Guests: John Heidelberg Assistant Investigator The Institute for Genomic Research Rockville, Maryland By one estimate more than a billion of the world's people do not have access to clean drinking water, and three billion live without water for sanitation. At the same time, aquifers around the world are being overdrawn, and many of the world's major rivers run dry for large parts of the year. Will water become a commodity more valuable than oil? How will we meet the water needs of an increasing population? Join us in this hour for a look at the world's water supply. Plus, the latest in the fight against a major water borne disease—cholera.