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CONSTRUCTION WORLD
APRIL
2017
46
WASTE MANAGEMENT AND RECYCLING
Situated close to the Helios substation in
the Hantam Municipality, when completed
these two wind farms will boast a total of
122 wind turbine generators between them
and each will feed 563 500 MWh of clean
renewable energy into the national grid.
The Loeriesfontein Wind Farm and
the Khobab Wind Farm were constructed
by Murray & Roberts Construction in a
consortium with CONCO. Significantly,
the two companies also successfully
completed the construction of the Noupoort
Wind Farm for operator, Mainstream
Renewable Power South Africa.
An arid region
“Constructing such important projects in
this remote location called for innovative
thinking on our part,” Stephan Venter,
project manager for Murray & Roberts
Infrastructure, says. Boesmanland in the
Northern Cape is an arid region, which has
been further exacerbated by the grips of
a severe drought making the availability
of water a major challenge for all. As a
result of this major water scarcity, limited
extraction rates were allowed in the Water
Use Licences.
Venter says that the water shortage and
low extraction limit was taken into account
by the Murray & Roberts Infrastructure
team, and an intense water management
plan aimed at reducing water consumption
was put into place.
Marli van Rooy, environmental officer
for Murray & Roberts Infrastructure on the
project, says that the main strategy was
to reuse as much of the water under the
company’s control as possible as this
would reduce the need to source additional
water supply.
As part of the initiative, Murray &
Roberts Infrastructure installed a modular
water treatment plant on site. The plant
has a screening system which removes
the heaviest solids, while bacteriological
rollers treat the remainder. Significantly, no
chemicals are used during the process.
“Having the plant allowed the treatment
of grey and black water generated on site
and the reuse of this recycled water for
construction purposes,” Van Rooy explains.
Majority of the recycled water was
used on the earthwork layers for the wind
turbine bases. On average, the treatment
plant cleaned 30 000 litres per day and the
treated water was stored in two reservoirs
for reuse.
Another initiative aimed specifically
at reducing water consumption was the
construction of a specialised wash bay
solution at the on-site batch plant. “Wash-
ing the drums of readymix concrete trucks
is a necessity on any construction site, but
wasting water is not,” Van Rooy explains.
The wash bay comprises a series of
settlement ponds, with each having an
overflow which reports to the next pond
once it reaches a certain level. The concrete
sludge settles in the pond and once this
happens it is removed manually and left on
a specially constructed bunded slab to dry.
“This resultant dried material was removed
INNOVATIVE
environmental
INITIATIVES
An innovative approach saw
several impressive environmental
initiatives implemented by
Murray & Roberts Infrastructure
on the Loeriesfontein Wind Farm
and Khobab Wind Farm project in
the Northern Cape.
Marli van Rooy, environmental officer for Murray & Roberts Infrastructure, outside the modular water treatment plant installed by the company.
“On a site as remote as this, soil contamination
can be an extreme challenge as there are further
complications including the distances to the nearest
hazardous landfill site which is in Cape Town.”