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Impacts of Relying on Desalination for Water

Desalination, also known as desalinization, is a process by which salts and minerals are removed from water to provide clean drinking water. According to the Sydney Coastal Councils Group, Inc., a number of technologies have been developed for desalination, such as reverse osmosis, electrodialysis, distillation and vacuum freezing. Desalination provides a valuable source of drinking water in areas where demand is high, and natural reserves are being depleted and/or becoming unreliable. However, desalination can have adverse effects on the environment.

Construction of a Desalination Plant
- Desalination plants are often large structures and will have an impact on the local ecosystems on which they are built. For instance, the Sydney Coastal Councils Group Inc., provides an example of the impact of constructing a desalination plant. They anticipate significant impacts on the delicate local ecosystem, with threats to heritage listed sand dunes, sensitive wetlands and protected marine and intertidal areas. Moreover, due to the requirement of being located on the coast, large areas of coastline will be lost due to desalination plants. Therefore, a reliance on desalination for water will require more of these plants to be built, impacting upon a gradually increasing area.
Harmful Discharges
- Discharges from sea water desalination plants can have a detrimental impact on coastal water quality. For instance, the process of reverse osmosis results in a highly saline brine being released into the sea, which usually is of a higher temperature than the seawater. Due to the density of this brine, it sinks and is damaging to benthic communities, located on the ocean floor, as explained by marine environmental scientist Sabine Lattemann. Furthermore, discharges from distillation plants often contain harmful chemicals left from the pre-treatment process, such as chlorine, in addition to cleaning agents and some heavy metals from corrosion. Thus, as Sabine Lattemann argues, the discharges from desalination processes impact upon the quality of the resource on which it depends. However, methods such as diluting the saline brine can be implemented to help reduce the impact of these discharges.
Ocean Biodiversity
- The discharges released from desalination plants are harmful to ocean biodiversity, due to the effect on the habitat of many species. Furthermore, according to the Scientific American, seawater desalination plants can inadvertently kill millions of plankton, fish eggs, larvae and many other organisms that constitute the base layer of the marine food chain, due to the way in which the plants "vacuum up" sea water.
Climate Change
- According to the Australian Government, desalination processes require vast amounts of energy provided by fossil fuels, which release greenhouse gases when burnt, contributing to global warming. Relying on desalination for water will increase greenhouse gas emissions due to higher energy requirements, potentially exacerbating global warming. Thus, as explained by the Scientific American, global warming, which has been attributed towards increasing droughts across the world, resulting in an increased need for desalination for water, will also potentially be exacerbated by desalination plants.

Nature