EPA OKs Illinois Carbon‑Storage Permit

The Environmental Protection Agency has approved a federal permit for Marquis Carbon Injection to store carbon dioxide underground in Putnam County, Illinois. (epa.gov) The permit, issued April 10, 2026, allows one injection well at the company’s proposed site near Hennepin to store up to 1.5 million metric tons a year for six years, or 9 million metric tons total. (epa.gov) Carbon sequestration means capturing carbon dioxide before it reaches the air and pumping it deep underground into rock layers meant to hold it in place. The Environmental Protection Agency said this project’s storage zone sits about 3,094 to 4,854 feet below the surface. (epa.gov) The agency said the storage interval is separated from drinking-water sources by about 963 feet of rock, including a confining layer about 404 feet thick made of shale and carbonate rock. Environmental Protection Agency Region 5 Administrator Anne Vogel said the permit includes “stringent safeguards and long-term monitoring” for underground drinking water. (epa.gov) The permit does not end with injection. Marquis must monitor the well during the six-year injection period and for 12 years afterward to show the carbon dioxide stays in the approved zone. (epa.gov) This approval closes a federal review that moved into public comment on September 8, 2025. The Environmental Protection Agency held a public availability session on October 15 and a public hearing on October 29 at Putnam County High School in Granville, with comments due by November 3. (epa.gov) The permit is a Class VI permit under the Safe Drinking Water Act, the federal program used for wells that inject carbon dioxide for long-term geologic storage. The Environmental Protection Agency says final permits authorize construction or conversion of the injection well and required monitoring wells. (epa.gov, epa.gov) The draft permit fact sheet said the Marquis project would include two deep monitoring wells, one well above the confining zone, and five shallow groundwater monitoring wells in aquifers less than 300 feet deep. (epa.gov) Supporters tied the permit to the local ethanol economy. Representative Darin LaHood said the project is “a win for agriculture, manufacturing, and biofuels industries in Putnam County and across the region.” (epa.gov) Opponents have focused on groundwater risk in a county where many communities rely on wells. The Illinois chapter of the Sierra Club said Putnam County towns and places across the Illinois River in Bureau County depend on groundwater and urged residents to scrutinize the project. (sierraclub.org) For Marquis, the federal permit clears the underground-storage piece of the project after months of review, public hearings and technical filings. The next phase is construction and testing under the permit’s operating, monitoring and reporting conditions. (epa.gov, epa.gov)