ADM's leaks show why CO2 should not be stored under the Mahomet Aquifer
Central Illinois residents get their fresh water from the Mahomet Aquifer, a U.S. EPA-designated sole-source aquifer. This designation means that there is no readily-available supply of water should the aquifer become contaminated and that pollution of the aquifer would pose a significant health risk. That is why advocates say CO2 should never be stored the Mahomet Aquifer, and why we are asking the General Assembly for a Mahomet Aquifer Project Review Area Sequestration Ban.

But recent leaks at nearby ADM Decatur's CCS demonstration project underscore the importance of and need for a sequestration ban. Simply put - the Class VI well permit process, intended to ensure the safe and permanent underground storage of CO2, failed. While it is true that at ADM says there is no threat to drinking water, the technical and operational failures and lack of oversight by the U.S. EPA confirm the risks of this technology.  With a sole-source aquifer like the Mahomet, there needs to be ZERO risk to all who rely on it.

So What Happened?
In November of 2017, ADM began injecting CO2 into their Illinois Industrial Carbon Capture and Storage Project (ICCS) in Decatur, Illinois. This project followed the company's perceived successful storage of 1MMT between 2011 and 2014 as part of their Illinois Basin-Decatur Project. Plans were to store an additional 5 to 6 MMT CO2 to demonstrate the viability of carbon capture and sequestration at what they considered to be a commercial scale.

But on September 13, 2024, E&E News Politico's broke their story about ADM's leak at Monitoring Verification Well #2, and by October the company had determined that their second monitoring well (Monitoring Verification Well #1) had leaked. These failures happened at a research development project funded, in part, by the federal government, that was intended to show CO2 could be safely injected, stored, and monitored. These leaks, although small, call into question whether any profit-driven corporation and the U.S. EPA are capable of ensuring sequestration projects will not put the public at risk.

Here's a deeper dive into what took place. All information is publicly-available from ADM semi-annual and annual reports to the EPA and ADM's response to the EPA's well inspection and Notice of Violation.

• In September of 2020, fewer than three years after injection began, MVW#2 began to experience intermittent electrical failures.

• By January 2022, all gauges were malfunctioning.

• In February of that year, the EPA met with ADM to discuss what could be done to repair and restore the well.

• Some time in 2022 MW#2 leaked CO2 (subsurface leak). ADM partially plugged the well, which prevented them from sampling in two of the required five zones. They continued to try to repair the well.

• After failing to restore its capabilities by October 2023, ADM began to pull the well’s piping and discovered corrosion. In October of that year, the company plugged MV#2 and took it out of production. That meant the project was operating with just one of two required monitoring wells.

Reports that address what happened between October 2023 and the time the leak was discovered are not yet available. But we do know from the EPA's inspection report and media reports about the incident that:

• The EPA inspected all wells associated with ADM's two projects in June of 2024.

• In a June 25 email, EPA told companies that are currently applying to EPA for carbon injection well permits that 13 Chrome and a type of cement commonly used by the industry to secure those pipes “are NOT suitable for construction of these wells in most instances, particularly under potentially corrosive conditions when both water and CO2 are present.”

• On August 14, 2024, the EPA issued ADM a Notice of Violation, asserting the company had the company conducted activity that allowed injection and formation fluids into "unauthorized zones," failed to follow an emergency response and remediation plan, and did not “monitor the well in accordance with the Permit."violated the terms of their permit.

• On September 13, E&E News released their story about a March 2024 leak in the Ironton-Galesville formation above the caprock.

• On September 19, the U.S. EPA issued a Proposed Order on Administrative Consent, requiring ADM to repair and restore the leaking well and bring their project back into compliance with their approved permit.

• In October, while conducting tests, ADM learned and reported that their second well, MVW#1, was leaking. They did not detect corrosion and stated the leak was brine, and not CO2.  The company decided to stop injecting CO2.

• On November 5, E&E News reported that ADM had identified 24 wells in the vicinity of their ICCS project that could provide paths for CO2 to leak. Dan Arthur, former U.S. EPA enforcement officer said these wells could affect subsurface flow of CO2, making it more difficult to tell where CO2 would migrate.

While ADM continues to claim that at no time did these leaks threaten any underground source of drinking water (USDW), it will take more time and research to fully understand the scope of these leaks, including the threat they may pose to a USDW.

ADM failed, but so did the EPA
The monitoring well leaks that occurred at ADM’s ICCS storage site in Decatur were due to material, design, and operational failures of Monitoring Well #2 - and later, Monitoring Well #1. But just as concerning as ADM’s failures are those of the EPA:

• The EPA approved 13 chrome steel, which they knew it would be used in a highly corrosive environment, and a design that allowed the transport of CO2 from the Mt. Simon Formation to the Ironton-Galesville formation above the cap-rock.

• The EPA did not issue a notice of violation when ADM's Monitoring Verification Well #2 was plugged due to corrosion (and likely leaking) and taken out of production in October 2023, leaving them with just one of two required monitoring wells.

• The EPA did not require ADM to stop injecting CO2 per the company’s EPA-approved emergency response plan. Injection was allowed to continue with just one monitoring well for a full year before ADM voluntarily paused CO2 injection after they learned their second monitoring well had leaked.

The ONLY operating Class VI well project in the U.S. that has been permitted by the U.S. EPA is the Illinois Industrial Carbon Capture and Storage Project in Decatur. And it leaked.

Help us pass a legislative ban
Governor Pritzker signed Public Act 103-0651, legislation regulating carbon capture and storage on July 18, 2024.  But the law does not ban the injection of CO2 through or storage under the Mahomet Aquifer and its recharge areas, despite the request by 12 senators and representatives to do so.

This leaves the Mahomet vulnerable to contamination from a CO2 leak. The only way to protect the Mahomet Aquifer Project Review Area is to pass a legislative sequestration ban. Eco-Justice Collaborative and its partners, Prairie Rivers Network, Illinois People's Action, the Sierra Club Prairie Group are asking counties and cities to pass resolutions that urge the General Assembly to pass a Mahomet Aquifer Project Review Area Sequestration Ban. We also are asking counties located in the footprint of the aquifer's Project Review Area to ban injection of CO2 through and storage of it under the aquifer.

Can you help? Click here for more information and a list of communities and counties that have - or are in the process of adopting resolutions and bans.

Questions?  Contact Pam at prichart@ecojusticecollaborative.org.

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Download and read this summary prepared by Eco-Justice Collaborative and distributed to Illinois' Senate Executive Committee, explaining why these leaks demonstrate why the General Assembly should pass a Mahomet Aquifer Project Review Area Sequestration ban to protect this sole-source aquifer from CO2 pollution.

Download and review this slide deck that explains the threats to the Mahomet Aquifer and its Project Review Area from injecting CO2 and storing it under this sole-source aquifer.