Turn on the faucet in most towns in the United States and you can drink the water with some confidence, if not always absolute security. In much of the world -- India, China, Mexico -- that simple routine of daily life is decidedly more dangerous. For recreation as well as drinking, Americans now enjoy water that is cleaner and safer than it was just twenty years ago. Thanks to state-of-the-art sewage treatment plants and other water pollution control facilities, we have made much progress in cleaning up our lakes, rivers, and coastal waters, reclaiming waterbodies that many Americans thought were permanently contaminated. Major problems remain, but the days are gone -- for good, one hopes -- when pollution on the chemical-laden Cuyahoga was so great that the river caught on fire.