29 August 2012 - Aurecon’s Meulwater Water Treatment Works (WTW) project for the Drakenstein Municipality in Paarl, won the top accolade at the Consulting Engineers South Africa (CESA) Aon Engineering Excellence Awards in the category ‘Engineering Excellence with a value less than R50 million’.
The prestigious awards function was held on 15 August at Vodacom World, Midrand, “as a platform to showcase the important role that infrastructure plays in the sustainable development of our country” and was a “celebration of innovation, quality, outstanding workmanship and professionalism in the industry”.
The 8 Mℓ/d Meulwater WTW was commissioned in May 2012.
“The design team overcame significant challenges in providing a solution for the water needs of the Drakenstein Municipality in an extremely sensitive environmental area,” says Brendon Theunissen, Water and Wastewater Engineer and Project Leader for the Meulwater project.
The WTW treats water from the Nantes and Bethel Dams which are sited on the Paarl mountain, and is located on the boundary of the beautiful Paarl Mountain Nature Reserve.
“Due to its location, the plant was designed with careful attention to ensuring that it fits appropriately into this environment, while continuing the heritage of water supply and treatment on Paarl Mountain,” comments Theunissen.
The involvement of professionals such as a heritage specialist, botanist, landscaper and architect, added to the team of treatment specialists and engineers, has resulted in a special product that will hopefully prove to be a heritage for the community served by the Drakenstein Municipality.
Design features worth noting include the architectural style of the WTW to minimise its visual impact.
Theunissen explains that “extensive use was made of granite sourced from excavations for the WTW for cladding of all structures so that the building texture closely approximated that of its surroundings. The site was also re-vegetated with indigenous seeds and plants carefully collected from the mountain reserve under the supervision of the Parks Department.”
On the process side, he says that “direct filtration, which is unusual in South Africa, was chosen to minimise the plant footprint and provide an effective solution for the design water quality. The filters are designed to be easily upgradeable to dissolved air flotation-filtration units in the event of changes in raw water quality, should the client choose to make more extensive use of the existing supplementation scheme that allows water from the Berg River to be pumped into Nantes Dam.”
Additionally, the filters are equipped with a dual-parallel lateral under-drainage system, which is a novelty in South Africa. This system has been incorporated as part of an overall design to enhance the filter performance through the incorporation of optimised collapse-pulsing backwashing.
“The motivation for constructing the plant is partly due to the long-term saving afforded to the Municipality, when contrasted with the alternative of purchasing water from another water supply authority. Additionally, the supplement scheme using pumped water from the Berg River in Nantes Dam is only viable if there is a treatment facility for the water,” concludes Theunissen.