UPGRADING AND REHABILITATION

The Vredefort Sewerage Treatment Plant entailed upgrading and rehabilitating the Vredefort Sewerage Treatment Plant. The plant uses an older treatment process of settling ponds with an aeration system incorporated into it.

The flow enters the plant at the inlet of works flowing through a coarse bar screen and a constant velocity grit channel. Grit and rags are removed at this stage. A transfer pump station with three submersible chopper pumps transfers the flow via a distribution chamber into two aeration tanks. Fine bubble diffusers are installed in the aeration tanks, which have four rotary lobe blowers (three duty, one standby), blowing air through the diffusers. After aeration, the flow enters two consecutive settling tanks lined by a 1mm HDPE liner, followed by five consecutive ponds. In the final pond, disinfection by chlorination occurs, where the final treated effluent flows into the river.

The two settling tanks and the first two ponds have submersible de-sludging pumps, which de-sludge into ten sludge drying beds or return activated sludge into the system at the distribution chamber.

The bucket system has not been eradicated in the area and as such provision for the disposal of the waste has been incorporated into the system by a Septic Holding Tank, which flows into the grit channel.

The plant is manually operated from the new MCC that was in- stalled in the electrical room.