What is unidirectional water main flushing?
Unidirectional flushing is
a method of cleaning water mains through a network of flushing sequences with
the water being discharged from a fire hydrant. This program will involve
closing valves in a specific sequence to create water movement in one direction
while opening specific hydrants at the end of each sequence. This type of
flushing increases the speed of the water flow in the water main, which
produces a scouring action and the removal of sediment deposits. The flushing
starts at a clean water source (a Water Tower) and moves towards the outer
limits of the Town. This ensures that clean water is always used to flush the
mains.
What is conventional water main flushing?
In conventional flushing,
the water used to flush the main does not always begin at the clean water
source (such as the water treatment plant) and the speed of the water is
much lower than during unidirectional flushing. As a result, more water is
required to thoroughly clean the water mains.
Are there other benefits to using the unidirectional flushing technique?
Yes, in addition to
removing more sediment and using less water than conventional flushing,
unidirectional flushing tests and exercises the water system valves and
hydrants.
When will you flush the water mains?
We will flush water mains
in different areas of the Town each year, starting in May and ending in October
from 7 a.m. to 3:30 p.m., Monday to Friday.
How long does it take to flush the water mains on each street?
It takes about 30 to 60
minutes to flush the water mains on each street. After the flushing, the water
can be cloudy for up to four hours.
How will I know when you are cleaning the water mains on my street?
You will notice our
flushing vehicles in your neighbourhood as well as flushing warning signs where
they are flushing.
How will I be affected during the hydrant flushing program?
You probably will not even
be aware that flushing is taking place in your neighbourhood. Flushing is
generally conducted between 7 a.m. and 3:30 p.m., Monday through Friday. Select
hydrants will be opened for water pipe flushing. While the hydrants are open,
the residents in the neighbourhood may experience discoloured water or a small
drop in water pressure, however, your water service should not be interrupted.
If you have no water pressure, please notify Water and Wastewater Services at 705 526 4275 ext. 4207.
Can I use my water when you are flushing the water mains in my neighbourhood?
When you see flushing being
carried out on your street, you should avoid using water for any purposes that
require clean water, such as laundry. You should also avoid using your hot
water system to minimize the amount of sediment drawn into your hot water tank.
Will I notice anything different about my water after you have cleaned the water mains?
Water is sometimes discoloured, milky or cloudy looking or has a chlorine smell after water main cleaning, but this should not last long.
Discoloured Water
The flushing process is designed to clean the water mains and will cause discoloured water, but this should not last long. You should avoid laundering clothing to minimize staining.
Cloudy Water
Water is cloudy when air gets in it and makes tiny bubbles. These bubbles are harmless and will disappear if you let the water sit for a few minutes.
How can I clear up the water?
- Turn on a cold water tap and let the water run for a few minutes, we recommend using the cold-water faucet on a bathtub.
- Catch some water in a light-coloured cup or container to see if it is clear. You can use your water if it is clear.
- If the water does not clear in 15 minutes, wait 30 minutes and try again.
What should I do if the water is still discoloured after three to four hours?
If this happens, please
call 705 526 4275 ext. 4207 and a Town representative will contact you.
Why can't you clean the water mains at night?
It is safer for staff to
work on the streets in daylight. Also, it is easier in the daylight to see when
all the sediment has been flushed out and the water is running clear.
Is hydrant flushing a waste of water?
No, the amount and cost of
water used in flushing is a small price to pay compared to the benefits of
assuring the quality of your water and maintaining our infrastructure.
Do other Towns have similar water main cleaning programs?
Yes, many Towns have some
type of flushing program to clean their water mains (either conventional
flushing or unidirectional flushing). This is considered the best way to
improve water quality and increase the reliability of the water distribution
system.
