Last month, the agriculture conglomerate Archer Daniels Midland announced it was temporarily shutting down a carbon storage site in Illinois after discovering a leak underground. Now environmentalists are pressuring the Environmental Protection Agency to hold up the permitting of new projects until more data is gathered.

“There haven’t been a lot of long term (carbon) storage projects in the world,” said Virginia Palacios, executive director of the non-profit Commission Shift. “This is material that’s supposed to be underground for thousands of years.”