ABSTRACT
The WHO programs started out concentrating on the urban areas first. The urban areas have been under continuous pressure to catch up with water supply needs because of rapid growth. In the larger urban areas water supply and treatment facilities are very similar to those in developed countries. This is often a problem because, due to a lack of trained maintenance people and operators, it was difficult to provide the chemicals needed for treatment and to keep the sophisticated plants in operation. In the rural areas it is possible to make large improvements with simple methods. There is a center at Delft, The Netherlands, where information is gathered on simple water supply and treatment techniques found useful in developing countries. Cultural differences must be considered, as well as the fact that human excreta may be used for fertilizer. More complex wastewater treatment systems often stand as "monuments of disuse," because of a lack of adequately trained technical and operating personnel.
