Seawater intake facilities

V.M. Venkatesh Mannar, Design of Seawater Intake Facilities for Solar Salt Plants, Proceedings, Sixth International Symposium on Salt, vol. II (1983), p. 289. 

The seawater intake facilities are among the key components of every SWRO plant. Adequate and consistent flow and quality of source water over the entire useful life of the plant must be assured. The source water collection system for SWRO desalination plants could be an open-ocean intake or subsurface (beach well) intakes. 

The largest SWRO plant in North America, which obtains source water fiom beach wells, is the 15,000-m /day water supply facility for the Pemex Salina Cruz refinery in Mexico. This plant also has the largest existing seawater intake wells—three Raimey-type horizontal collectors with capacities of 15,000 m /day each. Key considerations for the selection of the type of intake most suitable for the site-specific conditions of a given SWRO plant and guidelines for the development of subsurface intakes for seawater desalination plants are discussed elsewhere (AWWA, 2007 Wright and Missimer, 1997 Voutchkov, 2004a). 

Seawater RO desalination plants typically consist of the following key components intake pretreatment system filter effluent transfer pumps high-pressure pumps, piping, and RO membrane system energy recovery system and permeate conditioning (posttieatment) facilities. 

As previously mentioned, the key SWRO project construction expenditures are associated with building the plant intake, the pretreatment system, procurement and installation of the plant pumps and piping, the SWRO membranes and pressure vessels, the energy recovery system, the water posttreatment facilities, and the concentrate disposal system. It is difficult to compare the investment and construction costs of existing desalination projects because projects may differ significantiy in one or more of the cost-related parameters listed above. Based on previous experience, however, it can be estimated, for example, that the seawater pretreatment costs are in the range of 6-8 US cents/m and the costs of water conditioning and boron and chloride removal are between 4 and 8 US cents/m. ... 

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