- Category: PROJECTS
- Published on 30 May 2016
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By Kelly-Ann Prinsloo
Deep in the heart of South Africa lies Kimberley, a city that, was known for the Big Hole and not much else. Now, it is home to South Africa’s newest bastion of higher learning, Sol Plaatje University.
Named after one of the founders of the South African Native National Congress (SANNC), which we know today as the African National Congress (ANC), Sol Plaatje University is the first major university in the Northern Cape and brings with the hope of a solid tertiary education to millions of young South Africans who would otherwise have to travel to other provinces, far from their homes.
Sol Plaatje University is the brainchild of the Department of Higher Education and Training (DHET), and is an ongoing development that began in July 2014. The initial construction phase consisted of three main buildings, were handed over in the beginning of April, with the intention of erecting several more residence and lecture buildings over the next few years.
According to Aurecon, which handled the civil engineering on the Sol Plaatje project, the design specifications were not strictly outlined for wet services. However, it was made clear that a cost-effective solution was expected, with an emphasis on sustainability and best industry practice.
A centralised services building supplies the residence and academic buildings on the campus. This services building houses the potable water pump set, the grey water treatment system, hot water generation plant and pump set, and chillers for the TABS system.
Sustainability over all
Not only is the Northern Cape currently suffering from the same devastating drought as the rest of South Africa, it is also home to the driest place in South Africa, namely Alexander Bay, which receives an average annual rainfall of only 46mm. This mostly-arid province receives an average of 202mm of rain annually. And so, included in the design of the university are two 125 000ℓ potable water, galvanised sectional steel storage tanks.
These tanks, which are adjacent to the services building precinct, are fed by the municipal potable water supply before being reticulated around the campus via a 150 DN ring main. The potable water pump set comprises of five 6.4ℓ per second duty pumps with built-in standby capacity. The plant has a maximum delivery capacity of 38.86ℓ per second.
One of the stipulations on this project was sustainability. And recycling water is one of the most important sustainable living practices today.
At Sol Plaatje, black water is collected in a sump outside the services building and pumped into the municipal sewer line by three submersible macerating pumps. The sump overflow is also directed into the municipal line on Scanlan street.
“The different types of water and sewer lines made the project interesting and challenging at the same time.”
Grey water is collected from the showers and basins in the residence buildings and stored in a grey water sump adjacent to the blackwater sump outside the services building. The grey water is then lifted to the grey water treatment plant inside the building. The water is passed through a lamella clarifier, a sand filter and a UV steriliser before being pumped into the 101 500ℓ sectional steel non-potable water storage tank situated on the services precinct. The treated non-potable water is reticulated to all the buildings on the campus for flushing of toilets and urinals. The non-potable water tank has a municipal connection if more water is required.
The grey water system was implemented to mitigate the high water demand of the development. Low-flow shower heads and cisterns were also installed throughout the buildings.
Hot water is generated by four heat pumps and circulated through 4 x 7 500ℓ thermocube heat exchanger tanks. Cold water from the domestic water supply is fed through the thermocubes and circulated to the residence buildings via a ring main. Unused hot water is returned to the thermocubes and recirculated. The hot water supply pump set consists of 4 x 2.96ℓ, or second duty pumps. The circulation pump set consists of 2 x 1.5ℓ, or second duty pumps and one standby pump.
Each of the buildings on the Sol Plaatje campus has rainwater disposal systems that use a combination of gravity and siphonic drainage discharge systems. Even though a combination of two disposal systems is used, the two systems reticulate and operate independently. The rainwater is conveyed down the plumbing service shafts or ducts throughout the building via discharge downpipe and is connected into a common collector pipe that exits the building and flows into the site’s storm water drainage.
As you can image, given Kimberley’s history as a diamond mining town, the land upon which Sol Plaatje stands presented some problems. The building site had very shallow levels of hard rock, which made excavation for both structure and services extremely difficult. This was especially challenging when designing and installing the grey water recovery system, which had to fall over long pipe runs. Effort was made to shorten the underground pipe runs by reticulating in the upper floors as far as possible. However, some challenging rock excavation was required to achieve the appropriate falls to the grey water sump.
Valsir Uneeq products were used for all plumbing and drainage pipework. Valsir’s Rainplus system was used for the siphonic rainwater drainage, its HDPE pipes were used for drainage, and PPR was used for plumbing reticulation. The selection was based on a cost-weighted tender adjudication process.
Daniel van der Spuy from Vic Ball Plumbers, the main plumbing contractor at Sol Plaatje, says of Valsir’s Rainplus, “This is an impeccable system to use for multi-storey buildings. It uses much smaller diameter pipes as it works with the building’s height to create a negative pressure suction. These Rainplus 56 lines can move up to 840ℓ per minute through a 56mm HDPE pipe.”
Valsir’s concealed cisterns were also used, along with pneumatic push buttons, especially in the disabled bathrooms on the campus. In many disabled bathrooms, flushing the toilet can be difficult for the end-user because of where the flush button or lever is situated. Valsir’s pneumatic push buttons, both dual and single flush, are available both for wall and floor applications and can be located up to 2.5m from the flush cistern. What this means is that the flush can be placed alongside the toilet, within easy reach of the end-user.
Plumbing new depths
Vic Ball Plumbers joined the Sol Plaatje project in late November 2014, to work on the underground sewer lines. Kimberly is known for its hard rock and so, Daniel van der Spuy of Vic Ball Plumbers says, “It was quite a challenge to install the sewer lines at depths of up to 2.7m.”
The sewer system consists of a two-pipe system – one black water line connects all the toilets, sinks, and urinals, and a grey water line connects the basins and showers. The black water discharges straight into the municipality connection, which the grey water is pumped through a state-of-the-art purification plant that stores the water in a 108m3 sectional tank. The filtered grey water is then used to supply the toilets and urinals. Van der Spuy says, “The different types of water and sewer lines made the project interesting and challenging at the same time.”
He adds that because Sol Plaatje University was a fast-track project, the sub-contractors really had to be on top of their game at all times.
The booster, fire sets, and sump pumps were supplied by WILO SA. The six-pump pressure booster set was the first of its kind from WILO in South Africa. Previously, it had only been used in Europe.