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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:
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Uni-directional
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.
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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.
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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.
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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.
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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.
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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.
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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.

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