Summary

The lack of improved water sources and adequate sanitation is a global problem. Lack of resources has resulted in 2.2 million fatalities every year due to diseases associated with these environmental conditions.

Madagascar has very limited improved water sources (14% rural, 66% urban) and sanitation coverage (7.5% rural, 27% urban) (WaterAid 2006).
The rural village of Andavadoaka (population 1,200), southwest Madagascar, has improved water sources, but no sanitation facilities. The aim of this study is to investigate the quality of the village’s water supplies to enable the identification of contamination sources, and from this develop a potential sanitation plan using biogas technology.

All available drinking and bathing water sources were sampled in and around the village. These samples were tested for their microbial and  chemical content, specifically designed to indicate the level of faecal contamination. In addition, geological, hydrological, and climatic data were collected on site, as well as the recording of social attitudes.

Microbial and chemical analysis of water samples showed that the Vezo people’s ‘free defecation’ behaviour and unrestricted animal transport had caused gross contamination of many of their water sources.

The pathogenic strain Esherichia coli O157:H7 was consistently isolated in several sites, including the most heavily used wells, highlighting the disease potential of this contamination. Elevated ammonia and nitrate levels as well as the presence of hydrogen sulphide in several sample sites indicated that one of the major sources of contamination was human sanitary waste. The outbreak of cholera in 2000 that made 25 people ill and caused 2 fatalities in the village confirms that contamination has already caused serious health effects.

Water depth measurements indicated the area around Andavadoaka suffered significantly from drought and that what little water provisions were available need to be protected.

A sanitation programme could be successful in Andavadoaka if implemented properly. The Vezo would need to be educated in the benefits of a biogas sanitation plan to create sustainable resources from human and animal waste, as well as improved health and hygiene as a result of effective sanitation.

The amount of feed (human/animal waste) available in the area could run two biogas digesters within the village. The Northern plant could  potentially produce on average 6.3m3/day of methane - enough to run a refrigeration system that could improve the storage capabilities of the fishermen’s catches, allowing them to sell a fresher product at a greater price. The Eastern plant could potentially produce around 15m3/day - enough to run a small irrigation system in the dry season and support a small ‘cottage industry’ in the wet season.

If this type of sanitation plan was to be introduced, it could bring significant resource development for the village of Andavadoaka.