Desalination: Tapping the Ocean and Brackish Aquifers
Desalination offers a drought-proof supply but at high energy cost and with brine-disposal challenges — a complement to, not a replacement for, reuse.
Desalination removes salt from seawater or brackish groundwater to produce fresh water, usually via reverse osmosis. Because the ocean is effectively unlimited, it offers a supply that does not depend on rain or snowpack.
The trade-offs are energy and environmental impact. Desalination is among the most energy-intensive ways to produce water, and disposing of the concentrated brine byproduct requires care to protect marine life. The Carlsbad plant near San Diego is the largest in the country.
Many planners view desalination as one tool in a portfolio — most cost-effective for coastal cities with few alternatives — while inland communities generally find water reuse far cheaper per gallon.
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