History Early days Water treatment was originally established in order to provide safe drinking water. In the 19th century, the water off the city's shores was severely polluted by the dumping of waste from residences and businesses.
Before 1842, Toronto's water supply was manually pumped from Lake Ontario, streams and wells. Water carters would take the water and distribute it to customers across the city.
Private water supply From 1843 to 1873, water was privately provided by Furniss Works or Toronto Water Works, a subsidiary of Toronto Gas Light and Water Company, which was owned by Montreal businessman Albert Furniss.The Culture of Flushing: A Social and Legal History of Sewage, p 66
Following Furniss's death in 1872, the City of Toronto bought out Furniss Works and transformed the water supply to public hands under the Toronto Water Works Commission.
Suburban water supply Outside of the pre-amalgamation City of Toronto each of the former municipalities had its own treatment plants and pumping stations. North York had three, one at Oriole, which was built in the 1923, the ruins of pumping station found near Duncan Mills Rd and Don Mills Rd, Steeles built in the 1930s, and Sheppard West built in the 1940s. Scarborough had one built in 1921 and New Toronto had one built in 1924. Prior to the 1950s, the municipalities were responsible for water treatment and water came from local water sources like wells and streams.
Metro Toronto The current system was introduced in the mid-1950s, with the formation of Metro Toronto in 1954, and was managed by Metro Toronto. Since 1975, Toronto has supplied water to York Region (mostly to residents in the south end of York).
City of Toronto Following amalgamation in 1998, Toronto Water was created from the Toronto Works and Emergency Services and once part of Metro Toronto Works department.
As of April 2005, the departments and commissioners were replaced by divisions under the City Manager (and Deputy Managers). Toronto Water is now under the Toronto Water Division.
Drinking water operations Treatment process Water pumped from Lake Ontario is treated via conventional drinking water treatment processes:
Pre-chlorination Flocculation and sedimentation Filtration Chlorination Chloramination, prior to distribution
Treatment plants The City of Toronto uses four water treatment plants, all of which are located next to and get their water from Lake Ontario: +NameOpenedLocationCapacityR.C. Harris Water Treatment Plant1941Island Water Treatment Plant1977 F. J. Horgan Water Treatment Plant1979R. L. Clark Water Treatment Plant1968
R.C. Harris Water Treatment Plant
The R. C. Harris Water Treatment Plant is located east of Old Toronto at the eastern end of Queen St East and the foot of Victoria Park Ave at Lake Ontario. It is the oldest of the operational water treatment plants in Toronto, being opened on November 1, 1941 after construction started in 1932. The plant has a capacity of 950 million litres per day (250 million US gallons per day) and produces approximately 30% of Toronto's drinking water. The intakes are located over from shore in of water, running through two pipes under the bed of the lake.
Prior to the construction of the water treatment plant, the area was the site of Victoria Park, a waterfront amusement park that operated from 1878 until 1906, and then the site was used by the Victoria Park Forest School until construction started in 1932. The plant is named after Roland Caldwell Harris, who was the Public Works Commissioner from 1912 to 1945. He was involved in projects including the Prince Edward Viaduct, the Mount Pleasant bridge, and the expansion of the Toronto Civic Railways' streetcar network. Known for its Art Deco style, the building is dubbed “The Palace of Purification” and was designated under the Ontario Heritage Act in 1998.
Island Water Treatment Plant The Island Water Treatment Plant is located on the Toronto Islands. The plant was opened in 1977 with a capacity of . The plant produces approximately 20% of Toronto's drinking water. The plant sits on the site of the first water treatment plant in Toronto, which was built in the 1900s and is no longer in service. The cold, treated water produced by the plant passes through a heat exchange system, which enables Enwave's Deep Lake Water Cooling project to cool buildings across the harbour in Downtown Toronto.
F. J. Horgan Water Treatment Plant
The F. J. Horgan Water Treatment Plant is located in Scarborough in the West Hill neighbourhood on Lake Ontario. It is the newest of Toronto's water treatment plants, being opened in 1979. With a capacity of , it provides water to customers in the east end and York Region. The plant produces approximately 20% of Toronto's drinking water. The plant is named after Frank J. Horgan, the Commissioner of Works for Metro Toronto from 1980 to 1989.
In 2009, the plant was expanded by Alberici in a contract. The expansion included the construction of a new building with three ozone tanks, five filter boxes, and two backwash surge tanks. As of 2022, it remains the only plant in Toronto that uses ozone as the primary disinfectant to control pathogens, seasonal taste, and odour. The plant features a green roof and a 10-megawatt standby power plant to meet demand in the event of a power outage.
R. L. Clark Water Treatment Plant The R. L. Clark Water Treatment Plant is located in Etobicoke in New Toronto on Lake Ontario. The plant was opened on November 22, 1968. It has a capacity of and produces approximately 30% of Toronto's drinking water. The plant was originally called the Westerly Plant, but it was later named after Ross Leopold Clark, the Commissioner of Works for Metropolitan Toronto from 1956 to 1979. The plant replaced the New Toronto Filtration Plant, which was opened in 1915.
Distribution
The drinking water distribution system operated by Toronto Water comprises 6 pressure zones and approximately 520 km of watermains (greater than 150 mm in diameter).
Pumping stations are located across the city to pump water from the filtration plants to residences. They are particularly critical since the city gains in elevation as it moves northwards away from Lake Ontario. Some pumping stations are located outside the city.
The City of Toronto operates 18 water pumping stations as of 2014:
Pumping Station Location ReservoirCity Kennedy Pumping Station South of Steeles Ave E on Kennedy Rd—Toronto W.H. Johnston Pumping Station Lawrence Ave W and Royal York Rd — Armour Heights Pumping Station Wilson Ave west of Avenue Rd— West Toronto Pumping Station South of Davenport Rd on Old Weston Rd — St. Albans Pumping Station Aukland Rd and St. Albans Rd, across from Kipling Station— Lawrence Pumping Station Lawrence Ave W and Caledonia Rd Lawrence Reservoir Richview Pumping Station North of Eglinton Ave W on Martin Grove Rd Richview Reservoir High Level Pumping Station Poplar Plains Rd, north of Dupont St and Davenport Rd — Keele Pumping Station South of Steeles Ave W on Keele StKeele Reservoir Ellesmere Pumping Station Ellesmere Rd west of Morningside AveEllesmere Reservoir Eglinton Pumping Station Ashtonbee Rd and Pharmacy Ave Eglinton Reservoir Parkdale Pumping Station The Queensway east of Parkside Dr — Rosehill Pumping Station Mount Pleasant Rd and Carstowe RdRosehill Reservoir Scarborough Pumping Station Fishleigh Drive, south of Danforth Ave E and Kingston Rd — John St Pumping Station Lake Shore Boulevard W and Rees St—Bayview Pumping StationSouth of Highway 407 on Bayview AveBayview ReservoirMarkhamMilliken Pumping StationEast of Kennedy Rd on 14th AveMilliken ReservoirThornhill Pumping StationGreen Lane and Bayview Ave—
Storage Toronto water stores water in three formats: Floating reservoir: Newer Water tower or older Water tank with limited capacity. Ground level reservoir: Underground water storage with grass covered top with large capacity. Temporary storage: Stored at a water treatment plant with limited capacity.
Water in the city is stored once it is treated, ensuring uninterrupted water supply.
There are 4 water towers located in the city. They are mainly located in areas that cannot accommodate underground reservoirs due to space restrictions.
Name Location Whitlam Tank Lake Shore Boulevard E Leslie Tank Leslie St and Lawrence Ave E at Talwood Drive Rouge Tank Sheppard Ave E near Morningside Ave Warden Tank Warden Ave and Civic Rd
There are 10 underground reservoirs across Toronto and in Markham:
Name Above ground LocationCityRef. Eglinton Reservoir Ashtonbee Reservoir Park Pharmacy Ave north of Eglinton Ave EToronto Ellesmere Reservoir Ellesmere Reservoir Park East of Neilson Rd and Ellesmere Rd Keele Reservoir Keele Reservoir Park South of Steeles Ave W and Keele StLawrence ReservoirCaledonia ParkLawrence Ave W and Caledonia Rd Rosehill Reservoir David A. Balfour Park Avoca Ave and St. Clair Ave E Richview Reservoir Richview Park Martin Grove Rd and Eglinton Ave W St. Clair Reservoir Sir Winston Churchill Park Spadina Rd and St. Clair Ave W Milliken Reservoir Milliken Mills Park East of 14th Ave and Kennedy RdMarkhamMaple ReservoirMaple Reservoir ParkSouth of Teston Rd and Keele StNorth Markham ReservoirGrass-covered propertyMcCowan Rd and Stouffville SideroadBayview ReservoirBayview Reservoir ParkSouth of Highway 407 on Bayview Ave Dufferin Reservoir Grass-covered property Dufferin St and Autumn Hill BlvdVaughan
There are in-plant temporary storage tanks storing water as well:
Name Capacity F. J. Horgan Water Treatment Plant Island Water Treatment Plant R. C. Harris Water Treatment Plant R. L. Clark Water Treatment Plant Scarborough Pumping Station
Wastewater treatment
Treatment process Toronto's wastewater treatment plants treat wastewater in a 5 step process:
Screening Git removal Primary treatment Secondary treatment Disinfection
During screening, large objects such as rocks and sticks that get washed into the sewer system are removed. Git removal removes smaller objects like tampons, dental floss, and wipes. Primary treatment separates human waste from wastewater. Secondary treatment uses microscopic organisms to reduce and convert pollutants in the wastewater. This stage also removes nitrogen and phosphorus from the wastewater. Disinfection destroys any remaining harmful pathogens. After disinfection, the effluent wastewater meets all Ministry standards and is returned to the natural environment and reused within the facility for internal process use.
Solids removed during primary treatment and secondary treatment are pumped into digesters which allow a biological process that uses microorganisms, heat, mixing, and a 10-20 day holding time to break down complex organic matter into simpler forms. This produces methane as a byproduct. This produces biosolids, which are rich in organic material and nutrients.
Treatment plants The City of Toronto has four facilities that process wastewater before it is returned to the lake: +NameOpenedLocationCapacityAshbridges Bay Wastewater Treatment Plant1910North Toronto Wastewater Treatment Plant1929Highland Creek Wastewater Treatment Plant1956Humber Wastewater Treatment Plant 1960
Ashbridges Bay Wastewater Treatment Plant
The Ashbridges Bay Wastewater Treatment Plant is located on the east end of the Port Lands, south of the intersection of Leslie St and Lake Shore Blvd East along Lake Ontario. The plant has a capacity of , serving a population of 1.5 million. The plant began operation in 1917 and was originally called the Main Treatment Plant.
North Toronto Wastewater Treatment Plant