The Illinois Senate has unanimously approved a bill that would ban carbon sequestration activities near the Mahomet Aquifer, the primary source of drinking water for nearly one million residents in central Illinois. The measure, which passed 55-0, responds to mounting concerns from local communities and environmental groups about the potential risks carbon capture technology poses to the region’s water supply. The bill now moves to the Illinois House for consideration.
Carbon capture and sequestration (CCS) is a process designed to reduce greenhouse gas emissions by capturing carbon dioxide and storing it deep underground. While some see CCS as a promising climate solution, critics have raised alarms about its safety.
In July 2024, Illinois Governor JB Pritzker signed Senate Bill 1289 into law, which allowed carbon sequestration activities—including the underground injection and storage of carbon dioxide—under the Mahomet Aquifer, despite its status as the region’s sole source of drinking water. This decision was met with strong opposition from local legislators, environmental groups, and community advocates, who warned that the bill failed to include adequate protections for the aquifer and could expose nearly one million residents to potential water contamination risks.
Critics pointed out that SB1289 did not ban carbon sequestration beneath the Mahomet Aquifer, leaving it vulnerable to leaks or accidents that could threaten water quality. The controversy intensified after leaks were reported at a nearby carbon sequestration facility in Decatur.
In response to these concerns and the perceived shortcomings of SB1289, new legislation was introduced in 2025 to explicitly prohibit carbon sequestration activities over, under, or through the Mahomet Aquifer, aiming to close the loopholes left by the previous year’s law.
The bill amends the Environmental Protection Act to prohibit any carbon sequestration activity within a sequestration facility that overlies, underlies, or passes through a sole-source aquifer, specifically targeting the Mahomet Aquifer area. The legislation defines key terms such as “carbon sequestration activity,” “sequestration facility,” and “sole source aquifer,” and establishes strict permitting requirements for any CCS projects elsewhere in the state.
The bill’s scope was narrowed through a late amendment, limiting the ban to the Mahomet sole source aquifer area rather than the broader project review area. This change drew criticism from some environmental groups, including Illinois People’s Action, which argued that the amendment weakened the bill’s original intent and left some communities at risk.
The bill now awaits a vote in the Illinois House. If approved, it would establish some of the nation’s most stringent protections against carbon sequestration near vital water sources. The measure also creates the Mahomet Aquifer Advisory Study Commission, which will study the safety of carbon capture and storage in the region and provide ongoing public reports through 2031.
