WATER & WASTEWATER
Water for rural communities Thembisile Hani Local Municipality’s new water treatment works (WTW) provides a new lease on life for communities living in nearby villages that include Boekenhouthoek, Mathysenloop, Machipe and Bundu.
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rior to this, the municipality mainly depended on other water services authorities for their bulk supply. This included about 15 Mℓ/day from City of Tshwane Metropolitan Municipality, 5 Mℓ/day from Dr JS Moroka Local Municipality, and 35 Mℓ/day from Rand Water. “Considering operational issues, such as pump failures, the supply was very inconsistent, leaving communities without water for extended periods, especially during the warm summer periods,” says Sarel Holtzhausen, executive director of Ceenex. “The situation has also been severely exacerbated by the drought, with water sometimes having to be transported by road tankers to severely affected areas.” Ceenex was appointed as the specialist subconsultant for the WTW and pump
This is Thembisile Hani Local Municipality’s largest infrastructure project and its first WTW
system design working alongside Monde Consulting Engineers, the lead engineer on this project. The water augmentation scheme is funded by the Municipal Infrastructure Grant and is being implemented in phases. The municipality is already supplying over half of the total demand of the planned supply zone at 3 Mℓ/day. The tender for the construction of the final units is expected to be awarded shortly.
and super vision of the various construction components of the scheme. These included the WTW and a new weir and abstraction point on the Moses River with a capacity of 5 Mℓ/day. The new infrastructure replaces an existing weir that was initially used for agricultural operations before it was damaged by floods. Ceenex also super vised the building of a new 10 Mℓ/day command reser voir and the construction of sections of the 8 km bulk pipeline associated with the scheme.
Resource study Initially, Ceenex was involved in the resource study for the availability of surface water sources within the area, the findings of which were incorporated into the scheme’s master plan. After the resource study, Ceenex was appointed by the municipality for the design
The project includes a new weir and abstraction point on the Moses River A sub-base section ready to be stabilised with PPC Sureroad cement
WTW process design The WTW incorporates a conventional treatment process to simplify operation and uses a high-pressure pumping system that comprises top-of-the-range variable-speed pumps sourced from a local manufacturer. In addition, a novel mechanical rapid gravity sand filter was selected for the removal of fine suspended solids. The polishing filter does not require an external control system or electrical supply, with the backwash cycle initiated autonomously and driven entirely by built-in hydraulics. This limits operator intervention to periodic maintenance inspections. Powdered activated carbon was also incorporated into the treatment process to remove colouring from the water extracted from the Moses River.
IMIESA May 2021
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