Today, desalination plants are used to convert sea water to drinking water on ships and in many arid regions of the world, and to treat water in other areas that is fouled by natural and unnatural contaminants.

Why is desalination a good idea?

Benefits of Seawater Desalination:

Provides people with potable water (clean & fresh drinking water). Provides water to the agricultural industry. Water quality is safe (not dangerous or hazardous to any living thing). ... Unlimited ocean water as source.

Why is desalination bad?

Desalination has the potential to increase fossil fuel dependence, increase greenhouse gas emissions, and exacerbate climate change if renewable energy sources are not used for freshwater production. Desalination surface water intakes are a huge threat to marine life.