Company: AILIM
Filing Date: 2025-02-18
Form Type: 10-K
Source: 0001002910-25-000055
Chunk: 117

Company: Ameren Illinois Co
Filing Date: 2025-02-18
Form: 10-K
Item: Item 8
Chunk 117
---
ments at Ameren Missouri’s coal-fired energy centers are subject to closure and groundwater monitoring requirements and the implementations of corrective measures if necessary. The individual or combined effects of compliance with existing and new environmental regulations could result in significant capital expenditures, increased operating costs, or the closure or alteration of operations at some of Ameren Missouri’s energy centers. Ameren and Ameren Missouri expect that such compliance costs would be recoverable through rates, subject to MoPSC prudence review, but the timing of costs and their recovery could be subject to regulatory lag.Additionally, Ameren Missouri’s wind generation facilities may be subject to operating restrictions to limit the impact on protected species. Since 2021, Ameren Missouri’s High Prairie Energy Center curtailed nighttime operations from April through October to limit impacts on protected species during the critical biological season. The extent and duration of future curtailments are currently unknown as assessment of mitigation technologies is ongoing. In Ameren Missouri’s 2024 electric service regulatory rate review, the MoPSC staff and the MoOPC have recommended reductions to the revenue requirement associated with the nighttime curtailment of the High Prairie Energy Center. See Note 2 – Rate and Regulatory Matters for additional information.Ameren and Ameren Missouri estimate that they may need to make capital expenditures of $900 million to $1 billion from 2025 through 2029 to comply with environmental regulations. Additional capital expenditures for environmental controls beyond 2029 could be required. These estimates include capital expenditures that may be necessary to comply with regulations issued by the EPA in 2024 relating to CO2 emissions and MATS discussed below, assuming these regulations are not revised or overturned. This estimate of capital expenditures also includes surface impoundment closure and corrective action measures required by the 2015 CCR Rule and modifications to cooling water intake structures at existing power plants under Clean Water Act rules in place prior to 2024, all of which are discussed below. Congress and the EPA could review and revise compliance requirements. In addition to planned retirements of coal-fired energy centers that will be included in Ameren Missouri’s 2025 Change to the 2023 PRP and as noted below with respect to the NSR and Clean Air Act litigation and Illinois emissions standards, Ameren Missouri’s current plan for compliance with existing air emission regulations includes burning low-sulfur coal and installing new or optimizing existing air pollution control equipment. Accordingly, the actual amount of capital expenditures required to comply with existing environmental regulations may vary substantially from the above estimates