The Illinois State Geological Survey (ISGS) at the University of Illinois at Urbana-Champaign, along with partners including Schlumberger Carbon Services, Indiana Geological Survey, Brigham Young University, and Richland Community College, will work to establish the feasibility of a commercial-scale CO₂ geologic storage complex within the Mt. Simon sandstone formation located in Macon County, Illinois. The project is part of the Storage Complex Feasibility phase of the Carbon Storage Assurance Facility Enterprise (CarbonSAFE) Initiative which aims to perform initial characterization of carbon capture and storage (CCS) complexes with potential for 50 million tonnes or more of industrial-sourced CO₂, and to establish feasibility of the complexes for commercial storage (Figure 1). The project team will conduct a commercial-scale initial characterization of a site within the Mt. Simon storage complex and develop datasets of formation parameters in order to evaluate the suitability of the site for CCS. A stratigraphic test well will be drilled in the Forsyth Oil Field to establish the potential capacity for this complex. Static and dynamic modeling will be used to examine the performance of the site and evaluate it for long-term security. The models will be used to identify improvements in storage capacity estimations. A detailed plan will be prepared for further characterization requirements to reduce subsurface uncertainty at this site and for continued work toward commercialization of storage complexes. Public outreach components and permitting requirements, legal issues, and contractual issues will be considered for the project. The project will work towards the DOE objective of producing a feasible CCS stacked storage complex in the Illinois Basin region.