Water & Wastewater Asia January/February 2021

FOCUS 31
learning curve has shortened…
Previously, you’d need a few months,
maybe even years, depending on the
person who is able to train them to
use tools for leak detection.
Smartphone sensors are used to monitor smaller water pipes
and detect leaks within two metres of the pipe
The trial was successful, with
the sensors detecting 13 leaks
over a three-year period. In one
incident, the sensors alerted PUB
to a potential leak on a 700mm
diameter water pipe alongside a
major expressway in 2018. Upon
excavation, a 13mm corrosion hole
was discovered at the bottom of the
pipe, within 0.5m of the location
reported by the sensors. This early
detection allowed PUB to promptly
repair the pipe and prevented further
water loss. Following up from the
trial, PUB plans to progressively
scale up the number of sensors
in the network and deploy 1,200
sensors islandwide for leak
monitoring by 2021.
PUB is also exploring use of inline
pipe inspection tools for leak
detection in large water mains. The
tool is inserted directly into the pipe,
which allows for more targeted and
precise inspection of the pipe wall,
to detect any cracks or anomalies.
Propelled by the flow of water in the
pipe, these tools can easily survey
long stretches of a pipe in a single
deployment. One such tool is a ballshaped
sensor that can pinpoint the
leak location to an accuracy of two
metres by picking up acoustic or
noise signature related to leaks.
PUB will be deploying these sensors
to survey 500km of pipes over the
next five years.
For smaller water pipes, the
PUB leak detection teams were
recently equipped with smartphone
sensors, a portable and easy-touse
survey tool that has proven
to be effective in locating leaks.
The sensor, connected to a
smartphone, is placed on pipe
fittings such as hydrants and valves
to pick up sounds from the pipe.
The smartphone automatically
digitalises and analyses the
acoustic signal in real-time via a
dedicated mobile application to
check for leaks. Two sensors can be
deployed on separate pipe fittings
at once to correlate and pinpoint
the leak location within two metres
along the pipe.
JUST KEEP LEARNING
This new technology has also made
it easier for younger engineers to
learn on the job. Waseem Khan,
senior engineer with the Water
Supply (Network) Department,
commented, “The training and
When you’re using the listening
stick, it’s actually very complicated
because there are other ambient
noises present – vehicular traffic,
people using water, environmental
noises that are present – and you
have to do all that processing and
filtering in your brain. That takes
years and years of training, but if
you’re using a smartphone sensor
like we are right now, all that filtering
and amplification is going on in the
phone. All the user has to do is listen
out for the leak noise.”
That isn’t to say that older engineers
like Ong Guan are left behind,
however – the 66-year-old extolled
the virtues of self-improvement
and shared how his keenness to
learn has brought him to places like
Brunei and Mauritius to provide leak
detection consultancy services.
“In the many years I’ve spent doing
leak detection management, I’ve
been able to apply my previous
experience… And with these
new skills, I’m able to train new
engineers,” he said.
Photos by Natalie Chew
With a willingness
to keep learning,
older engineers
like Ong Guan
are able to stay
on top of new
technology
used for leak
detection – and
train younger
engineers too!
January / February 2021 • waterwastewaterasia.com