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Title:Desalinating seawater sounds easy, but there are cheaper and more sustainable ways to meet people's water needs
Date:9/22/2022 9:43:32 AM
Summary:

Coastal urban centers around the world are urgently looking for new, sustainable water sources as their local supplies become less reliable. In the U.S., the issue is especially pressing in California, which is coping with a record-setting, multidecadal drought. California Gov. Gavin Newsom recently released a US$8 billion plan for coping with a shrinking water supply. Along with water conservation, storage and recycling, it includes desalination of more seawater.

Ocean desalination, which turns salt water into fresh, clean water, has an intuitive appeal as a water supply strategy for coastal cities. The raw supply of salt water is virtually unlimited and reliable.

Ocean desalination is already a major water source in Israel and the United Arab Emirates. Cities in the Middle East, Australia, Mediterranean Europe, the U.S. Southwest and Australia also rely on it. There are more than 20 ocean desalination plants operating in California, plus a few in Florida. Many more plants across the U.S. remove salt from brackish (salty) water sources such as groundwater inland, especially in Texas.

Nonetheless, current evidence shows that even in coastal cities, ocean desalination may not be the best or even among the best options to address water shortfalls. Here are the main issues that communities evaluating this option should consider.

Killing aquatic life

Scalable technologies for removing salt from water have improved steadily over the past few decades. This is especially true for treating brackish groundwater, which is less salty than seawater.

But desalination still can have major environmental impacts. Fish can be killed when they are trapped against screens that protect desalination plants' intake valves, and small organisms such as bacteria and plankton can be sucked into the plants and killed when they pass through the treatment system. In May 2022, the California Coastal Commission unanimously rejected a proposed $1.4...

Organization:PHYS.ORG - Technology
Date Added:9/23/2022 6:38:55 AM
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