Wastewater re-use and groundwater quality: introduction.

In many parts of the world regional water resources and future water supply are at risk as a result of climate change and population increase. Innovative measures are necessary to find socio-economically acceptable solutions to combat the existing scarcity of water. Re-use of (pre-)treated wastewater, especially in agriculture, could considerably contribute to conservation of regional water resources, recycling of nutrients and prevention of surface water pollution. However, water quality guidelines for wastewater irrigation are very strict in order to prevent health risks from pathogenic organisms and guarantee crop quality. An integrated approach is needed in the water chain; groundwater resources, wastewater production, wastewater (pre-) treatment, wastewater re-use, to find optimal solutions with respect to food security, cost-effectiveness, environmental load and health risks. In general, implementation of a new concept is difficult as a result of institutional complexity and resistance. Local institutions and engineers need to further develop and adapt the treatment systems to the local climate and cultural conditions. There is a need for a course to be set-up and information to be made available to educate and train students in this complex field.