LNT · 10-Q · 2026Q3 · Full report

Environmental Rule Changes

ALLIANT ENERGY CORP · 2026-10-30 · Importance null · Surprise 42

In April 2026, the EPA proposed narrowing the scope of the Coal Combustion Residuals Rule, with finalization anticipated by year-end 2026; Alliant Energy, IPL, and WPL said they could not yet predict the outcome or impact, including ongoing litigation. In May 2026, the EPA proposed changes to the 2024 Effluent Limitation Guidelines, also expected to be finalized by year-end 2026, that would revise wastewater discharge limits for certain existing steam EGUs. In September 2026, the EPA finalized repeal of Clean Air Act Section 111(d) emission guidelines that would have imposed compliance requirements beginning in 2030. The EPA also partially repealed Section 111(b) standards in September 2026, removing carbon-capture-based standards effective by January 1, 2032 while leaving certain low-emitting fuel and efficiency requirements in place for new EGUs.

Key facts

• The EPA’s April 2026 proposed CCR rule would significantly reduce the rule’s scope and was anticipated to be finalized by the end of 2026; Alliant Energy could not predict the outcome or impact, including resolution of ongoing litigation.
• In May 2026, the EPA proposed changes to the 2024 ELG Rule, anticipated to be finalized by the end of 2026, that would revise discharge limits for certain wastewater categories from existing steam EGUs.
• Alliant Energy, IPL and WPL expected to adopt the environmental credits accounting standard on January 1, 2028, applying it retrospectively through an adjustment to opening retained earnings.
• In September 2026, the EPA finalized repeal of Clean Air Act Section 111(d) emission guidelines for existing fossil-fueled EGUs; the guidelines would have imposed compliance requirements beginning in 2030 on certain Alliant Energy facilities.
• In September 2026, the EPA partially repealed the 2024 revised Clean Air Act Section 111(b) standards, removing carbon-capture-based standards that would have taken effect by January 1, 2032, while certain standards for newly constructed fossil-fueled EGUs remain in effect.
• Alliant Energy, IPL and WPL did not anticipate a material increase in environmental credit assets or obligations upon adoption of the standard.