The pandemic threatens vulnerable families.

Gravit’eau: washing your hands with recycled water

Tdh, Gravit'eau Association and partners are developing the idea of a mobile hand-washing station which uses an automatic water recycling system to deal with water shortages in crisis situations.

Deployed in the context of a pilot project in a camp for displaced persons in Nigeria, this innovative idea has enabled more than 400 children to wash their hands each day, reducing the spread of disease and epidemics.


Did you say Gravit’eau?


Gravit’eau is a system used in mobile hand-washing stations which use a very small amount of water thanks to a self-regenerating system. Waste water is collected in a tank and then automatically filtered by a membrane. The system works by gravity. The technology enables water to be recycled without the use of electricity, without any complex maintenance and without a continuous supply of chemical products. The filtration membrane is so fine that it does not let bacteria or viruses pass through. Water for washing hands flows by means of a foot pump.


“Washing hands reduces 50% of cases of diarrhoea and pneumonia among young children and restricts to a great extent the spread of infectious diseases and epidemics such as cholera and Ebola. Gravit’eau was developed to be a simple to use solution”, explains Bruno Pascual, our expert in water, sanitation and hygiene in emergency situations.


A pilot phase in a camp for displaced persons


The pilot phase took place in Nigeria. In the north west of the country, the conflict between the government and Boko Haram and other armed groups, which began in 2009, brought about a serious humanitarian crisis. The insurgency and the political violence caused a massive displacement of the population to camps where basic needs are not provided. Water, needed for food and drink, is in extremely short supply.


Gravit’eau prototypes have been set up in the Mafa camp for the displaced in Borno state in the areas earmarked for children’s educational activities. Up to 100 children an hour can wash their hands using an average of just 2ml of water per wash. The water in each station only has to be changed once per month. Stations require very little maintenance, a real constraint in this type of context.


Impact and Potential


The initial results from this pilot have proved the importance of a larger scale rollout with a constant concern for technical improvement. To ensure that good practices are employed, we educate and instruct users on the benefits and process of such an approach.


Moving beyond hand-washing, other uses of this filtration technology are being investigated involving larger amounts of water, particularly for processing domestic waste water used for cooking or for personal hygiene.


With the support of