The fast-rising number of desalination plants worldwide – now almost 16,000, with capacity concentrated in the Middle East and North Africa – quench a growing thirst for freshwater but create a salty dilemma as well – how to deal with all the chemical – laden leftover brine

In a UN – backed study made public on Monday, experts estimate the freshwater output capacity of desalination plants over 95 million cubic meters per day – comparable to 40 percent of the high season flow over Niagara Falls.