Solving the world's water problems is proving to be one of the greatest investment opportunities of our time. Already, world water supplies are inadequate to meet demand, and the problem is going to get much worse in the years ahead. The World Bank estimates that 1.1 billion people lack access to safe drinking water and about 50 percent of the world's hospital beds are populated by people who have contracted water-borne diseases. If present consumption rates continue, in 25 years the world will...