Successful rehabilitation of Setumo Dam

Setumo Dam before and after treatment

BEFORE AFTER

Successful rehabilitation of Setumo Dam

For the first time in decades, the people of Mahikeng in the North West province are receiving safe drinking water from their main water supply source, thanks to a special treatment protocol from BlueGreen Water Technologies.

Setumo Dam had been severely contaminated by toxic algal blooms. Known as cyanobacteria or blue-green algae, these organisms use sunlight to make their own food. In warm, nutrientrich (high in phosphorus and nitrogen) environments, cyanobacteria can multiply quickly, creating blooms that spread across the water’s surface. They can either stay submerged or float to the water’s surface. Cyanobacteria blooms can look like foam, scum or mats.

Cyanobacteria blooms may affect people, animals or the environment by: • blocking the sunlight that other organisms need to live • stealing the oxygen and nutrients other organisms need to live • making cyanotoxins, which are among the most powerful known natural poisons and can make people and animals sick. The outbreak at Setumo Dam was considered one of the worst cases in South Africa. The heavy cyanobacterial load was the result of decades of insufficiently treated sewage being released directly into the dam. The dam’s size and level of contamination had deemed it untreatable.

“The heavy organic load was also disrupting the ability of the local water treatment plant to operate, increasing the overall costs substantially and keeping the final water quality well below national and international standards,” explains Jurgens van Loggerenberg, director: Africa for BlueGreen Water Technologies.

Treatment and outcomes BlueGreen introduced its Lake Guard solution to Setumo Dam, in collaboration with Sedibeng Water. The special treatment protocol implemented was tailored for the unique conditions in Setumo Dam by BlueGreen’s field specialists and its application was concluded with outstanding results.

“The project has positively impacted more than half a million lives as a direct result of improved water quality. Setumo Dam’s high cyanobacterial cell content (billions of cells per millilitre) far surpassed the levels deemed safe and approved by the World Health Organization and SANS 241,” adds Van Loggerenberg.

“BlueGreen is committed to making water safe,” explains Eyal Harel, CEO and co-founder of the company. “We undertook this project pro bono, knowing it was the only chance for this community to access clean drinking water and enjoy Setumo Dam as a safe water source, and unleash its potential for recreational purposes. We wish to empower local authorities to reclaim their water sources and advance the health and livelihoods of their communities.”

The successful treatment at Setumo Dam also eliminated unpleasant taste and odour compounds from the drinking water and opened up recreation opportunities in and around the lake that had been, up until now, impossible.

This project is the result of a joint effort that included the Department of Water and Sanitation, Sedibeng Water and Rand Water Analytical Services.

The success at Setumo Dam comes directly on the heels of BlueGreen winning the ‘Breakthrough Technology Company of the Year’ award at the 2021 Global Water Awards.

BlueGreen Water Technologies has been recognised for its “innovative solutions to the global epidemic of toxic cyanobacteria, undertaking major projects for cleaning extensive water bodies in the USA, South Africa, China and Israel”.

Colony of bluegreen algae in a culture medium plate