Desalination: What is it and how does it work? Desalination refers to any of several processes that remove dissolved salts and impurities from a water source such as seawater and turn it into fresh, drinking quality water. The greatest benefit of desalination is that it enables us to deliver water all year round, even in times of drought. Reverse Osmosis The Adelaide Desalination Plant uses a technology called Reverse Osmosis to desalinate seawater from the Gulf of St Vincent. Reverse osmosis is the most commonly used process to desalinate water and involves pushing seawater through super-fine membranes at extremely high pressure. It can remove up to 99% of the dissolved salts and inorganic matter. Used around the world, reverse osmosis provides the finest level of filtration available and delivers clean, healthy water. Saline Concentrate While reverse osmosis produces fresh water, the process also creates water with a higher concentration of salts. This saline concentrate is dispersed about 1km offshore through specially designed diffusers – where it is very quickly and efficiently mixed with the neighbouring seawater. The proportion of saline concentrate dispersed is tiny compared to the large volume of seawater in the receiving waters of the Gulf, so the concentration of salt in the Gulf does not change. Salinity levels in the surrounding seawater are regularly monitored to ensure there are no environmental impacts on the marine environment.