The Desalination Situation

Rapid growth is putting increasing pressure on water supplies in coastal communities. Conservation can only do so much, and providing new freshwater supplies is getting more expensive and difficult every day. To help make up the difference, water agencies on both coasts are looking to desalination. Use of desalination technologies is on the increase in the U.S., but it will probably be a long time before what used to be seawater comes out of the average kitchen tap. That’s the consensus among desalination experts, who expect most near-term growth to occur in less energy-intensive applications involving brackish coastal and ground water. But a number of large-scale seawater desalination projects are on the drawing boards, waiting for the day when water demand—and the rising costs of other supply options—make them economically competitive. The article describes the main thermal and membrane technologies for desalination, market prospects in the U.S., ongoing brackish water projects and plan for seawater desalination.