JOCHEN BUNDSCHUH completed his PhD on numerical modelling of heat transport in aquifers in Tubingen in 1990. For over 14 years he is working in international academic and technical co-operation in different fields of sustainable use of groundwater systems and connected disciplines, including the water-related economic, social, health, and political aspects. The last 12 years he spent in different Latin-American countries, where his main tasks comprised capacity building for institutional strengthening and human resources development applied research, and project management. The countries comprise: Paraguay, Argentina, Brazil, Uruguay, Brazil, Mexico, Bolivia, Costa Rica, Honduras, Guatemala, Panama, Pakistan, India, Bangladesh, middle East, Tunisia and South Africa. From 1993 to 99 he served as expert of the German Agency of Technical Cooperation (GTZ) and as long-term professor for the DAAD (German Academic Exchange Service) in Argentine to install a centre for water and environment offering training, consulting and research. Currently (since 2001) he is integrated expert of the GTZ/CIM programme for technical cooperation between Germany and costa Rica and deals with the sustainable use of surface and groundwater resources for power generation. This mission comprises to develop and apply capacity building programmes, research, and to identify and formulate project proposals. Additionally to these principal activities, he is involved in many consultancies, capacity building programmes and projects in Latin- America, but also in Africa and Asia, which are comprising-in between others- research of groundwater contamination by arsenic originating from gelogenic resources.