First of all, the saltwater is taken from the sea and passed through the pre-treatment filter which at this stage big impurities are removed. Besides, the filter backwash is piped into the sea. Subsequently, the water is forced through membrane at high pressure that all impurities even salt are gotten stuck within the filter. It should be noted that in this step the seawater concentrate is returned into the sea. After that, some substances such as lime, chlorine and fluoride are added to the water to make it appropriate for drinking. Afterwards, the water is supplied and finally it is piped into the integrated water supply system to be used by people.To sum up, the water of sea should be passed through some filters and treated by some materials to be healthy for people.