Abstract
The Arabian Gulf coast of Saudi Arabia contains a large number of existing desalination facilities of which many use the seawater reverse (SWRO) osmosis process. Many SWRO facilities have had historical operational problems with membrane biofouling. Subsurface intake system feasibility was assessed generally for the coastline of Saudi Arabia and a site-specific investigation was conducted at Ras Abu Ali Island. It was found that the common occurrence of sabkhas along the shoreline of Saudi Arabia causes the use of conventional vertical wells to be risky due to migration of hypersaline water into them. All well types do not appear to be feasible based on the shoreline and nearshore geological conditions. Beach galleries were assessed and are also subject to failure caused by migration of hypersaline water and possible burial by dune sands moving eastward from the desert into the Arabian Gulf. Seabed gallery intake systems were found to be the most technically feasible subsurface intake type which could provide high capacity SWRO facilities with feed water. However, the low slope from the beach seaward and the tide range necessitate that seabed galleries would have to be constructed over 500 m seaward of the beach. This distance would make the construction complex and would require future design and construction innovations. Perhaps the seabed gallery cells could be constructed adjacent to an artificial fill peninsula that would allow easier access and less expensive construction.