Vietnam. Ha Tay province. Lai Xa. An old woman, wearing the traditional vietnamese hat and her body covered with plastic sheetings as a rain protection, walks on the road. No floods on the main road after a heavy rain. Through the construction of a main drainage and the building of sewerage as a combined system, collecting both rainwater and domestic waste water, the implementation of a flexible decentralized community sanitation project in a context of low infrastructure investment and in a peri-urban case study, such as Lai Xa, is a major sucesss. It offers importants benefits as an alternative to centralized systems, namely in terms of health improvements and by the possibility of dealing with wastewater locally, through households and decentralized municipal structures. Lai Xa is a typical hamlet (village) of the Red River delta region and is part of the Kim Chung commune located 15 km west of Hanoi. The peri-urban location is under increasing pressure of urbanization. 05.04.09 © 2009 Didier Ruef