Named for the friend of a French king, Louisiana’s Lake Maurepas is a large tidal estuary at the confluence of four rivers, a geographic lace-hole in the boot-shaped state. Today, it’s known mainly for shrimping. But if a company called Air Products gets its way, the 93-square-mile expanse will also be the setting for a mile-deep pool of carbon dioxide, a project aided by the Biden administration’s big bet on carbon capture technology.

Many Louisiana residents are big supporters of the oil and gas industry, but they worry about the idea of using relatively untested technology to pump 5 million metric tons a year of carbon dioxide — more than what 1 million cars emit in a year — into a cavern underneath the smooth waters of their lake. Kim Landry Coates, a council member of neighboring Tangipahoa Parish, said many of her constituents are concerned about burying the colorless, odorless gas that, in high concentrations, can choke people unconscious.