The media was taken on a guided tour by Joburg Water through the Driefontein Wastewater Treatment Works.
Joburg Water marketing and communications officer Eleanor Mavimbela, together with management walked the group through the treatment facility on 8 March. The tour explained how sewage is collected, treated and then dispersed. Driefontein collects a total of 55 mega litres (55 million litres) sewage from Randburg, northern Roodepoort and Mogale City. The facility recently upgraded their capacity by 25 mega litres at a cost of R295 million and will receive another upgrade for a further 25 mega litres.
Joburg Water said, “Wastewater treatment is a process of converting water that is no longer needed or suitable for use into an effluent (waste) that can be returned to the water cycle with minimal environmental issues.”
The process follows numerous complicated procedures to ensure comprehensive treatment of the waste. The facility is a completely automated 24-hour system and has around the clock manual checks as well as an online chemical monitor with backup generators servicing the entire works.
The process first starts at the head of works which collects the incoming sewage. From there the mass moves to the screening building where non-biodegradable items such as condoms, sanitary pads or sticks, are separated. The process then moves to the ‘degritting’ stage where sand is removed. From there the primary settlement tanks collects the raw sludge that settles at the bottom. The raw sludge travels to the fermenters and the overflow is kept in the balancing tanks.
The fermented solution is sent to the bio reactors to remove the phosphorus chemicals. Thereafter, the process moves to the disinfection tanks where a by-product of chlorine is used to ensure negative bacteria such as e-coli, has been removed.
Listen to Driefontein Waste Water Treatment Works manager explain the process further:
Mavimbela explained that the water is then sanitised and suitable for irrigation, which is currently being used in places such as Stein City and flows into the Crocodile River. Joburg Water is also working on a project to further distribute the water to be used by bulk users such as golf courses or the mining industry.
The tour lead the group to the new reservoir that will supply the Diepsloot community. The reservoir is still being built and will house 25 mega litres of water, with it being 55 metres in diameter and about 30 metres high. The expected date of completion is August. Willie Strydom, one of the head engineers on board, explained that the next reservoir will cost around R55 million.
Finally, Joburg Water brought the group to a water leak in Kya Sand. Here, Mavimbela elaborated along with the inspection team how long it takes to detect even one leak.
Overall the tour was extremely informative and provided a glimmer of hope. This is because one is able to appreciate the laborious process of sanitation, the massive infrastructure and the continued maintenance thereof. It created a sense of pride and gratitude for our City that is working efficiently.
Details: Joburg Water, firstname.lastname@example.org or 011 688 1400.