Process FAQs

What is seawater desalination?

It is a process that turns ocean water into fresh drinking water by removing salt and impurities. The process involves either reverse osmosis membrane or thermal distillation (evaporation) technologies. Poseidon's projects including the Carlsbad Desalination Project plant use reverse osmosis technology.

How does the reverse osmosis process work?

Water is pushed under high pressure through a semi-permeable membrane to separate salts and other solids from the water molecules. The membrane acts like a microscopic strainer that allows only the water molecules to pass thorough. The technology was developed over 30 years ago.

Can the salt and minerals extracted be used?

Unfortunately not. The amount of salt generated is too great to be processed at the project site while the amount of mineral is too small to justify the expense of additional processing.

Does weather affect the availability of water for desalination?

No. It is a drought-proof process unaffected by rainfall or other weather conditions. Part of the testing done at the pilot project determined that even in the most difficult operating conditions, the process works well.

Where else has desalination been successful?

Similar facilities have been operating worldwide for several decades. Desalination is used in arid, coastal regions throughout the world. There are more than 21,000 desalination facilities operating worldwide.

If it's so great, why aren't there more plants?

Until recently, cost has been the limiting factor. Dramatic technological improvements have made desalination much more cost-effective. For example, the reverse osmosis membranes used today last longer, use significantly less energy and cost much less than they did just a decade ago. Co-locating the plants with existing coastal power plants and using their intake and outfall facilities also results in large cost savings.

What is the quality of the water produced?

The desalinated water will meet or exceed all local, state and federal standards for drinking water. Desalination produces some of the highest quality drinking water. The same reverse osmosis process is used by bottling plants to produce premium drinking water from a number of sources.