Climate Adaptation & Low-Carbon Housing Challenge



Omiflo combats severe wastewater pollution using energy and chemical-free systems that convert wastewater to clean water using natural plant-based biotechnology.

Team Lead

Mshila Sio

Solution Overview & Team Lead Details

Our Organization


What is the name of your solution?


Provide a one-line summary of your solution.

Omiflo combats severe wastewater pollution using energy and chemical-free systems that convert wastewater to clean water using natural plant-based biotechnology.

Film your elevator pitch.

What specific problem are you solving?

Developing nations suffer from a severe lack of wastewater treatment infrastructure. Rapid, unplanned urbanization has overwhelmed municipalities, resulting in them being unable to provide sanitation services to ever-growing populations. Urban populations are growing exponentially faster than sewage infrastructure can cope. In most countries, on-site sanitation systems predominate. The fastest-growing urban areas would need to build out their sewer systems at a rate that is 10-50 times higher than the highest rate for any project in the World Bank’s database.

This service gap is primarily filled by vacuum trucks/services (stool buses) that extract septage and transport it to designated dumping sites. Unfortunately, around 96% of this septage ends up on the open ground or in surface waters due to a lack of viable treatment solutions. 

This challenge contributes to some of the biggest issues facing people living in poverty. Almost 2 billion people use a source of drinking water contaminated with faeces, and up to 80% of illnesses in the developing world are linked to inadequate water and sanitation.

Secondly, urban and peri-urban residents, who have to rely mainly on on-site sanitation systems (OSSs) pay the highest rates for sewerage services. The vast majority rely on private operators to extract their sewage for disposal. OSS cost is borne mainly by the user as opposed to sewered systems that the municipalities bear. Households pay around 4% of the total lifecycle cost of sewered systems vs 84% of OSS systems (including extraction). This service is provided by thousands of exhauster/vacuum trucks that empty waste, the majority of which is dumped entirely untreated. Over 80% of residents in primary towns in Africa, and around 98% of residents in secondary towns use OSS. Investments in the respective stages, such as the safe collection, disposal and treatment from OSS present a significant challenge due to the unattractive economics of conventional treatment technologies.

Finally, the environmental impact is immeasurable. Studies have shown that water pollution has worsened in almost all rivers in Africa, Asia and Latin America. This has resulted in dead rivers which harm aquatic life, the environment & wildlife, and contributes significantly to the deoxygenation and acidification of our oceans.  In addition to microbial and chemical pollution, untreated wastewater released into the environment generates 3 times the GHG of wastewater treated in a conventional plant.

The central problem we are addressing is the lack of infrastructure and treatment sites or disposal options for the discharge that comes from on-site sanitation. Private trucks dump where most convenient, including streams, rivers, waterbodies, open grounds, and bushes, thus creating environmental and public health hazards.

What is your solution?

We aim to tackle this problem with decentralized, small-scale treatment sites that convert septage into clean water for discharge or reuse. We will provide low-cost, sites within these high-density towns with little or no access to sewer treatment. 

This will be accomplished through the use of our treatment technology which reduces the financial and operational barriers that prevent the widespread adoption of wastewater treatment systems. Our system is a plant-based biotechnology system that combines phytoremediation and hydroponics principles to recycle wastewater more effectively and sustainably than conventional technologies. 

Our innovation uses no energy or chemicals, eliminates smells entirely, and provides high effectiveness in a significantly smaller footprint than open ponds or constructed wetlands. The system is self-sustaining with no moving parts making it robust and sustainable. We deliver the effectiveness of electro-mechanical systems without their entry and operational barriers. We reduce the need for costly infrastructure or technical expertise usually required to benefit from wastewater treatment. 

We achieve this by using a proprietary “Water Planting System”. This system floats emergent aquatic plants like "Typha Dominguensis", on top of the contaminated water body that’s to be treated. These plants capture oxygen from the atmosphere through their leaves and channel it through their roots, depositing oxygen in contaminated waters and thereby starting the oxygenation process responsible for water purification in a wholly natural manner. Our innovation enhances nature-based wastewater treatment systems by up to 10 times. through the creation of an artificial wetland of flotation macrophytes, which are responsible for purifying the waters.

One of the unique features achieved by this approach is the successful floatation of extremely tall Typha and similar cattail species of up to 3 meters and deep roots of up to 1 meter. This allows for outstanding water treatment capacity, aeration and nutrient uptake. The plants operate autonomously and adapt to live in wastewater creating a smart self-sustaining ecosystem.

The “water planting system” is a specially designed piece of hardware made from 45% recycled plastic. This is a modular unit, that floats the plants on the contaminated water. These units are designed to join together forming a tessellation of varying sizes for scalable treatment requirements from a single household to a municipality. They can host small seedlings and support large 3m tall plants weighing up to 40kgs per square meter.

We aim to develop decentralized reception and treatment centres for on-site sanitation, sewage and faecal sludge in areas with limited or no access to a sewer line or municipal treatment system. The individual projects will be able to receive 20-50 trucks/day and create a green space that can treat septage from the trucks to safe discharge standards. 

Upon completion, we will have created a self-sustaining green space that sequesters carbon, improves the surrounding environment and creates income-generating opportunities. In addition to that, we will generate renewable resources like water and biomass that can be used for feedstock and related activities.

Who does your solution serve, and in what ways will the solution impact their lives?

Our beneficiaries are urban/peri-urban residents who rely on on-site sanitation systems and the target market is sanitation operators that serve them. We will provide treatment services for these operators that will have benefits across the sanitation value chain. 

Our approach will result in significant savings for the extractors of septage by reducing travel time, fuel, vehicle operations & maintenance and dumping fees. In Africa, these costs account for around 79% of operational costs. 

We will empower extractors to access more affordable and convenient treatment sites. This will lower the cost for all parties whilst simultaneously increasing profits for extractors.

The impact we will have is the development of a duplicable, scalable technology that is also financially sustainable due to the low operational requirements of our technology. These trucks need conveniently located, affordable dumping sites and municipalities are proactively seeking investments in this sector.

The projects will increase the income opportunities for the truck operators, we will reduce travel time for trucks from 3-hour round trips to 30 minutes. This will reduce fuel consumption, and emissions and reduce illegal dumping by providing easily accessible sites, and give users assurance of adequate treatment of their wastewater.

We believe this project presents a value proposition for stakeholders as follows.

Stakeholder (a): Community/Municipality The community will secure investment into infrastructure that provides a much-needed service with the following benefits:

• Compliant disposal option of septic waste.

• Improved water quality downstream

• Improved public health

• Preserved ecosystem

• Promotion of innovation in faecal sludge and wastewater management.

Stakeholder (b): Exhauster trucks/stool bus:

Exhausters will benefit from improved convenience, cost savings & increased revenue: The trucks will be travelling shorter distances between trips. This will also reduce the temptation to dump waste illegally. 

Stakeholder (c): Omiflo & Funders:

• Funders have an opportunity to invest in an eco-project with high social impact and sustainable long-term income.

• Omiflo utilises local plants, components and labour to build all their systems.

Truck drivers will benefit directly from the project. They are one of the key players in the sanitation value chain. They collect and dump sewage from residents and nearby communities. We will sensitize them to the effects of untreated wastewater from illegal dumping and communicate the benefits of using ecosystem-based solutions within their community. The projects will reinforce the sanitation supply chain by reducing costs for the users and transporters, and by providing access and training to marginalized groups. 

How are you and your team well-positioned to deliver this solution?

We witness on a daily basis the terrible effects that untreated wastewater is having on our environment and community. The rivers around our community are a source of disease and distress. They should a source of life, livelihood and regeneration. We are driven by the knowledge that water scarcity affects 1 in 3 people worldwide. People use the wastewater we dump to drink, bathe, and grow their vegetables. This situation is unacceptable. On the other hand, we work every day with excitement, knowing that our work is helping to solve this problem in a very tangible, uplifting, and dignifying way. We have prioritized technology that can be built and sustainably managed by the communities it serves, that converts one of our biggest burdens into a valuable resource that improves people's health, and livelihoods and will have an impact for decades to come.


We built a small biocentre in Nairobi, which is a unique space that is a living example of a waste-to-value community.  We love this space because it is a showcase of what is possible when we embrace good ideas and new technology. We took all the wastewater from surrounding houses by bypassing their septic tanks. We directed this into our pilot wastewater treatment system and with time we have turned it into a stunning green space that gives us 3,000 litres a day of water. This water is used for irrigation of a small farm and keeping our lawns green. We created a thriving ecosystem from recycled water. We have unique birds and small animals that we didn’t have before. Our entire team is partially fed from our small farm and all our guests leave with some vegetables. In addition to that, we use our food waste to produce biogas for cooking in the office. This is our showcase project and has been the catalyst for exposure of technology to clients, environmentalists, NGOs, government etc.

Which dimension of the Challenge does your solution most closely address?


In what city, town, or region is your solution team headquartered?

Nairobi, Kenya

What is your solution’s stage of development?

Growth: An organization with an established product, service, or business model that is rolled out in one or more communities

How many people does your solution currently serve?

We have been able to provide wastewater treatment solutions that serve over 4,000 every day and growing. Our systems eliminate pollution that contaminates ground and surface water which is destroying our rivers and the livelihoods of people downstream. Since inception, we have prevented over 120,400m3 of water from contaminating our environment. We have provided over 20,650m3 of recycled water that has been used for food production, car washes, tree nurseries and fish farming. We have also created employment and income opportunities related to reclaimed water that was previously unattainable.

We have built systems for eco-tourism and conservation champions like Africa Fund for Endangered Wildlife, The Maa Trust, research and development organizations such as International Livestock and Research Institute and schools and humanitarian organizations like Samburu Girls Foundation. We have received acknowledgement/awards from the Kenya Climate Innovation Centre, USADF, Aqua for All and What Design Can do. Our results have been accredited by government laboratories to meet safe discharge standards.

Why are you applying to Solve?

We have developed a very useful technology and we are delighted with our results so far. We have however become increasingly aware that we are not addressing the bigger problem that our community is facing and we are looking for technical and financial support to address our solution to the wider challenge.

Our current model serves B2C clients where we design and build systems on-site. We aim to continue growing this model but it is clear that we need to pivot to provide the B2B services as follows. 

The vast majority of Africans in growing urban areas will continue to use on-site sanitation like septic tanks. They are served primarily by exhauster trucks that take their sewage for subsequent dumping. We aim to build reception sites for these trucks and charge a fee for dumping and recycling that sewage.

The existing solutions are plagued by the following challenges. They are highly mechanized, energy-intensive systems that are complex to operate and require high capital. Alternatively, nature-based systems have vast land requirements and provide logistical difficulties. The unpleasant, unsightly nature and negative effects on public health of conventional systems, meaning they have to be built far from population centres. This prohibits the widespread collection and treatment of sewage.

We are seeking funding to build reception systems for these trucks and will generate revenue from dumping fees and auxiliary services. e.g. trucks in Africa pay between $8-$18 dollars per dumping event.

In which of the following areas do you most need partners or support?

  • Business Model (e.g. product-market fit, strategy & development)
  • Financial (e.g. accounting practices, pitching to investors)
  • Monitoring & Evaluation (e.g. collecting/using data, measuring impact)
  • Product / Service Distribution (e.g. delivery, logistics, expanding client base)

Who is the Team Lead for your solution?

Mshila Sio

More About Your Solution

What makes your solution innovative?

The existing solutions are plagued by the following challenges. They are highly mechanized, energy-intensive systems that are complex to operate and require high capital.  Alternatively, nature-based systems have vast land requirements and provide logistical difficulties. The unpleasant, unsightly nature and negative effects on public health of conventional systems, mean they have to be built far from population centres. This prohibits the widespread collection and treatment of sewage. 

Omiflo uses a fraction of the space required by wetlands and stabilization ponds. Our solution creates green spaces that can treat septage and sludge to safe discharge standards and can be installed right next to the population it serves due to the elimination of unpleasant odours. We offer an affordable and more environmentally responsible model for the movement and treatment of septage. The system can be built fairly quickly and managed by the community it serves.

In addition to the improved infrastructure of our approach, our solution aims to incorporate tech-enabled decentralised collection and treatment systems to accelerate the growth of the technology. People will be able to order trucks from their phones. 

The sites generate will revenue from dumping fees and the sale of recycled non-potable water. This will make them technically and financially self-sustaining.

What are your impact goals for the next year and the next five years, and how will you achieve them?

We want to be the most impactful wastewater treatment company in Africa by creating a sustainable process for the collection, transportation and treatment of sewage for the hundreds of millions who are not connected to sewer lines. We will develop a platform that connects users, trucks and treatment plants. 

We will develop a licensing model to accelerate growth, for independent operators across active markets. Initially targeting 15 sites in selected cities & towns in Kenya. Later expand the model outside Kenya to build & licence 40 additional sites across East Africa and West Africa by 2025.

Which of the UN Sustainable Development Goals does your solution address?

  • 6. Clean Water and Sanitation
  • 9. Industry, Innovation, and Infrastructure
  • 11. Sustainable Cities and Communities
  • 13. Climate Action
  • 14. Life Below Water

How are you measuring your progress toward your impact goals?

We currently have a very quantitative approach to measuring our impact.

The first one addresses to the amount of contamination we have prevented from being introduced into the environment. This includes water quality parameters including chemical, physical, and biological properties are monitored based on the desired water parameters of concern.

We estimate a BOD5 reduction of 122 kg/day from our projects. This high BOD5 would otherwise have consumed oxygen levels in the receiving water bodies if discharged untreated.

The second addresses responsible and sustainable use of resources and circular economy. This includes

The volume of water treated. 223,000 litres/day

The volume of water reused/saved. 32,000 litres /day

We also estimate that our projects sequester 3000 kg/c annually 

What is your theory of change?

Our long-term goal is to develop several decentralized projects that receive wastewater from the thousands of exhauster trucks serving people who are not connected to a centralized sewage treatment system. Our projects will treat this wastewater to reusable standards for responsible discharge or reuse. They will also create healthy green spaces for the communities that they serve.

In Kenya, over 17 million people currently live in rapidly growing urban population centres. Many of these have no centralized wastewater system and have poor urban plans to cater for this growth. The majority of them use septic tanks, including large storied buildings, which are subsequently served by 1,000s of exhausters. These exhausters have limited access to suitable unloading points, so they either dump their load in sewerage systems that don’t work, are over capacity or they often they dump illegally in rivers, quarries or directly on the ground. We will change how this industry operates by offering convenient, decentralized wastewater reception points in town centres.

The key to successfully implementing decentralized receptors for exhausters is based on 3 aspects.

First, the systems have to be conveniently located. Dumping sites need to be within a few minutes drive of the population being

3 served. With our systems, exhaust trucks travel much shorter distances, allowing for cost savings and increased opportunity to make multiple trips/day. This will also significantly reduce the temptation to dump waste illegally.

Secondly, the system must have reasonable investment and operational requirements to sustain itself and pay back investors. Our systems require lower capital input than conventional systems due to the simple construction methods required, the significant reduction in the size of land and the simple non-mechanical operational requirements.

Thirdly, the system must be pleasant for the surrounding community, extremely reliable and cater for significant variations in load and volume. i.e. during rainy seasons, exhauster trips increase significantly. Our systems operations do not encounter drastic changes with these load variations. E.g. drastic changes in energy or chemical input that would hinder, or cripple mechanical systems.

Each project will sustain itself with the revenue generated from charging exhauster trucks to dump their load.

Our solution presents a win-win solution for all stakeholders involved.

The local governments will secure private investment into much-needed infrastructure that serves the public. They will experience improved environment, and public health and create employment and business opportunities.

The exhausters will benefit from operational savings, increased revenue and reduced temptation to dump illegally.

The investors have an opportunity to invest in high social impact projects that have reliable cash revenues and improve the environment.

Our projects will generate economic, social and environmental value.

Describe the core technology that powers your solution.

There are 3 key components to our technology.


  1. The plants
  2. The floatation system
  3. The lagoon/pond design.

Our technology works on the same principles of conventional treatment systems, except that we combine innovative hardware and specialised biotechnology to inject oxygen using plants.


  • Plants:
  • Floatation system.
  • Lagoons/pond 


Plants have been used in water treatment (phytoremediation) for centuries around the world, including in modern systems like constructed wetlands. Omiflo takes plant-based water treatment to the next level with the introduction of the floatation matrix, a scalable hardware unit that puts phytoremediation plants into floatation onto the surface of the wastewater lagoons to form a “Floating Green Filter”. This plant-based treatment filter uses similar plants to a constructed wetland, but rather than planting in gravel, the floatation matrix allows plants to be installed directly on the water surface.


Macrophytes have special characteristics making them ideal for application within the system. Firstly, they have a lower density than water (0.6-0.7), so while the Bio-Matrix flotation hardware is vital to ensure stability, viability and easier maintenance, as they grow larger they do not require additional aid to maintain their buoyancy.


Secondly, as the plants develop they spread and form a dense root structure that aerates the water. It is powered by both photosynthesis and isostatic differential pressures between the air-channels of the plant and the atmosphere (21% Oxygen). This secondary method of aeration due to the plants' physiological alveolar type continues to function even during the winter when leaves are dry and the vegetation stops.


Additionally, the aerated root structures become an ideal habitat for microorganisms, which break down contaminants in the water. They also drastically reduce the number of pathogenic microorganisms due to the presence of predators ( protozoa and bacteriophages ) in the rhizosphere of the plants. Finally, minerals and heavy metals are fixed by the plants in their structure, and components such as phosphorus and nitrates are absorbed directly.


This has allowed us to replace expensive and energy-intensive aeration machines with aerating plants, which use photosynthesis to convert C02 to oxygen for aerobic bacteria. Rather than suspended bacteria, bacterial communities form higher-performing fixed bacterial biofilms on the dense aerated root structures.


The floatation system and macrophyte density


The average density of the macrophyte is around 0.6, with the average density of the leaves being 0.3 and that of the roots being 0.85 with respect to that of water. The macrophyte has the ability to float on its own but is not capable of holding itself vertically, therefore a floating system i.e. artificial soil (Omiflo floatation System) must be supplied through which a floating carpet of Macrophyte plants can be formed.


This physical property is essential to know how to apply it well, to achieve maximum effectiveness of the treatment plant, that is, to maintain the optimization of the treatment process for a long period of time


Reduction of the BOD and COD of the water, by the macrophyte


The reduction of the BOD and COD occurs on the entire surface of the macrophyte that is in contact with water (roots, rhizomes and in the area of the leaves or stems that are submerged) since they take the oxygen they need from the microorganisms that they feed on both dissolved and undissolved BOD.


Optimizing the performance of the macrophyte root and leaf system



Omifloso systems use a proprietary floatation system which is a specially designed flotation aid for planting floating macrophyte plants. These help to stabilize young macrophytes and prevent them from tipping over, thus improving their viability. Additionally, they improve installation efficiency and ensure even growth across the filter. They have high buoyancy and flexibility, are strong, and have connection points that allow for scalable installation and good plant distribution.  


The floatation device is made from 45% recycled plastic. It is a simple device that hosts plants throughout their lives. Individual units are assembled to form a mat on top of the wastewater. The units are identical and are assembled (like Legos) to form a tessellation. 


The plants selected have a lower density than water and therefore work in synergy with the floatation aid. They self-regenerate over time which means they do not require replacement. They create a smart eco-system, where they rely on the wastewater for their nutrient and in the process provide a self-sustaining system for wastewater treatment. 




For our technology, we adopt the type lagoons (anaerobic, optional and maturation) of conventional lagoon-type purification systems, although the size requirement is less than 20% of what is used in these lagoons. In this way, we will eliminate one of the biggest drawbacks of this type of conventional treatment plant.]


These are designed based on the volume and parameters of the wastewater and the clients' discharge requirements. Ponds are designed for adequate retention time to allow for all activities to occur with adequate safety margins. We use a dam liner to prevent seepage into the surrounding environment and retain as much water as possible. 


The deep components on the ponds 2.5m+ carry out the removal of carbon, organics and other solids coming into the system. The roots of the floating filter retain all solids, acting as a primary screen that retains and eliminates the larger organic particles that have bypassed the pre-treatment process.


The floating macrophytes initiate the oxidation processes due to oxygen transfer from the plants to the water. The first pond works with aerobic and anaerobic processes occurring within the same pond. This approach enables an efficient reduction of BOD, TSS, and COD while eliminating sludge in the lagoon.


Pond 2. Mid depth ponds. The bed of roots in this pond comes into contact with more of the effluent, infusing oxygen which creates a rich pool of aerobic micro-bacteria. This will completely prevent the occurrence of anaerobic decay and consequently will produce a safe system for the digestion of organic matter dissolved in water directly to CO2.


Final pond. Shallow 1m This pond is shallow to force intensive contact with the roots of the filters as they occupy the entire volume of the pond. This process improves nitrification by the assimilation of nutrients (nitrates, phosphates, dissolved metal ions, etc.); in the process, coliforms are also eliminated. The resulting effluent is very high quality and is practically available for reuse. This process may be complemented by the simple use of sand filters or more complex processes (chlorination, ultraviolet, active electrical hydrolysis, etc.).


The microbial flora is very active in this pond because there is a large amount of dissolved oxygen from the continuous pumping through the plants' leaves.


Which of the following categories best describes your solution?

A new application of an existing technology

Please select the technologies currently used in your solution:

  • Ancestral Technology & Practices
  • Biotechnology / Bioengineering
  • Manufacturing Technology
Your Team

What type of organization is your solution team?

For-profit, including B-Corp or similar models

How many people work on your solution team?


How long have you been working on your solution?

6 years

What is your approach to incorporating diversity, equity, and inclusivity into your work?

Our team is extremely diverse in ownership and leadership. We are a majority women-owned company (slightly) and by the nature of our work, we have taken on board and trained several people previously classified as unskilled labourers. 

We employed and trained unskilled labour in the development of our technology and we continue to do so. In addition to that, we also endeavour to employ young people during project implementation. Our system is very applicable to marginalized communities and its benefits are easily appreciated regardless of literacy levels. In addition to the direct sanitation improvements our systems offer, we have created new roles/jobs and income-generation opportunities for women and marginalized groups. Women and girls carry much of the burden of the lack of sanitation facilities and water contamination, affecting their health and hygiene, safety, education, and quality of life. We have reinforced the sanitation supply chain by reducing construction costs for the poor and providing access to wastewater recycling systems as well as training and education.

Your Business Model & Funding

What is your business model?

  • Our revenue comes from designing and constructing our systems on a per-project basis. We are building a small revenue stream from the maintenance of the systems. 
  • We price our systems based on the size, cost of materials, length of the project and location.
  • We are not yet cashflow positive but we are tracking positively and plan to accomplish that by the end of this year 2023.
  • We plan to develop service/utility-like projects where clients hire us to handle their wastewater at a fee. E.g. monthly or volume based.
  • We plan to develop dumping sites for vacuum trucks that deal with on-site sanitation challenges. These will generate revenue from dumping fees.
  • Our main costs are salaries, office and biocentre operational costsproject implementation costs, mainly in the construction stage and later minor ongoing maintenance costs.
  • Our most expensive cost is the production of the floatation matrix due to the cost of acquiring plastics and the minimum order requirements. 

Do you primarily provide products or services directly to individuals, to other organizations, or to the government?

Individual consumers or stakeholders (B2C)

What is your plan for becoming financially sustainable?

Our existing projects are turnkey projects with one-off project revenue. We are therefore reliant on the frequency and size of projects for sustainability. We intend to improve our sustainability by building utility models, e.g. truck reception projects that will provide us with reliable recurring revenue for the foreseeable future. In addition to that, we will have developed a duplicable model for scaling and wider impact.

Share some examples of how your plan to achieve financial sustainability has been successful so far.

We have managed ourselves through revenue from projects, small grants and funding from family businesses. 

  • 2020 Revenue -  $32,192
  • 2021 Revenue  - $20,925 -25% decrease (covid19 affected year) 
  • 2022 Revenue  - $52,313 - 150% increase

We have received 2 grants to date from USAID, Via Water/Aqua for all and an award from the No Waste - What Design Can Do.

We have also received angel funding through a sister company owned by family members.

Solution Team

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