Environmental Protection Agency · EPA-R09-OAR-2025-3821
Air Plan Approval; Arizona; Attainment Plan for the Hayden SO2 Nonattainment Area for the 1971 and 2010 Sulfur Dioxide National Ambient Air Quality Standards
The Federal Register published the matched proposal on March 4, 2026 and the matched final rule on August 20, 2026, 169 days later.
Official publication history
Proposal ·
Air Plan Approval; Arizona; Attainment Plan for the Hayden SO2 Nonattainment Area for the 1971 and 2010 Sulfur Dioxide National Ambient Air Quality Standards
Comment date listed April 3, 2026
Final rule ·
Air Plan Approval; Arizona; Attainment Plan for the Hayden SO2 Nonattainment Area for the 1971 and 2010 Sulfur Dioxide National Ambient Air Quality Standards
Effective date in register data September 21, 2026
About this timeline
How the records were matched
America.co links a proposed rule and a later final rule when the Federal Register records share the exact docket identifier and lead agency. This snapshot covers records published from January 1, 2025 to November 10, 2026.
A docket can hold more than one regulatory action. Dates here are dates listed in individual notices. Later corrections, court actions, other dockets and records outside the date window may change what applies. Follow the official documents for the full text and effective dates.
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