IL SB3979

Requires all decarbonization pilots, pathways, and infrastructure plans under the Illinois Commerce Commission's "Future of Gas" proceeding (Docket No. 24-0158) to undergo a Regulatory Takings Assessment before approval

Mandates the assessment be conducted by an independent third party and evaluate whether proposed mandates (such as full electrification or renewable natural gas adoption) deprive property owners, utilities, or customers of economic use of gas infrastructure without just compensation

Prohibits approval of any decarbonization mandate that risks creating a taking without compensation equivalent to at least 80% of depreciated asset value

Requires the Commission to coordinate with the Environmental Protection Agency on air pollution standards and establish uniform metrics for decarbonization plans, including bill impacts and equity analyses

Rulemaking must be completed by June 1, 2026, with rules applied to all Phase 2C proposals under the Future of Gas proceeding