Water, Sewage & Effluent September October 2018 | Page 19

The project was under way at the
time of writing and work had started
with the tie-ins, Kleynhans explains.
“We first had to lay the pipelines in
parallel and then we connect the new
one right at the pump station, with
both the old and the new pipelines
‘live’. Thereafter, every upstream
connection is tied in from the old pipe
to the new pipe. Once the connections
are completed, the old 3 800m, DN 800
asbestos cement sewer pipeline is
decommissioned entirely.”
The old pipe then remains in the
ground, Kleynhans explains. “Where
we have the pipe going underneath
existing roads, because we are
concerned about traffic load, those
sections are grouted up to ensure that
the pipe doesn’t collapse structurally
over time. The section that is in an
open field is about one-metre deep
and does not have any traffic load;
therefore, grouting is not necessary.
We do, however, seal up the manholes
to mitigate the risk of people falling
into the holes where covers have been
vandalised or removed.”
In a contract comprising so many
elements, challenges are inevitable.
John Reed, contracts manager for
Construction of MH38 on the DN 1200 diameter pipeline along Macassar Road.
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