The EPA recently issued an Advanced Notice of Proposed Rulemaking (ANPRM) to request information and comments that may inform upcoming rulemaking to revise the existing Regional Haze Rule (RHR). The EPA last revised the RHR in 2017 to clarify the relationship between long-term strategies and reasonable progress goals in SIPs and the long-term obligation of all states.
The ANPRM requests input on three key topic areas for the Regional Haze program: (1) development and use of reasonable progress metrics and consideration of the four statutory reasonable progress factors,[1] (2) development of the criteria used to determine when a SIP revision is required, and (3) determining SIP requirements for states that are required to submit a SIP revision. One of the main ideas EPA seeks comment on is whether EPA should consider developing an objective and numerically-based reasonable progress metric (called a ‘‘Safe Harbor’’) that informs whether a SIP revision is necessary, and which additional measures may be necessary to make reasonable progress in the SIP.
[1] The four statutory factors are used to evaluate and determine potential emissions reductions. The statutory factors are: “the costs of compliance, the time necessary for compliance, and the energy and non-air quality environmental impacts of compliance, and the remaining useful life of any existing source subject to such requirements.” CAA § 169A(g)(1); 42 U.S.C. § 7491.
EPA’s Advance Notice of Proposed Rulemaking on the Visibility Protection: Regional Haze State Plan Requirement Rule Revision: Docket Number EPA-HQ-OAR-2025-1477.
The comment deadline is December 1, 2025. Your comment letter can be submitted electronically to the Federal Rulemaking Portal. https://www.regulations.gov/ OR email to a-r-Docket@epa.gov.
NTAA’s PRK
- NTAA Tribal Template Letter – A template word document that includes NTAA’s comments that can be used by Tribes to submit to the EPA.
- NTAA Fact Sheet – A fact sheet that can be used by Tribes to inform community members and leadership regarding this proposal.
- NTAA Comment Letter – The official letter NTAA submitted to the EPA in response to the rule.