Improving the system
Toronto Water's goal is to ensure high water quality while protecting public health and safety and the environment. This goal is backed by the City's various improvement projects and continual inspection and maintenance of storm, sanitary and combined sewer pipes. Activities include:
Watermain flushing
Staff select and open certain fire hydrants and watermain valves to flush rust deposits from the line. Staff move a high volume of water very quickly through the pipes. Its force scours and cleans the system. Flushing the watermains alleviates residents' complaints of rusty water (red water), helps maintain the highest water quality and improves the pipes' hydraulic capacity.
Closed circuit television inspection of municipal sewers
By using a remote controlled closed circuit television (CCTV) cameral equipment, city staff is able to inspect municipal sanitary, storm and combined sewer systems. The CCTV helps us assess the sewer system's hydraulics and structural condition. It provides digital information that helps us to determine maintenance and rehabilitation needs.
Stormwater quality investigation
Home improvement projects sometime result in pipes being connected to the wrong system. That's why dye strips are placed in an indoor plumbing fixture, such as a toilet, and then flushed. The purpose is to check that sanitary flows are not entering the storm sewer system where they would be discharged to the lake, rivers or creeks. If the dye from the toilet shows up in the storm sewer, we ask homeowners to have the pipes reconnected to the appropriate sanitary system.
Sewage flow monitoring
A gauge is placed in a sanitary sewer to record the flow of wastewater on a continuous basis. Measuring the flow in certain sewers helps us pinpoint high-flooding occurrences, the system's characteristics and need for any remedial work or upgrades. The City tries to eliminate problem areas by identifying and removing sources of infiltration, stormwater and physical restrictions that could affect flow in the sewer. This activity reduces the need to expand our sewer system, saves capital dollars and helps reduce the number of basement floodings during rain events.
Infiltration inflow program
In 2002, the City began a three-year program to identify sources of stormwater entering the sanitary sewer system that may lead to basement flooding. City staff puts a harmless dye product into downspouts, catchbasins or area drains. Discharged dye traced to a municipal sanitary sewer system informs us that the fixture is improperly connected. Disconnecting downspouts and other fixtures that collect storm runoff, found connected to the sanitary sewer system, lessens the chances of basement flooding.
No-dig sewer rehabilitation project
To keep our sewer system in top form, the City has begun using a No-dig sewer rehabilitation process. As the name implies, a new method of construction called 'trenchless' technology is being used. Gone is the old 'open-cut' method where roads were dug up and traffic jams were commonplace. Instead, with the No-dig system you can slipline, drill, repair, install, or do what has to be done to the sewer pipe, by using existing maintenance holes without digging up the entire road. The No-dig approach also means lower construction costs, less traffic and road restoration delays, and it minimizes the construction impact on communities and the environment.
Watermain rehabilitation program
Red water, low water pressure and reduced water flow and water quality issues are some of the problems cities deal with when it comes to aging watermains. That's why our city has an annual watermain rehabilitation program. Where possible, this program uses the No-Dig technique to lower costs, and minimize the disruption to city's residents and businesses. For the most part, our aging watermains are structurally sound but need to be cleaned and lined and this is done through excavation pits. Once the pipe is cleaned, we spray a cement mortar inside, protecting the pipe from everyday wear and tear and corrosion. If a watermain pipe is structurally vulnerable, then the City uses the traditional 'open-cut' approach where roads are dug up and a new pipe is installed. Right now the City is also testing other, less disruptive techniques for watermain pipe replacements for possible future use. The city has 4600 km of watermain pipes and each year it rehabilitates approximately 100 km.