Alex Rose-Innes
For several years the International Water Security Network (IWSN) had been conducting water research in Kisoro, Uganda. Focus had been on water quality and rainwater harvesting tanks. The ISWN roped in community leaders and members of the water and sanitation programme in the area to build a gravity flow scheme in Gitovu, a village nearby.
Last year, the Global Challenges Research Fund, in conjunction with the Lloyd’s Register Foundation sponsored the project with the condition that this water scheme should provide not only water services, but to also act as a research platform into socio-technologies of water in remote, underserved communities. The villages of Rurangara, Gitovu, Bugara and Gatera would benefit from this scheme.
The discussions with community leaders highlighted various main objectives:
- Dealing with land issues, responsibilities and information regarding the project;
- obtaining community buy-in and permission for the technical field survey team to have access to private residential homes for development and design purposes;
- feedback from residents of Rurangara, location of the water source and
- determining the amount of water to be tapped and collected from Nyarutembe in Rurangara.
Communities had various requests such as for money and jobs, but most offered support for the project. With as much as 16 000 litres of water collected in a day, more than 2 000 residents in three villages were to benefit from the project. The World Health Organisation (WHO) standard of 15 litres per person per day could not be met and more than one water source was needed.
A private supply in Nyarutembe was identified and with all community role players on board, it was decided to construct small reservoirs along the route to the final destinations. Local communities which were to benefit undertook to obtain and deliver materials for the gravity flow scheme development and ensure works were undertaken to completion.
The IWSN undertook to train user committees before final commissioning and handover of the completed scheme to beneficiary communities.
Ceramic pot filters, a cheap option to treat stored rainwater
A lack of access to safe water in many parts of Africa calls for rainwater harvesting to be explored and developed. However, this could pose a health risk because of bonding to chemicals in the air before falling on roofs, drainage gutters and pipes and sometimes in the storage tanks themselves.
To improve quality of stored drinking water, ceramic pot filters (CPF’s) had been identified by the IWSN as a technological solution. Ceramic pores become pathogen barriers and its effectiveness had been measured at removing >99% of protozoa and 90-99% of bacteria. CPF’s could also work via adsorption and biofilm metabolism with a 60-70% reduction in diarrheal disease incidence.
Supported by the UWE Global Water Security Programme, Joshua Oldfield, a BSc Geography student at the University of the West of England investigated hydraulic properties of CPF’s associated with removing bacteria in stored rainwater in Kisoro, Uganda in Africa. Here, more than 90% of the population is living in rural areas among mountains with no access to piped water. Less than half of the residents consume safe water.
For his research, Joshua worked with water engineer Alan Cook and Dr Tavs Jorgensen, Associate Professor and AHRC Leadership Fellow at the Centre for Fine Print Research, to manufacture prototypes of three types of ceramic filters.
In addition to testing for total coliform in the filtered sample, Joshua also conducted hydraulic and visual investigations using a Scanned Electronic Microscope (SEM) to examine porosity size and flow rate, which affects the achieved water disinfection effect. He found that controlling the porosity of the filter seems to be key to successful CPF’s, balancing off flow rate against treatment efficacy.
