Regional Haze State Implementation Plans

Current understanding

To be populated as evidence accumulates.

2026-09-17 — Rescission of the Greenhouse Gas Findings for Fossil Fuel-Fired Power Plants and Repeal of Regulations for Power Plant Greenhouse Gas Emissions Under Clean Air Act Section 111: cross-connection with power-plant-ghg-endangerment-finding-rescission: Regional haze BART/second-period reviews on coal EGUs become the primary remaining federal driver of emission-control investment at fossil power plants if §111 GHG standards are repealed. (novelty: 4)
2026-09-09 — Air Plan Approval; Reconsideration and Repeal of Air Plan Partial Approval and Partial Disapproval of North Dakota’s Regional Haze State Implementation Plan for the Second Implementation Period: EPA proposed rule (Nov 2025) would repeal its December 2024 partial disapproval of North Dakota’s 2022 regional haze SIP for the second implementation period and instead fully approve the plan, reversing the earlier finding that portions failed to meet reasonable-progress requirements for NOx and SO2 controls at affected sources. (novelty: 2)