“The shortage of fresh water supplies constitutes a severe problem in several regions surrounding the Mediterranean Sea and particularly in the arid and semi-arid areas of the South Mediterranean and Middle East Regions. The problems encountered in trying to achieve economic sanitation in the Mediterranean region lead to the conclusion that the success depends to a large extent on the ability to develop effective, rational and affordable strategies for sewage treatment. The partial or complete closure of water cycle is an essential part of sustainable water-resource management and wastewater treatment and re-use should be considered within the wider context of sustainable development.”