“Lead pipes have long delivered drinking water to older municipalities in the Northeast and Midwest, along with the risk that they could leach lead. The water-contamination debacle in Flint, Mich., one of the nation’s worst public health disasters, highlighted the threat after thousands of children were exposed. Now, half a dozen years later, President Biden has put a sweeping remedy at the center of his plans to rebuild the nation’s infrastructure…in minority and low-income communities,” The Post’s Dino Grandoni reports.