The pros of desalination are increased clean drinking water and the preservation of freshwater supplies, which are limited. The cons of desalination are the high energy costs of the process, the relatively high capital cost of desalination plants, and the potential environmental damage of the brine created during desalination.
Desalination is the process of removing salt and other substances from salt or brackish water to create high-quality drinkable water . Although the surface of the Earth is more than 70 percent water-covered, more than 96 percent of this water is saline, or salt water. Reverse osmosis is a proven method to draw clean water, drinkable or usable for growing crops, from salt water.
Although desalination is considered expensive compared to groundwater or rain water, during periods of drought, the costs are considered more reasonable. As of 2014, the energy required for desalination is about 2 kilowatt hours per cubic meter of water, and desalination plants meet this energy need with fossil fuel. Desalination plants also produce pollution in the form of brine, concentrated waste that has up to twice as much salt content as sea water and may contain chemicals such as chlorine and the anti-scaling and anti-caking agents used in the process. Experts argue, however, that desalination plants may be less damaging on the environment than long pipelines or large-scale dams.