America's decaying oil and gas wells will cost billions to clean up

Scattered throughout the U.S. are millions of orphaned oil and gas wells. They're a major source of methane emissions and can leak contaminants into the groundwater. But it's hard to locate these wells, as many were drilled before modern mapping and recordkeeping technologies became widespread. It's going to cost billions to clean them up, but for the first time there's major federal funding devoted to doing just that.