Bangladesh has made a significant effort to supply improved sanitation facilities in rural areas. As the best known option, the pit latrine was the most favorite technology. Yet, as Bangladesh is a country of flooding and high groundwater table, pit latrines not only flush out and cause pollution, they also become inaccessible during floods, and remain filled with silt after the floods. Every year floods destroy many sanitation facilities and force people to resort to open defecation, despite the capitalintensive investment. UDDTs were evaluated on their suitability for flood-prone areas and...