Methanation and drinking water supply projects in the village of Giteranyi, Burundi

The methanisation project will produce biogas and organic manure from organic household waste and animal excrement. Two important aspects establish an interesting link with the drinking water supply project in the village of Giteranyi.

On the one hand, in a rural environment such as the village of Giteranyi, where environmental sanitation leaves much to be desired, this project will make it possible to collect and process the many types of waste likely to contribute to environmental pollution, including groundwater. Indeed, household and animal waste is spread anywhere and anyhow in the village. Moreover, some households or public facilities do not even have latrines, and human excreta are scattered here and there in the vicinity of houses, schools or markets. There is no waste collection and recycling programme. This waste is therefore likely to be carried away by seepage water and thus contaminate the groundwater table that is exploited for the village water supply. This potential source of contamination is all the more worrisome since the dwellings or public infrastructures are located in the recharge area of the aquifer that will be exploited, in other words, upstream of the valley where the groundwater exploitation boreholes will be built.

In addition, the methanation project will produce biogas, an alternative and affordable source of energy for rural households in Giteranyi. Indeed, to date, the source of energy for households in the village of Giteranyi is mainly wood. However, with the galloping demography that is characteristic of developing countries, the use of wood as an energy source is leading to deforestation, which is now reaching worrying levels. Deforestation favours surface runoff to the detriment of rainwater infiltration. Deforestation hardens the soil surface and forms a layer that is poorly permeable to infiltration water. Thus, by increasing surface runoff, deforestation greatly reduces the replenishment of groundwater reserves through infiltration, which in the long run can lead to the depletion of exploited groundwater bodies. The use of biogas instead of firewood is therefore proving to be an effective means of combating deforestation and thus maintaining an adequate rate of renewal of groundwater reserves.