The improvement of ventilated improved pit latrine sanitation systems.

Abstract

Burkina Faso is a country in the Sahel of West Africa struggling, like many developing nations, with the problem of providing adequate sanitation to its poorest regions. Inadequate sanitation is responsible for many health problems and results in much lost potential, thus exacerbating the country's economic and social problems. In response to this need, sanitation workers developed the ventilated improved pit (VIP) latrine in the mid 1980's. Since its design, thousands of VIP latrines have been installed throughout Africa. However, reports of poor operation resulting in a return of the odour and fly problems of older latrines have been received. This project investigated the ventilation of the VIP latrine and attempted to find a way to improve the ventilation rate. Three accessories, a venturi, a slotted fitting and a diverging fitting placed at the outlet of the ventpipe, were considered as possible methods of achieving this end. The fittings were analyzed theoretically and tested in the laboratory and in the field. The results of the tests showed that the divergent fitting was no more effective in inducing up-flow than the open pipe. Given that the slotted fitting is significantly more expensive than the venturi and that the wind in Burkina Faso is such that the slotted fitting would be effective for only a small portion of the year, it was concluded that the most appropriate accessory is the venturi. The field portion of this project was conducted in Ouagadougou, Burkina Faso with the aid of Centre regional pour l'eau potable et l'assainissement a faible cout (CREPA). (Abstract shortened by UMI.)