“When BlueGreen Water Technologies first came to South Africa to clean lakes, we asked the local authorities to give us their worst. A lake with a toxic bloom like nothing else.”
In the fall of 2021, for the first time in decades, the people of Mahikeng, South Africa were able to receive safe drinking water from their main water supply source – Setumo Dam.
Setumo Dam is the beating heart of South Africa’s North West Province, but for years it had been severely contaminated by toxic algal blooms. The 3.5 square kilometer dam located on the Molopo River not only provides drinking water but also opportunities for fishing and recreation for half a million people of Mahikeng, North West's provincial capital.
The cause for Setumo Dam’s algal problems was a water treatment facility that resides on the Northwest section of the Dam and discharges insufficiently treated sewage into the water. The nutrients led to severe cyanobacteria blooms that prompted locals to complain about the noxious odor and taste of their drinking water.. The Dam’s high cyanobacterial cell content far surpassed the levels deemed safe and approved by the World Health Organization and the South African Bureau of Standards and prompted officials to class the waterbody as “untreatable”.
Many regions in South Africa suffer from toxic algal blooms for different reasons, yet the outbreak at Setumo Dam was considered one of the worst cases in the country.
“We undertook this project pro-bono, knowing it was the only chance for this community to access clean drinking water, enjoy Setumo Dam as a safe water source, and unleash its potential for recreational purposes.”
In March 2021, the BlueGreen team was invited to treat Setumo Dam in collaboration with Sedibeng Water, the Department of Water and Sanitation, and Rand Water Analytical Services. “When BlueGreen Water Technologies first came to South Africa to clean lakes, we asked the local authorities to give us their worst. A lake with a toxic bloom like nothing else.” We figured, if we are going to do a major pro-bono project, let's make it count,” said Eyal Harel, CEO, BlueGreen Water Technologies.
“We undertook this project pro-bono, knowing it was the only chance for this community to access clean drinking water, 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 livelihood of their communities,” said Harel.
“Shortly before starting treatment, we witnessed the local community performing rituals that involved entering Setumo Dam’s toxic water. We saw some fishermen trying to catch the few small fish that survived the harsh conditions. We grasped how underdeveloped the area was, in spite of its amazing potential. And we realized that once cleaned, we wouldn’t just improve the health and livelihood of the people around Setumo Dam, we would create a historical opportunity for local authorities to turn the lake into a place that could bring about much-needed development and prosperity.”
A special treatment protocol was tailored for the unique, extreme conditions in Setumo Dam to reduce the massive toxic algae in the water while eliminating the disturbing taste and odor compounds from the drinking water. Lake Guard®️ Oxy technology was selected for the treatment due to its unique characteristics – it’s designed to eliminate cyanobacterial toxic blooms by triggering the cyanobacteria to “commit suicide”, leaving no trace in the water. When the products are applied to the infected waterbody, the harmful algal bloom dissipates in hours, without harming the aquatic ecosystem’s plants or animals. More beneficial species can then begin to grow in the ecological vacuum created by the blue-green algae suicides.
Lake Guard® Oxy treatments were applied all over the lake by a helicopter in June 2021, and by August 2021, the change in the dam water was drastic, as shown in the picture below.
Picture of Setumo Dam on June 8th before treatment (left) and on Aug. 19th, 72 days after the treatment campaign with Lake Guard® Oxy (right).
BlueGreen’s treatment was successful and restored the water to drinking standards for around 500,000 residents and in the process, removed tens of thousands of tons of carbon. Many locals shared personal stories of the treatment’s direct impacts on their lives. “It was a disaster. When you came here, you would find dead fish to start with – a lot of dead fish. It would smell rotten. You couldn’t even come and chill here, because it was not clean,” said a young local. “Right now, it’s something else. You can take a look at the water,” he said with a big smile on his face, pointing to the clear lake surface behind him.”
“To enter this water with that chemical – you see my skin here, it used to change – you have to put Vaseline first before you get inside the water,” shared another resident. “But now you can see the water is clean and it’s fine. That chemical has disappeared. And now we can fish, and the smell of that chemical is not there. The water is clean and we are happy,” he smiled.
Eliminating the toxic algae in the water not only facilitates safe drinking water for the community but also creates the opportunity for Mahikeng to unleash the Dam’s full potential for recreational and religious purposes. With Setumo Dam free of harmful cyanobacteria, local authorities were planning to utilize the Dam’s potential as a recreational attraction.
We hoped that the improvement in the water quality would open a chapter of livelihood and prosperity for the region. Unfortunately, many months later, we learned that the water quality in Setumo Dam began to deteriorate again due to the government’s lack of funding to keep it clean. We wish to return to Mahikeng and once again remediate Setumo Dam and bring safe drinking water and the pleasant view back to the local community.
As BlueGreen is about to introduce Net Blue carbon credits associated with the sedimentation of fantastic quantities of carbon in the process of toxic blooms' remediation, the rehabilitation of Setumo Dam will not only benefit locals but also the entire world in its fight against climate change.