Department of the Interior Finalizes Major Overhaul of NEPA Implementing Regulations

Key Takeaways 

• The Department of the Interior (DOI) has finalized a sweeping revision of its regulations implementing the National Environmental Policy Act (NEPA), marking one of the most significant changes to DOI’s environmental review procedures since the Department first codified its NEPA regulations in 2008.  
• While some provisions were retained, key changes include the transition of NEPA procedures to the DOI Handbook rather than the Code of Federal Regulations, new standards for environmental effect analysis, and opportunities for public comment at the discretion of a “responsible official.”
• Project proponents and stakeholders must consider both the opportunities for increased efficiency and the reliability of these new procedures governing environmental review of proposed agency actions. 

Background 

DOI’s final rule follows an interim final rule (IFR) issued on July 3, 2025,[1] and responds to several converging legal and policy developments. First, the Council on Environmental Quality (CEQ) rescinded its government-wide NEPA implementing regulations effective April 11, 2025,[2] following Executive Order 14154, “Unleashing American Energy,” which revoked the executive order that had delegated NEPA rulemaking authority to CEQ.[3] Because DOI’s prior NEPA regulations were expressly designed to supplement CEQ’s regulations, the rescission necessitated that DOI adopt new standalone procedures. Second, the final rule aligns DOI’s procedures with the 2023 amendments to NEPA enacted through the Fiscal Responsibility Act (FRA), which imposed mandatory deadlines and page limits for environmental documents. Third, the rule responds to the Supreme Court of the United States’ 2025 decision in Seven County Infrastructure Coalition v. Eagle County, Colorado, which reiterated that NEPA is a “purely procedural statute” and refined the standard of judicial deference to agency judgments on scope of effects analysis required under the statute.[4] 

The final rule is effective upon publication in the Federal Register. DOI has indicated that revised procedures will have no effect on ongoing NEPA reviews, where DOI, following CEQ guidance, will continue to apply preexisting procedures to applications that are sufficiently advanced.  

Key Changes 

Transition From Regulation to Handbook 

The most fundamental change is DOI’s decision to relocate the majority of its NEPA procedures from the Code of Federal Regulations to the Department of the Interior Handbook: National Environmental Policy Act Implementing Procedures (DOI NEPA Handbook). This change replaces agency interpretations of regulations, which are entitled to deference, with general guidelines that delegate significant discretion to officials for how to interpret and implement NEPA on a case-by-case basis. DOI explains that this shift, which returns the department to its pre-2008 approach, provides greater flexibility to adapt procedures in response to the rapidly evolving legal landscape.  

Statutory Deadlines and Page Limits 

The DOI NEPA Handbook incorporates the mandatory deadlines and page limits enacted in the 2023 NEPA amendments.[5] Environmental assessments (EAs) must generally be completed within one year of the triggering event, while environmental impact statements (EISs) must be completed within two years. EISs are limited to 150 pages, or 300 pages for actions of extraordinary complexity, with citations and appendices excluded from the page count. Congress provided project sponsors with a cause of action to seek judicial review if an agency fails to meet the deadlines for completion of environmental review. 

Effects Analysis 

The DOI NEPA Handbook reorients the analysis of environmental effects around the Supreme Court’s guidance in Seven County Infrastructure Coalition, focusing on effects that are “reasonably foreseeable” and have a “reasonably close causal relationship” to the proposed action.[6] The handbook provides that bureaus “may, but [are] not required to by NEPA, analyze environmental effects from other projects separate in time, or separate in place, or that fall outside of the bureau’s regulatory authority, or that would have to be initiated by a third party.” DOI has moved away from the terminology of “direct,” “indirect,” and “cumulative” effects, which DOI characterizes as artificial distinctions not found in the statute.  

Under Section 1.2 of the DOI NEPA Handbook, decision-makers may also now formally weigh the degree to which an action will have “economic effects” against environmental impacts. This analysis can include aspects such as job creation and wages, property values, and other economic factors. 

Public Participation 

DOI’s revised procedures reflect only those public participation requirements mandated by statute. NEPA, as amended by the FRA, requires agencies to solicit public comment in only one specific circumstance: when an agency issues a notice of intent to prepare an EIS.[7] DOI’s procedures incorporate this requirement but do not mandate public comment on draft environmental documents or EAs. DOI explains that the CEQ regulations required more public involvement than the NEPA statute mandates. However, bureaus still have the authority to request additional public comments if they believe it is appropriate or useful, and DOI notes they have continued to do so voluntarily since the IFR was issued. 

Provisions Retained in Regulation 

DOI has retained a limited number of provisions in regulation at 43 C.F.R. Part 46, including emergency responses (Section 46.150); categorical exclusions and extraordinary circumstances (Sections 46.205, 46.210, and 46.215); applicant- and contractor-prepared environmental documents (Sections 46.105 and 46.107); and procedures for designating lead agencies and selecting cooperating agencies (Sections 46.220 and 46.225). The agency explains that it retained these provisions in regulation to ensure stability and provide a durable framework for tools that bureaus rely on to expedite reviews. See below for detailed information on how these retained sections changed. 

1. Categorical Exclusions

The final rule provides that bureaus may rely on categorical exclusion determinations made by other agencies for substantially the same action without conducting their own extraordinary circumstances review, provided they document such reliance. Bureaus may also apply multiple categorical exclusions in combination to cover a proposed action composed of multiple action elements, provided they verify that each element is supported by a categorical exclusion and complete extraordinary circumstances review for the composite action as a whole.  

Section 46.210 lists departmental categorical exclusions, and the final rule reinstates categorical exclusions for hazardous fuels reduction activities using prescribed fire (up to 4,500 acres) and post-fire rehabilitation activities (up to 4,200 acres), which had been removed in the IFR.  

2. Revised Extraordinary Circumstances 

DOI has revised the list of extraordinary circumstances that preclude reliance on a categorical exclusion. The final rule removes the provision addressing actions that may have “highly controversial environmental effects or involve unresolved conflicts concerning alternative uses of available resources,” which DOI found caused confusion and was misunderstood to mean that any controversy surrounding an action—rather than controversy about the nature or magnitude of environmental effects—constitutes an extraordinary circumstance. The rule also removes the extraordinary circumstances for actions that may violate a federal, state, local, or tribal law imposed for the protection of the environment, reasoning that legal compliance is distinct from the evaluation of environmental effects under NEPA. The extraordinary circumstance related to environmental justice was previously removed following the rescission of Executive Order 12898.[8]  

3. Applicant-Prepared Environmental Documents 

Section 46.107 establishes procedures for responsible officials to allow applicants or applicant-directed contractors to prepare EAs and EISs under bureau supervision, based on the FRA’s requirement that agencies develop procedures to allow a project sponsor to prepare these environmental documents. Responsible officials retain discretion over whether to allow applicant preparation and remain responsible for the accuracy, scope, and content of the environmental document. Applicants must submit a professional integrity statement certifying that the analysis is prepared with professional and scientific integrity, as well as a disclosure statement specifying any financial or other interest in the outcome of the action. Bureaus must independently evaluate and verify that the environmental analysis meets applicable standards.  

4. Lead and Cooperating Agencies 

In response to public comments, DOI recodified provisions for designating lead agencies and selecting cooperating agencies. Lead bureaus must invite eligible federal, state, tribal, or local agencies to participate as cooperating agencies when developing an EIS and may do so when developing an EA. Requests for cooperating agency status cannot be arbitrarily denied, and any denial must be explained in the environmental document.  

5. Emergency Responses 

Section 46.150 authorizes bureaus to take actions necessary to address imminent threats to life, property, or important natural, cultural, or historic resources without first preparing an environmental document or documenting use of a categorical exclusion. The final rule clarifies that NEPA’s analysis and documentation requirements should not impede timely execution of emergency actions, though the responsible official should consider probable environmental consequences and take steps to mitigate reasonably foreseeable adverse effects to the extent practicable. For additional actions beyond those immediately necessary, alternative arrangements for NEPA compliance may be authorized.  

Practical Implications 

Project proponents and stakeholders should be aware of several practical implications. The transition to a handbook-based approach may provide DOI greater discretion to modify procedures without formal rulemaking, which could lead to evolving practices over time. Applicants may seek to take advantage of the procedures for applicant-prepared environmental documents, which can help ensure that project-specific information is incorporated efficiently and that document preparation stays on track. The statutory deadlines create both opportunities and obligations—project sponsors now have a judicial remedy if agencies fail to meet deadlines, but all parties should plan accordingly to meet the compressed timeframes. The reduced public comment requirements may accelerate reviews but could also leave environmental analysis vulnerable to challenges, including litigation over final decisions. Finally, stakeholders should monitor the DOI NEPA Handbook and bureau-specific guidance for updates, as changes to these nonregulatory documents may occur more frequently than changes to codified regulations.  

This Update is for informational purposes only and does not constitute legal advice. For questions about how these changes may affect specific projects or activities, please contact our team. 

Endnotes

[1] National Environmental Policy Act Implementing Regulations, 90 Fed. Reg. 29498 (Jul. 3, 2025).

[2] 90 Fed. Reg. 10610 (Feb. 25, 2025).

[3] Exec. Order No. 14154, 90 Fed. Reg. 8353 (Jan. 20, 2025).  

[4] Seven County Infrastructure Coalition v. Eagle County, Colorado, 605 U.S. 168 (2025). 

[5] 42 U.S.C. 4336a. 

[6] Seven County, 605 U.S. at 188.  

[7] 42 U.S.C. 4336a(c).

[8] Exec. Order No. 14173, 90 Fed. Reg. 8633 (Jan. 21, 2025).