Air Plan Disapproval; Colorado; Regional Haze Plan for the Second Implementation Period

What it does

The Environmental Protection Agency (EPA) is disapproving a regional haze state implementation plan (SIP) revision submitted in 2022 by the State of Colorado under the Clean Air Act (CAA or Act) and the EPA's Regional Haze Rule (RHR) for the program's second implementation period. Colorado's 2022 regional haze SIP revision addresses the requirement that states revise their long-term strategies every implementation period to make reasonable progress towards the national goal of preventing any future, and remedying any existing, anthropogenic impairment of visibility, including regional haze, in mandatory Class I Federal areas (Class I areas). We are disapproving Colorado's 2022 regional haze SIP revision pursuant to the CAA and regulatory regional haze requirements. The EPA is not taking final action at this time on a separate revision to Colorado's SIP that consolidates existing, previously approved regional haze provisions into the same regulation where Colorado's new, second planning period provisions are located.

The Environmental Protection Agency's summary, as published in the Federal Register.

What changed in the regulation

1 part of Title 40 of the Code of Federal Regulations:

40 CFR 52

Wording on eCFR: the day before it took effect and from the day it took effect (first part listed).

Compared with

The Environmental Protection Agency has published 248 final rules in 2026 so far, compared with 263 in all of 2025.

Counted by the Tribune from Federal Register records since Jan. 1, 2025.

What happens next and when

This rule is effective on February 25, 2026.

The agency's dates, word for word.

Check it yourself

• The document in the Federal Register
• Docket EPA-R08-OAR-2024-0607 on Regulations.gov
• Title 40 on eCFR

The record as published

Source: the Federal Register (public domain). The document in the Federal Register