Turning salt water into fresh

The steep environmental cost of desalination

Most of the world’s surface is water, but unfortunately it’s saltiness makes it unsuitable for drinking or agriculture. Yet as global warming aggravates conditions that cause droughts, desalination plants are becoming more prevalent. There are now 13,000 such plants in 120 countries—in the Middle East, North Africa and the Caribbean. The Australian state of Victoria has just approved a $2.5 billion desalination plant but “anti-desal” groups are warning that if it has poor environmental safeguards it could end up like the ones in the Persian Gulf, where the sea runs red. That’s because desal plants have huge underwater intake valves that vacuum up everything nearby: plankton, fish eggs, small plants, larvae and other precious sources of nourishment at the bottom of the food chain. Victoria’s capital, Melbourne, is under severe water use restrictions, owing to drought, but one potential cost from the new plant will be the Orange Bellied Parrot, which feeds on the sea life near the plant.

The Herald Sun

Scientific American