Ten miles south of Tel Aviv, I stand on a catwalk over two concrete reservoirs the size of football fields and watch water pour into them from a massive pipe emerging from the sand. The pipe is so large I could walk through it standing upright, were it not full of Mediterranean seawater pumped from an intake a mile offshore. “Now, that’s a pump!” Edo Bar-Zeev shouts to me over the din of the motors, grinning with undisguised awe at the scene before us. The reservoirs beneath us contain several feet of sand through which the seawater filters before making its way to a vast metal hangar, where it is transformed into enough drinking water to supply 1.5 million people. We are standing above the new Sorek desalination plant, the largest reverse-osmosis desal facility in the world, and we are staring at Israel’s salvation. Just a few years ago, in the depths of its worst drought in at least 900 years, Israel was running out of water. Now it has a surplus. That remarkable turnaround was accomplished through national campaigns to conserve and reuse Israel’s meager water resources, but the biggest impact came from a new wave of desalination plants. Bar-Zeev, who recently joined Israel’s Zuckerberg Institute for Water Research after completing his postdoc work at Yale University, is an expert on biofouling, which has always been an Achilles’ heel of desalination and one of the reasons it has been considered a last resort. Desal works by pushing saltwater into membranes containing microscopic pores. The water gets through, while the larger salt molecules are left behind. Microorganisms in seawater quickly colonize the membranes and block the pores, and controlling them requires periodic costly and chemical-intensive cleaning. But Bar-Zeev and colleagues developed a chemical-free system using porous lava stone to capture the microorganisms before they reach the membranes. It’s just one of many breakthroughs in membrane technology that have made desalination much more efficient. Israel now gets 55 percent of its domestic water from desalination, and that has helped to turn one of the world’s driest countries into the unlikeliest of … Continue reading How a new source of water is helping reduce conflict in the Middle East