Seawater and Brackish Water Treatment: Challenges and Design Considerations / Freshwater is not readily available in The Bahamas, and therefore, the primary source of drinking water is either seawater or brackish groundwater. The treatment of such sources requires careful evaluation and design in order to provide reliable and safe drinking water to consumers and in the meantime minimize the capital and operating costs of such complex treatment systems. Typically, a reverse osmosis membrane system is used to treat salt water, and the challenges encountered by the designer are mainly related to source water withdrawal, pre-treatment prior to reverse osmosis, and post-treatment. For example, beach wells or open intake for seawater withdrawal should be technically and economically evaluated prior to making a decision, and both present infrastructure design challenges. The design of such seawater withdrawal infrastructure directly impacts the costs and operations of the plant. This paper will present the challenges of designing the infrastructure for seawater and brackish groundwater plants in The Bahamas.