Facts & Figures
|Location||Stellenbosch, South Africa|
|Process Configuration||Pre-treatment + Nereda + Chlorination + Maturation pond|
|Nereda Design Capacity:|
|• Dry Weather Flow||5 MLD|
|• Peak Flow||600 m3/h|
|• PE||36,250 PE (PE = 60 gBOD/d)|
|In the Media:||Engineering News|
About the Wemmershoek Nereda WWTW
Wemmershoek is a small village in Cape Winelands District Municipality, in the Western Cape province of South Africa.
Wemmershoek WWTP is located in the Western Cape province of South Africa. As part of the provincial government’s Berg River Improvement Plan (BRIP), which was developed in 2012, Wemmershoek WWTP was scheduled to handle increased flow. This was due to the Franschhoek plant – which offered limited extension opportunities – being decommissioned as part of the process. The increase in excess effluent that needed to be treated would require greater efficiency and capacity from Wemmershoek and a new and innovative solution was called for.
Image: Overview of the Wemmershoek WWTP
The SolutionStellenbosch Municipality, the project’s instigator, had already decided not to upgrade the Franschhoek plant, as it lay within the stringently controlled Berg River catchment area. This left Wemmershoek as the sole provider of effluent treatment in the Berg River basin. Royal HaskoningDHV proposed that its Nereda wastewater treatment technology would be the ideal solution to the challenges faced by the required upgrade.
Completed at a cost of R65 000,000.00, the new 5 ml/d system was commissioned in 2014, with plant start up following in 2015. The design is tailored to Wemmershoek’s specific environmental conditions and requirements. Primary treatment consists of screening and grit removal. Secondary treatment incorporates a 600m³ Nereda Influent buffer and two 1800m³ Nereda reactors. Average dry weather flow is 5 ml/d, rising to 14.4 ml/d for peak wet weather flow. Tertiary treatment is via chlorine disinfection and maturation pond, and the sludge treatment method is mechanical thickening and dewatering. Effluent is discharged into Berg River and reused for irrigation purposes, pumped to Franschhoek. This ensured that the need for extensive tertiary treatment – to meet even more stringent future standards – was not required. As a result of the upgrade, Stellenbosch Municipality’s project was nominated for a CESA Engineering Excellence Award, for its innovative and cost-efficient wastewater treatment works at Wemmershoek.
The local benefits of the project
|Enhanced water treatment|
|Meets industry standards|
|Cost efficient process|
|Functions is dry climate|