Physical Address: 1 Carnation Road, Welgedacht AH, Springs
The Welgedacht works is situated in the DD5 area with a design capacity of 35 megalitres per day. The process comprises the following stages : Three sets of Archimedean screw pumps lift the raw water into the inlet works in two stages. Two coarse screens followed by two automatic fine screens and screw compactor, are used to remove rags from the influent. Grit is removed in two automatic Pista degritters.
The reactor utilises a 5 stage Phoredox process configuration, with the following zones : anaerobic anoxic,aerobic, second anoxic followed by re-aeration. Aeration is by 16 surface mounted aerators and mixing by 13 submersible mixers. Effluent from the reactor flows into three parallel biological clarifiers from which the underflow is recycled back to the anaerobic zone of the reactor. Excess sludge is wasted from the underflow. The clarifiers overflow to three chemical clarifiers where ferric chloride or polymers can be used for additional phosphate removal. Chlorine is used to disinfect the water, and excess chlorine is removed by automated sulphonation.
Sludge handling includes the use of three linear gravity screens followed by three belt presses, after which the sludge is dried on sludge drying beds.
Capacity : 35.00 Mℓ/d