On an overcast morning in Nairobi, commuter buses drive down a crumbling road into Kibera, a densely packed slum. A sign at the bus station reads “public toilets,” but the doors are locked.

It’s estimated that Kibera has just one toilet for every 2,500 of its approximately 250,000 residents. Without toilets to relieve themselves, people “use any means, whether it’s a [plastic] bag or a can,” explained Fred Amuok, Community Liaison for a Kenyan rights-based organization called Umande Trust.

The World Health Organization estimates that 1.5 million people die every year from diarrhea, often the result of poor sanitation. There’s also a financial cost: studies show that Kenya loses US$324 million each year in missed work hours due to sickness brought on by poor sanitation. According to the sanitation company Sanergy, four million tonnes of fecal sludge escape into Kenya’s waterways and fields every year.

But Umande Trust has come up with an innovative approach to providing affordable toilets for Kibera’s residents and turning human waste into cooking fuel–one that’s already been working for more than a decade.

Read the full story as it appeared on Impact Journalism Day 2016 at Solutions&Co by SparkNews.