The toxic effects of lead—developmental delays, organ damage, even death—are well-known. But millions of Americans still rely on lead pipes to deliver drinking water. In an attempt to make them safer, researchers at the University of California, Berkeley, are working on a new technology that uses electrical current to rapidly build a protective layer on the insides of the pipes. In early tests they reduced the amount of the toxic metal entering water, but other scientists are skeptical of the method’s potential as a long-term solution.