Designing a Sustainable System for Water Supply and Sanitation in Rural Peru

Sammanfattning: Given the tremendous importance of water supply and sanitation (WSS) on health and welfare, the purpose of this thesis was to suggest a design of a sustainable WSS system for a rural village in the sub-Andean Amazon of Northern Peru. WSS planning and intervention in the developing world have traditionally been characterized by large failures, and to understand the related problems, this work was initiated with a literature review on the topic. The review resulted in the development of a planning support, containing eight stages ranging from project identification to project realization. Within this thesis, the first four stages were implemented, including an in-field WSS situation assessment and a screening of suitable technical options. The in-field assessment contained a general fact collection, an inventory where about a fifth of the households in the village was visited and interviewed, and a water quality analysis. An analysis of the assessment findings resulted in the identification of the WSS components requiring intervention. Thereafter followed a screening of suitable technologies, and based on the results from the analysis, a selection of interesting options was done. Selected options were reviewed and evaluated according to a set of sustainability criteria. A majority of the households in the village had standpipes on their premises, delivering untreated water from an unprotected creek outside the village. Apart from surface water, rainwater and water from an open spring were also used in the village. The water analysis revealed that surface water contained elevated levels of bacteria, whereas the spring water was clean. Contaminated water remained contaminated after household treatment (boiling), indicative of poor handling. Water treatment with solar disinfection (SODIS) proved to be effective. The sanitary situation was not satisfactory; almost all households had unimproved pit latrines that could not ensure a hygienic separation of excreta, and open defecation was also practiced. Greywater, resulting from showering and cloth-washing under the standpipe, was at best diverted away from the premises by small drains, but often not managed at all. Stormwater created unhygienic conditions on both private premises and in communal areas during the rainy season; the management situation was similar to that of greywater. Solid waste was not officially managed and even though many of the households had designated a collection site, waste was commonly seen all over the premises. The selected technologies were mainly inexpensive such that could be constructed, operated and managed by the community itself. From the assessment it also became clear that the WSS situation could be considerably improved by behavior change. Following the developed planning support; with the finalization of this thesis, the next step would be to present the results from the screening and evaluation of technologies to the villagers, for them to decide which options to proceed with.