Sanitation woes are helping to fuel green energy in Kenya's largest slum, where human excrement is being transformed into an asset.
Kenya's growing urban population has made it difficult for the government to tackle sanitation, with an urgent need for innovative solutions.
In Kibera slum, seven kilometres from Nairobi, human waste is being turned into biogas thanks to initiatives supported by the community, the Health Ministry and others.
Tree Hill School is one of nine bio centres – sanitary blocks that use a biodigester system to treat waste and produce biogas – that has been opened.
It has backing from the Umande Trust civil society group and other partners including the French Development Agency.
Benazir Douglas, of the Umande Trust, said her team looked for ways the community could make money from efforts to make their surroundings healthier and safer. Using readily available items, such as fecal matter, made sense.
"They not only collect money from the sale of biogas but also through a small fee from members of the public who use these toilets," she said.
Teachers, locals on board
Tree Hill teacher Rose Muthoni said enrolment had increased since the bio centre's opening had spurred a food program and improved sanitation conditions. However parents were reluctant at first.
The school previously had only two toilets.
"Maintaining hygiene was a challenge. Parents were scared to take their children to this school; it was not clean enough. Now they can get food cooked from their waste and access very clean toilets,'' Muthoni said.
A neighbouring grocer, James Kariithi, said he often visited the bio centre.
"With only five shillings I can use a clean toilet. I can also get a cup of hot tea. Isn't that strange and amazing?" Kariithi told RFI.
The centre serves around 100 community meals per day on top of 150 meals prepared for pupils.
Junior Masinde, an attendant at the bio centre, was once against using it for cooking, thinking it would make the food smell.
"I am still surprised they use this [biogas] for preparing meals. It took me time to start eating anything cooked here,'' they told RFI.
Umande Trust often carries out awareness campaigns to educate the community on biogas.
Results of poor sanitation
Kenya has been grappling with untreated human waste released into the environment through so-called "flying toilets" – faeces put into discarded plastic bags – and open defecation.
The UN estimates that poor sanitation costs an annual global GDP loss of $235 billion euros. Environment experts argue for a collective approach to sanitation challenges to acheive the Sustainable Development Goal of clean water and sanitation for all by 2030.
Yet, access to clean water to run bio centres remains a challenge. Some centres are forced to buy water for cleaning the facilities from vendors, an overhead that effects their profits.
Nairobi public health officer Joe Okello told RFI there is more that to be done to acheive clean water and sanitation.
"Innovative approaches and community involvement is the best approach Kenya can employ," he said.