Gravit`eau Water Kiosks in Uganda

Gravity-driven membrane (GDM) filtration - is a novel technology to disinfect water with a potential to overcome many limitations of the existing systems. The core element of the filter is a membrane with a pore size of 20-40 nm. When biofilm is allowed to form on the membrane, water flux stabilizes at 4-10 litres per hour per square meter of membrane and filters do not clog. GDM systems can be operated for 8-10 years, even with very turbid water and do not require backwashing, cleaning or electricity. Filters remove all classes of pathogenic microorganisms including viruses, bacteria and protozoa. Due to their ease of operation and independence of external inputs such as replacement parts, chemicals or electricity, they can be installed in remote areas and be managed by local communities.

Since 2014, five GDM water kiosks have been constructed and operate in Busia and Namayingo Districts in Uganda, on a shore of Lake Victoria. IEC, Eawag (Sandec) and Africa Water Solutions evaluate the technical performance, acceptance and sustainability of the systems. Each water kiosk supplies up to 6000 L of water per day. Water is abstracted from the lake and is delivered to schools located up to 2 km distance from the lake by solar pumping. Water is treated by GDM system at the school and is provided for school children for free and is sold to community for a subscription fee of 1 CHF per month or at a price of 0.015 cent/jerry can. Income generated through sales of water is used for operation and maintenance activities to assure sustainability of the system on the long term.