Image for ‘Wastewater can be very valuable’: the hydroponic system that provides clean water for Kenyans

‘Wastewater can be very valuable’: the hydroponic system that provides clean water for Kenyans

Using the power of plants, Nairobi-based startup Omiflo has engineered an effective wastewater cleaning system. And it’s attractive to boot

Using the power of plants, Nairobi-based startup Omiflo has engineered an effective wastewater cleaning system. And it’s attractive to boot

At the Giraffe Centre in Nairobi, visitors can feed by hand pellets made from molasses to Africa’s tallest giants. It’s one of the area’s most popular tourist attractions and has played a pivotal role in conserving the critically endangered Rothschild giraffe. It’s fitting then that the centre is also home to another conservation project, one that’s preserving an increasingly scarce natural resource: water. 

“[The Giraffe Centre] wanted something that was green and that fit its philosophy. It’s a really beautiful project and is saving them a lot of money too,” says Mshila Sio, who founded Kenyan startup Omiflo. The company has installed a plant-based hydroponic system at the site that filters wastewater, which can then be used for landscaping, flushing toilets and more. This year, Omiflo was named one of 16 winners of the No Waste Challenge, a competition run through international design organisation What Design Can Do

Sanitation and access to clean water are critical challenges in Kenya. According to Unicef, only 29 per cent of Kenyans have access to basic sanitation, a figure that has fallen by 5 per cent since 2000. With the urban population expected to more than triple by 2050, from 12 million to 40 million, there are huge implications for water use and wastewater management across Kenya’s cities. Today, only 40 per cent of Nairobi is connected to a sewage system. 

Design-driven innovations to change the world The No Waste Challenge is a global design competition that addresses the impact of waste and consumerism on the planet Check out the 16 winners

“Wastewater treatment is usually an afterthought,” Sio says about why he started the company. “The conventional technologies just don’t make sense for a developing country. They cost too much, are too complex, and are too energy intensive. They’re not fit for purpose.” 

In contrast, the Omiflo system doesn’t require any electricity, chemicals or significant gardening experience to build or maintain. Typha (also known as Cattail) plants float on the top of a pond and absorb oxygen from the air. Then, the plants inject it into the wastewater through their roots, restoring health to bodies of water while creating beautiful natural spaces. The self-sustaining system has been designed to be scalable, working for settings as diverse as private homes and eco-lodges, to larger developments and municipalities. 

Mshila Sio, founder of Omiflo

Mshila Sio, founder of Omiflo. Image: Khalid Amakran. Courtesy of What Design Can Do

“Plants have been used to treat water for thousands of years,” says Sio. “The advantage of a floating system is that we use a much smaller space and eliminate the smell, the sludge – all of that ugly stuff. The installation cost is quite low and then operationally, you’re just looking after the plants. So, it’s very viable for low-income areas as well as high-income areas.” The water from an Omiflo system can also be drunk if a small chlorine dose is built in.

The idea for the company came while Sio was on holiday in Spain. He came across a startup called Hydrolution that had developed a wastewater treatment system using plant-based technology. Sio then spent years hassling the founders to bring the solution to Nairobi. They lost touch around 2013 when Spain’s financial crash put Hydrolution out of business. So Sio decided to do it himself. Omiflo’s first project rolled out in 2018 and the team has since installed 200 systems worldwide. 

“It took a few years to develop the technology and build a pilot to show how this works,” he says, adding that proof was necessary to secure investment. “We don’t have a culture of angel investors willing to try something new. Kenyans are very sceptical. They want to see and touch and feel. So, we had a big issue of credibility at the start. We had to do quite a few projects before people said: ‘OK these guys know what they’re doing’.” 


The advantage of a floating system is that we use a much smaller space and eliminate the smell, the sludge – all of that ugly stuff

In the end, investment came from a myriad of places. Sio was one of the winners of a grant through President Obama’s Young African Leaders Initiative in 2014 and received additional funding through a Dutch ministry of foreign affairs scheme, as well as through friends and family. Beyond the first pilots, that money also enabled Omiflo to build its own ‘biocentre’ in Nairobi. The intention was to have somewhere to grow the plants, showcase how the system works and carry out further research, but it’s become much more than that. 

“It’s a really cool place,” Sio enthuses. “People come and take a walk, they picnic there. We’ve transformed the ecosystem completely, just by recycling water. We find birds come in the morning, frogs … the whole area has been revived.” He readily admits that some residents living nearby were suspicious at first. “We went to all of our neighbours and said: ‘Can we have your sewage? Worst case scenario, we’ll plug you back into your septic tank and it’ll be like it was before’. We now produce about 2,000 litres of treated water every day.”  

Cattail plants help to create a self-sustaining wastewater treatment system. Image: Omiflo

In the future Sio hopes to build a country-wide system that provides a solution for the network of trucks that empty residents’ septic tanks. According to Sio, the drivers are paid to take the waste to a proper treatment facility, but many dump it in nearby rivers instead. Omiflo has also had interest in its solution from south-east Asia and Mexico, where the company is working with another What Design Can Do finalist on a project. Eventually the team aims to develop a licensed solution that’s almost ‘plug and play’.

“We want to build models that can be duplicated everywhere,” Sio says. “We can only do so much work in Kenya, but the problem is prevalent throughout the developing world. I want to change the perception of wastewater. It’s not waste; it can be very valuable, even beautiful.”

Main image: Omiflo

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