EXTRA: Why don’t we know where all the lead pipes are?

In April, President Joe Biden announced an infrastructure plan that includes removing and replacing all of America's lead drinking water pipes. It's an ambitious plan that would help millions of American children, and it was met with a lot of praise. But we couldn't help but wonder if this plan sounded too easy. Because as we've seen on a much smaller scale, sometimes it's really hard to know where all the lead pipes are. Host: Sara Ganim. Guests: Erik Olsen, Alex Stubblefield.