Water, Sewage & Effluent March April 2019 | Page 15

When pumps shut down, a water surge occurs — where
water continues along the pipeline for a certain distance,
but then backwashes and causes a surge.
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Each welder joint has a coating on the outside of the pipe for corrosion prevention and
sealing.
A project of this scope and magnitude
is not without its challenges. Barnard
says, “Typically on site, you will find
some M&D plant, and some plant from
local suppliers. Although we have all
the plant available in-house, first option
is to use a portion of local plant. If the
locals do not have the kit we’re looking
for, then we’ll use our plant available.”
Steyn says, “Whenever we need
plant equipment, we speak to the
project steering committee (PSC) —
made up of councillors appointed by
the council, and the local community
liaison officer (CLO) — made up of
community spokespeople. What makes
this project interesting is that it starts
in Tshwane and crosses into Moretele
in the north-west — which means that
not one, but two local communities are
involved. Each community has their own
appointed CLO. Each CLO represents
the individual community’s needs and
requirements and therefore each
needs to give approval in all matters
individually. This means whenever we
hire labour, plant equipment, or any
other items, it has to go through the
individual CLOs, the PSC, and then
out to the community. Then only does
it come back to us, once all parties
have agreed and approved the way
forward,” says Steyn.
Barnard says, “Aside from this
being a time-consuming exercise —
having to get permission every step
of the way through the CLOs, the
PSC, and the locals — it can also
get quite complicated in that there
is not one external supplier who will
supply five different plant units, but
five different suppliers each supplying
Challenges
time, but we keep record of it,” adds
Barnard.
Despite the challenges, M&D is on
track to complete the project by mid-
2020, which will increase capacity to
ensure the delivery of services across
the water value-chain and support the
‘source-to-tap’ vision. Working closely
with the municipalities, M&D will bring
efficient water service delivery to
the end consumer, communities, and
industries served by Magalies Water. 
one piece of equipment. The logistics
itself is time-consuming, but it’s also
understandably not very economical
since you end up paying five suppliers,
and not just one.
“Stoppages do hamper production,
but we have found that the best and
quickest course of action is to involve
the CLOs immediately and the local
municipalities, who assist in solving the
problem. A stoppage can be anything
from between two to three hours at a
Each pipe has a block with the chainage (linear pipe length), the joint number, the welder
number, and the date the pipe was welded. Every joint is recorded.
Water Sewage & Effluent March/April 2019
13
to drain the pipeline so you can work
on the affected section. In addition to
this there are isolation points, which
require chambers to be built — which
is civils work,” he says.
Steyn says that pressure is at nine
bar for the 700mm pipes, and this
pipeline project will include surge
tanks in case of a shutdown on the
pumps. “When pumps shut down, a
water surge occurs — where water
continues along the pipeline for a
certain distance, but then backwashes
and causes a surge. The pressure
when this occurs is so high that it
can remove the water lining and
even cause the pipe to break in some
instances. For this reason, there will
be surge protection, where the water
comes up into a surge tank, returns
at a slower rate, thereby reducing the
flow pressure,” explains Steyn.