Comments Invited

The FAA invites interested people to take part in this rulemaking by sending written comments, data, or views. The most helpful comments reference a specific portion of the proposed special conditions, explain the reason for any recommended change, and include supporting data.

On September 26, 2022, NAT applied for a Supplemental Type Certificate to install suites in the passenger cabin of Boeing Model 787-9 series airplanes. While the comment period provided by the FAA for proposed special conditions has typically been thirty days, the FAA is providing twenty days in this instance, due to the pendency of the anticipated delivery date for the affected airplane models.

The FAA will consider all comments received by the closing date for comments, and will consider comments filed late if it is possible to do so without incurring delay. The FAA may change these special conditions based on the comments received.

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 www.regulations.gov, including any personal information you provide. The FAA will also post a report summarizing each substantive verbal contact received about these special conditions.

Confidential Business Information (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 these special conditions contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to these special conditions, 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 the indicated comments will not be placed in the public docket of these proposed special conditions. Send submissions containing CBI to the individual listed in the For Further Information Contact section above. Comments the FAA receives, which are not specifically designated as CBI, will be placed in the public docket for these proposed special conditions.

As stated above, NAT applied for a supplemental type certificate for the installation of suites in the passenger cabin in Boeing Model 787-9 series airplanes. The Boeing Model 787-9 airplane, currently approved under Type Certificate No. T00021SE, is a twin-engine transport category airplane, with a maximum seating capacity for 420 passengers, and a maximum take-off weight of 553,000 pounds.

Under the provisions of 14 CFR 21.101, NAT must show that the Boeing Model 787-9 airplane, as changed, continues to meet the applicable provisions of the regulations listed in Type Certificate No. T00021SE or the applicable regulations in effect on the date of application for the change, except for earlier amendments as agreed upon by the FAA.

If the Administrator finds that the applicable airworthiness regulations ( i.e., 14 CFR part 25) do not contain adequate or appropriate safety standards for the Boeing Model 787-9 airplane because of a novel or unusual design feature, special conditions are prescribed under the provisions of § 21.16.

Special conditions are initially applicable to the model for which they are issued. Should the applicant apply for a supplemental type certificate to modify any other model included on the same type certificate to incorporate the same novel or unusual design feature, these special conditions would also apply to the other model under § 21.101.

In addition to the applicable airworthiness regulations and special conditions, the Boeing Model 787-9 airplane must comply with the exhaust-emission requirements of 14 CFR part 34, and the noise-certification requirements of 14 CFR part 36.

The FAA issues special conditions, as defined in 14 CFR 11.19, in accordance with §  11.38, and they become part of the type-certification basis under §  21.101.

The Boeing Model 787-9 airplane will incorporate the following novel or unusual design feature:

Single-passenger suites with high walls that diminish occupant awareness of their surroundings in emergency situations. These suites are considered a novel design for transport category airplanes and were not considered when applicable airworthiness standards were created.

For the Model 787-9 airplane, NAT has proposed a customer option for the installation of six high wall suites (HWS) arranged in two rows of three suites each in a 1-1-1 configuration. The characteristics of this HWS design are unique such that the suite walls are higher than conventional mini-suites with partial height surroundings. While the walls for these suites do not extend fully up from the floor to the ceiling, such as those found in traditional “high wall” suites, their wall height of 60 inches is greater than the eye level of a 5th percentile female, impeding visual awareness and egress. These suites are also not remote from the main cabin (such as overhead crew rests). Additionally, the design of these suites is novel in the inclusion of berths that are accessible to the occupant of the suite during flight, unlike previous high wall suite designs.

Part 25 in its current form does not have regulations that address suite installations in the cabin with walls of height that reduce occupant visibility and situational awareness.

Due to the novel design features of these HWS, suitable passenger alerting, supplemental oxygen, and firefighting equipment and procedures are needed for this configuration to ensure occupant awareness in emergency situations. Furthermore, the proposed suite design necessitates the development of additional special conditions, including, but not limited to crew procedures for managing hazards and suite occupants, as well as maintaining cabin-egress route dimensions after deformation of the walls and seats.

The proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

As discussed above, these proposed special conditions are applicable to Boeing Model 787-9 series airplanes. Should the applicant apply for a supplemental type certificate to modify any other model included on the same type certificate to incorporate the same novel or unusual design feature, these special conditions would apply to the other model as well.

This action affects only a certain novel or unusual design feature on one model of airplane. It is not a rule of general applicability and affects only the applicant who applied to the FAA for approval of these features on the airplane.

The authority citation for these special conditions is as follows:

Accordingly, the Federal Aviation Administration (FAA) proposes the following special conditions as part of the type certification basis for Boeing Model 787-9 series airplanes, as modified by NAT.

The suites must have the following features:

1. A supplemental oxygen system with the following:

a. Oxygen masks for each seat and berth installed in the suite that meets the same 14 CFR part 25 regulations as the supplemental oxygen system for the main passenger-cabin occupants.

b. An aural and visual alert system to warn occupants and to indicate the need to don oxygen masks in the event of decompression. The aural alert must activate concurrently with the deployment of the oxygen masks in the main passenger cabin and must be loud enough to be heard and clearly understood from each suite berth and seat location.

c. When an occupant needs to locate and don a deployed oxygen mask, sufficient levels of lighting to perform this task must be automatically activated within the suite.

d. Automatic presentation of oxygen for occupants lying in the berth.

e. If a chemical oxygen generator is used as the oxygen supply source, the suite oxygen installation must meet §§ 25.795(d) and 25.1450 at amendment 25-138 or higher.

2. The design approval holder must provide operating procedures to move suite occupants when smoke is present, or firefighting is occurring near or in the suites, for incorporation into the operator's training programs and appropriate operational manuals:

a. A limitation must be included in the airplane flight manual (AFM) requiring that crewmembers be trained in the operating procedures related to the suites.

3. The design of each suite, and the location of the firefighting equipment where suites are installed, must allow the crewmembers to conduct effective firefighting in the suite. For a manual, hand-held extinguishing system (designed as the sole means to fight a fire) for the suite:

a. A limitation must be included in the AFM requiring that crewmembers be trained in the firefighting procedures.

b. Each suite design must allow crewmembers equipped for firefighting to have unrestricted access to all parts of the suite compartment.

4. Approved procedures describing the methods for searching the suite compartment for fire sources must be established. These procedures should include a drawing or photo clearly indicating the location of the stowage drawer and other potential sources of smoke ( e.g., the monitor). They must be transmitted to the operator for incorporation into their training programs and appropriate operations manuals.

5. If a berth is installed, occupancy of each suite is limited to a single passenger.

a. Each berth installed in the suite must incorporate a safety belt that meets § 25.785(f).

b. Each berth must be placarded to indicate the appropriate orientation of the occupant's head direction.

c. Each berth cushion must meet § 25.853(c).

6. If waste-disposal receptacles are fitted in the suite, the suite must be equipped with an automatic fire-extinguishing system that meets the performance requirements of § 25.854(b).

7. The design of each suite must:

a. Maintain minimum main aisle(s), cross aisle(s), and passageway(s) required by 14 CFR part 25 requirements when subjected to the ultimate inertia forces listed in § 25.561(d).

b. Prevent structural failure or deformation of components that could block access to the available evacuation routes ( e.g., seats, doors, contents of stowage compartments, etc.).

8. In addition to the requirements of § 25.562 for seat systems, which are occupiable during taxi, takeoff, and landing, the suite structure must be designed for the additional loads imposed by the seats as a result of the conditions specified in § 25.562(b).

Mortgagees seeking to originate a Federal Housing Administration (FHA)-insured mortgage regulated pursuant to 24 CFR part 200, subpart A, must comply with the project completion funding requirements in 24 CFR 200.54. These require that a mortgagor deposit funds with its mortgagee that are sufficient, when added to the proceeds from the FHA-insured mortgage, to assure completion of planned multifamily or healthcare facility project work and to pay the initial service charge, carrying charges, and legal and organization expenses incident to the construction of the project. Typically, 24 CFR 200.54(b) requires that the funds deposited by the mortgagor with the mortgagee (mortgagor-provided funds) must be disbursed in full for project work, material, and incidental charges and expenses (collectively, “project-related expenses”) before the mortgagee may disburse any mortgage proceeds. HUD requires that mortgagees disburse the mortgagor-provided funds in full before disbursing any mortgage proceeds as a basic risk measure. 1

For most mortgages regulated pursuant to 24 CFR part 200, subpart A, the mortgagor-provided funds are disbursed in full to pay for project-related expenses with the initial advance of the insured mortgage proceeds at the time the insured mortgage is endorsed. For certain mortgages, however, the amount of mortgagor-provided funds exceeds the amount of project-related expenses due at the time the insured mortgage is endorsed. Where the mortgagor-provided funds are not fully disbursed at the time the insured mortgage is endorsed, the mortgagor-provided funds are fully disbursed through subsequent disbursements by the mortgagee, usually with the mortgagor-provided funds being disbursed within two months after the insured mortgage is endorsed.

Given that 24 CFR 200.54(b) does not permit insured mortgage proceeds to be disbursed until the mortgagee disburses all mortgagor-provided funds, if the mortgagor-provided funds are not fully disbursed at the time the insured mortgage is endorsed, the mortgage cannot be pooled into a mortgage-backed security (MBS) guaranteed by the Government National Mortgage Association (Ginnie Mae) without conflicting with 24 CFR 200.54(b). 2 As such, for an insured mortgage to be pooled into a Ginnie Mae guaranteed MBS, the insured mortgage proceeds must be permitted to be disbursed.

This conflict with 24 CFR 200.54(b) typically only exists for a short period of usually no longer than two months after the endorsement of the FHA-insured mortgage, by which time the mortgagor-provided funds are usually fully disbursed. During the short period where this conflict exists, the mortgagee must either implement unusual and burdensome mortgage servicing practices to maintain compliance with 24 CFR 200.54(b) or else the mortgagee will not be able to pool the insured mortgage into a Ginnie Mae guaranteed MBS at the time of endorsement. If a mortgagee is unable to pool an insured mortgage into a Ginnie Mae guaranteed MBS at endorsement, the mortgagee might never be able to securitize the insured mortgage and might fail to meet contractually required delivery dates between the mortgagee and investor. This could potentially lead to costly investor compensation fees. The mortgagee may also experience issues relating to its financial liquidity cycle. When many insured mortgages are unable to be pooled into Ginnie Mae guaranteed MBSs at the time the insured mortgages are endorsed, cascading issues for the broader mortgage market can occur. These can include reducing the overall liquidity of the mortgage market and increasing the cost on mortgagors to borrow funds, which reduces the availability of housing and ultimately harms HUD's mission to create strong, sustainable, inclusive communities and affordable homes for all.

HUD has recently addressed the described conflict with the requirements in 24 CFR 200.54(b) for mortgages insured under National Housing Act sections 213 and 221(d)(4) by issuing a partial regulatory waiver of the requirements of 24 CFR 200.54(b) (Partial Waiver of 24 CFR 200.54(b)). 3 The Partial Waiver of 24 CFR 200.54(b) partially waived the requirement in 24 CFR 200.54(b) that mortgagor-provided funds “must be disbursed in full” for project-related expenses before any disbursement of funds from the insured mortgage. Instead, the Partial Waiver of 24 CFR 200.54(b) permitted, to the extent necessary, a mortgagee to disburse funds from the insured mortgage in an amount up to one-half percent (0.5%) of the initially endorsed mortgage amount. The Partial Waiver of 24 CFR 200.54(b) allows mortgagees to pool insured mortgages into Ginnie Mae guaranteed MBSs when mortgagor-provided funds are not fully disbursed at the time the insured mortgage is endorsed because it allows mortgagees to meet the Ginnie Mae requirement that the insured mortgage proceeds be disbursable.

Through this proposed rule, HUD proposes to add an exception to the requirement in 24 CFR 200.54(b) that the funds provided by the mortgagor must be disbursed in full before the disbursement of any proceeds from the insured mortgage. This proposed rule would also make non-substantive terminology and organizational edits to 24 CFR 200.54 that would not affect any other requirements within the section.

The exception proposed to be added to 24 CFR 200.54(b) would permit mortgagees, where the funds provided by the mortgagor are not fully disbursed with the initial advance of the insured mortgage proceeds, to disburse up to 1 percent of the mortgage amount initially endorsed for insurance before requiring that the funds provided by the mortgagor be disbursed in full. This proposed exception would permit that a mortgagee could disburse mortgage proceeds at the time the mortgage is initially endorsed for insurance up to a maximum of 1 percent of the initially endorsed mortgage amount. Alternatively, a mortgagee could choose to disburse mortgage proceeds in any amount on a monthly basis, whether consecutive or not, up to a combined maximum of 1 percent of the initially endorsed insured mortgage amount until the mortgagor-provided funds are fully disbursed.

As described in the Background section of this proposed rule, the Partial Waiver of 24 CFR 200.54(b) permits a mortgagee to disburse funds from the insured mortgage in an amount up to one-half percent (0.5%) of the initially endorsed mortgage amount. HUD is proposing to set the amount of the proposed exception to 24 CFR 200.54(b) at 1 percent of the initially endorsed mortgage amount because in an environment where mortgage interest rates increase, additional mortgagor-provided funds are required to be deposited with the mortgagee. Where additional mortgagor-provided funds are deposited with a mortgagee, there is an increased chance that the mortgagor-provided funds will not be fully disbursed when the insured mortgage is initially endorsed. Permitting a 1% of the initially endorsed mortgage amount exception to 24 CFR 200.54(b) will allow additional mortgages to be securitized at the time of endorsement with no incremental risk to HUD compared to the one-half percent (0.5%) prescribed in the Partial Waiver of 24 CFR 200.54(b).

The proposed exception to 24 CFR 200.54(b) would allow mortgagees to disburse mortgagor-provided funds for project-related expenses in conjunction with the proceeds from the insured mortgage at the time the mortgage is initially endorsed even where the mortgagor-provided funds are not fully disbursed with the initial advance of the insured mortgage proceeds. This would allow mortgagees to pool a mortgage into a Ginnie Mae guaranteed MBS even when the mortgagor-provided funds were not fully disbursed with the initial advance of the insured mortgage proceeds.

This proposed exception would help keep FHA-insured mortgage products competitive in economic environments with rising interest rates and/or multi-year high interest rates, especially for new construction projects, where a higher proportion of mortgage proceeds are constrained by FHA's debt service coverage ratio requirements. In an economic environment with rising and high interest rates, mortgagors must deposit additional funds with their mortgagee, making it more likely that the mortgagor-provided funds will not be fully disbursed during the initial advance of the insured mortgage proceeds. HUD believes that the proposed exception would help ensure that interest rates for FHA-insured mortgages remain competitive and ensure the liquidity of FHA-insured mortgages on the secondary mortgage market.

In determining whether to propose the exception to 24 CFR 200.54(b), HUD considered whether an alternative solution to the proposed exception to 24 CFR 200.54(b) existed that would better address the issue outlined throughout this proposed rule. One alternative solution considered by HUD was to encourage the mortgage industry to contract for the future delivery of MBSs once all mortgagor-provided funds had been disbursed from the insured mortgages that were to be pooled. While this solution could, in theory, correct the same issue that the proposed exception addresses, HUD ultimately determined that this would likely cause higher borrowing costs for mortgagors because interest rates would need to be hedged through some mechanism. Further, mortgagees would potentially experience unfavorable accounting classifications, having to book recently closed mortgages as “mortgages held for sale,” rather than booking closed mortgages as the more favorable “mortgage serving rights.” Mortgagees could also face unfavorable changes to their counterparty credit profile because of the need to hold whole mortgages on their balance sheet for a number of months, likely precluding smaller mortgagees from warehouse credit and potentially creating funding constraints. For these reasons, HUD believes that the proposed exception to 24 CFR 200.54(b) would be a better solution for mortgagors, mortgagees, FHA, and the secondary mortgage markets.

HUD has evaluated the results of granting the Partial Waiver of 24 CFR 200.54(b). At the time that HUD granted the Partial Waiver of 24 CFR 200.54(b), HUD determined that permitting up to one-half percent (.5%) of the initially endorsed mortgage amount to be disbursed represented only a negligible increase of risk to FHA. As expected, since granting the Partial Waiver of 24 CFR 200.54(b) in July 2021, HUD has received positive feedback from mortgagees regarding the use of the partial waiver and FHA has experienced no negative impacts due to mortgagees' reliance on the partial waiver.

In reviewing the knowledge gained from the implementation of the Partial Waiver of 24 CFR 200.54(b), HUD designed this proposed rule to be similar to the partial waiver, with a notable exception being that this proposed rule permits mortgagees to disburse mortgage proceeds in an amount up to 1 percent, rather than one-half percent, of the initially endorsed mortgage amount before requiring that the mortgagor-provided funds be disbursed in full. HUD determined that the proposed 1 percent of the initially endorsed mortgage amount produces no meaningful increase of risk to FHA, while better helping to ensure that mortgagees are more easily able to pool mortgages into Ginnie Mae guaranteed MBSs.

In summary, HUD believes that the proposed exception to 24 CFR 200.54(b) is the best solution to the potential conflict with the requirements in 24 CFR 200.54(b) where the mortgagor-provided funds are not fully disbursed with the initial advance of the insured mortgage proceeds for mortgages intended to be pooled into Ginnie Mae guaranteed MBSs. The proposed exception would assist FHA in keeping its mortgage products competitive and would further HUD's mission to create strong, sustainable, inclusive communities and affordable homes for all.

Pursuant to Executive Order 12866 (Regulatory Planning and Review), a determination must be made whether a regulatory action is significant and therefore, subject to review by the Office of Management and Budget (OMB) in accordance with the requirements of the Executive Order. Executive Order 13563 (Improving Regulations and Regulatory Review) emphasizes the importance of quantifying both costs and benefits, reducing costs, harmonizing rules, and promoting flexibility. The order also directs Executive agencies to analyze regulations that are “outmoded, ineffective, insufficient, or excessively burdensome, and to modify, streamline, expand, or repeal them in accordance with what has been learned.” Executive Order 13563 further directs that, where relevant, feasible, and consistent with regulatory objectives, and to the extent permitted by law, agencies are to identify and consider regulatory approaches that reduce burdens and maintain flexibility and freedom of choice for the public. Executive Order 14094 (Modernizing Regulatory Review) amends section 3(f) of Executive Order 12866, among other things.

As discussed in this preamble, the only substantive regulatory change proposed in this rule would permit mortgagees, where the funds provided by the mortgagor are not fully disbursed with the initial advance of the insured mortgage proceeds, to disburse up to 1 percent of the mortgage amount initially endorsed for insurance before requiring that the funds provided by the mortgagor be disbursed in full. This rule was determined not to be a “significant regulatory action” as defined in section 3(f) of Executive Order 12866 as amended by Executive Order 14094 and is not an economically significant regulatory action and therefore was not subject to OMB review.

The Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et seq. ) generally requires an agency to conduct a regulatory flexibility analysis of any rule subject to notice and comment rulemaking requirements, unless the agency certifies that the rule will not have a significant economic impact on a substantial number of small entities. The changes proposed in this rule are limited to permitting mortgagees, where the funds provided by the mortgagor are not fully disbursed with the initial advance of the insured mortgage proceeds, to disburse up to 1 percent of the mortgage amount initially endorsed for insurance before requiring that the funds provided by the mortgagor be disbursed in full. These proposed changes would not have a significant economic impact on a substantial number of small entities. Accordingly, the undersigned certifies that the proposed rule will not have a significant economic impact on a substantial number of small entities.

Notwithstanding HUD's determination that this rule will not have a significant impact on a substantial number of small entities, HUD specifically invites comments regarding any less burdensome alternatives to this rule that will meet HUD's objectives as described in the preamble to this rule.

Executive Order 13132 (Federalism) prohibits an agency from publishing any rule that has federalism implications if the rule either imposes substantial direct compliance costs on State and local governments and is not required by statute or preempts State law, unless the agency meets the consultation and funding requirements of section 6 of the Executive Order. This proposed rule does not have federalism implications and does not impose substantial direct compliance costs on State and local governments or preempt State law within the meaning of the Executive Order.

A Finding of No Significant Impact with respect to the environment has been made in accordance with HUD regulations at 24 CFR part 50, which implement section 102(2)(C) of the National Environmental Policy Act of 1969 (42 U.S.C. 4332(2)(C)). The Finding of No Significant Impact is available for public inspection on www.regulations.gov and between the hours of 8 a.m. and 5 p.m. weekdays in the Regulations Division, Office of General Counsel, Room 10276, Department of Housing and Urban Development, 451 7th Street SW, Washington, DC 20410-0500.

Title II of the Unfunded Mandates Reform Act of 1995 (2 U.S.C. 1531-1538) (UMRA) establishes requirements for Federal agencies to assess the effects of their regulatory actions on State, local, and Tribal governments, and on the private sector. This proposed rule would not impose any Federal mandates on any State, local, or Tribal governments, or on the private sector, within the meaning of the UMRA.

For the reasons stated above, HUD proposes to amend 24 CFR part 200 as follows:

The addition reads as follows:

All submitted comments and attachments are part of the public record and subject to disclosure. Do not enclose any material in your comments that you consider to be confidential or inappropriate for public disclosure.

Ancillary service endorsements provide an option for mailers to instruct the Postal Service on how to treat their mail if it is determined to be undeliverable-as-addressed and to request address correction services. Address corrections are currently available in four available formats: a returned mailpiece with the new address or reason for nondelivery attached; PS Form 3547, Notice to Mailer of Correction in Address, that is mailed to the return address on a mailpiece; PS Form 3579, Notice of Undeliverable Periodical, mailed to the publisher address indicated in the publication ID Statement; or via ACS TM (Address Change Service) which is an electronic address correction notice made available to the sender via download from a secure USPS website that requires a login and password to access the files. Address correction fees are charged based on the method in which they are provided, with return mail costs and manual address correction fees that reflect the USPS costs to handle those notices.

The IMpb applied to packages allows shippers to obtain postage discounts and the ability to track their packages through the Postal network. The Postal Service can effectively provide address correction notices to our IMpb mailers electronically via ACS faster and more efficiently.

The Postal Service is proposing to remove the option to request PS Forms 3547, Notice to Mailer of Correction in Address, and PS Form 3579, Notice of Undeliverable Periodical, for packages with an IMpb.

IMpb mailers that desire address correction information from undeliverable as addressed (UAA) mail will be required to receive address correction notices electronically via ACS. IMpb mailers will have to sign up for IMpb ACS or Traditional ACS.

The Postal Service is proposing to implement this change effective March 5, 2025. However, mailers may begin to request ACS immediately. We believe this proposed revision will provide customers with more efficient and less costly address correction notices.

Although exempt from the notice and comment requirements of the Administrative Procedure Act (5 U.S.C. 553(b), (c)) regarding proposed rulemaking by 39 U.S.C. 410(a), the Postal Service invites public comment on the proposed revisions to Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM), incorporated by reference in the Code of Federal Regulations.

We will publish an appropriate amendment to 39 CFR part 111 to reflect these changes.

Accordingly, the Postal Service proposes to amend 39 CFR part 111 as follows:

On July 19, 2024, the EPA published the proposed rule “Approval and Promulgation of Air Quality Implementation Plans; Connecticut; Regional Haze State Implementation Plan for the Second Implementation” in the Federal Register (89 FR 58663). The original deadline to submit comments was August 19, 2024. This action extends the comment period; written comments must now be received by August 26, 2024.

Throughout this document wherever “we,” “us,” or “our” is used, we mean the EPA.

As explained below, EPA is proposing to approve and conditionally approve various Colorado SIP provisions with respect to the adequacy of reporting requirements that the State resubmitted on May 3, 2024. These provisions were part of SIP submittals originally submitted by Colorado on May 14, 2018; May 13, 2020; March 22, 2021; and May 20, 2022, to address RACT requirements for purposes of the 2008 ozone NAAQS. EPA previously finalized approvals, conditional approvals, limited approvals, limited disapprovals, and disapprovals of different portions of these submittals on May 9, 2023;  1 November 7, 2023;  2 and December 8, 2023. 3 As relevant to today's proposal, EPA previously issued a limited approval/limited disapproval of certain SIP provisions, with the limited disapproval portion applicable to the adequacy of the reporting requirements associated with those provisions in the May 9, 2023 action. 4

On May 3, 2024, the State of Colorado resubmitted portions of the prior SIP submissions that were the subject of the limited disapproval and also submitted a letter committing to undertake additional steps to improve public access to regulatory compliance information and clarify existing SIP reporting requirements (Commitment Letter). 5 Based on the additional information described in this letter, EPA is now proposing to approve Colorado's Reg. 7 and Reg. 21 with respect to the adequacy of reporting requirements for storage tank emission controls, storage tank and wet seal centrifugal compressor control device testing, consumer products, and architectural and industrial maintenance (AIM) coatings. EPA is basing its proposed approval on the additional information and clarification that the State provided concerning the existing reporting requirements that apply to them. Based on the additional information and commitments by the State to make additional revisions, EPA is also proposing to conditionally approve the adequacy of reporting requirements for metal parts and metal products coatings, wood products coatings, combustion equipment at major sources, and foam manufacturing. This proposed conditional approval is based on the State's commitment to make further revisions to the reporting requirements for these specific rules, and to submit those revisions to EPA for approval into the SIP, to address the deficiencies identified in the May 9, 2023 rulemaking that were the basis for the limited disapproval. 6

Under section 110(k)(4) of the CAA, the EPA may conditionally approve a SIP submission based on a commitment from a state to adopt specific enforceable measures by a date certain no later than one year from the date of approval of the plan revision. 7 If EPA finalizes the proposed conditional approval of the identified Reg. 7 rules, the State must meet its commitment to submit the necessary SIP revisions to EPA by May 31, 2025. 8 If the State fails to do so, this conditional approval action would automatically become a disapproval on that date. If the State submits timely SIP revisions but EPA finds the SIP submittal to be incomplete, this conditional approval action would become a disapproval on the date of EPA's incompleteness finding. In either case, EPA would notify the State by letter that the conditional approval has converted to a disapproval. The EPA subsequently would publish a document in the Federal Register notifying the public that the conditional approval was converted to a disapproval. EPA notes that the provisions that we are proposing to conditionally approve are already part of the SIP due to our May 9, 2023 limited approval. Thus, in the event the conditional approval is converted to a disapproval, the underlying SIP provisions that were the subject of the prior limited approval/limited disapproval would remain in the SIP, but the prior limited disapproval of those provisions with respect to the adequacy of reporting requirements would return.

If we finalize this rulemaking as proposed, Colorado will have corrected some of the deficiencies identified in our May 9, 2023 limited disapproval, and committed to correct the remaining deficiencies as described in its Commitment Letter. We are concurrently making an interim final determination to defer application of CAA section 179 sanctions associated with our May 9, 2023 limited disapproval. Consistent with applicable sanction regulations, 9 EPA will be making the interim final determination based on this proposal to approve and conditionally approve SIP revisions from Colorado to resolve the deficiencies that were the basis of our prior limited disapproval that triggered sanctions. If this conditional approval converts to a disapproval due to the State's failure to meet its commitment, then the offset sanction under CAA section 179(b)(2) would apply in the affected area on the later of: (1) the date when the approval becomes a disapproval or EPA issues such a proposed or final disapproval, whichever is applicable; or (2) December 9, 2024 ( i.e. 18 months from the finding that started the original sanctions clock). 10 Subsequently, the highway sanction under section 179(b)(1) would apply in the affected area six months after the date the offset sanction applies. 11

The basis for our proposed action is discussed in this proposed rulemaking. Technical information that we are relying on, as well as the State's Commitment Letter, are in the docket, available at https://www.regulations.gov, Docket ID No. EPA-R08-OAR-2024-0225.

On March 12, 2008, EPA revised both the primary and secondary NAAQS for ozone to a level of 0.075 parts per million (ppm) (based on the annual fourth-highest daily maximum 8-hour average concentration, averaged over 3 years), to provide increased protection of public health and the environment. 12 The 2008 ozone NAAQS retains the same general form and averaging time as the 0.08 ppm NAAQS set in 1997, but is set at a more protective level. Specifically, the 2008 8-hour ozone NAAQS is attained when the 3-year average of the annual fourth-highest daily maximum 8-hour average ambient air quality ozone concentrations is less than or equal to 0.075 ppm. 13 Effective July 20, 2012, EPA designated any area that was violating the 2008 8-hour ozone NAAQS based on the three most recent years (2008-2010) of air monitoring data as nonattainment. 14 In that action, EPA designated the Denver Metro/North Front Range (DMNFR) Area as nonattainment and classified the area as Marginal. 15 Ozone nonattainment areas are classified based on the severity of their ozone levels, as determined using the area's design value. The design value is the 3-year average of the annual fourth-highest daily maximum 8-hour average ozone concentration at a monitoring site. 16 States with areas designated as nonattainment and classified as Marginal were required to attain the 2008 8-hour ozone NAAQS no later than July 20, 2015, based on 2012-2014 monitoring data. 17

On May 4, 2016, EPA published its determination that the DMNFR Area, among other areas, had failed to attain the 2008 8-hour ozone NAAQS by the applicable Marginal area attainment deadline, and accordingly reclassified the area as Moderate. 18 Colorado submitted SIP revisions to the EPA on May 31, 2017, to meet the requirements for the Moderate classification in the DMNFR Area. 19 Among the requirements for Moderate areas, states must submit SIP provisions to impose RACT level controls on relevant emission sources in the nonattainment area. EPA took final action approving the majority of the May 31, 2017 submittal on July 3, 2018, but deferred action on portions of the Reg. 7 rules submitted by the state to meet RACT requirements. 20 On February 24, 2021, EPA took final action approving additional measures as addressing Colorado's RACT obligations for Moderate nonattainment areas. 21 States with nonattainment areas classified as Moderate were required to attain the 2008 8-hour ozone NAAQS no later than July 20, 2018, based on 2015-2017 monitoring data. 22 On December 26, 2019, EPA published its determination that the DMNFR Area, among other areas, had failed to attain the 2008 8-hour ozone NAAQS by the applicable attainment deadline for Moderate areas, and accordingly reclassified the area as Serious. 23

On May 9, 2023, EPA took final action approving portions of the 2008 8-hour ozone Serious area attainment plan for the DMNFR Area submitted by the State of Colorado on March 22, 2021, and portions of additional SIP submissions made by the State related to those requirements on May 8, 2019, May 13, 2020, March 22, 2021, May 18, 2021, and May 20, 2022. 24 The State made these SIP submissions to meet Serious ozone nonattainment plan requirements for the DMNFR Area, to address RACT requirements for certain source categories in the DMNFR Area, and to adopt volatile organic compounds (VOC) standards for consumer products and architectural and industrial maintenance coatings. In the May 9, 2023 action, EPA also finalized a limited approval and limited disapproval of parts of the SIP submissions made on May 14, 2018, May 13, 2020, March 22, 2021, May 18, 2021, and May 20, 2022, with respect to certain RACT categories, 25 and finalized a limited conditional approval and limited disapproval of specific provisions intended to meet RACT requirements. 26

The limited disapproval portions of the May 9, 2023 final rule resulted from the Agency's determination that although the rules met RACT requirements with respect to stringency, they lacked adequate periodic reporting requirements as required under the CAA and EPA regulations. Section 110 of the CAA includes several subsections requiring that a state's SIP provisions be enforceable, and that states require reporting from sources. Under section 110(a)(2)(A), state SIPs must “include enforceable emission limitations and other control measures, means, or techniques * * * as may be necessary or appropriate to meet the applicable requirements of this chapter.” Further, section 110(a)(2)(C) requires SIPs to “include a program to provide for the enforcement of the measures described in subparagraph (A).”

Typically, a primary mechanism for ensuring that a SIP provision is legally and practicably enforceable is for a state to impose sufficient monitoring, recordkeeping, and reporting (MRR) requirements on affected sources. Section 110(a)(2)(F)(ii) speaks more explicitly to source reporting by requiring SIPs to “require periodic reports on the nature and amounts of emissions and emissions-related data,” as may be prescribed by EPA. EPA has promulgated regulations implementing section 110(a)(2)(F) requirements at 40 CFR 51.211(a), which requires state SIPs to provide for periodic reports to the state on the nature and amount of emissions from stationary sources. EPA notes that reporting requirements serve multiple purposes, including promoting transparency, providing deterrence against violations, and supporting effective enforcement of SIP requirements. A lack of adequate reporting requirements can undermine citizens' ability to participate in the enforcement of the SIP as authorized and provided for in CAA section 304. As explained in our May 9, 2023 action, EPA concluded that the rules subject to the limited disapproval did not “include sufficient reporting requirements to ensure that citizens will be able to enforce the SIP requirements, as is necessary under the CAA and EPA regulations.”  27

On July 10, 2023, the State submitted a Petition for Reconsideration asking EPA to reconsider the limited disapproval portions of the May 9, 2023 final rule. EPA responded to the Petition for Reconsideration in a letter dated August 31, 2023, informing the State that EPA was granting the petition as to the limited disapproval portions of the May 9, 2023 final rule. 28 Since granting the petition for reconsideration, EPA has offered Colorado the opportunity to explain more fully how the State's regulations provide for adequate reporting, to inform EPA of various actions taken by the Colorado Air Pollution Control Division (Division) to enhance access to public records and information, and to consider what changes to existing regulations would improve reporting requirements to address deficiencies. As a result of these discussions, Colorado has resubmitted Reg. 7 and Reg. 21 with additional explanations to support proposed approval of some provisions and a commitment to make changes to support proposed conditional approval of others.

In this action, we are evaluating Colorado's May 3, 2024 SIP submittal intended to address reporting requirements in response to the May 9, 2023 limited disapproval. In this submittal, the State explained why some of the SIP provisions subject to the limited disapproval have adequate reporting requirements, and made a commitment to add reporting requirements for the other SIP provisions subject to the limited disapproval. The portions of the original SIP submittals that the State has resubmitted for EPA's evaluation with respect to reporting requirements are described below.

This submittal contained amendments to Reg. 7, sections XII. (Volatile Organic Compound Emissions from Oil and Gas Operations) and XVIII. (Natural Gas-Actuated Pneumatic Controllers Associated with Oil and Gas Operations) to implement RACT for oil and gas sources covered by the EPA's 2016 Oil and Gas Control Techniques Guidelines (CTG). 29 We previously acted on this SIP submittal, 30 which included finalizing a limited disapproval of Reg. 7, section XII.J.1., concerning centrifugal compressors.

On May 13, 2020, the State made two SIP submittals. One of the submittals included a full reorganization of Reg. 7 into parts A-E, amended oil and gas storage tank requirements, updated RACT requirements for major sources of VOC and nitrogen oxides (NO X ) in the DMNFR Area, updated requirements for gasoline transport truck testing and vapor control systems, and included typographical, grammatical, and formatting corrections throughout. We previously acted on this SIP submittal, 31 including finalizing a limited disapproval of Reg. 7, part D, sections I.D., I.E., and I.F. concerning storage tanks and section I.J.1. concerning centrifugal compressors.

The second submittal contained a new Reg. 21 to limit the VOC content in consumer products and in AIM coatings manufactured, distributed, or sold in the DMNFR Area. Specifically, this rule adopted VOC standards in the Ozone Transport Commission (OTC) AIM coatings model rule phase 2 (2014) and VOC standards in the OTC consumer products model rule phase 4 (2013). Reg. 21 included definitions, exemptions, labeling, and recordkeeping provisions based on the OTC model rules. We previously acted on this SIP submittal, 32 including a limited disapproval of Reg. 21, parts A and B.

This submittal contained the State's Serious ozone attainment plan and revisions to Reg. 7 to include RACT requirements in Colorado's ozone SIP for major sources that emit 50 tons per year (tpy) or more of VOC and/or NO X . The Reg. 7 revisions included expanding categorical requirements to reduce VOC emissions related to wood surface coatings in part C, section I.O.; adding NO X emission limits for turbines, boilers, and landfill or biogas engines in part E, section II.; and adding categorical requirements to reduce VOC emissions related to foam manufacturing in part E, section V. The State also made non-substantive typographical, grammatical, and formatting corrections to Reg. 7. We previously acted on this SIP submittal, 33 including a limited approval/limited disapproval of Reg. 7, part C, section I.O. concerning wood products coatings and part E, sections II.A. and V. concerning RACT rules for combustion equipment and foam manufacturing. The limited disapproval was only with respect to the adequacy of source reporting requirements.

One of the State's May 20, 2022 submittals contained amendments to Reg. 7 that establish categorical RACT requirements for major sources of NO X and sources covered by the miscellaneous metal parts coatings CTG in the DMNFR Area. Specifically, on July 16, 2021, the AQCC adopted RACT requirements in part C, section I. for miscellaneous metal parts coatings and part E, section II. RACT requirements for process heaters at major sources of NO X emissions. The State also made non-substantive typographical, grammatical, and formatting corrections to Reg. 7.

The other May 20, 2022 submittal contained revisions concerning RACT requirements for oil and gas sources. Specifically, on December 17, 2021, the AQCC adopted revisions to Reg. 7, part D, section I. for performance or manufacturer testing for combustion equipment used to control emissions from storage vessels and wet seal centrifugal compressors.

We previously acted on these May 20, 2022 SIP submittals, 34 including a limited approval/limited disapproval of Reg. 7, part C, section I.L. pertaining to metal parts and product coatings; part D, sections I.E. and I.J. pertaining to inspections of and performance testing for storage tanks and centrifugal compressors; and part E, section II. pertaining to combustion equipment rules. The limited disapproval was only with respect to the adequacy of source reporting requirements.

The CAA requires that states meet certain procedural requirements before submitting a SIP submittal to the EPA, including the requirement that states adopt SIP revisions after reasonable notice and public hearing. 35 In our November 9, 2022 proposed and May 9, 2023 final actions, we determined that Colorado had satisfied this requirement with respect to the SIP provisions that the State has resubmitted again for consideration here. For additional background, see the November 9, 2022 proposed and May 9, 2023 final rules. We had previously acted on the State's May 14, 2018; May 13, 2020; March 22, 2021; and May 20, 2022 submittals, but in this action, EPA is evaluating Colorado's May 3, 2024 SIP submittal intended to address reporting requirements in response to the May 9, 2023 limited disapproval. In this submission, the State has resubmitted the SIP provisions described above, explained why it has adequate reporting requirements for some of those SIP provisions, and made a commitment to add reporting requirements for the other SIP provisions.

In this proposed action, we are evaluating Colorado's May 3, 2024 SIP submittal, which was intended to address reporting requirements in response to the May 9, 2023 limited disapproval, for the limited purpose of considering whether the submitted SIP provisions include reporting requirements that are adequate to comply with relevant requirements of CAA section 110 (as outlined in section II. of this document) and EPA regulations at 40 CFR 51.211(a). This consideration includes assessing whether the reporting requirements are sufficient to make the submitted SIP provisions legally and practicably enforceable by citizens.

Our proposed approval and conditional approval of the respective SIP provisions in today's action does not otherwise alter our previous determination that these rules implement RACT with respect to the sources covered by the rules, but for the specified deficiencies in reporting requirements identified in the limited disapproval. We are taking comment on today's proposal for 30 days. Any comments on this proposal should address only our proposed approval and conditional approval with respect to reporting requirements.

In the May 9, 2023 limited disapproval, we noted that the provisions at issue only required facilities to provide records to the state upon request of the state. In other words, these rules did not require sources to make any other periodic report related to compliance with the applicable provisions. We determined that this is inconsistent with CAA and regulatory requirements and undermines citizen enforceability of the specified rules. To address EPA's limited disapproval with respect to the absence of periodic reporting requirements, Colorado submitted a commitment letter to EPA on May 3, 2024. The Commitment Letter describes the process the State undertook to identify existing adequate reporting requirements for some of the SIP provisions subject to the limited disapproval, as well as a commitment to add adequate reporting provisions to the other SIP provisions subject to the limited disapproval. In this action, we are proposing to determine that the State has provided adequate information and made the requisite commitments to make further changes to its rules that would ensure compliance with the relevant CAA provisions under section 110 and EPA regulations, and to allow for citizen enforceability of these rules under CAA section 304, so long as the State fulfills its commitments as described in the Commitment Letter.

In evaluating what additional revisions might be appropriate to address EPA's limited disapproval, Colorado focused on three concepts to ensure public access to information necessary to evaluate compliance with SIP emission limitations: (1) the frequency of reporting; (2) the content of the information reported; and (3) public access to the reported information. More specifically, Colorado focused on three questions: (1) does the SIP require sources to report information necessary to evaluate compliance on a periodic basis?; (2) is the content of the information reported sufficient for a member of the public to evaluate whether the source is in compliance with applicable SIP emission limits?; and (3) can a member of the public access the requisite reported information? In general, EPA agrees with Colorado's approach of considering the three concepts of frequency, content, and public access to the information, as a useful approach to assess reporting requirements, based on the facts and circumstances related to a given SIP provision, such as the affected sources, form of the emission limitation, and other relevant considerations. Based upon EPA's evaluation of Colorado's May 3, 2024 SIP submission, which includes additional information submitted by the State and Colorado's commitment to revise certain rules, we are now proposing to approve some of the SIP provisions and to conditionally approve the other SIP provisions that were previously subject to the limited disapproval, as described below.

Reg. 7, part C, section I. contains rules for surface coating operations. 36 Section I.L. includes metal parts and metal products rules and applies to major and minor sources of VOC in the DMNFR Area. The rules require sources to use products that comply with VOC content limits listed in tables 1 and 2 of the regulation. The recordkeeping provisions in Reg. 7, part C., section I.L.5. currently require applicable records to be maintained for five years and made available to the Division upon request.

In its May 3, 2024 letter, the State clarifies that at least every five years, sources subject to metal parts and product rules must submit Air Pollution Emission Notices (APENs) that include records of the products used by the source. SIP-approved Reg. 3, part A, section II. requires that APENs specify the nature of the facility, process, or activity, and include an estimate of the annual actual emissions, including emission controls. 37 APENs are required for sources in a nonattainment area with uncontrolled actual emissions of criteria pollutants (including the ozone precursors VOC and NO X ) of one ton per year or more, and an affected source must submit them at least once every five years. Revised APENs must also be submitted by sources when various conditions occur, including when a significant change in annual actual emissions occurs, when new control equipment is installed, and when a permit limitation must be modified. Sources subject to section I.L.5. are required to list their most commonly used products on their APENs with enough specificity to enable the public to find the VOC content of those products. APENs are publicly available through the Division's Public Records Portal. 38

In its Commitment Letter, Colorado also expresses concerns about EPA's statement regarding a potential director's discretion issue related to the APEN program in our response to comments in the May 9, 2023 final action. 39 In this document, we clarify that the statement was intended to explain why we did not view the APEN program as sufficient by itself to provide adequate reporting requirements for the relevant rules subject to the limited disapproval. We did not intend to suggest that the APEN program itself creates a problematic director's discretion issue, or that the information required to be submitted through APENs in SIP-approved Reg. 3 is itself problematic. Rather, EPA intended the statement to be specific to the point addressed in that response to comments, and to whether the APEN program could sufficiently address the periodic reporting requirement deficiencies identified in the relevant regulations that resulted in the limited disapproval.

In its Commitment Letter, Colorado provided additional information about the APEN program, and has committed to incorporate additional reporting requirements for the metal parts and metal products source category. In particular, because the APEN list of products used by a source might not be entirely comprehensive and a change in products used might not trigger the submittal of a revised APEN under Reg. 3 (and which therefore might result in the APEN not being updated until the 5-year expiration of the previous notice), Colorado has committed to SIP revisions that will require sources to report information necessary to evaluate compliance on a periodic basis through, at a minimum, annual reports. 40 The content of the information reported through the semi-annual or annual reports will include information on VOC content limits of products used such that the public can access the information necessary to evaluate compliance with the applicable SIP emission limits in section I.L. A member of the public will be able to access the requisite reported information through the Division's Public Records Portal. 41 Accordingly, we are proposing to find that the revisions to which the State has committed would address the deficiencies identified in our May 9, 2023 limited disapproval, and we propose to conditionally approve Reg. 7, part C, section I.L.

Reg. 7, part C., section I.O. includes wood products coating rules applicable to major stationary sources of VOC emissions in the DMNFR Area. 42 The rules require sources to use products that comply with VOC content limits in section I.O.3. The recordkeeping provisions in section I.O.5. require applicable records to be maintained for five years and to be made available to the Division upon request.

In its Commitment Letter, the State clarifies that sources subject to wood products coating rules are subject to requirements for mandatory periodic reporting of certain information under state law for APEN filing requirements and under federal law for Title V reporting, such as deviations from emission limits. Sources must also submit an APEN to the State at least every five years, reporting the products used, among other things. These APENs are publicly available through the Division's Public Records Portal. Nonetheless, to help ensure that the public will be able to sufficiently evaluate whether sources are using products compliant with the VOC content limit in section I.O.3., and to ensure that the information is reasonably current ( i.e., updated more frequently than every 5 years), Colorado has committed to SIP revisions that will require sources to report information necessary to evaluate compliance on a periodic basis through, at a minimum, semi-annual reports. 43 The content of the information reported through the semi-annual reports will include information on VOC content limits of products used such that the public can access the information necessary to evaluate compliance with the applicable SIP emission limits in section I.O. A member of the public will be able to access the requisite reported information through the Division's Public Records Portal. Accordingly, we are proposing to find that the revisions to which the State has committed would address the deficiencies identified in our May 9, 2023 limited disapproval, and we propose to conditionally approve Reg. 7, part C., section I.O.

Reg. 7, part E, section II. includes regulations for combustion equipment located at major sources of NO X emissions in the DMNFR Area. 44 These rules require sources to comply with NO X emission limits and combustion tuning requirements. The recordkeeping provisions in SIP-approved Reg. 7, part E, section II.A.7. require that affected sources keep records for a period of five years and make them available to the Division upon request. Additionally, as the State clarifies in the Commitment Letter, most of the subject combustion equipment is also subject to either continuous emissions monitoring or performance testing requirements, with corresponding reporting of excess emissions and performance testing. For example, the State explains that SIP-approved section II.A.8. requires sources that demonstrate compliance with emission limits in section II.A.4. using continuous emissions monitoring systems (CEMS) or continuous emissions rate monitoring systems (CERMS) to submit quarterly or semi-annual excess emissions reports to the Division. For units demonstrating compliance with section II.A.4 using performance testing, the State explains that sources must submit performance test reports to the Division within 60 days after completion of the performance test program. Under state law and the CAA Title V permitting program, the State further explains that sources are also subject to requirements for periodic reporting of certain information, such as deviations from emissions limitations. This information is publicly available through the Division's Public Records Portal. These specific reporting provisions were not the subject of the EPA limited disapproval. That limited disapproval applied to sources covered by the rule that are subject to combustion process adjustment requirements but did not have associated CEMS/CERMS or performance testing requirements.

To help ensure that members of the public will be able to evaluate compliance with the applicable emissions limitations, particularly with respect to sources not also subject to CEMS/CERMS or performance testing requirements, the State has committed to SIP revisions that will require sources to submit periodic reports containing information necessary to evaluate compliance. 45 The content of the information reported will include information with respect to sources not also subject to continuous monitoring or performance testing such that the public can access the information necessary to evaluate compliance with all of the applicable SIP emission limitations in Reg. 7, part E, section II. A member of the public will be able to access the requisite reported information through the Division's Public Records Portal. Accordingly, we are proposing to find that the revisions to which the State has committed would address the deficiencies identified in our May 9, 2023 limited disapproval, and we propose to conditionally approve Reg. 7, part E, section II.

Reg. 7, part E., section V. includes regulations for foam manufacturing operations located at major sources of VOC emissions in the DMNFR Area. 46 The rules require sources to comply with VOC emission limits in section V.A.4. The recordkeeping provisions in section V.A.7. require that affected sources keep records for a period of five years and make them available to the Division upon request.

The State's Commitment Letter clarifies that these sources are also subject to periodic reporting of certain information, including deviations from emissions limits such as pounds of VOC per material used, under the CAA federal Title V permitting program and state law. Colorado also explains that as to performance tests on emission control equipment that are required in Reg. 7, part E, section V.A.6., subject sources must submit test reports to the Division within 30 days of the performance tests, per SIP-approved requirements in the Common Provisions, 47 and that these reports are publicly available through the Division's Public Records Portal.

To help ensure that members of the public will be able to sufficiently evaluate source compliance with applicable emission limits, the SIP revisions that Colorado has committed to make as described in the Commitment Letter will require sources to report information necessary to evaluate compliance on a periodic basis through semi-annual reports. 48 The content of the information reported through the semi-annual reports will include information on a pounds of VOC per material used basis such that the public can access the information necessary to evaluate compliance with the applicable SIP emission limits in section V. A member of the public will be able to access the requisite reported information through the Division's Public Records Portal. 49 Accordingly, we are proposing to find that the revisions to which the State has committed would address the deficiencies identified in our May 9, 2023 limited disapproval, and we propose to conditionally approve Reg. 7, part E., section V.

Reg. 7, part D., sections I.E. and I.J. include regulations for inspections and performance testing for storage tanks and centrifugal compressors located at major and minor VOC oil and gas exploration and production operations, natural gas compressor stations, and natural gas drip stations in the DMNFR Area. 51 The rules require sources to comply with SIP emission limitations, including combustion efficiency requirements for storage tank controls in I.D.3.a.(i) and performance testing requirements for enclosed combustion devices in sections I.E.3. and I.J.1.h.

The State's Commitment Letter explains how members of the public can obtain information on a periodic basis with the relevant content to evaluate compliance with storage tank emission limitations and any enclosed combustion device testing for the specified tanks or compressors. The State explains that owners or operators of storage tanks must conduct weekly inspections and submit an annual report to the Division with information in section I.F.3.c. to demonstrate compliance with the 95% VOC emission control strategy. 52 The State further explains that this reporting must include a list of all storage tanks controlled pursuant to this rule, the monthly VOC emissions and emission factor, and the control efficiency for air pollution control equipment for each storage tank. Sources must also submit APENs at least every five years for storage tanks with uncontrolled actual VOC emissions equal to or greater than one ton per year. In the APENs, owners or operators report, among other information, actual annual emissions and control device efficiency. These annual reports and APENs are available to the public in the Division's Public Records Portal.

In the Commitment Letter, Colorado also explains that section I.E.3.a. requires owners or operators of storage vessels with the potential for VOC emissions equal to or greater than six tons per year to conduct performance testing of the control device used to reduce emissions at least every five years. Section I.J.1.h. requires that combustion devices used to reduce VOC emissions from wet seal fluid degassing systems on wet seal centrifugal compressors be tested at least every five years. 53 For storage vessels and wet seal centrifugal compressors subject to sections I.E.3.a. and I.J.1.h., the State explains that the federal testing requirements in 40 CFR 60.5413a that Colorado has incorporated by reference into its SIP include periodic reporting requirements. 54 Colorado further explains that these testing requirements include performance testing of control devices used to reduce VOC emissions from storage vessels and wet seal fluid degassing systems on wet seal centrifugal compressors.

Colorado also explains that the provisions in EPA's New Source Performance Standards (NSPS) OOOOa, incorporated into the SIP and applicable to any existing or new storage vessel or wet seal centrifugal compressor subject to the rule, requires owners or operators to submit performance test reports on a periodic basis. Accordingly, based on the additional information and clarification provided by the State in the Commitment Letter that NSPS OOOOa provisions for submitting performance test reports to EPA on a periodic basis have been incorporated into the SIP and that a member of the public will be able to access the requisite reported information through EPA, 55 we are now proposing to approve the provisions in sections I.E. and I.J. with respect to the adequacy of reporting requirements.

Throughout this document whenever “we,” “us,” or “our” is used, we mean the EPA.

Virtual public hearing: The EPA is holding a virtual public hearing to provide interested parties the opportunity to present data, views, or arguments concerning the proposal. The EPA will hold a virtual public hearing to solicit comments on August 21, 2024.

The hearing will convene at 9 a.m. Central Time (CT) and will conclude at 3 p.m. CT. The EPA may close a session 15 minutes after the last pre-registered speaker has testified if there are no additional speakers. The EPA will announce further details, including information on how to register for the virtual public hearing, on the virtual public hearing website at https://www.epa.gov/mo/air-missouri .

The EPA will begin pre-registering speakers and attendees for the hearing upon publication of this document in the Federal Register . To pre-register to attend or speak at the virtual public hearing, please use the online registration form available at https://www.epa.gov/mo/air-missouri, or contact us via email at mcintyre.gerald@epa.gov . The last day to pre-register to speak at the hearing will be August 19, 2024. On August 20, 2024, the EPA will post a general agenda for the hearing that will list pre-registered speakers in approximate order at https://www.epa.gov/mo/air-missouri . Additionally, requests to speak will be taken on the day of the hearing as time allows.

The EPA will make every effort to follow the schedule as closely as possible on the day of the hearing; however, please plan for the hearing to run either ahead of schedule or behind schedule. Each commenter will have approximately 3 to 5 minutes to provide oral testimony. The EPA encourages commenters to provide the EPA with a copy of their oral testimony electronically by including it in the registration form or emailing it to mcintyre.gerald@epa.gov . The EPA may ask clarifying questions during the oral presentations but will not respond to the presentations at that time. Written statements and supporting information submitted during the comment period will be considered with the same weight as oral comments and supporting information presented at the virtual public hearing. A transcript of the virtual public hearing, as well as copies of oral presentations submitted to the EPA, will be included in the docket for this action.

The EPA is asking all hearing attendees to pre-register, even those who do not intend to speak. The EPA will send information on how to join the public hearing to pre-registered attendees and speakers. Please note that any updates made to any aspect of the hearing will be posted online at https://www.epa.gov/mo/air-missouri . While the EPA expects the hearing to go forward as set forth above, please monitor our website or contact us via email at mcintyre.gerald@epa.gov to determine if there are any updates. The EPA does not intend to publish a document in the Federal Register announcing updates.

If you require the services of a translator or a special accommodation such as audio description/closed captioning, please pre-register for the hearing and describe your needs by August 13, 2024. The EPA may not be able to arrange accommodations without advance notice.

Preamble glossary of terms and abbreviations: The following are abbreviations of terms used in the preamble.

On October 1, 2015, the EPA promulgated a revision to the 2015 ozone NAAQS, lowering the level of both the primary and secondary standards to 0.070 parts per million (ppm) for the 8-hour standard. 1 Section 110(a)(1) of the CAA requires States to submit, within three years after promulgation of a new or revised standard, SIP submissions meeting the applicable requirements of section 110(a)(2). 2 One of these applicable requirements is found in CAA section 110(a)(2)(D)(i)(I), otherwise known as the “interstate transport” or “good neighbor” provision, which generally requires SIPs to contain adequate provisions to prohibit in-state emissions activities from having certain adverse air quality effects on other States due to interstate transport of pollution. There are two so-called “prongs” within CAA section 110(a)(2)(D)(i)(I). A SIP for a new or revised NAAQS must contain adequate provisions prohibiting any source or other type of emissions activity within the State from emitting air pollutants in amounts that will significantly contribute to nonattainment of the NAAQS in another State (Prong 1) or interfere with maintenance of the NAAQS in another State (Prong 2). The EPA and States must give independent significance to Prong 1 and Prong 2 when evaluating downwind air quality problems under CAA section 110(a)(2)(D)(i)(I). 3

In this notice of proposed rulemaking, the EPA is providing an opportunity for public comment on its proposed conclusion that the November 1, 2022 SIP submission (hereafter November 2022 Submission or Submission) from Missouri does not contain the necessary provisions to prohibit emissions from sources within the State from significantly contributing to nonattainment or interfering with maintenance of the 2015 ozone NAAQS in downwind areas as required by the CAA. The EPA is proposing to disapprove the November 2022 Submission as to both Prong 1 and 2 of CAA section 110(a)(2)(D)(i)(I) as insufficient on the basis that it fails to adequately support its determination of Missouri's good neighbor obligations for the 2015 ozone NAAQS.

Previously, the EPA disapproved a prior submission provided by the Missouri Department of Natural Resources (MoDNR) to address these obligations. See 88 FR 9336 (February 13, 2023). Following the EPA's proposal to disapprove that submission and proposal for a Federal implementation plan (the proposed Good Neighbor Plan), signed and made public in February and March of 2022, respectively, the MoDNR developed this new Submission. Following review of a draft version of the submission, the EPA advised the MoDNR by letter in fall of 2022 regarding a number of concerns with respect to its approvability. The MoDNR made several adjustments purporting to address the EPA's comments and submitted the Submission as a SIP revision on November 1, 2022, several months after the close of the comment periods on the proposal to disapprove the prior submission and the proposed Good Neighbor Plan.

To evaluate this Submission, the EPA applied its longstanding approach to evaluating good neighbor obligations, the 4-step interstate transport framework (further detailed in section I.D. of this document) that the MoDNR itself used to organize its Submission. The MoDNR specifically worked from the EPA's proposed determinations regarding these obligations by applying the 4-step framework as set forth in the proposed Good Neighbor Plan, 87 FR 20036 (April 6, 2022), while presenting a series of arguments in support of a less stringent set of obligations.

The EPA proposes to find that the MoDNR's November 2022 Submission fails to provide an adequate technical and legal basis to demonstrate that Missouri's good neighbor obligations are adequately addressed, and it unreasonably concludes that only emissions improvements relying on existing control installations at certain identified power plants in the State (which are not, in fact, permanent or enforceable prohibitions, as explained in section III.D.) are sufficient to prohibit Missouri's significant contribution for the 2015 ozone NAAQS. The evidence indicates that additional, cost-effective emissions control opportunities are available across a number of Missouri's large emissions sources and that the MoDNR has not conducted a sufficient review of those emissions control opportunities or its broader source inventory. See section III.C of this document.

The EPA would reach these conclusions regarding this Submission even in the absence of the Good Neighbor Plan; however, the record evidence that the EPA has developed in the course of developing the Good Neighbor Plan provides important information that assists in the evaluation of this Submission. The EPA always strongly encourages States to develop SIP revisions that can replace or forestall the need for FIPs. The EPA explained in the proposed Good Neighbor Plan that States remain free to develop SIP submissions, and consistent with prior good neighbor rulemakings such as the Clean Air Interstate Rule (CAIR) and the Cross-State Air Pollution Rule (CSAPR), the EPA provided States as much information as the Agency could supply at that time to support the ability of States to submit SIP revisions to achieve the emissions reductions that the EPA believed necessary to eliminate significant contribution. Id. at 20040. That proposal could not definitively establish or prejudge the necessary components of an approvable SIP; however, the EPA's discussion there provided notice to Missouri and other States of the EPA's own evidence concerning good neighbor impacts and available controls, and, therefore, the EPA's expected process for reviewing SIPs in light of that evidence. The MoDNR had that information available, and indeed worked from it, at the time it developed the Submission here.

Specifically, in the proposed Good Neighbor Plan, the EPA explained that States may select emissions reductions strategies that differ from the emissions controls included in the proposed FIP. The EPA went on to state that for a State to remove all FIP provisions through an approved SIP revision, a State would need to address all of the required reductions determined through the EPA's own review of the evidence and addressed by the FIP for that State, though the States could go about achieving those reductions differently. Id. at 20149. The EPA also stated in the proposal that if States were to regulate their Electric Generating Units (EGUs), in the case of SIP submissions not adopting the EGU trading program, the EPA would evaluate such a transport SIP based on the particular control strategies selected and whether the strategies as a whole provide adequate and enforceable provisions ensuring that the identified emissions reductions ( i.e., reductions equal to or greater than what the Group 3 trading program will achieve) will be achieved. Id. at 20151. Similarly, for non-Electric Generating Units (non-EGUs), the EPA stated that a State's SIP submission must provide adequate provisions to prohibit an equivalent or greater amount of nitrogen oxide (NO X ) emissions that contribute significantly to nonattainment or interfere with maintenance of the 2015 ozone NAAQS in any other State. Id. 4

The final Good Neighbor Plan signed on March 15, 2023, contained a discussion on SIP submissions similar to the proposal's discussion, which expanded on and clarified certain points in response to comments. There, the EPA reiterated that States remain free to adopt alternative approaches to addressing their significant contribution that differ from the FIP promulgated for that State. However, the EPA stated that, given the Agency's own extensive analysis, it did not anticipate revisiting its findings at Steps 1 or 2 of the transport framework. See 88 FR 36839. Further, the EPA explained that the level of reductions required by the FIP provides an “important benchmark” for States in evaluating possible replacement SIPs, and that we generally anticipated that a SIP seeking an alternative approach to eliminating its significant contributions would need to establish an equivalent level of emissions reductions to what the FIP requires at Step 3, and any such replacement SIP will need to comply with CAA section 110( l ). Id.

The EPA recognizes that the MoDNR made this submission in November of 2022, several months after the proposed Good Neighbor Plan was published, and before the final Good Neighbor Plan was issued on March 15, 2023. The information provided to States regarding what the EPA anticipated would likely be needed to develop a SIP that satisfies the 2015 ozone NAAQS good neighbor obligations stated in the proposal was nonetheless available for the MoDNR to consider in developing this submission. This guidance was also consistent with the EPA's stated policies on approvable good neighbor SIPs across many prior transport rulemakings going back at least to the Clean Air Interstate Rule (CAIR) in 2005. See, e.g., 87 FR 55692, 55693 (September 12, 2022); 86 FR 60602, 60607-08, 60610-11 (November 3, 2021); 86 FR 23054, 23147-48 (April 30, 2021); 81 FR 74504, 74569 (October 26, 2016); 76 FR 48208, 48326-28 (August 8, 2011); 70 FR 25162, 25259-62 (May 12, 2005).

As each of these prior notices make clear, when the EPA is evaluating and acting on SIP submissions following the promulgation of a final transport FIP, the EPA has recognized that the FIP can serve an important purpose in helping the EPA to evaluate the sufficiency of a SIP submission (even when the SIPs were submitted prior to the final FIP). However, the EPA will always carefully evaluate any alternative information or arguments a State puts forward in support of a different understanding of their good neighbor obligations. Thus, in disapproving SIP submissions from New York and New Jersey regarding good neighbor obligations for the 2008 ozone NAAQS, following the promulgation of the Revised CSAPR Update (which had been submitted prior to that rule even being proposed), the EPA explained that neither State had provided “a sufficient demonstration” that the permanent and enforceable measures adopted into the States' SIPs prohibited “significant contribution” in the manner that had been determined in the Revised CSAPR Update, nor “provided an alternative method for doing so.” 86 FR 60607-08, 60610-11.

Similarly here, while the MoDNR has not followed the approach of adopting emissions control measures that are either identical or equivalent to the proposed (or final) Good Neighbor Plan, the EPA continues to recognize that States may submit an alternative approach to meeting their good neighbor obligations, and the EPA will approve such submissions as compliant with the Act's requirements assuming the State has set forth a technically and legally justifiable approach. Consistent with the EPA's approach as discussed in prior rulemakings, the EPA will evaluate such SIP submissions on a case-by-case basis. In the original CSAPR rulemaking, the EPA explained that where States do not adopt the specific control requirements of a Good Neighbor FIP, they still must “provide adequate provisions to prohibit . . . emissions that are determined in the Transport Rule to contribute significantly to nonattainment or interfere with maintenance in another State or States. EPA will review such a SIP on a case-by-case basis.” See, e.g., 76 FR 48328. In the final Good Neighbor Plan, the EPA explained that although there is not a fixed, mass-based emissions budget established for each State in that action, there are other objective metrics that can guide States in developing SIPs. See 88 FR 36842. While the State need not conduct its analysis or select emissions control strategies in a manner identical to the EPA's approach, the end result must nonetheless be adequate to prohibit emissions that significantly contribute to nonattainment and interfere with maintenance.

Further, among the factors the EPA stated in 2018 that it would consider in evaluating alternative approaches is whether consistency in obligations is maintained among States given the “collective contribution” nature of the interstate ozone pollution problem. In a list of “guiding principles” that the EPA identified for States to consider in an appendix to the modeling memorandum issued in March 2018 (see note 14 infra), the EPA noted that consistency among States is “a particularly acute issue with respect to regional transport issues in which multiple States may be implicated.” In addition, the EPA encouraged “collaboration among States linked to a common receptor and among linked upwind and downwind States in developing and applying a regionally consistent approach to identify and implement good neighbor obligations.”

The MoDNR's submission does not reflect any evident collaboration with other States with whom it shares linked receptors, nor with the States in which those receptors are located. The approach the MoDNR set forward in its November 2022 submission would not achieve emissions reductions (or downwind air quality improvements) that are comparable to those the EPA found warranted to address Missouri's good neighbor obligations for the 2015 ozone NAAQS or those of the other States with which Missouri shares common receptor linkages. Nonetheless, the EPA is not proposing to disapprove this Submission simply due to a lack of equivalency with the Good Neighbor Plan. In this proposal, the EPA sets forth a thorough evaluation of all aspects of the MoDNR's November 2022 Submission to determine whether its analytic conclusions and regulatory approach could be technically or legally justified.

The MoDNR's Submission would, if approved, require a minimum level of emissions control performance from certain named EGUs based on the existing NO X -control technologies installed at those units. This bears some similarity to the near-term emissions control strategies that the EPA found appropriate for EGUs in the Good Neighbor Plan for States linked in the 2023 analytic year. However, the EPA has found that the MoDNR's approach achieves fewer emissions reductions than the EPA has found could be cost-effectively achieved in the near term at EGUs in the State, the foregone emissions reductions are not achieved through any other means, and the MoDNR has not justified this alternative level of stringency with respect to these strategies.

Further, even though Missouri remains linked to at least one receptor through the 2026 analytic year in the modeling it relies on in its Submission (notwithstanding the MoDNR's arguments that no such linkages exist in 2026, which the EPA is proposing to disapprove), the MoDNR has not imposed any additional emissions control strategies on its sources that could be implemented by that year. The MoDNR instead argues, using a “dollar-per-ppb” metric, that such reductions are not needed from its sources because they would not be cost-effective. However, setting aside a number of analytic challenges associated with using such a metric, Missouri did not consistently apply this metric within its own Submission nor demonstrate how this metric would apply across other linked upwind States so as to provide an equitable, workable, or consistent standard for defining significant contribution.

The MoDNR further argues that several particular named non-EGU sources in Missouri are already achieving a level of emissions control equivalent to what was proposed for these source types in the proposed Good Neighbor Plan. However, the MoDNR limited its analysis to the provisional list of sources in the proposed Good Neighbor Plan that the EPA was clear was not intended to be definitive, and the MoDNR conducted no comprehensive survey of the non-EGU industrial sources in Missouri. Despite using the proposed Good Neighbor Plan as its information source for identifying these potential emissions control requirements, the MoDNR did not establish that its non-EGU sources are controlled to a level equivalent to Missouri's Good Neighbor Plan FIP (either as finalized or proposed) or that its divergence from the EPA's conclusions was technically supported.

Thus, the November 2022 Submission at times makes technically unsupported departures from the detailed, comprehensive analytical findings in the proposed Good Neighbor Plan (such as the EPA's evaluation of near-term emissions control strategies at EGUs), while at other times unreasonably limits its own analysis solely to the proposed Good Neighbor Plan in areas the EPA was clear were not intended to be definitive considering their analytical purpose (such as the non-EGU screening evaluation).

Finally, the EPA has identified several reasons why the MoDNR's approach using certain “Consent Agreements” with particular named EGU sources is not approvable as the means for implementing those emissions control requirements that the MoDNR concedes would be appropriate to prohibit its significant contribution. Among other issues, these agreements are structured so that they are not yet in effect and will not take effect unless the EPA approves the Submission; however, if the EPA does not “fully approve” the Submission, then the covered sources can unilaterally withdraw from the Agreements. The Agreements additionally provide for their termination at any time by consent of the parties and include broad liability waivers. These provisions fail several important CAA requirements for SIPs, including that emissions reduction measures must be permanent and not subject to modification except through the prescribed processes in the Act.

With this general overview of the MoDNR's Submission in mind, the EPA has identified the following specific aspects of the MoDNR's November 2022 Submission that are inadequate and therefore render the Submission not approvable under CAA section 110(k)(3), because they do not meet the requirements of the good neighbor provision for the 2015 ozone NAAQS:

The EPA is disapproving the November 2022 Submission as a whole because the Agency has not identified any method by which the Submission may be partially approved or approved on a limited or conditional basis. Here, we summarize these bases for disapproval, as guided by our 4-step interstate transport framework (the EPA further explains its framework in section I.D.). The EPA's full evaluation of the November 2022 SIP Submission can be found in section III. of this document.

At Step 2, the EPA proposes to find that the MoDNR did not justify in the November 2022 Submission the use of a 1 ppb or 2 ppb contribution threshold for certain receptors to which it contributes in the 2016v2 modeling, and these same deficiencies in the MoDNR's analysis equally apply to the receptor linkages identified in the 2016v3 modeling. The MoDNR therefore incorrectly concluded that Missouri is not linked ( i.e., “contributing”) to certain receptors in 2023 and no longer linked to any receptors in 2026. (The EPA notes that identical arguments were addressed in the SIP Disapproval Action with respect to Missouri's first SIP submission and in the Good Neighbor Plan, and the EPA is not reopening those determinations in this action.) The EPA is not disapproving the Submission for using the 2016v2 modeling; however, the EPA's analysis is informed by the 2016v3 modeling and the “violating-monitor” maintenance-receptor methodology, which reflects substantial public input obtained through the SIP Disapproval and Good Neighbor Plan rulemakings, improves upon the 2016v2 modeling, and substantiates that Missouri is linked to at least one receptor through the 2026 analytic year.

At Step 3, the EPA proposes to find that the MoDNR conducted an inadequate analysis of its sources' emissions contribution to downwind receptors to determine what amount of those emissions “significantly contribute to nonattainment” or “interfere with maintenance” in the November 2022 Submission. The MoDNR purported to follow the multifactor Step 3 analysis in the proposed Good Neighbor Plan but then identified specific points where it reached alternative conclusions regarding its sources' emissions, thus resulting in the identification of a substantially smaller amount of emissions reduction than the EPA found necessary to eliminate significant contribution in the Good Neighbor Plan. These departures from the EPA's analysis are at odds with the data available to the EPA or are otherwise not adequately justified. The EPA's analysis confirms, consistent with the MoDNR's own methodology using the Air Quality Assessment Tool (AQAT), that the emissions reductions that would be achieved under the November 2022 Submission produce measurably less improvement in ozone levels at the downwind receptors to which Missouri is linked than the Good Neighbor Plan.

With respect to EGUs, the EPA finds that the MoDNR did not adequately explain why additional, near-term, cost-effective emissions reductions were not being required of its EGU sources. Further, the MoDNR did not adequately analyze further emissions control opportunities at its EGU sources or establish why these were not cost-effective. The MoDNR's use of a “dollar-per-ppb” metric to dismiss further emissions reductions from both EGUs and non-EGUs as not cost-effective was not adequately explained and rested on unsubstantiated assertions regarding emissions-control costs and downwind changes in ozone levels. In addition, this metric was applied inconsistently to sources within the State and was not coordinated with the obligations of States that share common receptor linkages with Missouri. The MoDNR's additional analysis of its non-EGU sources was not based on a comprehensive inventory of industrial sources in the State but rather drew from a list of tentatively identified facilities from the EPA's proposed Good Neighbor Plan that the EPA was clear was not intended to be definitive. (The Good Neighbor Plan establishes applicability criteria to define source coverage rather than identifying each covered source by name; it also covers new in addition to existing units meeting those applicability criteria. See 88 FR 36685.) The MoDNR failed to examine whether there was cost-effective emissions control potential across the State's inventory of large non-EGU NO X -emitting sources.

At Step 4, the EPA proposes that even as to those emissions reductions the MoDNR's November 2022 Submission purports to require, it is inadequate to meet g ood neighbor requirements for the 2015 ozone NAAQS and other requirements of the Act. First, the Consent Agreements with certain named EGUs are not an acceptable method for implementing the emissions control strategies the MoDNR identified, because these agreements are not in effect, the trigger by which they could come into effect is not appropriate and inconsistent with the timing requirements of the good neighbor provision, and their terms allow for modification or withdrawal of requirements through processes that conflict with several bedrock CAA requirements regarding SIP revisions. Second, the MoDNR's approach of regulating only certain named existing EGU sources, rather than regulating both existing and new sources on industry-wide bases, fails to analyze or address the potential for production and emissions shifting among sources, which the EPA has consistently identified is an important consideration in developing emissions control strategies to address transport obligations. See, e.g., 70 FR 25261 (May 12, 2005).

Taken together, the deficiencies identified in this summary and further detailed in section III. lead the EPA to propose to conclude it cannot approve the MoDNR's November 2022 Submission as meeting the requirements of the good neighbor provision for the 2015 ozone NAAQS. The EPA is ready to work with the MoDNR and the State of Missouri and any other state to develop an approvable SIP submission to meet these requirements.

For decades, when evaluating SIPs and formulating FIPs, the EPA has consistently utilized the 4-step interstate transport framework (or 4-step framework), which was developed to give meaning to the critical statutory terms in CAA section 110(a)(2)(D)(i)(I) and to provide a reasonable organization to the analysis of the complex air quality challenge of interstate ozone transport. The EPA has addressed the interstate transport requirements of CAA section 110(a)(2)(D)(i)(I) with respect to prior NAAQS using the 4-step framework in several regulatory actions, including the CSAPR, which addressed interstate transport with respect to the 1997 ozone NAAQS as well as the 1997 and 2006 fine particulate matter standards, 5 and the CSAPR Update  6 and the Revised CSAPR Update, 7 both of which addressed the 2008 ozone NAAQS. 8 The EPA is using the 4-step framework to organize its evaluation of the MoDNR Air Pollution Control Program November 1, 2022, interstate transport SIP submission for the 2015 ozone NAAQS.

Shaped through the years by input from State air agencies  9 and other stakeholders on the EPA's prior interstate transport rulemakings and SIP actions, 10 as well as a number of court decisions, the EPA has developed and used the 4-step interstate transport framework to evaluate a State's obligations to eliminate interstate transport emissions under the interstate transport provision for the ozone NAAQS: (1) identify monitoring sites that are projected to have problems attaining and/or maintaining the NAAQS ( i.e., nonattainment and/or maintenance receptors); (2) identify States that impact those air quality problems in other ( i.e., downwind) States sufficiently such that the States are considered “linked” and therefore warrant further review and analysis; (3) identify the emissions reductions necessary (if any), applying a multifactor analysis, to eliminate each linked upwind State's significant contribution to nonattainment or interference with maintenance of the NAAQS at the locations identified in Step 1; and (4) adopt permanent and enforceable measures needed to achieve those emissions reductions. The EPA does not require States to use the 4-step framework in good neighbor SIP submissions, but it is a useful organizational tool that has been upheld by the Supreme Court as “permissible, workable, and equitable.” EPA v. EME Homer City Generation, L.P., 572 U.S. 489, 524 (2014).

In general, the EPA has performed nationwide air quality modeling to project ozone design values (DV), which are used in combination with measured data to identify nonattainment and maintenance receptors at Step 1. To quantify the contribution of emissions from individual upwind States on 2023 ozone design values for the identified downwind nonattainment and maintenance receptors at Step 2, the EPA has performed multiple iterations of nationwide, State-level ozone source apportionment modeling for 2023. The source apportionment modeling projected contributions to ozone at receptors from precursor emissions of anthropogenic NO X and volatile organic compounds (VOCs) in individual upwind States.

The EPA has released several documents containing projected ozone design values, contributions, and information relevant to air agencies for evaluation of interstate transport with respect to the 2015 ozone NAAQS. First, on January 6, 2017, the EPA published a notice of data availability (NODA) in which the Agency requested comment on preliminary interstate ozone transport data including projected ozone design values and interstate contributions for 2023 using a 2011 base year platform. 11 In the NODA, the EPA used the year 2023 as the analytic year for this preliminary modeling because this year aligns with the expected attainment year for Moderate ozone nonattainment areas for the 2015 ozone NAAQS. 12 On October 27, 2017, the EPA released a memorandum (October 2017 memorandum) containing updated modeling data for 2023, which incorporated changes made in response to comments (RTC) on the NODA, and was intended to provide information to assist States' efforts to develop SIP submissions to address interstate transport obligations for the 2008 ozone NAAQS. 13 On March 27, 2018, the EPA issued a memorandum (March 2018 memorandum) noting that the same 2023 modeling data released in the October 2017 memorandum could also be useful for identifying potential downwind air quality problems with respect to the 2015 ozone NAAQS at Step 1 of the 4-step interstate transport framework. 14 The March 2018 memorandum also included the then newly available contribution modeling data for 2023 to assist States in evaluating their impact on potential downwind air quality problems for the 2015 ozone NAAQS under Step 2 of the 4-step interstate transport framework. 15 The EPA notes that the MoDNR relied upon 2023 modeling contribution data released with the March 2018 memorandum in developing its 2019 SIP submission. The EPA subsequently issued two more memoranda in August and October 2018, providing additional information to States developing interstate transport SIP submissions for the 2015 ozone NAAQS concerning, respectively, potential contribution thresholds that may be appropriate to apply in Step 2 of the 4-step interstate transport framework, and considerations for identifying downwind areas that may have problems maintaining the standard at Step 1 of the 4-step interstate transport framework. 16

Following the release of the modeling data shared in the March 2018 memorandum, the EPA performed updated modeling using a 2016-based emissions modeling platform ( i.e., 2016v1). This emissions platform was developed under the EPA/Multi-Jurisdictional Organization (MJO)/State collaborative project. 17 This collaborative project was a multi-year joint effort by the EPA, MJOs, and States to develop a new, more recent emissions platform for use by the EPA and States in regulatory modeling as an improvement over the dated 2011-based platform that the EPA had used to project ozone design values and contribution data provided in the 2017 and 2018 memoranda. The EPA used the 2016v1 emissions to project ozone design values and contributions for 2023. On October 30, 2020, in the notice of proposed rulemaking for the Revised CSAPR Update, the EPA released and accepted public comment on 2023 modeling that used the 2016v1 emissions platform. 18 Although the Revised CSAPR Update addressed transport for the 2008 ozone NAAQS, the projected design values and contributions from the 2016v1 platform were also useful for identifying downwind ozone problems and linkages with respect to the 2015 ozone NAAQS. 19

Following the final Revised CSAPR Update, the EPA made further updates to the 2016-based emissions platform to include updated onroad mobile emissions from Version 3 of the EPA's Motor Vehicle Emission Simulator (MOVES3) model  20 and updated emissions projections for EGUs that reflected the emissions reductions from the Revised CSAPR Update, recent information on plant closures, and other inventory improvements. The EPA published these emissions inventories on its website in September of 2021 and invited initial feedback from States and other interested stakeholders. 21 The construct of the updated emissions platform, 2016v2, is described in the “Technical Support Document (TSD): Preparation of Emissions Inventories for the 2016v2 North American Emissions Modeling Platform,” hereafter known as the 2016v2 Emissions Modeling TSD, and is included in Docket ID No. EPA-HQ-OAR-2021-0663. The EPA performed air quality modeling using the 2016v2 emissions to provide projections of ozone design values and contributions in 2023 and 2026 that reflect the effects on air quality of the 2016v2 emissions platform. The EPA used the results of the 2016v2 modeling as part of our previous proposed evaluation of the MoDNR's interstate transport SIP submission for the 2015 ozone NAAQS, submitted on June 10, 2019, with respect to Steps 1 and 2 of the 4-step interstate transport framework. See 87 FR 9533 (February 22, 2022).

The EPA invited and received comments on the 2016v2 emissions inventories and modeling used to support proposals, including the proposal on Missouri, related to interstate transport under the 2015 ozone NAAQS. In response to these comments, the EPA made a number of updates to the 2016v2 inventories and model design to construct a 2016v3 emissions platform that was used to update the air quality modeling. The EPA used this updated modeling to inform a final rulemaking taking final action on 21 interstate transport SIP submissions for the 2015 ozone NAAQS, which included the MoDNR's June 2019 Submission, as well as a Federal implementation plan action covering 23 States, including Missouri. 22 Details on the 2016v3 air quality modeling and the methods for projecting design values and determining contributions in 2023 and 2026 are described in the TSD titled “Air Quality Modeling (AQM) Final Rule TSD—2015 Ozone NAAQS Good Neighbor Plan,” hereafter known as the Final Good Neighbor Plan AQM TSD. 23 Additional details related to the updated 2016v3 emissions platform are located in the TSD titled “Preparation of Emissions Inventories for the 2016v3 North American Emissions Modeling Platform,” hereafter known as the 2016v3 Emissions Modeling TSD, included in Docket ID No. EPA-HQ-OAR-2021-0668. 24

In this proposed action, the EPA primarily relies on modeling based on the updated 2016v3 emissions platform in evaluating the MoDNR's November 2022 Submission with respect to Steps 1 and 2 of the 4-step interstate transport framework, which will generally be referenced within this action as the “2016v3 modeling” for 2023 and 2026. As discussed further in section I.D.2. of this document, the EPA is also applying its findings regarding violating-monitor maintenance-only receptors in 2023 using certified monitoring data and regulatory design values for 2021 and 2022. The EPA used the 2016v3 modeling to calculate contributions to these receptors.

Nonetheless, we note that the basis for the EPA's disapproval of the November 2022 Submission is not affected by the choice of modeling between the 2016v3 modeling or the 2016v2 modeling on which the MoDNR based its Submission. Both sets of modeling demonstrated linkages between Missouri and multiple receptors above both a 1 percent of the NAAQS and a 1 ppb contribution threshold. The EPA does not propose to disapprove the MoDNR's Submission due to its choice of modeling, but for failing to adequately analyze and prohibit those emissions that constitute “significant contribution” to nonattainment or maintenance receptors in other States.

By this action, the EPA is not reopening the determinations made for Missouri in the Good Neighbor Plan regarding the definition of good neighbor obligations through the EPA's exercise of statutory responsibility under CAA section 110(c). Rather, this action is taken pursuant to the EPA's statutory responsibility to act on SIP submissions pursuant to CAA section 110(k). Any comments that are not relevant to the EPA's proposed basis for the disapproval of Missouri's November 2022 Submission will be treated as beyond the scope of this action.

The EPA proposes to apply a consistent set of policy judgments across all States for purposes of evaluating interstate transport obligations and the approvability of interstate transport SIP submissions for the 2015 ozone NAAQS under CAA section 110(a)(2)(D)(i)(I). These policy judgments conform with relevant case law and past agency practice as reflected in the CSAPR and related rulemakings. Employing a nationally consistent approach is particularly important in the context of interstate ozone transport, which is a regional-scale pollution problem involving many smaller contributors. Effective policy solutions to the problem of interstate ozone transport going back to the NO X SIP Call have necessitated the application of a uniform framework of policy judgments to ensure an “efficient and equitable” approach. See EME Homer City Generation, LP v. EPA, 572 U.S. 489, 519 (2014). The EPA evaluates any State's arguments for the use of alternative approaches or alternative sets of data with an eye to ensuring national consistency and avoiding inconsistent or inequitable results among upwind States and between upwind and downwind States.

The remainder of this section describes the EPA's analytic framework with respect to analytic year, definition of nonattainment and maintenance receptors, selection of contribution threshold, and multifactor control strategy assessment.

In this section, the EPA describes its process for selecting analytic years for air quality modeling and analyses performed to identify nonattainment and maintenance receptors and identify upwind State linkages. The EPA is retaining the 2023 and 2026 analytical years used to inform the obligations of the 23 States included in the Good Neighbor Plan, to ensure consistency and equitable treatment of all States. In the Good Neighbor Plan, the EPA evaluated air quality to identify receptors at Step 1 and evaluate interstate contributions at Step 2 for two analytic years: 2023 and 2026. These years are the last full ozone seasons  25 before the Moderate and Serious area attainment dates for the 2015 ozone NAAQS, which are August 3, 2024, and August 3, 2027. 26 To demonstrate attainment by these deadlines, downwind States would be required to rely on design values calculated using ozone data from 2021 through 2023 and 2024 through 2026, respectively. Areas that do not attain by the deadline may be “bumped up” to a higher nonattainment classification level per CAA sections 181 and 182, thereby incurring additional ongoing obligations. Thus, in the Good Neighbor Plan, consistent with each of its prior good neighbor rulemakings, the EPA focused its analysis in the years with the last full ozone seasons before the attainment dates ( i.e., 2023 and 2026).

Here, the MoDNR used the 2023 and 2026 analytic years in its Submission, and both the modeling it considered (2016v2) and the additional modeling the EPA took into account (2016v3) used those analytic years. Because both sets of modeling show that Missouri remains linked, the basis for the EPA's action in this case is not in relation to the acceptability of the air quality modeling or analysis the MoDNR used at Steps 1 and 2, but rather in relation to our findings that the State's approach to defining “significant contribution” is inadequate. Further, use of the 2023 and 2026 analytic years ensures consistency in the treatment of States. Where the need for parity among States or other jurisdictions in like circumstances warrants it, courts have recognized that it may be appropriate for agencies like the EPA to rely on prior datasets to ensure consistency in treatment. See Bd. County Commissioners of Weld County v. EPA, 72 F.4th 284, 290 (D.C. Cir. 2023) (upholding as reasonable the EPA's determination that “greater parity among counties and faster turnaround [ ] make the original data a better choice than partial updating”). The importance of the use of a single, already-developed dataset focused on the years 2023 and 2026 to define good neighbor obligations for all States to ensure consistency among States and for “faster turnaround” to complete this rulemaking is, in the EPA's judgment, sufficiently compelling to justify this approach here.

In Step 1, the EPA identifies monitoring sites that are projected to have problems attaining and/or maintaining the NAAQS in the 2023 analytic year. This approach reflects the EPA's interpretation of the terms “nonattainment” and “maintenance” as used in the good neighbor provision in the context of the ozone NAAQS. See 88 FR 9341-42 (February 13, 2023). Where the EPA's analysis shows that a site does not meet the definition of a nonattainment or maintenance receptor, the EPA excludes that site from further analysis under the EPA's 4-step interstate transport framework. At Step 2 of the 4-step interstate transport framework, the EPA considers those sites identified as a nonattainment or maintenance receptor in 2023 and identifies which upwind States contribute to those receptors above the contribution threshold.

This approach gives independent consideration to both the “contribute significantly to nonattainment” and the “interfere with maintenance” prongs of CAA section 110(a)(2)(D)(i)(I), consistent with the D.C. Circuit's direction in North Carolina. 27 To summarize this methodology:

The EPA identifies nonattainment receptors as those monitoring sites that are projected to have average design values that exceed the NAAQS and that are also measuring nonattainment based on the most recent monitored design values. This approach is consistent with prior transport rulemakings, such as the CSAPR Update, where the EPA defined nonattainment receptors as those areas that both currently measure nonattainment and that the EPA projects will be in nonattainment in the analytic year ( i.e., 2023). 28

In addition, the EPA identified a receptor to be a “maintenance” receptor for purposes of defining interference with maintenance, consistent with the method used in the CSAPR and upheld by the D.C. Circuit in EME Homer City Generation, L.P. v. EPA, 795 F.3d 118, 136 (D.C. Cir. 2015) ( EME Homer City II ). 29 Specifically, the EPA identified maintenance receptors as those receptors that would have difficulty maintaining the relevant NAAQS in a scenario that takes into account historical variability in air quality at that receptor. The variability in air quality was determined by evaluating the “maximum” future design value at each receptor based on a projection of the maximum measured design value over the relevant period. The EPA interprets the projected maximum future design value to be a potential future air quality outcome consistent with the meteorology that yielded maximum measured concentrations in the ambient data set analyzed for that receptor ( i.e., ozone conducive meteorology). The EPA also recognizes that previously experienced meteorological conditions ( e.g., dominant wind direction, temperatures, and air mass patterns) promoting ozone formation that led to maximum concentrations in the measured data may reoccur in the future. The maximum design value gives a reasonable projection of future air quality at the receptor under a scenario in which such conditions do, in fact, reoccur. The projected maximum design value is used to identify upwind emissions that, under those circumstances, could interfere with the downwind area's ability to maintain the NAAQS.

Nonattainment receptors are also, by definition, maintenance receptors, and so the EPA often uses the term “maintenance-only” to refer to those receptors that are not nonattainment receptors. Consistent with the concepts for maintenance receptors, as described earlier, the EPA identifies “maintenance-only” receptors as those monitoring sites that have projected average design values above the level of the applicable NAAQS, but that are not currently measuring nonattainment based on the most recent official design values. 30 In addition, those monitoring sites with projected average design values below the NAAQS, but with projected maximum design values above the NAAQS are also identified as “maintenance-only” receptors, even if they are currently measuring nonattainment based on the most recent official design values.

The Agency has looked closely at measured ozone levels at ambient monitoring sites in 2021 and 2022 for the purposes of informing the identification of potential additional receptors in 2023. As explained in more detail in the February 13, 2022, final action disapproving 19 States' good neighbor SIP submissions, and partially approving and partially disapproving two States' good neighbor SIP submissions (Disapproval Action), see 88 FR 9349-50, the EPA finds there is a basis to consider certain sites with elevated ozone levels that are not otherwise identified as receptors to be an additional type of maintenance-only receptor given the likelihood that ozone levels above the NAAQS could persist at those locations through at least 2023. These are referred to as violating-monitor maintenance-only receptors (violating-monitor receptors). In this action, the EPA proposes to use certified ambient monitoring data as an additional method to identify maintenance-only receptors. More specifically, violating-monitor receptors are monitoring sites with measured 2021 and 2022 design values and 2021 and 2022 fourth-highest (4th high) maximum daily average 8-hour (MDA8) ozone concentrations that exceed the NAAQS, despite having model-projected average and maximum design values for 2023 below the NAAQS. 31 The EPA finds these sites are at continuing risk of failing to maintain the 2015 ozone NAAQS, which justifies categorizing these sites as maintenance-only receptors. By applying the criteria that certified 2021 and 2022 design values and 2021 and 2022 4th high MDA8 ozone concentrations must all exceed the NAAQS the EPA gives due consideration to both measured air quality data and its modeling projections. This reasonably identifies monitoring sites as receptors in 2023 using this methodology. If sites do not meet these criteria, then the EPA could reasonably anticipate these sites to not have a problem maintaining the 2015 ozone NAAQS in 2023 and should therefore not be considered receptors.

In Step 2, the EPA quantifies the contribution of each upwind State to each receptor in the 2023 analytic year. The contribution metric used in Step 2 is defined as the average impact from each State to each receptor on the days with the highest ozone concentrations at the receptor based on the 2023 modeling. If a State's contribution value does not equal or exceed the threshold of 1 percent of the NAAQS ( i.e., 0.70 parts per billion (ppb) for the 2015 ozone NAAQS), the upwind State is not “linked” to a downwind air quality problem, and the EPA therefore concludes that the State does not contribute significantly to nonattainment or interfere with maintenance of the NAAQS in the downwind States. However, if a State's contribution equals or exceeds the 1 percent threshold, the State's emissions are further evaluated in Step 3, considering both air quality and cost as part of a multi-factor analysis, to determine what, if any, emissions might be deemed “significant” and, thus, must be eliminated pursuant to the requirements of CAA section 110(a)(2)(D)(i)(I).

In this proposed action, the EPA relies in the first instance on the 1 percent threshold for the purpose of evaluating a State's contribution to nonattainment or maintenance of the 2015 ozone NAAQS ( i.e., 0.70 ppb) at downwind receptors. This is consistent with the Step 2 approach that the EPA applied in the Disapproval Action and in the Good Neighbor Plan. The EPA has acknowledged that States may be able to justify use of a different threshold at Step 2. For reasons explained in section III.A. of this document, the MoDNR did not successfully make this demonstration. In addition, the EPA explained in both the proposed and final Disapproval Action and Good Neighbor Plan that the need for consistent treatment of all States counsels against recognizing alternative thresholds on a state-by-state basis absent an adequate circumstance-specific justification. See 88 FR 9373-75. Likewise, maintaining continuity across ozone NAAQS through consistent application of a 1 percent of NAAQS threshold at Step 2 is appropriate, so that, as the NAAQS is revised and made more protective, the contribution threshold is correspondingly adjusted as well. See 88 FR 36712-17; 88 FR 9371-75. See also 86 FR 23085 (use of 1 percent threshold in the Revised CSAPR Update); 81 FR 74518 (basis for use of 1 percent threshold for the 2008 ozone NAAQS in the CSAPR Update); 76 FR 48237-38 (original determination to use 1 percent threshold for the 1997 ozone NAAQS in the CSAPR).

Therefore, application of a consistent contribution threshold is necessary to identify those upwind States that should have responsibility for addressing their contribution to the downwind nonattainment and maintenance problems to which they collectively contribute. Continuing to use 1 percent of the NAAQS as the screening metric to evaluate collective contribution from many upwind States also allows the EPA (and States) to apply a consistent framework to evaluate interstate emissions transport under the interstate transport provision from one NAAQS to the next and helps ensure that good neighbor obligations align with the stringency of the NAAQS.

The EPA addresses the MoDNR's arguments for the use of higher Step 2 thresholds in section III.A.; however, to the extent those arguments are identical to those considered and rejected in disapproving Missouri's previous SIP submission, the Agency is not reopening such determinations.

Consistent with the EPA's longstanding approach to eliminating significant contribution and interference with maintenance, at Step 3, a multifactor assessment of potential emissions controls is conducted for States linked at Steps 1 and 2. The EPA's analysis at Step 3 in prior Federal actions addressing interstate transport requirements has primarily focused on an evaluation of cost-effectiveness of potential emissions controls (on a marginal cost-per-ton basis), the total emissions reductions that may be achieved by requiring such controls (if applied across all linked upwind States), and an evaluation of the air quality impacts such emissions reductions would have on the downwind receptors to which a State is linked; other factors may potentially be relevant if adequately supported. In general, where the EPA's or State-provided alternative air quality and contribution modeling establishes that a State is linked at Steps 1 and 2, it will be insufficient at Step 3 for a State merely to point to its existing rules requiring control measures as a basis for the EPA's approval of the SIP submission. The reason is that the emissions-reducing effects of all existing emissions control requirements are generally already reflected in the future year projected air quality results of the modeling for Steps 1 and 2. If the State is shown to still be linked to one or more downwind receptor(s) despite these existing controls, but that State believes it has no outstanding good neighbor obligations, the EPA expects the State to provide sufficient justification to support a conclusion that the State has adequate provisions prohibiting “any source or other type of emissions activity within the State from emitting any air pollutant in amounts which will” “contribute significantly to nonattainment in, or interfere with maintenance by,” any other State with respect to the NAAQS. CAA section 110(a)(2)(D)(i)(I). While the EPA has not prescribed a particular method for this assessment, the EPA expects States at a minimum to present a sufficient technical evaluation. This would typically include information on emissions sources, applicable control technologies, emissions reductions, costs, cost effectiveness, and downwind air quality impacts of the estimated reductions, before concluding that no additional emissions controls should be required. 32

At Step 4, States (or the EPA) develop permanent and federally enforceable control strategies to achieve the emissions reductions determined to be necessary at Step 3 to eliminate significant contribution to nonattainment or interference with maintenance of the NAAQS. For a State linked at Steps 1 and 2 to rely on an emissions control measure at Step 4 to address its interstate transport obligations, that measure must be included in the State's SIP so that it is permanent and federally enforceable. See CAA section 110(a)(2)(D) (“Each such [SIP] shall . . . contain adequate provisions . . . .”). See also CAA section 110(a)(2)(A); Committee for a Better Arvin v. EPA, 786 F.3d 1169, 1175-76 (9th Cir. 2015) (holding that measures relied on by a State to meet CAA requirements must be included in the SIP).

On June 10, 2019, the MoDNR Air Pollution Control Program made a SIP submission to address interstate transport of air pollution for the 2015 ozone NAAQS (June 2019 Submission). On February 22, 2022, the EPA proposed to disapprove the June 2019 Submission. 87 FR 9533. On January 31, 2023, the EPA signed a final rulemaking, finalizing disapproval of 19 SIP submissions, and partial approval and partial disapproval of two SIP submissions, for inadequately addressing the good neighbor provision for the 2015 ozone NAAQS including Missouri. 88 FR 9336 (Feb. 13, 2023) (February 2023 Disapproval Action). The June 2019 Submission is not at issue in this proposed action, and the EPA is not reopening its disapproval of it. 33

On November 1, 2022, the MoDNR submitted another SIP submission to the EPA addressing the infrastructure requirements of CAA section 110(a)(2), specifically the CAA section 110(a)(2)(D)(i)(I) interstate transport requirements, for the 2015 ozone NAAQS (November 2022 Submission). The November 2022 Submission is the subject of this proposed action. The November 2022 Submission was deemed complete by operation of law on May 1, 2023.

The November 2022 Submission contains the MoDNR's analysis of the State's impact on air quality in downwind States organized around the EPA's 4-step framework and based on the EPA's 2016v2 modeling at Steps 1 and 2. 34 Missouri asserts its current SIP is already addressing all of Missouri's good neighbor obligations under the 2015 ozone NAAQS. 35 The MoDNR then includes a Step 3 analysis and some potential ozone season emissions reductions at Step 4, which the MoDNR's submission provides will become effective only if the EPA approves the November 2022 Submission. 36

The MoDNR's November 2022 Submission provides background information on the EPA's 4-step interstate transport framework, the EPA's guidance for good neighbor SIPs for the 2015 ozone standard, the MoDNR's June 2019 Submission, the EPA's proposed disapproval of that Submission and the FIP that was proposed on April 6, 2022, and the MoDNR's decision to submit a new SIP submission addressing transport obligations for the 2015 ozone standard. 37

In the next portion of the November 2022 Submission, the MoDNR uses the EPA's 2016v2 modeling results to identify downwind nonattainment and maintenance receptors that may be impacted by emissions from sources in the State at Steps 1 and 2 of the 4-step interstate transport framework. In the 2016v2 modeling, Missouri contributes above 1 percent of the NAAQS to 4 receptors, including above 1 ppb to two of those receptors, see table 2.

Missouri compares its contributions in the EPA modeling released with the March 2018 memorandum with the EPA's 2016v2 modeling results for 2023 released in February 2022. In the EPA modeling released with the March 2018 memorandum, Missouri was linked to six nonattainment and maintenance receptors above one percent of the level of the 2015 ozone NAAQS (0.70 ppb). See table 1. In the 2016v2 modeling Missouri is not linked to those six receptors in 2023 but is identified as linked to four other receptors. See table 2. For the monitor (Site ID: 260050003) in Allegan, MI; the monitor (Site ID: 261630019) in Wayne, MI; the monitor (Site ID: 482011039) in Harris, TX; and the monitor (Site ID: 550790085) in Milwaukee, WI; the 2016v2 modeling indicates that these monitors' 2023 design values would not be above the NAAQS and therefore they were not identified as receptors at Step 1. The 2016v2 modeling indicates that Missouri's contribution to the receptor ID 480391004, Brazoria, TX, is below the 1 percent of the NAAQS threshold and so Missouri is not linked to it at Step 2. For the receptor (Site ID: 551170006) in Sheboygan, WI, the MoDNR notes that in the EPA's updated 2016v2 modeling, this monitor is still projected to be a nonattainment receptor, but the EPA did not calculate any upwind State contributions to it because there were fewer than five days where the model-predicted MDA8 was above 60 ppb. 38 Missouri is therefore not identified as being linked to this receptor in the 2016v2 modeling.

Why we need to publish a rule. Under the Act (16 U.S.C. 1531 et seq. ), the term “species” includes any subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature. A subspecies warrants listing under the Act if it meets the definition of an endangered species (in danger of extinction throughout all or a significant portion of its range) or a threatened species (likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range). If we determine that a subspecies warrants listing, we must list the subspecies promptly and designate the subspecies' critical habitat to the maximum extent prudent and determinable. We have determined that the eastern regal fritillary (eastern subspecies) meets the Act's definition of an endangered species and that the western regal fritillary (western subspecies) meets the Act's definition of a threatened species; therefore, we are proposing to list them as such. Listing a subspecies as an endangered or threatened species can be completed only by issuing a rule through the Administrative Procedure Act rulemaking process (5 U.S.C. 551 et seq. ).

What this document does. We propose to list the eastern regal fritillary as an endangered species and to list the western regal fritillary as a threatened species with a 4(d) rule. As explained later in this document, we conclude that the designation of critical habitat for these subspecies is not determinable at this time.

The basis for our action. Under the Act, we may determine that a subspecies is an endangered or threatened species because of any of five factors: (A) the present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence. We have determined that the eastern regal fritillary is endangered due to the loss and fragmentation of its remaining grassland habitats from invasive plants and woody encroachment (Factor A) and periodic disturbances, such as fire, military operations, and other management activities if they are too large, frequent, or intense (Factor A). These threats are exacerbated by the ongoing effects of drought and climate change (Factors A and E).

We have determined that the western regal fritillary is threatened due to the expected continued loss and fragmentation of large, intact native grasslands through conversion by agriculture and development (Factor A); invasive plants and woody vegetation (Factor A); the reduction of violets and nectar sources from the broadcast application of herbicides (Factor A); and periodic disturbances from fire, mowing, and haying that are too large, frequent, or intense (Factor A). These threats are all exacerbated by the ongoing and expected effects of drought and climate change (Factors A and E).

Section 4(a)(3) of the Act requires the Secretary of the Interior (Secretary), to the maximum extent prudent and determinable, to designate critical habitat concurrent with listing. Section 3(5)(A) of the Act defines critical habitat as (i) the specific areas within the geographical area occupied by the species at the time it is listed, on which are found those physical or biological features (I) essential to the conservation of the species and (II) which may require special management considerations or protection; and (ii) specific areas outside the geographical area occupied by the species at the time it is listed, upon a determination by the Secretary that such areas are essential for the conservation of the species. Section 4(b)(2) of the Act states that the Secretary must make the designation on the basis of the best scientific data available and after taking into consideration the economic impact, the impact on national security, and any other relevant impacts of specifying any particular area as critical habitat.

We intend that any final action resulting from this proposed rule will be based on the best scientific and commercial data available and be as accurate and as effective as possible. Therefore, we request comments or information from governmental agencies, Native American Tribes, the scientific community, industry, or any other interested parties concerning this proposed rule. We particularly seek comments concerning:

(1) The subspecies' biology, range, and population trends, including:

(a) Current ranges, including distribution patterns and the locations of any additional populations of the subspecies;

(b) Current population levels, and current and projected trends; and

(c) Past and ongoing conservation measures for the subspecies, their habitats, or both.

(2) Threats and conservation actions affecting the subspecies, including:

(a) Factors that may be affecting the continued existence of the subspecies, which may include habitat modification or destruction, overutilization, disease, predation, the inadequacy of existing regulatory mechanisms, or other natural or manmade factors;

(b) Relevant data concerning any threats (or lack thereof) to the subspecies; and

(c) Existing regulations or conservation actions that may be addressing threats to these subspecies.

(3) Additional information concerning the current status of the subspecies.

(4) Information to assist with applying or issuing protective regulations under section 4(d) of the Act that may be necessary and advisable to provide for the conservation of the western regal fritillary.

(a) In particular, information concerning the extent to which we should include any of the section 9 prohibitions in the 4(d) rule; or

(b) whether we should consider any additional or different exceptions from the prohibitions in the 4(d) rule.

Please include sufficient information with your submission (such as scientific journal articles or other publications) to allow us to verify any scientific or commercial information you include.

Please note that submissions merely stating support for, or opposition to, the action under consideration without providing supporting information, although noted, do not provide substantial information necessary to support a determination. Section 4(b)(1)(A) of the Act directs that determinations as to whether any species is an endangered or a threatened species must be made solely on the basis of the best scientific and commercial data available.

You may submit your comments and materials concerning this proposed rule by one of the methods listed in ADDRESSES . We request that you send comments only by the methods described in ADDRESSES .

If you submit information via https://www.regulations.gov, your entire submission—including any personal identifying information—will be posted on the website. If your submission is made via a hardcopy that includes personal identifying information, you may request at the top of your document that we withhold this information from public review. However, we cannot guarantee that we will be able to do so. We will post all hardcopy submissions on https://www.regulations.gov.

Comments and materials we receive, as well as supporting documentation we used in preparing this proposed rule, will be available for public inspection on https://www.regulations.gov.

Our final determinations may differ from this proposal because we will consider all comments we receive during the comment period as well as any relevant information that becomes available after this proposal is published. Based on the new information we receive (and, if relevant, any comments on that new information), we may conclude that the eastern subspecies is threatened instead of endangered or that the western subspecies is endangered instead of threatened, or we may conclude that one or both of the subspecies do not warrant listing as either an endangered species or a threatened species. In addition, we may change the parameters of the prohibitions or the exceptions to those prohibitions in the protective regulations under section 4(d) for the western regal fritillary if appropriate in light of comments and new information received. For example, we may expand the prohibitions to include prohibiting additional activities if we conclude that those additional activities are not compatible with conservation of the western regal fritillary. Conversely, we may establish additional exceptions to the prohibitions in the final rule if we conclude that the activities would facilitate or are compatible with the conservation and recovery of the western subspecies. In our final rule, we will clearly explain our rationale and the basis for our final decisions, including why we made changes, if any, that differ from this proposal.

Section 4(b)(5) of the Act provides for a public hearing on this proposal, if requested. Requests must be received by the date specified in DATES . Such requests must be sent to the address shown in FOR FURTHER INFORMATION CONTACT . We will schedule a public hearing on this proposal, if requested, and announce the date, time, and place of the hearing, as well as how to obtain reasonable accommodations, in the Federal Register and local newspapers at least 15 days before the hearing. We may hold the public hearing in person or virtually via webinar. We will announce any public hearing on our website, in addition to the Federal Register . The use of virtual public hearings is consistent with our regulations at 50 CFR 424.16(c)(3).

We designated the regal fritillary as a Category 2 candidate in the May 22, 1984, Review of Invertebrate Wildlife for Listing as Endangered or Threatened Species (49 FR 21664). We defined Category 2 candidates as taxa for which we had information that proposed listing was possibly appropriate, but conclusive data on biological vulnerability and threats were not available to support a proposed rule at the time. The species remained so designated in subsequent annual candidate notices of review (CNORs) (54 FR 554, January 6, 1989; 56 FR 58804, November 21, 1991; 59 FR 58982, November 15, 1994). In the February 28, 1996, CNOR (61 FR 7596), we discontinued the designation of Category 2 species as candidates; therefore, the regal fritillary was no longer a candidate species.

On April 19, 2013, we received a petition from WildEarth Guardians to list the regal fritillary under the Act. On September 18, 2015, we published in the Federal Register (80 FR 56423) a substantial 90-day finding for the regal fritillary. The eastern and western subspecies are the only two subspecies of the regal fritillary species, so this document constitutes our 12-month warranted petition finding and our proposed listing rule for the regal fritillary.

A species status assessment (SSA) team prepared an SSA report for the eastern and western subspecies of regal fritillary. The SSA team was composed of Service biologists, in consultation with other species experts. The SSA report represents a compilation of the best scientific and commercial data available concerning the status of both subspecies, including the impacts of past, present, and future factors (both negative and beneficial) affecting the subspecies.

In accordance with our joint policy on peer review published in the Federal Register on July 1, 1994 (59 FR 34270), and our August 22, 2016, memorandum updating and clarifying the role of peer review in listing actions under the Act, we solicited independent scientific review of the information contained in the SSA report for the eastern and western subspecies. We sent the SSA report to 14 appropriate and independent peer reviewers and received 5 responses. Results of this structured peer review process can be found at https://www.regulations.gov under Docket No. FWS-R6-ES-2023-0182 and at https://fws.gov/library/categories/peer-review-plans. In preparing this proposed rule, we incorporated the results of these reviews, as appropriate, into the SSA report, which is the foundation for this proposed rule.

As discussed in Peer Review above, we received comments from five peer reviewers on the draft SSA report. We reviewed all comments from the peer reviewers for substantive issues and new information regarding the contents of the SSA report. The peer reviewers concurred with our methods and conclusions, and provided additional information, clarifications, and suggestions, including corrections on wingspan measurements, suggestions for additional relationships between nodes on our conceptual models, potential uncertainty associated with geospatial landcover and climate models, and other editorial suggestions. We updated the SSA report accordingly. No substantive changes to our analysis and conclusions within the SSA report were deemed necessary, and we addressed all peer reviewer comments in version 1.0 of the SSA report (Service 2023, entire).

A thorough review of the taxonomy, life history, and ecology of the regal fritillary, including both the eastern and western subspecies, is presented in the SSA report (Service 2023, pp. 44-68, 180-194). We use the term “species” to refer to the regal fritillary and any information describing or relating to the species applies to both the eastern and western subspecies, unless specified otherwise.

The regal fritillary is a large, nonmigratory butterfly found in the grassland habitats of the Fort Indiantown Gap (FTIG) National Guard Training Center in Pennsylvania (the eastern subspecies) and portions of 14 States, from Indiana to Colorado and from North Dakota to Oklahoma (the western subspecies). Adults have dorsal orange forewings and dark hindwings that feature black bars, fine white markings, and two rows of large spots at the base of the wings. Adults are similar in size to the monarch butterfly ( Danaus plexippus ), with wingspans ranging from approximately 6.8 to 10.5 centimeters (cm) (2.67 to 4.13 inches (in)) (Selby 2007, p. 14); however, the regal fritillary's predominately orange forewings and dark hindwings distinguish it from other butterflies (Service 2023, p. 44).

The regal fritillary has one generation per year. In the late summer and early fall, females lay eggs that hatch into larvae within 2 to 3 weeks. The larvae overwinter in nearby grassland vegetation before emerging in early spring to search for violets ( Viola spp.), their only food source (Royer and Marrone 1992, p. 21; Kopper et al. 2000, pp. 661, 663). In late May through mid-July, the larvae pupate in the leaf litter of warm season grasses (Selby 2007, p. 32; Ferster and Vulinec 2010, p. 7) and emerge as adults beginning in June (Service 2023, pp. 49, 50). Adults rely on nectar sources for food, and reproductive rates improve when nectar plants are abundant and high-quality (Wagner et al. 1997, p. 268; Selby 2007, p. 33). Adult males live for approximately 4 to 6 weeks and begin to die off in mid-July; adult females live for 8 to 12 weeks and may survive into late October (Wagner et al. 1997, p. 266; Kopper et al. 2001, pp. 174-175; Service 2023, pp. 4, 49).

Regal fritillary adults are strong and rapid flyers and may move long distances in search of nectar (Schweitzer 1989, p. 135; Selby 2007, p. 26; Service 2023, p. 50). Adults, particularly females, can move significant distances, up to 161 kilometers (100 miles), during their several-months-long lifespan to access suitable habitats on the landscape (Hammond 2021, pers. comm.; Service 2023, p. 50). Individuals may disperse to avoid localized threats and poor habitat conditions, which allows the species to respond to changing environmental conditions and to recolonize suitable habitats, but dispersal depends on the availability of nectar and the connectivity and size of the available habitats (Schweitzer 1989, p. 135; Selby 2007, p. 26; Hammond 2021, pers. comm.; Service 2023, pp. 50, 192). Recolonization may fail if source populations are too far away or if habitat patches are too small, isolated, disconnected, or degraded (Hammond 2021, pers. comm.; Service 2023, p. 50).

The regal fritillary is a landscape-level species that needs large, intact grasslands at a landscape scale, and depends on a shifting mosaic of large, well-connected, diverse grasslands with violets for larvae; nectar sources for adults; and warm season, native bunchgrasses for shelter at all life stages (Ferster and Vulinec 2010, p. 39; Caven et al. 2017, p. 199; Service 2023, pp. 51, 55). The grasslands need to be large and contiguous, generally more than 3.86 square miles (1,000 hectares), and be maintained by periodic disturbances. Such disturbances, which include fire, mowing, and military operations for the eastern subspecies, and fire, haying, and grazing for the western subspecies, help maintain the grasslands by reducing woody plants and encroachment (Service 2023, pp. 4, 8, 69-85).

However, large, intense or frequent, or permanent disturbances can also cause negative individual- or population-level effects, particularly during the sedentary, early life stages of the butterfly (Service 2023, p. 4). The regal fritillary cannot survive in altered landscapes, including row crop fields, nonnative pastures, developed areas surrounding prairie remnants (Selby 2007, p. 3), or forests (Service 2023, p. 51). As a result, the regal fritillary is considered a grassland specialist (Swengel 1996, p. 76) and an indicator of the health of native prairie (Royer and Marrone 1992, p. 4; Service 2023, p. 51).

The regal fritillary is also a “boom-and-bust” species, which means that when environmental conditions and habitat characteristics are favorable, significant increases in annual population abundance and distribution may occur (Service 2023, pp. 4, 280, 284). When conditions are unfavorable, individuals become scarce, and local extirpations may occur in areas that may be recolonized when and if conditions improve. The ability to disperse over relatively long distances and the boom-and-bust dynamic helps the species withstand stochastic events, catastrophic events, and environmental change. However, the loss and fragmentation of grassland habitats can interfere with the boom-and-bust pattern by isolating populations, contributing to local extirpations, and limiting recolonizations.

The largest and most resilient regal fritillary populations occupy large, diverse, contiguous grasslands at a landscape scale. These large populations better withstand stochastic events and function as source populations for the species to recolonize nearby areas when favorable conditions return. Assemblages of regal fritillary populations create a metapopulation, which for the regal fritillary includes at least three or more populations separated by 32 to 160 kilometers (20 to 100 miles) that are linked by infrequent dispersal, are spread over multiple habitats and breeding sites, and have some local areas remaining occupied despite losses of individual populations. This metapopulation structure provides reliable habitat refugia during adverse conditions and source populations for recolonizations during favorable conditions (Schweitzer 1989, p. 135; Royer and Marrone 1992, p. 26; Service 2023, p. 55). Metapopulation-level processes, supported by the species' dispersal ability and boom-and-bust dynamic, appear to be critical to the long-term persistence of the regal fritillary. However, the fragmentation of prairie grasslands across the species' overall range, largely the result of conversion to other land uses for the western subspecies and woody encroachment for the eastern subspecies, has resulted in smaller, more widely separated populations with genetic exchange occurring at reduced rates from historical levels. As a result, the metapopulation structure is currently absent for the eastern subspecies and limited for the western subspecies, particularly in the Midwest (Schweitzer 1993, p. 9; Service 2023, p. 55).

Historically, the regal fritillary was considered common among prairie and grassland butterflies in the United States, particularly in tallgrass prairie habitats (Hammond and McCorkle 1983(84), p. 219), with an overall historical range across 32 States (Selby 2007, pp. 10, 14; Service 2023, p. 56). But, beginning in the 1930s and continuing through the 1990s, the species' overall range contracted substantially, most severely in the East and Midwest (Wagner et al. 1997, pp. 261, 262; Selby 2007, p. 17). Following this decline, the eastern subspecies now occupies a small portion of Pennsylvania at FTIG, and the western subspecies occupies portions of 14 States (Service 2023, p. 57). After 2009, when the last eastern individual was observed in Virginia (Chazal 2014, p. 2), FTIG in Pennsylvania became the sole remaining site in the East with a known population (Service 2023, p. 57). Several factors may have contributed to the rapid decline of the species in the East, including land use changes, development, forest succession, pesticide use, and other activities or events that resulted in the collapse of the metapopulation processes (Williams 1999, p. 3; Schweitzer 1993, p. 9). In the West, the loss of native prairie grasslands since the 1800s via conversion to agriculture and development had the most significant impact on the regal fritillary (Service 2023, pp. 5, 57).

Taxonomists previously classified the regal fritillary as Speyeria idalia, but now classify the species as Argynnis idalia, in the subgenus Speyeria. The eastern and western subspecies are genetically and morphologically different and are currently separated by approximately 869 kilometers (540 miles), from Pennsylvania to Indiana, so genetic exchange between the two subspecies is highly unlikely (Service 2023, pp. 34, 46). The best available scientific information indicates that there are two valid subspecies of regal fritillary: the eastern subspecies ( A. i. idalia ) and the western subspecies ( A. i. occidentalis ) (Williams 2001b, entire; Williams et al. 2003, p. 17; Keyghobadi et al. 2013, p. 235; Rutins et al. 2022, p. 4; Service 2023, pp. 182-186). We discuss the distribution and trends for each subspecies below, with additional information provided in our SSA report (Service 2023, entire).

The eastern subspecies is currently found as a single population located on FTIG. Moisture levels are more mesic (moderately moist) in the East than in the West. The eastern subspecies has distinct haplotypes that are not present in any other known extant regal fritillary population (Williams 2001, pp. 146, 151; Service 2023, pp. 34, 64). Currently, there are approximately 800 individuals in the population at FTIG, and the population exhibits signs of restricted gene flow (Keyghobadi et al. 2006, p. 3; Rutins et al. 2022, p. 4; Service 2023, pp. 64-65).

Established in 1931, FTIG has been used continuously for military training exercises that periodically disturb the ground and open grassland patches, and incidentally help maintain remnant grassland patches as an old field, successional stage (Ferster et al. 2008, p. 142). Without these activities, the remaining grassland habitats for the eastern regal fritillary would have converted to forests like the surrounding ecoregions (Ferster et al. 2008, p. 142). FTIG also uses prescribed burns and mechanical treatments, such as mowing and tree cutting, specifically to maintain and improve the eastern subspecies' remaining grassland habitats (Ferster and Vulinec 2010, pp. 39, 40; Service 2023, p. 52). As a result, the eastern subspecies is found in the remaining grasslands at FTIG on approximately 457 acres (185 hectares) that are the result of military and other activities that maintain open areas and promote regal fritillary presence (Zercher et al. 2002, p. 13; Service 2023, p. 61). FTIG has monitored the eastern subspecies since 1997 (Ferster and Vulinec 2010, p. 31) and conducts surveys annually to monitor the population and habitats (Zercher et al. 2002, pp. M-6-M-8; Pennsylvania Department of Military and Veterans Affairs (PADMVA) 2021, entire; Zografou et al. 2021, p. 10; Rutins et al. 2022, p. 2). Conservation activities to benefit the eastern subspecies at FTIG are conducted through an integrated natural resources management plan (INRMP); however, the activities at FTIG that benefit the eastern subspecies could change at any time depending on funding and priorities (PADMVA 2021, pp. 20, 31; Swartz 2022, pers. comm.).

The western subspecies currently occupies portions of 14 States: Arkansas, Colorado, Illinois, Indiana, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, Oklahoma, South Dakota, Wisconsin, and Wyoming. The western subspecies historically occupied a much larger portion of the overall species' range than the eastern subspecies. Thus, while the eastern subspecies was nearly eliminated with the east-to-west contraction in the subspecies' range, populations of the western subspecies remain where large grasslands are unconverted, intact, and contiguous. However, the western subspecies is generally considered to have a declining population trend, largely a result of land conversion to agriculture and development. Habitat fragmentation generally decreases east to west across the western subspecies' range, and as the size and number of suitable prairie remnants increases, there is a corresponding increase in size, number, and long-term viability of the western subspecies' populations (Selby 2007, p. 18).

The western subspecies occurs in 21 populations, or analytical units, as described in the SSA report (Service 2023, pp. 65-67), and 3 representation units: the Midwest, Northern Great Plains, and Central Great Plains. In the Midwest, across Arkansas, Illinois, Indiana, Iowa, Minnesota, Missouri, and Wisconsin, western regal fritillary populations are now restricted to small, isolated patches of prairie remnants that are generally less than 98.9 acres (40 hectares) in size (Robertson et al. 1997 in Panzer and Schwartz 2000, p. 363), scattered across a landscape primarily dominated by agriculture. To the west, the Northern and Central Great Plains are the remaining strongholds for the western subspecies, as large, intact grasslands remain. Western regal fritillary populations within Kansas, Nebraska, North Dakota, and South Dakota are relatively larger and more numerous, due to the less fragmented suitable grassland patches compared to those in the Midwest (Selby 2007, p. 20). Approximately 84 percent of the western regal fritillary's gross, overall range (the outer boundary of all 21 populations) is privately owned (Service 2023, p. 66). Approximately 7 percent of this gross, overall range is Tribal, 4 percent is State, 2 percent is managed by the Bureau of Land Management, 2 percent is managed by the U.S. Forest Service, and less than 1 percent each is managed by the Service, the Department of Defense, and the National Park Service (Service 2023, p. 66).

The Northern Great Plains and Central Great Plains representation units currently support relatively more intact and better-connected grasslands, primarily used for livestock grazing or haying, than the Midwest unit, but the plains units are drier, are more prone to drought, and have fewer tallgrass species comprising the grasslands, which may reduce the quality of the habitats for the western regal fritillary. The Northern Great Plains representation unit experiences shorter growing seasons and colder weather patterns than those in the Central Great Plains, which may also reduce the quality of the habitats for the western regal fritillary. Habitats in the Midwest representation unit are primarily small, isolated patches in an agriculturally dominated landscape, and many sites exist as conservation preserves, i.e., small remnants of the once-vast tallgrass prairie, which may be less than suitable for the western regal fritillary (Service 2023, p. 130).

At the western extent of the western subspecies' overall range, grasslands are drier and classified as shortgrass prairie rather than tallgrass or mixed grass, which may provide lower quality habitat for the western subspecies. As a result, populations tend to be small and isolated. Scattered occurrences in the western part of the western subspecies' overall range generally occur in riparian zones or other moist habitats where nectar sources and violets are available (Selby 2007, p. 14). The States on both the western and southern fringes of the regal fritillary's range, including Arkansas, Colorado, Oklahoma, and Wyoming, are sparsely occupied by the western subspecies, with individuals occurring only in the portions of those States that border adjacent occupied areas in other States, including Kansas and Nebraska. Western regal fritillary individuals have been observed in Montana, but there are no known populations (Service 2023, p. 56).

Section 4 of the Act (16 U.S.C. 1533) and the implementing regulations in title 50 of the Code of Federal Regulations set forth the procedures for determining whether a species is an endangered species or a threatened species, issuing protective regulations for threatened species, and designating critical habitat for endangered and threatened species. On April 5, 2024, jointly with the National Marine Fisheries Service, we issued a final rule that revised the regulations in 50 CFR part 424 regarding how we add, remove, and reclassify endangered and threatened species and what criteria we apply when designating listed species' critical habitat (89 FR 24300). On the same day, we published a final rule revising our protections for endangered species and threatened species at 50 CFR 17 (89 FR 23919). These final rules are now in effect and are incorporated into the current regulations.

The Act defines an “endangered species” as a species that is in danger of extinction throughout all or a significant portion of its range, and a “threatened species” as a species that is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range. The Act requires that we determine whether any species is an endangered species or a threatened species because of any of the following factors:

(A) The present or threatened destruction, modification, or curtailment of its habitat or range;

(B) Overutilization for commercial, recreational, scientific, or educational purposes;

(C) Disease or predation;

(D) The inadequacy of existing regulatory mechanisms; or

(E) Other natural or manmade factors affecting its continued existence.

These factors represent broad categories of natural or human-caused actions or conditions that could have an effect on a species' continued existence. In evaluating these actions and conditions, we look for those that may have a negative effect on individuals of the species, as well as other actions or conditions that may ameliorate any negative effects or may have positive effects.

We use the term “threat” to refer in general to actions or conditions that are known to or are reasonably likely to negatively affect individuals of a species. The term “threat” includes actions or conditions that have a direct impact on individuals (direct impacts), as well as those that affect individuals through alteration of their habitat or required resources (stressors). The term “threat” may encompass—either together or separately—the source of the action or condition or the action or condition itself.

However, the mere identification of any threat(s) does not necessarily mean that the species meets the statutory definition of an “endangered species” or a “threatened species.” In determining whether a species meets either definition, we must evaluate all identified threats by considering the species' expected response and the effects of the threats—in light of those actions and conditions that will ameliorate the threats—on an individual, population, and species level. We evaluate each threat and its expected effects on the species, then analyze the cumulative effect of all of the threats on the species as a whole. We also consider the cumulative effect of the threats in light of those actions and conditions that will have positive effects on the species, such as any existing regulatory mechanisms or conservation efforts. The Secretary determines whether the species meets the definition of an “endangered species” or a “threatened species” only after conducting this cumulative analysis and describing the expected effect on the species.

The Act does not define the term “foreseeable future,” which appears in the statutory definition of “threatened species.” Our implementing regulations at 50 CFR 424.11(d) set forth a framework for evaluating the foreseeable future on a case-by-case basis, which is further described in the 2009 Memorandum Opinion on the foreseeable future from the Department of the Interior, Office of the Solicitor (M-37021, January 16, 2009; “M-Opinion,” available online at https://www.doi.gov/sites/doi.opengov.ibmcloud.com/files/uploads/M-37021.pdf ). The foreseeable future extends as far into the future as the U.S. Fish and Wildlife Service and National Marine Fisheries Service (hereafter, the Services) can make reasonably reliable predictions about the threats to the species and the species' responses to those threats. We need not identify the foreseeable future in terms of a specific period of time. We will describe the foreseeable future on a case-by-case basis, using the best available data and taking into account considerations such as the species' life-history characteristics, threat projection timeframes, and environmental variability. In other words, the foreseeable future is the period of time over which we can make reasonably reliable predictions. “Reliable” does not mean “certain”; it means sufficient to provide a reasonable degree of confidence in the prediction, in light of the conservation purposes of the Act.

The SSA report documents the results of our comprehensive biological review of the best scientific and commercial data regarding the status of the species, including an assessment of the potential threats to the species. The SSA report does not represent our decision on whether the species should be proposed for listing as an endangered or threatened species under the Act. However, it does provide the scientific basis that informs our regulatory decisions, which involve the further application of standards within the Act and its implementing regulations and policies.

To assess the viability of the eastern and western subspecies of regal fritillary, we used the three conservation biology principles of resiliency, redundancy, and representation (Shaffer and Stein 2000, pp. 306-310). Briefly, resiliency is the ability of the species to withstand environmental and demographic stochasticity (for example, wet or dry, warm or cold years); redundancy is the ability of the species to withstand catastrophic events (for example, droughts, large pollution events); and representation is the ability of the species to adapt to both near-term and long-term changes in its physical and biological environment (for example, climate conditions, pathogens). In general, species viability will increase with increases in resiliency, redundancy, and representation (Smith et al. 2018, p. 306). Using these principles, we identified the subspecies' ecological requirements for survival and reproduction at the individual, population, and subspecies levels, and described the beneficial and risk factors influencing the subspecies' viability.

The SSA process can be categorized into three sequential stages. During the first stage, we evaluated the subspecies' life-history needs. The next stage involved an assessment of the historical and current conditions of the subspecies' demographics and habitat characteristics, including an explanation of how each subspecies arrived at its current condition. The final stage of the SSA involved making projections about the subspecies' responses to positive and negative environmental and anthropogenic influences. Throughout these stages, we used the best available information to characterize viability as the ability of a subspecies to sustain populations in the wild over time, which we then used to inform our regulatory decision.

The following is a summary of the key results and conclusions from the SSA report; the full SSA report can be found at Docket No. FWS-R6-ES-2023-0182 on https://www.regulations.gov.

In this discussion, we review the biological condition of the eastern and western regal fritillary and their resources, and the threats that influence each subspecies' current and future condition, in order to assess each subspecies' overall viability and the risks to that viability. We analyze these factors both individually and cumulatively to determine the current condition of each of the subspecies and project the future condition of each subspecies under several plausible future scenarios. We begin with a summary of the species' needs and risk factors, which are generally similar for both subspecies, followed by a summary of conditions first for the eastern subspecies and then the western subspecies.

Eastern and western regal fritillary individuals share many of the same needs, including large, contiguous blocks of native grasslands, violets to support larvae, warm season bunchgrasses for shelter, and nectar sources for adults (Service 2023, pp. 5-8, 69-85), so this discussion applies to both the eastern and western subspecies. In general, regal fritillary individuals need an adequate abundance of violets and nectar sources, appropriate grassland conditions (including litter, tall or shrubby cover), warm season bunchgrass tussocks, and adequate moisture and ambient temperatures in order to breed, feed, and shelter. Grasses are generally native species (indigenous to the particular area), and are either tallgrasses or mixed grasses, although the eastern regal fritillary may be more tolerant of nonnative grasses with similar bunchgrass structure. Ambient temperatures need to be suitable, generally between 75 to 105 °F (24 to 41°C) during the appropriate season for larvae to grow and for adults to survive (McCorkle and Hammond 1988, p. 192; Selby 2007, p. 36; Nail 2016, pp. 4, 9, 13, 15; Klockmann and Fischer 2017, p. 10872; Service 2023, p. 76). The grasslands need to be sufficiently large and contiguous (Kelly and Debinski 1998, p. 272; Schweitzer 1989, p. 134), ideally more than 2,471 acres (1,000 hectares) in size, and be maintained by periodic disturbances (Service 2023, pp. 8, 70-86).

The regal fritillary is a landscape-scale (spatially heterogeneous geographic areas characterized by diverse interacting patches or ecosystems) species, so large, contiguous blocks of native grasslands are the species' primary resource need (Service 2023, pp. 4, 55, 81-86). Large, contiguous grasslands tend to have more variable site conditions that support more diverse plant life; their greater area encompasses more habitat overall, and they are more likely to exhibit the shifting mosaics of heterogeneous habitats that favor sufficiently resilient regal fritillary populations. Generally, the larger the grassland patch, the better it supports abundant and adequately resilient regal fritillary populations, as long as the patch is also maintained with periodic disturbance.

Individuals do not appear to prefer small habitat patches (Schweitzer 1989, p. 134), which do not support the required shifting resources and disturbance regimes that maintain grassland habitats and sufficiently resilient regal fritillary populations. For the western subspecies, small habitat patches may be as small as 400 acres (162 hectares) in size (Hammond 2021, pers. comm; Service 2023, pp. 82-84). Small grassland tracts containing regal fritillary colonies may be more vulnerable to extirpation than larger blocks of native grasslands, but multiple colonies on small patches that are close to one another and occur as part of a collectively larger group of habitats may function together as a population. When adults in colonies can move across the matrix to reach other suitable habitat patches, the collective occupied habitats may exhibit diverse conditions that can better support the species' life-history needs.

To be sufficiently resilient, regal fritillary populations need to be of adequate size, with at least 200 to 500 adults or more to maintain genetic diversity and withstand stochastic events (Service 2023, p. 89). For redundancy and representation, the species needs metapopulation processes supported by an adequate number and distribution of sufficiently connected, large populations across the large, contiguous grasslands to withstand catastrophic events and adapt to environmental change (Service 2023, pp. 7-8, 89-91).

We reviewed the potential risk factors ( i.e., threats, stressors) that could be affecting the eastern and western subspecies of regal fritillary (Service 2023, pp. 8-11, 93-120, 215-277). Here, we discuss only those risk factors in detail that we considered drivers of resiliency, or those that could meaningfully affect the status of either subspecies. Many of the threats and risk factors are the same or similar for both subspecies, so where the effects are expected to be similar, we present one summary that applies to both subspecies. Where the threats and their effects may be unique to one subspecies, we address those specifically.

Both subspecies are vulnerable to fragmentation and isolation when habitats are degraded or lost. The primary risk factors ( i.e., threats) affecting the status of the eastern subspecies are invasive plants, particularly woody encroachment that results in forest succession; drought; climate change factors; and periodic disturbances from large or intense fire or other activities. The eastern subspecies is vulnerable to woody encroachment, and periodic disturbances are necessary to ensure the grasslands do not become reforested, but these disturbances may also present a risk if they are too frequent or intense.

The primary risk factors ( i.e., threats) affecting the status of the western subspecies are grassland conversion, primarily due to agriculture; herbicides that are applied broadly (often aerially); drought; invasive grasses and woody vegetation; periodic disturbances from fire, haying, and grazing; and climate change factors (Service 2023, pp. 10, 119-120). Although disease, predation, parasitism, competition and hybridization with sympatric butterflies, and collection may affect individuals, we did not find these risk factors to be current or future threats to either subspecies. We summarize these risk factors below, with additional detail and analysis provided in our SSA report (Service 2023, pp. 8-11, 93-120, 215-277).

This risk factor applies only to the western subspecies. An estimated 400 million acres (162 million hectares) of native prairie historically existed in North America prior to European settlement in the 1800s; these biomes have since been converted primarily to agriculture, resulting in as much as a 99.9 percent reduction in native prairie ecosystems, with the most severe declines among former tallgrass habitats (Samson and Knopf 1994, p. 418; Service 2023, p. 97). Conversion of grasslands to other uses, such as for agriculture and development, reduces the amount, availability, connectedness, size, and quality of the native grasslands needed by the regal fritillary (Hammond and McCorkle 1983(84), p. 218; Davis et al. 2007, p. 1342; Powell et al. 2007, p. 124; Selby 2007, p. 3; Sims 2017, p. 1; Swengel and Swengel 2017, p. 2; Marschalek 2020, p. 891; Niemuth et al. 2021, p. 2). While agriculture is the dominant activity that has reduced North American grasslands, any development activity that removes native prairie sod, such as road construction, road maintenance, gravel mining, housing and commercial developments, and energy projects, may reduce and fragment western regal fritillary habitat (Selby 2007, p. 3; Service 2023, pp. 98-100).

The majority of tallgrass prairie that remains today, particularly in the Midwest, is limited to small, isolated remnant tracts that are fractions of their former size and extent. Farther west, mixed-grass prairie has also been impacted by conversion and other uses; mixed-grass prairie has been reduced to 30 percent of historical amounts (World Rangeland Learning Experience 2021, entire). Much of the mixed-grass prairie is also fragmented and isolated due to grassland conversion. Shortgrass prairies at the western edge of the western subspecies' range are the most intact, but western regal fritillary populations may not occur there and may instead be found as small, ephemeral colonies in scattered moist habitats within these relatively dry grasslands (Selby 2007, p. 24).

Conversion of grasslands to agriculture reduces and fragments western regal fritillary habitats and isolates populations, which, when they are reduced to small, isolated remnant habitat patches, are vulnerable to local extirpations. Remaining grassland patches may be too small to support the violets, grasses, and nectar sources needed by individuals, and the patches are often surrounded by an unsuitable matrix of agriculture and development. Conversion to agriculture and development present a barrier to dispersal and gene flow by preventing individuals from either attempting to disperse or reducing the likelihood that dispersals will result in successful recolonization. When dispersals are less successful, recolonizations become less likely, genetic diversity declines, inbreeding may suppress population expansion, populations are less able to adapt to their changing environment, and local extirpations may begin to outpace recolonizations (Service 2023, p. 98).

Agricultural conversion of grasslands occurs at a rate of more than 1 million acres (404,685 hectares) per year, with projected conversion “hotspots” projected in western regal fritillary habitats in North Dakota, South Dakota, Iowa, and Missouri (Lark et al. 2020, p. 3). This risk factor to the western regal fritillary is ongoing and projected to increase in the future (Service 2023, pp. 96-99, 134, 142, 245-255).

This risk factor applies only to the western subspecies. Herbicides are chemicals that may be used at least once in a growing season to control broadleaf weeds or grasses in crop fields. Herbicides are also commonly used to control woody vegetation and weeds in both public and private grasslands, including native prairie. If not used carefully, herbicides can indirectly impact regal fritillary populations by eliminating or reducing nectar and foodplants, especially if applied during critical periods of the western regal fritillary's lifecycle. Adverse effects can occur when herbicides are applied within regal fritillary habitat or nearby, where they can drift into western regal fritillary habitat (Dana 1997, p. 3; Stark et al. 2012, pp. 25, 27; Cordova et al. 2020, p. 5; Service 2023, p. 101). The effects of herbicide use may be especially problematic in areas where violets and nectar food sources are already limited, such as in small, isolated grassland patches. Additionally, herbicide drift from adjacent croplands into regal fritillary habitats may have limited and temporary effects to individuals and habitats by temporarily reducing the availability of violets and nectar sources. Active and inert ingredients in herbicides may also be toxic to western regal fritillary individuals.

The application of herbicides is most detrimental to the western regal fritillary when it is applied, often aerially, across large areas of native grasslands specifically to reduce native forbs, including violets, so that more grasses are available to graze livestock. This practice dramatically reduces the quantity of violets and nectar sources available to the western regal fritillary (Service 2023, pp. 101-102). This practice of broad herbicide application to reduce native forbs is ongoing, particularly on private lands in eastern South Dakota, the Flint Hills of Kansas, and Oklahoma (Service 2023, pp. 101-102). Unlike the potentially limited or temporary effects to habitats and individuals from herbicide drift, this practice directly exposes native grasslands to herbicides and could dramatically reduce the numbers of violets and nectar sources. The reduction and removal of violets and nectar sources in native grasslands may extirpate local colonies (Selby 2007, p. 36) and, if more widespread, could also decrease population abundance and resiliency. This risk factor is ongoing and is likely to increase in the future.

This risk factor applies to both the eastern and western subspecies. Invasive, nonnative (exotic) plants and woody vegetation may degrade the quality and quantity of native grasslands needed by both the eastern and western regal fritillary. These nonnative plants may spread into native habitats from purposefully planted areas to form self-perpetuating populations (Fulbright et al. 2013, p. 505). The invading plant species of concern and the magnitude, scope, and exposure to the eastern and western subspecies vary by location. Invasive grass species include Kentucky bluegrass ( Poa patrensis ) and smooth brome ( Bromus inermus ), which are the two primary species invading the Midwestern and Northern Great Plains prairies (Royer and Marrone 1992, p. 28; Selby 2007, p. 33; Gaskin et al. 2021, p. 236-237; Service 2023, pp. 104-105, 256). Woody plant species may include eastern red cedar ( Juniperus virginiana ) for the western subspecies and a variety of woody species from the surrounding forested habitat at FITG for the eastern subspecies, (Swartz 2021, pers. comm.; Service 2023 pp. 105-107; 256). Conservation efforts that target invasive plants, which may include fire, grazing, or mechanical or chemical controls, may reduce the stressor. However, invasive grasses and woody plant encroachment are challenging to control and known to degrade native grassland quality and quantity and may become more widespread, and potentially problematic, in the future.

Although an issue for both subspecies, woody encroachment is a primary risk factor for the eastern subspecies, where forested ecosystems are more prevalent and contributed to the historical decline of the eastern subspecies' grassland habitats. At FTIG, prescribed fire, mowing, and targeted brush cutting are used frequently to suppress shrub and tree sprouts, and without this important vegetation management, habitat for the eastern subspecies would be rapidly reforested and rendered unsuitable (Service 2023, p. 105). As with invasive grasses, over time, the continued degradation due to woody encroachment is likely to increasingly fragment and isolate habitats and is a risk factor to both the eastern and western subspecies.

This risk factor applies to both the eastern and western subspecies, with fire a risk factor for the eastern subspecies and fire, haying, and mowing a risk factor for the western subspecies. Fire, haying, mowing, and other activities, such as the manual or chemical removal of weeds or woody vegetation, are common disturbances in grasslands and are necessary to conserve these habitats, but they may negatively impact both the eastern and western subspecies (Selby 2007, p. 3). Unmanaged grasslands may become overgrown, invaded by woody vegetation or exotic species, or covered in thatch that inhibits floral diversity and suppresses violets and nectar sources. Although beneficial at the appropriate frequency, magnitude, and intensity, periodic disturbances can trample, crush, burn, or poison individuals, and temporarily or permanently remove important resource needs. When these periodic disturbances occur in large, contiguous native grassland landscapes, mortality typically does not result in population losses, as individuals may disperse to adjacent areas and affected habitats may eventually be recolonized.

However, periodic disturbances on smaller, more-isolated patches of grasslands, which are now the dominant patch size available for both subspecies, may extirpate local populations, and without nearby refugia, these disturbances can potentially preclude recolonization or cause population impacts lasting several years (Swengel 1996, p. 73). Timing and intensity can also determine the level of impact. For example, moderate-to-light grazing that maintains native grasslands and removes excessive thatch, controls invasive species, and stimulates native plant growth, is generally considered beneficial to the regal fritillary, but heavy grazing that does not promote native grasslands is not (Royer and Marrone 1992, p. 28; Service 2023, p. 110); fires on a 3- to 5-year rotation (Henderson et al. 2018, p. 41; McCullough et al. 2019, p. 9) may be beneficial, while shorter or longer intervals between burns are more detrimental (McCullough et al. 2019, p. 9), although annual burns may still provide some benefits to habitat compared to no burning (Henderson et al. 2018, p. 41). When applied on a landscape scale appropriately (proper timing, extent, intensity, frequency), these disturbances can minimize regal fritillary mortality while creating a shifting mosaic of habitats in various successional stages that provide a net benefit to the species' resiliency. However, when applied inappropriately, they pose a threat to both regal fritillary individuals and populations, particularly those that are already at risk due to other factors, such as their small size and isolation.

Currently, the Midwest populations of the western subspecies, because they occur in small, isolated patches, are vulnerable to the negative impacts of improperly applied periodic disturbances. Many populations in the Great Plains are also small, but the landscape is less fragmented; thus, disturbed sites are more easily recolonized when favorable vegetative conditions return. However, this could change in the future as more conversion and drought reduce and fragment habitats. At FTIG, the INRMP guides the periodic disturbances to benefit the eastern subspecies, but should these periodic disturbance activities stop, the resiliency of the eastern subspecies could decline significantly (Service 2023, p. 110).

This risk factor applies to both the eastern and western subspecies. By reducing precipitation, drought can significantly reduce violet and nectar sources, so drought is a risk factor for both the eastern and western subspecies. The regal fritillary is sensitive to prolonged, dry periods from drought, and population extirpations may occur, particularly in small, isolated habitats that lack heterogeneity (Service 2023, p. 106). With their long flight period and relatively long lifespan, adult regal fritillaries, particularly females, require a nearly continuous supply of nectar during summer and fall to survive and reproduce (Wagner et al. 1997, p. 266). Drought may decrease the availability of the needed flowering nectar plants (Royer and Marrone 1992, p. 25), so drought may increase an adult's risk of starvation, reduce breeding success, and increase risks associated with forced emigration in search of food. Spring droughts may reduce the availability of violets, so larvae may starve or their growth may be stunted (Service 2023, p. 106). Therefore, prolonged and extended dryness associated with drought during any season is a risk factor for regal fritillary individuals of all life stages. At FTIG in Pennsylvania, there is generally more moisture than in the West, so the eastern regal fritillary may be less vulnerable to drought than the western subspecies.

Specific impacts of climate change on pollinators are not well understood; however, expected changes forecasted for terrestrial species and communities include increased ambient temperature, changes to annual and seasonal precipitation patterns, increased frequency of extreme events, and changes to hydrologic regimes (Staudinger et al. 2013, p. 466). These climate changes may lead to decreased resource availability (due to mismatches in temporal and spatial co-occurrences), decreased availability and suitability of larval habitat (due to increased flooding or storms), and increased stress from overheating (due to higher temperatures) (Cohen et al. 2018, p. 226; Zografou et al. 2021, p. 3283). Based on the known biology and life history of the species, increasingly warmer temperatures may have effects such as interruption of winter diapause, which would result in energy expenditure and potentially reduced first instar survival; alteration of violet and/or nectar plant phenology, availability, or abundance, which would impact food resources for larval and adult stages; unusual post-winter diapause cold periods, which would impact larval survival; and direct mortality of regal fritillaries at all life stages due to excessive heat, drought, or severe storms. Despite having a wide climatic tolerance based on its range, the regal fritillary experiences very large fluctuations in annual numbers—even in populations with stable to increasing trends—suggesting that extreme weather can negatively impact regal fritillary abundance (Swengel and Swengel 2017, p. 19). Several populations in western Iowa, for example, were extirpated during extreme drought in the mid-2010s, with no perceived recovery as of the summer of 2021 (Hammond 2021, pers. comm.).

Climate variability may lead to shifts in geographic range, as has been reported for regal fritillary populations in Wisconsin and North Dakota (Swengel and Swengel 2017, p. 19), as well as decoupling pollinators from matching both host plant and nectar plant phenologies (Memmott et al. 2007, p. 712), as demonstrated in other butterfly species (Forister et al. 2010, pp. 2088-2089; Hickling et al. 2006, p. 452). Spring larval emergence may rely on suitable temperatures, photo period, or a combination of both, leading to larvae emerging when violets are older and less palatable. Drier summers could force regal fritillaries to leave otherwise suitable habitat in search of nectar sources. Other potential effects from climate change include increased flooding and storm events, which may directly reduce available larval habitat suitability ( e.g., violet abundance) (Goulson et al. 2015, p. 4). Finally, effects from climate change may increase stress on regal fritillaries in the future, further compounding pressures from other factors, including pathogens, nonnative species, and habitat loss (Goulson et al. 2015, pp. 4-5; Kerr et al. 2015, pp. 178-179; Williams and Osborne 2009, p. 371).

Our analysis of the past, current, and future influences on the needs of the eastern regal fritillary for long-term viability revealed that invasive plants, woody encroachment, and periodic disturbances from fire or other activities pose the greatest impact on the eastern subspecies' current and future viability. Drought and associated effects of climate change may also influence the viability of the eastern regal fritillary. For the western regal fritillary, grassland conversion, primarily due to agriculture; herbicides that are applied broadly (often aerially); drought; invasives grasses and woody vegetation; incompatible periodic disturbances from fire, haying, and mowing; and climate change factors pose the greatest impact on the western subspecies' current and future viability.

The State of Pennsylvania does not consider invertebrates for its State threatened and endangered species programs, so does not confer State-level protections to the eastern regal fritillary. A variety of conservation efforts have been and are implemented to benefit the eastern regal fritillary at FTIG. Since 2011, a regal fritillary captive-rearing program has attempted to reintroduce the eastern regal fritillary into suitable habitats off FTIG, although the attempts to establish a population have not yet been successful (Service 2023, p. 113). The INRMP, developed under the Sikes Act, helps guide conservation objectives and activities at FTIG specifically for the eastern regal fritillary, including increasing or maintaining population levels, nectar sources, and larval host plants. Conservation actions include extensive seasonal monitoring; habitat management using burning, mowing, and brush removal; and reintroduction efforts. Additionally, FTIG completed a candidate conservation agreement (CCA) to append to the INRMP that helps formally document regal fritillary butterfly conservation intentions at the military installation (FITG and Service 2024, entire). These conservation efforts have helped maintain grassland habitats at FTIG for the eastern subspecies. However, these conservation actions in the INRMP and draft CCA are not regulatory or binding and could stop with changing funding or priorities (PADMVA 2021, pp. 20, 31; Swartz 2022, pers. comm; FITG and Service 2024, entire). As a result, there are no binding and enforceable regulatory mechanisms that address threats to the eastern regal fritillary.

The States of Indiana and Wisconsin have assigned the western regal fritillary State-level protections as an endangered species and the State of Illinois recognizes the species as a threatened species (Service 2023, p. 179). The States of Iowa, Minnesota and Wyoming identify the western regal fritillary as a species of concern (Service 2023, p. 179. These designations may allow State agencies to develop programs to manage and conserve nongame and endangered species, but they do not provide binding and enforceable regulatory mechanisms that may reduce threats to the western regal fritillary. Additionally, conservation measures and actions may occur locally in many areas to benefit the western regal fritillary, but most are likely to be voluntary and may not be able to ameliorate or mitigate the identified threats to the species (Service 2023, pp. 116-117). These actions often depend on limited sources of funding and may not necessarily conducted with the needs and life history of the regal fritillary in mind and may or may not be beneficial to the subspecies (Service 2023, pp. 116-117). Appropriate haying, grazing, and burning are generally known to be beneficial to regal fritillaries by promoting native grassland habitats, and these actions do occur under all types of land ownership. However, land use activities conducted without knowledge or consideration for the subspecies' life-history and habitat needs can be detrimental to individuals and populations, particularly on small, isolated habitat patches. Additionally, activities are not typically conducted in a coordinated manner among landowners or on a scale large enough to improve the resiliency, redundancy, or representation of the western subspecies.

To evaluate resiliency for the eastern regal fritillary, we evaluated the current condition of several habitat factors (native grasslands, riparian and wetland areas, ambient temperature, precipitation) and two demographic factors (population trend and abundance) (Service 2023, pp. 120-131). Currently, the eastern regal fritillary is found in one population, and based on our evaluation of the habitat and demographic factors, that single population currently has low resiliency and provides the subspecies' redundancy and representation. The single population is found on FTIG military base in Pennsylvania, where ongoing management activities to benefit the subspecies are conducted through an INRMP on approximately 457 acres (185 hectares). These management activities have helped maintain grassland habitats for the eastern regal fritillary, such that many of the available habitats are in good condition. FITG has monitored the eastern regal fritillary on the military base since 1992 (Ferster 2005, p. 8). The population peaked in 2014 with approximately 5,400 individuals, but declined starting in 2017 to approximately 800 individuals, and the population size has never rebounded to its high numbers from 2014 (Swartz 2022, pers. comm.; Service 2023, p. 64). As a result, the abundance and growth trend are currently both in very low condition, so the eastern subspecies has low resiliency (Service 2023, pp. 123, 126-128). Additionally, military activities and periodic disturbance activities such as fire, which can benefit the eastern subspecies by reducing woody encroachment, may also present a risk to the subspecies if they are discontinued or if they are too frequent, intense, or catastrophic. Active military exercises and other activities occur without consideration of the subspecies elsewhere in grassland habitats at FTIG. The eastern subspecies' resiliency and redundancy are limited by the condition of the subspecies' small, narrowly distributed habitats and depend on the reduction of its primary threat, woody encroachment, through management and other voluntary activities. The eastern subspecies is different genetically and morphologically than the western subspecies, and the east representative unit provides a unique, more mesic, ecological type. The eastern regal fritillary's small population size, narrow distribution, and limited ecological and genetic diversity indicate that the eastern subspecies is currently vulnerable to stochastic events, catastrophes, and environmental change.

To evaluate resiliency for the western regal fritillary, we evaluated the current condition of several habitat factors (native grasslands, riparian and wetland areas, ambient temperature, precipitation) and two demographic factors (population trend and abundance) (Service 2023, pp. 120-131). Currently, the western subspecies has 21 populations, or analytical units in the SSA, distributed across 3 representation units, which feature a diversity of climates, habitats, and genetics. Based on our evaluation of the habitat and demographic factors, of the 21 populations, 3 currently have high resiliency, 7 have medium resiliency, 10 have low resiliency, and 1 is currently functionally extirpated with no resiliency, although it supports habitats and has recent observations (Service 2023, pp. 16, 124-126). Populations with high resiliency have better habitat and demographic conditions than populations with medium or low resiliency, so are better able to withstand stochastic events. Populations with medium resiliency are about as likely as not to withstand a stochastic event, those with low resiliency are less likely to withstand a stochastic event, and those with no resiliency are considered functionally extirpated, so unlikely to withstand a stochastic event. The three populations with high resiliency are in the Northern and Central Great Plains representation units, and no populations currently have very high or very low resiliency (Service 2023, pp. 16, 128). All the populations in the Midwest representation units currently have low resiliency because of generally poor habitat conditions following the conversion of these areas to agriculture and other development. Additionally, populations in the Midwest exhibit relatively less genetic diversity than those in the Northern Great Plains or Central Great Plains, an indication of their fragmentation and isolation (Service 2023, pp. 21, 129). However, across the entire Northern and Central Great Plains representation units, based on genetics, the western regal fritillary is considered one, large population with high gene flow over hundreds of kilometers (Williams et al. 2003, pp. 13, 14). The 21 populations are distributed across portions of 14 States. As a result, the western subspecies currently has levels of resiliency, redundancy, and representation that make it less vulnerable to extinction.

As part of the SSA, we developed three future condition scenarios to capture the range of uncertainties regarding future threats to and the projected responses of the eastern and western subspecies of regal fritillary. Our scenarios included a continuation scenario, which incorporated the current risk factors continuing on the same trajectory as they are now. We also evaluated two future scenarios that incorporated varying levels of increasing risk factors with elevated negative effects on populations of the eastern and western subspecies. However, because we determined that the current condition of the eastern subspecies is consistent with an endangered subspecies (see Eastern Subspecies: Determination of Status, below), we are not presenting the results of our future conditions analysis for the eastern subspecies in this proposed rule. Please refer to the SSA report (Service 2023, pp. 132-152) for the full analysis of future conditions for both subspecies.

We projected the future condition of the western subspecies of regal fritillary under three plausible future scenarios across the next 50 years, to approximately 2075. This 50-year timeframe for our future projections accounts for approximately 50 annual regal fritillary generations and is an adequate time period to assess the response of populations to stressors and conservation efforts, given that the historical range of the eastern subspecies contracted to its current distribution within approximately 50 years. It is also a time period for which we can reasonably project climate conditions based on the best available climate models across the range of the western subspecies.

The future scenarios described in the SSA report represent three possible future conditions based on projected climate conditions and plausible states of the threats for the western regal fritillary, as summarized in Risk Factors for the Eastern and Western Subspecies, above. The future scenarios project the threats into the future and consider the impacts those threats could have on the viability of the western subspecies. We apply the concepts of resiliency, redundancy, and representation to the future scenarios to describe the range of plausible future conditions of the western subspecies. Uncertainty is inherent in any projection of future condition, so we must consider plausible scenarios to make our determinations. When assessing the future, viability is not a specific state, but rather a continuous measure of the likelihood that the subspecies will sustain populations over time.

We included climate change impacts in our future scenarios as a factor that would add to the negative effects of the primary threats to the western subspecies and its habitat. Climate change is expected to increase ambient temperatures, reduce precipitation, and increase the frequency and duration of drought across the overall range of the western subspecies. Warmer ambient temperatures may interrupt winter diapause, which would result in energy expenditure and potentially reduced first instar survival; alter violet and nectar plant phenology, availability, or abundance, which would impact food resources for larvae and adults; result in unusual post-winter diapause cold periods, which would impact larval survival; and direct mortality of regal fritillaries at all life stages due to excessive heat, drought, or severe storms. Increased frequency and duration of drought may reduce the availability of violets and nectar sources. We used the best available climate data and models, including representative concentration pathways (RCPs) 4.5 and 8.5 and underlying temperature and precipitation models, to project the plausible outcomes for these factors, which were incorporated into our three future scenarios (Service 2023, pp. 133-136, 141-143). We summarize the results of our future conditions analysis for the western regal fritillary below.

Our future scenarios analysis for the western regal fritillary revealed that in 50 years, stressors will increase at their current rates of increase, or will increase moderately or significantly more than their current rates of increase. When stressors continue at their current rates, we projected that grassland habitats will continue to become smaller, more fragmented, and isolated, such that resiliency declines for at least four of the populations in 50 years (Service 2023, pp. 141-152). Although the number, distribution, and diversity of western subspecies populations decline only slightly under this future scenario, the scenario still represents increased risk for the western subspecies with the declines in resiliency. With a moderate future increase in stressors, the quality and quantity of habitats decline further such that resiliency declines for up to 11 populations, with drops from medium to low resiliency, and some to very low resiliency (Service 2023, pp. 141-152). Finally, with the most significant projected increase in stressors, 10 of the 21 populations lose resiliency and become extirpated, 7 populations have very low resiliency, 1 population has low resiliency, and only 3 have medium resiliency (Service 2023, pp. 141-152). This future scenario represents a large decline in resiliency, redundancy, and representation for the western subspecies in 50 years, with a corresponding decline in viability. Across all of our plausible future scenarios, our analysis revealed that the western regal fritillary is at a greater risk of extinction in the future.

We note that, by using the SSA framework to guide our analysis of the scientific information documented in the SSA report, we have analyzed the cumulative effects of identified threats and conservation actions on the species. To assess the current and future condition of the species, we evaluate the effects of all the relevant factors that may be influencing the species, including threats and conservation efforts. Because the SSA framework considers not just the presence of the factors, but the degree to which the factors collectively influence risk to the entire species, our assessment integrates the cumulative effects of the factors and replaces a standalone cumulative-effects analysis.

Section 4 of the Act (16 U.S.C. 1533) and its implementing regulations (50 CFR part 424) set forth the procedures for determining whether a species meets the definition of an endangered species or a threatened species. The Act defines an “endangered species” as a species in danger of extinction throughout all or a significant portion of its range, and a “threatened species” as a species likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range. The Act requires that we determine whether a species meets the definition of an endangered species or a threatened species because of any of the following factors: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence.

After evaluating threats to the eastern and western regal fritillary and assessing the cumulative effect of the threats under the Act's section 4(a)(1) factors, we found that both subspecies have declined in overall abundance and distribution. Historically, populations of the regal fritillary functioned on a vast, metapopulation scale and were abundant and broadly distributed, particularly in the Midwest and Great Plains. Millions of individuals likely occupied the North American prairies prior to establishment of European agriculture in the 1800s (Hammond and McCorkle 1983(84), p. 219). Natural disturbance processes including climate, grazing, and fire maintained the open grassland habitats, and there were enough violet and nectar components for the regal fritillary. This vast range may have facilitated an eastward range expansion, perhaps via coastal grasslands, where the regal fritillary opportunistically moved into inland habitats created and maintained by human activities (Service 2023, p. 131).

Today, grassland patches of adequate size, diversity, and connectivity are significantly reduced, both in number and proximity, interrupting the landscape-level scales at which the regal fritillary historically functioned. Accessibility to suitable habitats has become increasingly restrictive for the eastern and western regal fritillary, as many remaining suitable grassland patches are small and isolated, primarily the result of conversion in the West and woody encroachment in the East. The eastern subspecies is extirpated from nearly every formerly known occupied eastern location and is confined to one small population that is extremely vulnerable to environmental and demographic stochasticity. For the western subspecies, a small fraction, less than one percent, of the historically vast tallgrass prairies of the Midwest remains today, mostly as grassland remnants that are severely fragmented and isolated (Samson and Knopf 1994, p. 418, Service 2023, p. 97). Conditions at the westernmost extent of the western subspecies' overall range are currently not as severe, as large mixed-grass prairies remain, but much of these grasslands have been or could be converted to agriculture and other development. In the future, the climate in the West is projected to be drier and warmer, and important resource needs, such as violets and native grasses, may become limited. Without large, intact, contiguous grasslands, dispersals of individuals from occupied habitats are often already dead ends, as individuals move into a matrix that may be composed of unsuitable agricultural fields where they are unable to find the resources they need to survive and establish the next annual generation. For both the eastern and western subspecies, the risk of genetic collapses increases without regular successful dispersal events, and the eastern regal fritillary has already experienced restricted gene flow. The western regal fritillary has reduced genetic diversity in the Midwest. Natural periodic disturbances that historically maintained the shifting mosaic of habitats on the landscape scale have been replaced with permanent land use changes and land use management regimes that, when applied inappropriately, have reduced or eliminated regal fritillary populations. As a result, both subspecies are increasingly vulnerable to stochastic events and synergistic processes that have significantly greater potential to cause population extirpations that may outpace recolonization rates.

The eastern regal fritillary has declined significantly in overall distribution and abundance since the 1930s. Once broadly distributed across the eastern United States, the eastern subspecies is now found only in one population on approximately 457 acres (185 hectares) of remnant grasslands on FTIG in Pennsylvania. Due to the small size of the occupied habitats and the single population, the eastern regal fritillary currently has low resiliency, limited redundancy, and reduced ecological and genetic diversity (representation). As a result, the eastern subspecies is vulnerable to stochastic and catastrophic events, such as hot and dry summers, long and cold winters, and destructive fires. The eastern subspecies' low level of resiliency, coupled with its limited redundancy and representation and ongoing and immediate threats currently results in a high risk of extinction for the eastern regal fritillary.

The remaining eastern subspecies' grassland habitats at FTIG depend on the ongoing reduction of woody encroachment through active management. These activities are critical to the viability of the eastern regal fritillary and have helped ensure that the eastern subspecies remains in this area in contrast to its historical extirpation throughout much of its overall range. Active management at FTIG, whether intentional or unintentional, has reduced and continues to reduce habitat loss and fragmentation from woody encroachment, such that FTIG is now the lone site where the eastern subspecies is still found. Although conservation activities at FTIG are ongoing and have benefited the eastern subspecies by maintaining grassland habitats, they are implemented only in specific areas and could stop or change at any time depending on funding and priorities, thus increasing the subspecies' vulnerability. Military activities and periodic disturbance activities such as fire, which can benefit the eastern subspecies by reducing woody encroachment, may also present a risk to the subspecies if they are discontinued or if they are too frequent, intense, or catastrophic. As a result, the eastern regal fritillary is vulnerable to extinction, not only because of its limited abundance, distribution, and diversity, but also by its complete reliance on important and effective land management activities that are not guaranteed to continue.

Our analysis of the eastern subspecies' current condition, as well as the conservation efforts discussed above, show that the eastern regal fritillary is in danger of extinction throughout all of its range due to the severity and immediacy of threats currently impacting its single population (see Risk Factors for the Eastern and Western Subspecies, above). The single population is isolated, has limited potential for natural recolonization, and has a high risk of extirpation from stochastic and catastrophic events, so the risk of extinction for the eastern regal fritillary is high; therefore, the species meets the definition of an endangered species and is not a threatened species.

Under the Act and our implementing regulations, a subspecies may warrant listing if it is in danger of extinction or likely to become so within the foreseeable future throughout all or a significant portion of its range. We have determined that the eastern subspecies of regal fritillary is in danger of extinction throughout all of its range and accordingly did not undertake an analysis of any significant portion of its range. Because the eastern subspecies of regal fritillary warrants listing as endangered throughout all of its range, our determination does not conflict with the decision in Center for Biological Diversity v. Everson, 435 F. Supp. 3d 69 (D.D.C. 2020) ( Everson ), which vacated the provision of the Final Policy on Interpretation of the Phrase “Significant Portion of Its Range” in the Endangered Species Act's Definitions of “Endangered Species” and “Threatened Species” (hereafter “Final Policy”; 79 FR 37578, July 1, 2014) that provided that if the Service had determined that a species was threatened throughout all of its range, the Service would not analyze whether the species was endangered in a significant portion of its range.

Our review of the best available scientific and commercial information indicates that the eastern regal fritillary meets the Act's definition of an endangered species. Therefore, we propose to list the eastern regal fritillary as an endangered species in accordance with sections 3(6) and 4(a)(1) of the Act.

Currently, the western regal fritillary has 21 populations distributed across portions of 14 States and 3 representation units, which feature a diversity of climates, habitats, and genetics. Three populations have high resiliency, 7 have medium resiliency, 10 have low resiliency, and 1 has no resiliency. All the populations in the Midwest representative unit currently have low resiliency following the conversion of grasslands to agriculture and development. Populations in North and South Dakota, eastern Montana, eastern Wyoming, the Sandhills in west-central Nebraska, and the Flint Hills in eastern Kansas, currently have high resiliency, because of the high-quality condition of their habitat and demographic factors. Genetic exchange occurs across much of the Northern and Central Great Plains, indicating that enough suitable habitats currently remain such that dispersals and recolonizations help maintain the landscape-level metapopulation structure for the western regal fritillary.

We considered whether the western regal fritillary is presently in danger of extinction throughout all of its range and determined that it is not. The current conditions as assessed in our SSA report show that there are three populations with high resiliency and seven populations with medium resiliency distributed broadly across two large representation units. There are an additional eight populations in the Midwest representation unit with low resiliency and reduced ecological and genetic diversity, so although this area contributes less to the overall viability of the western subspecies, it still provides some resiliency and redundancy for the subspecies. Across all three representation units, there are multiple, sufficiently resilient populations distributed across a large, ecologically diverse area. As a result, the western regal fritillary currently has sufficient resiliency, redundancy, and representation to withstand stochastic and catastrophic events and environmental change. Although threats are currently acting on the western subspecies and many of those threats are expected to continue into the future, we did not find that the subspecies is currently in danger of extinction throughout all of its range.

In the future, as stressors, such as conversion to agriculture, invasive plants, and drought, continue to reduce the quality and quantity of native grasslands, we expect western regal fritillary populations to be at an increased risk of extirpation. We project the least amount of decline in the western subspecies' viability if the stressors continue at their current rates and the greatest decline if stressors increase significantly. Across all of our future projections, fewer populations will have high and medium resiliency, with increases in the number and distribution of populations with low, very low, or no resiliency (extirpation). With increasing threats in the future, grassland habitats will become smaller, more isolated, and more fragmented, and individuals will be less able to disperse and recolonize, so we project overall declines in the resiliency, redundancy, and representation of the western subspecies in 50 years. As a result, we expect that, in the foreseeable future, the western regal fritillary will be at an increased risk of extirpation.

According to our assessment of plausible future scenarios in the SSA report, the western subspecies is likely to become an endangered subspecies within the foreseeable future of 50 years throughout all of its range. Our future scenarios help address future uncertainty by describing plausible outcomes for the primary risk factors to the western subspecies. Fifty years encompasses 50 annual generations of the western regal fritillary and a time period when stressors are reasonably expected to change and we can make reasonably reliable predictions about the threats and the western regal fritillary's responses to those threats. In the foreseeable future, we expect more grasslands to be converted to agriculture and development and to become drier, as ambient temperatures increase and droughts increase in intensity, magnitude, and frequency. We expect increases in invasive plants, broad herbicide application, and periodic disturbances. As a result, we expect additional reductions in the size and distribution of large, intact blocks of grasslands and the underlying resources needed by the western regal fritillary, including violets, bunch grasses, and nectar sources. Violets and nectar sources become more scarce as herbicides are broadly applied to reduce forbs in the remaining tracts of grasslands. Climate change could further exacerbate the effects of drought. As habitats become smaller and more isolated, metapopulation processes could fail, with subsequent declines in the resiliency of the remaining populations of the western subspecies, as well as the redundancy and representation of the subspecies, and we expect the western regal fritillary to become more vulnerable to stochastic and catastrophic events and environmental change. Therefore, the western regal fritillary is likely to become an endangered subspecies within the foreseeable future throughout all of its range.

After evaluating threats to the western subspecies and assessing the cumulative effect of the threats under the Act's section 4(a)(1) factors, we find that the viability of the western subspecies will continue to decline in the next 50 years so that the subspecies is likely to become in danger of extinction within the foreseeable future throughout all of its range due to the projected loss and fragmentation of grassland habitats from conversion to agriculture and development, drought, invasive and woody plants, the broad application of herbicides, and the synergistic effects of these threats with climate change. Thus, after assessing the best available information, we conclude that the western subspecies of regal fritillary is not currently in danger of extinction but is likely to become in danger of extinction within the foreseeable future throughout all of its range.

Under the Act and our implementing regulations, a species may warrant listing if it is in danger of extinction or likely to become so in the foreseeable future throughout all or a significant portion of its range. The court in Center for Biological Diversity v. Everson, 435 F. Supp. 3d 69 (D.D.C. 2020) ( Everson ), vacated the provision of the Final Policy on Interpretation of the Phrase “Significant Portion of Its Range” in the Endangered Species Act's Definitions of “Endangered Species” and “Threatened Species” (hereafter “Final Policy”; 79 FR 37578, July 1, 2014) that provided if the Services determine that a species is threatened throughout all of its range, the Services will not analyze whether the species is endangered in a significant portion of its range.

Therefore, we proceed to evaluating whether the western subspecies is endangered in a significant portion of its range—that is, whether there is any portion of the western subspecies' range for which both (1) the portion is significant; and (2) the subspecies is in danger of extinction in that portion. Depending on the case, it might be more efficient for us to address the “significance” question or the “status” question first. We can choose to address either question first. Regardless of which question we address first, if we reach a negative answer with respect to the first question that we address, we do not need to evaluate the other question for that portion of the subspecies' range.

Following the court's holding in Everson, we now consider whether there are any significant portions of the western subspecies' range where the subspecies is in danger of extinction now ( i.e., endangered). In undertaking this analysis for the western regal fritillary, we choose to address the status question first—we consider information pertaining to the geographic distribution of the western subspecies and the threats that it faces to identify portions of the range where the western regal fritillary may be endangered.

We evaluated the range of the western regal fritillary to determine if the subspecies is in danger of extinction now in any portion of its range. The range of a subspecies can theoretically be divided into portions in an infinite number of ways. We focused our analysis on portions of the western subspecies' range that may be in danger of extinction ( i.e., meet the Act's definition of an endangered species). For the western regal fritillary, we considered whether the threats or their effects on the subspecies are greater in any biologically meaningful portion of the subspecies' range than in other portions, such that the subspecies is in danger of extinction now in that portion.

We examined the range of the western subspecies for biologically meaningful portions that may be at a higher risk of extirpation, as reflected by current resiliency of the 21 populations. Currently, 10 of the 21 populations have low resiliency, so they are at a greater risk of extirpation than the populations with more resiliency. These 10 populations are geographically concentrated along the eastern edge of the western subspecies' overall range. Eight of these populations with low resiliency make up the Midwest representation unit, which was historically dominated by vast tallgrass prairies, but today is an agriculturally dominated landscape with prairie remnants existing primarily as small, isolated patches. The other two populations currently with low resiliency, the Lake Agassiz Plain and Ozark Highlands populations, immediately adjoin the Midwest representation unit, so were included in our potential portion.

We then considered whether this biologically meaningful portion of 10 populations with low resiliency may be at a higher risk of extirpation. We examined the following threats, for the reasons described above: grassland conversion, invasive plants, broad application of herbicides, periodic disturbances, drought, climate change, and cumulative effects. We concluded that although the populations in this portion have low resiliency, largely the result of low and very low conditions of the large, contiguous blocks of native grasslands, reproduction and recolonization still occurs with abundance and growth trends ranging from low to medium conditions (Service 2023, p. 125). Additionally, the portion has sufficient redundancy and representation across the 10 populations such that it is not currently in danger of extinction. The 10 populations cover a wide geographic area that spans portions of 6 States across a variety of climatic and habitat types from north-to-south and east-to-west, such that there is no stochastic or catastrophic event that would extirpate the portion in the near term. Therefore, we conclude that the portion does not have a different status from the remainder of the western subspecies' range. Because we determined that this portion does not have a different status, we did not need to assess its potential significance. As a result, we found no portion of the western subspecies' range where the biological condition of the subspecies differs from its condition elsewhere in its range such that the status of the subspecies in that portion differs from any other portion of the subspecies' range.

Therefore, no portion of the western subspecies' range provides a basis for determining that the subspecies is in danger of extinction in a significant portion of its range, and we determine that the western regal fritillary is likely to become in danger of extinction within the foreseeable future throughout all of its range. This does not conflict with the courts' holdings in Desert Survivors v. U.S. Department of the Interior, 321 F. Supp. 3d 1011, 1070-74 (N.D. Cal. 2018) and Center for Biological Diversity v. Jewell, 248 F. Supp. 3d 946, 959 (D. Ariz. 2017) because, in reaching this conclusion, we did not apply the aspects of the Final Policy, including the definition of “significant” that those court decisions held to be invalid.

Our review of the best available scientific and commercial information indicates that the western subspecies of regal fritillary meets the Act's definition of a threatened species. Therefore, we propose to list the western subspecies of regal fritillary as a threatened species in accordance with sections 3(20) and 4(a)(1) of the Act.

Conservation measures provided to species listed as endangered or threatened species under the Act include recognition as a listed species, planning and implementation of recovery actions, requirements for Federal protection, and prohibitions against certain practices. Recognition through listing results in public awareness, and conservation by Federal, State, Tribal, and local agencies, private organizations, and individuals. The Act encourages cooperation with the States and other countries and calls for recovery actions to be carried out for listed species. The protection required by Federal agencies, including the Service, and the prohibitions against certain activities are discussed, in part, below.

The primary purpose of the Act is the conservation of endangered and threatened species and the ecosystems upon which they depend. The ultimate goal of such conservation efforts is the recovery of these listed species, so that they no longer need the protective measures of the Act. Section 4(f) of the Act calls for the Service to develop and implement recovery plans for the conservation of endangered and threatened species. The goal of this process is to restore listed species to a point where they are secure, self-sustaining, and functioning components of their ecosystems.

The recovery planning process begins with development of a recovery outline made available to the public soon after a final listing determination. The recovery outline guides the immediate implementation of urgent recovery actions while a recovery plan is being developed. Recovery teams (composed of species experts, Federal and State agencies, nongovernmental organizations, and stakeholders) may be established to develop and implement recovery plans. The recovery planning process involves the identification of actions that are necessary to halt and reverse the species' decline by addressing the threats to its survival and recovery. The recovery plan identifies recovery criteria for review of when a species may be ready for reclassification from endangered to threatened (“downlisting”) or removal from protected status (“delisting”), and methods for monitoring recovery progress. Recovery plans also establish a framework for agencies to coordinate their recovery efforts and provide estimates of the cost of implementing recovery tasks. Revisions of the plan may be done to address continuing or new threats to the species, as new substantive information becomes available. The recovery outline, draft recovery plan, final recovery plan, and any revisions will be available on our website as they are completed ( https://www.fws.gov/program/endangered-species ), or from our Pennsylvania or South Dakota Ecological Services Field Offices (see FOR FURTHER INFORMATION CONTACT ).

Implementation of recovery actions generally requires the participation of a broad range of partners, including other Federal agencies, States, Tribes, nongovernmental organizations, businesses, and private landowners. Examples of recovery actions include habitat restoration ( e.g., restoration of native vegetation), research, captive propagation and reintroduction, and outreach and education. The recovery of many listed species cannot be accomplished solely on Federal lands because their ranges may occur primarily or solely on non-Federal lands. To achieve recovery of these species requires cooperative conservation efforts on private, State, and Tribal lands.

If these subspecies are listed, funding for recovery actions will be available from a variety of sources, including Federal budgets, State programs, and cost-share grants for non-Federal landowners, the academic community, and nongovernmental organizations. In addition, pursuant to section 6 of the Act, the State of Pennsylvania would be eligible for Federal funds to implement management actions that promote the protection or recovery of the eastern regal fritillary. The States of Arkansas, Colorado, Illinois, Indiana, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, Oklahoma, South Dakota, Wisconsin, and Wyoming would be eligible for Federal funds to implement management actions that promote the protection or recovery of the western regal fritillary. Information on our grant programs that are available to aid species recovery can be found at: https://www.fws.gov/service/financial-assistance.

Although the eastern and western regal fritillary are only proposed for listing under the Act at this time, please let us know if you are interested in participating in recovery efforts for these subspecies. Additionally, we invite you to submit any new information on these subspecies whenever it becomes available and any information you may have for recovery planning purposes (see FOR FURTHER INFORMATION CONTACT ).

Section 7 of the Act is titled, “Interagency Cooperation” and mandates all Federal action agencies to use their existing authorities to further the conservation purposes of the Act and to ensure that their actions are not likely to jeopardize the continued existence of listed species or adversely modify critical habitat. Regulations implementing section 7 are codified at 50 CFR part 402.

Section 7(a)(2) states that each Federal action agency shall, in consultation with the Secretary, ensure that any action they authorize, fund, or carry out is not likely to jeopardize the continued existence of a listed species or result in the destruction or adverse modification of designated critical habitat. Each Federal agency shall review its action at the earliest possible time to determine whether it may affect listed species or critical habitat. If a determination is made that the action may affect listed species or critical habitat, formal consultation is required (see 50 CFR 402.14(a)), unless the Service concurs in writing that the action is not likely to adversely affect listed species or critical habitat. At the end of a formal consultation, the Service issues a biological opinion containing its determination of whether the Federal action is likely to result in jeopardy or adverse modification.

In contrast, section 7(a)(4) of the Act requires Federal agencies to confer with the Service on any action which is likely to jeopardize the continued existence of any species proposed to be listed under the Act or result in the destruction or adverse modification of critical habitat proposed to be designated for such species. Although the conference procedures are required only when an action is likely to result in jeopardy or adverse modification, action agencies may voluntarily confer with the Service on actions that may affect species proposed for listing or critical habitat proposed to be designated. In the event that the subject species is listed or the relevant critical habitat is designated, a conference opinion may be adopted as a biological opinion and serve as compliance with section 7(a)(2) of the Act.

Examples of discretionary actions for the eastern and western regal fritillary that may be subject to conference and consultation procedures under section 7 are land management or other landscape-altering activities on Federal lands administered by the Natural Resources Conservation Service, the Bureau of Land Management, the National Park Service, and the Department of Defense, as well as actions on State, Tribal, local, or private lands that require a Federal permit (such as a permit from the U.S. Army Corps of Engineers under section 404 of the Clean Water Act (33 U.S.C. 1251 et seq. ) or a permit from the Service under section 10 of the Act) or that involve some other Federal action (such as funding from the Federal Highway Administration, Federal Aviation Administration, or Federal Emergency Management Agency). Federal actions not affecting listed species or critical habitat—and actions on State, Tribal, local, or private lands that are not federally funded, authorized, or carried out by a Federal agency—do not require section 7 consultation. Federal agencies should coordinate with the local Service Field Office (see FOR FURTHER INFORMATION CONTACT ) with any specific questions on section 7 consultation and conference requirements.

The Act and its implementing regulations set forth a series of general prohibitions and exceptions that apply to endangered wildlife. The prohibitions of section 9(a)(1) of the Act, and the Service's implementing regulations codified at 50 CFR 17.21, make it illegal for any person subject to the jurisdiction of the United States to commit, to attempt to commit, to solicit another to commit or to cause to be committed any of the following: (1) import endangered wildlife into, or export from, the United States; (2) take (which includes harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct) endangered wildlife within the United States or on the high seas; (3) possess, sell, deliver, carry, transport, or ship, by any means whatsoever, any such wildlife that has been taken illegally; (4) deliver, receive, carry, transport, or ship in interstate or foreign commerce in the course of commercial activity; or (5) sell or offer for sale in interstate or foreign commerce. Certain exceptions to these prohibitions apply to employees or agents of the Service, the National Marine Fisheries Service, other Federal land management agencies, and State conservation agencies.

We may issue permits to carry out otherwise prohibited activities involving endangered wildlife under certain circumstances. Regulations governing permits for endangered wildlife are codified at 50 CFR 17.22. With regard to endangered wildlife, a permit may be issued for scientific purposes, for enhancing the propagation or survival of the species, or for take incidental to otherwise lawful activities. The statute also contains certain exemptions from the prohibitions, which are found in sections 9 and 10 of the Act.

Section 4(d) of the Act contains two sentences. The first sentence states that the Secretary shall issue such regulations as she deems necessary and advisable to provide for the conservation of species listed as threatened species. Conservation is defined in the Act to mean the use of all methods and procedures which are necessary to bring any endangered species or threatened species to the point at which the measures provided pursuant to the Act are no longer necessary. Additionally, the second sentence of section 4(d) of the Act states that the Secretary may by regulation prohibit with respect to any threatened species any act prohibited under section 9(a)(1), in the case of fish or wildlife, or section 9(a)(2), in the case of plants. With these two sentences in section 4(d), Congress delegated broad authority to the Secretary to determine what protections would be necessary and advisable to provide for the conservation of threatened species, and even broader authority to put in place any of the section 9 prohibitions for a given species.

The courts have recognized the extent of the Secretary's discretion under this standard to develop rules that are appropriate for the conservation of a species. For example, courts have upheld, as a valid exercise of agency authority, rules developed under section 4(d) that included limited prohibitions against takings (see Alsea Valley Alliance v. Lautenbacher, 2007 WL 2344927 (D. Or. 2007); Washington Environmental Council v. National Marine Fisheries Service, 2002 WL 511479 (W.D. Wash. 2002)). Courts have also upheld 4(d) rules that do not address all of the threats a species faces (see State of Louisiana v. Verity, 853 F.2d 322 (5th Cir. 1988)). As noted in the legislative history when the Act was initially enacted, “once an animal is on the threatened list, the Secretary has an almost infinite number of options available to [her] with regard to the permitted activities for those species. [She] may, for example, permit taking, but not importation of such species, or [she] may choose to forbid both taking and importation but allow the transportation of such species” (H.R. Rep. No. 412, 93rd Cong., 1st Sess. 1973).

The provisions of this species' proposed protective regulations under section 4(d) of the Act are one of the many tools that we would use to promote the conservation of the western regal fritillary. Nothing in 4(d) rules change in any way the recovery planning provisions of section 4(f) of the Act, the consultation requirements under section 7 of the Act, or the ability of the Service to enter into partnerships for the management and protection of the western regal fritillary. As mentioned previously in Available Conservation Measures, section 7(a)(2) of the Act requires Federal agencies, including the Service, to ensure that any action they authorize, fund, or carry out is not likely to jeopardize the continued existence of any endangered species or threatened species or result in the destruction or adverse modification of designated critical habitat of such species. In addition, even before the listing of any species or the designation of its critical habitat is finalized, section 7(a)(4) of the Act requires Federal agencies to confer with the Service on any agency action which is likely to jeopardize the continued existence of any species proposed to be listed under the Act or result in the destruction or adverse modification of critical habitat proposed to be designated for such species. These requirements are the same for a threatened species regardless of what is included in its 4(d) rule.

Section 7 consultation is required for Federal actions that “may affect” a listed species regardless of whether take caused by the activity is prohibited or excepted by a 4(d) rule (“blanket rule” or species-specific 4(d) rule). A 4(d) rule does not change the process and criteria for informal or formal consultations and does not alter the analytical process used for biological opinions or concurrence letters. For example, as with an endangered species, if a Federal agency determines that an action is “not likely to adversely affect” a threatened species, this will require the Service's written concurrence (50 CFR 402.13(c)). Similarly, if a Federal agency determinates that an action is “likely to adversely affect” a threatened species, the action will require formal consultation with the Service and the formulation of a biological opinion (50 CFR 402.14(a)). Because consultation obligations and processes are unaffected by 4(d) rules, we may consider developing tools to streamline future intra-Service and inter-Agency consultations for actions that result in forms of take that are not prohibited by the 4(d) rule (but that still require consultation). These tools may include consultation guidance, Information for Planning and Consultation effects determination keys, template language for biological opinions, or programmatic consultations.

Exercising the Secretary's authority under section 4(d) of the Act, we have developed a proposed rule that is designed to address the western subspecies' conservation needs. As discussed previously in Summary of Biological Status and Threats, we have concluded that the western regal fritillary is likely to become in danger of extinction within the foreseeable future primarily due to the loss and fragmentation of grasslands through conversion by agriculture and development, the broadcast application of herbicides, invasive and woody plants, periodic disturbances, drought, and the synergistic effects of climate change. Section 4(d) requires the Secretary to issue such regulations as she deems necessary and advisable to provide for the conservation of each threatened species and authorizes the Secretary to include among those protective regulations any of the prohibitions that section 9(a)(1) of the Act prescribes for endangered species. We are not required to make a “necessary and advisable” determination when we apply or do not apply specific section 9 prohibitions to a threatened species (In re: Polar Bear Endangered Species Act Listing and 4(d) Rule Litigation, 818 F. Supp. 2d 214, 228 (D.D.C. 2011) (citing Sweet Home Chapter of Cmtys. for a Great Or. v. Babbitt, 1 F.3d 1, 8 (D.C. Cir. 1993), rev'd on other grounds, 515 U.S. 687 (1995))). Nevertheless, even though we are not required to make such a determination, we have chosen to be as transparent as possible and explain below why we find that, if finalized, the protections, prohibitions, and exceptions in this proposed rule as a whole satisfy the requirement in section 4(d) of the Act to issue regulations deemed necessary and advisable to provide for the conservation of the western regal fritillary.

The protective regulations we are proposing for the western regal fritillary incorporate prohibitions from section 9(a)(1) of the Act to address the threats to the subspecies. The prohibitions of section 9(a)(1) of the Act, and implementing regulations codified at 50 CFR 17.21, make it illegal for any person subject to the jurisdiction of the United States to commit, to attempt to commit, to solicit another to commit or to cause to be committed any of the following acts with regard to any endangered wildlife: (1) import into, or export from, the United States; (2) take (which includes harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect) within the United States, within the territorial sea of the United States, or on the high seas; (3) possess, sell, deliver, carry, transport, or ship, by any means whatsoever, any such wildlife that has been taken illegally; (4) deliver, receive, carry, transport, or ship in interstate or foreign commerce, by any means whatsoever and in the course of commercial activity; or (5) sell or offer for sale in interstate or foreign commerce. This protective regulation includes all of these prohibitions because the western regal fritillary is at risk of extinction within the foreseeable future and putting these prohibitions in place will help to conserve the subspecies' remaining populations, slow its rate of decline, and decrease synergistic, negative effects from other stressors.

In particular, this proposed 4(d) rule would provide for the conservation of the western regal fritillary by prohibiting the following activities, unless they fall within specific exceptions or are otherwise authorized or permitted: importing or exporting; take; possession and other acts with unlawfully taken specimens; delivering, receiving, carrying, transporting, or shipping in interstate or foreign commerce in the course of commercial activity; or selling or offering for sale in interstate or foreign commerce.

Under the Act, “take” means to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct. Some of these provisions have been further defined in regulations at 50 CFR 17.3. Take can result knowingly or otherwise, by direct and indirect impacts, intentionally or incidentally. Regulating take would help preserve the subspecies' remaining populations, slow their rate of decline, and decrease synergistic, negative effects from other stressors. Therefore, we propose to prohibit take of the western regal fritillary, except for take resulting from those actions and activities specifically excepted by the 4(d) rule.

Exceptions to the prohibition on take would include all of the general exceptions to the prohibition on take of endangered wildlife, as set forth in 50 CFR 17.21 and additional exceptions, as described below. Despite these prohibitions regarding threatened species, we may under certain circumstances issue permits to carry out one or more otherwise-prohibited activities, including those described above. The regulations that govern permits for threatened wildlife state that the Director may issue a permit authorizing any activity otherwise prohibited with regard to threatened species. These include permits issued for the following purposes: for scientific purposes, to enhance propagation or survival, for economic hardship, for zoological exhibition, for educational purposes, for incidental taking, or for special purposes consistent with the purposes of the Act (50 CFR 17.32). The statute also contains certain exemptions from the prohibitions, which are found in sections 9 and 10 of the Act.

In addition, to further the conservation of the species, any employee or agent of the Service, any other Federal land management agency, the National Marine Fisheries Service, a State conservation agency, or a federally recognized Tribe, who is designated by their agency or Tribe for such purposes, may, when acting in the course of their official duties, take threatened wildlife without a permit if such action is necessary to: (i) Aid a sick, injured, or orphaned specimen; or (ii) Dispose of a dead specimen; or (iii) Salvage a dead specimen that may be useful for scientific study; or (iv) Remove specimens that constitute a demonstrable but nonimmediate threat to human safety, provided that the taking is done in a humane manner; the taking may involve killing or injuring only if it has not been reasonably possible to eliminate such threat by live capturing and releasing the specimen unharmed, in an appropriate area.

We recognize the special and unique relationship that we have with our State natural resource agency partners in contributing to conservation of listed species. State agencies often possess scientific data and valuable expertise on the status and distribution of endangered, threatened, and candidate species of wildlife and plants. State agencies, because of their authorities and their close working relationships with local governments and landowners, are in a unique position to assist us in implementing all aspects of the Act. In this regard, section 6 of the Act provides that we must cooperate to the maximum extent practicable with the States in carrying out programs authorized by the Act. Therefore, any qualified employee or agent of a State conservation agency that is a party to a cooperative agreement with us in accordance with section 6(c) of the Act, who is designated by his or her agency for such purposes, would be able to conduct activities designed to conserve the western regal fritillary that may result in otherwise prohibited take without additional authorization.

The proposed 4(d) rule would also provide for the conservation of the western subspecies by excepting otherwise prohibited take associated with several activities either intended to incentivize conservation actions or that, while they may have some minimal level of take of the western regal fritillary, are not expected to rise to the level that would have a negative impact ( i.e., would have only de minimis impacts) on the western subspecies' conservation. We propose to except incidental take associated with routine livestock operations, livestock grazing, noxious weed control, annual haying and mowing, prescribed fire, brush control, and mowing section line rights-of-way and recreational trails; we describe each in more detail below. These activities are expected to have negligible impacts to the western regal fritillary and its habitat.

Incidental take caused by the routine livestock ranching activities that are described below and that are implemented on private, State, or Tribal lands or on other lands not under Federal jurisdiction ( e.g., lands owned by county or local governments) would not be prohibited, as long as those activities are otherwise legal and conducted in accordance with applicable State, Federal, Tribal, and local laws and regulations. For the purposes of this proposed 4(d) rule, routine livestock ranching activities include (as described below) the construction and maintenance of fences, the gathering and management of livestock, and the development and maintenance of watering facilities for livestock.

Fences are an essential tool for livestock and ranch management. In addition, the strategic distribution of fencing is also necessary to implement multicell rotational grazing systems, which may be necessary to improve grazing management and provide a conservation benefit to the western regal fritillary's habitat. Therefore, incidental take associated with the construction and maintenance of fencing to manage livestock and ranches will be excepted.

The installation and maintenance of corrals, loading chutes, and other livestock working facilities are critical to ranch operations. These activities may be carried out with only minimal impacts to the western regal fritillary. Therefore, incidental take associated with livestock gathering and management activities will be excepted.

Without a suitable water source in a pasture, livestock ranching is impossible. The proper distribution of livestock watering sources is also a prerequisite to implementing improved grazing management via the use of multicell rotational grazing systems that may be necessary to conserve western regal fritillary habitat and to provide a conservation benefit to the subspecies on grazed sites. This activity includes both the initial development of water sources and their maintenance. Dugout ponds, for example, typically require a cleanout after 15 to 20 years.

Incidental take of the western regal fritillary that may result from livestock grazing on private, State, or Tribal land would be excepted from the take prohibitions of section 9 of the Act. By excepting take of the western regal fritillary caused by livestock grazing, we acknowledge the positive role that some ranchers have played in conserving the western regal fritillary and that grazing can be compatible with maintaining remaining native grasslands. Grazing and browsing by livestock may improve and maintain regal fritillary habitat by removing herbaceous vegetation that shades and competes with violets and results in earlier successional stages within the grasslands, contributing to the landscape-level mosaic of habitats used by the western regal fritillary. Best management practices to make grazing compatible with regal fritillary conservation may include light-to-moderate grazing intensities in the late fall and early spring, patch burn grazing methods to maintain a shifting mosaic of habitats and prevent woodland encroachment, and avoiding the broadcast spraying of herbicides across large areas to kill plants that compete with grasses. Recovery of the western regal fritillary will depend on the protection and restoration of high-quality habitats supporting violets and nectar sources on private lands and on public lands that are grazed by private individuals under lease or other agreements. Therefore, incidental take associated with livestock grazing on private, State, or Tribal lands, including light-to-moderate grazing intensities in the late fall and early spring, and patch burn grazing methods that may help maintain an annually shifting mosaic of fire and grazing across a landscape to increase the diversity and structure of vegetation will be excepted.

State and county laws require landowners to control noxious weeds on their property, and the timing of control actions is usually dependent on the growth stage of the weed species. Control of noxious weeds may also be important to protecting western regal fritillary habitat because native plant diversity declines when nonnative plant species invade and become established in prairies (Boettcher et al. 1993, p. 35). Spot spraying, hand pulling, or mechanical treatment of noxious weeds would be excepted from the take prohibitions and may occur at any time during the year. Incidental take that occurs as a result of mowing that is carried out for the purpose of controlling one or more noxious weed species will also be excepted.

Broadcast application of herbicides, however, may result in significant deterioration of native plant diversity in prairies (Smart et al. 2011, p. 184). Therefore, we would not except incidental take of the western regal fritillary that may result from broadcast spraying of herbicides, which we define as the application of herbicides, often aerially or by vehicles, evenly, widely, and indiscriminately across the entire application area, unless the application area is dominated by noxious weeds.

Haying and mowing of native grasslands can improve western regal fritillary habitats by removing vegetation that outcompetes violets for light, nutrients, and water; stimulating the growth of native nectar sources; and improving the mosaic of diverse successional stages. Therefore, we will except incidental take associated with annual haying and mowing in western regal fritillary habitats.

Prescribed fire is a key grassland management tool that can preserve native grassland habitat by controlling woody encroachment and introduced species and stimulating growth of native vegetation. When used with other grassland management techniques and best management practices, the periodic disturbance caused by prescribed fire helps maintain suitable regal fritillary habitat on the landscape. We acknowledge that fire is also a stressor to the western subspecies. Adverse effects to individuals may occur if burning occurs in occupied habitats, and local population-level impacts are possible if suitable occupied habitats are burned extensively without retaining refugia or if such sites are lacking adjacent proximal occupied habitats that could serve as recolonization sources. However, these effects can be controlled to maximize the benefits to the western regal fritillary. Therefore, we will except incidental take associated with prescribed fire if the following conditions are met to reduce adverse effects:

(a) Prescribed fire burn units must be established to avoid burning the majority of suitable habitat at the landscape scale and to allow for refugia; and

(b) The return interval for prescribed fire on a particular unit is 3 to 5 years.

If allowed to become too dense, woody vegetation can crowd out native grassland habitat. Consequently, brush control would be excepted from the take prohibitions and may occur at any time during the year. Brush control methods may include mechanical means, burning, grazing, or spot use of herbicides if in compliance with the other excepted activities in the 4(d) rule. If mechanical means such as brush hogs are used, the blade must be set to 20 cm (8 in) or higher above the ground. If herbicides are used, an appropriate systemic herbicide to prevent regrowth must be directly applied to cut stems. Broadcast spraying in western regal fritillary habitat would not be excepted because it may remove all violet and nectar plants for the western subspecies.

Section line rights-of-way and some recreational trails need to be mowed several times during the growing season to ensure that snow will not catch and block vehicle access and to ensure access and safety for hiking and other intended recreational activities, respectively. Section line rights-of-way typically have disturbed soil that has been contoured for a roadway and are likely to contain only small proportions of western regal fritillary habitat at any affected site. Recreational trails are travel ways established either through construction or use that are intended for and passable by at least one or more of the following: foot traffic, bicycles, in-line skates, wheelchairs, or cross-country skis. Such trails are typically narrower than roads. Therefore, impacts to western regal fritillary individuals and populations are likely to be minimal, and any incidental take that results from mowing section line rights-of-way and recreational trails will be excepted.

Critical habitat is defined in section 3 of the Act as:

(1) The specific areas within the geographical area occupied by the species, at the time it is listed in accordance with the Act, on which are found those physical or biological features

(a) Essential to the conservation of the species, and

(b) Which may require special management considerations or protection; and

(2) Specific areas outside the geographical area occupied by the species at the time it is listed, upon a determination that such areas are essential for the conservation of the species.

Our regulations at 50 CFR 424.02 define the geographical area occupied by the species as an area that may generally be delineated around species' occurrences, as determined by the Secretary ( i.e., range). Such areas may include those areas used throughout all or part of the species' life cycle, even if not used on a regular basis ( e.g., migratory corridors, seasonal habitats, and habitats used periodically, but not solely by vagrant individuals).

Conservation, as defined under section 3 of the Act, means to use and the use of all methods and procedures that are necessary to bring an endangered or threatened species to the point at which the measures provided pursuant to the Act are no longer necessary. Such methods and procedures include, but are not limited to, all activities associated with scientific resources management such as research, census, law enforcement, habitat acquisition and maintenance, propagation, live trapping, and transplantation, and, in the extraordinary case where population pressures within a given ecosystem cannot be otherwise relieved, may include regulated taking.

Critical habitat receives protection under section 7 of the Act through the requirement that each Federal action agency ensure, in consultation with the Service, that any action they authorize, fund, or carry out is not likely to result in the destruction or adverse modification of designated critical habitat. The designation of critical habitat does not affect land ownership or establish a refuge, wilderness, reserve, preserve, or other conservation area. Such designation also does not allow the government or public to access private lands. Such designation does not require implementation of restoration, recovery, or enhancement measures by non-Federal landowners. Rather, designation requires that, where a landowner requests Federal agency funding or authorization for an action that may affect an area designated as critical habitat, the Federal agency consult with the Service under section 7(a)(2) of the Act. If the action may affect the listed species itself (such as for occupied critical habitat), the Federal agency would have already been required to consult with the Service even absent the designation because of the requirement to ensure that the action is not likely to jeopardize the continued existence of the species. Even if the Service were to conclude after consultation that the proposed activity is likely to result in destruction or adverse modification of the critical habitat, the Federal action agency and the landowner are not required to abandon the proposed activity, or to restore or recover the species; instead, they must implement “reasonable and prudent alternatives” to avoid destruction or adverse modification of critical habitat.

Under the first prong of the Act's definition of critical habitat, areas within the geographical area occupied by the species at the time it was listed are included in a critical habitat designation if they contain physical or biological features (1) which are essential to the conservation of the species and (2) which may require special management considerations or protection. For these areas, critical habitat designations identify, to the extent known using the best scientific data available, those physical or biological features that are essential to the conservation of the species (such as space, food, cover, and protected habitat).

Under the second prong of the Act's definition of critical habitat, we can designate critical habitat in areas outside the geographical area occupied by the species at the time it is listed, upon a determination that such areas are essential for the conservation of the species.

Section 4 of the Act requires that we designate critical habitat on the basis of the best scientific data available. Further, our Policy on Information Standards Under the Endangered Species Act (published in the Federal Register on July 1, 1994 (59 FR 34271)), the Information Quality Act (section 515 of the Treasury and General Government Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658)), and our associated Information Quality Guidelines provide criteria, establish procedures, and provide guidance to ensure that our decisions are based on the best scientific data available. They require our biologists, to the extent consistent with the Act and with the use of the best scientific data available, to use primary and original sources of information as the basis for recommendations to designate critical habitat.

When we are determining which areas should be designated as critical habitat, our primary source of information is generally the information from the SSA report and information developed during the listing process for the species. Additional information sources may include any generalized conservation strategy, criteria, or outline that may have been developed for the species; the recovery plan for the species; articles in peer-reviewed journals; conservation plans developed by States and counties; scientific status surveys and studies; biological assessments; other unpublished materials; or experts' opinions or personal knowledge.

Habitat is dynamic, and species may move from one area to another over time. We recognize that critical habitat designated at a particular point in time may not include all of the habitat areas that we may later determine are necessary for the recovery of the species. For these reasons, a critical habitat designation does not signal that habitat outside the designated area is unimportant or may not be needed for recovery of the species. Areas that are important to the conservation of the species, both inside and outside the critical habitat designation, will continue to be subject to: (1) Conservation actions implemented under section 7(a)(1) of the Act; (2) regulatory protections afforded by the requirement in section 7(a)(2) of the Act for Federal agencies to ensure their actions are not likely to jeopardize the continued existence of any endangered or threatened species; and (3) the prohibitions found in section 9 of the Act for the eastern subspecies or the 4(d) rule for the western subspecies. Federally funded or permitted projects affecting listed species outside their designated critical habitat areas may still result in jeopardy findings in some cases. These protections and conservation tools will continue to contribute to recovery of the species. Similarly, critical habitat designations made on the basis of the best available information at the time of designation will not control the direction and substance of future recovery plans, habitat conservation plans, or other species conservation planning efforts if new information available at the time of those planning efforts calls for a different outcome.

We have determined that critical habitat is prudent, but not presently determinable, for both the eastern and western subspecies of regal fritillary. Our regulations at 50 CFR 424.12(a)(2) state that critical habitat is not determinable when one or both of the following situations exist:

(i) Data sufficient to perform required analyses are lacking, or

(ii) The biological needs of the species are not sufficiently well known to identify any area that meets the definition of “critical habitat.”

When critical habitat is not determinable, the Act allows the Service an additional year to publish a critical habitat designation (16 U.S.C. 1533(b)(6)(C)(ii)).

We have reviewed the available information pertaining to the biological needs of the regal fritillary and habitat characteristics where each subspecies is located. Careful assessments of the economic and environmental impacts that may occur due to a critical habitat designation are not yet complete, and we are working to acquire the complex information needed to perform those assessments. At this time, the information needed to perform the required analysis of the impacts of the designation is lacking for both subspecies. Therefore, we conclude that the designation of critical habitat for both the eastern and western subspecies of regal fritillary is not determinable at this time. The Act allows the Service an additional year to publish a critical habitat designation that is not determinable at the time of listing (16 U.S.C. 1533(b)(6)(C)(ii)).

We are required by E.O.s 12866 and 12988 and by the Presidential Memorandum of June 1, 1998, to write all rules in plain language. This means that each rule we publish must:

(1) Be logically organized;

(2) Use the active voice to address readers directly;

(3) Use clear language rather than jargon;

(4) Be divided into short sections and sentences; and

(5) Use lists and tables wherever possible.

If you feel that we have not met these requirements, send us comments by one of the methods listed in ADDRESSES . To better help us revise the rule, your comments should be as specific as possible. For example, you should tell us the numbers of the sections or paragraphs that are unclearly written, which sections or sentences are too long, the sections where you feel lists or tables would be useful, etc.

Regulations adopted pursuant to section 4(a) of the Act are exempt from the National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq. ) and do not require an environmental analysis under NEPA. We published a notice outlining our reasons for this determination in the Federal Register on October 25, 1983 (48 FR 49244). This includes listing, delisting, and reclassification rules, as well as critical habitat designations and species-specific protective regulations promulgated concurrently with a decision to list or reclassify a species as threatened. The courts have upheld this position ( e.g., Douglas County v. Babbitt, 48 F.3d 1495 (9th Cir. 1995) (critical habitat); Center for Biological Diversity v. U.S. Fish and Wildlife Service, 2005 WL 2000928 (N.D. Cal. Aug. 19, 2005) (concurrent 4(d) rule)).

In accordance with the President's memorandum of April 29, 1994 (Government-to-Government Relations with Native American Tribal Governments; 59 FR 22951), E.O. 13175 (Consultation and Coordination with Indian Tribal Governments), and the Department of the Interior's manual at 512 DM 2, we readily acknowledge our responsibility to communicate meaningfully with federally recognized Tribes on a government-to-government basis. In accordance with Secretaries' Order 3206 of June 5, 1997 (American Indian Tribal Rights, Federal-Tribal Trust Responsibilities, and the Endangered Species Act), we readily acknowledge our responsibilities to work directly with Tribes in developing programs for healthy ecosystems, to acknowledge that Tribal lands are not subject to the same controls as Federal public lands, to remain sensitive to Indian culture, and to make information available to Tribes. The eastern subspecies does not occur on Tribal lands. For the western subspecies, we solicited information from the Tribes within the subspecies' range to inform the development of our SSA report, but we did not receive any responses. We will continue to coordinate with affected Tribes throughout the listing process, as appropriate.

A complete list of references cited in this rulemaking is available on the internet at https://www.regulations.gov and upon request from the South Dakota Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT ).

The primary authors of this proposed rule are the staff members of the U.S. Fish and Wildlife Service's Species Assessment Team and the South Dakota and Pennsylvania Ecological Services Field Offices.

Accordingly, we propose to amend part 17, subchapter B of chapter I, title 50 of the Code of Federal Regulations, as set forth below: