After the preliminary evaluation, the project team defined 2 areas of intervention. The first area, San Juan de Lurigancho, is the largest and most populated district in Lima; it is a peri-urban area with an arid climate. Approximately 50% of the 731739 inhabitants of this settlement live on the steep hillsides common to the region; many homes are inaccessible by road and therefore to the trucks that distribute water. In addition, the steep slopes and rocky soil make it difficult to construct adequate latrines. The second area of intervention was the settlement Manuel Cardozo davila in the city of Iquitos in the Amazonian jungle; this settlement is located in a zone with one of the highest growth rates in the country