Physical Address: cnr Kalk / Van Dyk Roads, Rondebult

Rondebult is situated in Germiston and falls within the DD6 drainage district. It was built in 1937 and currently has a capacity of 36 megalitres per day. The works receives raw sewage from Germiston and Boksburg. Rondebult consists of two modules, implementing both biological filters and an activated sludge process to treat a combination of domestic and industrial sewage. The carbonaceous loading from the industries is particularly high and an activated sludge process was retrofitted to relieve the carbonaceous load on the biological filters treatment.

A central inlet works, incorporating screening and grit removal serves the plant. The biological filtration process includes primary sedimentation, primary biological filtration for carbonaceous removal, and secondary biological filtration for nitrification and humus clarification. The biological filters are all covered and fitted with blowers to provide for forced aeration. The combined effluent from the activated sludge reactor and biological filtration process is treated chemically to remove ortho-phosphorous and chlorinated before it flows through a series of maturation ponds.

Over the years a dense stand of reeds developed in these ponds, which attracted numerous numbers of species of waterfowl. This led to the establishment of the internationally known Rondebult Bird Sanctuary. Effluent from these ponds is discharged to a tributary of the Natalspruit, which eventually flows into the Klip River. Solid waste produced in the various processes on the works is stabilised in anaerobic digesters, from where it is disposed of on 70ha of land. The land is used to cultivate fodder.

Capacity : 36.00 Mℓ/d