Gauteng’s most problematic sewage treatment plant has released millions of litres of untreated sewage into the Jukskei River.
The problem is not isolated. The plant – Northern Works, outside Johannesburg – has been releasing untreated sewage for a decade. It is just one of hundreds of plants nationwide with the same problem.
Two issues led to the latest spill, according to the national water and sanitation department. One of the massive pipes carrying raw sewage into the plant got blocked by rubbish. The pressure forced sewage out of manhole covers and into the Jukskei. The second issue came about as a result of the upgrades happening at the plant. Here, the main sewage pond overfilled with sewage, which then flowed into the neighbouring river.
The reserve pond is being upgraded after years of neglect. Since late 2015, the pond has been desilted and lined to prevent polluted water leaking into the soil.
Johannesburg Water said the nearly R300-million upgrade will allow the plant to start operating at its full capacity. That will allow it to treat the 460 megalitres of wastewater it gets every day from Alexandra, Sandton, Randburg, Bedfordview and the rapidly expanding suburbs of northern Johannesburg. An Olympic-sized swimming pool is 2.5 megalitres.
The Greater Kyalami Conservancy – a nongovernmental group working in the area – said this happens at least once a month. The water and sanitation department said big sewage spills have been happening since upgrade work started late last year. But groups such as the conservancy say the plant has been releasing untreated water for at least a decade.
That sewage flows into the Jukskei, and then into the Crocodile River. That in turn flows into Hartbeespoort Dam, the major source of drinking and irrigation water for the eastern part of the North West province. The latest spill – late last week – flowed through this system over the weekend. Locals said the sewage was so thick that it turned the river into a dark shade of grey, and in parts black. Residents of Hartbeespoort went as far as to erect signs warning of biological waste.
The dam has been struggling with eutrophication – a response to an oversupply of nutrients that causes explosive plant and algae growth, in turn depleting oxygen and killing aquatic life – for decades.
The Crocodile River, its main source of water, is joined by the Jukskei and Hennops rivers. These drain everything north of central Johannesburg and carry heavy levels of polluted water from people and mining. The resulting nutrients feed algae in the dam and drive the eutrophication of its water.
Some R900-million was spent in the decade from 2004 to rehabilitate the dam. But the national water department has said in Parliamentary briefings that the high level of pollution flowing into the dam means the work is merely patching, not solving, the problem.
John Wesson, North West provincial manager for the Wildlife and Environment Society of South Africa, said the effect of the latest leak on the river and dam would be to “destroy the entire food chain in the area” and make the ecosystem “virtually sterile”.
This would only change if heavy rains in the area fell and flushed out the sewage, he said. But the situation will inevitably be repeated as work continues on Northern Works.
In a response to civil society questions about the plant late last year, Johannesburg Water said: “Sewage spills are due to frequent operational failures as a result of aging infrastructure, continuous power failures due to vandalism and theft of cables and limited emergency storage capacity in emergency retention dams due to silting up over the years.”
Dreams of clean water are washed away
By the government’s own admission, South Africa’s wastewater treatment plants are struggling to keep up with the growing demand. Municipalities run 821 plants, which have few engineers and little budget to upgrade and maintain them. The national government can only intervene when things break down.
As a way of nudging municipalities to fix the problem, the water and sanitation department releases its annual Green Drop report that assesses treatment plants.
The last report found that 40% of plants were in a critical state and that the more remote the municipality, the worse the problem is. In rural areas it’s almost certain that a town’s water treatment plant will release polluted water into rivers. This is why the European Union handed citrus growers in Limpopo and farmers in Mpumalanga export warnings – polluted irrigation water was cited as the reason.
Big metros fare better but rapid population growth and neglected maintenance mean that even these plants do not always release clean water into rivers.