Recycling for health

Stoneridge resident Benhilda Mutungira works at her composter, which converts biodegradable waste into bio-fertilizer using earthworms. Zimbabwe, 2022. © MSF/Manzongo John

Nicole Gazard Communications manager

“It’s not waste until you waste it!” reads the sign in front of the towering water tanks in Stoneridge, a community on the outskirts of Zimbabwe’s capital, Harare. Together with residents, Doctors Without Borders/ Médecins Sans Frontières (MSF) has devel- oped a system that recycles food waste and wastewater, which has had a meaningful impact on people’s health.

While working with communities in Harare to identify the medical and environmental challenges they face, MSF teams saw an opportunity to tackle two big issues in Stoneridge. First, how to deal with biodegradable waste like food scraps, which can fill up dump sites and water pipes quickly and be expensive to remove. Second, how to recycle wastewater to prevent groundwater contamination and the spread of waterborne diseases like typhoid and cholera. Collaborating with people living in Stoneridge, MSF launched a pilot project with 32 households in 2019.


For the recycling of biowaste, the solution was elegantly simple. MSF teams installed composters and supplied the earthworms needed to transform that waste into biofertilizer, called vermicompost. This is the result of the natural digestion and excretion process of earthworms.

While biowaste is reduced, organic fertilizer is produced, which can be used for household food gardens or sold for extra income. With the natural reproduction of earthworms within the composter, there is also a market to sell earthworms to people who are new to composting.

“The compost we make is very good for crops and vegetables,” says Farai Wafawareva, a Stoneridge resident and owner of a composter.


To recycle wastewater, MSF teams replaced old septic tanks with decongesters, which separate grey water (wastewater from washing and bathing) and black water (wastewater from toilets). This wastewater then passes through the decongester and is recycled via the wastewater station. The recycled wastewater is chlorinated and reused for watering gardens and flushing toilets.

“We used to have poor toilet systems,” says Wafawareva. “Those old septic tanks had a danger of contaminating the ground. We now have all our waste being piped, so there’s no contamination of the ground or the water. We’re proud to have such a good system, a good environment and good flora and fauna.”


North of the green oasis of Stoneridge lies Mbare, one of the most densely populated areas of Harare, where trash and poor solid waste management practices are a constant health risk.

“Mismanaged waste or garbage can clog stormwater drains and sewer lines, resulting in stagnant bodies of water and flooding. This creates unsanitary conditions that can lead to diarrheal outbreaks like cholera and typhoid,” says MSF project coordinator Danish Malik.

Harare creates over 70,000 tonnes of solid waste each year, so setting up the Mbare Waste Transfer Station was a priority for the MSF team. The community-led initiative offers direct local benefits. Households and businesses like fast-food restaurants can separate their recyclable waste and opt for it to be collected and recycled at the station. As well, recyclers looking to earn extra income can collect recyclable waste or sort through waste at the station and exchange it for cash.


Training was done with a local wastewater management company to help mobilize the community.

“Fifty of us were trained on waste management in the community. We then transferred the knowledge by teaching other community members,” says Blantina Masvosva, a recycler from Mbare. “People in Mbare community are no longer throwing litter everywhere. They can bring in the separated litter and get extra income to fend for their families. I now understand that there is money in litter.”

“We’re proud to have such a good system, a good environment, and good flora and fauna,” says Stoneridge resident Farai Wafawareva.
Zimbabwe, 2022. © MSF/Manzongo John
A resident pours a liquid called ‘worm tea’ over the bio-waste to remove unpleasant smells from the composter and speed up the
composting process. Worm tea is made by soaking worm manure in water, which creates a liquid that is rich in nutrients and can also be
used as liquid fertilizer. Zimbabwe, 2022. © MSF/Manzongo John

As a medical humanitarian organization, MSF’s goal is to reduce the spread of waterborne diseases in the area.

“So far, we have seen zero contamination of the groundwater at the locations where we have implemented the project, which means we are bending the curve of waterborne diseases,” says Ignations Takavada, MSF environmental health supervisor.

But the benefits go far beyond diminishing diseases, proving environmental health initiatives must be integrated into our health projects for long-term sustainability.

“These projects have enormous benefits, not only for public and environmental health,” says Malik. “They also provide sustainable, hygienic sanitation, green employment and income generation opportunities, soil fertility and reduction in total costs for local authorities to manage the waste.”