Sea water desalination in the Mediterranean assessment and guidelines

United Nations Environment Programme (2003)

The need for desalting seawater is becoming more and more pressing in many parts of the world. During the period from 1950 to 1990 the worldwide consumption of water was tripled, while the population grew by 2.3 billion people. In the Mediterranean, the present and future water needs are really increasing. It is estimated that by the year 2010 water demands will increase by 32% at least for the southern and eastern countries. There is no doubt that the above water needs can be covered and satisfied if only non-conventional resources of water are utilized, like water- recycling and desalination. Desalination has for a long time been a major source of water in parts of the Mediterranean. Desalination plants exist in places that have hot climates, relatively low and unpredictable rainfall and where conventional water resources are unable to meet peak tourist demands. Seawater desalination by Mediterranean countries is a steadily growing industry. This practically unlimited resource of water requires energy consumption and results to environmental impacts. These impacts are generated mainly from the concentrate (brine) produced during the desalination, but also from the discharges of chemicals used in the desalination processes. Although the number of scientific publications dealing with the issue is limited, the discharge of concentrate into the sea requires particular attention and scientific assessment of possible impacts on the marine environment. There is no doubt that Mediterranean countries, which use desalination to cover their freshwater needs, should apply appropriate guidelines or procedures for the disposal of brine according to the LBS and Dumping Protocol. As a result, this document was prepared to offer a basis for discussion aiming at identifying a common management approach in line with the Barcelona Convention and its Protocols.