Water 4.0The little known story of the systems that bring us our drinking water, how they were developed, the problems they are facing, and how they will be reinvented Turn on the faucet, and water pours out. Pull out the drain plug, and the dirty water disappears. Most of us give little thought to the hidden systems that bring us water and take it away when were done with it. But these underappreciated marvels of engineering face an array of challenges that