Interested parties are invited to participate in this proposed rulemaking by submitting such written data, views, or arguments as they may desire. Comments that provide the factual basis supporting the views and suggestions presented are particularly helpful in developing reasoned regulatory decisions on the proposal. Comments are specifically invited on the overall regulatory, aeronautical, economic, environmental, and energy-related aspects of the proposal.

Communications should identify both docket numbers (FAA Docket No. FAA-2013-0960 and Airspace Docket No. 13-AGL-17) and be submitted in triplicate to the Docket Management Facility (see ADDRESSES section for address and phone number). You may also submit comments through the Internet at http://www.regulations.gov.

Commenters wishing the FAA to acknowledge receipt of their comments on this action must submit with those comments a self-addressed, stamped postcard on which the following statement is made: “Comments to FAA Docket No. FAA-2013-0930 and Airspace Docket No. 13-AGL-17.” The postcard will be date/time stamped and returned to the commenter.

All communications received on or before the specified comment closing date will be considered before taking action on the proposed rule. The proposal contained in this action may be changed in light of comments received. All comments submitted will be available for examination in the public docket both before and after the comment closing date. A report summarizing each substantive public contact with FAA personnel concerned with this rulemaking will be filed in the docket.

An electronic copy of this document may be downloaded through the Internet at http://www.regulations.gov.

You may review the public docket containing the proposal, any comments received and any final disposition in person in the Dockets Office (see ADDRESSES section for address and phone number) between 9:00 a.m. and 5:00 p.m., Monday through Friday, except Federal holidays. An informal docket may also be examined during normal business hours at the office of the Central Service Center, Operations Support Group, Federal Aviation Administration, 2601 Meacham Blvd., Fort Worth, TX 76137.

Persons interested in being placed on a mailing list for future NPRMs should contact the FAA's Office of Rulemaking, (202) 267-9677, for a copy of Advisory Circular No. 11-2A, Notice of Proposed Rulemaking Distribution System, which describes the application procedure.

The Peck, MI (ECK), VOR is being decommissioned due to signal interference impacts to the facility created by a power line project that is being constructed in the proximity of the ECK VOR; however, the collocated TACAN facility will remain in service. The power line project is a State of Michigan initiative to provide renewable energy to the State by 2015 with a plan to construct power line towers and route transmission lines within 1,400 feet of the ECK VOR facility. Modeling impacts of the proposed power line construction project on the ECK VOR determined that the project will cause bearing errors in excess of flight check tolerances at multiple azimuths around the facility, thereby compromising the integrity of the existing airways supported by the ECK VOR. A determination has been made to permanently decommission the facility due to the projected signal degradation from the planned power line nearby. Additionally, the ECK VOR is not on the list of VORs planned for retention in the VOR Minimum Operational Network (MON). As a result, the ATS routes that utilize the ECK VOR must be amended.

The affected routes are: jet route J-16, J-38, J-94, J-546, J-551, and J-553, and VOR Federal airways V-84, V-216, V-320, and V-337. With the decommissioning of the ECK VOR, ground-based navigation aid (NAVAID) coverage is insufficient to enable the continuity of all the airways. Therefore, the proposed modifications to jet routes J-16 and J-94, and VOR Federal airways V-84 and V-337 would result in a gap in the route structures. To overcome the gaps created in the route structures, air traffic control (ATC) would either provide radar vectoring or reroute affected aircraft using the remaining route structure, as determined appropriate.

This action also proposes to modify V-216 further by removing the route segment that is charted unusable from the Janesville, WI (JVL), VOR to the Muskegon, MI (MKG), VHF Omnidirectional Range/Tactical Air Navigation (VORTAC) facility, as well as removing the route segment from MKG to the Saginaw, MI (MBS), VOR due to low usage and large portions of V-216 to the west and east being removed. The route segment from JVL to MKG has been unusable since 2009 as a result of the MKG radial supporting V-216 failing flight inspection and the FAA being unable to resolve the associated MKG VOR radial restrictions. The route segment from MKG to MBS is also proposed to be removed due to its limited use (less than six aircraft per day, on average), and being bracketed by substantial airway segments to the west and east being removed. As mentioned previously, ATC would either provide radar vectoring or reroute affected aircraft using remaining route structure to overcome this gap in V-216.

The FAA is proposing an amendment to Title 14, Code of Federal Regulations (14 CFR) part 71 to amend jet routes J-16, J-38, and J-94, and VOR Federal airways V-84, V-216, V-320, and V-337. The FAA also proposes to remove jet routes J-546, J-551, and J-553. The scheduled decommissioning of the ECK VOR facility has made this action necessary. The proposed route changes are outlined below.

J-16: J-16 currently extends between Battle Ground, WA (BTG) and Boston, MA (BOS), excluding the airspace within Canada. The FAA would eliminate the part of the route between Badger, WI (BAE) and London, ON, Canada (YXU). The unaffected portions of the existing route will remain as charted in the two remaining segments.

J-38: J-38 currently extends between Duluth, MN (DLH) and Peck, MI (ECK). The FAA would eliminate the part of the route between Green Bay, WI (GRB) and ECK. The unaffected portion of the existing route will remain as charted.

J-94: J-94 currently extends between Oakland, CA (OAK) and Boston, MA (BOS), excluding the airspace within Canada. The FAA would eliminate the part of the route between Flint, MI (FNT) and London, ON, Canada (YXU). The unaffected portions of the existing route will remain as charted in the two remaining segments.

V-84: V-84 currently extends between Northbrook, IL (OBK) and Syracuse, NY (SYR), excluding the airspace within Canada. The FAA would eliminate the part of the route between Flint, MI (FNT) and London, ON, Canada (YXU). The unaffected portions of the existing route will remain as charted in the two remaining segments.

V-216: V-216 currently extends between Lamar, CO (LAA) and Toronto, ON, Canada (YYZ), excluding the airspace within Canada. The FAA would eliminate the part of the route between Janesville, WI (JVL) and YYZ. The unaffected portions of the existing route will remain as charted in the two remaining segments.

V-320: V-320 currently extends between Pellston, MI (PLN) and Toronto, ON, Canada (YYZ), excluding the airspace within Canada. The FAA would eliminate the part of the route between Saginaw, MI (MBS) and YYZ. The unaffected portions of the existing route will remain as charted in the two remaining segments.

V-337: V-337 currently extends between the intersection of the Briggs, OH (BSV), 077° and Youngstown, OH (YNG), 177° radials and White Cloud, MI (HIC). The FAA would eliminate the part of the route between Akron, OH (ACO) Saginaw, MI (MBS). The unaffected portions of the existing route will remain as charted in the two remaining segments.

The navigation aid radials cited in the proposed route descriptions, below, are unchanged from the existing routes and stated relative to True north.

Jet routes are published in paragraph 2004 and VOR Federal airways are published in paragraph 6010(a), respectively, of FAA Order 7400.9X dated August 7, 2013, and effective September 15, 2013, which is incorporated by reference in 14 CFR 71.1. The jet routes and VOR Federal airways listed in this document would be subsequently published in the Order.

The FAA has determined that this proposed regulation only involves an established body of technical regulations for which frequent and routine amendments are necessary to keep them operationally current. Therefore, this proposed regulation: (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under Department of Transportation (DOT) Regulatory Policies and Procedures (44 FR 11034; February 26, 1979); and (3) does not warrant preparation of a regulatory evaluation as the anticipated impact is so minimal. Since this is a routine matter that would only affect air traffic procedures and air navigation, it is certified that this proposed rule, when promulgated, will not have a significant economic impact on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

The FAA's authority to issue rules regarding aviation safety is found in Title 49 of the United States Code. Subtitle I, Section 106 describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the agency's authority.

This rulemaking is promulgated under the authority described in Subtitle VII, Part A, Subpart I, Section 40103. Under that section, the FAA is charged with prescribing regulations to assign the use of the airspace necessary to ensure the safety of aircraft and the efficient use of airspace. This regulation is within the scope of that authority as it would modify the route structure as necessary to preserve the safe and efficient flow of air traffic within the NAS.

This proposal will be subject to an environmental analysis in accordance with FAA Order 1050.1E, “Environmental Impacts: Policies and Procedures” prior to any FAA final regulatory action.

In consideration of the foregoing, the Federal Aviation Administration proposes to amend 14 CFR part 71 as follows:

Posting of Public Comments

Please note that all comments received in response to this docket are considered part of the public record and will be made available for public inspection online at www.regulations.gov . Such information includes personal identifying information (such as your name, address, etc.) voluntarily submitted by the commenter.

If you want to submit personal identifying information (such as your name, address, etc.) as part of your comment, but do not want it to be made publicly available, you must include the phrase “PERSONAL IDENTIFYING INFORMATION” in the first paragraph of your comment. You must also place all of the personal identifying information you do not want made publicly available in the first paragraph of your comment and identify what information you want redacted.

If you want to submit confidential business information as part of your comment, but do not want it to be made publicly available, you must include the phrase “CONFIDENTIAL BUSINESS INFORMATION” in the first paragraph of your comment. You must also prominently identify the confidential business information to be redacted within the comment. If a comment has so much confidential business information that it cannot be effectively redacted, all or part of that comment may not be made publicly available. Comments containing personal identifying information or confidential business information identified as directed above will be made publicly available in redacted form.

The Freedom of Information Act (FOIA) applies to all comments received. If you wish to personally inspect the comments and materials received or the supporting documentation the DEA used in preparing the proposed action, these materials will be available for public inspection by appointment. To arrange a viewing, please see the For Further Information Contact paragraph above.

Pursuant to the provisions of the CSA, 21 U.S.C. 811(a), this action is a formal rulemaking “on the record after opportunity for a hearing.” Such proceedings are conducted pursuant to the provisions of the Administrative Procedure Act (APA), 5 U.S.C. 551-559. 21 CFR 1308.41-1308.45; 21 CFR part 1316 subpart D. In accordance with 21 CFR 1308.44(a)-(c), requests for a hearing, notices of appearance, and waivers of an opportunity for a hearing or to participate in a hearing may be submitted only by interested persons, defined as those “adversely affected or aggrieved by any rule or proposed rule issuable pursuant to section 201 of the Act (21 U.S.C. 811).” 21 CFR 1300.01. Requests for hearing and notices of appearance must conform to the requirements of 21 CFR 1308.44(a) or (b), and 1316.47 or 1316.48 as applicable, and include a statement of the interest of the person in the proceeding and the objections or issues, if any, concerning which the person desires to be heard. Any waiver must conform to the requirements of 21 CFR 1308.44(c) and 1316.49, including a written statement regarding the interested person's position on the matters of fact and law involved in any hearing.

Please note that pursuant to 21 U.S.C. 811(a), the purpose and subject matter of a hearing held in relation to this rulemaking is restricted to: “(A) find[ing] that such drug or other substance has a potential for abuse, and (B) mak[ing] with respect to such drug or other substance the findings prescribed by subsection (b) of section 812 of [Title 21] for the schedule in which such drug is to be placed. . . .” Requests for a hearing, notices of appearance at a hearing, and waivers of an opportunity for a hearing or to participate in a hearing must be submitted to the DEA using the address information provided above.

The DEA implements and enforces titles II and III of the Comprehensive Drug Abuse Prevention and Control Act of 1970, as amended. Titles II and III are referred to as the “Controlled Substances Act” and the “Controlled Substances Import and Export Act,” respectively, and are collectively referred to as the “Controlled Substances Act” or the “CSA” for the purpose of this action. 21 U.S.C. 801-971. The DEA publishes the implementing regulations for these statutes in title 21 of the Code of Federal Regulations (CFR), parts 1300 to 1321. The CSA and its implementing regulations are designed to prevent, detect, and eliminate the diversion of controlled substances and listed chemicals into the illicit market while providing for the legitimate medical, scientific, research, and industrial needs of the United States. Controlled substances have the potential for abuse and dependence and are controlled to protect the public health and safety.

Under the CSA, controlled substances are classified into one of five schedules based upon their potential for abuse, their currently accepted medical use, and the degree of dependence the substance may cause. 21 U.S.C. 812. The initial schedules of controlled substances established by Congress are found at 21 U.S.C. 812(c), and the current list of all scheduled substances is published at 21 CFR part 1308.

Pursuant to 21 U.S.C. 811(a)(1), the Attorney General may, by rule, “add to such a schedule or transfer between such schedules any drug or other substance if he (A) finds that such drug or other substance has a potential for abuse, and (B) makes with respect to such drug or other substance the findings prescribed by [21 U.S.C. 812(b)] for the schedule in which such drug is to be placed. . . .” Pursuant to 28 CFR 0.100(b), the Attorney General has delegated this scheduling authority to the Administrator of the DEA who has further delegated this authority to the Deputy Administrator of the DEA under 28 CFR 0.104.

The CSA provides that scheduling of any drug or other substance may be initiated by the Attorney General (1) on his own motion; (2) at the request of the Secretary of Health and Human Services (HHS); or (3) on the petition of any interested party. 21 U.S.C. 811(a). If finalized, this action would impose the regulatory controls and administrative, civil, and criminal sanctions of schedule IV controlled substances for any person who handles suvorexant.

Suvorexant ([(7 R )-4-(5-chloro-1,3-benzoxazol-2-yl)-7-methyl-1,4-diazepan-1-yl][5-methyl-2-(2 H -1,2,3-triazol-2-yl)phenyl]methanone), also known as MK-4305, is a new chemical entity developed for the treatment of insomnia. Suvorexant is a novel, first in class, orexin receptor antagonist with a mechanism of action distinct from any marketed drug. It acts via inhibition of the orexin 1 (OX1) and orexin 2 (OX2) receptors. In pharmacological activity studies, suvorexant functioned as an antagonist as demonstrated by its ability to block agonist-induced calcium (Ca 2+ ) release.

Pursuant to 21 U.S.C. 811(a), proceedings to add a drug or substance to those controlled under the CSA may be initiated by request of the Secretary of the HHS. 1 On June 27, 2013, the HHS provided the DEA with a scientific and medical evaluation document prepared by the FDA entitled “Basis for the Recommendation to Place Suvorexant in Schedule IV of the Controlled Substances Act.” Pursuant to 21 U.S.C. 811(b), this document contained an eight-factor analysis of the abuse potential of suvorexant as a new drug, along with the HHS' recommendation to control suvorexant under schedule IV of the CSA.

In response, the DEA reviewed the scientific and medical evaluation and scheduling recommendation provided by the HHS, and all other relevant data, and completed its own eight-factor review document pursuant to 21 U.S.C. 811(c). Included below is a brief summary of each factor as analyzed by the HHS and the DEA, and as considered by the DEA in its proposed scheduling action. Please note that both the DEA and HHS analyses are available in their entirety under “Supporting and Related Material” in the public docket for this proposed rule at www.regulations.gov , under Docket Number “DEA-381.” Full analysis of, and citations to, the information referenced in the summary may also be found in the supporting and related material.

1. The Drug's Actual or Relative Potential for Abuse: Suvorexant is a new chemical entity that has not been marketed in the United States or any other country. As such, there is no information available detailing actual abuse of suvorexant. However, the legislative history of the CSA offers the following criterion for assessing a new drug or substance's potential for abuse:

As described further below, there is strong evidence that suvorexant produces behavioral effects in humans and in animals that are similar to those produced by zolpidem (schedule IV).

With a mechanism of action that is distinct from any other marketed drug, including those marketed for insomnia (i.e., schedule IV benzodiazepines, and non-benzodiazepine hypnotics such as zolpidem (schedule IV), eszopiclone  3 (schedule IV), and zaleplon (schedule IV)), suvorexant acts as an antagonist at the OX1 and OX2 receptors and produces sedative and sleep promoting effects in humans.

In a human abuse potential study in subjects with histories of recreational sedative use, suvorexant produced reinforcing subjective effects similar to zolpidem (schedule IV). Doses of 40, 80, and 150 mg of suvorexant were compared to 15 and 30 mg doses of zolpidem (schedule IV). On the visual analog scale (VAS), suvorexant produced “ `at the moment' Drug Liking” and “High and Good,” effects statistically indistinguishable from zolpidem (schedule IV). Suvorexant also produced effects similar to zolpidem (schedule IV) in “Overall Drug Liking,” “Take Drug Again,” “Any Drug Effect,” assessments of subjective drug value, and overall familiarity measures. Additionally, on the Bowdle VAS (a measure of perceptual and hallucinogenic effects) suvorexant produced effects statistically similar to zolpidem (schedule IV). Suvorexant produced less dysphoria and adverse effects than zolpidem (schedule IV), suggesting that suvorexant may have an increased abuse potential relative to zolpidem (schedule IV). Measures to evaluate cognitive and psychomotor impairment (e.g., reaction time, attention, and vigilance) showed that suvorexant produced levels of impairment that were similar to the low dose (15 mg) of zolpidem (schedule IV). These data suggest that zolpidem (schedule IV) and suvorexant present a similar risk to the public health, and that suvorexant impairs cognition at both therapeutic (e.g., 40 mg) and supratherapeutic doses. As the dose of suvorexant increased, there was no increase in drug effects. This fact is especially important because the lowest dose of suvorexant examined in the human abuse potential study (40 mg) is the maximum planned therapeutic dose—suggesting that therapeutic doses of suvorexant (e.g., 40 mg) will have significant abuse liability and produce cognitive and psychomotor impairment.

These data suggest that suvorexant and zolpidem (schedule IV) have a similar abuse potential. The similarities between suvorexant and zolpidem (schedule IV) indicate that there will be significant diversion of these substances from legitimate channels, and significant use contrary to or without medical advice. In addition, as discussed in Factor 3, the long half-life of suvorexant may be a critical factor in the drug's safety profile as suvorexant's duration of action may create significant hazards to the health of the user or to the safety of the community, and result in “next day” effects in patients.

2. Scientific Evidence of the Drug's Pharmacological Effects, if Known: The orexin signaling system was discovered in 1998 and has been implicated in numerous physiological functions involving the central nervous system (CNS) such as sleep and wakefulness, appetite/metabolism, stress response, reward/addiction, and analgesia. Orexin A and orexin B are peptide neurotransmitters produced through cleavage of a preprohormone. These neurotransmitters bind with a high degree of selectivity to two different G-protein coupled receptors (GPCR's), namely OX1 and OX2. These orexin receptors are broadly expressed in cortical, thalamic, and hypothalamic neuronal circuits. Suvorexant blocks the wakefulness promoting effects of the orexins, facilitating the sleep process. In pharmacological studies, suvorexant functioned as an antagonist as demonstrated by its ability to block agonist-induced calcium (Ca 2+ ) release.

In receptor binding studies to determine the binding affinity as assessed by the ability of suvorexant to displace a reference compound (expressed as K i value), suvorexant produced K i values of 0.55 nM and 0.35 nM for the OX1 and OX2 receptors, indicating a high affinity for these receptor subtypes. In in vitro functional studies, suvorexant blocked the effects of orexin receptor agonist in cells expressing OX1 and OX2 receptors. The concentrations of suvorexant inhibiting 50 percent of response (known as IC 50 ) were 49.9 nM at the OX1 receptors and 54.8 nM at OX2 receptors.

Like zolpidem, suvorexant (10, 20, 30 and 60 mg/kg) dose dependently reduced locomotor activity in rats, an expected characteristic of a sedative drug. Although rhesus monkeys trained to self-administer methohexital (schedule IV) did not self-administer suvorexant, the predictive validity of self-administration studies in evaluating the abuse potential of drugs acting via orexin receptors is unknown.

A human abuse potential study was performed to assess the abuse potential of suvorexant in human participants. The study demonstrated that suvorexant and zolpidem (schedule IV) produce similar reinforcing effects and have a similar potential for abuse in recreational drug users. Results showed that suvorexant produced effects statistically indistinguishable from zolpidem (schedule IV) in primary and secondary outcome measures. There was no increase in drug effects as the dose of suvorexant increased. This is an important observation, as the low dose of suvorexant (40 mg) in the human abuse potential study is the maximum proposed therapeutic dose. These data suggest that the maximum therapeutic dose of suvorexant (40 mg) was shown to produce cognitive and psychomotor impairment and will have a significant liability for abuse.

Results from another study measuring the effects of suvorexant (10, 50, and 100 mg) on sleep parameters and next-day residual effects demonstrated that the mid and high doses of suvorexant (50 and 100 mg) produced effects on next-day assessments of psychomotor performance and subjective effects. These results may be clinically relevant as the residual effects may be present in the morning following an evening administration (10 hours post-dose).

3. The State of Current Scientific Knowledge Regarding the Drug or Other Substance: The chemical name for suvorexant is [(7 R )-4-(5-chloro-1,3-benzoxazol-2-yl)-7-methyl-1,4-diazepan-1-yl][5-methyl-2-(2 H -1,2,3-triazol-2-yl)phenyl]methanone. It is a white to off-white powder. Other chemical names include: 1) Methanone, [(7 R )-4-(5-chloro-2-benzoxazolyl)hexahydro-7-methyl-1 H -1,4-diazepin-1-yl][5-methyl-2-(2 H -1,2,3-triazol-2-yl)phenyl]-; 2) [(7 R )-4-(5-chlorobenzoxazol-2-yl)-7-methylhexahydro-1 H -1,4-diazepin-1-yl][5-methyl-2-(2 H -1,2,3-triazol-2-yl)phenyl]methanone; 3) MK-4305; and 4) DORA-22. The Chemical Abstract Services number (CAS #) of suvorexant is: 1030377-33-3. At 25 °C, suvorexant is insoluble in water, soluble in methanol, very slightly soluble in heptane, and soluble in isopropyl acetate. The pH of a saturated aqueous solution of suvorexant was 8.6. Suvorexant has a molecular formula of C 23 H 23 ClN 6 O 2 and a molecular weight of 450.921 g. Suvorexant has a distinct chemical structure that is different from that of other sedative hypnotics such as the benzodiazepines (schedule IV).

There are several metabolites of suvorexant, although none appear to contribute significantly to its pharmacodynamic effects or abuse potential. Eight metabolites were detected in the plasma of healthy males administered radiolabeled suvorexant, with two of the metabolites present at concentrations great than 10 percent (M9 and M12). After oral administration of 15-40-mg, peak plasma concentrations (i.e., T max ) of suvorexant occurred at approximately 1-2 hours (range 0.5-6.0 hours), although the study authors noted slight variability based on the time of day. The terminal half-life of suvorexant is approximately 8-11 hours after a 40-mg dose. The pharmacokinetics of suvorexant following multiple dose administrations were similar to those following single dose administrations, with slightly less than dose proportional pharmacokinetics over 10-80 mg as assessed by AUC 0-∞ and C max . Steady state exposure was reached after 2-3 days of consecutive dosing.

4. Its History and Current Pattern of Abuse: Suvorexant is not currently marketed or available for sale in any country, therefore there is no known history or pattern of abuse. However, results from the human abuse potential study suggest that suvorexant produces effects that are similar to zolpidem (schedule IV) and would have a similar pattern of abuse.

5. The Scope, Duration, and Significance of Abuse: While the current scope, duration, and significance of abuse of suvorexant are unknown due to its non-marketed status, the results of the human abuse potential study previously described suggest that, upon marketing, the scope, duration, and significance of suvorexant abuse may be similar to zolpidem (schedule IV). Data from the Drug Abuse Warning Network (DAWN) and the Adverse Event Reporting System (AERS) demonstrate the scope, duration, and significance of abuse of zolpidem (schedule IV) and related sedative-like drugs. In general, emergency department (ED) visits reported for zolpidem (schedule IV) along with those specifically categorized as “misuse/abuse” have increased every year from 2004 to 2010, with a modest decrease reported for 2011. ED visits related to benzodiazepine sedatives including diazepam (schedule IV) and lorazepam (schedule IV) demonstrated a similar trend. Suvorexant would be expected to have a similar scope, duration, and significance of abuse.

6. What, If Any, Risk There Is to the Public Health: Suvorexant has a long terminal half-life of approximately 8-11 hours, which may increase the duration of its sedative effects and psychomotor impairment. Suvorexant's extended duration of action increases its risk to the public health relative to zolpidem (schedule IV) and other short acting sedatives. Results of the human abuse potential study showed that suvorexant produces behavioral impairment, as evidenced by its effects on psychomotor performance and cognitive function. On these assessments, suvorexant generally produced deficits that were statistically indistinguishable from 15 mg of zolpidem (schedule IV), demonstrating the behavioral impairing effects of suvorexant, and suggesting that even at therapeutic doses, suvorexant will present a risk to the public health that is at least equivalent to that of zolpidem (schedule IV).

7. Its Psychic or Physiological Dependence Liability: Results of the human abuse potential study demonstrate that suvorexant has a psychic dependence liability similar to zolpidem (schedule IV). Self-administration in laboratory animals, epidemiological data documenting its use and abuse, and the ability to produce “Drug Liking” in human drug users demonstrate the psychic dependence liability of zolpidem (schedule IV). Similar data was collected for suvorexant and compared to zolpidem.

Discontinuation studies suggest that suvorexant does not produce physical dependence or withdrawal syndrome. Observed effects following suvorexant discontinuation include the return of insomnia symptoms. Furthermore, a lack of tolerance in humans from suvorexant was demonstrated by the sustained efficacy of suvorexant in Phase 3 trials where subjects reported improvement in sleep-related assessments that were still present one month after the start of treatment.

8. Whether the Substance is an Immediate Precursor of a Substance Already Controlled under the CSA: Suvorexant is not an immediate precursor of a substance already controlled under the CSA.

Conclusion: After considering the scientific and medical evaluation conducted by the HHS, the HHS' recommendation, and its own eight-factor analysis, the DEA has determined that these facts and all relevant data constitute substantial evidence of a potential for abuse of suvorexant. As such, the DEA hereby proposes to schedule suvorexant as a controlled substance under the CSA.

The CSA outlines the findings required to place a drug or other substance in any particular schedule (I, II, III, IV, or V). 21 U.S.C. 812(b). After consideration of the analysis and recommendation of the Assistant Secretary for Health of the HHS and review of all available data, the Deputy Administrator of the DEA, pursuant to 21 U.S.C. 812(b)(4), finds that:

1. Suvorexant has a low potential for abuse relative to the drugs or other substances in schedule III. The overall abuse potential of suvorexant is comparable to schedule IV controlled substances such as zolpidem;

2. Upon approval of the pending new drug application, suvorexant will have a currently accepted medical use in the treatment of insomnia in the United States; and

3. The available evidence indicates that abuse of suvorexant may lead to limited psychological dependence relative to the drugs or other substances in schedule III. The potential for psychological dependence is similar to that of zolpidem (schedule IV).

Based on these findings, the Deputy Administrator of the DEA concludes that suvorexant ([(7 R )-4-(5-chloro-1,3-benzoxazol-2-yl)-7-methyl-1,4-diazepan-1-yl][5-methyl-2-(2 H -1,2,3-triazol-2-yl)phenyl]methanone), including its salts, isomers, and salts of isomers warrants control in schedule IV of the CSA. 21 U.S.C. 812(b)(4).

If this rule is finalized as proposed, suvorexant would be subject to the CSA's schedule IV regulatory controls and administrative, civil, and criminal sanctions applicable to the manufacture, distribution, dispensing, importing, exporting, research, and conduct of instructional activities, including the following:

Registration. Any person who handles (manufactures, distributes, dispenses, imports, exports, engages in research, or conducts instructional activities with) suvorexant, or who desires to handle suvorexant, would be required to be registered with the DEA to conduct such activities pursuant to 21 U.S.C. 822, 823, 957, and 958 and in accordance with 21 CFR parts 1301 and 1312. Any person who currently handles suvorexant, and is not registered with the DEA, would need to be registered with the DEA by the effective date of the final rule to conduct such activities pursuant to 21 U.S.C. 822, 823, 957, and 958, and in accordance with 21 CFR parts 1301 and 1312.

Security. Suvorexant would be subject to schedule III-V security requirements and would need to be handled and stored pursuant to 21 U.S.C. 821, 823, 871(b) and in accordance with 21 CFR 1301.71-1301.93.

Labeling and Packaging. All labels and labeling for commercial containers of suvorexant on or after finalization of this rule would need to comply with 21 U.S.C. 825, 958(e), and be in accordance with 21 CFR part 1302.

Inventory. Every DEA registrant who possesses any quantity of suvorexant on the effective date of the final rule would be required to take an inventory of all stocks of suvorexant on hand as of the effective date of the rule, pursuant to 21 U.S.C. 827, 958, and in accordance with 21 CFR 1304.03, 1304.04, and 1304.11(a) and (d).

Any person who becomes registered with the DEA after the effective date of the final rule would be required to take an initial inventory of all stocks of controlled substances (including suvorexant) on hand at the time of registration pursuant to 21 U.S.C. 827, 958, and in accordance with 21 CFR 1304.03, 1304.04, and 1304.11(a) and (b). After the initial inventory, every DEA registrant would be required to take a biennial inventory of all controlled substances (including suvorexant) on hand, on a biennial basis, pursuant to 21 U.S.C. 827, 958, and in accordance with 21 CFR 1304.03, 1304.04, and 1304.11.

Records. All DEA registrants would be required to maintain records with respect to suvorexant pursuant to 21 U.S.C. 827, 958, and in accordance with 21 CFR parts 1304, 1307, and 1312.

Prescriptions. All prescriptions for suvorexant or products containing suvorexant would need to comply with 21 U.S.C. 829, and be issued in accordance with 21 CFR part 1306, and part 1311 subpart C.

Importation and Exportation. All importation and exportation of suvorexant would need to be in compliance with 21 U.S.C. 952, 953, 957, and 958, and in accordance with 21 CFR part 1312.

Criminal Liability. Any activity involving suvorexant not authorized by, or in violation of, the CSA, occurring on or after finalization of this proposed rule, would be unlawful, and may subject the person to administrative, civil, and/or criminal sanctions.

In accordance with 21 U.S.C. 811(a), this proposed scheduling action is subject to formal rulemaking procedures performed “on the record after opportunity for a hearing,” which are conducted pursuant to the provisions of 5 U.S.C. 556 and 557. The CSA sets forth the procedures and criteria for scheduling a drug or other substance. Such actions are exempt from review by the Office of Management and Budget (OMB) pursuant to section 3(d)(1) of Executive Order 12866 and the principles reaffirmed in Executive Order 13563.

This proposed regulation meets the applicable standards set forth in Sections 3(a) and 3(b)(2) of Executive Order 12988 to eliminate drafting errors and ambiguity, minimize litigation, provide a clear legal standard for affected conduct, and promote simplification and burden reduction.

This proposed rulemaking does not have federalism implications warranting the application of Executive Order 13132. The proposed rule does not have substantial direct effects on the States, on the relationship between the national government and the States, or the distribution of power and responsibilities among the various levels of government.

This proposed rule will not have tribal implications warranting the application of Executive Order 13175. It does not have substantial direct effects on one or more Indian tribes, on the relationship between the Federal government and Indian tribes, or on the distribution of power and responsibilities between the Federal government and Indian tribes.

The Deputy Administrator, in accordance with the Regulatory Flexibility Act (RFA), 5 U.S.C. 601-612, has reviewed this proposed rule and by approving it certifies that it will not have a significant economic impact on a substantial number of small entities. The purpose of this proposed rule is to place suvorexant, including its salts, isomers, and salts of isomers, into schedule IV of the CSA. No less restrictive measures (i.e., non-control, or control in schedule V) enable the DEA to meet its statutory obligations under the CSA. In preparing this certification, the DEA has assessed economic impact by size category and has considered costs with respect to the various DEA registrant business activity classes.

Suvorexant is a new molecular entity which has not yet been marketed in the United States or any other country. Accordingly, the number of currently identifiable manufacturers, importers, and distributors for suvorexant is extremely small. The publicly available materials also specify the readily identifiable persons subject to direct regulation by this proposed rule. Based on guidelines utilized by the Small Business Administration (SBA), the suvorexant manufacturer/distributor/importer was determined not to be a small entity. Once generic equivalents are developed and approved for manufacturing and marketing, there may be additional manufacturers, importers, and distributors of suvorexant, but whether they may qualify as small entities cannot be determined at this time.

There are approximately 1.5 million controlled substance registrants, who represent approximately 381,000 entities (which include businesses, organizations, and governmental jurisdictions). The DEA estimates that 371,000 (97 percent) of these entities are considered “small entities” in accordance with the RFA and SBA standards. 5 U.S.C. 601(6); 15 U.S.C. 632. Due to the wide variety of unidentifiable and unquantifiable variables that potentially could influence the dispensing rates of new molecular entities, the DEA is unable to determine what number of these 371,000 small entities might handle suvorexant.

Despite the fact that the number of small entities possibly impacted by this proposed rule could not be determined, the DEA concludes that they would not experience a significant economic impact as a result of this proposed rule. The DEA estimates all anticipated suvorexant handlers to be DEA registrants and currently 98 percent of DEA registrants (most of which are small entities) are authorized to handle schedule IV controlled substances. Even assuming that all of these registrants were to handle suvorexant the costs that they would incur as a result of suvorexant scheduling would be nominal as they have already established and implemented the required security, inventory, recordkeeping, and labeling systems and processes to handle schedule IV controlled substances.

Because of these facts, this proposed rule will not result in a significant economic impact on a substantial number of small entities.

In accordance with the Unfunded Mandates Reform Act (UMRA) of 1995, 2 U.S.C. 1501 et seq., the DEA has determined and certifies that this action would not result in any Federal mandate that may result “in the expenditure by State, local, and tribal governments, in the aggregate, or by the private sector, of $100,000,000 or more (adjusted for inflation) in any one year. . . .” Therefore, neither a Small Government Agency Plan nor any other action is required under UMRA of 1995.

This action does not impose a new collection of information requirement under the Paperwork Reduction Act of 1995, 44 U.S.C. 3501-3521. This action would not impose recordkeeping or reporting requirements on State or local governments, individuals, businesses, or organizations. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB control number.

For the reasons set out above, the DEA proposes to amend 21 CFR part 1308 as follows:

Section 108(a) of the Clean Air Act directs the Administrator to issue “air quality criteria” for certain air pollutants. These air quality criteria are to “accurately reflect the latest scientific knowledge useful in indicating the kind and extent of all identifiable effects on public health or welfare, which may be expected from the presence of such pollutant in the ambient air. . . .” Under section 109 of the Act, EPA is then to establish National Ambient Air Quality Standards (NAAQS) for each pollutant for which EPA has issued criteria. Section 109(d) of the Act subsequently requires periodic review and, if appropriate, revision of existing air quality criteria to reflect advances in scientific knowledge on the effects of the pollutant on public health and welfare. EPA is also to revise the NAAQS, if appropriate, based on the revised air quality criteria.

NO X and SO X are two of six “criteria” pollutants for which EPA has established NAAQS. Periodically, EPA reviews the scientific basis for these standards by preparing an Integrated Science Assessment (ISA). The ISA, along with additional technical and policy assessments conducted by OAQPS, form the basis for EPA decisions on the adequacy of existing NAAQS and the appropriateness of new or revised standards.

This workshop is designed to inform the planning for EPA's recently initiated review of the secondary (welfare-based) NAAQS for Oxides of Nitrogen and Sulfur. The Federal Register notice issuing EPA's call for information for the recently initiated review is available at: http://www.epa.gov/ttn/naaqs/standards/no2so2sec/2013_fr.html . Consistent with the NAAQS review process, the workshop will provide an opportunity for those attending to highlight key science issues that they consider relevant to EPA's review of the standards (referred to as “policy- relevant issues”). More information on the NAAQS review process is provided at: http://www.epa.gov/ttn/naaqs/ . In workshop discussions, scientific experts will be expected to highlight significant new and emerging research on oxides of nitrogen and sulfur and make recommendations to the Agency regarding the design and scope of this review. The goal of the workshop is to ensure that EPA focuses on the key issues relevant to EPA's review of the NAAQS and considers the most meaningful new science to inform our understanding of these issues. Workshop discussions will provide important input as EPA considers the appropriate design and scope of major elements of the review that will inform the Agency's policy assessment. These elements include an integrated review plan (IRP) identifying the key policy-relevant issues; an integrated science assessment (ISA); and a risk and exposure assessment (REA). We intend that workshop discussions will build upon the following three publications:

• Secondary National Ambient Air Quality Standards for Nitrogen Dioxide; Final Rule ( 40 CFR part 50 [EPA-HQ-OAR-2007-1145], April 3, 2012 ). The preamble to the final rule included detailed discussions of policy-relevant issues central to the last review.

• Integrated Science Assessment for Oxides of Nitrogen and Sulfur—Ecological Criteria (EPA 600/R-08/082F, December 2008) .

• Risk and Exposure Assessment to Support the Review of the NO 2 Primary National Ambient Air Quality Standard (EPA 452/R-09/008a, September 2009) .

You can obtain copies of these and other related documents at: http://www.epa.gov/ttn/naaqs/standards/no2so2sec/index.html .

Drawing from the workshop discussions, EPA will develop a draft IRP. The IRP, in addition to summarizing the schedule and process for the review, will present approaches for evaluating the relevant scientific information; assessing risks to the environment; and addressing the key policy-relevant issues. The Clean Air Scientific Advisory Committee (CASAC) will be asked to review the draft IRP, and the public will have the opportunity to comment on it as well. The final IRP will be used as a framework to guide the review.

Table of Contents I. Background for these Proposed Actions II. Errors that EPA Made in the October 15, 2008, Rulemaking Approving Alabama's Visible Emissions SIP Revisions III. Basis of EPA's Proposal to Disapprove Alabama's SIP Revisions Related to Visible Emissions IV. Proposed Actions V. Statutory and Executive Order Reviews I. Background for These Proposed Actions

The State of Alabama, through ADEM, submitted SIP revisions to EPA on September 11, 2003, and August 22, 2008, to revise Alabama's SIP-approved visible emissions rule. EPA took final action approving Alabama's September 11, 2003, and August 22, 2008, SIP revisions (hereafter also referred to as the “Submittals”) on October 15, 2008. See 73 FR 60957. Subsequently, on April 6, 2011, EPA took final action to disapprove Alabama's Submittals. See 76 FR 18870. EPA's disapproval action was later vacated by the United States Court of Appeals for the Eleventh Circuit (hereafter also referred to as the “Court” or the “Eleventh Circuit Court of Appeals”). See below for more details on the Court's decision. A copy of this decision is in the docket  1 for this proposed rulemaking. The Court decision put back in effect EPA's October 2008, approval action. Today, EPA is reconsidering its October 2008 approval action, and is proposing to determine, pursuant to section 110(k)(6) of the CAA, that EPA's October 2008 approval of Alabama's SIP revisions (submitted September 11, 2003, and August 22, 2008) to change its EPA-approved visible emission rule (referred to hereafter as the “previous rule”) was in error. Consequently, EPA is also proposing to disapprove the aforementioned SIP revisions.

More detail on EPA's rationale for today's proposed actions is provided below. Specifically, Section II, below, outlines EPA's basis for proposing to determine that EPA erred in October 2008 when it approved the Submittals and thus the current, or “revised,” SIP rule. Section III provides the basis for EPA's proposed disapproval of the Submittals. Today's proposed disapproval action is consistent with the analysis that EPA laid out in the April 6, 2011, final disapproval action for these Submittals but is more specific than that action with regard to the errors EPA has determined were made by the 2008 approval action.

As mentioned above, EPA took action on October 15, 2008, to approve changes to Alabama's visible emissions rule that were submitted in SIP revisions on September 11, 2003, and August 22, 2008. See 73 FR 60957. Subsequently, on April 6, 2011, EPA took final action to disapprove Alabama's Submittals. See 76 FR 18870. EPA's April 6, 2011, final action was challenged in the Eleventh Circuit Court of Appeals by Alabama Power Company (joined through intervention by the State of Alabama). This case was ultimately consolidated with the pending but stayed challenges by the Alabama Environmental Council (AEC) and others to EPA's October 2008 approval of the Submittals. Following briefing and oral argument, the Eleventh Circuit Court of Appeals issued a 2-1 decision on March 6, 2013, vacating EPA's April 2011 disapproval action and affirming EPA's October 2008 approval action. See Alabama Environmental Council v. EPA, 711 F.3d 1277 (11th Cir. 2013). The majority opinion found that CAA section 110(k)(6) permits EPA to revise a SIP provision approved “in error” without any further submission from the State, so long as EPA provides the State and the public with its error determination and the basis thereof. See 711 F3d at 1287. Specifically, the Court explained: “Thus, if the EPA chooses to invoke Section 110(k)(6) to revise a prior action, Congress has required the EPA to articulate an `error' and provide `the basis' of its determination that an error occurred.” Id. Today, EPA is reconsidering its action in October 2008 to approve Alabama's Submittals, and is now proposing to determine pursuant to CAA 110(k)(6), that EPA's October 15, 2008, approval of Alabama's September 11, 2003, and August 22, 2008, SIP revisions related to visible emissions was in error, consistent with section 110(k)(6). Today, EPA is initiating a comment period regarding issues presented in this notice for the following reasons: (1) to provide the public with the basis of EPA's determination of what errors occurred; and (2) to outline EPA's rationale for disapproval of Alabama's Submittals. An overview of EPA's previous actions and other relevant background is provided below.

Section 110(k)(6) of the CAA provides EPA with the authority to make corrections to actions that are subsequently found to be in error. The key provisions of section 110(k)(6) for present purposes are that the Administrator has the authority to “determine[]” when a SIP approval was “in error,” and when the Administrator does so, may then revise the SIP approval “as appropriate,” in the same manner as the prior action, and do so without requiring any further submission from the State. As mentioned above, the Eleventh Circuit Court affirmed EPA's authority to use section 110(k)(6) to revise a prior action related to a state's implementation plan. See 711 F3d at 1287. While CAA section 110(k)(6) provides EPA with the authority to correct its own “error,” nowhere does this provision or any other provision in the CAA define what qualifies as “error.” Thus, EPA believes that the term should be given its plain language, everyday meaning, which includes all unintentional, incorrect or wrong actions or mistakes.

Additionally, the legislative history of CAA section 110(k)(6) is silent regarding the definition of error, but the timing of the enactment of the provision suggests a broad interpretation. The provision was enacted shortly after the U.S. Court of Appeals for the Third Circuit (hereafter referred to as the “Third Circuit Court”) decision in Concerned Citizens of Bridesburg v. U.S. EPA (hereafter referred to as “Bridesburg”), 836 F.2d 777 (3rd Cir. 1987). In Bridesburg, the Third Circuit Court adopted a narrow interpretation of EPA's authority to correct errors unilaterally. The Third Circuit Court stated that such authority was limited to typographical and other similar errors, and stated that any other change to a SIP must be accomplished through a SIP revision. Id. at 786.

In Bridesburg, EPA determined that it lacked authority to include odor regulations as part of a SIP unless the odor regulations had a significant relationship to achieving a national ambient air quality standard (NAAQS), and so the Agency directly acted to remove the 13-year-old odor provisions from the Pennsylvania SIP. Id. at 779-80. Specifically, EPA found the previous approval of the odor provisions into the SIP was an inadvertent error, and thus used its “inherent authority to correct an inadvertent mistake” to withdraw its prior approval of the odor regulations without seeking approval of the change from Pennsylvania. Id. at 779-80, 785. After noting that Congress had not contemplated the need for revision on the grounds cited by EPA, id. at 780, the Third Circuit Court found that EPA's “inherent authority to correct an inadvertent mistake” was limited to corrections such as “typographical errors,” and that instead EPA was required to use the SIP revision process to remove the odor provision from the SIP. Id. at 785-86.

When the Third Circuit Court made its determination in Bridesburg in 1987, there was no provision explicitly addressing EPA's error correction authority under the CAA. In 1990, Congress added section 110(k)(6) to the CAA. The legislative history of the CAA says little about the provision, and does not mention Bridesburg. Even so, the terms of the provision make it evident that Congress authorized EPA to undertake a broader set of revisions when correcting errors than the Bridesburg court read the pre-existing CAA to authorize, and that Congress did not intend to codify the holding of the Bridesburg decision. This is apparent because CAA section 110(k)(6) both: (1) authorizes EPA to correct SIP approvals and other actions that were “in error,” which, as noted previously, broadly covers any mistake, and thereby contrasts with the holding in the Bridesburg decision that EPA's pre-section 110(k)(6) authority was limited to correction of typographical or similar mistakes; and (2) provides that the error correction need not be accomplished via the SIP revision or SIP call process, which also contrasts with the holding of the Bridesburg decision requiring a SIP revision. By the same token, because the Bridesburg decision stood for the proposition that EPA could not correct anything more than a narrow range of typographical errors, had Congress intended to codify the decision in Bridesburg, it is logical that Congress would have described the type of error that EPA was authorized to correct in the same limited way that the decision did. In this manner, the fact that Congress adopted CAA section 110(k)(6) against the backdrop of the Bridesburg case confirms that the provision cover a broad range of errors.

EPA has used CAA section 110(k)(6) as authority to make substantive corrections to remove a variety of provisions from federally-approved SIPs that are not related to the attainment or maintenance of NAAQS or any other CAA requirement. See, e.g., “Approval and Promulgation of Implementation Plans; Kentucky: Approval of Revisions to the State Implementation Plan,” 75 FR 2440 (January 15, 2010) (correcting the SIP by removing a provision, approved in 1982, used to address hazardous or toxic air pollutants); “Approval and Promulgation of Implementation Plans; New York,” 73 FR 21546 (April 22, 2008) (issuing a direct final rule to correct a prior SIP correction from 1998 that removed general duties from the SIP but neglected to remove a reference to “odor” in the definition of “air contaminant or air pollutant”); “Approval and Promulgation of Implementation Plans; New York,” 63 FR 65557 (November 27, 1998) (issuing direct final rule to correct SIP by removing a general duty “nuisance provision” that had been approved in 1984); “Correction of Implementation Plans; American Samoa, Arizona, California, Hawaii, and Nevada State Implementation Plans,” 63 FR 34641 (June 27, 1997) (correcting five SIPs by deleting a variety of administrative provisions concerning variances, hearing board procedures, and fees that had been approved during the 1970s).

CAA section 110(k)(6), by its terms—specifically, the use of the terms “[w]henever” and “may”—authorizes, but does not require, EPA to make the specified finding. As a result, EPA has discretion in determining whether and when to make the specified finding and to utilize authority of section 110(k)(6). See New York Public Interest Research Group v. Whitman, 321 F.3d 316, 330-31 (2d Cir. 2003) (opening phrase “Whenever the Administrator makes a determination” in CAA section 502(i)(1) grants EPA “discretion whether to make a determination”); Her Majesty the Queen in Right of Ontario v. EPA, 912 F.2d 1525, 1533 (D.C. Cir. 1990) (“whenever” in CAA section 115(a) “impl[ied] a degree of discretion” in whether EPA had to make a finding). In addition, EPA has used CAA section 110(k)(6) authority to correct errors of a non-technical nature. Most recently, EPA withdrew its approval of SIP prevention of significant deterioration (PSD) programs in 24 states to the extent they apply PSD to Greenhouse Gas-emitting sources below the thresholds in the final Tailoring Rule. 2

Under both the pre-existing opacity restrictions in Alabama's SIP and the changes requested in Alabama's 2003 and 2008 submittals, the maximum number of six-minute periods  3 above the general 20 percent opacity limit allowed per day is the same—24. The maximum “average daily opacity” allowed under the previous rule is the same as the specific cap under the submittals—22 percent. On a quarterly basis, the total of exempt opacity exceedances allowed under the previous rule is 10 percent of operating time but is specifically capped under the submittals at 2 percent of operating time, while the maximum “average quarterly opacity” allowed is approximately the same—22 percent under the previous rule, and 21.6 percent under the submittals. 4

However, there are two significant differences  5 between the previous rule and the revised rule. The first significant difference is that the revised rule allows for maximum visible emissions of up to 100 percent opacity during 24 six-minute periods per day, while the previous rule allowed for maximum visible emissions of up to only 40 percent opacity during 24 six-minute periods per day. See Alabama Administrative Code (AAC) 335-3-4-.01(4) (revised rule). The second significant difference is that the revised rule allows opacity above the general 20 percent SIP standard for up to 2.4 consecutive hours ( i.e., an aggregate of 24 six-minute periods per calendar day), while the previous rule allowed exceedances of the 20 percent SIP standard for intervals of only 0.1 consecutive hours ( i.e., one six-minute period per hour). 6 A critical consideration, therefore, is whether the significant increase of the maximum allowable opacity from 40 percent to 100 percent for up to 2.4 consecutive hours per day could result in more PM emissions were sources to take advantage of the changed limits.

EPA first approved Alabama's visible emissions rule into the Alabama SIP in 1972. See 37 FR 10842, 10847 (May 31, 1972). The State submitted the visible emissions rule as part of its SIP for attainment and maintenance of the total suspended particulates (TSP) NAAQS (the predecessor to the Particulate Matter (PM) NAAQS). The State has revised its visible emission rule three times in support of those goals.

Historically, Alabama has had areas with attainment problems for the various PM NAAQS. Originally, EPA designated some areas in Alabama as nonattainment for the TSP NAAQS. In 1987, EPA replaced the TSP NAAQS with the PM 10 NAAQS, and all areas of Alabama were designated as attainment for those NAAQS. See 56 FR 11101 and 58 FR 67734. All areas of Alabama remain designated attainment for the PM 10 NAAQS. In 1997, EPA promulgated new annual and 24-hour particulate matter NAAQS, using PM 2.5 as the indicator. Effective April 5, 2005, EPA designated portions of Alabama, in the Birmingham and Chattanooga areas, as nonattainment for the 1997 PM 2.5 NAAQS. 7 8 The Chattanooga nonattainment area for the 1997 PM 2.5 NAAQS included a portion of Jackson County, Alabama. See 70 FR 944. Alabama's visible emissions rules at AAC 335-3-4-.01(4) continue to be a part of the Alabama SIP for attainment and maintenance of the PM NAAQS.

As mentioned above, Alabama submitted SIP revisions on September 11, 2003, and August 22, 2008, with changes to its visible emission rule. Specifically, the Submittals affect the applicable visible emissions limits at approximately 19 stationary source facilities. 9 These 19 facilities include older coal-fired utilities, cement manufacturing facilities, and pulp and paper facilities, among others. Five of these facilities are located in or near areas (e.g., Birmingham) that as of 2008 exceeded applicable PM 2.5 NAAQS. 10 In addition, Widows Creek Fossil Plant, operated by the Tennessee Valley Authority (TVA)), is located in the Chattanooga nonattainment area for the 1997 Annual PM 2.5 NAAQS. Other facilities affected by Alabama's visible emissions rule may also impact these or other areas.

Opacity may be defined as the degree to which emissions reduce the transmission of light and obscure the view of an object in the background. See 40 CFR 60.2. “Visible emissions” are pollutant discharges from a source that can be seen with the naked eye and are commonly measured as a percent of opacity. Opacity is an important emissions reduction tool because it provides information regarding pollutants leaving an emissions source and the effectiveness of the control equipment designed to capture those pollutants. In general, the more particles which scatter or absorb light that pass through an emissions point, the more light will be blocked, thus increasing the opacity percentage of the emissions plume. However, variables such as the size, number, and composition of the particles in the emissions can result in variations in the percentage of opacity.

Historically, visible emissions have been an important tool for implementation of PM NAAQS and, in particular, for the implementation and enforcement of PM limits on sources to help attain the NAAQS. The monitoring of visible emissions remains a useful technique for indicating the overall operation and maintenance of a facility and its emissions control devices and was employed even before modern instruments that measure PM on a direct, continuous basis existed. Observation of greater than normal visible emissions, particularly on a recurring basis, indicates that incomplete combustion or other changes to the process or the control device is or was occurring; such changes frequently lead to increased PM emissions. Although opacity is not a criteria pollutant, opacity standards continue to be used as an indicator of the effectiveness of emission controls for PM emissions, or to assist with implementation and enforcement of PM emission standards for purposes of attaining PM NAAQS. Further, well-maintained and well-operated sources should be able to achieve visible emissions that comply with opacity limits. For example, data submitted by one previous commenter to EPA's actions on Alabama's visible emission rule show routine source operation with opacity of about five percent. 11 Conversely, visible emissions at much higher percentages (such as those allowed by Alabama's revised rule), particularly on a recurring basis, may indicate that a source is emitting more PM and may be in violation of applicable SIP or permit PM mass limits as well. Alabama's Submittals would authorize sources to emit visible emissions of up to 100 percent opacity (the previous maximum opacity was 40 percent) for up to 2.4 consecutive hours per day  12 (the previous consecutive maximum time for sources to exceed the generally applicable 20 percent opacity standard was 6 minutes per hour). To be approvable, these changes must be consistent with CAA sections 110(l) and 193.

On October 15, 2008, EPA took final action to incorporate into the Alabama SIP, the changes to Alabama's visible emissions rule included in the Submittals. See 73 FR 60957. EPA's rationale for its approval is discussed in that final action. EPA's approval of the SIP revisions relied on two main findings: “(1) the revision would not increase the allowable average opacity levels; and (2) the relationship between changes in opacity and increases or decreases in ambient PM 2.5 levels cannot be quantified readily for the sources subject to this SIP revision, and is particularly uncertain for short-term analyses.” See 73 FR 60959. EPA's October 15, 2008, final action was effective on November 14, 2008 (by its terms, the Alabama rule change became effective, and thus applicable to sources, on May 14, 2009).

Following the October 2008 final action, EPA received two petitions for reconsideration submitted on behalf of AEC and other parties (Petitioners), one on December 12, 2008, and one on February 25, 2009. EPA considered these petitions under section 553(e) of the Administrative Procedures Act (APA) and the CAA. The first petition for reconsideration raised procedural and substantive concerns with EPA's October 2008 final action. 13 EPA denied the December 12, 2008, petition via letter on January 15, 2009. The second petition incorporated by reference the issues raised in the first petition and also identified additional substantive and procedural concerns not included in the first petition. 14 EPA granted the second petition for reconsideration of the October 2008 final action via letter on April 3, 2009. In that letter, EPA explained that it anticipated initiating a new rulemaking process to provide additional opportunities for public comment on issues raised in the petition for reconsideration. On December 12, 2008, Petitioners filed a lawsuit in the Eleventh Circuit Court of Appeals challenging EPA's October 2008 final action. The Court subsequently stayed the litigation pending the conclusion of EPA's reconsideration process.

On October 2, 2009, EPA proposed to initiate a new rulemaking process to reconsider its prior action on the Submittals. See 74 FR 50930. In that proposal, EPA articulated two alternative options and sought public comment on both. One option was to affirm the October 2008 final action (thus approving Alabama's SIP revisions) and the other was to amend the October 2008 final action (thus disapproving Alabama's SIP revisions). The bases for each alternative were described in detail in the October 2, 2009, proposed rulemaking. See 74 FR 50932-50934. EPA thus undertook full notice and comment again on the substantive issues relevant to the SIP revisions. EPA received numerous comments on its October 2, 2009, proposed rule.

In EPA's April 6, 2011, final action, EPA explained the basis of its determination that the Submittals were not approvable. EPA began by explaining: “In light of the fact that this SIP revision would apply statewide, including nonattainment areas, EPA has concluded that it cannot approve the SIP revision under section 110(l) if it would worsen air quality by allowing increased emissions of criteria pollutants or precursors to such criteria pollutants.” See 76 FR 18871. EPA then discussed the role of visible emissions in NAAQS attainment and maintenance, highlighting that historically, visible emissions have been an important tool for implementation of the PM NAAQS and, in particular, for the implementation and enforcement of PM limits on sources to help attain, and maintain, the NAAQS. See 76 FR 18872. EPA explained that while sources submitted data during the comment period on the October 2009 proposal that suggested routine source operation of about five percent opacity, visible emissions at much higher percentages such as those allowed by the Submittals (which allow for opacity of up to 100 percent), particularly on a recurring basis, may indicate that a source is in violation of particulate matter emission limits in the SIP or individual source permits. See 76 FR 18872.

Though EPA's October 2009 Federal Register notice requested specific data on the correlation between opacity and particulate matter emissions, EPA received no such data obtained from any of the 19 sources that would be affected by the Submittals. See 76 FR 18872 and 74 FR 50934. As EPA explained in the April 6, 2011, final action, the Submittals included two key rule changes to the existing EPA-approved opacity standards that effectively allowed for increases in opacity emissions from the 19 older facilities which may not have state-of-the-art control equipment but which are subject to the rule. The first significant change was the allowance of maximum visible emissions of 100 percent opacity during certain periods while the previous rule allowed for maximum visible emissions of only 40 percent opacity. See 76 FR 18874. The second significant change was that the revised rule allowed for opacity to increase up to 100 percent for 2.4 consecutive hours, which Petitioners referred to as the “bundling” of high opacity periods, whereas the previous visible emissions standard did not allow for such bundling and restricted the opacity increases to six minutes per hour. Id.

As discussed in more detail above, EPA's April 6, 2011, final action was challenged in the Eleventh Circuit Court of Appeals by Alabama Power Company (joined through intervention by the State of Alabama). In a 2-1 decision on March 6, 2013, the Court vacated EPA's April 2011 disapproval action and affirming EPA's October 2008 approval action. Alabama Environmental Council v. EPA, 711 F.3d 1277 (11th Cir. 2013). The majority opinion found that CAA section 110(k)(6) permits EPA to revise a SIP provision approved “in error” without any further submission from the State, so long as EPA provides the state and the public with its error determination and the basis thereof. See 711 F.3d at 1281. Specifically, the Court explained: “Thus, if the EPA chooses to invoke Section 110(k)(6) to revise a prior action, Congress has required the EPA to articulate an `error' and provide `the basis' of its determination that an error occurred.” Id. at 1287.

When EPA took action on Alabama's visible emission rule changes in 2008, the Birmingham Area was designated nonattainment for the 1997 Annual PM 2.5 NAAQS, and EPA was in the process of designating this same area as nonattainment for the 2006 24-hour PM 2.5 NAAQS. Additionally, a portion of Jackson County (in association with the Chattanooga area) was designated nonattainment for the 1997 Annual PM 2.5 NAAQS. The geographic location of affected sources covered by the visible emission rules in the EPA-approved SIP is relevant. This is because (as is discussed more fully below) EPA interprets section 110(l) to prohibit approval of SIP revisions that would increase emissions of pollutants for which an area is designated nonattainment, in the absence of offsetting emission reductions or an attainment demonstration addressing the rule changes at issue. Further, under section 193 (which was not considered in the October 2008 approval—a matter that EPA is now proposing to determine was an error), an evaluation of the impacts of changes to Alabama's visible emissions rule was required for the nonattainment areas because the rule was in place prior to the 1990 amendments to the CAA.

EPA is proposing to determine, pursuant to CAA section 110(k)(6), that its 2008 approval of Alabama's 2003 and 2008 SIP submittals was in error. EPA is providing the specific error determinations and the basis for each determination below.

In its 2008 action approving Alabama's 2003 and 2008 SIP submittals, EPA conceded that “modeling presented by commenters show[ed] the possibility of an impact on the NAAQS under a worst-case scenario.” See 73 FR 60962. EPA noted, however, that “the modeling does not convincingly demonstrate the impact of the rule change on the NAAQS because the level of PM emissions while operating at 100 percent opacity, and the source-specific relationship between opacity and PM emissions, are uncertain and are not demonstrated in the public record.” Id. (emphasis added). EPA further explained that “the relationship between changes in opacity and increases or decreases in ambient PM 2.5 levels cannot be quantified readily for the sources subject to this SIP revision, and is particularly uncertain for short-term analysis.” See 73 FR 60959 (emphasis added). Based in part on this finding of uncertainty regarding the actual air quality impacts of the requested SIP revisions and EPA's interpretation of CAA section 110(l) as only barring EPA's approval of a requested SIP revision if “the agency finds it will make air quality worse” ( see 73 FR 60960), EPA concluded that the proposed revisions satisfied the requirements of CAA section 110(l) with respect to the 24-hour PM NAAQS. See 73 FR 60959. In other words, under EPA's 2008 interpretation of section 110(l), a SIP relaxation “would interfere” with NAAQS attainment and maintenance only where EPA is able to determine that it is more likely than not that the revision would worsen air quality. Because EPA concluded that data uncertainty prevented it from making that determination with respect to Alabama's SIP revisions, EPA concluded that it was approvable under section 110(l). As explained below, EPA now proposes to conclude that the interpretation of section 110(l) that EPA relied on for purposes of its 2008 approval of Alabama's requested SIP revisions was erroneous. Because EPA's 2008 final action depended on that erroneous statutory interpretation, EPA's approval of Alabama's requested SIP revisions was itself in error.

EPA's proposed conclusion that it erred in interpreting CAA section 110(l) as barring EPA's approval of a SIP relaxation only where EPA is able to conclude that it is more likely than not that the relaxation will make air quality worse is based on its view that this interpretation does not adequately implement section 110(l) in light of the CAA's purpose “to protect and enhance the quality of the Nation's air resources so as to promote the public health and welfare and the productive capacity of its population,” CAA section 101(b)(1). Specifically, given the technical complexity of assessing how a particular SIP revision will impact air quality, it may be difficult—or even impossible—to determine in advance whether a requested SIP revision will make air quality worse. Thus, an interpretation of the phrase “would interfere” in CAA section 110(l) that allows EPA to approve a SIP revision that relaxes existing SIP requirements despite significant uncertainty regarding whether the change will worsen air quality could well result in EPA approving SIP revisions that actually do worsen air quality, which would be contrary to the express purpose and requirements of section 110(l). While EPA could then attempt to remedy the problem by issuing a SIP call under CAA section 110(k)(5), compliance with SIP call procedures typically takes more than a year, and sometimes much longer. In the meantime, the public would be exposed to elevated air pollution levels. Thus, EPA finds that its 2008 approach of approving a SIP relaxation despite significant uncertainty as to whether the relaxation ultimately will worsen air quality was in error because such interpretation is inconsistent with section 110(l) and with EPA's responsibility under CAA section 101(b)(1) “to protect and enhance the quality of the Nation's air resources so as to promote the public health and welfare.”

EPA now concludes that it should assume that a SIP revision that relaxes an existing SIP requirement “would interfere” with NAAQS attainment and maintenance in the absence of record evidence demonstrating that it would not. This assumption makes sense given that States adopt (and EPA approves) SIP requirements for the purpose of attaining and maintaining the NAAQS. Thus, it should be assumed that any existing SIP requirement is needed for that purpose, and if a State wishes to revise or remove a SIP requirement, such request must be accompanied by a demonstration that the revision would not interfere with NAAQS attainment or maintenance.

EPA's interpretation of CAA section 110(l) does not mean that a small possibility that a SIP revision might allow increased pollution that would interfere with NAAQS attainment or maintenance necessitates EPA's disapproval. EPA recognizes that attainment planning generally requires a high degree of technical judgment and often involves some degree of uncertainty. Thus, under EPA's interpretation of CAA section 110(l), EPA can approve a SIP relaxation if the State demonstrates either that it is unlikely that the revision would allow increased pollution or that any increases allowed by the revision would not be enough to interfere with NAAQS attainment or maintenance. Where data uncertainty prevents such a demonstration, however, EPA will assume that that the relaxation would interfere with NAAQS attainment or maintenance. EPA cannot, as it did in its 2008 action approving Alabama's 2003 and 2008 SIP submittals, rely on uncertainty regarding whether a SIP relaxation would make air quality worse as the basis for concluding that a revision is approvable under CAA section 110(l).

Even applying its 2008 interpretation of CAA section 110(l)—which EPA now concedes was erroneous—EPA proposes to conclude that it erred in finding that uncertainty regarding the precise relationship between changes in opacity levels and increases or decreases in PM emissions meant that the record was insufficient to support a finding that the requested SIP revisions would interfere with attainment and maintenance of the PM NAAQS ( see 73 FR 60959). While information in the record was insufficient to quantify the precise impact that the requested revisions would have on PM emissions, EPA now proposes to find that available information was sufficient to conclude that Alabama's SIP revisions would allow longer periods of elevated opacity that would, in some circumstances, allow increased PM emissions and would interfere with NAAQS attainment and maintenance.

Under EPA's 2008 interpretation of CAA section 110(l), a determination that Alabama's requested SIP revisions would more likely than not allow a PM emissions increase would have precluded EPA's approval absent other information demonstrating that such an emissions increase would not interfere with NAAQS attainment and maintenance. However, EPA determined that the uncertainty as to whether the SIP revisions would allow a PM emissions increase was so great that no likelihood could be estimated and found that this uncertainty made the revisions approvable under section 110(l). As discussed below, after reconsidering information in the record, EPA's judgment is that there is a relationship between opacity and PM emissions that supports a finding that Alabama's requested SIP revisions would, more likely than not, authorize increased PM emissions in some cases that would interfere with attainment and maintenance of the PM NAAQS.

First, EPA observes that there is a general relationship between opacity and PM emissions such that an increase in opacity means the concentration of smaller particles, larger particles, or both, increases. See, e.g., Malm, William C., “Introduction to Visibility,” Cooperative Institute for Research in the Atmosphere, May 1999 at Chap. 2, p. 8. See also Comments of the Utility Air Regulatory Group on EPA's Proposed Approval of Revisions to the Visible Emissions Portion of the Alabama Implementation Plan (Docket I.D EPA-R04-OAR-2005-AL-0002-0012), at 4 (noting that “an increase in opacity can be a good indication that PM emissions at the stack also are increasing”). Because increases in the quantity of smaller particles may be accompanied by decreases in the quantity of larger particles, and vice versa, opacity increases do not always reflect corresponding increases in the mass of PM emissions. Furthermore, while source-specific relationships between opacity and PM emissions may be obtained through testing, they can be influenced by a variety of circumstances such as fuel composition and types of equipment malfunction that may occur. However, uncertainty about the precise correlation between PM mass emissions and opacity as a general matter does not mean that opacity increases never represent concurrent increases in the mass of PM emissions from a source. To the contrary, given the large increases in maximum allowable opacity and for the periods of time at issue in the SIP revisions contemplated in Alabama's 2003 and 2008 submittals, EPA proposes to conclude that it is likely that the requested SIP revisions would allow increased PM emissions.

Second, EPA notes that Alabama's SIP revisions likely would allow PM emission increases because the revisions authorize higher opacity levels for longer periods than allowed under the existing SIP opacity rule. In EPA's experience, a longer period of high opacity (e.g., 100 percent opacity or other high opacity levels over a time period of an hour or longer) is more likely to indicate a problem with a control device—and, therefore, to correlate with an emission increase—than high opacity over a shorter period (e.g., 20 percent to 40 percent opacity over six minutes). Yet under Alabama's requested SIP revisions, a control device could temporarily shut down or malfunction, resulting in 100 percent opacity for up to 2.4 hours in a single day without causing any violation of the opacity standard. As a result, Alabama's requested SIP revisions undermine one of the primary purposes of opacity limits: To ensure that sources properly maintain and operate their PM control devices.

In contrast, Alabama's previous SIP opacity limit, by requiring consistent compliance at 20 percent and allowing only one excursion of six minutes per hour of up to 40 percent opacity, provides a greater incentive for sources to control their PM emissions with properly maintained and operated control devices. In EPA's judgment, based on experience, a source equipped with properly maintained and operated PM control devices is capable of consistently achieving low opacity levels. This conclusion is supported by the experience with the Colbert plant in Alabama, where the TVA undertook improvements to minimize opacity that included such items as training personnel, tracking opacity more closely, and upgrading equipment. See Sierra Club v. Tennessee Valley Authority, 592 F. Supp. 2d 1357 (N.D. Ala. 2009). A district court concluded that as a result of these changes, “Colbert Unit 5 is capable of operating with essentially no non-exempt COMS [Continuous Opacity Monitoring System] readings over 20%.” Id. at 1369. The district court further observed that once TVA became aware that it needed to comply with the opacity limit during all non-exempt periods, “it immediately and consistently came into compliance with the 20% opacity limit in the SIP.” Id. at 1370.

While various entities provided EPA with modeling results to aid in assessing the impact that Alabama's requested SIP revisions would have on ambient air quality, EPA proposes to conclude that none of the models reliably demonstrates the likely impact of the requested changes to Alabama's visible emissions rule on PM emissions. Significantly, the utility of all of the modeling data is undermined by the lack of source-specific data on the mass-opacity relationship. The docket for this action includes a TSD summarizing the modeling that EPA received and some of the key assumptions and other issues that impacted the utility of the modeling. Because of the weaknesses of the underlying data and assumptions used in the modeling, none of the modeling results are sufficient to rebut the information described above suggesting that Alabama's requested revisions to SIP opacity restrictions would correlate with increased PM emissions.

Taken together, the observations described above lead EPA to conclude there is a relationship between opacity and PM emissions such that the opacity increases allowed by Alabama's requested SIP revisions would more likely than not be associated with increased PM emissions in some cases, thereby worsening air quality. Under EPA's longstanding interpretation of section 110(l), a SIP relaxation that likely would result in increased emissions, particularly in areas that are not attaining the NAAQS, cannot be approved absent a contemporaneous attainment demonstration or other air quality analyses demonstrating that the revision will not interfere with attainment or maintenance of the NAAQS.

For example, in 2005, EPA proposed to disapprove a SIP revision submitted by Ohio that would have relaxed opacity limitations for sources that utilize a continuous opacity monitoring system. See 70 FR 36901 (June 27, 2005). Specifically, Ohio's proposed SIP revision would have expanded the time that such sources could operate with opacity levels above the generally applicable standard in the existing SIP. See 70 FR 36902. Under the revision, the time of such additional excess opacity values could represent up to 1.1 percent of a source's operating time per quarter. Id. In proposing to disapprove Ohio's requested revision, EPA explained that though the revision would not increase the total allowable time of excess opacity, “the revised rules allow excess opacity on occasions that excess opacity is currently prohibited, without any compensating prohibitions of emissions that are currently allowed.” See 70 FR 36903. Based on that observation, EPA concluded that “the revised rule clearly allows emissions that are prohibited by the current SIP.” Id. Noting that CAA section 110(l) prohibits EPA from approving a SIP revision that would interfere with any applicable requirement concerning attainment or any other applicable CAA requirement, EPA explained: “Ohio provided no analysis or demonstration that the emissions that are allowed by its revised rule but are prohibited by the current SIP would not interfere with attainment or other applicable requirements. Therefore, EPA must disapprove this revised rule.”  15 Id.

As in the case of Ohio's requested relaxation of SIP opacity limits, the record for Alabama's requested SIP revisions lacks additional information sufficient to rebut the presumption that the relaxation of Alabama's SIP opacity requirements would interfere with attainment and maintenance of the PM NAAQS. Following reconsideration and a complete review of the record, EPA proposes to conclude that available information was, in fact, sufficient to support a conclusion that Alabama's requested SIP revisions would interfere with attainment and maintenance of the PM NAAQS. Thus, EPA's 2008 determination that Alabama's requested SIP revisions were approvable under section 110(l) and its action approving the relaxation based on that conclusion were erroneous.

Aside from uncertainty, EPA also based its 2008 approval of Alabama's 2003 and 2008 SIP revisions, in part, on its determination that a source's allowable daily average and quarterly average opacity levels would not change as a result of the revisions. See 73 FR 60959. With respect to average daily opacity, this conclusion was based on a provision in Alabama's requested SIP revisions providing that a source's average daily opacity may not exceed 22 percent, excluding periods of startup, shutdown, load change and rate change (or other short intermittent periods upon terms approved by ADEM's Director and included in a State-issued permit). Id. Though Alabama's Submittals did not include a similar limit on average quarterly opacity, EPA “calculated the `average quarterly opacity' allowed under both the existing SIP and the proposed revisions and showed that the proposed revision, with changes specified in the notice [of proposed rulemaking], would result in no greater average quarterly opacity allowed than what is allowed under the current standard.” See 73 FR 60959. As explained below, EPA now proposes to conclude that it erred by relying on average daily and quarterly opacity as a means for evaluating whether the requested SIP revisions would interfere with attainment or maintenance of the annual and 24-hour PM NAAQS.

As discussed above, a primary purpose of opacity limits is to ensure that sources properly maintain and operate their PM control devices. Moreover, longer periods of high opacity are more likely than shorter periods to indicate a control device problem. Under Alabama's requested SIP revisions, a control device could temporarily shut down or malfunction, resulting in 100 percent opacity for up to 2.4 hours, yet the source could still be in compliance with the 22 percent average daily limit (and experience no change in its average quarterly opacity level). For example, in one day, a source that has 24 consecutive six-minute periods of 100 percent opacity but remains below an average of 13 percent opacity for the remaining 216 six-minute periods in the day would meet the 22 percent average daily opacity limit. 16 By “averaging away” such long periods of high opacity, Alabama's revised rule allows high opacity to be excused during precisely those periods that are expected to be associated with increased PM emissions. Thus, determining that Alabama's requested SIP revisions would not allow a source to increase its average quarterly or average daily opacity levels provides no basis for determining that the revisions will not allow a source to increase its PM emissions. Because EPA erroneously relied in part on its finding that average quarterly and average daily allowable opacity levels would not be affected by Alabama's requested SIP revisions in finding that the revisions were approvable under section 110(l), EPA proposes to conclude that its 2008 approval action was itself erroneous.

In approving Alabama's requested SIP revisions in 2008, EPA also erred by failing to recognize that Alabama's requested SIP revisions functionally established an automatic exemption from an emission limitation in violation of CAA section 302(k), 42 U.S.C. 7602(k). If EPA had correctly identified this issue, EPA would not have taken the 2008 action approving Alabama's 2003 and 2008 SIP submittals, nor would it have been authorized to do so. See CAA section 110(l) (“The Administrator shall not approve a revision of a plan if the revision would interfere with any applicable requirement concerning attainment and reasonable further progress . . . or any other applicable requirement of this chapter.” (emphasis added). Therefore, EPA proposes to conclude that its failure to recognize that Alabama's requested SIP revisions violated section 302(k) rendered its 2008 approval action erroneous and in need of correction under CAA section 110(k)(6).

The section 302(k) violation arises from the provision in Alabama's requested SIP revisions that authorizes, for sources that meet the revised rule's criteria, up to 24 six-minute averages of 100 percent opacity per calendar day. 17   See AAC Chapter 335-3-4-.01(4). Because 100 percent opacity is the maximum level of opacity possible, the allowance of up to 24 six-minute averages of 100 percent opacity per calendar day functionally equates to an exemption from the otherwise applicable SIP emission limitation for those periods. 18

Section 302(k) defines “emission limitation” for CAA purposes, in relevant part, as “a requirement . . . which limits the quantity, rate, or concentration of emissions of air pollutants on a continuous basis. . . .”  19 Alabama's opacity rule is incorporated into Alabama's SIP to satisfy CAA section 110(a)(2)(A), which requires that each SIP 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.” (emphasis added). Thus, Alabama's opacity rule constitutes an “emission limitation” under the CAA and is subject to that term's definition in CAA section 302(k). By functionally carving out an exemption from the opacity limitation for up to 24 six-minute averages per day, Alabama's requested SIP revisions contravene section 302(k)'s unambiguous requirement that an emission limitation restrict emissions “on a continuous basis.” See, e.g., Sierra Club v. EPA, 551 F.3d 1019, 1027-1028 (D.C. Cir. 2008) (vacating an exemption for startup, shutdown, and malfunction periods contained in federal regulations issued under CAA section 112 on the basis that “[w]hen sections 112 and 302(k) are read together,” the CAA “require[es] that some section 112 standard apply continuously.”); US Magnesium, LLC v. EPA, 690 F.3d 1157, 1170 (10th Cir. 2012) (denying a petition for review challenging EPA's issuance of a section 110(k)(5) SIP call requiring Utah to revise its SIP to eliminate a provision that automatically exempted sources from SIP compliance during unavoidable equipment breakdowns; the SIP call was based, inter alia, on section 302(k)'s requirement that emission limitations apply on a continuous basis).

In a recent proposed rulemaking, EPA explained as a technical, legal and policy matter why rules that authorize automatic exemptions from emissions limits are inconsistent with the CAA and thus, unlawful. 78 FR 12460 (February 22, 2013) (“State Implementation Plans: Response to Petition for Rulemaking; Findings of Substantial Inadequacy; SIP Calls to Amend Provisions Applying to Excess Emissions During Periods of Startup, Shutdown and Malfunction,” referred to as the “SSM proposal”). Although the SSM proposal provides a useful synopsis of the applicable requirements under the CAA, EPA's position that the CAA prohibits automatic exemptions from SIP emission limitations has remained unchanged since at least 1982. See 78 FR 12489. The rationale provided in the SSM proposal for why SSM exemptions are contrary to the CAA's language and purpose applies equally to Alabama's requested opacity exemption.

When approving Alabama's requested SIP revisions in 2008, EPA responded to a public comment asserting that EPA's approval of Alabama's revised rule would violate section 302(k) in that it “would be approving an `automatic exemption' from certain emission limitations that must function on a `continuous basis.”' See 73 FR 60960. At the time, EPA responded that rather than creating an exemption from the rule, Alabama's SIP submittal involved “revisions to the rule itself.” Id. EPA contended that “[a] source that meets the requirements of the revised standard will be in continuous compliance with the standard.” Id. EPA also stated: “The provisions of the CAA and its implementing regulations cited by the commenters do not require that all SIP measures require compliance with the same numerical emission limitation at all times.” Id. Based on that analysis, EPA contended Alabama's requested SIP revisions did not violate section 302(k). See 73 FR 60960. EPA now proposes to conclude that its 2008 analysis of whether Alabama's requested SIP revisions violated section 302(k) was erroneous. First, EPA's argument in 2008 that Alabama's revised rule allowing periods of 100 percent opacity is lawful because the amended regulatory language appears in “the rule itself” is contrary to CAA section 302(k)'s plain language, which expressly requires that the “emission limitation” itself limit emissions on a continuous basis. Section 302(k) is not satisfied simply by requiring continuous compliance with a standard that does not itself apply on a continuous basis. Second, while EPA continues to agree with its statement in 2008 that SIP measures need not “require compliance with the same numerical emission limitation at all times” (emphasis added), EPA disagrees with the implication in EPA's 2008 response that Alabama's allowance of 100 percent opacity for up to 24 six-minute averages per day constitutes a “numerical emission limitation” at all. Rather, as explained above, because 100 percent opacity is the maximum opacity level possible, the revised rule's allowance of up to 24 six-minute averages of 100 percent opacity per calendar day functionally equates to an exemption from the emission limitation for those periods. As a result, many opacity exceedances that would have been violations of the previous rule are now exempted under the revised rule. Thus, EPA now proposes to conclude that the SIP revision requested in Alabama's 2003 and 2008 submittals do, in fact, violate section 302(k), and therefore, that EPA's 2008 action approving Alabama's requested SIP revisions was erroneous.

In approving Alabama's requested SIP revisions in 2008, EPA also erred by failing to consider whether the requested revision was consistent with CAA section 193. Section 193 provides: “No control requirement in effect . . . before November 15, 1990, in any area which is a nonattainment area for any air pollutant may be modified after November 15, 1990, in any manner unless the modification insures equivalent or greater emission reductions of such air pollutant.” See 42 U.S.C. 7515. Congress added this provision in the 1990 Amendments as part of an effort to ensure adequate support for NAAQS attainment and maintenance. Consistent with the provision's plain text, Congress' intent in adopting this provision was to provide a `back-up' anti-backsliding provision for nonattainment areas beyond what was provided by 110(l). 20 Because Alabama's 2003 and 2008 SIP submittals proposed to revise a “control requirement” that was “in effect before November 15, 1990” and that applied to PM nonattainment areas (see section I.D. above), EPA's 2008 action should have included an analysis for why Alabama's requested SIP revisions did not contravene CAA section 193. Because such an analysis is a critical prerequisite to approving any modification to a pre-1990 control requirement, EPA proposes to conclude that the lack of such an analysis made EPA's 2008 approval of Alabama's 2003 and 2008 SIP submittals erroneous. 21

Upon reconsideration of available information, and in light of the errors in EPA's 2008 analysis described above, EPA now proposes pursuant to its error correction authority under CAA section 110(k)(6) to disapprove Alabama's 2003 and 2008 SIP revisions.

As explained above, upon reconsideration of the available information, EPA now proposes to conclude that Alabama's requested SIP revisions would interfere with attainment and maintenance of the PM NAAQS and are therefore not approvable under CAA section 110(l). Specifically, in EPA's technical judgment, the increased opacity levels authorized by Alabama's revised rule would, more likely than not, be associated with increased PM emissions in some cases. Under circumstances such as this where EPA concludes that a SIP revision would allow increased emissions, EPA assumes that the relaxation would interfere with NAAQS attainment and maintenance in the absence of a contemporaneous attainment demonstration or other air quality analyses demonstrating that the relaxation will not, in fact, interfere with NAAQS attainment and maintenance. Because Alabama made no such demonstration, EPA proposes to conclude that Alabama's 2003 and 2008 SIP revisions are not approvable under CAA section 110(l). Therefore, pursuant to its error correction authority under CAA section 110(k)(6), EPA now proposes to disapprove Alabama's 2003 and 2008 Submittals.

EPA's proposed conclusion that Alabama's requested SIP revisions “would interfere” with PM NAAQS attainment and maintenance and therefore is not approvable under CAA section 110(l) remains the same regardless of whether EPA applies its current interpretation of CAA section 110(l) or its 2008 interpretation. The fundamental difference between these two interpretations pertains to how they address uncertainty regarding whether a SIP relaxation would allow increased emissions. Under the 2008 interpretation, EPA assumed that a SIP relaxation would not interfere with NAAQS attainment and maintenance unless available information demonstrated that, more likely than not, the relaxation would allow increased emissions. Under EPA's current interpretation, EPA assumes that a SIP relaxation would allow increased emissions, and thereby interfere with NAAQS attainment and maintenance, unless available information indicates that, more likely than not, the revision will not allow increased emissions. In other words, in the face of uncertainty, EPA's current interpretation of CAA section 110(l) errs on the side of protecting air quality. However, in EPA's technical judgment, available information is sufficient to demonstrate that, more likely than not, Alabama's 2003 and 2008 Submittals would allow increased PM emissions in some circumstances. Thus, even under EPA's less protective 2008 interpretation, EPA now proposes to conclude that Alabama's 2003 and 2008 Submittals are not approvable under CAA section 110(l).

In addition to interfering with attainment and maintenance of the PM NAAQS, EPA proposes to conclude that Alabama's requested SIP revisions are not approvable under CAA section 110(l) because it interferes with the requirements of CAA section 302(k). Specifically, as explained earlier in this notice, CAA section 302(k) requires that any “emission limitation” adopted under the CAA apply “on a continuous basis,” and Alabama's SIP opacity rule constitutes an “emission limitation” that must meet CAA section 302(k)'s requirements. By authorizing emissions with up to 100 percent opacity for up to 24 six-minute averages per day, Alabama's revised opacity rule effectively exempts sources from compliance with opacity restrictions during those periods. As a result, the revised opacity rule would not apply to sources “on a continuous basis,” in contravention of CAA section 302(k). For this additional reason, EPA proposes to conclude that Alabama's 2003 and 2008 SIP submittals are not approvable under CAA section 110(l).

Under CAA section 193, “[n]o control requirement in effect . . . before November 15, 1990, in any area which is a nonattainment area for any air pollutant may be modified after November 15, 1990, in any manner unless the modification insures equivalent or greater emission reductions of such air pollutant.” As discussed above, because Alabama's opacity requirements were incorporated into the SIP well before November 15, 1990, and because the requested opacity revision applied in nonattainment areas, EPA should have evaluated whether Alabama's 2003 and 2008 Submittals complied with CAA section 193 prior to its 2008 approval action. EPA notes that when correcting an error pursuant to section 110(k)(6), we must evaluate whether there was an error in light of the circumstances that existed at the time of the original action. Subsequent to its 2008 approval action, EPA redesignated most of Alabama's PM nonattainment areas to attainment. Nonetheless, one Alabama area continues to be designated nonattainment for the 1997 PM 2.5 NAAQS: the Jackson County portion of the Chattanooga nonattainment area. 22 Section 193 is applicable for nonattainment areas until such time that EPA takes final action to redesignate an area to attainment. 23 Thus, whether evaluated under the facts and circumstances of 2008 or today, Alabama's requested SIP revisions must satisfy section 193 to be approvable.

Given EPA's conclusion that the opacity increases authorized by Alabama's requested SIP revision would, more likely than not, be associated with increased PM emissions in some cases, CAA section 193 bars EPA's approval unless the State demonstrates that its 2003 and 2008 SIP revisions offset such PM increases with equivalent or greater emission reductions. Nothing in the record for this action indicates that the Submittals include any mechanism to obtain such offsetting PM emission reductions. Therefore, EPA proposes to conclude that Alabama's 2003 and 2008 Submittals do not meet section 193's requirements and, as a result, must be disapproved.

Today, EPA is proposing to take action to reconsider its previous approval of Alabama's visible emission rule in October 2008. In summary, EPA is proposing to determine, pursuant to CAA section 110(k)(6), that it erred in approving the Submittals (dated September 11, 2003, and August 22, 2008) in 2008 for the reasons outlined in Section II of this proposed rulemaking. Consequently, EPA is also proposing to disapprove the Submittals. Should this proposed action be finalized, the version of Alabama's visible emissions rule that was approved in the SIP prior to EPA's October 15, 2008, final action will be the “current” SIP-approved rule.

Under Executive Order 12866 (58 FR 51735, October 4, 1993), this proposed action is not a significant regulatory action and is therefore not subject to Office of Management and Budget review.

This proposed action does not impose any new information collection burden under the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq., and therefore is not subject to these requirements.

The Regulatory Flexibility Act 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. Small entities include small businesses, small not-for-profit enterprises, and small governmental jurisdictions.

This proposed rule will not have a significant impact on a substantial number of small entities because SIP disapprovals under section 110 of the CAA do not create any new requirements. Therefore, because the Federal SIP disapproval does not create any new requirements, I certify that this action will not have a significant economic impact on a substantial number of small entities. Moreover, due to the nature of the Federal-State relationship under the CAA, preparation of flexibility analysis would constitute Federal inquiry into the economic reasonableness of state action. The CAA forbids EPA to base its actions concerning SIPs on such grounds. Union Electric Co., v. U.S. EPA, 427 US 246, 255-66 (1976); 42 U.S.C. 7410(a)(2).

Under sections 202 of the Unfunded Mandates Reform Act of 1995 (Unfunded Mandates Act), signed into law on March 22, 1995, EPA must prepare a budgetary impact statement to accompany any proposed or final rule that includes a Federal mandate that may result in estimated costs to State, local, or tribal governments in the aggregate; or to the private sector, of $100 million or more. Under section 205, EPA must select the most cost-effective and least burdensome alternative that achieves the objectives of the rule and is consistent with statutory requirements. Section 203 requires EPA to establish a plan for informing and advising any small governments that may be significantly or uniquely impacted by the rule.

EPA has determined that the disapproval action proposed does not include a Federal mandate that may result in estimated costs of $100 million or more to either state, local, or tribal governments in the aggregate, or to the private sector. This Federal action proposes to disapprove pre-existing requirements under State or local law, and imposes no new requirements. Accordingly, no additional costs to State, local, or tribal governments, or to the private sector, result from this action.

Federalism (64 FR 43255, August 10, 1999) revokes and replaces Executive Orders 12612 (Federalism) and 12875 (Enhancing the Intergovernmental Partnership). Executive Order 13132 requires EPA to develop an accountable process to ensure “meaningful and timely input by State and local officials in the development of regulatory policies that have federalism implications.” “Policies that have federalism implications” is defined in the Executive Order to include regulations that have “substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.” Under Executive Order 13132, EPA may not issue a regulation that has federalism implications, that imposes substantial direct compliance costs, and that is not required by statute, unless the Federal government provides the funds necessary to pay the direct compliance costs incurred by state and local governments, or EPA consults with state and local officials early in the process of developing the proposed regulation. EPA also may not issue a regulation that has federalism implications and that preempts state law unless the Agency consults with state and local officials early in the process of developing the proposed regulation.

This proposed rule will not have substantial direct effects on the states, on the relationship between the national government and the states, or on the distribution of power and responsibilities among the various levels of government, as specified in Executive Order 13132, because it merely proposes to disapprove a state rule implementing a federal standard, and does not alter the relationship or the distribution of power and responsibilities established in the CAA. Thus, the requirements of section 6 of the Executive Order do not apply to this rule.

Executive Order 13175, entitled “Consultation and Coordination with Indian Tribal Governments” (65 FR 67249, November 9, 2000), requires EPA to develop an accountable process to ensure “meaningful and timely input by tribal officials in the development of regulatory policies that have tribal implications.” This proposed rule does not have tribal implications, as specified in Executive Order 13175. This proposed rule will not have substantial direct effects on tribal governments, on the relationship between the Federal government and Indian tribes, or on the distribution of power and responsibilities between the Federal government and Indian tribes. Thus, Executive Order 13175 does not apply to this rule.

Protection of Children from Environmental Health Risks and Safety Risks (62 FR 19885, April 23, 1997), applies to any rule that: (1) is determined to be “economically significant” as defined under Executive Order 12866, and (2) concerns an environmental health or safety risk that EPA has reason to believe may have a disproportionate effect on children. If the regulatory action meets both criteria, the Agency must evaluate the environmental health or safety effects of the planned rule on children, and explain why the planned regulation is preferable to other potentially effective and reasonably feasible alternatives considered by the Agency.

This proposed rule is not subject to Executive Order 13045 because it does not involve decisions intended to mitigate environmental health or safety risks.

This proposed rule is not subject to Executive Order 13211, “Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use” (66 FR 28355, May 22, 2001) because it is not a significant regulatory action under Executive Order 12866.

Section 12 of the National Technology Transfer and Advancement Act (NTTAA) of 1995 requires Federal agencies to evaluate existing technical standards when developing a new regulation. To comply with NTTAA, EPA must consider and use “voluntary consensus standards” (VCS) if available and applicable when developing programs and policies unless doing so would be inconsistent with applicable law or otherwise impractical.

EPA believes that VCS are inapplicable to this action. Today's action does not require the public to perform activities conducive to the use of VCS.

Information Requested

We intend any final action resulting from this proposal to 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 other governmental agencies, tribes, the scientific community, industry, or other interested parties concerning this proposed rule. We particularly seek comments concerning:

(1) Biological information on Modoc sucker, including additional information on its distribution, population size, and population trend;

(2) Relevant information concerning any current or likely future threats (or lack thereof) to Modoc sucker, including the extent and adequacy of Federal and State protection and management that would be provided to Modoc sucker as a delisted species;

(3) Current or planned activities within the range of Modoc sucker and their possible impacts to the species;

(4) Regional climate change models and whether they are reliable and credible to use in assessing the effects of climate change on Modoc sucker and its habitat;

(5) Our draft post-delisting monitoring plan. We request information regarding how best to conduct post-delisting monitoring, should the proposed delisting lead to a final delisting rule (see Post-Delisting Monitoring Plan Overview section below, which briefly outlines the goals of the draft plan that is available for public comment concurrent with publication of this proposed rule). Such information might include suggestions regarding the monitoring focus, procedures for determining site occupancy and abundance, or for monitoring threats and recruitment over the course of at least 5 years.

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, will not be considered in making a determination, as section 4(b)(1)(A) of the Act directs that determinations as to whether any species is an endangered or 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 http://www.regulations.gov, your entire submission—including any personal identifying information—will be posted on the Web site. 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 http://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 http://www.regulations.gov, or by appointment, during normal business hours, at the U.S. Fish and Wildlife Service, Klamath Falls Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT ).

Section 4(b)(5) of the Act provides for one or more public hearings on this proposal, if requested. We must receive your request within 45 days after the date of this Federal Register publication. Send your request to the address shown in FOR FURTHER INFORMATION CONTACT . We will schedule public hearings on this proposal, if any are requested, and announce the dates, times, and places of those hearings, as well as how to obtain reasonable accommodations, in the Federal Register and local newspapers at least 15 days before the hearing.

On January 31, 1984, we proposed to list the Modoc sucker as an endangered species and designate critical habitat under the Act based on threats from habitat degradation and loss due to activities (such as overgrazing by cattle) that cause erosion and siltation (49 FR 3892). These activities and resulting erosion were thought to have eliminated natural barriers separating Modoc suckers and the Sacramento suckers ( Catostomus occidentalis ), allowing hybridization and a loss of genetic integrity of Modoc sucker. We published a final rule listing Modoc sucker as an endangered species and designating critical habitat in the Federal Register on June 11, 1985 (50 FR 24526). The final rule also included predation by the nonnative brown trout ( Salmo trutta ) as a threat to Modoc sucker.

Under the Act, we maintain the Lists of Endangered and Threatened Wildlife and Plants in title 50 of the Code of Federal Regulations (CFR) at 50 CFR 17.11 (for animals) and 17.12 (for plants) (Lists). We amend the Lists by publishing final rules in the Federal Register . Section 4(c)(2)(A) of the Act requires that we conduct a review of listed species at least once every 5 years. Section 4(c)(2)(B) requires that we determine: (1) Whether a species no longer meets the definition of endangered or threatened and should be removed from the Lists (delisted), (2) whether a species listed as endangered more properly meets the definition of threatened and should be reclassified to threatened (downlisted), or (3) whether a species listed as threatened more properly meets the definition of endangered and should be reclassified to endangered (uplisted). In accordance with 50 CFR 424.11(d), using the best scientific and commercial data available, we will consider a species for delisting only if the data substantiate that the species is neither endangered nor threatened for one or more of the following reasons: (1) The species is considered extinct; (2) the species is considered recovered; or (3) the original data available when the species was listed, or the interpretation of such data, were in error.

We published a notice announcing the initiation of a review of the status of Modoc sucker under section 4(c)(2) of the Act on March 22, 2006 (71 FR 14538). We notified the public of completion of the 5-year review on May 21, 2010 (75 FR 28636). The 5-year review, completed on August 17, 2009 (Service 2009), resulted in a recommendation to change the status of the species from endangered to threatened. A copy of the 2009 5-year review for Modoc sucker is available on the Service's Environmental Conservation Online System ( http://http://ecos.fws.gov/docs/five_year_review/doc2546.pdf ).

On December 21, 2011, we received a petition dated December 19, 2011, from the Pacific Legal Foundation, requesting the Service to reclassify the Modoc sucker from endangered to threatened. The petition was based on the analysis and recommendations contained in the most recent 5-year review. On June 4, 2012 (77 FR 32922), we published in the Federal Register a 90-day finding for the 2011 petition to reclassify the species. In our 90-day finding, we determined the 2011 petition provided substantial information indicating the petitioned actions may be warranted, and we initiated a status review for Modoc sucker. This proposed rule to remove the Modoc sucker from the Federal List of Endangered and Threatened Wildlife also constitutes the 12-month finding for the species.

A completed scientific analysis is presented in detail in the Modoc Sucker Species Report (Service 2013, entire), which is available at http://www.regulations.gov at Docket Number FWS-R8-ES-2013-0133. The Species Report was prepared by Service biologists to provide thorough discussion of the species ecology, biological needs, and analysis of the threats that may be impacting the species. The Species Report includes discussion of the following: Taxonomy and species description, habitat, biology, distribution and abundance, summary of factors affecting the species, and recovery. This detailed information is summarized in the following paragraphs of this Background section, the Recovery and Recovery Plan Implementation section, and the Summary of Factors Affecting the Species section.

The Modoc sucker is a small species of fish in the family Catostomidae. Individuals measure 2.8 to 3.3 inches (70 to 85 millimeters) in length at full maturity, with few adults exceeding 6.3 to 7.1 in (160 to 180 mm). Modoc suckers are opportunistic feeders with diets consisting of algae, small benthic invertebrates, and detritus.

Modoc sucker are primarily found in relatively small (second to fourth order), perennial and intermittent streams. They occupy an intermediate zone between the high-gradient and higher-elevation, coldwater trout zone and the low-gradient and low-elevation, warm-water fish zone. The pool habitat occupied by Modoc suckers generally includes fine sediments to small cobble bottoms, substantial detritus, and abundant cover. Spawning habitat appears to include gravel substrates in the relatively low-energy, flowing portions of pools or the protected area downstream of rocks (Reid 2008a). During low summer flows, pools inhabited by Modoc suckers can become isolated, which eliminates interaction of suckers within and among streams. Cover can be provided by overhanging banks, larger rocks, woody debris, and aquatic rooted vegetation or filamentous algae. Larvae occupy shallow vegetated margins; juveniles tend to remain free-swimming in the shallows of large pools, particularly near vegetated areas; and larger juveniles and adults remain mostly on, or close to, the bottom (Martin 1972; Moyle and Marciochi 1975; Moyle 2002).

At the time of listing, the species was known to occupy seven streams in the Turner Creek (Turner Creek, Washington Creek, and Hulbert Creek) and Ash Creek (Johnson Creek, Rush Creek, Dutch Flat Creek, and Ash Creek) sub-basins of the Pit River drainage in northeastern California. However, three of those streams (Rush Creek, Dutch Flat Creek, and Ash Creek) and a fourth (Willow Creek) in the Ash Creek sub-basin were presumed lost due to hybridization with Sacramento suckers ( Catostomus occidentalis ). It is now recognized that the historical distribution also included one additional stream (Garden Gulch Creek) in the Turner Creek sub-basin and three additional streams in the Goose Lake sub-basin (Thomas Creek, an unnamed tributary to Thomas Creek, and Cox Creek) in southern Oregon, a disjoined, upstream sub-basin of the Pit River. Also, a population has been established in Coffee Mill Creek in the Turner Creek sub-basin—a stream not known to have been occupied at the time of listing—as a result of California Department of Fish and Wildlife transplanting efforts.

The current known distribution of Modoc sucker includes an estimated 42.5 miles (68.4 kilometers) of occupied habitat in 12 streams within 3 sub-basins, compared to an estimated distribution of 12.9 miles (20.8 kilometers) of occupied habitat in 7 seven streams within 2 sub-basins at the time of listing. Although population trend data is not available because survey methods have varied among years, surveys indicate that Modoc sucker populations still occur in all streams where Modoc sucker populations were known to occur historically. Surveys also indicate that Modoc suckers appear to occupy nearly all available suitable habitat within the streams where they occur in the Turner Creek, Ash Creek, and Goose Lake sub-basins. Land ownership throughout the species' range is 51 percent public lands (primarily the Modoc National Forest in northeastern California and the Fremont-Winema National Forests in southern Oregon), 48 percent private lands, and 1 percent State land.

For a detailed discussion of Modoc sucker taxonomy and species description, habitat, biology, and distribution and abundance, please see the “Background” section of the Species Report, which includes subsections on “taxonomy and species description”, “habitat”, “biology”, and “distribution and abundance” (Service 2013, pp. 5-23).

Section 4(f) of the Act directs us to develop and implement recovery plans for the conservation and survival of endangered and threatened species unless we determine that such a plan will not promote the conservation of the species. Under section 4(f)(1)(B)(ii), recovery plans must, to the maximum extent practicable, include: “Objective, measurable criteria which, when met, would result in a determination, in accordance with the provisions of [section 4 of the Act], that the species be removed from the list.” However, revisions to the list (adding, removing, or reclassifying a species) must reflect determinations made in accordance with sections 4(a)(1) and 4(b) of the Act. Section 4(a)(1) requires that the Secretary determine whether a species is endangered or threatened (or not) because of one or more of five threat 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 human-made factors affecting its continued existence. Section 4(b) of the Act requires that the determination be made “solely on the basis of the best scientific and commercial data available.” Therefore, recovery criteria should indicate when a species is no longer an endangered species or threatened species under the five statutory factors.

Thus, while recovery plans provide important guidance to the Service, States, and other partners on methods of minimizing threats to listed species and measurable objectives against which to measure progress towards recovery, they are not regulatory documents and cannot substitute for the determinations and promulgation of regulations required under section 4(a)(1) of the Act. A decision to revise the status of or remove a species from the Federal List of Endangered and Threatened Plants (50 CFR 17.12) is ultimately based on an analysis of the best scientific and commercial data then available to determine whether a species is no longer an endangered species or a threatened species, regardless of whether that information differs from the recovery plan.

At the time of listing, the Service, the California Department of Fish and Wildlife (CDFW), and the U.S. Forest Service (USFS) were developing an “Action Plan for the Recovery of the Modoc sucker” (Action Plan). The April 27, 1983, revision of this Action Plan was formally signed by all participants in 1984 (Service 1984). We determined that the Action Plan and its 1989 revisions (Service 1984, 1989) adequately fulfilled the requirements of a recovery plan, and in a 1992 memorandum from the Regional Director (Region 1) to the Service's Director, we adopted it as the Recovery Plan for the Modoc sucker (Service 1992) and determined we would not prepare a separate recovery plan pursuant to section 4(f) of the Act.

The Recovery Plan included downlisting and delisting objectives (considered to be equivalent to criteria). Below, we outline the objectives to reclassify the Modoc sucker from endangered to threatened and the objectives to remove Modoc sucker from the List of Endangered and Threatened Wildlife, and we discuss progress towards meeting the objectives.

Downlisting objective 1: Maintain the integrity of extant habitats and prevent the invasion of Sacramento suckers into isolated stream reaches of the Turner-Hulbert-Washington Creek system and upper Johnson Creek. The intent of meeting this objective was to halt the threat of further loss and degradation of habitat (Factor A) and to address the threat of genetic introgression from hybridization with Sacramento sucker (Factor E).

Downlisting objective 2: Restore and maintain the quality of aquatic habitat conditions within these watersheds and thereby increase their carrying capacity for Modoc suckers. The intent of this objective was to further address habitat loss and degradation (Factor A) through active restoration, with the ultimate goal to allow the habitat to support an increase in population numbers. These efforts would improve the resiliency of the species (ability to withstand and recover from stochastic events, such as drought).

Downlisting objective 3: Secure populations of Modoc sucker have been maintained in these creeks for 3 consecutive years. The intent of this objective was to monitor Modoc sucker populations to ensure recruitment had occurred and is based on the life history of Modoc suckers, in which individuals mature at age 2+ years.

Since the time of listing, actions have been taken to maintain or improve Modoc sucker habitat within Turner Creek, Hulbert Creek, Washington Creek, and Johnson Creek as it relates to downlisting objectives 1 and 2. The Service and partners have implemented projects and management that maintain the integrity of extant habitat (downlisting objective 1) and restore and maintain the quality of habitat (downlisting objective 2) to provide effective stabilization of stream banks, fencing to exclude livestock grazing in riparian areas, restoration of riparian vegetation, and increased instream habitat. On public lands, 1.5 miles of Washington Creek, 0.2 mi of Hulbert Creek, 0.5 mi of Coffee Mill Creek, and approximately 1.5 mi of Turner Creek have been fenced to protect riparian habitat (Reid 2008a, p. 85; M. Yamagiwa, USFS, personal communication). Additionally, since Modoc sucker was listed in 1985, fencing has been constructed to exclude cattle on Rush Creek and Johnson Creek below Higgins Flat (Modoc National Forest). Fencing led to immediately protecting extant habitat (immediate, near term), and allowed habitat to recover. This improved the quality and carrying capacity in the long term, thus addressing downlisting objectives 1 and 2. Extensive landowner outreach by the Service, USFS, and State agencies, and improved livestock grazing management practices in Modoc and Lassen Counties have also resulted in improved protection of riparian corridors on private lands in the Turner and Ash Creek sub-basins. Protection of riparian habitat by excluding cattle and by improving livestock grazing management practices on both public and private lands has resulted in improved habitat conditions along these streams as a result of reduced erosion and improved vegetative and hydrologic characteristics (Reid 2008a, pp. 41, 85-86).

Active habitat restoration (downlisting objective 2) has been implemented in many locations throughout the species range since the species was listed. Restoration on the Modoc National Forest has led to improved habitat conditions in riparian areas along many of the streams occupied by Modoc suckers. Willows have been planted along portions of streams occupied by Modoc suckers in the Turner Creek and Ash Creek sub-basins to stabilize streambanks and provide shading and cover (Reid 2008a, pp. 85-86; USFS 2008, p. 16). As a result of riparian habitat improvements and improved livestock grazing management practices, channel widths have narrowed and created deeper habitat preferred by Modoc suckers (USFS 2008, p. 16). Other habitat restoration activities include juniper revetment (the use of cut juniper trees to stabilize streambanks), creation and expansion of pool habitat, placement of boulders within streams to provide cover and shade, and restoration of channel headcuts (areas of deep erosion) to prevent further downcutting of channels (Reid 2008a, pp. 85-86; USFS 2008, p. 16).

Habitat conditions in designated critical habitat and other occupied streams have steadily improved since listing and have sustained populations of Modoc suckers for at least 25 years, although recent habitat surveys indicate erosion and sedimentation continue to be a problem along lower Turner Creek. However, this degraded reach amounts to 2.4 percent (1.01 mi/42.5 mi) of the total length of streams occupied by Modoc sucker. Land management practices employed on public and private lands since the early 1980s are expected to continue, or improve, thereby maintaining stable to upward habitat trends. Thus, we believe the integrity of extant habitat has been maintained (part of downlisting objective 1) and the quality of habitat has been restored and maintained through restoration efforts (downlisting objective 2), and we conclude that these portions of the downlisting objectives have been met.

While part of downlisting objective 1 was to prevent invasion of Sacramento sucker, further research into the magnitude and consequences of genetic introgression with Sacramento suckers has led us to conclude that this part of the objective is no longer relevant. Observed levels of genetic introgression by Sacramento suckers in streams dominated by Modoc suckers are low, even when there are no physical barriers between the two species (Topinka 2006, pp. 64-65). This suggests that either ecological differences, selective pressures, or other natural reproductive-isolating mechanisms are sufficient to maintain the integrity of the species, even after more than a century of habitat alteration by human activities. Currently, only Ash Creek exhibits a considerable degree of introgression. Scientists who have studied suckers in western North America consider that, throughout their evolutionary history, hybridization among sympatric native fishes is not unusual and may actually provide an adaptive advantage (Dowling and Secor 1997, pp. 612-613; Dowling 2005, p. 10; Topinka 2006, p. 73; Tranah and May 2006, p. 313). Reexamination of information on natural barriers, morphological characters, and new genetic information that were unavailable at the time of listing indicate that hybridization is not a threat to the Modoc sucker and may be part of its natural evolutionary history. Thus, because of the new information that has become available since the time of listing, we believe this portion of the downlisting criterion, to prevent the invasion of Sacramento suckers, is obsolete and no longer needs to be met.

Several estimates of population size of Modoc suckers in Turner Creek, Hulbert Creek, Washington Creek, and Johnson Creek have been completed since the 1970s, which found that Modoc sucker populations have been maintained in the Turner-Hulbert-Washington Creek system and upper Johnson Creek for 3 consecutive years (downlisting objective 3). Modoc suckers appear broadly distributed throughout suitable habitat in these streams. Although the observations during each survey may not be directly comparable due to differences in sampling methods, there does not appear to be any major changes in observations of these stream populations over time. Observations of Modoc suckers in Hulbert Creek and Johnson Creek prior to 2008 appear to be greater than observations made in 2008 and 2012. However, this may be explained by differences in survey methods, inclusion of young-of-the-year suckers in earlier counts, and the fact that some numbers reported are population estimates rather than counts on individuals. Although population monitoring has not been conducted on an annual basis, sucker surveys conducted in 2008 and 2012 show that Modoc sucker populations have been maintained, and are still well established, in Turner Creek, Washington Creek, Hulbert Creek, and Johnson Creek—as well as each of the other streams known to be occupied at the time of listing—more than 25 years after listing. Thus, we believe that populations of Modoc sucker have been maintained (remained stable), demonstrating successful recruitment given that individuals mature at 2+ years, and that downlisting objective 3 has been met.

Delisting objective 1: The remaining suitable, but presently unoccupied, stream reaches within Turner-Hulbert Creek-Washington Creek and Rush-Johnson Creek drainages must be renovated and restored to Modoc sucker. The intent of this objective was to further address habitat loss and degradation (Factor A) through active restoration. Once occupied, these stream reaches would demonstrate that the habitat is restored and has expanded. This restoration will allow the habitat to support an increase in population numbers, improving redundancy (having multiple populations that provide security from the risk of extinction of the spices given the low probability that all populations will be negatively affected by a single catastrophic event) and resiliency (ability to withstand and recover from stochastic events, such as drought) of the species.

Delisting objective 2: Secure populations of Modoc suckers must be reestablished in at least two other streams outside of the above drainages, but within the historical range. The intent of this objective was to increase both habitat available and the number of populations, thereby increasing redundancy of the Modoc sucker populations.

Delisting objective 3: All populations must have sustained themselves through a climactic cycle that includes drought and flood events. This objective was intended to indicate that Modoc suckers have responded positively to habitat protection and restoration and have a sufficient number of populations and individuals to withstand and recover from environmental variability and stochastic events.

At the time of listing, it was estimated that Modoc suckers occupied 2.0 mi (3.2 km) of habitat in Turner Creek, 0.8 mi (1.3 km) of habitat in Hulbert Creek, 0.5 mi (0.8 km) of habitat in Washington Creek, 4.6 mi (7.4 km) in Rush Creek, and 1.2 mi (1.9 km) of habitat in Johnson Creek (Reid 2008a, p. 25). Since the time of listing, Reid (2008a, p. 25) estimated that there was 5.5 mi (8.9 km) of available habitat in Turner Creek, 3.0 mi (4.8 km) in Hulbert Creek, 4.1 mi (6.6 km) in Washington Creek, 4.6 mi (7.4 km) in Rush Creek, and 2.7 mi (4.3 km) in Johnson Creek. Habitat conditions along Turner Creek, Hulbert Creek, Washington Creek, and Johnson Creek have improved since the time of listing. Modoc suckers currently occupy all available habitats within Turner Creek, Hulbert Creek, Rush Creek, and Johnson Creek; Modoc suckers occupy 3.4 mi (5.5 km) of the available habitat in Washington Creek (Reid 2008a, p. 25). Therefore, we believe delisting objective 1 has been met.

The Recovery Plan stated that additional populations were needed to provide population redundancy (delisting objective 2). New information indicates the presence of Modoc sucker populations in four streams that were not known to be occupied at the time of listing (Garden Gulch Creek in the Turner Creek sub-basin and Thomas Creek, an unnamed tributary to Thomas Creek, and Cox Creek in the Goose Lake sub-basin). In addition, a population of Modoc sucker has been established as a result of transplanting in Coffee Mill Creek in the Turner Creek sub-basin. In 1987, CDFW transplanted Modoc suckers from Washington Creek to Coffee Mill Creek to establish an additional population in the Turner Creek sub-basin (CDFW 1986, p. 11). Modoc suckers appear to be well established and relatively abundant; spawning adult and juvenile suckers have been consistently observed there during visual surveys (Reid 2009, p. 25). Therefore, we believe that the intent of delisting objective 2 has been met by the discovery of Modoc sucker populations in additional locations and the establishment of one population.

The northwestern corner of the Great Basin where the Modoc sucker occurs is naturally subject to extended droughts, during which even the larger water bodies such as Goose Lake have dried up (Laird 1971, pp. 57-58). Regional droughts have occurred every 10 to 20 years in the last century (Reid 2008, pp. 43-44). Collections of Modoc suckers from Rush Creek and Thomas Creek near the end of the “dustbowl” drought of the 1920s to 1930s (Hubbs 1934, p. 1; Reid 2008a, p. 79) indicate that the species was able to persist in those streams even through a prolonged and severe drought. Modoc suckers have persisted throughout the species' historical range since the time it was listed in 1985, even though the region has experienced several pronounced droughts as well as heavy-precipitation, high-water years (for example, 2011), indicating that the species is at least somewhat resilient to weather and hydrologic fluctuations. Therefore, we believe delisting objective 3 has been met.

The Recovery Plan was based on the best scientific and commercial information available at the time. In evaluating the extent to which recovery objectives have been met, we must also assess new information that has become available since the species was listed and the recovery action plan prepared. As noted above, research and new information since the time of listing and the recovery action plan indicate that hybridization and introgression with Sacramento sucker is not a substantial threat to Modoc suckers. Additionally, Modoc suckers were found occupying areas they were not known to occupy at the time of listing. This new information alters the extent to which the recovery objectives related to hybridization and establishing new populations need to be met. In the case of hybridization and genetic introgression, we found that objective no longer relevant given the lack of threat to the species. With regard to the objective to establish new populations, we found that the discovery of additional populations substantially met the intent of the objective to provide for population redundancy so that reestablishing two additional populations was no longer needed.

Additionally, we must assess whether a recovery plan adequately addresses all the factors affecting the species. The recovery objectives did not directly address predation by brown trout and other nonnative fish or the point at which that threat would be ameliorated, although actions were included. Since the time of listing, additional predatory nonnative fish have been recorded in streams containing Modoc suckers. Actions to address nonnative predatory species and an assessment of their impact are discussed below. While not specific to predatory nonnative fish, attainment of delisting objective 3, indicating that Modoc sucker populations have sustained themselves since listing in 1985, provides some indication that nonnative predatory fish are no longer a serious threat to the species' persistence. Climate change is an additional threat identified since listing and preparation of the Recovery Plan. All threats, including those identified since listing and preparation of the Recovery Plan are further discussed below. Based on our analysis of the best available information, we conclude that the downlisting and delisting objectives have been substantially met. Additional threats not directly addressed in the recovery objectives are discussed below. Additional information on recovery and recovery plan implementation are described in the “Recovery” section of the Species Report (Service 2013, pp. 58-65).

Section 4 of the Act and its implementing regulations (50 CFR part 424) set forth the procedures for listing species, reclassifying species, or removing species from listed status. “Species” is defined by the Act as including any species or subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature (16 U.S.C. 1532(16)). A species may be determined to be an endangered or threatened species because of any one or a combination of the five factors described in section 4(a)(1) of the Act: (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 human-made factors affecting its continued existence. A species may be reclassified on the same basis.

A recovered species is one that no longer meets the Act's definition of threatened or endangered. Determining whether a species is recovered requires consideration of whether the species is endangered or threatened because of the same five categories of threats specified in section 4(a)(1) of the Act. For species that are already listed as endangered or threatened, this analysis of threats is an evaluation of both the threats currently facing the species and the threats that are reasonably likely to affect the species in the foreseeable future following the delisting or downlisting and the removal or reduction of the Act's protections.

A species is an “endangered species” for purposes of the Act if it is in danger of extinction throughout all or a significant portion of its range and is a “threatened species” if it is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range. The Act does not define the term “foreseeable future.” For the purposes of this rule, we define the “foreseeable future” to be the extent to which, given the amount and substance of available data, we can anticipate events or effects, or reliably extrapolate threat trends, such that we reasonably believe that reliable predictions can be made concerning the future as it relates to the status of Modoc sucker. Specifically, for Modoc sucker, we consider two factors: the management of threats and the response of the species to management. First, as described below, the threats to the species have been successfully ameliorated, largely due to management plans that are currently in place and expected to stay in place, and that are expected to successfully continue to control potential threats (USFS 1989, entire; USFS 1991, entire). Management plans that consider natural resources are required by law for all Federal lands on which Modoc sucker occurs, which encompasses greater than 50 percent of the species' range. Management plans are required to be in effect at all times and to be in compliance with various Federal regulations. Efforts to promote conservation of Modoc sucker habitat on private lands have been successful and are expected to continue into the future. Second, the Modoc sucker has demonstrated a quick positive response to management over the past 28 years since the species was listed; based on this, we anticipate being able to detect a species response to any changes in the management that may occur because of a plan amendment. Therefore, in consideration of Modoc sucker's positive response to management and our partners' commitment to continued management, as we describe below, we do not foresee that management practices will change and we anticipate that threats to the Modoc sucker will remain ameliorated into the foreseeable future. The word “range” in the significant portion of its range phrase refers to the range in which the species currently exists. For the purposes of this analysis, we first evaluate the status of the species throughout all its range, then consider whether the species is in danger of extinction or likely to become so in any significant portion of its range.

At the time of listing, the primary threats to Modoc sucker were threats from habitat degradation and loss due to activities (such as overgrazing by cattle) that cause erosion and siltation, and eliminated natural barriers that resulted in loss of genetic integrity of the species due to hybridization with Sacramento suckers ( Catostomus occidentalis ). Predation by the nonnative brown trout ( Salmo trutta ) was also identified as a threat to Modoc sucker.

A thorough analysis and discussion of the current status review initiated with our 2012 90-day finding (77 FR 32922) is detailed in the Species Report (Service 2013, entire). The following sections provide a summary of the past, current, and potential future threats impacting the Modoc sucker. These threats include activities (such as overgrazing) that cause erosion and siltation (Factor A); elimination of natural barriers (Factor A); climate change and drought (Factor A); predation by nonnative species (Factors C); and hybridization and genetic introgression (infiltration of genes of another species) (Factor E).

The listing rule stated that activities (such as overgrazing) that cause a reduction in riparian vegetation, which then leads to stream erosion, siltation, and incision were a threat to the species. An increase in silt from eroding banks may fill in the preferred pool habitat of Modoc suckers and can cover gravel substrate used for spawning (50 FR 24526, June 11, 1985; Moyle 2002, p. 190). Sediment introduced into streams can adversely affect fish populations by inducing embryo mortality, affecting primary productivity, and reducing available habitat for macroinvertebrates that Modoc suckers feed upon (Moyle 2002, p. 191). However, land and resource management, as guided through regulations and policies, can effectively reduce or control threats to Modoc sucker.

The National Forest Management Act (NFMA) and regulations and policies implementing the NFMA are the main regulatory mechanisms that guide land management on the Fremont-Winema and Modoc National Forests, which constitute about 51 percent of Modoc suckers' range. Since listing, the Fremont-Winema National Forests (USFS 1989, entire) and Modoc National Forest (USFS 1991, entire) have each included Modoc sucker and their habitat in their resource management plans. These plans are required by NFMA and the Federal Land Policy and Management Act of 1976 (FLPMA). The NFMA requires revision of the Plans every 15 years; however, plans may be amended or revised as needed. Management plans are required to be in effect at all times (in other words, if the revision does not occur, the previous plan remains in effect) and to be in compliance with various Federal regulations. The plans direct these national forests to maintain or increase the status of populations of federally endangered or threatened species and their habitats. In addition, these plans guide riparian management with a goal of restoring and maintaining aquatic and riparian ecosystems to their desired management potential (USFS 1989, Appendix p. 86; USFS 1991, pp. 4-26, Appendix pp. M-1-M-2).

Management direction for grazing on Forest-managed lands is provided through allotment management plans and permits, which stipulate various grazing strategies that will minimize adverse effects to the watershed and listed species. The allotment management plans outline grazing management goals that dictate rangeland management should maintain productive riparian habitat for threatened, endangered, and sensitive species (USFS 1995, p. 1). These grazing permits are valid for 10 years though operating instructions for these permits are issued on an annual basis. Also, as Federal agencies, the Fremont-Winema and Modoc National Forests comply with the National Environmental Policy Act process when evaluating potential land-disturbing projects or changes in National Forest management.

Although State lands comprise only 1 percent of Modoc suckers' range, both California and Oregon provide habitat protection. In California on State lands, the California Fish and Game Code affords protection to stream habitats for all perennial, intermittent, and ephemeral rivers and streams. In Oregon, the Oregon Department of Land Conservation and Development requires local land use planning ordinances to protect natural resources, including riparian and wetland habitats.

The improved livestock grazing management practices in these management plans have greatly reduced impacts to Modoc sucker habitat from poor livestock grazing practices since the time of listing. Since listing, some of the Modoc sucker streams on public land have been fenced to exclude or actively manage livestock grazing for the benefit of Modoc sucker conservation (Reid 2008a, pp. 34-36, 85). Riparian fencing along occupied streams to exclude cattle during the past 25 years has resulted in continued improvements in riparian vegetative corridors, in-stream cover, and channel morphology.

In 2012, the Klamath Falls Fish and Wildlife Office completed habitat surveys in Washington Creek, Garden Gulch Creek, Coffee Mill Creek, Dutch Flat Creek, Turner Creek, Hulbert Creek, and Johnson Creek within the Ash Creek and Turner Creek sub-basins. Data collected indicated that the average percent bank erosion was low (less than 40 percent) at Garden Gulch Creek, Coffee Mill Creek, Hulbert Creek, Washington Creek, and Johnson Creek. Bank erosion appeared moderate at the Dutch Flat Creek site (49 percent) and was highest at the Turner Creek site (75 percent). However, these two degraded reaches (Dutch Flat Creek and Turner Creek) combined amount to only 4.1 percent (1.76 mi/42.5 mi) of Modoc sucker's total occupied habitat. Bank erosion along these creeks has resulted in an introduction of silt, which can cover gravel substrate used for spawning by Modoc suckers (Moyle 2002, p. 191).

Land management practices employed on public and private lands since the early 1980s are expected to continue, or improve, thereby maintaining upward habitat trends as documented by survey data. On public lands, the resource management plans are required by NFMA and FLPMA and continue to be in effect until revised. Continued commitment to protection of resources, including Modoc sucker and riparian areas, in future revisions is expected. As an example, within the Fremont-Winema National Forest, Thomas Creek is a Priority Watershed under their Watershed Condition Framework, and the Forest is currently working on a watershed restoration action plan. The action plan will identify individual projects such as fish passage, instream restoration, and road treatments/closures. On State lands, the California Fish and Game Code affords protection to stream habitats for all perennial, intermittent, and ephemeral rivers and streams. The Oregon Department of Land Conservation and Development requires local land use planning ordinances to protect natural resources, including riparian and wetland habitats. However, there are no formalized agreements in place with private landowners that establish protection of Modoc sucker habitat, though continued outreach is expected to occur in the near future (e.g., through the Service's Partners for Fish and Wildlife Program).

Although the 2012 habitat surveys indicate that livestock grazing still results in stream bank erosion along streams occupied by Modoc suckers, these surveys and the 2008 and 2012 fish surveys indicate that livestock grazing management has improved greatly, and as a result of reduced impact to habitat, there has been no reduction in the distribution of Modoc suckers, and grazing results in erosion in only a small portion (4.1 percent) of the species' range. Management plans that consider natural resources are required by law for all Federal lands on which Modoc sucker occurs. Management plans are required to be in effect at all times (in other words, if the revision does not occur, the previous plan remains in effect) and to be in compliance with various Federal regulations. Further, several organizations have partnered with private landowners to complete habitat restoration on the private land parcels to benefit fish passage and riparian habitat. Therefore, based on the best available information and expectation that current management practices will continue into the future, we conclude that livestock grazing and erosion does not constitute a substantial threat to the Modoc sucker now and is not expected to in the future.

The listing rule assumed that natural passage barriers in streams occupied by Modoc suckers had been eliminated by human activities, allowing hybridization between the Modoc and Sacramento suckers (see Hybridization and Genetic Introgression below). The lack of barriers was also thought to provide exposure to nonnative predatory fishes (see Predation by Nonnative Species below). However, surveys completed since the time of listing reveal no evidence of historical natural barriers that would have acted as a physical barrier. This is particularly true during higher springtime flows when Sacramento suckers make their upstream spawning migrations (Moyle 2002, p. 187). The source of this misunderstanding appears to have been a purely conjectural discussion by Moyle and Marciochi (1975, p. 559) that was subsequently accepted without validation, and Moyle makes no mention of it in his most recent account of Modoc sucker status (Moyle 2002, pp. 190-191). Since our current understanding is that the elimination of passage barriers did not occur, we conclude that elimination of passage barriers was incorrectly identified as a threat and is not a threat to Modoc sucker.

The listing rule identified predation by nonnative brown trout as a threat to Modoc suckers (50 FR 24526, June 11, 1985). Since the time of listing, additional predatory nonnative fish species have been recorded in streams containing Modoc suckers (Service 2009): Largemouth bass, sunfish (green and bluegill), and brown bullheads. Two of the three known sub-basins with Modoc suckers contain introduced predatory fishes. The Ash Creek sub-basin contains brown trout and possibly largemouth bass in downstream reaches of Ash Creek. The Turner Creek sub-basin contains a number of warm-water predatory fish. The Goose Lake sub-basin does not contain any nonnative predatory fish.

The Ash Creek sub-basin contains brown trout, which have co-existed with Modoc suckers for over 70 years, but may suppress local native fish populations in small streams. There are no sources of largemouth bass upstream of Modoc sucker populations in the Ash Creek basin, although they may be present downstream in warmer, low-gradient reaches of Ash Creek proper. A substantial eradication effort in Johnson Creek, within the Ash Creek sub-basin, in 2009 and 2010 removed most brown trout from occupied Modoc sucker habitat (Reid 2010, p. 2).

The Turner Creek sub-basin contains largemouth bass, sunfish (green and bluegill), and brown bullheads, of which only the bass are considered a significant predator on Modoc suckers. Bass do not appear to reproduce or establish stable populations in Turner Creek because the creek's cool-water habitat is generally unsuitable for supporting largemouth bass populations. Since 2005, the Service has supported a successful program of active management for nonnative fishes in the Turner Creek basin, targeting bass and sunfishes with selective angling and hand removal methods that do not adversely impact native fish populations (Reid 2008b, p. 1).

Redband trout, the only native potential predator of Modoc sucker, also occupies upper Thomas Creek, but there are no nonnative fishes (Scheerer et al. 2010, pp. 278, 281). The upper reaches of Thomas Creek occupied by Modoc suckers are unlikely to be invaded by nonnative fishes given the lack of upstream source populations and presence of a natural waterfall barrier in the lowest reach.

While Modoc suckers may be negatively impacted by introduced predatory fishes, such as brown trout and largemouth bass, they have persisted in the presence of nonnative predators, and populations have remained relatively stable in the Ash Creek and Turner Creek sub-basins prior to and since the time of listing. The separation of the three known basins containing Modoc suckers further reduces the probability that a new or existing nonnative predator would impact all three basins simultaneously. In some instances, natural constraints limit the distribution of nonnative predators, such as cool-water habitat. In other cases, natural or manmade barriers limit potential introductions, as do policies and regulations within Oregon and California. State regulations and fish stocking policies, in both California and Oregon, prohibit transfer of fish from one water body to another. Regulations prohibiting transfer of fish between water bodies discourage the spread of predatory fish species such as brown trout and largemouth bass throughout the Modoc sucker's range. In addition, CDFW has discontinued stocking of the predatory brown trout into streams in the Pit River basin, and the Oregon Department of Fish and Wildlife (ODFW) does not stock brown trout in the Goose Lake sub-basin. Based on current policies and regulations, we do not expect additional predatory fish to be introduced into Modoc sucker habitat in the future. Therefore, based on the best available information, we conclude that introduced predators do not constitute a substantial threat to the Modoc sucker now or in the future.

Our analyses under the Endangered Species Act include consideration of ongoing and projected changes in climate. The terms “climate” and “climate change” are defined by the Intergovernmental Panel on Climate Change (IPCC). “Climate” refers to the mean and variability of different types of weather conditions over time, with 30 years being a typical period for such measurements, although shorter or longer periods also may be used (IPCC 2007, p. 78). The term “climate change” thus refers to a change in the mean or variability of one or more measures of climate (e.g., temperature or precipitation) that persists for an extended period, typically decades or longer, whether the change is due to natural variability, human activity, or both (IPCC 2007, p. 78). Various types of changes in climate can have direct or indirect effects on species. These effects may be positive, neutral, or negative and they may change over time, depending on the species and other relevant considerations, such as the effects of interactions of climate with other variables (e.g., habitat fragmentation) (IPCC 2007, pp. 8-14, 18-19). In our analyses, we use our expert judgment to weigh relevant information, including uncertainty, in our consideration of various aspects of climate change.

The listing rule did not identify drought or climate change as threats to the continued existence of the Modoc sucker. However, the northwestern corner of the Great Basin is naturally subject to extended droughts, during which streams and even the larger water bodies such as Goose Lake have dried up (Laird 1971, pp. 57-58). Regional droughts have occurred every 10 to 20 years in the last century, and Goose Lake went dry as recently as 1992 and 2010 (Reid 2008a, pp. 43-44; R. Larson, KFFWO, personal communication). We have no records of how frequently Modoc sucker streams went dry. Some reaches of occupied streams have been observed to dry up (or flow goes subsurface through the gravel instead of over the surface) nearly every summer under current climatic conditions (Reid 2008, p. 42), indicating that headwater reaches did stop flowing. In extreme droughts, the suckers may have withdrawn to permanent main-stem streams, such as Rush, Ash, and Turner Creeks, and later recolonized the tributaries. Suckers also take refuge in natural spring-fed headwater reaches and in deeper, headwater pools that receive subsurface flow even when most of the stream channel is dry (Reid 2008, p. 43). Collections of Modoc suckers from Rush Creek and Thomas Creek near the end of the “dustbowl” drought (Hubbs 1934, p. 1; Reid 2008a, p. 79) and the continued persistence of Modoc suckers throughout its known range through substantial local drought years since 1985 demonstrate the resiliency of Modoc sucker populations to drought.

Human-induced climate change could exacerbate low-flow conditions in Modoc sucker habitat during future droughts. A warming trend in the mountains of western North America is expected to decrease snowpack, hasten spring runoff, reduce summer stream flows, and increase summer water temperatures (Poff et al. 2002, p. 11; Koopman et al. 2009, p. 3; PRBO Conservation Science 2011, p. 15). Lower flows as a result of smaller snowpack could reduce sucker habitat, which might adversely affect Modoc sucker reproduction and survival. Warmer water temperatures could lead to physiological stress and could also benefit nonnative fishes that prey on or compete with Modoc suckers. Increases in the number and size of forest fires could also result from climate change (Westerling et al. 2006, p. 940) and could adversely affect watershed function resulting in faster runoff, lower base flows during the summer and fall, and increased sedimentation rates. It is possible that lower flows may result in increased groundwater withdrawal for agricultural purposes and thus reduced water availability in certain stream reaches occupied by Modoc suckers. While these are all possible scenarios, we have no data on which to predict the likelihood or magnitude of these outcomes.

In summary, droughts may be a concern because they could likely constrict the amount of available habitat and reduce access to spawning habitat. However, the species has not declined in distribution since the time of listing in 1985, even though the region where it exists has experienced several pronounced droughts since listing when total annual precipitation was approximately half of the long-term average (Western Regional Climate Center, http://www.wrcc.dri.edu/cgi-bin/cliMONtpre.pl?ca0161, accessed 23 January 2013). And, although we cannot predict future climatic conditions accurately, the persistence of Modoc sucker across its range through the substantial droughts of the last century suggests that the species is resilient to drought and reduced water availability. Because we are unable at this time to predict how climate change will exacerbate the effects of drought within the Modoc sucker's range, we cannot make meaningful projections on how the species may react to climate change or how its habitat may be affected. Therefore, based on the best available information, we conclude that droughts and climate change, while likely affecting Modoc sucker populations, do not constitute substantial threats to Modoc sucker now and are not expected to in the future.

The listing rule identified hybridization with the Sacramento sucker as a threat to the Modoc sucker. Hybridization can be cause for concern in a species with restricted distribution, particularly when a closely related, nonnative species is introduced into its range, which can lead to loss of genetic integrity or even extinction (Rhymer and Simberloff 1996, p. 83). At the time of listing, it was assumed that hybridization between Modoc suckers and Sacramento suckers had been prevented in the past by the presence of natural physical barriers, but that the loss of these stream barriers was allowing interaction and hybridization between the two species (see Elimination of Natural Barriers above). However, the assumption that extensive hybridization was occurring was based solely on the two species occurring in the same streams, and the identification of a few specimens exhibiting what were thought to be intermediate morphological characters. At the time of listing in 1985, genetic and complete morphological information to assess this assumption was not available.

The morphological evidence for hybridization in the listing rule was based on a limited understanding of morphological variation in Modoc suckers and Sacramento suckers, derived from the small number of specimens available at that time. The actual number of specimens identified as apparent hybrids by earlier authors was very small, and many of these specimens came from streams without established Modoc sucker populations. Subsequent evaluation of variability in the two species was based on a larger number of specimens. It showed that the overlapping characteristics (primarily lateral line and dorsal ray counts) that had been interpreted by earlier authors as evidence of hybridization, are actually part of the natural meristic (involving counts of body parts such as fins and scales) range for the two species. As a result, this variability is no longer thought to be the result of genetic introgression between the two species (Kettratad 2001, pp. 52-53).

We initiated a study in 1999 to examine the genetics of suckers in the Pit River basin and determine the extent and role of hybridization between the Modoc and Sacramento suckers using both nuclear and mitochondrial genes (Palmerston et al. 2001, p. 2; Wagman and Markle 2000, p. 2; Dowling 2005, p. 3; Topinka 2006, p. 50). The two species are genetically similar, suggesting that they are relatively recently differentiated or have a history of introgression throughout their range that has obscured their differences (Dowling 2005, p. 9; Topinka 2006, p. 65). Although the available evidence cannot differentiate between the two hypotheses, the genetic similarity in all three sub-basins, including those populations shown to be free of introgression based on species-specific genetic markers (Topinka 2006, pp. 64-65), suggests that introgression has occurred on a broad temporal and geographic scale and is not a localized or recent phenomenon. Consequently, the genetic data suggest that introgression is natural and is not caused or measurably affected by human activities.

In a later study, Topinka (2006, p. 50) analyzed nuclear DNA from each of the two species and identified species-specific markers indicating low levels of introgression by Sacramento sucker alleles into most Modoc sucker populations. However, there was no evidence of first generation hybrids, and it is not clear whether introgression occurred due to local hybridization or through immigration by individual Modoc suckers carrying Sacramento alleles from other areas where hybridization had occurred.

Scientists who have studied suckers in western North America consider that, throughout their evolutionary history, hybridization among sympatric native fishes is not unusual and may provide an adaptive advantage (Dowling and Secor 1997, pp. 612-613; Dowling 2005, p. 10; Topinka 2006, p. 73; Tranah and May 2006, p. 313). Further, despite any hybridization that has occurred in the past, the Modoc sucker maintains its morphological and ecological distinctiveness, even in populations showing low levels of introgression, and is clearly distinguishable in its morphological characteristics from the Sacramento sucker (Kettratad 2001, p. 3). The low levels of observed introgression by Sacramento suckers in streams dominated by Modoc suckers, even when there are no physical barriers between the two species, suggests that either ecological differences, selective pressures, or other natural reproductive-isolating mechanisms are sufficient to maintain the integrity of the species, even after more than a century of habitat alteration by human activities. Therefore, given the levels of observed introgression in streams dominated by Modoc suckers, the lack of evidence of first-generation hybrids, the fact that Modoc suckers and Sacramento suckers are naturally sympatric, and the continued ecological and morphological integrity of Modoc sucker populations, we conclude that hybridization and genetic introgression do not constitute threats to the Modoc sucker now and are not expected to in the future.

Threats to the Modoc sucker that were considered in the 1985 listing rule have been reduced or ameliorated or are no longer considered to have been actual threats at the time of listing. Further, climate change and drought are not considered substantial threats. Habitat conditions on both public and private lands have benefited since the time of listing as a result of improved livestock grazing management practices and construction of fencing to exclude cattle from riparian areas on several of the streams occupied by Modoc suckers. We expect habitat conditions to remain stable or improve. Although recent habitat surveys indicate erosion continues to be a problem along lower Turner Creek and in Dutch Flat Creek, these areas represent 4.1 percent (1.76 mi/42.5 mi) of Modoc sucker's total occupied habitat. Habitat threats are addressed through multiple Federal and State regulations, including NFMA, California and Oregon State water regulations, and California Fish and Game Code. Therefore, these impacts are not considered a substantial threat to the species.

Modoc suckers have coexisted with brown trout for more than 70 years, and the overlap in distribution of largemouth bass and Modoc suckers is limited because bass are warm water fish that occur in lower-elevation reaches downstream of many of the reaches occupied by Modoc sucker, and reservoir outflows have been screened to reduce the risk of bass being flushed into streams occupied by Modoc sucker. Further, State regulations in both California and Oregon prohibit transfer of fish from one water body to another. Thus, introduced predators are not a significant risk to Modoc sucker populations. A greater understanding of the genetic relationships and natural gene flow between the Modoc suckers and Sacramento suckers has reduced concerns over hybridization between the two naturally sympatric species.

Although none of the factors discussed above is having a major impact on Modoc sucker, a combination of factors could potentially have a much greater effect. For example, effects of erosion on habitat resulting from poor livestock grazing management practices could worsen during periods of prolonged, severe drought when some water sources may dry up, resulting in greater pressure on the remaining available water sources, which would likely degrade Modoc sucker habitat. However, the impacts of livestock grazing on Modoc sucker habitat has been greatly reduced or eliminated by improved grazing management practices and management plans, which are not expected to change. Although the types, magnitude, or extent of cumulative impacts are difficult to predict, we are not aware of any combination of factors that has not already or would not be addressed through ongoing conservation measures. Based on this assessment of factors potentially impacting the species, we consider Modoc sucker to have no substantial threats now or in the future (see Summary of Factors Affecting the Species section of the Species Report (Service 2013, pp. 23-57).

An assessment of the need for a species' protection under the Act is based on whether a species is in danger of extinction or likely to become so 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. As required by section 4(a)(1) of the Act, we conducted a review of the status of this species and assessed the five factors to evaluate whether Modoc sucker is endangered or threatened throughout all of its range. We examined the best scientific and commercial information available regarding the past, present, and future threats faced by the species. We reviewed information presented in the 2011 petition, information available in our files and gathered through our 90-day finding in response to this petition, and other available published and unpublished information. We also consulted with species experts and land management staff with the USFS, CDFW, and ODFW, who are actively managing for the conservation of Modoc sucker.

In considering what factors might constitute threats, we must look beyond the mere exposure of the species to the factor to determine whether the exposure causes actual impacts to the species. If there is exposure to a factor, but no response, or only a positive response, that factor is not a threat. If there is exposure and the species responds negatively, the factor may be a threat and we then attempt to determine how significant the threat is. If the threat is significant, it may drive, or contribute to, the risk of extinction of the species such that the species warrants listing as endangered or threatened as those terms are defined by the Act. This determination does not necessarily require empirical proof of a threat. The combination of exposure and some corroborating evidence of how the species is likely impacted could suffice. The mere identification of factors that could impact a species negatively is not sufficient to compel a finding that listing is appropriate; we require evidence that these factors are operative threats that act on the species to the point that the species meets the definition of an endangered species or threatened species under the Act.

Significant impacts at the time of listing that could have resulted in the extirpation of all or parts of populations have been eliminated or reduced since listing. We conclude that the previously recognized impacts to Modoc sucker from the present or threatened destruction, modification, or curtailment of its habitat or range (specifically, erosion due to poor cattle grazing management) (Factor A); elimination of natural barriers (Factor A); predation by nonnative species (Factor C); and hybridization or genetic introgression (specifically, from Sacramento sucker) (Factor E) do not rise to a level of significance, such that the species is in danger of extinction now or in the foreseeable future.

As a result of the discovery of five populations not known at the time of listing and the documentation of the genetic integrity of populations considered in the 1985 listing rule to have been lost due to hybridization, the known range of the Modoc sucker has increased and it currently occupies its entire known historical range. Additionally, the distribution of occupied stream habitat for populations known at the time of listing has remained stable or expanded slightly since the time of listing, even though the region has experienced several droughts during this time period. Additionally, the relevant recovery objectives outlined in the Recovery Plan for the Modoc sucker have been met, indicating sustainable populations exist throughout the species' range. Finally, an assessment of factors that may be impacting the species did not reveal any significant threats to the species, now or in the future. We have carefully assessed the best scientific and commercial data available and determined that Modoc sucker is no longer in danger of extinction throughout all of its range, nor is it likely to become so in the future.

Having examined the status of Modoc sucker throughout all its range, we next examine whether the species is in danger of extinction in a significant portion of its range. The range of a species can theoretically be divided into portions in an infinite number of ways. However, there is no purpose in analyzing portions of the range that have no reasonable potential to be significant or in analyzing portions of the range in which there is no reasonable potential for the species to be endangered or threatened. To identify only those portions that warrant further consideration, we determine whether there is substantial information indicating that: (1) The portions may be “significant” and (2) the species may be in danger of extinction there or likely to become so within the foreseeable future. Depending on the biology of the species, its range, and the threats it faces, it might be more efficient for us to address the significance question first or the status question first. Thus, if we determine that a portion of the range is not “significant,” we do not need to determine whether the species is endangered or threatened there; if we determine that the species is not endangered or threatened in a portion of its range, we do not need to determine if that portion is “significant.” In practice, a key part of the determination that a species is in danger of extinction in a significant portion of its range is whether the threats are geographically concentrated in some way. If the threats to the species are essentially uniform throughout its range, no portion is likely to warrant further consideration. Moreover, if any concentration of threats to the species occurs only in portions of the species' range that clearly would not meet the biologically based definition of “significant,” such portions will not warrant further consideration.

We consider the “range” of Modoc sucker to include an estimated 42.5 miles (68.4 kilometers) of occupied habitat in 12 streams in the Turner Creek, Ash Creek, and Goose Lake sub-basins of the Pit River. This amount has improved greatly since the time of listing, when its known distribution was limited to an estimated 12.9 miles (20.8 kilometers) of occupied habitat in seven streams in the Turner Creek and Ash Creek sub-basins. This distribution represents its entire known historical range, with the exception of Willow Creek within the Ash Creek sub-basin. Previous reports of Modoc suckers in Willow Creek are based on limited and unverifiable reports (Reid 2009, p. 14), and their present existence in Willow Creek remains questionable (Reid 2008a, p. 25). Therefore, we consider the confirmed historical range to be occupied.

We considered whether any portions of the Modoc sucker range might be both significant and in danger of extinction or likely to become so in the foreseeable future. One way to identify portions would be to identify natural divisions within the range that might be of biological or conservation importance. Modoc sucker inhabit three sub-basins of the Pit River, one of which, the Goose Lake sub-basin, is disjoined from the other two sub-basins (Turner Creek and Ash Creek sub-basins). These sub-basins have the potential to be significant areas to the species due to potential geographic isolation. Although the sub-basins have the potential to be significant, the populations of the species within the sub-basins are not in danger of extinction or likely to become so within the foreseeable future due to lack of significant threats. Another way to identify portions would be to consider whether any threats are geographically concentrated in some way that would indicate the species could be threatened or endangered in that area. As noted above, erosion due to poor grazing management still occurs within approximately 4.1 percent of the Modoc sucker range, and has the potential to adversely affect Modoc sucker in those areas. These two sites are within different sub-basins and, both collectively and per sub-basin, represent a very small fraction of the Modoc sucker's range. These areas, individually or collectively, are therefore unlikely to constitute a significant portion of the species' range. No other natural divisions occur, and no other potential remaining threats have been identified. Therefore, it is our conclusion, based on our evaluation of the current and potential threats to Modoc sucker, that these threats are neither sufficiently concentrated nor of sufficient magnitude to indicate the species is in danger of extinction or likely to become so in the foreseeable future in any of the areas that support the species, and thus, it is likely to persist throughout its historical range.

We have carefully assessed the best scientific and commercial data available and determined that the Modoc sucker is no longer in danger of extinction throughout all or significant portions of its range, nor is it likely to become so in the future. As a consequence of this determination, we are proposing to remove this species from the list of endangered and threatened species under the Act.

If this proposed rule is made final, it would revise 50 CFR 17.11(h) to remove the Modoc sucker from the List of Endangered and Threatened Wildlife and would revise 50 CFR 17.95(e) to remove designated critical habitat for the species. The prohibitions and conservation measures provided by the Act, particularly through sections 7 and 9, would no longer apply to this species. Federal agencies would no longer be required to consult with the Service under section 7 of the Act in the event that activities they authorize, fund, or carry out may affect Modoc sucker.

In accordance with our joint policy on peer review published in the Federal Register on July 1, 1994 (50 FR 34270), we will seek the expert opinions of at least three appropriate and independent specialists regarding this proposed rule and the draft post-delisting monitoring (PDM) plan. A thorough review of information that we relied on in preparing this proposed rule—including information on taxonomy, life-history, ecology, population distribution and abundance, and potential threats—is presented in the Modoc Sucker Species Report (Service 2013) available at www.regulations.gov (Docket Number FWS-R8-ES-2013-0133). The purpose of peer review is to ensure that decisions are based on scientifically sound data, assumptions, and analyses. A peer review panel will conduct an assessment of the proposed rule, and the specific assumptions and conclusions regarding the proposed delisting. This assessment will be completed during the public comment period.

We will consider all comments and information we receive during the comment period on this proposed rule as we prepare the final determination. Accordingly, the final decision may differ from this proposal.

Section 4(g)(1) of the Act requires us, in cooperation with the States, to implement a monitoring program for not less than 5 years for all species that have been recovered and delisted (50 CFR 17.11, 17.12). The purpose of this post-delisting monitoring (PDM) is to verify that a species remains secure from risk of extinction after it has been removed from the protections of the Act. The PDM is designed to detect the failure of any delisted species to sustain itself without the protective measures provided by the Act. If, at any time during the monitoring period, data indicate that protective status under the Act should be reinstated, we can initiate listing procedures, including, if appropriate, emergency listing under section 4(b)(7) of the Act. Section 4(g) of the Act explicitly requires us to cooperate with the States in development and implementation of PDM programs, but we remain responsible for compliance with section 4(g) and, therefore, must remain actively engaged in all phases of PDM. We also seek active participation of other entities that are expected to assume responsibilities for the species' conservation post-delisting.

The Service has developed a draft PDM plan for the Modoc sucker. The PDM plan is designed to verify that Modoc sucker remains secure from risk of extinction after removal from the Federal List of Endangered and Threatened Wildlife by detecting changes in its status and habitat throughout its known range.

Although the Act has a minimum PDM requirement of 5 years, we will monitor Modoc sucker for a 10-year monitoring period to account for environmental variability (for example, drought) that may affect the condition of habitat and to provide for a sufficient number of surveys to document any changes in the abundance of the species. Based on the life history of Modoc suckers, in which individuals mature at age 2+ years, a complete survey of previously surveyed areas should be conducted every 2 years within the 10-year monitoring period. This will allow us to assess changes in abundance or the extent of the species' range over time; changes in the level of recruitment of reproducing fish into the population; and any potential changes in threats to the species. However, if a decline in abundance is observed or a substantial new threat arises, post-delisting monitoring may be extended or modified as described below.

A multi-state occupancy approach (MacKenzie et al. 2009, entire) will be used to estimate the proportion of sites occupied, change in site occupancy, and change in abundance of Modoc suckers. Surveys for Modoc suckers will be completed following a modified version of a sampling protocol developed for Modoc sucker (Reid 2008b) that is consistent with the approach used in surveys conducted since 2008. This approach will allow for monitoring population status over time as it permits the estimation of the proportion of sites (within a stream and among all streams) that are occupied and that are in each state of abundance (low and high). During occupancy and abundance surveys, we will also monitor threats and recruitment. To measure recruitment, we will estimate the size of individuals to the nearest centimeter. Examination of fish sizes will allow a determination to be made if recruitment is occurring over time. Ideally, surveys will result in diverse size classes of fish, indicating recruitment is occurring. Threats, both biotic (for example, nonnative predatory fish) and abiotic (for example, excessive sedimentation) will also be assessed during surveys (both day and night). Prior to completing surveys, sites (pools) within streams will be landmarked and georeferenced to allow relocation for subsequent surveys.

After each complete survey (conducted once every 2 years), the Service and its partners will compare the results with those from previous surveys and consider the implication of any observed reductions in abundance or threats to the species. Within 1 year of the end of the PDM period, the Service will conduct a final internal review and prepare (or contract with an outside entity) a final report summarizing the results of monitoring. This report will include: (1) A summary of the results from the surveys of Modoc sucker occupancy, states of abundance, recruitment, and change in distribution; and (2) recommendations for any actions and plans for the future. The final report will include a discussion of whether monitoring should continue beyond the 10-year period for any reason.

With this notice, we are soliciting public comments and peer review on the draft PDM Plan including its objectives and procedures (see Public Comments Solicited). All comments on the draft PDM plan from the public and peer reviewers will be considered and incorporated into the final PDM plan as appropriate. The draft PDM plan will be posted on our Endangered Species Program's national Web page ( http://endangered.fws.gov ) and the Klamath Falls Fish and Wildlife Office Web page ( http://fws.gov/klamathfallsfwo ) and on the Federal eRulemaking Portal at http://www.regulations.gov. We anticipate finalizing this plan, considering all public and peer review comments, prior to making a final determination on the proposed delisting rule.

We are required by Executive Orders 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:

(a) Be logically organized;

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

(c) Use clear language rather than jargon;

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

(e) 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 names 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.

We determined we do not need to prepare an Environmental Assessment or an Environmental Impact Statement, as defined under the authority of the National Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq. ), in connection with regulations adopted pursuant to section 4(a) of the Act. We published a notice outlining our reasons for this determination in the Federal Register on October 25, 1983 (48 FR 49244).

A complete list of all references cited in this proposed rule is available on the Internet at http://www.regulations.gov under Docket No. FWS-R8-ES-2013-0133 or upon request from the Field Supervisor, Klamath Falls Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT ).

The primary author of this proposed rule is the Pacific Southwest Regional Office in Sacramento, California, in coordination with the Klamath Falls Fish and Wildlife Office in Klamath Falls, Oregon (see FOR FURTHER INFORMATION CONTACT ).

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

We will accept written comments and information during this reopened comment period on our proposed designation of critical habitat for Ivesia webberi that was published in the Federal Register on August 2, 2013 (78 FR 46862), our DEA of the proposed designation, the amended required determinations provided in this document, and the revisions to five of the proposed units as described in this document. We will consider information and recommendations from all interested parties. We are particularly interested in comments concerning:

(1) The reasons why we should or should not designate habitat as “critical habitat” under section 4 of the Act (16 U.S.C. 1531 et seq. ), including whether there are threats to the species from human activity, the degree those threats can be expected to increase due to the designation, and whether that increase in threat outweighs the benefit of designation such that the designation of critical habitat is not prudent.

(2) Specific information on:

(a) The amount and distribution of Ivesia webberi habitat;

(b) The areas that are currently occupied and contain features essential to the conservation of the species that we should include in the designation and why;

(c) Special management considerations or protection that may be needed in critical habitat areas we are proposing, including managing for the potential effects of climate change; and

(d) The areas not occupied at the time of listing that are essential for the conservation of the species and why.

(3) Land use designations and current or planned activities in the subject areas and their probable impacts on proposed critical habitat.

(4) Any probable economic, national security, or other relevant impacts of designating any area that may be included in the final designation; in particular, we seek information on the benefits of including or excluding areas that exhibit these impacts.

(5) Information on the extent to which the description of economic impacts in the DEA is a reasonable estimate of the likely economic impacts.

(6) The likelihood of adverse social reactions to the designation of critical habitat, as discussed in the associated documents of the DEA, and how the consequences of such reactions, if likely to occur, would relate to the conservation and regulatory benefits of the proposed critical habitat designation.

(7) Whether any areas we are proposing for critical habitat designation should be considered for exclusion under section 4(b)(2) of the Act, and whether the benefits of potentially excluding any specific area outweigh the benefits of including that area under section 4(b)(2) of the Act.

(8) Whether we could improve or modify our approach to designating critical habitat in any way to provide for greater public participation and understanding, or to better accommodate public concerns and comments.

If you submitted comments or information on the proposed rule (78 FR 46862) during the initial comment period from August 2, 2013, to October 1, 2013, please do not resubmit them. We will incorporate them into the public record as part of this comment period, and we will fully consider them in the preparation of our final determination. Our final determination concerning critical habitat will take into consideration all written comments and any additional information we receive during both comment periods. Accordingly, the final decision may differ from the proposed rule, as revised by this document.

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

If you submit a comment via http://www.regulations.gov, your entire comment—including any personal identifying information—will be posted on the Web site. We will post all hardcopy comments on http://www.regulations.gov as well. If you submit a hardcopy comment 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.

Comments and materials we receive, as well as supporting documentation we used in preparing the proposed listing, proposed critical habitat, and DEA, will be available for public inspection on http://www.regulations.gov at Docket Number FWS-R8-ES-2013-0080, or by appointment, during normal business hours, at the U.S. Fish and Wildlife Service, Nevada Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT ). You may obtain copies of the proposed rule to designate critical habitat and the DEA on the Internet at http://www.regulations.gov at Docket Number FWS-R8-ES-2013-0080, or by mail from the Nevada Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT section).

It is our intent to discuss only those topics directly relevant to the proposed designation of critical habitat for Ivesia webberi (78 FR 46862) in this document. For more information on previous Federal actions concerning the I. webberi, refer to the proposed listing rule (78 FR 46889) that published in the Federal Register on August 2, 2013. Both proposed rules are available online at http://www.regulations.gov (at Docket No. FWS-R8-ES-2013-0079 for the proposed listing and Docket No. FWS-R8-ES-2013-0080 for the proposed critical habitat designation) or from the Nevada Fish and Wildlife Office (see FOR FURTHER INFORMATION CONTACT ).

On August 2, 2013, we published a proposed rule to designate critical habitat for Ivesia webberi (78 FR 46862). We proposed to designate approximately 2,011 acres (ac) (814 hectares (ha)) as critical habitat for I. webberi in Plumas, Lassen, and Sierra Counties in northeastern California and in Washoe and Douglas Counties in northwestern Nevada. That proposal had an initial 60-day comment period ending October 1, 2013. This document announces a proposed revision of the boundaries and acreages of five units (Units 9, 10, 12, 13, and 14) described in the August 2, 2013, proposed rule to designate critical habitat. We anticipate submitting for publication in the Federal Register a final critical habitat designation for I. webberi on or before August 2014, if we finalize our proposed rule to list the species under the Act.

Section 3 of the Act defines critical habitat as the specific areas within the geographical area occupied by a species, at the time it is listed in accordance with the Act, on which are found those physical or biological features essential to the conservation of the species and that may require special management considerations or protection, and specific areas outside the geographical area occupied by a species at the time it is listed, upon a determination that such areas are essential for the conservation of the species. If the proposed rule is made final, section 7 of the Act will prohibit destruction or adverse modification of critical habitat by any activity funded, authorized, or carried out by any Federal agency. Federal agencies proposing actions affecting critical habitat must consult with us on the effects of their proposed actions, under section 7(a)(2) of the Act.

On August 2, 2013, we proposed as critical habitat for Ivesia webberi 16 units (2 with subunits), consisting of approximately 2,011 ac (814 ha) in Plumas, Lassen, and Sierra Counties in northeastern California and in Washoe and Douglas Counties in northwestern Nevada (78 FR 46862).

We are now proposing to increase the designation by approximately 159 ac (65 ha) to a total of approximately 2,170 ac (879 ha). We propose this increase based on new information received from the U.S. Forest Service (Forest Service) that better defines the physical and biological features along the boundaries of these five proposed units, resulting in changes to the acreages for those units. The revised units include: Unit 9 (Stateline Road 1), Unit 10 (Stateline Road 2), Unit 12 (Black Springs), Unit 13 (Raleigh Heights), and Unit 14 (Dutch Louie Flat) (see Table 1). Apart from the acreages and ownership percentages provided in the unit descriptions in the August 2, 2013, proposed rule, the information in the unit descriptions in that proposal remains unchanged.

Section 4(b)(2) of the Act requires that we designate or revise critical habitat based upon the best scientific data available, after taking into consideration the economic impact, impact on national security, or any other relevant impact of specifying any particular area as critical habitat. We may exclude an area from critical habitat if we determine that the benefits of excluding the area outweigh the benefits of including the area as critical habitat, provided such exclusion will not result in the extinction of the species.

When considering the benefits of inclusion for an area, we consider among other factors, the additional regulatory benefits that an area would receive through the analysis under section 7 of the Act addressing the destruction or adverse modification of critical habitat as a result of actions with a Federal nexus (activities conducted, funded, permitted, or authorized by Federal agencies), the educational benefits of identifying areas containing essential features that aid in the recovery of the listed species, and any ancillary benefits triggered by existing local, State or Federal laws as a result of the critical habitat designation.

When considering the benefits of exclusion, we consider, among other things, whether exclusion of a specific area is likely to incentivize or result in conservation; the continuation, strengthening, or encouragement of partnerships; and the implementation of a management plan. In the case of Ivesia webberi, the benefits of critical habitat include public awareness of the presence of the species, the importance of habitat protection, and, where a Federal nexus exists, increased habitat protection for I. webberi. In practice, situations with a Federal nexus exist primarily on Federal lands or for projects undertaken by Federal agencies. We have not proposed to exclude any areas from critical habitat.

Section 4(b)(2) of the Act and its implementing regulations require that we consider the economic impact that may result from a designation of critical habitat. To assess the probable economic impacts of a designation, we must first evaluate specific land uses or activities and projects that may occur in the area of the critical habitat. We then must evaluate the impacts that a specific critical habitat designation may have on restricting or modifying specific land uses or activities for the benefit of the species and its habitat within the areas proposed. We then identify which conservation efforts may be the result of the species being listed under the Act versus those attributed solely to the designation of critical habitat for this particular species. The probable economic impact of a proposed critical habitat designation is analyzed by comparing scenarios “with critical habitat” and “without critical habitat.” The “without critical habitat” scenario represents the baseline for the analysis, which includes the existing regulatory and socio-economic burden imposed on landowners, managers, or other resource users potentially affected by the designation of critical habitat (e.g., under the Federal listing as well as other Federal, State, and local regulations). The baseline, therefore, represents the costs of all efforts attributable to the listing of the species under the Act (i.e., conservation of the species and its habitat incurred regardless of whether critical habitat is designated). The “with critical habitat” scenario describes the incremental impacts associated specifically with the designation of critical habitat for the species. The incremental conservation efforts and associated impacts would not be expected without the designation of critical habitat for the species. In other words, the incremental costs are those attributable solely to the designation of critical habitat, above and beyond the baseline costs. These are the costs we use when evaluating the benefits of inclusion and exclusion of particular areas from the final designation of critical habitat should we choose to conduct an optional 4(b)(2) exclusion analysis.

For this particular designation, we developed an incremental effects memorandum (IEM) considering the probable incremental economic impacts that may result from the proposed designation of critical habitat (Service 2013). The information contained in our IEM was then used to develop a screening analysis (Industrial Economics, Incorporated (IEc) 2013, 2014) of the probable effects of the designation of critical habitat for Ivesia webberi. We began by conducting a screening analysis of the proposed designation of critical habitat in order to focus our analysis on the key factors that are likely to result in incremental economic impacts. The purpose of the screening analysis is to filter out the geographic areas in which the critical habitat designation is unlikely to result in probable incremental economic impacts. In particular, the screening analysis considers baseline costs (i.e., absent critical habitat designation) and includes probable economic impacts where land and water use may be subject to conservation plans, land management plans, best management practices, or regulations that protect the habitat area as a result of the Federal listing status of the species. The screening analysis filters out particular areas of critical habitat that are already subject to such protections and are, therefore, unlikely to incur incremental economic impacts. Ultimately, the screening analysis allows us to focus our analysis on evaluating the specific areas or sectors that may incur probable incremental economic impacts as a result of the designation. This screening analysis (IEc 2013, 2014) combined with the information contained in our IEM (Service 2013) are what we consider our DEA of the proposed critical habitat designation for I. webberi, and the DEA is summarized in the narrative below.

Executive Orders (E.O.s) 12866 and 13563 direct Federal agencies to assess the costs and benefits of available regulatory alternatives in quantitative (to the extent feasible) and qualitative terms. Consistent with the E.O.s' regulatory analysis requirements, our effects analysis under the Act may take into consideration impacts to both directly and indirectly impacted entities, where practicable and reasonable. We assess, to the extent practicable, the probable impacts, if sufficient data are available, to both directly and indirectly impacted entities. As part of our screening analysis, we considered the types of economic activities that are likely to occur within the areas likely affected by the critical habitat designation. In our evaluation of the probable incremental economic impacts that may result from the proposed designation of critical habitat for Ivesia webberi, first we identified, in the IEM dated October 31, 2013, probable incremental economic impacts associated with the following categories of activities: (1) Federal lands management (Forest Service and U.S. Bureau of Land Management (BLM)); (2) commercial or residential development; (3) livestock grazing; (4) off-highway vehicle (OHV) and other recreational activities; (5) wildfire; (6) vegetation management, including fuels reduction activities and management for invasive species; and (7) vegetation or ground-disturbing activities associated with construction, maintenance or use of roads, trails, transmission lines, or other infrastructure corridors (Service 2013, pp. 3-10). We considered each industry or category individually. Additionally, we considered whether their activities have any Federal involvement.

Critical habitat designation will not affect activities that do not have any Federal involvement; designation of critical habitat only affects activities conducted, funded, permitted, or authorized by Federal agencies. In areas where Ivesia webberi is present, Federal agencies already are required to consult with the Service under section 7 of the Act on activities they fund, permit, or implement that may affect the species. If we finalize the proposed critical habitat designation, consultations to avoid the destruction or adverse modification of critical habitat would be incorporated into the existing consultation process. Therefore, disproportionate impacts to any geographic area or sector are not likely as a result of this critical habitat designation.

In our IEM, we attempted to clarify the distinction between the effects that will result from the species being listed and those attributable to the critical habitat designation (i.e., difference between the jeopardy and adverse modification standards) for Ivesia webberi' s critical habitat (Service 2013, pp. 12-22). Because the designation of critical habitat for I. webberi was proposed concurrently with the listing, it has been our experience that it is more difficult to discern which conservation efforts are attributable to the species being listed and those which will result solely from the designation of critical habitat. However, the following specific circumstances in this case help to inform our evaluation: (1) The essential physical and biological features identified for critical habitat are the same features essential for the life requisites of the species, and (2) any actions that would constitute jeopardy to I. webberi would also likely adversely affect the essential physical and biological features of critical habitat. The IEM outlines our rationale concerning this limited distinction between baseline conservation efforts and incremental impacts of the designation of critical habitat for this species (Service 2013, pp. 12-22). This evaluation of the incremental effects has been used as the basis to evaluate the probable incremental economic impacts of this proposed designation of critical habitat.

The proposed critical habitat designation for Ivesia webberi (as proposed on August 2, 2013 (78 FR 46862)) totals approximately 2,011 ac (814 ha), all of which are considered occupied by the species. Of the 2,011 ac (814 ha), approximately 68 percent of the total proposed designation is located on Federal lands, 11 percent on State land, and 21 percent on private lands. Additionally, 53 percent (or 1,072 ac (434 ha) of the 2,011 ac (814 ha)) are actively managed for I. webberi conservation through the Forest Service's Conservation Assessment and Strategy for Ivesia Webberi (Bergstrom 2009, entire). In this notice we are proposing revised unit boundaries and acreages for five units described in our August 2, 2013, proposal (78 FR 46862) based on comments we received on the proposal. These revisions, which were not available at the time the DEA was developed, result in an increase of approximately 159 ac (65 ha) in the proposed designation of critical habitat (see Table 1 above). After considering the economic impacts for the proposed areas and assessing the minimal changes to the boundaries of the proposed areas, we expect that economic impacts will not increase substantially. These changes will be fully analyzed and reported in the final economic analysis. As discussed above, the following economic activities are identified as having the potential to impact proposed critical habitat (as well as the additional 159 ac (65 ha) that we are proposing for the revised unit boundaries): Federal lands management (Forest Service and BLM); commercial or residential development; livestock grazing, off-highway vehicle use, and other recreational activities; wildfire; vegetation management, including fuels reduction activities and management for invasive species; and vegetation or ground-disturbing activities associated with construction, maintenance or use of roads, trails, transmission lines, or other infrastructure corridors.

Our DEA determined that the section 7-related costs of designating critical habitat for Ivesia webberi are likely to be limited to the additional administrative effort required to consider adverse modification in a small number of consultations. This finding is based on:

(1) All proposed units are considered occupied, providing baseline protection resulting from the listing of the species as threatened under the Act.

(2) Activities occurring within designated critical habitat with a potential to affect the species' habitat are also likely to adversely affect the species, either directly or indirectly.

(3) Project modifications requested to avoid adverse modification are likely to be the same as those needed to avoid jeopardy in occupied habitat.

(4) Federal agencies operating in proposed critical habitat areas are already aware of the presence of Ivesia webberi and also are experienced consulting with us under section 7 of the Act on other federally listed species. Thus, in the baseline, they are likely to consult even in buffer areas surrounding the species included in the designation to ensure protection of pollinator habitat.

The incremental administrative burden resulting from the designation is unlikely to reach $100 million in a given year based on the small number of anticipated consultations (i.e., less than two consultations per year) and per-consultation costs. Furthermore, it is unlikely that the designation of critical habitat will trigger additional requirements under State or local regulations. Costs resulting from public perception of the effect of critical habitat, if they occur, are unlikely to reach $100 million in a given year, based on the small number of acres possibly affected and average land values in the vicinity of those acres.

The results of our analysis also suggest approximately 114 ac (46 ha) of private, vacant land is available for future development in the proposed critical habitat area (specifically, the Reno/Sparks metropolitan area in Washoe County); however, we note that after our analysis was completed and based on comments during the first open comment period, our revised proposed critical habitat has resulted in a total of approximately 138 ac (55 ha) of private, vacant land that may be available for future development. If public perception causes the value of critical habitat acres to be diminished, these acres are those most likely to be affected. Due to existing data limitations regarding the probability that such effects will occur, and the likely degree to which property values will be affected, we are unable to estimate the magnitude of perception-related costs that could result from the designation if finalized. However, the cost cannot exceed the total value of affected properties. Based on our analysis, the value of potentially affected parcels is unlikely to exceed $100 million.

Additional information and discussion regarding our economic analysis is available in our DEA available on the Internet at http://www. regulations.gov at Docket No. FWS-R8-ES-2013-0080.

As we stated earlier, we are soliciting data and comments from the public on the DEA, as well as all aspects of the proposed rule and our amended required determinations. We may revise the proposed rule or supporting documents to incorporate or address information we receive during the public comment period. In particular, we may exclude an area from critical habitat if we determine that the benefits of excluding the area outweigh the benefits of including the area, provided the exclusion will not result in the extinction of this species.

In our August 2, 2013, proposed rule (78 FR 46862), we indicated that we would defer our determination of compliance with several statutes and executive orders until we had evaluated the probable effects on landowners and stakeholders and the resulting probable economic impacts of the designation. Following our evaluation of the probable incremental economic impacts resulting from the designation of critical habitat for Ivesia webberi, we have amended or affirmed our determinations below. Specifically, we affirm the information in our proposed rule concerning Executive Orders (E.O.s) 12866 and 13563 (Regulatory Planning and Review), E.O. 13132 (Federalism), E.O. 12988 (Civil Justice Reform), E.O. 13211 (Energy, Supply, Distribution, and Use), the Unfunded Mandates Reform Act (2 U.S.C. 1501 et seq. ), the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq. ), the National Environmental Policy Act (42 U.S.C. 4321 et seq. ), and the President's memorandum of April 29, 1994, “Government-to-Government Relations with Native American Tribal Governments” (59 FR 22951). However, based on our evaluation of the probable incremental economic impacts of the proposed designation of critical habitat for I. webberi, we are amending our required determinations concerning the Regulatory Flexibility Act (5 U.S.C. 601 et seq. ) and E.O. 12630 (Takings).

Under the Regulatory Flexibility Act (RFA; 5 U.S.C. 601 et seq. ), as amended by the Small Business Regulatory Enforcement Fairness Act of 1996 (SBREFA; 5 U.S.C. 801 et seq. ), whenever an agency publishes a notice of rulemaking for any proposed or final rule, it must prepare and make available for public comment a regulatory flexibility analysis that describes the effects of the rule on small entities (i.e., small businesses, small organizations, and small government jurisdictions). However, no regulatory flexibility analysis is required if the head of the agency certifies the rule will not have a significant economic impact on a substantial number of small entities. The SBREFA amended the RFA to require Federal agencies to provide a certification statement of the factual basis for certifying that the rule will not have a significant economic impact on a substantial number of small entities.

According to the Small Business Administration, small entities include small organizations such as independent nonprofit organizations; small governmental jurisdictions, including school boards and city and town governments that serve fewer than 50,000 residents; and small businesses (13 CFR 121.201). Small businesses include manufacturing and mining concerns with fewer than 500 employees, wholesale trade entities with fewer than 100 employees, retail and service businesses with less than $5 million in annual sales, general and heavy construction businesses with less than $27.5 million in annual business, special trade contractors doing less than $11.5 million in annual business, and agricultural businesses with annual sales less than $750,000. To determine if potential economic impacts to these small entities are significant, we considered the types of activities that might trigger regulatory impacts under this designation as well as types of project modifications that may result. In general, the term “significant economic impact” is meant to apply to a typical small business firm's business operations.

The Service's current understanding of the requirements under the RFA, as amended, and following recent court decisions, is that Federal agencies are only required to evaluate the potential incremental impacts of rulemaking on those entities directly regulated by the rulemaking itself, and therefore, not required to evaluate the potential impacts to indirectly regulated entities. The regulatory mechanism through which critical habitat protections are realized is section 7 of the Act, which requires Federal agencies, in consultation with the Service, to ensure that any action authorized, funded, or carried by the agency is not likely to adversely modify critical habitat. Therefore, under these circumstances only Federal action agencies are directly subject to the specific regulatory requirement (avoiding destruction and adverse modification) imposed by critical habitat designation. Under these circumstances, it is our position that only Federal action agencies will be directly regulated by this designation. Federal agencies are not small entities and to this end, there is no requirement under RFA to evaluate the potential impacts to entities not directly regulated. Therefore, because no small entities are directly regulated by this rulemaking, the Service certifies that, if promulgated, the proposed critical habitat designation will not have a significant economic impact on a substantial number of small entities.

In summary, we have considered whether the proposed designation would result in a significant economic impact on a substantial number of small entities. For the above reasons and based on currently available information, we certify that, if promulgated, the proposed critical habitat designation would not have a significant economic impact on a substantial number of small business entities. Therefore, an initial regulatory flexibility analysis is not required.

In accordance with E.O. 12630 (Government Actions and Interference with Constitutionally Protected Private Property Rights), we have analyzed the potential takings implications of designating critical habitat for Ivesia webberi in a takings implications assessment. As discussed above, the designation of critical habitat affects only Federal actions. Although private parties that receive Federal funding, assistance, or require approval or authorization from a Federal agency for an action may be indirectly impacted by the designation of critical habitat, the legally binding duty to avoid destruction or adverse modification of critical habitat rests squarely on the Federal agency. The DEA found that no significant economic impacts are likely to result from the designation of critical habitat for I webberi. Because the Act's critical habitat protection requirements apply only to Federal agency actions, few conflicts between critical habitat and private property rights should result from this designation. Based on information contained in the DEA and described within this document, it is not likely that economic impacts to a property owner would be of a sufficient magnitude to support a takings action. Therefore, the takings implications assessment concludes that this designation of critical habitat for I. webberi does not pose significant takings implications for lands within or affected by the designation.

The primary authors of this notice are the staff members of the Pacific Southwest Regional Office (Region 8), with assistance from staff of the Nevada Fish and Wildlife Office, U.S. Fish and Wildlife Service.

Accordingly, we propose to further amend part 17, subchapter B of chapter I, title 50 of the Code of Federal Regulations, as proposed to be amended on August 2, 2013, at 78 FR 46862, as set forth below: