Defunct oil wells are a national problem. Finding them is the first step

Dan Arthur, the president and chief engineer of ALL Consulting, stands beside a defunct oil well in the Tallgrass Prairie Preserve in Oklahoma on March 20, 2024. The well has not been used for years — there

There could be about a million 'orphan' oil and gas wells across the U.S. As they age, they can leak greenhouse gases or unhealthy chemicals.

(Image credit: September Dawn Bottoms for NPR)