Carbon Storage Site That Leaked Set to Restart Injections

Archer-Daniels-Midland’s storage site in Decatur, Illinois, has been on pause since EPA found that brine and CO2 had likely migrated into unauthorized zones.

The Archer-Daniels-Midland logo is seen at the Farm Progress Show in Decatur, Illinois, on Aug. 31, 2015. Seth Perlman/AP

For more than 10 months, the carbon dioxide injection well at Archer-Daniels-Midland's storage site in Illinois has gone unused after testing showed evidence of a potential fluid leak. That pause, however, could be nearing its end.

The agribusiness company — which typically sends 2,000 metric tons of CO2 underground per day at the site in Decatur, Illinois — anticipates resuming injection later this summer.

Advocacy and environmental groups, who pushed unsuccessfully last year for a halt on new permitting of CO2 injection wells, still have a range of questions about what’s happened and changed since ADM detected a CO2 leak last spring. They are also pushing for transparency ahead of the restart of injection and some want to see EPA put forward new regulations.

>> In Other News: CuspAI Targets $100M to Unlock AI’s Potential in Climate Materials

EPA “should absolutely do a new rulemaking for these injection wells to look at and update the standard for the chrome that’s used in the wells, to update the type of monitoring that’s required of these wells,” said Jim Walsh, policy director at the group Food & Water Watch.

ADM, the first company to operate a Class VI storage well permitted by EPA, has been under a magnifying glass since last year after the agency issued a violation notice to it, alleging the company had failed to meet the requirements of its Class VI permit and allowed CO2 and other fluids to move into unauthorized zones. Class VI wells are used to inject CO2 underground for long-term geologic storage.

In mid-September, EPA took the additional step of issuing a proposed enforcement order to ADM, requiring the company to take a series of compliance measures.

ADM said it remains in talks with the agency about the proposed enforcement order.

"We take our commitment to safety and being transparent in reports we submit to the government and in relevant information we share with stakeholders very seriously," ADM spokesperson Jackie Anderson said in a statement.

In an email Monday, EPA said ADM needs to complete steps listed in an April letter before resuming CO2 injections.

EPA spokesperson Molly Vaseliou said the agency does not comment on pending enforcement actions. But she said the agency has received and is reviewing more than 50 public comments on the proposed enforcement order.

"The timing of EPA’s decision on a final order will depend on a number of factors, including the nature of comments received and whether EPA determines any changes to the proposed order are appropriate," Vaseliou said in a statement.

The potential resumption at ADM’s well comes as the Trump administration works to expand the number of states that can issue Class VI permits in lieu of EPA.

Demand to build Class VI wells has skyrocketed since passage of the Inflation Reduction Act in 2022, which boosted the carbon capture incentive known as 45Q. EPA issues Class VI permits in all but four states. EPA awarded the designation, called primacy, to West Virginia in February and subsequently proposed doing so for Arizona and Texas.

EPA has 235 applications for a Class VI now under review. Half of those applications have been submitted over the past 12 months.

ADM is in the process of applying to EPA to add another Class VI injection well.

Jessie Stolark, executive director of the Carbon Capture Coalition, said in a statement that last year’s events don’t undermine the rigor of EPA's Class VI program, noting that "this incident and the operator’s compliance with EPA procedures show that Class VI well monitoring and reporting protocols are working as intended."

Pam Richart, secretary of the Eco-Justice Collaborative, said the failure isn’t just an operator and design failure but also one on the part of EPA.

"It is supposedly the project in all of the country that everybody still points to and says, 'Hey, look at the success there,'" Richart said. "Well, you had some failures. And the way they described it is, lessons learned. Well, we heard about some of those lessons learned, including the fact they think the process worked just as it should have, right."

"But there are all of these failures along the way and what are you going to do to ensure that’s not going to happen again?" Richart said.

Addressing the leak

The company paused CO2 injection in late September at its Decatur facility after tests, mandated by EPA's proposed order, revealed potential movement of salty brine between underground formations. The call to pause injection was a "proactive move," ADM said then.

EPA had issued the proposed enforcement order to ADM less than two weeks prior, alleging the company had not complied with provisions of its Class VI well permit and allowed CO2 and formation fluids to migrate into "unauthorized zones." ADM has attributed the leak, which it detected last March, to corrosion in a monitoring well.

ADM initially said the amount of "cumulative fluid" that migrated is 8,000 metric tons but later put the estimate at between 2,670 metric tons and 3,940 metric tons. Anderson underscored there was never an impact to surface or groundwater sources.

The company maintains that its monitoring program worked to "detect, report, and address an anomalous condition."

"We continue to be confident in the safety, security and effectiveness of CCS as a greenhouse gas mitigation technology and its potential to bring new industries and economic opportunities to the entire state of Illinois," Anderson at ADM said.

Since stopping injections on Sept. 26, the company has vented CO2 from its ethanol plant into the atmosphere "in accordance with the facility’s air permit," ADM said in an emailed response to questions. An estimated 450,000 metric tons of carbon could have been captured and stored since that time, the company said.

Anderson said ADM is updating its monitoring approach and will "no longer rely on multi-zone monitoring in a single well," instead using separate wells to monitor "above and within a CO2 storage formation."

The company said it is also addressing the root of the incident. POLITICO reported last June that the leak was most likely caused by the corrosion of a steel known as 13 Chrome.

EPA's rule for Class VI wells, finalized in December 2010, doesn’t mention what type of steel should be used, instead saying, "casing and cement or other materials used in the construction of each Class VI well must have sufficient structural strength and be designed for the life of the geologic sequestration project."

In an email last year, EPA told companies that 13 Chrome and a type of cement used to secure pipes "are NOT suitable for construction of these wells in most instances," particularly under potentially corrosive conditions when both water and CO2 are present.

Instead, EPA in the email recommended Chromium-25 and another alloy, which the agency said are "generally better suited to environments in which both water and CO2 are present."

This month, Anderson at ADM said the company "plans to use either 22+ chrome steel or alloys of comparable corrosion resistance where warranted." 25 Chrome has also been used on a recompleted verification well, she said.

Stolark at the Carbon Capture Coalition said current EPA regulations are "flexible" when it comes to the materials that are used for the well casing.

"EPA requires operators to provide evidence on why particular materials are appropriate for the target zone of injection, and for the lifetime of the storage project," Stolark said in a statement, noting that well operators have a "vested interest" in using the best materials as halting carbon injection is a costly and time-intensive process.

On Wednesday, EPA spokesperson Brigit Hirsch said the agency hasn’t "issued guidance approving or prohibiting specific materials" for construction of Class VI wells.

"The agency is taking steps to ensure consistent communication that review of Class VI permit applications must consider whether well materials are appropriate for the conditions to which they will be exposed," Hirsch said.

The agency’s Class VI requirements don’t "prescribe specific metallurgy" for construction of the well type, Hirsch added.

Rules and oversight

Since EPA issued the proposed enforcement order in September, ADM has posted updates on its website every few months, with the most recent post in May.

"ADM has made a concerted effort to reach out to elected officials since last fall and provide updates," said David Horn, a member of the Decatur, Illinois, City Council. "The EPA should improve its communication with elected officials and residents regarding what happened and what steps the EPA is taking to make sure it will not happen again."

Among the lawmakers kept in the loop is Rep. Nikki Budzinski (D-Ill.), whose district includes the city of Decatur.

"ADM and the U.S. EPA have communicated to my office that they have agreed on steps to strengthen the safety of carbon capture and storage operations before moving forward with additional injection, with strong EPA oversight at every step of the way," Budzinski said in a statement.

Horn said he supports the restart of CO2 injection at ADM’s Decatur site as long as the company has met all of the conditions that EPA has laid out.

And while he said CO2 storage underground "could be a promising tool to reduce greenhouse gas emissions" and ADM has been a leader in that space, "it will be important for ADM to work with the city in developing a plan in the event of an emergency."

On Tuesday, Horn said ADM and the city are moving forward in creating such a plan.

"I am not aware that the City of Decatur has a mitigation plan in the event of a significant CO2 surface leak such as the one that occurred in Satartia, Mississippi," Horn said, referencing a 2020 rupture in Mississippi that prompted the Biden administration to introduce proposed safety regulations for carbon dioxide pipelines.

The Trump administration has withdrawn that rule.

Horn said he doesn’t support a Class VI injection well if the CO2 plume would go under Lake Decatur.

Richart, with the Eco-Justice Collaborative, said there are a range of outstanding questions about what’s transpired since EPA's proposed order in September, including around any remedial work that’s happened and the type of steel being used for monitoring wells.

"I think there’s a whole host of things we don’t know, and after [ADM] had a leak — and they weren’t transparent and they didn’t notify the public — I think we deserve to know what’s going before they begin injection again," she said.