Martha’s Flexigester African adventure

Martha Stokes working on a new biogas sewarage system in Tanzania
Martha Stokes working on a new biogas sewarage system in Tanzania

East Africa TV and newspapers have been interviewing Reston’s Martha Stokes about the world’s first biogas producing simplified sewerage system she has been involved with in Tanzania.

For the past two months Martha, a recent natural sciences graduate from the university of Cambridge, Christ’s College, has been in Dar es Salaam working on the Cambridge Development Iniative (CDI) - connecting a biogas tank to a pre-existing simplied sewerage system to harness the methane from the sewage and transform it into biogas for cooking. A system they hope will eventually be used all over Africa.

Last year, CDI and Tanzanian students from Ardhi University fitted simplified sewerage systems in Tanzania for the first time.

“What we are doing is taking a social and environmental problem - the problem of poor sanitation - and creating a business solution. Now, the system will recycle waste and produce biogas which the community can sell,” said Mapinduzi Nkonya, an engineering student from Ardhi University.

Currently 80% of the population of Dar es Salaam live in urban informal settlements that have inadequate sanitation which means the city has high rates of cholera, malaria, lymphatic filariasis, dysentery and diarrhoea.

Simplified sewerage was developed in the early 1980s and is now widely used throughout Brazil, Honduras and Pakistan but it has yet to break through in Africa.

The team Martha is working with has taken it a step further by adding the Flexigester V10 anaerobic digestion system which converts human waste into an energy source.

Martha said: “This physical network is complemented by a community mobilisation and hygiene programme. Right from the beginning, we made sure to involve the community - they shaped the project. They have a community association to ensure that the network is looked after for years to come.

“It has been really interesting to learn about a community focused approach from local organisations in Dar es Salaam. I completely agree with projects that centre themselves around the needs of people, rather than expecting people to centre around the project. It’s been great.”