When it comes to treating wastewater, Nereda® is a technology with the means to achieve it more sustainably.  Furthermore, the current challenges faced by the South African wastewater treatment industry can only be overcome through innovative and sustainable treatment technologies, such as Nereda®, specially when South Africa produces 800 million litres of sewerage a day.


For most people, sewerage is best kept out of sight and out of mind. What we don’t realise is quite how much sewerage we produce on a city, provincial or even country-wide scale. South Africa produces 800 million litres of sewerage a day. Yes, a day.

As you can imagine, dealing with that quantity of sewerage is very costly. Not only does it have to be removed from your own home but it has to be sent across town, sometimes even across a province to the treatment facilities. At the plants it then has to be treated and cleaned up before it can be returned to our rivers and dams where we can use it, safely, once more.

Lowering your energy bill by treating water on the Nereda way

Operating the current wastewater treatment facilities costs South Africa approximately 5 billion South African Rand per year and it uses 3 million gigawatts of power. I must say, it puts one’s monthly energy bill into a little more perspective.

Now, imagine if we could halve that? At Royal Haskoning DHV we have developed our Nereda System of sustainable wastewater treatment. Instead of the current activated sludge system, Nereda uses aerobic granular sludge to clean the water. The bacteria which eats the pollutants in the sewerage grows in the aerobic granules making it denser, which means there can be a higher concentration of the bacteria, so the pollutants will be devoured quicker. It also settles a lot quicker in the settling tanks, which means one tank can be used for the entire process instead of a range of tanks.

There are three Nereda facilities in South Africa, in the municipalities of Gaansbai, Wemmershoek and Hartebeestfontein. They will be seeing an almost 50% reduction in energy costs and a 70% reduction in the treatment facility footprint size. 

It’s an expensive procedure to switch, but the results in the end, financially and energy-wise, far outweigh the initial cost. But, convincing other cash-strapped municipalities trying to fund other urgent needs to convert to Nereda is the real challenge. 

If you want to read more about Nereda, please visit nereda.net

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