Desalination use growing despite energy, environmental issues

Desalination seems a perfect solution to water shortages. Take the salt out of ocean water and turn it into drinking water. 300 million people today rely on desal water. However, there are serious issues. First off, desalination requires a lot of electricity and in too many areas today, like the Middle East, that power comes from fossil fuels, which contribute to global warming. Second, bringing ocean water into the plant can kill fish, larvae, and plankton plus dumping the salty brine back into the ocean will have deleterious effects. Third, it’s expensive. The Carlsbad desal plant near San Diego treats 50 millions gallons a day. However the cost is double that of their primary source of water, the Colorado River.

One promising approach is to use brackish water, which is much easier to clean because it has much less solids in it and doesn’t require being near an ocean, so it’s cheaper than ocean water desalination.

De-sal proponents acknowledge the industry must confront and solve some serious environmental issues if it is to continue to grow. Desalination requires vast amounts of energy, which in some places is currently provided by fossil fuels. Kiparsky warns of a feedback loop where more de-sal is needed as the planet warms, which leads to more greenhouse gas emissions. In addition, there are serious concerns…