The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under ADDRESSES . Include “Docket No. FAA-2022-1647; Project Identifier AD-2022-01379-T” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend the proposal because of those comments.

Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to regulations.gov , including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this proposed AD.

CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this NPRM contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this NPRM, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as “PROPIN.” The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to Brett Portwood, Continued Operational Safety Technical Advisor, COS Program Management Section, Operational Safety Branch, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 817-222-5390; email: operationalsafety@faa.gov. Any commentary that the FAA receives that is not specifically designated as CBI will be placed in the public docket for this rulemaking.

The FAA issued Airworthiness Directive (AD) 2021-23-12, Amendment 39-21810 (86 FR 69984, December 9, 2021) (AD 2021-23-12), for all transport and commuter category airplanes equipped with a radio altimeter. AD 2021-23-12 was prompted by a determination that radio altimeters cannot be relied upon to perform their intended function if they experience interference from wireless broadband operations in the 3.7-3.98 GHz frequency band (5G C-Band). AD 2021-23-12 requires revising the limitations section of the existing airplane/aircraft flight manual (AFM) to incorporate limitations prohibiting certain operations requiring radio altimeter data when in the presence of 5G C-Band interference as identified by Notices to Air Missions (NOTAMs). The agency issued AD 2021-23-12 because radio altimeter anomalies that are undetected by the automation or pilot, particularly close to the ground ( e.g. , landing flare), could lead to loss of continued safe flight and landing.

Airplane Capability and Alterations: Since issuing AD 2021-23-12, the FAA has reviewed data from dozens of alternative method of compliance (AMOC) requests, demonstrating that these radio altimeters can be relied upon to perform their intended function when operating beyond a certain protection radius around 5G C-Band transmitters. The iterative AMOC process allowed the FAA to gain insight into 5G C-Band transmission impacts to runway safety zones  1 in a progressively more sophisticated manner. At first, the FAA made conservative assumptions about the potential for impact on radio altimeters from 5G C-Band transmissions and applied them to all airport environments. During the FAA's initial analyses of AMOC requests, the FAA looked to protect against 5G C-Band interference during the most critical phases of flight (takeoffs and landings) by protecting a 2-nautical mile circle around the ends of runways. After some time and an improved understanding of the C-Band signals and their effects on specific radio altimeters, the FAA was able to reduce the protected area around the ends of runways and instead define a rectangular airspace area to protect around runways. The rectangular area was further refined into a trapezoidal area, which allowed for geographically expanded 5G C-Band transmissions that would not affect radio altimeter functions within the area. The FAA is now able to assess the 5G C-Band transmissions' impact to aviation operations in a specific area, taking into account the particularities of the signal and the airport environment. This assessment process is the Signal in Space (SiS) analysis. It includes a 3-dimensional model for the runway safety zone and considers base station heights and terrain around the airport.

The AMOC process also provided data about the varying levels of interference tolerance for a majority of radio altimeters on the market, allowing the FAA to understand the overall susceptibility to interference of the existing fleet of transport airplanes. In addition, the FAA learned about the aircraft alterations that can be accomplished quickly to improve a radio altimeter's tolerance to transmissions in adjacent or nearby spectrum bands. Now that the FAA better understands the performance of specific radio altimeters and the means to make them more tolerant of transmissions in adjacent or nearby spectrum bands, the FAA is proposing the updated corrective action presented in this proposed AD.

5G Compatibility: AMOCs allowing operations otherwise prohibited by AD 2021-23-12 were based on voluntary operational mitigations undertaken by AT&T and Verizon, 5G C-Band licensees. The FAA, AT&T, and Verizon have collaborated extensively to ensure 5G C-Band radio frequency transmissions and aircraft operations can safely co-exist. In early January 2022, the FAA progressively tailored runway protection zones around airports to envelop only the airspace areas where critical phases of flight occur. The FAA has worked with AT&T and Verizon to improve the precision of the FAA's interference analyses used during the AMOC process. In turn, AT&T and Verizon coordinated their deployment around 5G C-Band mitigated airports (5G CMAs), 2 including in some cases reducing emission power around airports and committing to antenna pointing angles in the vertical plane to limit the potential for interference within the tailored runway safety zones. This collaborative work has allowed safe transport and commuter airplane operations to continue in the short term.

Update to Safety Determination: The FAA's initial determination that radio altimeters cannot be relied upon to perform their intended function if they experience interference from wireless broadband operations in the 5G C-Band remains unchanged. Therefore, this proposed AD would continue prohibiting the use of the same operations identified in the original AD (AD 2021-23-12) except for the prohibition of Required Navigation Performance with Authorization Required (RNP AR) Instrument Approach Procedures (IAP). After further analysis, the FAA has determined that 5G C-Band interference does not create an unsafe condition for an airplane conducting RNP AR IAPs because RNP AR operations do not rely on direct radio altimeter inputs to determine arrival at altitude minimums or the flight path of the airplane. Therefore, this proposed AD would no longer prohibit RNP AR IAPs.

The FAA has also gained a better understanding of 5G C-Band interference beyond its effect on the operations prohibited by AD 2021-23-12. Since 5G C-band deployment began, the FAA has solicited reports of radio altimeter anomalies from aircraft pilots and operators. 3 The FAA has received over 420 reports of radio altimeter anomalies occurring within a known location of a 5G C-Band deployment. Approximately 315 of these reports were determined to not be related to 5G C-Band interference and were resolved through normal continued operational safety procedures. But for roughly 100 of the anomaly reports occurring within NOTAM areas, the FAA has excluded other potential causes for the anomaly, but could not rule out 5G C-Band interference as the potential source of the radio altimeter anomalies. These approximately 100 incidents included various flight deck effects such as erroneous Terrain Awareness and Warning System (TAWS) warnings, erroneous Traffic Collision Avoidance System (TCAS) warnings, erroneous landing gear warnings, and the erroneous display of radio altimeter data. Although these flight deck effects are less severe than the hazards associated with low-visibility landings, the FAA is concerned that to the extent 5G C-Band operations contributed to such events, the effects will occur more frequently as telecommunication companies continue to deploy 5G C-Band services throughout the country. The FAA has assessed the cumulative effects of increasing numbers of erroneous warnings across the fleet of transport and commuter airplanes. Although they may seem minor in isolation such that some may consider them a mere nuisance, these warnings have safety implications over time. The erroneous warnings increase flightcrew workload as they try to ascertain the validity of the warning. Repeated determinations that the warning occurred in error will lead to flightcrew desensitization to warnings from these safety systems. 4 In other words, as the flightcrew becomes more desensitized to erroneous warnings, they are less likely to react to an accurate warning, negating the safety benefits of the warning altogether and likely leading to a catastrophic incident.

AD 2021-23-12 does not mitigate the hazards associated with erroneous system warnings, focusing instead on the potentially more severe hazards associated with certain low visibility operations. Additionally, AD 2021-23-12 does not address other operations near airports, such as Category I instrument landing system (ILS) or visual flight rule (VFR) approaches. Therefore, the FAA has determined that additional corrective action is required to address this unsafe condition and proposes to supersede AD 2021-23-12.

Why New Corrective Action is Needed: In addition to the hazards due to the cumulative effects of nuisance warnings described earlier, the FAA expects an increase in the number of 5G C-Band base stations around airports in the national airspace system (NAS) and expects these stations to transmit in the entire 5G C-Band frequency band (from 3.7 to 3.98 GHz). Since the FAA issued AD 2021-23-12, which focused solely on the airport environment, 5G C-Band base stations have increasingly begun transmission in other areas of the country. Whereas 5G transmissions were initially limited to 3.7 to 3.8 GHz, these transmissions have also begun to expand to 3.8 to 3.98 GHz, and the FAA expects deployment at the higher end of the frequency range to expand after July 1, 2023. 5 These higher frequencies are nearer to the spectrum allocation where radio altimeters operate (4.2 to 4.4 GHz), which means that the potential for interference to radio altimeters from in-band and spurious  6 emissions may be more likely. In addition, the FAA expects approximately 19 additional telecommunication companies in addition to AT&T and Verizon will begin transmitting in the C-Band at some point after June 2023. 7 As the 21 telecommunication companies authorized to transmit 5G C-Band continue to expand transmissions throughout the country, using NOTAMs to identify affected areas and assessing proposed AMOCs will become untenable. NOTAMs are temporary means of disseminating information until the information can be publicized by other means. Given 5G C-Band signals are not expected to be temporary and that 5G signals will cover the contiguous U.S., NOTAMs are no longer the best means of communicating the location of the 5G C-Band environment. In addition, given the information gleaned over the past year, the FAA is now able to identify the conditions under which radio altimeters can be relied on to perform their intended function in the presence of a 5G C-Band environment. Therefore, case-by-case AMOC approvals that allow performing certain operations otherwise prohibited by an AD are no longer the most efficient way for airplane operators to show that their radio altimeters perform their intended function in the 5G C-Band environment.

Determination of Airplane Radio Altimeter Tolerance Requirements: The FAA is proposing interference tolerance requirements for radio altimeters that can be used across the affected fleet. Airplanes meeting these proposed minimum performance levels would be allowed to use the prohibited operations at the airports identified by an FAA Domestic Notice  8 after July 1, 2023. Airplanes operating under 14 CFR part 121 would also be required to have a radio altimeter that meets the proposed minimum performance standards ( i.e., tolerance requirements) on or before February 1, 2024.

The FAA determined the proposed interference tolerance requirements by using the fuller understanding of specific radio altimeter capabilities the FAA gained during the AMOC process. This process revealed the radio altimeter modifications that would not require a substantial system redesign, allowing aircraft operators to readily replace radio altimeters or install filters that allowed the aircraft to operate safely in a mitigated 5G environment.

The interference tolerance requirements are represented by a power spectral density (PSD) curve. The PSD curve, as depicted in figure 1 to paragraph (g)(2) of this proposed AD, represents the height over the ground and received power from a 5G C-Band emitter, at or below which the radio altimeter is expected to function reliably, measured in decibels per megahertz. These measurements are limited to the 5G CMAs that will be listed in an FAA Domestic Notice. For purposes of this proposed AD, a “radio altimeter tolerant airplane” (also known within industry as a Group 4 airplane) is one for which the radio altimeter, as installed, demonstrates tolerance to radio altimeter interference at or above PSD curve threshold specified in figure 1 to paragraph (g)(2) of this proposed AD. A radio altimeter tolerant airplane also demonstrates tolerance to a spurious emission level of −48 dBm/MHz in the 4200-4400 MHz radio altimeter band. For purposes of this proposed AD, a “non-radio altimeter tolerant airplane” (also known in industry as a Group 1, 2, or 3 airplane) is one for which the radio altimeter, as installed, does not demonstrate those tolerances. Some radio altimeters may already demonstrate tolerance to the 5G C-Band emissions without modification. Some may need to install filters between the radio altimeter and antenna to increase a radio altimeter's tolerance. For others, the addition of a filter will not be sufficient to address interference susceptibility; therefore, the radio altimeter will need to be replaced with an upgraded radio altimeter. The FAA has determined that radio altimeter tolerant airplanes will not experience the unsafe condition at any airport identified by the FAA as a 5G CMA in an FAA Domestic Notice.

Areas of Operation: Over the past year, the FAA and the aviation industry, using data voluntarily provided by AT&T and Verizon, have identified maximum power levels for 5G C-Band transmissions that would permit safe aircraft operations. These power levels were identified using a SiS analysis that considers factors specific to an airport. That is, the SiS analysis considers specific 5G C-Band base station data to predict the 5G signal characteristics in the runway safety zone. The base station data includes 5G C-Band tower or antenna locations, fundamental transmission power levels, and antenna height. Using this analysis, the FAA has found that airplanes meeting the proposed standards as represented by the PSD curve can safely perform the prohibited operations specified in this proposed AD at 5G CMAs. These operations are safe for radio altimeter tolerant airplanes to perform at these airports as long as telecommunication companies transmit at parameters under the current voluntary agreements with the FAA and FCC.

Compatibility with 5G C-Band Providers: The FAA has determined that any 5G C-Band provider that maintains the mitigated actions will not have an effect on the safety of transport and commuter airplanes with radio altimeters that meet the interference tolerance requirements at 5G CMAs. The FAA will assess the effects of any changes to transmission parameters at 5G CMAs to determine whether they would result in a hazard to air navigation. If the transmission changes negatively affect the safe operation of a radio altimeter tolerant airplane at that airport, the FAA will remove that airport from the 5G CMAs list.

Therefore, the FAA has determined that an unsafe condition exists when performing certain operations in the presence of 5G C-Band transmissions affecting the proper function of radio altimeters. For that reason, operators would be required to revise their existing AFM to prohibit these operations unless operating a radio altimeter tolerant airplane at a 5G CMA. This proposed requirement would take effect on July 1, 2023.

In addition, the FAA proposes to prohibit operations under part 121 in the U.S. after February 1, 2024, unless such operations are conducted with a radio altimeter tolerant airplane. As explained earlier, the FAA expects erroneous system warnings due to a malfunctioning radio altimeter to lead to flightcrew becoming desensitized to system warnings. Such desensitization negates the safety benefits of the warning itself and can lead to a catastrophic event. To minimize the number of erroneous system messages and the unsafe condition they produce, the FAA is proposing to require all airplanes operating under part 121 meet the PSD performance curve to operate in the contiguous U.S. after February 1, 2024. This is the date the FAA has determined to be as soon as reasonably practical, consistent with FAA policy. 9 Non-radio altimeter tolerant airplanes can operate under part 121 subject to the revised AFM limitations until February 1, 2024, without meeting the radio altimeter performance requirements proposed in this AD. If this AD is finalized as proposed, after February 1, 2024, airplanes operating under part 121 must meet the radio altimeter tolerant requirements specified in figure 1 to paragraph (g)(2) of this proposed AD.

The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design.

This proposed AD would maintain the requirements of AD 2021-23-12, except for the limitation pertaining to RNP AR IAPs by requiring, before further flight, revising the existing AFM to incorporate limitations prohibiting the following operations in the presence of 5G C-Band wireless broadband interference as identified by NOTAM (NOTAMs will be issued to state the specific airports where the radio altimeter is unreliable due to the presence of 5G C-Band wireless broadband interference). Alternatively, operators may incorporate the AFM revision required by paragraph (g) of AD 2021-23-12.

On or before June 30, 2023, this proposed AD would also require revising the existing AFM to incorporate limitations prohibiting these same operations at all airports for non-radio altimeter tolerant airplanes. For radio altimeter tolerant airplanes, the prohibited operations would be allowed at 5G CMAs as identified in an FAA Domestic Notice.

On or before February 1, 2024, this proposed AD would require that airplanes operating under Part 121 be modified from a non-radio altimeter tolerant airplane to a radio altimeter tolerant airplane.

The FAA considers that this AD, if adopted as proposed, would be an interim action. Once the Technical Standard Order (TSO) standard for radio altimeters is established, which will follow the existing international technical consensus on the establishment of the minimum operational performance standards (MOPS), the FAA anticipates that the MOPS will be incorporated into the TSO. The FAA also anticipates that aircraft incorporating equipment approved under the new Radio Altimeter TSO will be able to operate in both 5G CMAs and non-5G CMAs with no 5G C-Band-related AFM limitations. Once a new radio altimeter TSO is developed, approved, and available, the FAA might consider additional rulemaking.

The FAA is requesting comments on this evaluation of costs and benefits for the proposed airworthiness directive. If adopted as proposed, this AD would affect approximately 7,993 airplanes of U.S. registry, all of which would require two AFM revisions. In Special Airworthiness Information Bulletin AIR-21-18R2, the FAA requested radio altimeter retrofit plans, timelines, and completion information from the aviation industry. The FAA did not receive comprehensive data, but based on the limited information the agency did receive, the FAA extrapolated impacts across industry. Based on that information, the FAA roughly estimates that almost 7,000 airplanes on the U.S. registry are already equipped or are being retrofitted to address radio altimeter interference tolerance before publication of this AD, or are not operated under 14 CFR part 121, and thus would only require AFM revisions to comply with this AD as proposed. Based on information received, some operators will comply with the proposed modification by replacing the radio altimeter and others by installing an externally mounted filter. The FAA estimates that approximately 180 airplanes would require radio altimeter replacement and 820 airplanes would require addition of radio altimeter filters to comply with the proposed modification requirement. As such, the FAA estimates the following costs to comply with this proposed AD, for a total cost of compliance of up to $26,049,810:

The benefits of the proposed AD would include the value of reducing aviation accident risks that are mitigated by TAWS, TCAS, and airborne windshear warning and flight guidance systems (windshear systems), all of which rely on proper performance of radio altimeters to perform their intended function. TAWS, TCAS, and windshear systems are examples of safety-enhancing systems required for operation under 14 CFR part 121. The FAA required these systems to address hazards which have caused accidents and fatalities during commercial air transportation in the United States. This proposed AD would maintain the same level of safety afforded by these and other safety systems before the use of the C-Band by 5G broadband networks. This proposed AD would also minimize erroneous system messages and the unsafe condition they produce.

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

The FAA is issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: General requirements. Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

The FAA has determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that the proposed regulation:

(1) Is not a “significant regulatory action” under Executive Order 12866, and

(2) Would not affect intrastate aviation in Alaska.

The Regulatory Flexibility Act (RFA) of 1980, Public Law 96-354, 94 Stat. 1164 (5 U.S.C. 601-612), as amended by the Small Business Regulatory Enforcement Fairness Act of 1996 (Pub. L. 104-121, 110 Stat. 857, Mar. 29, 1996) and the Small Business Jobs Act of 2010 (Pub. L. 111-240, 124 Stat. 2504, Sept. 27, 2010), requires Federal agencies to consider the effects of the regulatory action on small business and other small entities and to minimize any significant economic impact. The term “small entities” comprises small businesses and not-for-profit organizations that are independently owned and operated and are not dominant in their fields, and governmental jurisdictions with populations of less than 50,000.

The FAA is publishing this Initial Regulatory Flexibility Analysis (IRFA) to aid the public in commenting on the potential impacts to small entities from this proposal. The FAA invites interested parties to submit data and information regarding the potential economic impact that would result from the proposal. The FAA will consider comments when making a determination or when completing a Final Regulatory Flexibility Assessment. An IRFA contains the following:

(1) A description of the reasons why the action by the agency is being considered;

(2) A succinct statement of the objective of, and legal basis for, the proposed rule;

(3) A description of and, where feasible, an estimate of the number of small entities to which the proposed rule will apply;

(4) A description of the projected reporting, recordkeeping, and other compliance requirements of the proposed rule, including an estimate of the classes of small entities which will be subject to the requirement and the type of professional skills necessary for preparation of the report or record;

(5) An identification, to the extent practicable, of all relevant Federal rules that may duplicate, overlap, or conflict with the proposed rule; and

(6) A description of any significant alternatives to the proposed rule which accomplish the stated objectives of applicable statutes and which minimize any significant economic impact of the proposed rule on small entities.

AD 2021-23-12 requires revising the limitations section of the existing AFM to incorporate limitations prohibiting certain operations requiring radio altimeter data when in the presence of 5G C-Band interference as identified by NOTAMs. Since the FAA issued AD 2021-23-12, the FAA determined that more restrictive limitations are needed due to the continued deployment of new 5G C-Band base stations whose signals are expected to cover most of the contiguous United States at transmission frequencies between 3.7-3.98 GHz. This proposed AD would address the unsafe condition resulting from the continued deployment of 5G C-Band transmissions and their interference to radio altimeters.

This proposed AD would require revising the limitations section of the existing AFM to incorporate limitations prohibiting certain operations requiring radio altimeter data, due to the presence of 5G C-Band interference. This proposed AD would also require modifying certain airplanes to allow safe operations in the United States 5G C-Band-radio frequency environment.

The FAA used the definition of small entities in the RFA for this analysis. The RFA defines small entities as small businesses, small governmental jurisdictions, or small organizations. In 5 U.S.C. 601(3), the RFA defines “small business” to have the same meaning as “small business concern” under section 3 of the Small Business Act. The Small Business Act authorizes the Small Business Administration (SBA) to define “small business” by issuing regulations.

The SBA established size standards for various types of economic activities, or industries, under the North American Industry Classification System (NAICS). 10 These size standards generally define small businesses based on the number of employees or annual receipts. The following table shows the SBA size standards for certificate holders as an example. Note that the SBA definition of a small business applies to the parent company and all affiliates as a single entity.

Certificate holders affected by the proposed AD are those authorized to conduct operations under 14 CFR part 121. To identify small entities, the FAA reviewed readily available data sources ( e.g., company websites) and data available to the FAA through its certificate oversight functions to determine whether the certificate holder meets the applicable size standard. The following table provides a summary of the estimated number of small entities to which this proposed AD would apply.

No new recordkeeping or reporting requirements are associated with the proposed AD. Small entity compliance with the proposed AD would entail incorporation of AFM revisions at an approximate cost of $170 per airplane. As discussed previously, the FAA estimates that the majority of airplanes operated by small entities will already be equipped in a manner that complies with the proposed requirements of this AD. Given the relatively small aircraft fleet sizes for small entity airlines, the FAA anticipates that a small number of airplanes would need to have radio altimeter filters installed (at an approximate cost of $5,020 per filter), and a smaller number of airplanes will require a radio altimeter replacement (at an approximate cost of up to $80,000 per airplane). These costs represent a small percentage of the overall cost of owning and operating a transport category airplane, and to the extent that small entities provide more unique services or serve markets with less competition, these entities might be able to pass on these small incremental costs of AD compliance in the form of price increases.

There are no relevant Federal rules that may duplicate, overlap, or conflict with the proposed AD.

This AD specifies the only feasible alternatives identified for mitigating the unsafe condition. If a less burdensome method for mitigating the unsafe condition is identified, the FAA will consider proposed alternative methods of compliance, if requested, using the procedures found in 14 CFR 39.19.

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

On January 1, 2021, the William M. (Mac) Thornberry National Defense Authorization Act for Fiscal Year 2021 (Pub. L. 116-283) (Authorization Act) was enacted. Section 8343 (134 Stat. 4710) calls for the Coast Guard to conduct a two-year pilot program to establish and implement a process to establish safety zones to address special activities in the U.S. Exclusive Economic Zone (EEZ). 1 These special activities include space activities  2 carried out by United States (U.S.) citizens. Terms used to describe space activities, including launch, reentry site, and reentry vehicle, are defined in 51 U.S.C. 50902, and in this document.

The Coast Guard has long monitored space activities impacting the maritime domain and taken actions to ensure the safety of vessels and the public as needed during space launch  3 operations. In conducting this activity, the Coast Guard engages with other government agencies, including the Federal Aviation Administration (FAA) and National Aeronautics and Space Administration (NASA), and private space operators, including Space Exploration Technologies Corporation (SpaceX). This engagement is necessary to ensure statutory and regulatory obligations are met to ensure the safety of launch operations and waterway users.

During this engagement, the Coast Guard was informed of space reentry vehicles and recovery operations in the U.S. EEZ. Section 50902 of 51 U.S.C. defines “reentry vehicle” as a vehicle designed to return from Earth orbit or outer space to Earth, or a reusable launch vehicle designed to return from Earth orbit or outer space to Earth, substantially intact. SpaceX, a U.S. company, has identified three reentry sites  4 within the U.S. EEZ of the Coast Guard District Eight area of responsibility (AOR) expected to be used for the splashdown  5 and recovery of reentry vehicles. All of these sites are located in the Gulf of Mexico off the coast of Florida (FL).

On May 4, 2022, we published a temporary final rule in the Federal Register (87 FR 26273) for two anticipated reentry vehicle recovery missions within the Coast Guard District Eight AOR offshore of Panama City, Pensacola, and Tallahassee, FL from April 17, 2022 through May 15, 2022. Based on the date the Coast Guard was informed of the reentry, and the immediate need to establish the safety zone, the Coast Guard did not have sufficient time to publish a notice of proposed rulemaking (NPRM) for that rule. The Coast Guard additionally published recovery mission temporary final rules for the periods from August 22, 2022 through September 30, 2022 (87 FR 51253) and October 12, 2022 through November 10, 2022 (87 FR 61508).

The purpose of this rulemaking is to ensure the protection of vessels and waterway users in the U.S. EEZ from the potential hazards created by reentry vehicle splashdowns and recovery operations, and the safe recovery of reentry vehicles and personnel involved in reentry services. 6 The Coast Guard is proposing this rulemaking under authority of section 8343 of the Authorization Act.

The Coast Guard is proposing to establish three temporary safety zones in the U.S. EEZ for the safe reentry vehicle splashdown and recovery of reentry vehicles launched by SpaceX in support of NASA missions through the remainder of the pilot period, which ends on February 4, 2024.

The proposed temporary safety zones are located within the Coast Guard District Eight AOR offshore of Panama City, Pensacola, and Tallahassee, FL in the Gulf of Mexico. The proposed rule would prohibit U.S.-flagged vessels from entering any of the safety zones unless authorized by the Commanding Officer of Coast Guard Sector Mobile or a designated representative. Because the safety zones are within the U.S. EEZ, only U.S.-flagged vessels would be subject to enforcement. However, all foreign-flagged vessels would be encouraged to remain outside the safety zones.

The three proposed temporary safety zones are located off the coast of FL in the Gulf of Mexico in the following areas: (1) Approximately 30 NM southwest from Pensacola; (2) 26 NM southwest from Panama City; and 40 NM south of Tallahassee. All three safety zones have an approximate area of 100 square miles and are in the shape of a square.

The coordinates for the safety zones are based on the furthest north, east, south, and west points of the reentry vehicles splashdown and are determined from data and modeling by SpaceX and NASA. The coordinates take into account the trajectories of the reentry vehicles coming out of orbit, the potential risk to the public, and the proximity to medical facilities that meet NASA requirements. The specific coordinates for the three temporary safety zones are presented in the regulatory text at the end of this document.

To the extent feasible, the Sector Commander or a designated representative would inform the public of the activation of the three temporary safety zones by Notice of Enforcement (NOE) published in the Federal Register at least two days before the reentry vehicle splashdown. The NOE would identify the approximate date(s) during which a reentry vehicle splashdown and recovery operations would occur.

To the extent possible, twenty-four hours before a reentry vehicle splashdown and recovery operations, the Sector Commander or designated representative would inform the public that only one of the three safety zones would remain activated (subject to enforcement) until announced by Broadcast Notice to Mariners (BNM) on VHF-FM channel 16, and/or Marine Safety Information Bulletin (MSIB) (as appropriate) that the safety zone is no longer subject to enforcement. The specific temporary safety zone to be enforced would be based on varying mission and environmental factors, including atmospheric conditions, sea state, weather, and orbital calculations.

The MSIB would include the geographic coordinates of the activated safety zone, a map identifying the location of the activated safety zone, and information related to potential hazards associated with a reentry vehicle splashdown and recovery operations associated with space activities, including marine environmental and public health hazards, such the release of hydrazine and other potential oil or hazardous substances.

When the safety zone is activated, the Sector Commander or a designated representative would be able to restrict U.S.-flagged vessel movement including but not limited to transiting, anchoring, or mooring within the safety zone to protect vessels from hazards associated with space activities. The activated safety zone would ensure the protection of vessels and waterway users from the potential hazards created by reentry vehicle splashdowns and recovery operations. This includes protection during the recovery of a reentry vehicle, and the protection of personnel involved in reentry services and space support vessels. 7

After a reentry vehicle splashdown, the Sector Commander or a designated representative would grant general permission to come no closer than 3 NM within the activated safety zone from any reentry vehicle or space support vessel engaged in the recovery operations. The recovery operations are expected to last approximately one hour. That should allow for sufficient time to let any potential toxic materials clear the reentry vehicle, recovery of the reentry vehicle by the space support vessel, and address any potential medical evacuations for any personnel involved in reentry services that were onboard the reentry vehicle.

Once a reentry vehicle and any personnel involved in reentry services are removed from the water and secured onboard a space support vessel, the Sector Commander or designated representative would issue a BNM on VHF-FM channel 16 announcing the activated safety zone is no longer subject to enforcement. A photograph of a reentry vehicle and space support vessel expected to use the reentry sites are available in the docket.

We developed this proposed rule after considering numerous statutes and Executive orders related to rulemaking. Below we summarize our analyses based on a number of these statutes and Executive orders, and we discuss First Amendment rights of protestors.

Executive Orders 12866 and 13563 direct agencies to assess the costs and benefits of available regulatory alternatives and, if regulation is necessary, to select regulatory approaches that maximize net benefits. This NPRM has not been designated a “significant regulatory action,” under Executive Order 12866. Accordingly, the NPRM has not been reviewed by the Office of Management and Budget (OMB).

This regulatory action determination is based on the size, location, duration, and scope of the temporary safety zones. The temporary safety zones are limited in size and location to only those areas where reentry vehicles splashdown and recovery operations occur. The safety zones are limited in scope, as vessel traffic would be able to safely transit around the activated safety zone which will only impact a small part of the U.S. EEZ within the Gulf of Mexico. The proposed rule involves the establishment of three temporary safety zones which would be activated two days before a reentry vehicle splashdown and recovery operations. Twenty-four hours before a reentry vehicle splashdown, one of the three temporary safety zones would remain active. After a reentry vehicle splashdown, general permission would be granted to come no closer than 3 NM within the activated safety zone. There is a danger associated with fumes from the reentry vehicle after it has splashed down. Once a reentry vehicle and any personnel involved in reentry services are removed from the water and secured onboard a space support vessel, the activated safety zone would no longer be subject to enforcement. The activated safety zone would ensure the protection of vessels and waterway users from the potential hazards created by a reentry vehicle splashdown and recovery operations and the recovery of a reentry vehicle, personnel involved in reentry services, and space support vessel.

The Regulatory Flexibility Act of 1980, 5 U.S.C. 601-612, as amended, requires Federal agencies to consider the potential impact of regulations on small entities during rulemaking. The term “small entities” comprises small businesses, not-for-profit organizations that are independently owned and operated and are not dominant in their fields, and governmental jurisdictions with populations of less than 50,000. The Coast Guard certifies under 5 U.S.C. 605(b) that this proposed rule would not have a significant economic impact on a substantial number of small entities.

The safety zones are only expected to last a few hours from reentry vehicle splashdown to recovery. Vessels will be able to transit around the activated safety zone location during these recoveries. We do not anticipate any significant economic impact resulting from activation of the safety zones.

If you think that your business, organization, or governmental jurisdiction qualifies as a small entity, and that this proposed rule would have a significant economic impact on it, please submit a comment (see ADDRESSES ) explaining why you think it qualifies and how and to what degree this rule would economically affect it.

Under section 213(a) of the Small Business Regulatory Enforcement Fairness Act of 1996 (Pub. L. 104-121), we want to assist small entities in understanding this proposed rule. If the proposed rule would affect your small business, organization, or governmental jurisdiction and you have questions concerning its provisions or options for compliance, please call or email the person listed in the FOR FURTHER INFORMATION CONTACT section. The Coast Guard will not retaliate against small entities that question or complain about this proposed rule or any policy or action of the Coast Guard.

This proposed rule would not call for a new collection of information under the Paperwork Reduction Act of 1995 (44 U.S.C. 3501-3520).

A rule has implications for federalism under Executive Order 13132 (Federalism), if it has a substantial direct effect on the States, on the relationship between the National Government and the States, or on the distribution of power and responsibilities among the various levels of government. We have analyzed this proposed rule under that Order and have determined that it is consistent with the fundamental federalism principles and preemption requirements described in Executive Order 13132.

Also, this proposed rule does not have tribal implications under Executive Order 13175 (Consultation and Coordination with Indian Tribal Governments) because it would not have a substantial direct effect on one or more Indian tribes, on the relationship between the Federal Government and Indian tribes, or on the distribution of power and responsibilities between the Federal Government and Indian tribes. If you believe this proposed rule has implications for federalism or Indian tribes, please call or email the person listed in the FOR FURTHER INFORMATION CONTACT section.

The Unfunded Mandates Reform Act of 1995 (2 U.S.C. 1531-1538) requires Federal agencies to assess the effects of their discretionary regulatory actions. In particular, the Act addresses actions that may result in the expenditure by a State, local, or tribal government, in the aggregate, or by the private sector of $100,000,000 (adjusted for inflation) or more in any one year. Though this proposed rule would not result in such an expenditure, we do discuss the potential effects of this proposed rule elsewhere in this preamble.

We have analyzed this proposed rule under Department of Homeland Security Directive 023-01, Rev. 1, associated implementing instructions, and Environmental Planning COMDTINST 5090.1 (series), which guide the Coast Guard in complying with the National Environmental Policy Act of 1969 (42 U.S.C. 4321-4370f), and have made a preliminary determination that this action is one of a category of actions that do not individually or cumulatively have a significant effect on the human environment. This proposed rule involves the establishment of three temporary safety zones which would be activated two days before a reentry vehicle splashdown and recovery operations. Twenty-four hours before a reentry vehicle splashdown, one of the three temporary safety zones would remain active. After a reentry vehicle splashdown, general permission would be granted to come no closer than 3 NM within the activated safety zone. Once a reentry vehicle and any personnel involved in reentry services are removed from the water and secured onboard a space support vessel, the activated safety zone would no longer be subject to enforcement. Normally such actions are categorically excluded from further review under paragraph L60(a) of Appendix A, Table 1 of DHS Instruction Manual 023-01-001-01, Rev. 1. A preliminary Record of Environmental Consideration supporting this determination is available in the docket. For instructions on locating the docket, see the ADDRESSES section of this preamble. We seek any comments or information that may lead to the discovery of a significant environmental impact from this proposed rule.

The Coast Guard respects the First Amendment rights of protesters. Protesters are asked to call or email the person listed in the FOR FURTHER INFORMATION CONTACT section to coordinate protest activities so that your message can be received without jeopardizing the safety or security of people, places, or vessels.

We view public participation as essential to effective rulemaking, and will consider all comments and material received during the comment period. Your comment can help shape the outcome of this rulemaking. If you submit a comment, please include the docket number for this rulemaking, indicate the specific section of this document to which each comment applies, and provide a reason for each suggestion or recommendation.

Submitting comments. We encourage you to submit comments through the Federal Decision Making Portal at https://www.regulations.gov. To do so, go to https://www.regulations.gov, type USCG-2022-0995 in the search box and click “Search.” Next, look for this document in the Search Results column, and click on it. Then click on the Comment option. If you cannot submit your material by using https://www.regulations.gov, call or email the person in the FOR FURTHER INFORMATION CONTACT section of this proposed rule for alternate instructions.

Viewing material in docket. To view documents mentioned in this proposed rule as being available in the docket, find the docket as described in the previous paragraph, and then select “Supporting & Related Material” in the Document Type column. Public comments will also be placed in our online docket and can be viewed by following instructions on the https://www.regulations.gov Frequently Asked Questions web page. We review all comments received, but we will only post comments that address the topic of the proposed rule. We may choose not to post off-topic, inappropriate, or duplicate comments that we receive.

Personal information. We accept anonymous comments. Comments we post to https://www.regulations.gov will include any personal information you have provided. For more about privacy and submissions to the docket in response to this document, see DHS's eRulemaking System of Records notice (85 FR 14226, March 11, 2020).

For the reasons discussed in the preamble, the Coast Guard is proposing to amend 33 CFR part 165 as follows:

Under Clean Air Act (CAA or Act) section 110(a)(2)(D)(i)(I), also called the good neighbor provision, states are required to address the interstate transport of air pollution. Specifically, the good neighbor provision requires that each state's implementation plan contain adequate provisions to prohibit air pollutant emissions from within the state that will significantly contribute to nonattainment of the national ambient air quality standards (NAAQS), or that will interfere with maintenance of the NAAQS, in any other state.

On October 27, 1998 (63 FR 57356), EPA finalized the “Finding of Significant Contribution and Rulemaking for Certain States in the Ozone Transport Assessment Group Region for Purposes of Reducing Regional Transport of Ozone” (NO X SIP Call). The NO X SIP Call required eastern states, including Tennessee, to submit SIPs limiting emissions of ozone season NO X by implementing statewide emissions budgets. The NO X SIP Call addressed the good neighbor provision for the 1979 ozone NAAQS and was designed to mitigate the impact of transported NO X emissions, one of the precursors of ozone. 1 EPA developed the NO X Budget Trading Program, an allowance trading program that states could adopt to meet their obligations under the NO X SIP Call. This trading program allowed the following sources to participate in a regional cap and trade program: generally, electricity generating units (EGUs) with capacity greater than 25 megawatts (MW); and large industrial non-EGUs, such as boilers and combustion turbines, with a rated heat input greater than 250 million British thermal units per hour (MMBtu/hr). The NO X SIP Call also identified potential reductions from cement kilns and stationary internal combustion engines.

To comply with the NO X SIP Call requirements, in 2000 and 2001, TDEC submitted a revision to add new rule sections to the SIP-approved version of Chapter 1200-3-27, Nitrogen Oxides, of the Tennessee Rules. EPA approved the revision as compliant with Phase I of the NO X SIP Call in 2004. See 69 FR 3015 (January 22, 2004). The approved revision required EGUs and large non-EGUs in the State to participate in the NO X Budget Trading Program beginning in 2004. In 2005, Tennessee submitted, and EPA approved, a SIP revision to address additional emissions reductions required for the NO X SIP Call under Phase II. See 70 FR 76408 (December 27, 2005).

In 2005, EPA published the Clean Air Interstate Rule (CAIR), which required several eastern states, including Tennessee, to submit SIPs that prohibited emissions consistent with revised ozone season NO X budgets (as well as annual budgets for NO X and sulfur dioxide). See 70 FR 25162 (May 12, 2005); see also 71 FR 25328 (April 28, 2006). CAIR addressed the good neighbor provision for the 1997 ozone NAAQS and 1997 fine particulate matter (PM 2.5 ) NAAQS and was designed to mitigate the impact of transported NO X emissions with respect to ozone and PM 2.5 . CAIR established several trading programs that EPA implemented through federal implementation plans (FIPs) for EGUs greater than 25 MW in each affected state, but not large non-EGUs; states could submit SIPs to replace the FIPs that achieved the required emission reductions from EGUs and/or other types of sources. 2 When the CAIR trading program for ozone season NO X was implemented beginning in 2009, EPA discontinued administration of the NO X Budget Trading Program; however, the requirements of the NO X SIP Call continued to apply.

On November 25, 2009 (74 FR 61535), EPA approved revisions to Tennessee's SIP that incorporated requirements for CAIR. Consistent with CAIR's requirements, EPA approved a SIP revision in which Tennessee regulations: (1) terminated its NO X Budget Trading Program requirements, and (2) incorporated CAIR annual and ozone season NO X state trading programs. See 74 FR 61535. Participation of EGUs in the CAIR ozone season NO X trading program addressed the State's obligation under the NO X SIP Call for those units, and Tennessee also chose to require non-EGUs subject to the NO X SIP Call to participate in the same CAIR trading program. In this manner, Tennessee's CAIR rules incorporated into the SIP addressed the State's obligations under the NO X SIP Call with respect to both EGUs and non-EGUs.

The United States Court of Appeals for the District of Columbia Circuit (D.C. Circuit) initially vacated CAIR in 2008, but ultimately remanded the rule to EPA without vacatur to preserve the environmental benefits provided by CAIR. See North Carolina v. EPA, 531 F.3d 896, modified on rehearing, 550 F.3d 1176 (D.C. Cir. 2008). The ruling allowed CAIR to remain in effect temporarily until a replacement rule consistent with the court's opinion was developed. While EPA worked on developing a replacement rule, the CAIR program continued to be implemented with the NO X annual and ozone season trading programs beginning in 2009 and the SO 2 annual trading program beginning in 2010.

Following the D.C. Circuit's remand of CAIR, EPA promulgated the Cross- State Air Pollution Rule (CSAPR) to replace CAIR and address good neighbor obligations for the 1997 ozone NAAQS, the 1997 PM 2.5 NAAQS, and the 2006 PM 2.5 NAAQS. See 76 FR 48208 (August 8, 2011). Through FIPs, CSAPR required EGUs in eastern states, including Tennessee, to meet annual and ozone season NO X emission budgets and annual SO 2 emission budgets implemented through new trading programs. Implementation of CSAPR began on January 1, 2015. 3 CSAPR also contained provisions that would sunset CAIR-related obligations on a schedule coordinated with the implementation of the CSAPR compliance requirements. Participation by a state's EGUs in the CSAPR trading program for ozone season NO X generally addressed the state's obligation under the NO X SIP Call for EGUs. CSAPR did not initially contain provisions allowing states to incorporate large non-EGUs into that trading program to meet the requirements of the NO X SIP Call for non-EGUs. EPA also stopped administering CAIR trading programs with respect to emissions occurring after December 31, 2014. 4

Even though the CAIR programs have not been implemented in Tennessee since 2014, ozone season NO X emissions have remained well below the NO X SIP Call budget levels. Through a letter to EPA dated February 27, 2017, 5 Tennessee provided a SIP revision to incorporate a new provision—TACPR 1200-03-27-.12, “NO X SIP Call Requirements for Stationary Boilers and Combustion Turbines” (TN 2017 NO X SIP Call Rule)—into the SIP. The TN 2017 NO X SIP Call Rule established a state control program for sources that are subject to the NO X SIP Call, but not covered under CSAPR or the CSAPR Update (background regarding the CSAPR Update is provided later in this document). The TN 2017 NO X SIP Call Rule contains several subsections that together comprise a non-EGU control program under which Tennessee will allocate a specified budget of allowances to affected sources. Subsequently, on May 11, 2018, and October 11, 2018, Tennessee submitted letters requesting conditional approval  6 of the TN 2017 NO X SIP Call Rule and committing to provide a SIP revision to EPA by December 31, 2019, to address a deficiency by revising the definition of “affected unit” to remove the unqualified exclusion for any unit that serves a generator that produces power for sale. Based on the State's commitment to submit a SIP revision addressing the identified deficiency, EPA conditionally approved the February 27, 2017, submission. In the same action, EPA approved removal of the State's NO X Budget Trading Program and CAIR rules from Tennessee's SIP. See 84 FR 7998 (March 6, 2019).

Tennessee submitted a SIP revision on December 19, 2019, which revised Tennessee Air Pollution Control Regulation (TAPCR) 1200-03-27-.12, “NO X SIP Call Requirements for Stationary Boilers and Combustion Turbines” to correct the definition of “affected unit” and to clarify requirements related to stationary boilers and combustion turbines. On March 2, 2021 (86 FR 12092), EPA published a final rule which corrected the definition of “affected unit” and clarified requirements related to stationary boilers and combustion turbines. EPA also converted the conditional approval of the TN 2017 NO X SIP Call Rule to a full approval. See EPA's March 2, 2021 (86 FR 12092), final rule for further detail on these changes and EPA's rationale for approving them.

After litigation that reached the Supreme Court, the D.C. Circuit generally upheld CSAPR but remanded several state budgets to EPA for reconsideration. EME Homer City Generation, L.P. v. EPA, 795 F.3d 118, 129-30 (D.C. Cir. 2015). EPA addressed the remanded ozone season NO X budgets in the Cross-State Air Pollution Rule Update for the 2008 Ozone NAAQS (CSAPR Update), which also partially addressed eastern states' good neighbor obligations for the 2008 ozone NAAQS. See 81 FR 74504 (October 26, 2016). The air quality modeling for the CSAPR Update demonstrated that Tennessee contributes significantly to nonattainment and/or interferes with maintenance of the 2008 ozone NAAQS in other states. The CSAPR Update reestablished an option for most states to meet their ongoing obligations for non-EGUs under the NO X SIP Call by including the units in the CSAPR Update trading program.

The CSAPR Update trading program replaced the original CSAPR trading program for ozone season NO X for most covered states. Tennessee's EGUs participate in the CSAPR Update trading program, which generally also addresses the State's obligations under the NO X SIP Call for EGUs. However, Tennessee elected not to include its large non-EGUs in the CSAPR Update ozone season trading program. Because Tennessee's large non-EGUs do not participate in any CSAPR or CSAPR Update trading program for ozone season NO X emissions, the NO X SIP Call regulations at 40 CFR 51.121(r)(2), as well as anti-backsliding provisions at 40 CFR 51.905(f) and 40 CFR 51.1105(e), require these non-EGUs to maintain compliance with NO X SIP Call requirements in some other way.

Under 40 CFR 51.121(f)(2) of the NO X SIP Call regulations, where a state's implementation plan contains control measures for EGUs and large non-EGU boilers and combustion turbines, the SIP must contain enforceable limits on the ozone season NO X mass emissions from these sources. In addition, under 40 CFR 51.121(i)(4) of the NO X SIP Call regulations as originally promulgated, the SIP also had to require these sources to monitor emissions according to the provisions of 40 CFR part 75, which generally entails the use of continuous emission monitoring systems. Tennessee triggered these requirements by including control measures in its SIP for these types of sources, and the requirements have remained in effect despite the discontinuation of the NO X Budget Trading Program after the 2008 ozone season.

On March 8, 2019, EPA revised some of the regulations that were originally promulgated in 1998 to implement the NO X SIP Call. 7 The revision gave states covered by the NO X SIP Call greater flexibility concerning the form of the NO X emissions monitoring requirements that the states must include in their SIPs for certain emissions sources. The revision amended 40 CFR 51.121(i)(4) to make part 75 monitoring, recordkeeping, and reporting optional, such that SIPs may establish alternative monitoring requirements for NO X SIP Call budget units that meet the general requirements of 40 CFR 51.121(f)(1) and 51.121(i)(1). Under the updated provision, a state's implementation plan still needs to include some form of emissions monitoring requirements for these types of sources, consistent with the NO X SIP Call's general enforceability and monitoring requirements at 40 CFR 51.121(f)(1) and 51.121(i)(1), respectively, but states are no longer required to satisfy these general NO X SIP Call requirements specifically through the adoption of 40 CFR part 75 monitoring requirements.

Following EPA's March 8, 2019, revision to the NO X SIP Call requirements, Eastman petitioned TDEC to adopt revised permit conditions applicable to its Kingsport, Tennessee facility with an alternative monitoring option for this large non-EGU, along with corresponding revised recordkeeping and reporting conditions. This petition resulted in the issuance of the permit for Eastman included as part of TDEC's SIP submittal. The changes allow Eastman to address the NO X SIP Call's requirements for enforceable limits on ozone season NO X mass emissions through alternative monitoring and reporting methodologies. The August 11, 2021, source-specific SIP revision submitted by TDEC contains the permit provisions that TDEC modified to specifically address the alternative monitoring provisions allowed under the NO X SIP Call and requests conditional approval of those provisions into the SIP. The contents of the submittal and EPA's analysis is further discussed in Sections II and III.

TDEC's August 11, 2021, letter requests that EPA conditionally approve into Tennessee's SIP Tennessee Air Pollution Control Board operating permit No. 077509 for Eastman, state effective on August 11, 2021, to provide alternative NO X monitoring and reporting for Natural Gas-Fired Boilers 25-29 (PES B-253-1) at this facility in accordance with 40 CFR 51.121(i). TDEC requests that this approval be conditioned on Tennessee's commitment to modify the provisions at chapter 1200-03-27.12(11) to specify permissible alternative monitoring and reporting methodologies for large industrial non-EGUs subject to the NO X SIP Call, such as the alternative monitoring and reporting provisions in permit No. 077509. The submission also includes a demonstration under CAA section 110(l) intended to show that the revision would not interfere with any applicable requirement concerning attainment and reasonable further progress or any other applicable requirement of the CAA. As discussed later in this document, EPA has reviewed these changes, preliminarily finds them to be consistent with the CAA and regulations governing the NO X SIP Call, and is proposing to conditionally approve the revisions to incorporate the source-specific SIP revision into the State's implementation plan.

On September 17, 2019, Eastman submitted a petition to request approval of alternative monitoring, recordkeeping, and reporting requirements for five boilers subject to the NO X SIP Call (Boilers 25, 26, 27, 28, and 29) at Eastman's B-253 powerhouse. The petition states that NO X emission rates from Eastman's B-253 boilers, which were converted from coal to natural gas operation between 2013 and 2018, are approximately 20% of the pre-conversion NO X emission rates. As a result, Eastman operates with a substantial margin of compliance relative to the facility's NO X allocation of 3,047 tons. 8 The petition states that Eastman emitted 70% of its allocation during the 2018 ozone season. The petition also notes that if Boiler 26 had been converted to gas for the 2018 control period, Eastman would have emitted approximately 60% of its allocation. The petition indicates that these boilers burn only pipeline quality natural gas and that the units have had similar average NO X emission rates from 2016-2020. Specifically, the petition requested that Eastman be permitted to demonstrate compliance with Tennessee Rule 1200-03-27-.12 by monitoring NO X emissions from PES B-253-1, Boilers 25 through 29, using the monitoring methodology for NO X emission rate set forth in 40 CFR part 75, appendix E.

That petition resulted in TDEC's issuance of operating permit No. 077509 to address NO X SIP Call requirements and to adopt an alternative monitoring option (along with corresponding recordkeeping and reporting requirements) for this large non-EGU. Condition 1 of operating permit No. 077509 allows Eastman to use the alternative NO X monitoring provisions in Condition 2 in lieu of the requirements established by TAPCR 1200-03-27-.12(11)(a). Condition 2 provides that Eastman may demonstrate compliance with Tennessee Rule 1200-03-27-.12 by monitoring NO X emissions from PES B 253-1, Boilers 25 through 29, using the monitoring methodologies set forth in 40 CFR part 75, appendices D and E, except that the units shall not be required to meet the definition of a “peaking unit” under 40 CFR 72.2 as otherwise required under 40 CFR part 75, appendix E, section 1.1. Appendix E generally includes requirements for performance testing, periodic re-testing, procedures for determining the hourly NO X rate, quality assurance standards, recordkeeping requirements, and reporting requirements. 9 These revised permit conditions are consistent with the flexibility provided to states on March 8, 2019 (84 FR 8422) concerning the form of the NO X emissions monitoring requirements that the states must include in their SIPs for certain emissions sources, such as Eastman, to comply with the NO X SIP Call.

Section 110(l) of the CAA prohibits revision of a SIP that would interfere with attainment or maintenance of a NAAQS, reasonable further progress toward attainment of a NAAQS, or any other applicable requirement of the CAA. In its submittal, TDEC includes a demonstration in accordance with section 110(l) of the CAA that the proposed revision would not interfere with any applicable requirement concerning attainment and reasonable further progress, or any other applicable requirement of the CAA. Tennessee's demonstration concludes that the proposed changes are compliant with section 110(l) of the CAA because: (1) NO X emissions from Eastman's affected units, including B-253 Boilers 25 through 29, are substantially below the facility's NO X budget established pursuant to TAPCR 1200-03-27-.12, and the change would not result in an increase in NO X emissions; (2) the proposed monitoring alternative would not alter the NO X SIP Call budget that limits emissions from the affected unit; (3) the alternative monitoring requirements would be permanent, enforceable, and sufficient to determine whether the source is in compliance with the NO X SIP Call emissions requirements; and (4) the work practice requirements of 40 CFR 63, subpart DDDDD (periodic tune-ups) will provide additional assurance that the boilers are operating properly. EPA agrees with Tennessee's rationale summarized above and the conclusion that the proposed revision would not interfere with any applicable requirement concerning attainment and reasonable further progress, or any other applicable requirement of the CAA.

In order to address the requirements of the NO X SIP Call for sources that are not covered under a CSAPR trading program for ozone season NO X emissions, SIP revisions must provide for enforceable emissions limitations and require emissions monitoring consistent with the NO X SIP Call's general enforceability and monitoring requirements. 10 See 40 CFR 51.121(f)(2). EPA is proposing to find that TDEC's submittal meets these requirements and all other requirements of the CAA, including 40 CFR 51.121(i)(1) and (4), except that Tennessee additionally will need to modify TAPCR 1200-03-27.12(11) to specify permissible alternative monitoring and reporting methodologies within one year of the effective date of EPA's conditional approval. Thus, EPA is proposing to conditionally approve TDEC operating permit No. 077509, state effective on August 11, 2021, into Tennessee's SIP pursuant to CAA section 110(k)(4), subject to TDEC's specific commitment to modify the provisions of TAPCR 1200-03-27.12(11) to specify permissible alternative monitoring and reporting methodologies within one year of EPA's conditional approval, as described in TDEC's submittal.

If Tennessee meets its commitment to submit a SIP revision modifying the provisions of TAPCR 1200-03-27.12(11) to specify permissible alternative monitoring and reporting methodologies, as allowed under 40 CFR 51.121(i)(1) and (4), by 12 months from the date of final approval of this proposed action, TDEC operating permit No. 077509 will remain a part of the SIP. However, if the State fails to submit this revision on or before 12 months from the date of final approval of this action, the conditional approval will become a disapproval pursuant to CAA section 110(k)(4).

In this document, EPA is proposing to include in a final EPA rule regulatory text that includes incorporation by reference. In accordance with the requirements of 1 CFR 51.5, and as discussed in Sections I through III of this preamble, EPA is proposing to incorporate by reference Tennessee Air Pollution Control Board's operating permit No. 077509 for the Eastman Chemical Company, state effective on August 11, 2021. EPA has made, and will continue to make, these materials generally available through www.regulations.gov and at the EPA Region 4 Office (please contact the person identified in the For Further Information Contact section of this preamble for more information).

EPA is proposing to conditionally approve Tennessee Air Pollution Control Board operating permit No. 077509 for the Eastman Chemical Company, state effective August 11, 2021 for incorporation into the Tennessee SIP. These changes were submitted by Tennessee on August 11, 2021.

Under the CAA, the Administrator is required to approve a SIP submission that complies with the provisions of the CAA and applicable Federal regulations. See 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submissions, EPA's role is to approve state choices, provided that they meet the criteria of the CAA. This proposed action merely proposes to conditionally approve state law as meeting Federal requirements and does not impose additional requirements beyond those imposed by state law. For that reason, this proposed action:

• Is not a significant regulatory action subject to review by the Office of Management and Budget under Executive Orders 12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);

• Does not an impose information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq. );

• Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq. );

• Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);

• Does not have Federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999);

• Is not an economically significant regulatory action based on health or safety risks subject to Executive Order 13045 (62 FR 19885, April 23, 1997);

• Is not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, May 22, 2001);

• Is not subject to requirements of section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requirements would be inconsistent with the CAA; and

• Does not provide EPA with the discretionary authority to address, as appropriate, disproportionate human health or environmental effects, using practicable and legally permissible methods, under Executive Order 12898 (59 FR 7629, February 16, 1994).

The SIP is not approved to apply on any Indian reservation land or in any other area where EPA or an Indian tribe has demonstrated that a tribe has jurisdiction. In those areas of Indian country, the proposed rule does not have tribal implications as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), nor will it impose substantial direct costs on tribal governments or preempt tribal law.

Throughout this document, the terms “we,” “us,” and “our” refer to EPA.

The EPA is proposing action on a SIP submittal from Nevada that addresses the infrastructure requirements of CAA sections 110(a)(1) and 110(a)(2) for the 2015 ozone NAAQS. The requirement for states to submit a SIP revision of this type arises out of CAA section 110(a)(1). Pursuant to section 110(a)(1), states must make SIP submittals “within 3 years (or such shorter period as the Administrator may prescribe) after the promulgation of a national primary ambient air quality standard (or any revision thereof),” and these SIP submittals are to provide for the “implementation, maintenance, and enforcement” of such NAAQS. The statute directly imposes on states the duty to make these SIP submittals, and the requirement to make the submittals is not conditioned upon the EPA's taking any action other than promulgating a new or revised NAAQS. Section 110(a)(2) includes a list of specific elements that “[e]ach such plan” submittal must address.

The EPA has historically referred to these SIP submittals made for the purpose of satisfying the requirements of CAA sections 110(a)(1) and 110(a)(2) as “infrastructure SIP” submittals. Although the term “infrastructure SIP” does not appear in the CAA, the EPA uses the term to distinguish this particular type of SIP submittal from submittals that are intended to satisfy other SIP requirements under the CAA, such as “nonattainment SIP” or “attainment SIP” submittals to address the nonattainment planning requirements of part D of title I of the CAA, “regional haze SIP” submittals required to address the visibility protection requirements of CAA section 169A, and nonattainment new source review (NSR) permit program submittals to address the permit requirements of CAA, title I, part D.

Historically, the EPA has elected to use guidance documents to make recommendations to states for infrastructure SIPs, in some cases conveying needed interpretations on newly arising issues and in other cases conveying interpretations that have already been developed and applied to individual SIP submittals for particular elements. 1 The EPA most recently issued guidance for infrastructure SIPs on September 13, 2013 (“2013 Infrastructure SIP Guidance”). 2 The EPA developed this document to provide states with up-to-date guidance for infrastructure SIPs for any new or revised NAAQS. Within this guidance, the EPA describes the duty of states to make infrastructure SIP submittals to meet basic structural SIP requirements within three years of promulgation of a new or revised NAAQS. The EPA also made recommendations about many specific subsections of section 110(a)(2) that are relevant in the context of infrastructure SIP submittals. 3 The guidance also discusses the substantively important issues that are germane to certain subsections of section 110(a)(2). Significantly, the EPA interprets sections 110(a)(1) and 110(a)(2) such that infrastructure SIP submittals need to address certain issues and need not address others. Accordingly, the EPA reviews each infrastructure SIP submittal for compliance with the applicable statutory provisions of section 110(a)(2), as appropriate.

As an example, section 110(a)(2)(E)(ii) is a required element of section 110(a)(2) for infrastructure SIP submittals. Under this element, a state must meet the substantive requirements of section 128, which pertain to state boards that approve permits or enforcement orders and heads of executive agencies with similar powers. Thus, the EPA reviews infrastructure SIP submittals to ensure that the state's SIP appropriately addresses the requirements of section 110(a)(2)(E)(ii) and section 128. The 2013 Infrastructure SIP Guidance explains the EPA's interpretation that there may be a variety of ways by which states can appropriately address these substantive statutory requirements, depending on the structure of an individual state's permitting or enforcement program ( e.g., whether permits and enforcement orders are approved by a multi-member board or by a head of an executive agency). However they are addressed by the state, the substantive requirements of section 128 are necessarily included in the EPA's evaluation of infrastructure SIP submittals because section 110(a)(2)(E)(ii) explicitly requires that the state satisfy the provisions of section 128.

As another example, the EPA's review of infrastructure SIP submittals with respect to the PSD program requirements in sections 110(a)(2)(C), (D)(i)(II), and (J) focuses upon the structural PSD program requirements contained in part C, title I of the Act and the EPA's PSD regulations. Structural PSD program requirements include provisions necessary for the PSD program to address all regulated sources and regulated NSR pollutants, including greenhouse gases (GHGs). By contrast, structural PSD program requirements do not include provisions that are not required under EPA's regulations at 40 Code of Federal Regulations (CFR) 51.166 but are merely available as an option for the state, such as the option to provide grandfathering of complete permit applications with respect to the 2012 NAAQS for particulate matter of 2.5 micrometers or less (PM 2.5 ). Accordingly, the latter optional provisions are types of provisions the EPA considers irrelevant in the context of an infrastructure SIP action.

For other section 110(a)(2) elements, however, the EPA's review of a state's infrastructure SIP submittal focuses on assuring that the state's SIP meets basic structural requirements. For example, section 110(a)(2)(C) includes, inter alia, the requirement that states have a program to regulate minor new sources. Thus, the EPA evaluates whether the state has a SIP-approved minor NSR program and whether the program addresses the pollutants relevant to that NAAQS. In the context of acting on an infrastructure SIP submittal, however, the EPA does not think it is necessary to conduct a review of each and every provision of a state's existing minor source program ( i.e., already in the existing SIP) for compliance with the requirements of the CAA and the EPA's regulations that pertain to such programs.

With respect to certain other issues, the EPA does not believe that an action on a state's infrastructure SIP submittal is necessarily the appropriate type of action in which to address possible deficiencies in a state's existing SIP. These issues include existing provisions related to “director's variance” or “director's discretion” that may be contrary to the CAA because they purport to allow revisions to SIP-approved emissions limits while limiting public process or not requiring further approval by the EPA and existing provisions for PSD programs that may be inconsistent with current requirements of the EPA's “Final NSR Improvement Rule,” 67 FR 80186, December 31, 2002, as amended by 72 FR 32526, June 13, 2007 (“NSR Reform”). Thus, the EPA believes it may approve an infrastructure SIP submittal without scrutinizing the totality of the existing SIP for such potentially deficient provisions and may approve the submittal even if it is aware of such existing provisions. 4 It is important to note that the EPA's approval of a state's infrastructure SIP submittal should not be construed as explicit or implicit re-approval of any existing potentially deficient provisions that relate to the three specific issues just described.

The EPA's approach to the review of infrastructure SIP submittals is to identify the CAA requirements that are logically applicable to that submittal. The EPA believes that this approach to the review of a particular infrastructure SIP submittal is appropriate, because it would not be reasonable to read the general requirements of section 110(a)(1) and the list of elements in 110(a)(2) as requiring review of each and every provision of a state's existing SIP against all requirements in the CAA and the EPA regulations merely for purposes of assuring that the state in question has the basic structural elements for a functioning SIP for a new or revised NAAQS. Because SIPs have grown by accretion over the decades as statutory and regulatory requirements under the CAA have evolved, they may include some outmoded provisions and historical artifacts. These provisions, while not fully up to date, nevertheless may not pose a significant problem for the purposes of “implementation, maintenance, and enforcement” of a new or revised NAAQS when the EPA evaluates adequacy of the infrastructure SIP submittal. The EPA believes that a better approach is for states and the EPA to focus attention on those elements of section 110(a)(2) of the CAA most likely to warrant a specific SIP revision due to the promulgation of a new or revised NAAQS or other factors.

For example, the EPA's 2013 Infrastructure SIP Guidance gives simpler recommendations with respect to carbon monoxide than other NAAQS pollutants to meet the visibility requirements of section 110(a)(2)(D)(i)(II), because carbon monoxide does not affect visibility. As a result, an infrastructure SIP submittal for any future new or revised NAAQS for carbon monoxide need only state this fact in order to address the visibility prong of section 110(a)(2)(D)(i)(II).

Finally, the EPA believes that its approach with respect to infrastructure SIP requirements is based on a reasonable reading of sections 110(a)(1) and 110(a)(2) because the CAA provides other avenues and mechanisms to address specific substantive deficiencies in existing SIPs. These other statutory tools allow the EPA to take appropriately tailored action, depending upon the nature and severity of the alleged SIP deficiency. Section 110(k)(5) authorizes the EPA to issue a “SIP call” whenever the Agency determines that a state's SIP is substantially inadequate to attain or maintain the NAAQS, to mitigate interstate transport, or to otherwise comply with the CAA. 5 Section 110(k)(6) authorizes the EPA to correct errors in past actions, such as past approvals of SIP submittals. 6 Significantly, the EPA's determination that an action on a state's infrastructure SIP submittal is not the appropriate time and place to address all potential existing SIP deficiencies does not preclude the EPA's subsequent reliance on provisions in section 110(a)(2) as part of the basis for action to correct those deficiencies at a later time. For example, although it may not be appropriate to require a state to eliminate all existing inappropriate director's discretion provisions in the course of acting on an infrastructure SIP submittal, the EPA believes that section 110(a)(2)(A) may be among the statutory bases that the EPA relies upon in the course of addressing such deficiency in a subsequent action. 7

Section 110(a)(2) includes a list of specific elements that “[e]ach such plan” submission must include. The infrastructure SIP elements required by section 110(a)(2) are as follows:

• Section 110(a)(2)(A): Emission limits and other control measures.

• Section 110(a)(2)(B): Ambient air quality monitoring/data system.

• Section 110(a)(2)(C): Program for enforcement of control measures and regulation of new and modified stationary sources.

• Section 110(a)(2)(D)(i): Interstate pollution transport.

• Section 110(a)(2)(D)(ii): Interstate pollution abatement and international air pollution.

• Section 110(a)(2)(E): Adequate resources and authority, conflict of interest, and oversight of local government and regional agencies.

• Section 110(a)(2)(F): Stationary source monitoring and reporting.

• Section 110(a)(2)(G): Emergency episodes.

• Section 110(a)(2)(H): SIP revisions.

• Section 110(a)(2)(J): Consultation with government officials, public notification, PSD, and visibility protection.

• Section 110(a)(2)(K): Air quality modeling and submittal of modeling data.

• Section 110(a)(2)(L): Permitting fees.

• Section 110(a)(2)(M): Consultation and participation by affected local entities.

Two elements identified in section 110(a)(2) are not governed by the three-year submittal deadline of section 110(a)(1) and are therefore not addressed in this action. These two elements are: Section 110(a)(2)(C) to the extent it refers to permit programs required under part D (nonattainment NSR), and Section 110(a)(2)(I), pertaining to the nonattainment planning requirements of part D. As a result, this action does not address requirements for the nonattainment NSR portion of section 110(a)(2)(C) or the whole of section 110(a)(2)(I).

On October 26, 2015, the EPA promulgated a revised NAAQS for ozone, (“the 2015 ozone NAAQS”), triggering a requirement for states to submit infrastructure SIPs within three years of promulgation of the revised NAAQS. The 2015 ozone NAAQS revised the 2008 8-hour ozone NAAQS by lowering the primary and secondary 8-hour ozone standards from 75 parts per billion (ppb) to 70 ppb. 8

The Nevada Division of Environmental Protection (NDEP) submitted a SIP revision addressing the infrastructure SIP requirements for the 2015 ozone NAAQS on September 28, 2018 (“Nevada's Infrastructure SIP Submittal”). 9 It included separate sections for Clark County  10 and Washoe County. 11 We refer to each individual section as that agency's or County's portion of the submittal. In accordance with CAA section 110(k)(1)(B), the infrastructure SIP became complete by operation of law on March 28, 2019.

As noted in each respective portion of the submittal, NDEP, Clark County, and Washoe County all provided public notice and an opportunity for public comment prior to finalizing each portion of the infrastructure SIP submittal. Additionally, each agency either held or offered to hold a public hearing as part of the public notice and comment period. Notice, hearing, and adoption dates for each portion of the submittal are shown in Table 1. We find that these submittals meet the procedural requirements for public participation under CAA section 110(a)(2) and 40 CFR 51.102.

Throughout this document, “we,” “us,” and “our” refer to the EPA.

Effective July 20, 2012, the EPA designated and classified the Riverside County (Coachella Valley), California, nonattainment area (“Coachella Valley”) as “Severe-15” nonattainment for the 2008 ozone NAAQS. 1 Air quality in the Coachella Valley is jointly overseen by the South Coast Air Quality Management District (“District”) and the California Air Resources Board (CARB). The Coachella Valley is located within a portion of Riverside County, and its geographic borders also include Indian country under the jurisdiction of six federally recognized tribes. 2 Our classification of the Coachella Valley as a Severe-15 ozone nonattainment area established a requirement that the area attain the 2008 ozone NAAQS as expeditiously as practicable, but no later than 15 years from the date of designation as nonattainment, i.e., July 20, 2027. 3

On November 15, 2022, CARB submitted a request to the EPA seeking a voluntary reclassification of the Coachella Valley from Severe-15 to Extreme for the 2008 ozone NAAQS. 4 We are proposing to approve CARB's reclassification request under the “voluntary reclassification” provisions of section 181(b)(3) of the Act, which mandates that the EPA approve such a request. Upon final reclassification, the applicable attainment dates will be as expeditiously as practicable, but no later than 20 years from the area's date of designation as nonattainment, i.e., July 20, 2032.

Because the State of California does not have jurisdiction over Indian country geographically located within the borders of the state, CARB's request to reclassify the Coachella Valley does not apply to Indian country under the jurisdiction of the tribes identified in 40 CFR 81.305. In these areas of Indian country, the EPA implements federal CAA programs, including reclassifications, consistent with our discretionary authority under sections 301(a) and 301(d)(4) of the CAA. When the EPA designated the Coachella Valley as nonattainment for the 2008 ozone NAAQS, we included the jurisdictional lands of the six federally recognized tribes located within the boundaries of the nonattainment area: the Agua Caliente Band of Cahuilla Indians; the Augustine Band of Cahuilla Mission Indians; the Cabazon Band of Cahuilla Indians;  5 the Santa Rosa Band of Cahuilla Indians; the Torres Martinez Desert Cahuilla Indians; and the Twenty-Nine Palms Band of Mission Indians.

This action does not reclassify any areas of Indian country within the Coachella Valley. Under the EPA's Consultation Policy, the EPA consults on a government-to-government basis with federally recognized tribal governments when the EPA's actions and decisions may affect tribal interests. 6 The EPA is currently undergoing this consultation process and any proposed reclassification of tribal lands will be addressed in a future rulemaking action.

On February 19, 2015, the Coast Guard published a notice of proposed rulemaking (NPRM) titled “Commercial Diving Operations” in the Federal Register (80 FR 9152). 1 The intent of the proposed rulemaking was to amend the regulations for commercial diving conducted from deepwater ports or deepwater port safety zones, in connection with Outer Continental Shelf activities, or from vessels that are required to have a Coast Guard certificate of inspection. The proposed rulemaking sought to amend these regulations to improve the safety of people and property involved in commercial diving operations and to protect the environment in which they operate, as well as to include current industry best practices. The proposed regulations also aimed to allow the Coast Guard to approve independent third-party organizations to assist with ensuring regulatory compliance of commercial diving regulations.

The Coast Guard is withdrawing the proposed rule published on February 19, 2015. Upon further review of commercial diving technologies and standards, it is evident that significant changes have occurred in the industry and we no longer consider the original proposal an appropriate solution.

The Coast Guard will continue to assess the standards and technologies used and practiced in the commercial diving industry, support the continued development of commercial diving standards to improve commercial diving safety, oversee the work of recognized organizations, and request input from our Federal advisory committees as appropriate. The Coast Guard may decide to develop new rulemaking proposals in the future, but Unified Agenda item 1625-AA21 will be withdrawn once this notice is published.

This notice is issued under authority of 5 U.S.C. 552(a).

On August 4, 2022, the Secretary of Commerce received a petition from the Native Fish Society, Center for Biological Diversity, and Umpqua Watersheds (hereafter, the Petitioners) to list the OC and SONCC Chinook salmon ESUs as threatened or endangered under the ESA or, alternatively, list only spring-run Chinook salmon in both the OC and SONCC ESUs as threatened or endangered under the ESA. The Petitioners also request the designation of critical habitat concurrent with ESA listing. Copies of the petition are available as described above (see ADDRESSES ).

Section 4(b)(3)(A) of the ESA of 1973, as amended (16 U.S.C. 1531 et seq. ), requires, to the maximum extent practicable, that within 90 days of receipt of a petition to list a species as threatened or endangered, the Secretary of Commerce make a finding on whether that petition presents substantial scientific or commercial information indicating that the petitioned action may be warranted, and to promptly publish such finding in the Federal Register (16 U.S.C. 1533(b)(3)(A)). When it is found that substantial scientific or commercial information in a petition indicates the petitioned action may be warranted (a “positive 90-day finding”), we are required to promptly commence a review of the status of the species concerned during which we will conduct a comprehensive review of the best available scientific and commercial information. In such cases, we conclude the review with a finding as to whether the petitioned action is warranted within 12 months of receipt of the petition. Because the finding at the 12-month stage is based on a more thorough review of the available information, as compared to the narrow scope of review at the 90-day stage, a “may be warranted” finding does not prejudge the outcome of the status review.

Under the ESA, a listing determination may address a species, which is defined to also include subspecies and, for any vertebrate species, any distinct population segment (DPS) that interbreeds when mature (16 U.S.C. 1532(16)). In 1991, we issued the Policy on Applying the Definition of Species Under the Endangered Species Act to Pacific Salmon (ESU Policy; 56 FR 58612, November 20, 1991), which explains that Pacific salmon populations will be considered a DPS, and hence a “species” under the ESA, if it represents an “evolutionarily significant unit” of the biological species. The two criteria for delineating an ESU are: (1) It is substantially reproductively isolated from other conspecific populations, and (2) it represents an important component in the evolutionary legacy of the species. The ESU Policy was used to define the OC and SONCC Chinook salmon ESUs in 1999 (64 FR 50394, September 16, 1999), and we use it exclusively for defining distinct population segments of Pacific salmon. A joint NMFS-U.S. Fish and Wildlife Service (USFWS) (jointly, “the Services”) policy clarifies the Services' interpretation of the phrase “distinct population segment” for the purposes of listing, delisting, and reclassifying a species under the ESA (DPS Policy; 61 FR 4722, February 7, 1996). In announcing this policy, the Services indicated that the ESU Policy for Pacific salmon was consistent with the DPS Policy and that NMFS would continue to use the ESU Policy for Pacific salmon.

A species, subspecies, or DPS is “endangered” if it is in danger of extinction throughout all or a significant portion of its range, and “threatened” if it is likely to become endangered within the foreseeable future throughout all or a significant portion of its range (ESA sections 3(6) and 3(20), respectively, 16 U.S.C. 1532(6) and (20)). Pursuant to the ESA and our implementing regulations, we determine whether species are threatened or endangered based on any one or a combination of the following five section 4(a)(1) factors: the present or threatened destruction, modification, or curtailment of habitat or range; overutilization for commercial, recreational, scientific, or educational purposes; disease or predation; inadequacy of existing regulatory mechanisms to address identified threats; or any other natural or manmade factors affecting the species' existence (16 U.S.C. 1533(a)(1), 50 CFR 424.11(c)).

ESA-implementing regulations issued jointly by NMFS and USFWS (50 CFR 424.14(h)(1)(i)) define “substantial scientific or commercial information” in the context of reviewing a petition to list, delist, or reclassify a species as “credible scientific or commercial information in support of the petition's claims such that a reasonable person conducting an impartial scientific review would conclude that the action proposed in the petition may be warranted.” Conclusions drawn in the petition without the support of credible scientific or commercial information will not be considered “substantial information.” In reaching the initial (90-day) finding on the petition, we consider the information described in sections 50 CFR 424.14(c), (d), and (g) (if applicable).

Our determination as to whether the petition provides substantial scientific or commercial information indicating that the petitioned action may be warranted will depend in part on the degree to which the petition includes the following types of information: (1) Information on current population status and trends and estimates of current population sizes and distributions, both in captivity and the wild, if available; (2) identification of the factors under section 4(a)(1) of the ESA that may affect the species and where these factors are acting upon the species; (3) whether and to what extent any or all of the factors alone or in combination identified in section 4(a)(1) of the ESA may cause the species to be an endangered species or threatened species ( i.e., the species is currently in danger of extinction or is likely to become so within the foreseeable future), and, if so, how high in magnitude and how imminent the threats to the species and its habitat are; (4) information on adequacy of regulatory protections and effectiveness of conservation activities by States as well as other parties, that have been initiated or that are ongoing, that may protect the species or its habitat; and (5) a complete, balanced representation of the relevant facts, including information that may contradict claims in the petition. See 50 CFR 424.14(d).

If the petitioner provides supplemental information before the initial finding is made and states that it is part of the petition, the new information, along with the previously submitted information, is treated as a new petition that supersedes the original petition, and the statutory timeframes will begin when such supplemental information is received. See 50 CFR 424.14(g).

We may also consider information readily available at the time the determination is made (50 CFR 424.14(h)(1)(ii)). We are not required to consider any supporting materials cited by the petitioner if the petitioner does not provide electronic or hard copies, to the extent permitted by U.S. copyright law, or appropriate excerpts or quotations from those materials ( e.g., publications, maps, reports, letters from authorities). See 50 CFR 424.14(c)(6).

The “substantial scientific or commercial information” standard must be applied in light of any prior reviews or findings we have made on the listing status of the species that is the subject of the petition. Where we have already conducted a finding on, or review of, the listing status of that species (whether in response to a petition or on our own initiative), we will evaluate any petition received thereafter seeking to list, delist, or reclassify that species to determine whether a reasonable person conducting an impartial scientific review would conclude that the action proposed in the petition may be warranted despite the previous review or finding. Where the prior review resulted in a final agency action—such as a final listing determination, 90-day not-substantial finding, or 12-month not-warranted finding—a petitioned action will generally not be considered to present substantial scientific and commercial information indicating that the action may be warranted unless the petition provides new information or analysis not previously considered. See 50 CFR 424.14(h)(1)(iii).

At the 90-day finding stage, we do not conduct additional research, and we do not solicit information from parties outside the agency to help us in evaluating the petition. We will accept the petitioners' sources and characterizations of the information presented if they appear to be based on accepted scientific principles, unless we have specific information in our files that indicates the petition's information is incorrect, unreliable, obsolete, or otherwise irrelevant to the requested action. Information that is susceptible to more than one interpretation or that is contradicted by other available information will not be dismissed at the 90-day finding stage, so long as it is reliable and a reasonable person conducting an impartial scientific review would conclude it supports the petitioners' assertions. In other words, conclusive information indicating that the species may meet the ESA's requirements for listing is not required to make a positive 90-day finding. We will not conclude that a lack of specific information alone necessitates a negative 90-day finding if a reasonable person conducting an impartial scientific review would conclude that the unknown information itself suggests the species may be at risk of extinction presently or within the foreseeable future.

To make a 90-day finding on a petition to list a species, we evaluate whether the petition presents substantial scientific or commercial information indicating the subject species may be either threatened or endangered, as defined by the ESA. First, we evaluate whether the information presented in the petition, in light of the information readily available in our files, indicates that the petitioned entity constitutes a “species” eligible for listing under the ESA. Next, we evaluate whether the information indicates that the species faces an extinction risk such that listing, delisting, or reclassification may be warranted; this may be indicated in information expressly discussing the species' status and trends, or in information describing impacts and threats to the species. We evaluate any information on specific demographic factors pertinent to evaluating extinction risk for the species ( e.g., population abundance and trends, productivity, spatial structure, age structure, sex ratio, diversity, current and historical range, habitat integrity or fragmentation), and the potential contribution of identified demographic risks to extinction risk for the species. We then evaluate the potential links between these demographic risks and the causative impacts and threats identified in section 4(a)(1).

Information presented on impacts or threats should be specific to the species and should reasonably suggest that one or more of these factors may be operative threats that act or have acted on the species to the point that it may warrant protection under the ESA. Broad statements about generalized threats to the species, or identification of factors that could negatively impact a species, alone, do not constitute substantial information indicating that listing may be warranted. We look for information indicating that not only is the particular species exposed to a factor, but that the species may be responding in a negative fashion; then we assess the potential significance of that negative response.

Many petitions identify risk classifications made by nongovernmental organizations, such as the International Union for Conservation of Nature (IUCN), the American Fisheries Society, or NatureServe, as evidence of extinction risk for a species. Risk classifications by such organizations or made under other Federal or State statutes may be informative, but such classification alone may not provide the rationale for a positive 90-day finding under the ESA. For example, as explained by NatureServe, their assessments of a species' conservation status do “not constitute a recommendation by NatureServe for listing under the U.S. Endangered Species Act” because NatureServe assessments “have different criteria, evidence requirements, purposes and taxonomic coverage than government lists of endangered and threatened species, and therefore these two types of lists should not be expected to coincide” ( https://explorer.natureserve.org/AboutTheData/DataTypes/ConservationStatusCategories ). Additionally, species classifications under IUCN and the ESA are not equivalent; data standards, criteria used to evaluate species, and treatment of uncertainty are also not necessarily the same. Thus, when a petition cites such classifications, we will evaluate the source of information that the classification is based upon in light of the standards on extinction risk and impacts or threats discussed above.

On March 9, 1998, following completion of a comprehensive status review of Chinook salmon ( O. tshawytscha ) populations in Washington, Oregon, Idaho, and California, we published a proposed rule to list seven Chinook salmon ESUs as threatened or endangered under the ESA (63 FR 11482). In this proposed rule, we identified the OC Chinook salmon ESU as comprised of coastal populations of spring- and fall-run Chinook salmon from the Elk River north to the mouth of the Columbia River. We did not propose to list the OC ESU of Chinook salmon under the ESA, concluding that the ESU was neither in danger of extinction nor likely to become endangered in the foreseeable future.

On September 16, 1999, following an updated status review for four Chinook salmon ESUs, we published a final rule to list two Chinook salmon ESUs as threatened under the ESA (64 FR 50394). In that final rule, we identified the SONCC Chinook salmon ESU as composed of coastal populations of spring- and fall-run Chinook salmon from Euchre Creek, Oregon, through the Lower Klamath River, California (inclusive) (64 FR 50394). After assessing information concerning Chinook salmon abundance, distribution, population trends, and risks, and after considering efforts being made to protect Chinook salmon, we determined in that final rule that the SONCC ESU of Chinook salmon did not warrant listing under the ESA.

On September 24, 2019, the Secretary of Commerce received a petition from the Native Fish Society, Center for Biological Diversity, and Umpqua Watersheds to identify OC spring-run Chinook salmon as a separate ESU and list the ESU as threatened or endangered under the ESA. On May 4, 2020, the Secretary of Commerce received a petition from Richard K. Nawa to identify SONCC spring-run Chinook salmon as a separate ESU and list the ESU as threatened or endangered under the ESA.

We completed a comprehensive analysis of OC and SONCC spring-run Chinook salmon populations in response to the petitions and announced our 12-month findings on August 17, 2021 (86 FR 45970). Based on the best scientific and commercial data available we determined that listing the OC and SONCC spring-run Chinook salmon populations as threatened or endangered ESUs was not warranted. We determined that the OC and SONCC spring-run Chinook salmon populations do not meet the ESU Policy criteria to be classified as ESUs separate from the OC and SONCC fall-run Chinook salmon populations and, therefore, do not meet the statutory definition of a species under the ESA.

The petition contains information and assertions in support of listing the OC Chinook salmon ESU and SONCC Chinook salmon ESU, or, alternatively, listing only the spring-run components of the OC and SONCC Chinook salmon ESUs. Under the spring-run-only alternative, the Petitioners state that the entire contents of their previous petitions are expressly incorporated in the current petition by reference. As described above, in response to the previous petitions we completed a comprehensive analysis of OC and SONCC spring-run Chinook salmon populations and concluded that they do not meet the statutory definition of a species under the ESA. The Petitioners do not provide any new information to support identifying and listing spring-run only OC and SONCC Chinook salmon ESUs as threatened or endangered species under the ESA. Based on information provided by the Petitioners, we find that the petition does not present substantial scientific and commercial information indicating that identifying and listing a spring-run only OC and SONCC Chinook salmon ESUs may be warranted. Therefore, we will focus on the Petitioner's claims that the previously identified OC and SONCC Chinook salmon ESUs warrant listing as a threatened or endangered species under the ESA.

Although the Petitioners request that we list the entire OC Chinook salmon ESU, which consists of spring-run and fall-run components, the Petitioners focus their analysis of status and trends and threats on the spring-run component of the ESU. There is very little information in the petition about the status and trends and threats facing the fall-run component of the ESU.

The Petitioners assert that spring-run Chinook salmon populations in the OC Chinook salmon ESU have suffered significant declines in numbers from historical abundance. The Petitioners assert that former spring-run populations in the Siuslaw, Coos, and Salmon rivers are apparently extirpated and that small, very depressed populations of spring-run Chinook salmon remain in the Tillamook, Nestucca, Siletz, Alsea, and Coquille Rivers (Percy et al., 1974; Nicholas and Hankin 1989; Kostow et al., 1995; ODFW 2005; ODFW 2017; ODFW 2018 unpublished data; Rasmussen and Nott 2019). The Oregon Department of Fish and Wildlife (ODFW, 2005) concluded that the Siletz spring-run Chinook salmon population, although small, passed all assessment criteria and was not considered at risk. ODFW (2005) further found that spring-run Chinook salmon populations in the Coquille and Alsea Rivers were sufficiently spatially diverse, independent, and free of hybridization, but due to chronically low adult returns were still considered potentially at risk. Citing the above information sources and adult counts at Winchester Dam, the Petitioners also assert that the North Umpqua River supports the only remaining large spring-run Chinook salmon population in the OC Chinook salmon ESU, but conclude recent surveys by the U.S. Forest Service and viability analyses by other researchers (Ratner and Lande, 1996) indicate the South Umpqua River run has been severely depleted.

The Petitioners also call attention to the Oregon Department of Fish and Wildlife's Coastal Multi-Species Conservation and Management Plan (CMP) (ODFW, 2014) and fish counts at Winchester Dam (ODFW, 2019) in support of their assertions that spring-run Chinook salmon populations are at risk of extinction. The CMP is the State of Oregon's plan for long-term conservation of naturally-produced salmon, steelhead, and trout on the Oregon Coast. The CMP identifies populations within the OC Chinook salmon ESU, and recognizes that while there are spring-run life history variants present in many of the OC Chinook salmon populations, only the North and South Umpqua Rivers support runs that are sufficiently isolated to be considered independent spring-run Chinook salmon populations (ODFW, 2014). Spring-run Chinook salmon in the North Umpqua River were found to be viable, although with a decreasing trend in abundance (1972-2010). South Umpqua spring-run Chinook salmon had a low extinction risk (<5 percent) and an increasing trend in abundance (1972-2010), but the population was considered non-viable because the current abundance was low and carrying capacity estimated to be less than necessary to maintain evolutionary potential to persist in future conditions (ODFW, 2014). The CMP assessments for OC Chinook salmon populations outside of the Umpqua Basin, which use the predominant fall-run Chinook salmon to evaluate population viability, found all populations were viable except for Elk River.

The Oregon Department of Fish and Wildlife maintains a fish counting station at Winchester Dam on the North Umpqua River. Although the most recent (2011-2018) average Winchester Dam counts of spring-run Chinook salmon in the North Umpqua show an improvement over historic lows, these counts indicate a decreasing trend of natural-origin adult returns over the last 8 years (ODFW, 2019). Fieldwork conducted in 2019 by an inter-agency team confirmed that abundance of spring-run Chinook salmon in the South Umpqua remains low after recent declines (Kruzic, 2019).

Based on information provided by the Petitioners, as well as information readily available in our files, we find that a reasonable person would conclude current demographic risks indicate that OC Chinook salmon may be at risk of extinction and thus their status warrants further investigation.

While the petition presents information on each of the ESA section 4(a)(1) factors, we find that the information presented, including information within our files, regarding the destruction, modification, or curtailment of the species habitat or range, the inadequacy of existing regulatory mechanisms, and other natural or manmade factors affecting the species continued existence is substantial enough to make a determination that a reasonable person would conclude that the species may warrant listing as endangered or threatened based on these factors alone. As such, we focus our below discussion on the evidence and present our evaluation of the information regarding these factors and their impact on the extinction risk of the species.

The Petitioners assert that OC Chinook salmon face numerous threats to suitable habitat, including impacts from historical and ongoing logging practices, agricultural practices, channelization, and urbanization. NMFS' OC coho salmon 5-year review (NMFS, 2022) evaluated the status of habitat threats over an area almost completely co-extensive with the range of OC Chinook salmon and concluded that degraded habitat conditions in this area continue to be of concern, particularly with regard to land use and development activities that affect the quality and accessibility of habitats and habitat-forming processes.

The Petitioners assert that habitat degradation due to logging and roads reduces stream shade, increases fine sediment levels, reduces levels of in-stream large wood, and alters watershed hydrology, which is supported by similar conclusions in NMFS' 2011 Final Rule listing OC coho salmon under the ESA (76 FR 35755, June 20, 2011), describing habitat that is co-extensive with the range of OC Chinook salmon. The Petitioners specifically assert that extensive logging can be harmful to Chinook salmon populations by causing depletion of summer and early fall streamflows needed for adult migration, holding, and spawning. Perry and Jones (2017) found that after an initial delay, base streamflows were substantially decreased for decades in logged areas as compared to pre-logging conditions. The Petitioners also assert that timber harvest and road construction harm OC Chinook salmon by altering stream flow, increasing sediment loading, contaminant concentrations, and temperatures, and decreasing dissolved oxygen. References to NMFS' 2011 OC coho salmon listing (76 FR 35755, June 20, 2011) and U.S. Bureau of Land Management (USBLM) analysis of timber harvest in the Siletz River watershed (USBLM, 1996) support their assertion.

The Petitioners further assert that dams, water diversions, and other barriers impact OC Chinook salmon by blocking suitable riverine habitat, impeding migration, and reducing water quality and quantity. NMFS' 2011 OC coho listing concluded that fish passage has been blocked in many streams by improperly designed culverts and is limited in estuaries by tide gates in the range of the OC coho salmon ESU. The Petitioners assert that large dams significantly reduce the amount of spawning and rearing habitat accessible to migrating Chinook salmon. However, the Oregon Native Fish Status Report (ODFW, 2005) concluded that essentially all potential OC Chinook salmon habitat remains accessible (although recognizing this assessment did not capture fine-scale blockages, such those caused by culverts). The Petitioners also assert that dams (large and small), reservoirs, diversions, and other barriers can significantly delay upstream and downstream migration. The most recent NMFS 5-year review of OC coho salmon (NMFS, 2022) recognizes that impeded fish passage and habitat access is a concern in many watersheds within their range, although this is not considered a primary limiting factor.

The Petitioners assert that dams and diversions also have the potential to decrease downstream flows, and that decreased summer and fall baseflows can result in increased water temperatures that are harmful to OC Chinook salmon. As referenced in the petition, Bottom et al. (1985) cited low streamflows and high summer temperatures exacerbated by water withdrawals as problems for many streams (notably Tillamook Bay tributaries and Alsea, Siletz, Siuslaw, and Umpqua Rivers). The 2022 NMFS 5-year review of OC coho salmon recognizes water quality and quantity as primary or secondary limiting factors for many coastal basins, and the Oregon CMP (ODFW, 2014) lists low flows and high temperatures as primary limiting factors for OC Chinook salmon.

The Petitioners also highlight other ongoing anthropogenic disturbances that may cause habitat degradation, including gravel mining, pollutants, and stream channelization, which is consistent with findings in NMFS' 2011 Final Rule to list OC coho salmon and limiting factors (particularly reduced habitat complexity) identified in the 2022 NMFS OC coho salmon 5-year review.

Based on information provided by the Petitioners, as well as information readily available in our files, we find that habitat destruction and curtailment of their range may be posing a threat to the continued existence of OC Chinook salmon.

The Petitioners assert that existing Federal and State regulatory mechanisms are not sufficient to protect and recover OC Chinook salmon and their habitat. Although the Petitioners found harvest to be a concern above, the focus of their discussion in this section is on regulatory mechanisms for habitat protection.

The Petitioners state that co-occurrence of OC Chinook salmon with other ESA-listed species does afford them some habitat benefits where their ranges overlap. The range of Chinook salmon overlaps substantially with listed OC coho salmon and therefore falls almost entirely within OC coho salmon designated critical habitat. However, the Petitioners assert that there is little evidence that improved habitat protections under the ESA since OC coho salmon were listed have resulted in actions sufficient to lead to recovery of either species.

The Petitioners assert that the USBLM's resource management plans do not provide adequate protection for OC Chinook salmon. The Petitioners assert that allowable logging practices and aquatic conservation strategies under the resource management plans do not effectively protect OC Chinook salmon habitat. The Petitioners cite NMFS' comments in its review of the draft Environmental Impact Statement for the revision of the resource management plans (NMFS, 2015b) and later comments by conservation groups (NFS, 2015; American Rivers et al., 2016) to support their claim that the resource management plans are not sufficient to adequately maintain and restore riparian and aquatic habitat necessary for conservation of anadromous fish.

The Petitioners also assert that the U.S. Forest Service's forest plans do not provide adequate protection for OC Chinook salmon. The Petitioners contend that the National Forest Management Act does not effectively limit long-term impacts to salmon habitat in Oregon Coast watersheds because it does not prohibit the U.S. Forest Service from carrying out management actions and projects that harm the species or habitat. Petitioners also assert that National Forest Plans have limited ability to protect OC Chinook salmon habitat because National Forest lands make up a small portion of Oregon Coast watersheds relative to private lands.

The Petitioners further assert that the licensing process for non-Federal hydropower projects does not necessarily provide adequate protections for OC Chinook salmon. The Federal Power Act mandates that when issuing licenses the Federal Energy Regulatory Commission include conditions to protect, mitigate, and enhance fish and wildlife affected by hydropower projects. The Petitioners assert that although the Commission must seek recommendations from the USFWS and NMFS, the Commission can reject such measures if they determine there is not substantial evidence of need, and the timeline of most licenses (30-50 years) limits the opportunity for future improvements. Petitioners also assert that water quality protections under the Coastal Zone Management Act and Clean Water Act are not adequately protective of OC Chinook salmon habitat. The Petitioners cite to NOAA's and the Environmental Protection Agency's findings that Oregon's coastal nonpoint pollution control program is inadequate (NOAA and EPA, 2013), and NMFS' conclusion that Clean Water Act programs are not sufficient to protect Oregon Coast coho salmon habitat (NMFS, 2015).

The Petitioners additionally assert that State forest management is also not adequately protective of salmon habitat. The Petitioners cite NMFS' comments, from the 2011 Final Rule listing OC coho salmon under the ESA (76 FR 35755, June 20, 2011), that the Oregon Forest Practices Act may not adequately protect OC coho salmon habitat in support of their assertion that it is therefore unlikely to protect OC Chinook salmon habitat. The Petitioners further point to an evaluation by Talberth and Fernandez (2015), which found the Oregon Forest Practices Act does not provide stream buffers in all areas adequate to protect water quality and habitat for fish and wildlife and allows clearcutting in areas prone to landslides and with cold-water fish habitat, in support of their conclusion that the Act does not adequately limit harmful clearcutting practices. The Petitioners also assert that the 2010 Northwest Oregon Forest Management Plan and the Elliot Forest Management Plan do not contain sufficient measures to manage or protect OC Chinook salmon and, in support of this claim, reference NMFS' 2011 OC coho listing Final Rule which stated NMFS was unable to conclude these plans provide for OC coho salmon habitat capable of supporting viable populations during both good and poor marine conditions.

The Petitioners point out that there have been various State watershed and salmon management plans with goals for protecting and recovering salmon, including the 1991 Coastal Chinook Salmon Plan, 1997 Oregon Coastal Salmon Restoration Initiative, Siletz and Alsea River Basin Fish Management Plans, 2006 Oregon Conservation Strategy, and 2014 Coastal Multispecies Conservation and Management Plan. However, Petitioners assert that despite all of these plans, OC Chinook salmon populations have continued to decline or remain at depressed levels, and State land managers continue to allow logging and other activities and programs that may harm salmon and degrade their habitat, indicating these plans are inadequate to protect OC Chinook salmon.

Based on information provided by the Petitioners, as well as information readily available in our files, we conclude there is sufficient indication that the inadequacy of existing regulatory mechanisms may be posing a threat to the continued existence of OC Chinook salmon.

The Petitioners assert that fish hatcheries have negative impacts on OC Chinook salmon by causing competition in the wild between hatchery and wild fish, supporting mixed-stock fisheries that have disproportionately harmed wild Chinook salmon, and promoting hybridization between spring- and fall-run Chinook salmon. The Petitioners assert that hatchery programs within the OC Chinook salmon ESU are intended for fisheries augmentation, and there are no conservation or reintroduction hatchery programs at this time.

The Oregon CMP (ODFW, 2014) has recognized hatcheries as a primary limiting factor for OC Chinook salmon in the Elk River, a secondary risk factor for stocks in the Salmon River, and a potential limiting factor for other OC Chinook salmon populations in the ESU. The risk associated with hatcheries as a limiting factor for these populations is primarily due to the potential genetic impacts of hatchery fish interbreeding with natural-origin fish on spawning grounds, although not specifically interbreeding between fall- and spring-run Chinook salmon. The potential for competition between naturally-produced and hatchery-origin fish is also recognized. However, the specific effects of coastal hatchery programs have not been systematically assessed (ODFW, 2014).

The Petitioners also assert that ongoing threats of poor ocean conditions and climate change are likely to threaten the continued existence of OC Chinook salmon. As described in NMFS' 5-year reviews (Stout et al., 2012; NMFS, 2016; NMFS, 2022) and ESA listing of OC coho salmon (76 FR 35755, June 20, 2011), variability in ocean conditions in the Pacific Northwest is a concern for the persistence of Oregon Coast salmonids because it is uncertain how populations will fare in periods of poor ocean survival when freshwater and estuarine habitats are degraded. The Petitioners also cite these NMFS sources to support their assertions that predicted effects of climate change are expected to negatively affect Oregon Coast salmonids through many different pathways, and cite the Oregon CMP (ODFW, 2014) in support of their statement that regional changes in climate and weather patterns will negatively impact Oregon coastal aquatic ecosystems and salmonids.

The Petitioners also assert that predicted climate change impacts on streamflows will be exacerbated by continued forest land use practices. The Petitioners cite studies demonstrating recent declines in Pacific Northwest streamflows and predicting increasing temperatures in downstream reaches (Luce and Holden, 2009; Isaak et al., 2018) in support of their assertion that decreases in streamflow caused by logging will exacerbate streamflow decreases and temperature increases likely to occur due to climate change.

Based on information provided by the Petitioners, as well as information readily available in our files, we conclude that hatcheries and climate change may be posing threats to the continued existence of OC Chinook salmon.

Although the Petitioners request that we list the entire SONCC Chinook salmon ESU, which consists of spring-run and fall-run components, the Petitioners focus their analysis of status and trends and threats on the spring-run component of the ESU. There is very little information in the petition about the status and trends and threats facing the fall-run component of the ESU.

The Petitioners assert that spring-run Chinook salmon populations in the SONCC Chinook salmon ESU have suffered significant declines in numbers from historical abundance. The Petitioners cite findings by Nicholas and Hankin (1989) that all spring-run Chinook salmon populations on the Oregon coast are smaller than fall-run populations and are depressed from historical population sizes. The Petitioners present data from the Oregon Department of Fish and Wildlife (ODFW) that indicate a 25-year decline in abundance of spring-run Chinook salmon on the Rogue River (1981-2006) (ODFW, 2019). During a 10-year period (1970-1979) that spans the construction of the William Jess Dam (1977) on the Rogue River, an average of 28,052 adult spring-run Chinook salmon were counted annually. ODFW (2019) estimated that there were 10,240 adult spring-run Chinook salmon in 2017 and that the annual average for the years 2008-2017 was 9,663.

The Petitioners note that following ODFW's adoption of the Rogue Spring Chinook Conservation Plan in 2007, the average annual abundance of natural-origin adult spring-run Chinook salmon increased from 7,596 to 9,663 in 2017. The Petitioners assert that this increase of spring-run Chinook salmon in the Rogue River was likely a result of the removal of the Gold Hill, Savage Rapids, and Gold Ray dams, which allowed heterozygous and homozygous fall-run Chinook salmon to ascend upriver rapidly and spawn with homozygous spring-run Chinook. In the Final Rogue Spring Chinook Salmon Conservation Plan Comprehensive Assessment and Update, ODFW found that while the status of spring-run Chinook salmon improved over the past decade the 10-year average is below the desired threshold of 15,000 naturally produced adult spring-run Chinook salmon returning to the Rogue River annually (ODFW, 2019). The Petitioners also call attention to the Cole M. Rivers Hatchery and Genetic Management Plan that reports the smolt to adult return rate of Cole M. Rivers Hatchery spring-run Chinook salmon in the Rogue River has been below 1 percent since 2002 (ODFW, 2016). The Petitioners assert that the smolt to adult return rate for natural fish is also likely low.

The Petitioners further assert that the abundance of spring-run Chinook salmon in the Rogue River may actually be lower than reported. Hess et al. (2016), Prince et al. (2017) and Thompson et al. (2019) have studied the relationship between genetic material from a portion of the genome that includes the Greb1L gene (otherwise referred to as the Greb1L region of the genome) and run-timing in Chinook salmon and steelhead. The authors characterized the Greb1L region as two alleles (different forms) and three genotypes (different combinations of the alleles): Individuals with two early run-timing alleles (early-run homozygotes), individuals with two late run-timing alleles (late-run homozygotes), and individuals with one allele for the early and one for the late run-timing (heterozygotes). Thompson et al. (2019) asserted that there is a considerable amount of interbreeding between spring-run and fall-run Chinook salmon in the Rogue River as a result of dam construction. Thompson et al. (2019) analyzed samples from 2004 and reported that many of the spring-run Chinook salmon counted at Gold Ray dam were in fact heterozygotes.

The Petitioners also call attention to a declining trend in abundance of adult spring-run Chinook salmon in the Smith River. The Petitioners cite data from snorkel surveys of spring-run Chinook salmon in the South Fork, Middle Fork, and North Fork of the Smith River from 1982 to 2018 (Hanson, 2018). Hanson (2018) found that the number of adult spring-run Chinook salmon counted per mile (density) has been declining since survey counts peaked in 1996 at a density of 2.5 salmon per mile. Hanson (2018) reported that adult spring-run Chinook salmon densities have remained at less than 0.3 salmon per mile since 2007 (Hanson, 2018). The Petitioners assert that this decline in spring-run Chinook salmon indicates that the population within the Smith River is threatened with extinction.

Based on information provided by the Petitioners, as well as information readily available in our files, we conclude that SONCC Chinook salmon populations may be at risk of extinction and thus their status warrants further investigation.

While the petition presents information on each of the ESA section 4(a)(1) factors, we find that the information presented, including information within our files, regarding the destruction, modification, or curtailment of the species habitat or range, the inadequacy of existing regulatory mechanisms, and other natural or manmade factors affecting the species continued existence is substantial enough to make a determination that a reasonable person would conclude that the species may warrant listing as endangered or threatened based on these factors alone. As such, we focus our below discussion on the evidence and present our evaluation of the information regarding these factors and their impact on the extinction risk of the species.

The Petitioners assert that SONCC Chinook salmon face numerous threats to suitable habitat, including impacts from dams, logging practices, road building, and mining operations. The Army Corps of Engineers completed construction of William Jess Dam/Lost Creek Reservoir on the upper Rogue River in 1977. The Petitioners cite the Rogue Spring Chinook Salmon Conservation Plan Comprehensive Assessment and Update (ODFW, 2019) in support of their assertion that artificially enhanced summer stream flows from Lost Creek Reservoir are adversely affecting Chinook salmon. ODFW (2019) found that enhanced summer stream flows allow fall-run Chinook salmon to spawn upstream in habitat that historically was utilized primarily by Chinook salmon.

The Petitioners assert that artificially augmented high flows in August and September in the Rogue River may reduce egg to fry survival of spring-run Chinook salmon. If spring-run Chinook salmon spawn during high river flows in September, redds may be dewatered and embryos desiccated when releases from the Lost Creek Reservoir decrease during the reservoir fill season, which begins in January (ODFW, 2019). ODFW (2019) states that egg to fry survival has likely decreased as a result of redds being dewatered.

The Petitioners also assert that other anthropogenic disturbances have degraded Chinook salmon spawning habitat in the Rogue and Smith Rivers. Specifically, the Petitioners assert that increased fine sediments due to logging, road building, and mining have adversely affected spawning habitat which is supported by similar conclusions in NMFS' 1997 final rule listing the SONCC coho salmon ESU under the ESA (62 FR 24588, May 6, 1997), describing habitat that is co-extensive with the range of SONCC Chinook salmon.

NMFS' most recent SONCC coho salmon 5-year review (NMFS, 2016) evaluated the status of habitat threats over an area that includes the range of SONCC Chinook salmon and concluded that degraded habitat conditions in this area continue to be of concern, particularly with regard to insufficient instream flow, unsuitable water temperatures, and insufficient rearing habitat due to a lack of floodplain and channel structure. While restoration and regulatory actions have been undertaken to improve freshwater and estuary habitat conditions in the SONCC coho salmon ESU, habitat concerns remain throughout the range of the ESU particularly in regards to water quality, water quantity, and rearing habitat.

Based on information provided by the Petitioners, as well as information readily available in our files, we conclude that habitat destruction and curtailment of their range may be posing a threat to the continued existence of SONCC Chinook salmon.

The Petitioners assert that existing Federal and State regulatory mechanisms are not sufficient to protect and recover SONCC Chinook salmon and their habitat. The Petitioners state that the Oregon Native Fish Conservation Policy, The Rogue Spring Chinook Salmon Conservation Plan, and the Coles M. Rivers Hatchery and Genetic Management Plan do not provide safeguards to stabilize or reverse increases in Chinook salmon heterozygous for run timing. The Petitioners assert that insufficient measures have been taken to prevent the interbreeding between naturally produced Chinook salmon and hatchery produced Chinook salmon from the Cole M. Rivers Hatchery. The Petitioners further assert that the Rogue Fall Chinook Conservation Plan (ODFW, 2007) does not adequately address the risks of interbreeding with spring-run fish as a result of artificially augmented summer flows (ODFW, 2013).

The Petitioners note that Chinook salmon on the Rogue River are not listed as threatened or endangered under the Oregon State Endangered Species Act. The Petitioners assert that while the Rogue Spring Chinook Species Management Unit/SONCC ESU is on the Oregon Sensitive Species List, the designation does not provide regulatory protection for SONCC Chinook salmon.

The Petitioners assert that the Oregon Forest Practices Act and California forest practice rules do not provide adequate habitat protections for SONCC Chinook salmon. In support of their assertions the Petitioners refer to NMFS' 5-year review for SONCC coho salmon (NMFS, 2016). NMFS' (2016) SONCC coho salmon 5-year review evaluated the inadequacy of existing regulatory mechanisms over an area in large part co-extensive with the range of SONCC Chinook salmon and concluded that the Oregon Forest Practices Act does not provide adequate protection for SONCC coho salmon. NMFS (2016) noted that particular areas of concern include: (1) whether the widths of riparian management areas (RMAs) are sufficient to fully protect riparian functions and stream habitats; (2) whether operations allowed within RMAs will degrade stream habitats; (3) operations on high-risk landslide sites; and (4) watershed-scale effects. NMFS (2016) similarly expressed concerns with the adequacy of California's forest practice rules to provide protection for SONCC coho salmon. Specifically, NMFS recommended the addition of the following standards to California's forest practice rules: (1) provide Class II-S (standard) streams with the same protections afforded Class II-L (large) streams, (2) include provisions to ensure hydrologic disconnection between logging roads and streams, and (3) include provisions to avoid hauling logs on hydrologically connected streams during winter periods. Furthermore, NMFS concluded that the effects of past and present timber harvest activities in California continue to be an ongoing threat to the SONCC coho salmon ESU.

Based on information provided by the Petitioners, as well as information readily available in our files, we find that the inadequacy of existing regulatory mechanisms may be posing a threat to the continued existence of SONCC Chinook salmon.

The Petitioners assert that the Cole M. Rivers Hatchery threatens the future viability of Chinook salmon in the Rogue River. The Petitioners assert that operation of the Cole M. Rivers Hatchery poses a risk to natural origin Chinook salmon due to multiple factors including competition, predation, disease, and interbreeding. The Petitioners assert that the release of an average of 1.6 million Chinook salmon annually from the Cole M. Rivers Hatchery results in increased competition between naturally produced Chinook salmon and the more abundant artificially produced salmonids. As previously mentioned the Petitioners assert that hatchery produced coho salmon and steelhead prey upon natural origin Chinook salmon fry. The Petitioners further note that the hatchery is a known source of disease in Chinook salmon. Amandi et al. (1982) found that Chinook salmon in the Cole M. Rivers Hatchery were found to be infected with F. columnaris and that pathogen concentrations in the outflow from the hatchery were greater than concentrations from the other water bodies sampled. ODFW (2019) reported that it is unknown if the infected salmon were infected with F. columnaris before entering the hatchery or if the salmon contracted F. columnaris after entering the hatchery.

The Petitioners also assert that ongoing threats of poor ocean conditions and climate change are likely to threaten the continued existence of SONCC Chinook salmon. As described in NMFS' Oregon Coast coho salmon 5-year review (Stout et al., 2012; 76 FR 35755, June 20, 2011), variability in ocean conditions in the Pacific Northwest is a concern for the persistence of coastal Oregon Chinook salmon. The Petitioners also cite Stout et al. (2012) in support of assertions that predicted effects of climate change are expected to negatively affect coastal Oregon salmonids through many different factors. The Petitioners cite the Oregon Coastal Management Plan (ODFW, 2014) in support of their assertions that regional changes in climate and weather patterns will negatively impact SONCC coastal aquatic ecosystems and salmonids. The Petitioners cite Reiman and Isaaks (2010) to support their assertions that variable weather and warming events will become more frequent in the Pacific Northwest and continue to threaten SONCC Chinook salmon.

Based on information provided by the Petitioners, as well as information readily available in our files, we find that hatcheries and climate change may be posing threats to the continued existence of SONCC Chinook salmon.

After reviewing the information contained in the petition, as well as information readily available in our files, we conclude that the petition presents substantial scientific information indicating that the petitioned action to list the OC and SONCC Chinook salmon ESUs as threatened or endangered under the ESA may be warranted, and that the petition does not present substantial scientific and commercial information indicating that the petitioned action to list only the spring-run components of the OC and SONCC Chinook salmon ESUs may be warranted. Therefore, in accordance with section 4(b)(3)(A) of the ESA and NMFS' implementing regulations (50 CFR 424.14(h)(2)), we will commence a status review to determine whether the OC Chinook salmon ESU or the SONCC Chinook salmon ESU is in danger of extinction throughout all or a significant portion of their range, or likely to become so within the foreseeable future. After the conclusion of the status review, we will make a finding as to whether listing the OC or SONCC Chinook salmon ESU as endangered or threatened is warranted as required by section 4(b)(3)(B) of the ESA.

To ensure that our status reviews are informed by the best available scientific and commercial data, we are opening a 60-day public comment period to solicit information on the OC and SONCC Chinook salmon ESUs. We request information from the public, concerned governmental agencies, Native American tribes, the scientific community, agricultural and forestry groups, conservation groups, fishing groups, industry, or any other interested parties concerning the current and/or historical status of OC and SONCC Chinook salmon ESUs. Specifically, we request information regarding: (1) species abundance; (2) species productivity; (3) species distribution or population spatial structure; (4) patterns of phenotypic, genotypic, and life history diversity; (5) habitat conditions and associated limiting factors and threats; (6) ongoing or planned efforts to protect and restore the species and their habitats; (7) information on the adequacy of existing regulatory mechanisms, whether protections are being implemented, and whether they are proving effective in conserving the species; (8) data concerning the status and trends of identified limiting factors or threats; (9) information on targeted harvest (commercial and recreational) and bycatch of the species; (10) other new information, data, or corrections including, but not limited to, taxonomic or nomenclatural changes; and (11) information concerning the impacts of environmental variability and climate change on survival, recruitment, distribution, and/or extinction risk.

We request that all information be accompanied by: (1) supporting documentation such as maps, bibliographic references, or reprints of pertinent publications; and (2) the submitter's name, and any association, institution, or business that the person represents.

A complete list of all references cited herein is available upon request (See FOR FURTHER INFORMATION CONTACT ).