Adoption of a Department of the Air Force Categorical Exclusion under the National Environmental Policy Act

Adoption of a Department of the Air Force Categorical Exclusion Under the National Environmental Policy Act

Dates

The categorical exclusion is adopted April 25, 2024.

Supplementary Information

I. Background

NEPA and CATEXs

The National Environmental Policy Act, as amended (42 U.S.C. 4321-4347) (NEPA), requires all Federal agencies to assess the environmental impact of their actions. Congress enacted NEPA in order to encourage productive and enjoyable harmony between humans and the environment, recognizing the profound impact of human activity and the critical importance of restoring and maintaining environmental quality to the overall welfare of humankind. 42 U.S.C. 4321, 4331. NEPA's twin aims are to ensure agencies consider the environmental effects of their proposed actions in their decision-making processes and inform and involve the public in that process. 42 U.S.C. 4331. NEPA created the Council on Environmental Quality (CEQ), which promulgated NEPA implementing regulations, 40 CFR parts 1500 through 1508 (CEQ regulations).

To comply with NEPA, agencies determine the appropriate level of review-an environmental impact statement (EIS), environmental assessment (EA), or categorical exclusion (CATEX). 42 U.S.C. 4336. If a proposed action is likely to have significant environmental effects, the agency must prepare an EIS and document its decision in a record of decision. 42 U.S.C. 4336. If the proposed action is not likely to have significant environmental effects or the effects are unknown, the agency may instead prepare an EA, which involves a more concise analysis and process than an EIS. 42 U.S.C. 4336. Following the EA, the agency may conclude the process with a finding of no significant impact if the analysis shows that the action will have no significant effects. If, however, the analysis in the EA finds that the action is likely to have significant effects which cannot be mitigated below a significant level, then an EIS is required.

Under NEPA and the CEQ regulations, a Federal agency also can establish CATEXs-categories of actions that the agency has determined normally do not significantly affect the quality of the human environment-in their agency NEPA procedures. 42 U.S.C. 4336(e)(1); 40 CFR 1501.4, 1507.3(e)(2)(ii), 1508.1(d). If an agency determines that a CATEX covers a proposed action, it then evaluates the proposed action for extraordinary circumstances in which a normally excluded action may have a significant effect. 40 CFR 1501.4(b). If no extraordinary circumstances are present or if further analysis determines that the extraordinary circumstances do not involve the potential for significant environmental impacts, the agency may apply the CATEX to the proposed action without preparing an EA or EIS. 42 U.S.C. 4336(a)(2), 40 CFR 1501.4. If the extraordinary circumstances have the potential to result in significant effects, the agency is required to prepare an EA or EIS.

Section 109 of NEPA, enacted as part of the Fiscal Responsibility Act of 2023, allows a Federal agency to "adopt" or use another agency's CATEX for a category of proposed agency actions. 42 U.S.C. 4336(c). To use another agency's CATEX under section 109, an agency must identify the relevant CATEX listed in another agency's ("establishing agency") NEPA procedures that cover its category of proposed actions or related actions; consult with the establishing agency to ensure that the proposed adoption of the CATEX to a category of actions is appropriate; identify to the public the CATEX that the agency plans to use for its proposed actions; and document adoption of the CATEX. Id. This notice documents NASA's adoption of Department of the Air Force (DAF) CATEX A2.3.34., Supersonic flying operations over land and above 30,000 feet Mean Sea Level, or over water and above 10,000 feet Mean Sea Level and more than 15 nautical miles from land, under section 109 of NEPA to use in NASA's programs and funding opportunities, including those administered by NASA's Quesst mission.

NASA's Program

NASA's Quesst mission is working with the international community to develop standards needed to open the commercial market to supersonic flight. One of the most important of these standards is for sound levels from supersonic overflight that prevent adverse impacts to populations in developed and undeveloped areas. The Quesst mission has two goals. The first is to demonstrate the viability of aerodynamic design technology that reduces the sonic boom associated with supersonic flight to a soft thump sound. The second is to collect data on the response of populations to this thump sound that will inform the development of the needed standard. The mission involves multiple supersonic flights over representative communities with diverse climates and populations in four to six discrete geographic areas of approximately 120x50 miles in the continental U.S. For each community, the Quesst mission expects to fly approximately 100 total supersonic passes over a 30-day period. The daily community overflight schedule will not exceed 3 flights per day, with one to two passes per flight, for a maximum of 6 passes per day. The flights will only occur during daytime hours ( i.e., no night flights will occur). The sound levels will approximate those of naturally occurring distant thunder and result in non-adverse effects on communities, wildlife, domesticated animals, or other natural or cultural resources. The flights will operate from military and/or joint use military-civilian airfields. Supersonic flight operations will take place at speeds up to approximately Mach 1.4 and at altitudes between 42 and 55 thousand feet over the communities. NASA will comply with all existing regulations and operating procedures in effect at the airfields and for operations within the National Airspace. Well in advance of any overflight, communities will be provided general information about the tests and the sounds that may be heard. In the event that a flight may pass over tribal lands, tribal nations will also be engaged. Survey participants selected from the community population will be asked to respond via mobile device with reactions to the supersonic thump. Ground measurement hardware, including microphones and weather equipment, will record and characterize the supersonic thump at ground level. This data will be analyzed to document the relationship between sound exposure (dose) and annoyance (response) that will be provided to the International Civil Aviation Organization's Committee on Aviation Environmental Protection (ICAO-CAEP) to inform the sound limits of a supersonic overflight noise standard.

II. Identification of the Categorical Exclusion (CATEX) DAF's Supersonic Flying Operations CATEX

The DAF's environmental impact analysis process is codified in 32 CFR part 989. The DAF's categorical exclusion process is set forth in 32 CFR 989.13 as follows:

(a) CATEXs define those categories of actions that do not individually or cumulatively have potential for significant effect on the environment and do not, therefore, require further environmental analysis in an EA or an EIS. The list of Air Force-approved CATEXs is in appendix B. Supplements to this part may not add CATEXs or expand the scope of the CATEXs in appendix B.

(b) Characteristics of categories of actions that usually do not require either an EIS or an EA (in the absence of extraordinary circumstances) include:

(1) Minimal adverse effect on environmental quality.

(2) No significant change to existing environmental conditions.

(3) No significant cumulative environmental impact.

(4) Socioeconomic effects only.

(5) Similarity to actions previously assessed and found to have no significant environmental impacts.

(c) CATEXs apply to actions in the United States and abroad. General exemptions specific to actions abroad are in 32 CFR part 187. The EPF or other decision-maker forwards requests for additional exemption determinations for actions abroad to HQ USAF/A7CI with a justification letter.

(d) Normally, any decision-making level may determine the applicability of a CATEX and need not formally record the determination on AF Form 813 or elsewhere, except as noted in the CATEX list.

(e) Application of a CATEX to an action does not eliminate the need to meet air conformity requirements (see § 989.30).

The DAF's list of specific categorical exclusions is set forth at appendix B to part 989-Categorical Exclusions. NASA identified CATEX A2.3.34., Supersonic flying operations over land and above 30,000 feet Mean Sea Level, or over water and above 10,000 feet Mean Sea Level and more than 15 nautical miles from land, as applicable and appropriate to use in NASA's programs and funding opportunities, including those administered by the NASA Quesst mission.

Proposed NASA Category of Actions

NASA intends to apply CATEX A2.3.34 to NASA's Quesst mission. NASA also intends to apply the CATEX to other similar NASA programs that meet the qualifications of the CATEX. NASA will consider each proposal to use CATEX A2.3.34 to ensure that the proposal is within the scope of the CATEX. NASA intends to apply this CATEX in a manner consistent with DAF's application.

III. Consideration of Extraordinary Circumstances

The DAF's implementing regulations in 32 CFR, part 989, appendix B describe when additional analysis may be required ( i.e., extraordinary circumstances). Circumstances may arise in which usually categorically excluded actions may have a significant environmental impact and, therefore, may generate a requirement for further environmental analysis. Examples of situations where such circumstances may be present include:

A2.2.1. Actions of greater scope or size than generally experienced for a particular category of action.

A2.2.2. Potential for degradation (even though slight) of already marginal or poor environmental conditions.

A2.2.3. Initiating a degrading influence, activity, or effect in areas not already significantly modified from their natural condition.

A2.2.4. Use of unproved technology.

A2.2.5. Use of hazardous or toxic substances that may come in contact with the surrounding environment.

A2.2.6. Presence of threatened or endangered species, archaeological remains, historical sites, or other protected resources.

A2.2.7. Proposals adversely affecting areas of critical environmental concern, such as prime or unique agricultural lands, wetlands, coastal zones, wilderness areas, floodplains, or wild and scenic river areas.

A2.2.8. Proposals with disproportionately high and adverse human health or environmental effects on minority populations or low-income populations.

When applying CATEX A2.3.34, NASA will evaluate the proposed action and ensure each circumstance prescribed both in DAF regulations (as set forth above), and in NASA's NEPA implementing regulations at 14 CFR 1216.304(c), is carefully considered and do not apply to NASA's proposed action. If an extraordinary circumstance, or circumstances, exists, NASA will determine whether the proposed action has the potential to result in a significant environmental impact before applying CATEX A2.3.34, or proceed with preparation of an EIS or EA as appropriate. NASA will comply with environmental requirements related to the proposal, including application and receipt of any necessary permits, and other applicable federal and state regulatory agency consultations and approvals which may be required.

IV. Consultation With DAF and Determination of Appropriateness

DAF and NASA consulted on the appropriateness of NASA's adoption of CATEX A2.3.34 in February 2024. DAF and NASA's consultation included a review of DAF's experience developing and applying the CATEX, as well as the types of actions for which NASA plans to use the CATEX. These NASA actions are very similar to the type of projects for which DAF has applied the CATEX and therefore the impacts of NASA projects, in this case, the Quesst mission, will be very similar to the impacts of DAF projects, which are not significant, absent the existence of extraordinary circumstances. Therefore, NASA has determined that its proposed use of the CATEX as described in this notice is appropriate.

V. Notice to the Public and Documentation of Adoption

This notice serves to identify to the public and document NASA's adoption of DAF's CATEX A2.3.34., Supersonic flying operations over land and above 30,000 feet Mean Sea Level, or over water and above 10,000 feet Mean Sea Level and more than 15 nautical miles from land. The notice identifies the types of actions to which NASA will apply the CATEX, as well as the considerations that NASA will use in determining whether an action is within the scope of the CATEX.