Company: AILIM
Filing Date: 2025-05-05
Form Type: 10-Q
Source: 0001002910-25-000098
Chunk: 84

Company: Ameren Illinois Co
Filing Date: 2025-05-05
Form: 10-Q
Item: Part I, Item 1
Chunk 84
---
 requirements by state regulators and the EPA, revisions to regulatory obligations and their timing, and varying cost of potential compliance strategies, among other things.The following sections describe the significant environmental statutes and regulations and environmental enforcement and remediation matters that affect or could affect our operations. The EPA could ultimately revise all or part of such regulations.Clean Air ActFederal and state laws, including the CSAPR, regulate emissions of SO2 and NOx through the reduction of emissions at their source and the use and retirement of emission allowances available for state budgets. In April 2022, the EPA proposed the Good Neighbor Rule, which includes additional NOx emission reductions from power plants through revisions to the CSAPR and in January 2023, the EPA rejected Missouri’s proposed state implementation plan for addressing the transport of ozone under that rule. The EPA’s disapproval of states’ implementation plans and adoption of a federal implementation plan resulted in litigation in multiple appellate courts including the United States Court of Appeals for the Eighth Circuit and the United States Supreme Court. In February 2025, the EPA requested that the appellate courts suspend the Good Neighbor Rule cases indefinitely and indicated it was reviewing the basis for the disapproval of the state implementation plans, including Missouri’s. In February and April 2025, the appellate courts granted the EPA’s requests to suspend the Good Neighbor Rule cases. Ameren Missouri complies with the current CSAPR requirements by minimizing emissions with low-sulfur coal, operation of two scrubbers at its Sioux Energy Center, and optimization of existing NOx air pollution control equipment. Reducing the amount of state budget NOx allowances for compliance with NOx emission limits could result in the need for additional controls on Ameren Missouri’s generating units and/or the reduction of operations. Any costs for compliance are expected to be recovered from customers, subject to MoPSC prudence review, through the FAC or higher base rates.CO2 Emissions StandardsIn April 2024, the EPA issued a final rule that sets CO2 emission standards for existing coal-fired and new natural gas-fired power plants based on the emissions expected from adoption of carbon capture technology and/or natural gas co-firing for coal-fired power plants and carbon capture technology for new natural gas-fired power plants. Affected power plants are required to comply with the rule through a phased-in approach or retire. Compliance with the new rule could be required as early as 2030 for certain existing coal-fired power plants and 

29

2032 for certain new natural gas-fired power plants. Litigation regarding the rule has