It’s a situation reminiscent of the old line: “Water, water, everywhere, nor any drop to drink.” A new report from our partner, The New York Times, says that might be a fair description of some U.S. water supplies. Since 2004, the water provided to more than 49 million Americans has contained illegal concentrations of chemicals like arsenic or uranium, as well as dangerous bacteria often found in sewage.

Charles Duhigg is a New York Times business reporter, and tells us what to be worried about, and why violations weren’t caught sooner.