The wells, known as Class VI wells, are used to store carbon dioxide captured from industrial facilities or directly from the air. Colorado joins Arizona, Texas, Louisiana, West Virginia, Wyoming and North Dakota in overseeing this type of permitting rather than relying on the EPA’s federal program.

“With the growing interest in this technology, we wanted to hopefully provide a faster regulatory and permitting framework than waiting for the federal EPA program,” said John Brown, a public information officer for the Colorado Energy and Carbon Management Commission, the state agency overseeing the wells.

Two projects are approved or under review in Colorado. Front Range Energy’s ethanol plant outside Windsor recently received approval to begin injecting carbon dioxide underground. Sterling Ethanol and Yuma Ethanol plan to store emissions through Carbon America’s Denova project, which is under state review. Together, the projects could capture as much as 480,000 metric tons of carbon dioxide a year, according to a commission presentation—roughly equivalent to the annual electricity emissions of nearly 100,000 homes.

Colorado’s climate strategy includes carbon storage as part of its goal of reaching net-zero emissions by 2050. State rules require wells to be at least 2,000 feet from homes and businesses, and operators must submit analyses of cumulative health and environmental impacts before construction. Carbon dioxide pipelines are regulated separately; the commission does not approve or regulate those pipelines, Brown said.

The technology also faces concerns about safety and whether it delivers enough climate benefit. In 2020, a carbon dioxide pipeline rupture in Mississippi sent at least 45 people to the hospital. A federal investigation found that the operator did not alert emergency responders. Mark Seeley, the commission’s geothermal and carbon storage supervisor, said Colorado’s rules are more stringent than federal requirements.

Anika Juhn, an energy data analyst with the Institute for Energy Economics and Financial Analysis, said carbon capture remains a developing technology and that residents may not always be aware of risks near proposed facilities. She has also questioned whether the energy and water needed to operate some projects could offset their climate benefits. A 2020 study led by University of California, Berkeley researchers found that widespread carbon capture to meet global climate targets could nearly double global water use.

Environmental advocates say storing emissions could also allow polluting facilities to keep operating. “We have a lot of concerns that it’s a false solution that could lead to the extending of polluting facilities in communities,” said Ean Tafoya, Colorado director of GreenLatinos.

Federal tax credits provide companies $85 to $180 for each ton of carbon dioxide stored, and Brown estimated that fewer than a dozen companies may pursue new projects in Colorado over the next year or two. The state commission is studying where underground storage capacity is greatest, including areas along the Front Range, in northwestern Colorado and parts of the Western Slope.