Etudes de cas
Otji toilets for peri-urban informal households
This case study is about pilot scale urine diversion dehydration toilets for periurban informal households in Omaruru, Namibia implemented by GIZ on behalf of the German Ministry BMZ. The project was designed to show the advantages of dry sanitation systems in arid regions such as Namibia. It aims also to involve the local authorities in such a way that they can implement sanitation facilities in the future based on the findings of the pilot study. To provide access to safe, affordable sanitation for all Namibians, it is essential to consider dry sanitation as a proactive measure to water shortages and as a way to save precious water resources in the wake of climate change.
The Otji toilet is based on dehydration and was considered especially suitable for a region with intense solar radiation and low precipitation. The ventilation and dehydration of the collection container content (90 liter container) is driven by the sun. The urine diversion toilet bowl is designed in such a way that urine touching the wall of the bowl is collected in a small trough, drained away through a pipe and infiltrated into the ground. Alternatively, the urine could be collected in containers and stored for reuse. No problems of blockages of the collection trough or the urine pipe, which is 20 mm in diameter, have been reported. The dried faeces can be used as soil amendment or can be co-composted with other biodegradable material. Greywater from the attached handwashing facilities is collected and used for irrigating gardens.
The main expected impact of the project is to provide relevant information for decision makers and to persuade them about the necessity of saving water by introducing appropriate sanitation systems.
Kleemann, F., Berdau, S.
Sustainable Sanitation Alliance (SuSanA)
UDDT, GTZ, dry, local authorities, Omaruru, ventilation, dehydration, urine diversion, UDS, Greywater, high acceptance
Kleemann, F., Berdau, S. (2011). Otji toilets for peri-urban informal households - Omaruru, Namibia. Sustainable Sanitation Alliance (SuSanA).