Thembisile Hani Local Municipality – Bundu Water Treatment Works (WTW)


AGF: Autonomous Gravity Sand Filter

Client: Thembisile Hani Local Municipality – Bundu Water Treatment Works (WTW)
Industry: Municipal Potable Water
Region: Mpumalanga, South Africa
Product: 4 x AGF48SA – Autonomous Gravity Sand Filter – ±10 MLD
Installation: 2017


  • Thembisile Hani Local Municipality launched the Bundu Water Treatment Works (WTW) to provide clean, safe potable water to remote rural communities in Mpumalanga.
  • Many challenges had to be overcome including poor accessibility, low funding, little or no electricity on site , and a lack of operational bulk water filtration skills.
  • The Bundu WTW’s initial design included traditional large (20x20m) concrete water filters with traditional backwash systems, which are complex, expensive and time-consuming to build, and then also require ongoing human management, continuous power supply and high operational and maintenance costs.


  • Polishing filter for Bundu WTW for the removal of fine suspended solids from the water post clarification.


  • Following a specialist consultation with Superior Filtration (who have extensive experience polishing potable water for rural communities) – freely available to all design and construction engineers – the scope of work changed from concrete filters to mechanical Autonomous Gravity Sand Filters (AGF).
  • Factors taken under consideration:
    • Ease of Installation (reducing capital outlay and speeding up final plant delivery)
      • Minimum civil works on site.
      • Filters are transported to site and installed in place with limited mechanical assembly.
    • Complete Autonomous Function i.e. automatic
      backwash, no backwash pumps, no human
      inputs, no external controls.
    • Low Maintenance with virtually no downtime
      due to high reliability and efficiency.
    • Zero Energy Consumption.
    • Human Intervention Limited to periodic
      maintenance inspections.


  • Easy and rapid installation and commissioning.
  • The Superior Filtration AGF was installed in just two days.
  • The AGF was the first process unit to be installed on site at Bundu WTW, and was used through direct filtration a full year before other process units, such as sedimentation tanks, were
  • As a result, the municipality was able to supply the community with high quality water suitable for drinking much earlier than anticipated and long before the completion of the plant construction.
  • The Bundu WTW Sand Filters have been operating smoothly and entirely autonomously for five years already, without any electricity, human intervention, maintenance, or downtime.