The Statutory Framework

The National Environmental Policy Act of 1969 (NEPA), codified at 42 U.S.C. §§ 4321–4370m, requires federal agencies to evaluate the environmental effects of proposed federal actions before making decisions. At airports, a "federal action" triggering NEPA includes any project that involves federal funding (AIP grants, BIL grants), FAA approval of an Airport Layout Plan (ALP) change, or another discretionary FAA decision such as an airspace determination or Part 139 certification action.

Since 2023, NEPA has been amended three times:

1. Fiscal Responsibility Act of 2023 (Pub. L. 118-5, June 3, 2023) — imposed mandatory time and page limits on EAs and EISs, narrowed the scope of required analysis to "reasonably foreseeable" effects, and redefined "major federal action."
2. FAA Reauthorization Act of 2024 (Pub. L. 118-63, May 16, 2024) — created two new categorical exclusions for airport projects and expanded the streamlined environmental review process to include terminal development and all airport capacity enhancement projects.
3. One Big Beautiful Bill Act of 2025 (signed July 4, 2025) — created an opt-in expedited review mechanism: a project sponsor may pay the Council on Environmental Quality (CEQ) 125% of the anticipated cost of preparing a NEPA document in exchange for a 180-day deadline for EAs or a one-year deadline for EISs.

FAA's NEPA Implementing Orders

The FAA implements NEPA through two orders:

• FAA Order 1050.1G — FAA National Environmental Policy Act Implementing Procedures, effective July 3, 2025. This replaced Order 1050.1F (July 2015) and is the first update in a decade.
• FAA Order 5050.4B — NEPA Implementing Instructions for Airport Actions, April 2006. This airport-specific order is superseded by Order 1050.1G to the extent of any conflict, but may be used as a reference where it does not conflict.

Projects initiated on or after July 3, 2025 must comply with Order 1050.1G. Projects already underway as of that date may continue under Order 1050.1F.

Three Levels of NEPA Review

NEPA review for airport projects falls into one of three categories, each producing a different decision document:

Level	Document	Decision Document	When Used
Categorical Exclusion (CATEX)	Documented CATEX (or no documentation for routine actions)	CATEX determination	Actions within defined categories that do not individually or cumulatively cause environmental effects absent extraordinary circumstances
Environmental Assessment (EA)	EA document (max 75 pages)	Finding of No Significant Impact (FONSI); or determination that an EIS is required	Actions not categorically excluded where the level of environmental impact is uncertain
Environmental Impact Statement (EIS)	Draft EIS → Final EIS (max 150 pages)	Record of Decision (ROD)	Actions expected to have, or where an EA has shown, environmental effects that meet or exceed significance thresholds

Categorical Exclusions (CATEXs)

A CATEX is a category of actions that the FAA has determined, based on previous experience, do not individually or cumulatively cause effects that meet or exceed significance thresholds — except in the presence of extraordinary circumstances.

Airport Actions That Are Categorically Excluded

Under FAA Order 5050.4B and Order 1050.1G, airport actions that qualify for a CATEX include:

• Master plans and Part 150 noise compatibility studies
• Acquisition of safety or security equipment
• Pavement repair, maintenance, or reconstruction (with no change in airport layout)
• Installation or upgrading of airfield lighting systems
• Landscaping
• Land acquisition (without residential or business relocations or environmental impacts)
• Grading, removal of obstructions, and erosion control activities
• Federally funded noise insulation programs
• Construction of on-airport buildings (hangars, maintenance facilities) where no change in airport operations occurs

New CATEXs Under the 2024 Reauthorization

Section 788(a) of the FAA Reauthorization Act of 2024 created two new categorical exclusions, now incorporated into Order 1050.1G:

1. Limited federal assistance — Projects approved, permitted, financed, or authorized by FAA that receive less than $6 million of federal funds.
2. Emergency repair or reconstruction — Repair or reconstruction of any airport facility, runway, taxiway, or similar structure damaged in connection with a declared disaster or emergency.

Both new CATEXs remain subject to an extraordinary circumstances review — the FAA must evaluate whether conditions specific to the project elevate it beyond the categorical exclusion.

Extraordinary Circumstances

Even if an action falls within a recognized CATEX category, extraordinary circumstances may require elevation to an EA or EIS. Order 1050.1G retains the list of extraordinary circumstances from 1050.1F with one clarification: actions that are "likely to be highly controversial on environmental grounds" constitute an extraordinary circumstance only where the controversy relates to a substantive issue pertaining to the analysis of effects — not simply because a large number of persons oppose the project.

Environmental Assessments (EAs)

An EA is prepared when a proposed action is not categorically excluded and it is not clear whether the action will cause effects meeting significance thresholds. For airport projects, actions that commonly require an EA include:

• New runway construction
• Runway extensions (beyond what can be categorically excluded)
• Runway strengthening with potential off-airport noise impacts
• New or relocated instrument landing systems
• Land acquisition involving residential or business relocations
• Airport projects in or adjacent to wetlands, floodplains, or historic properties

EA Timeline and Page Limits

The Fiscal Responsibility Act of 2023 imposed a statutory deadline of one year for completion of an EA, beginning on the earlier of (a) the date the agency determines that an EA is required, or (b) the date the agency issues a notice of its intent to prepare the EA. EAs are limited to 75 pages, not including citations or appendices.

Under the One Big Beautiful Bill Act (July 4, 2025), if a project sponsor pays the 125% fee to CEQ, the EA deadline is shortened to 180 days from the date of fee payment.

EA Outcomes

An EA concludes with one of two outcomes:

• FONSI (Finding of No Significant Impact) — The FAA determines that the proposed action will not cause effects that meet or exceed significance thresholds. The project may proceed.
• Determination that an EIS is required — If the EA reveals that effects may meet or exceed significance thresholds and cannot be mitigated, the FAA determines that an EIS is required.

Environmental Impact Statements (EISs)

An EIS is the most detailed level of NEPA review. It is required when a proposed action is expected to have effects that meet or exceed one or more significance thresholds, or when an EA has disclosed such effects.

EIS Process Steps

1. Notice of Intent (NOI) — Published in the Federal Register, announcing the agency's intent to prepare an EIS and initiating the scoping process.
2. Scoping — Public and agency meetings to identify the range of issues, alternatives, and environmental resources to be addressed.
3. Draft EIS — The agency analyzes the proposed action, reasonable alternatives (including a no-action alternative), the affected environment, and the environmental consequences of each alternative.
4. Public Comment — The Draft EIS is circulated for a minimum 45-day public comment period.
5. Final EIS — Responses to substantive public comments are incorporated.
6. Record of Decision (ROD) — The agency's decision document, issued no sooner than 30 days after the Final EIS. The ROD identifies the selected alternative, presents the basis for the decision, describes mitigation commitments, and addresses whether all practicable means to avoid or minimize environmental harm have been adopted.

EIS Timeline and Page Limits

The Fiscal Responsibility Act imposed a statutory deadline of two years for completion of an EIS, measured from the earlier of (a) the date the agency determines an EIS is required, or (b) the date of publication of the NOI. EISs are limited to 150 pages, or 300 pages for actions of extraordinary complexity, not including citations or appendices.

Under the One Big Beautiful Bill Act's fee-based expedited review, the EIS deadline is shortened to one year from publication of the NOI.

For context, across all federal agencies, the median time from NOI to Final EIS for documents completed in calendar year 2024 was 2.2 years (26 months), an improvement from 3.6 years (43 months) in 2019.

Environmental Impact Categories and Significance Thresholds

FAA evaluates airport projects against a defined set of environmental impact categories. Order 1050.1G retains the categories from 1050.1F but moved significance thresholds to Appendix A with modifications. Key categories and their thresholds for airport projects:

Impact Category	Significance Threshold
Noise	A DNL increase of 1.5 dB or more over a noise-sensitive area exposed to or that will be exposed to aircraft noise at or above DNL 65 dB
Air Quality	Emissions exceeding de minimis thresholds under the General Conformity Rule (40 CFR § 93.153) — 100 tons/year for ozone precursors and other pollutants in nonattainment areas
Section 4(f) Resources	Physical or constructive use of publicly owned parks, recreation areas, wildlife/waterfowl refuges, or historic sites — unless a de minimis impact determination is made
Water Resources	Adverse impacts on surface water quality exceeding applicable standards; placement of fill in waters of the U.S. requiring a Section 404 permit
Biological Resources	Jeopardizing the continued existence of a federally listed threatened or endangered species or destroying/adversely modifying designated critical habitat
Historical/Cultural Resources	Adverse effect on properties listed or eligible for listing on the National Register of Historic Places
Compatible Land Use	For noise: residential or noise-sensitive land uses within DNL 65 dB contour that are incompatible under 14 CFR Part 150

Changes Under Order 1050.1G

Three categories that were required subjects of analysis under Order 1050.1F are no longer required under Order 1050.1G:

• Climate — No longer a required subject of analysis. Significance thresholds for climate have been eliminated.
• Environmental Justice — Removed as a required analytical category.
• Cumulative Impacts — No longer a mandatory topic. Order 1050.1G directs the analysis to focus on whether the environmental effects of the action at hand are significant.

The noise threshold (DNL 65 dB / 1.5 dB increase) remains unchanged.

Streamlined Review Under 49 U.S.C. § 47171

Section 783 of the FAA Reauthorization Act of 2024 amended 49 U.S.C. § 47171 to expand the streamlined environmental review process. Prior to this amendment, the expedited process applied only to aviation safety projects, aviation security projects, and airport capacity projects at congested airports.

Section 783 expanded eligibility to include:

• Terminal development projects at any commercial service airport
• All airport capacity enhancement projects — not limited to congested airports

Under § 47171, the FAA serves as the lead agency and is required to establish a coordinated review process with cooperating and participating agencies, set deadlines for their reviews, and resolve interagency disputes. This mechanism is designed to prevent the environmental review timeline from being extended by delays in other agencies' consultations.

Who Prepares the Documents

Under Order 1050.1G, the airport sponsor — or a consultant hired by the sponsor — may prepare the NEPA document. This applies to EAs and, in certain circumstances, EISs. FAA retains independent review authority and issues the decision document (FONSI, ROD).

For AIP-funded environmental studies, the FAA provides grant funding for the preparation of environmental documents. The federal share follows standard AIP cost-sharing rules: 90% federal / 10% local for most airports; 75% federal / 25% local for large and medium hubs.

Relationship Between NEPA and Capital Program Timing

NEPA review is a prerequisite to federal funding and ALP approval. No AIP or BIL grant can be issued for a project, and no ALP change can be approved, until the appropriate NEPA review is complete and a decision document has been issued.

NEPA Level	Approximate Duration (pre-2025)	Statutory Maximum (FRA 2023)	Expedited (OBBBA Fee)
CATEX	Days to months	No statutory limit	N/A
EA	6–18 months	1 year	180 days
EIS	2–5+ years	2 years	1 year

The gap between pre-2025 practice and the new statutory deadlines is notable. Whether agencies can meet the one-year EA and two-year EIS deadlines in practice — particularly for complex airport projects involving Section 106 consultation, Section 7 biological opinions, or contested noise analyses — is an operational question.

Analytical Considerations

• Order 1050.1G transition. Projects initiated before July 3, 2025 may continue under Order 1050.1F; projects initiated on or after that date must comply with 1050.1G. The boundary between "initiated" and "new" may present questions for multi-phase capital programs.
• New CATEXs and the $6 million threshold. The Section 788(a) CATEX for projects with less than $6 million in federal funds creates a pathway for smaller projects to proceed without an EA. The threshold is measured by federal funds, not total project cost.
• Fee-based expedited review. The One Big Beautiful Bill Act's 125% fee mechanism compresses an EA to 180 days and an EIS to one year. For airport sponsors with time-sensitive capital programs — where construction delays carry debt service costs on bonds already issued — this option may warrant evaluation against the fee cost.