Joburg’s dirty problem: Underperforming wastewater plants

The city is releasing partially treated water back into rivers – and this has health and environmental implications

By Gemma Ritchie
Monday, July 10, 2023

Driefontein was the only wastewater treatment plant in Johannesburg that achieved 100% microbiological and chemical compliance.
(Photo: Green Development Foundation/Twitter)

  • Only one of Joburg’s six wastewater treatment plants passed minimum microbiological safety standards in the latest Green Drop report
  • The wastewater plants with the worst microbiological compliance are in the south of Joburg and feed into the Klip River, which feeds into the Vaal
  • If water isn’t treated properly, it can introduce bacteria such as E. coli into river systems as well as chemicals that starve fish and plants of oxygen

On a Sunday morning walk through a park in Joburg, one can often see church members being baptised.

Unfortunately the river water isn’t holy. 

It’s filthy. 

And it concerns water scientist Ayesha Laher, because it is not just chip packets fouling the water. 

‘Our rivers are not clean,’ says Laher, whose company AHL Water focuses on the sustainable management of water and wastewater systems. ‘People are baptising in rivers and they don’t know what the health implications are. They could be mild, long term or potentially dangerous.’

State of Joburg’s treatment plants

Johannesburg has six treatment plants that clean the used water from our kitchens, bathrooms and businesses before releasing it into five rivers: Crocodile River, Harrington Spruit, Jukskei River, Klip River and Rietspruit.

The Department of Water and Sanitation’s latest Green Drop report grades South Africa’s treatment plants on their management, the state of their infrastructure as well as the quality of water released into rivers. All of these factors inform a plant’s Green Drop score. 

One component of this score is the level of microbiological and chemical compliance of the treated water. The regulated standard for microbiological and chemical compliance, set by the Department of Water and Sanitation, is 90% and higher. 

The water should only leave the plants once bacteria and minerals have been removed, making it microbiologically and chemically compliant.

If this is not done, the poorly treated water introduces chemicals that starve fish and plants of oxygen and introduce bacteria such as E. coli into river systems. Drinking water with E. coli can make animals and humans ill.

When a treatment plant cleans water, it removes human waste as well as chemicals such as carbon (from faeces), nitrogen (from urine) and phosphorus (from soaps). Chlorine is added to kill bacteria. These cleaning processes, which happen in multiple steps, make the water microbiologically and chemically compliant.

  • Driefontein was the only wastewater treatment plant in Johannesburg that achieved 100% microbiological and chemical compliance
  • Two stations performed horribly: Olifantsvlei scored 4% for microbiological compliance and Goudkoppies scored 5%. Olifantsvlei discharges into Klip River, which feeds into the Vaal. Goudkoppies discharges into Harrington Spruit, which feeds into Klip River
  • Bushkoppies, Ennerdale and Northern Works all failed to achieve a score of 90% or above for microbiological compliance

Why is this happening?

The Green Drop report says the reasons for the poor performance of the treatment plants include

  • A lack of maintenance
  • Ineffective cleaning processes
  • Electrical cable theft

And it’s not a small problem. Although Olifantsvlei and Goudkoppies are the most problematic wastewater plants, the Green Drop Report calls out five of the six: ‘The lack of microbiological compliance at all plants except for Driefontein presents a serious health risk to downstream users.’

It doesn’t help that Joburg’s wastewater treatment plants are processing more waste than they can handle.

Treating wastewater is a biological process, says Laher. ‘It depends on microorganisms that break down the sewage. If you overload the treatment plant, there will be too many solids [such as faeces] coming in and the microorganisms will die and it won’t work optimally.’

A lot of untreated used water also enters river streams when treatment plants lose power either because of loadshedding or cable theft. If the untreated water ends up in rivers or lakes, too much of it can turn the water septic, killing off plants and animals.

How is it being fixed?

The Green Drop Report’s suggestions to address Joburg’s wastewater problems include

  • Upskilling technicians 
  • Repairing infrastructure
  • Monitoring water disinfection

Johannesburg Water says it plans to replace critical and old infrastructure. In its latest annual report, the utility says it aims to improve its water treatment to 90%.

Joburg’s member of the mayoral committee for finance Dada Morero announced in June that Joburg Water would receive R3.1-billion to repair and upgrade treatment plants and replace water and sewage pipe systems, among other things. 

Joburg Water told The Outlier it is working to address the issues raised by the Green Drop report and the compliance of Goudkoppies and Olivantsvlei. 

‘The quality of effluent discharged at these water resources [Harrington Spruit, Rietspruit, Klip and Jukskei rivers] is tested frequently and challenges relating to non-compliance, or any related matter, are being addressed on an ongoing basis,’ it says.

Baptising in rivers

Can you still get baptised in rivers? Joburg Water didn’t say no. But it also says it ‘cannot take responsibility for the activities undertaken by community members due to various activities such as personal, cultural, religious or social acts’.

Laher says people don’t take the issue seriously enough. She has a personal crusade to stop people from using dirty river water: ‘Wherever I go, I ask people to please not do baptisms in the river. It really is a very high risk to baptise.’

Steps you can take

If you are living, hiking or walking near river water in and around Joburg, don’t drink it without first cleaning it. Below are tips on how to clean water

If you wash your hands, household items or clothes in a river, please use Joburg’s much cleaner tap water to rewash your hands and cutlery. 

If you don’t have access to tap water. You can

  • Boil your water. This is the best option as it kills pathogens
  • Add one teaspoon of bleach to 2l of water and let it stand for half an hour before drinking. This is a very cost-effective option
  • Filter your water using a clean cloth, coffee filter or paper towel. While cost-effective, this only removes sediment and does not kill bacteria

You can hold the city accountable for polluted water flowing into a river near you by contacting