Carbon sequestration wells will swell from a few to more than 40

For all the talk of carbon dioxide sequestration, not many sites today are injecting CO₂ underground for permanent storage. That’s likely to change in 2024 as the US Environmental Protection Agency and other government bodies around the world approve a raft of permits for project developers eager to start storing CO₂.

The EPA regulates CO₂ sequestration as part of its authority over underground waste disposal under the Safe Drinking Water Act of 1974. The approval needed to store the greenhouse gas is called a Class VI well permit. Classes I–V are for other types of gas and liquid waste.

The agriculture giant ADM has two Class VI permits, the only ones issued by the EPA as of Jan. 12. Both are for its complex in Decatur, Illinois, where it injects CO₂ generated during ethanol production. The first was a demonstration project that buried about 1 million metric tons (t) of CO₂ total between 2011 and 2014. The other is still active and can sequester about 1 million t per year.

If the EPA keeps to its current timeline estimates, its count will jump this year to 38 permitted wells at sites spread across the US Midwest, South, and West Coast. Though not all wells will begin injection right away, several are revving their engines at the starting line.

One example is a site owned by the ethanol maker Marquis Energy. The firm’s plant in Hennepin, Illinois, sits over a sandstone formation capable of sequestering a total of more than 100 million t of CO₂, according to Jennifer Aurandt-Pilgrim, Marquis’s vice president of R&D.

“Next year at this time, we’ll be sequestering 1.2 million t of CO₂ under the ground on our property,” she said at a cleaning product industry meeting in September. “For every kilogram of ethanol I sell you, you’re taking 0.3 kg of CO₂ out of the atmosphere.”

Wyoming and North Dakota have permission from the EPA to handle their own Class VI permits, a privilege known as primacy. Wyoming issued its first three Class VI permits in December. Lily Barkau, who leads the Class VI well permit process for the state’s Department of Environmental Quality, says her office expects to issue five more in 2024. Wyoming also denied a permit in November.

As of October, North Dakota had approved three corporate projects for a total of eight wells in the state. Three more companies have applications with North Dakota in progress, and all are likely to get decisions in 2024. Louisiana won primacy on Jan. 5 of this year, and Arizona, West Virginia, and Texas have also applied to the EPA for Class VI primacy.

Europe is the other big region for CO₂ sequestration projects. According to a database maintained by the nonprofit Clean Air Task Force, the European Union has 3 active sequestration sites now, 3 under construction, and 97 more in various stages of development.

Climate change advocates emphasize that CO₂ injection wells are far from a stand-alone solution to climate change. In a briefing ahead of the recent 28th Conference of the Parties to the United Nations Framework Convention on Climate Change (COP28), Mark Hertsgaard, executive director of the media education nonprofit Covering Climate Now, said, “As we talk about carbon capture and storage and carbon dioxide removal, there is no substitute to the first, second, and third order of business—which is to stop the emissions.”