There's probably a place for desalted seawater in meeting the nation's future water needs, but research is needed to reduce the costs and impact on the environment, the National Research Council said in a report released Thursday.
"Uncertainties about desalination's environmental impacts are currently a significant barrier to its wider use, and research on these effects — and ways to lessen them — should be the top priority," said Amy Zander, chair of the committee that wrote the report and a professor at Clarkson University.
The NRC said that improving technology is making it more realistic to consider desalination of water.
"Finding ways to lower costs should also be an objective. A coordinated research effort dedicated to these goals could make desalination a more practical option for some communities facing water shortages," Zander said in a statement.
Some 97 percent of the water on Earth — seawater and brackish groundwater — is too salty for drinking or irrigation.
There is currently no overall coordination of federal research on desalination, and the analysis recommended that the government work be coordinated by the White House Office of Science and Technology Policy.
Most desalination research has been funded by private business, the report notes.
The committee also noted that while desalination generates less than 0.4 percent of the water used in the U.S., the nation's desalination capacity grew 40 percent between 2000 and 2005 and that desalination plants now exist in every state.
"Most use a method called reverse osmosis, which pushes water through a membrane to separate out most of the salts." the panel noted in its statement.
Environmental concerns include:
- threats to fish and other aquatic animals from water intakes;
- high energy use in the salt-removal process;
- disposal of the salty sludge left over from the process.
The study was sponsored by the U.S. Bureau of Reclamation and the U.S. Environmental Protection Agency.
The National Research Council is an arm of the National Academy of Sciences, an independent organization chartered by Congress to advise the government on scientific matters.