State of Wisconsin v. EPA ( 2019 )


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  •  United States Court of Appeals
    FOR THE DISTRICT OF COLUMBIA CIRCUIT
    Argued October 3, 2018            Decided September 13, 2019
    No. 16-1406
    STATE OF WISCONSIN, ET AL.,
    PETITIONERS
    v.
    ENVIRONMENTAL PROTECTION AGENCY AND ANDREW
    WHEELER, ADMINISTRATOR, UNITED STATES
    ENVIRONMENTAL PROTECTION AGENCY,
    RESPONDENTS
    AMERICAN LUNG ASSOCIATION, ET AL.,
    INTERVENORS
    Consolidated with 16-1428, 16-1429, 16-1432, 16-1436,
    16-1437, 16-1438, 16-1439, 16-1440, 16-1441, 16-1442,
    16-1443, 16-1444, 16-1445, 16-1448, 17-1066
    On Petitions for Review of Final Action of the
    United States Environmental Protection Agency
    Neil Gormley argued the cause for petitioners
    Conservation Groups. Valerie S. Edge, Deputy Attorney
    General, Office of the Attorney General for the State of
    Delaware, argued the cause for petitioner State of Delaware.
    2
    With them on the briefs were David Baron, Charles
    McPhedran, Joshua R. Stebbins, and Zachary M. Fabish. Seth
    L. Johnson entered an appearance.
    Misha Tseytlin, Solicitor General, Office of the Attorney
    General for the State of Wisconsin, and Harvey M. Sheldon
    argued the causes for State Petitioners, Cedar Falls Utilities,
    and City of Ames, Iowa. With them on the briefs were Brad
    D. Schimel, Attorney General, Luke N. Berg, Deputy Solicitor
    General, Peter Michael, Attorney General, Office of the
    Attorney General for the State of Wyoming, James Kaste,
    Deputy Attorney General, Erik Petersen, Senior Assistant
    Attorney General, Leslie Sue Ritts, Steve Marshall, Attorney
    General, Office of the Attorney General for the State of
    Alabama, Robert D. Tambling, Assistant Attorney General,
    Leslie Rutledge, Attorney General, Office of the Attorney
    General for the State of Arkansas, Nicholas J. Bronni, Deputy
    Solicitor General, Michael DeWine, Attorney General, Office
    of the Attorney General for the State of Ohio, Eric E. Murphy,
    State Solicitor, Ken Paxton, Attorney General, Office of the
    Attorney General for the State of Texas, Priscilla M. Hubenak,
    and Craig J. Pritzlaff and Linda B. Secord, Assistant Attorneys
    General. Andrew L. Brasher, Deputy Solicitor, Office of the
    Attorney General for the State of Alabama, Michael J.
    McGrady, Senior Assistant Attorney General, Office of the
    Attorney General for the State of Wyoming, Lee P. Rudofsky,
    Solicitor, Office of the Attorney General for the State of
    Arkansas, and Ryan Walsh entered appearances.
    Norman W. Fichthorn, Aaron M. Streett, and C. Grady
    Moore, III argued the causes for Industry Petitioners. With
    them on the briefs were E. Carter Chandler Clements, Peter S.
    Glaser, Margaret Claiborne Campbell, M. Buck Dixon, Scott
    C. Oostdyk, E. Duncan Getchell, Jr., Michael H. Brady, Jane
    E. Montgomery, J. Michael Showalter, Amy Antoniolli, P.
    3
    Stephen Gidiere, III, Julia B. Barber, David W. Mitchell,
    Daniel J. Kelly, David M. Flannery, Kathy G. Beckett, Edward
    L. Kropp, Megan H. Berge, Charles T. Wehland, Todd E.
    Palmer, John A. Sheehan, Valerie L. Green, Ben H. Stone,
    Terese T. Wyly, M. Brant Pettis, Louis E. Tosi, Cheri A.
    Budzynski, and Michael A. Born. Alina Fortson and Jordan
    Hemaidan entered appearances.
    Amy J. Dona and Chloe H. Kolman, Attorneys, U.S.
    Department of Justice, argued the causes for respondents. With
    them on the brief were Jonathan Brightbill, Deputy Assistant
    Attorney General, and Stephanie L. Hogan, Attorney, U.S.
    Environmental Protection Agency.
    E. Carter Chandler Clements argued the cause for Industry
    Respondent-Intervenors. With her on the brief were Norman
    W. Fichthorn, Peter S. Glaser, Margaret Claiborne Campbell,
    M. Buck Dixon, Scott C. Oostdyk, E. Duncan Getchell, Jr.,
    Michael H. Brady, Robert A. Manning, and Joseph A. Brown.
    Andrew G. Frank, Assistant Attorney General, argued the
    cause for State Intervenors. With him on the brief were Eric T.
    Schneiderman, Attorney General at the time the brief was filed,
    Office of the Attorney General for the State of New York,
    Barbara D. Underwood, Solicitor General, Steven C. Wu,
    Deputy Solicitor General, Michael J. Myers, Senior Counsel,
    Maura Healey, Attorney General, Office of the Attorney
    General for the Commonwealth of Massachusetts, Jillian M.
    Riley, Assistant Attorney General, Environmental Protection
    Division, Peter F. Kilmartin, Attorney General, Rhode Island
    Department of Attorney General, Gregory S. Schultz, Special
    Assistant Attorney General, Brian E. Frosh, Attorney General,
    Office of the Attorney General for the State of Maryland,
    Michael F. Strande, Assistant Attorney General, Gordon J.
    MacDonald, Attorney General, K. Allen Brooks, Assistant
    4
    Attorney General, New Hampshire Office of the Attorney
    General, Thomas J. Donovan, Jr., Attorney General, Office of
    the Attorney General for the State of Vermont, and Nicholas F.
    Persampieri, Assistant Attorney General. Morgan A. Costello,
    Assistant Attorney General, Office of the Attorney General for
    the State of New York, entered an appearance.
    Charles McPhedran argued the cause for Public Health
    and Environmental Intervenors. With him on the brief were
    Sean H. Donahue, Susannah L. Weaver, Graham G. McCahan,
    Vickie L. Patton, Ann Brewster Weeks, Neil Gormley, David
    Baron, Howard Fox, Joshua R. Stebbins, and Zachary M.
    Fabish.
    Hope M. Babcock was on the brief for amicus curiae
    American Thoracic Society in support of respondent-
    intervenors American Lung Association, Appalachian
    Mountain Club, Environmental Defense Fund, and Sierra Club.
    Before: SRINIVASAN, MILLETT and WILKINS, Circuit
    Judges.
    PER CURIAM: When upwind States pollute, downwind
    States can suffer the consequences. Congress addressed that
    problem in the Clean Air Act by enacting a “Good Neighbor
    Provision.” The Provision requires upwind States to eliminate
    their significant contributions to air quality problems in
    downwind States.
    In 2016, the Environmental Protection Agency
    implemented that requirement by promulgating a regulation
    addressing the interstate transport of ozone, or smog. A
    number of parties brought challenges to the Rule, some
    contending that the Rule is too strict and others contending that
    it is too lenient.
    5
    We conclude that, in one respect, the Rule is inconsistent
    with the Act: it allows upwind States to continue their
    significant contributions to downwind air quality problems
    beyond the statutory deadlines by which downwind States must
    demonstrate their attainment of air quality standards. In all
    other respects, though, we determine that EPA acted lawfully
    and rationally.
    I
    The Clean Air Act tasks EPA with setting national ambient
    air quality standards, or NAAQS. See 
    42 U.S.C. § 7409
    (a).
    Individual States must ensure that their ambient air quality
    complies with the national standard. To that end, the Clean Air
    Act requires States to adopt State implementation plans, or
    SIPs, that provide for implementation, maintenance and
    enforcement of the national standard. 
    Id.
     § 7410(a)(1). If a
    State fails to submit a SIP, or if EPA disapproves it, EPA must
    issue a federal implementation plan, or FIP, to correct any
    deficiency. Id. § 7410(c)(1).
    State-level regulation of air quality faces a confounding
    variable. Air pollution, once emitted, drifts with the wind.
    Upwind pollutants affect air quality in downwind States via
    various chemical processes. Ozone, for example, forms from
    the interaction of nitrogen oxides (NOx) and volatile organic
    compounds (VOCs) in the presence of sunlight. For downwind
    States, upwind emissions of these ozone precursors can pose a
    significant problem. According to a study referenced by EPA,
    on average, over three-quarters of the ground-level ozone in
    downwind States comes from upwind emissions. 81 Fed. Reg.
    at 74,514.
    6
    Congress included a Good Neighbor Provision in the
    Clean Air Act to address the problem of upwind States’
    pollution impairing downwind States’ air quality. The
    Provision prohibits States from “emitting any air pollutant in
    amounts” that will “contribute significantly to nonattainment”
    or “interfere with maintenance” of air quality in other States.
    
    42 U.S.C. § 7410
    (a)(2)(D)(i).
    EPA has addressed the Good Neighbor Provision’s
    requirements in a series of rulemakings. In 2011, EPA
    promulgated the Cross-State Air Pollution Rule (CSAPR),
    which applied to States whose upwind pollution violated good
    neighbor obligations under the 1997 ozone NAAQS and the
    1997 and 2006 fine particulate matter NAAQS. See 
    76 Fed. Reg. 48,208
     (Aug. 8, 2011).
    In 2008, EPA reduced the ozone NAAQS from 80 parts
    per billion (ppb) to 75 ppb. As a result, EPA promulgated the
    rule at issue in this case: an update to the CSAPR for eastern
    States that accounts for the stricter 2008 ozone NAAQS. See
    Cross-State Air Pollution Rule Update for the 2008 Ozone
    NAAQS, 
    81 Fed. Reg. 74,504
     (Oct. 26, 2016) (Update Rule).
    Under the Update Rule, EPA proceeded in four steps.
    At the first step, EPA identified downwind States expected
    to have problems attaining or maintaining air quality in
    compliance with the 2008 ozone NAAQS. To identify those
    States, EPA had to estimate the future air quality in each State.
    
    Id. at 74
    ,516–17. EPA devised a measure to turn 2011 ozone
    measurements into 2017 projections.
    EPA started with 2011 modeled data from “receptors,”
    devices in each State that measure air quality. EPA modeled
    ozone concentrations in a three-by-three grid around each
    receptor. EPA chose the ten days with the highest projected
    7
    ozone concentration, noted which of the nine 12-km2 grid cells
    had the highest ozone concentration on that day, and averaged
    the ten observations. See 
    id. at 74
    ,526–27. EPA then ran the
    model for 2017, inputting 2011 environmental conditions (like
    rainfall and fire emissions) but projected 2017 NOx emissions
    rates. The percentage change from 2011 to 2017 was deemed
    a receptor’s “relative response factor,” which measures the
    sensitivity of an area to ozone formation. Multiplying a 2011
    observation by the relevant response factor yielded a projection
    for 2017 for the receptor.
    EPA projected 2017 ozone levels for each receptor by
    applying the relative response factor to three “design values”
    from a receptor across a five-year period. A “design value” is
    a three-year historical average of monitored ozone data. The
    selected design values represented 2009–2011, 2010–2012,
    and 2011–2013. See 
    id. at 74,532
    . Multiplying the three
    design values by the applicable relative response factor resulted
    in three different ozone projections for 2017.
    In light of the 2008 ozone NAAQS of 75 ppb, EPA
    considered any projected value of up to 75.9 ppb to constitute
    attainment.    
    Id.
        EPA defined a receptor to be in
    “nonattainment” status if the average of its three projected
    design values and its most recent monitored design value
    (2013-2015) exceeded the NAAQS. 
    Id.
     EPA also identified a
    third category (beyond attainment and nonattainment): a
    receptor would be deemed in “maintenance” status if the
    highest of the three projected design values exceeded the
    NAAQS but the other two values did not. 
    Id.
    At the second step, EPA identified those upwind States
    whose pollution was linked to nonattainment or
    nonmaintenance at downwind receptors. EPA quantified the
    impact of each State’s pollution on downwind receptors using
    8
    a model that apportioned responsibility for ozone formation at
    a given receptor to various categories of emitters. See 
    id. at 74,536
    . EPA then multiplied a given State’s contribution
    factor by the projected average ozone concentration at each
    receptor (calculated in Step 1) to yield each State’s contribution
    to ozone formation at each downwind receptor.
    Next, EPA screened out States whose contributions to
    ozone formation in a downwind State comprised less than 1%
    of the NAAQS (0.75 ppb) in that downwind State. See 
    id. at 74,537
    .      In other words, EPA construed “contribute
    significantly” and “interfere with” in the Good Neighbor
    Provision to require an upwind State’s pollution to cause at
    least 0.75 ppb of ozone formation in a downwind State. EPA’s
    analysis concluded that twenty-three States and the District of
    Columbia were linked to nonattainment or nonmaintenance in
    at least one downwind State. Fourteen States’ contributions
    fell below the 1% threshold and thus were screened out at this
    step. See 
    id.
    At the third step, EPA quantified the amount of emissions
    reductions that the twenty-three upwind States and the District
    of Columbia would be required to make under the Good
    Neighbor Provision. To do so, EPA applied a multifactor test
    that balanced costs against benefits.
    EPA first measured the emissions reductions that would
    occur at various levels of cost controls. It began with a baseline
    case (i.e., a cost-control level of $0). It then ran the model for
    a cost-control level of $800 per ton—in other words, measuring
    the emissions reductions that would occur if EPA required all
    States to apply all possible emissions controls at its EGUs
    (electric generating units, or power plants) up to the marginal
    price of $800 per ton of NOx. See 
    id. at 74
    ,540–41. EPA then
    ran the model for higher cost-control levels of $1,400/ton,
    9
    $3,400/ton, $5,000/ton, and $6,400/ton. For each of these cost-
    control levels, EPA also estimated the air quality
    improvements that would occur at each receptor in downwind
    States. Comparing the cost-control levels against the resulting
    emissions reductions and air quality improvements, EPA
    concluded that the cost-control level of $1,400 per ton
    represented the point at which upwind “NOx reduction
    potential and corresponding downwind ozone air quality
    improvements are maximized with respect to marginal cost” —
    that is, the point at which EPA would get the biggest bang for
    its buck. 
    Id. at 74,550
    .
    As part of that analysis, EPA also performed an
    “overcontrol” analysis to ensure that no upwind State would be
    required to reduce its emissions more than called for by the
    Good Neighbor Provision. Overcontrol would occur if either
    (1) a State’s downwind receptors all reduced their ozone
    concentrations below the NAAQS, or (2) a State’s
    contributions to all downwind receptors was reduced below the
    1% contribution threshold of 0.75 ppb. See EME Homer City
    Gen., L.P. v. EPA, 
    572 U.S. 489
    , 521 (2014) (“EME Homer
    II”). EPA concluded that neither of those indicia of overcontrol
    existed at the $800/ton and $1,400/ton cost-control levels. See
    81 Fed. Reg. at 74,551–52.
    At the fourth step, EPA quantified State emissions
    “budgets” by calculating the emissions amount that would
    occur under $1,400/ton cost controls. Under the CSAPR,
    States may emit more NOx than permitted by their budgets by
    acquiring allowances from other States, and States may sell
    allowances to other States if they reduce their emissions more
    than required by their budgets. Id. at 74,554. But to ensure
    that a State does not entirely skirt its good neighbor obligations
    by buying a large number of allowances, each State is limited
    10
    to emitting no more than 121% of the emissions budget (the
    “assurance level”), irrespective of allowances. See id.
    After EPA promulgated the original CSAPR, various
    parties brought a challenge to that rule. We initially vacated
    the rule, see EME Homer City Generation, L.P. v. EPA, 
    696 F.3d 7
     (D.C. Cir. 2012) (“EME Homer I”), but the Supreme
    Court reversed our decision and upheld the rule in its entirety,
    although it left open the possibility of as-applied challenges,
    see EME Homer II, 572 U.S. at 495. On remand, we found that
    emissions budgets for thirteen States were invalid due to
    overcontrol. EME Homer City Generation, L.P. v. EPA, 
    795 F.3d 118
    , 124 (D.C. Cir. 2015) (“EME Homer III”).
    In 2016, EPA promulgated the Update Rule at issue here.
    A number of parties have petitioned for review of the Rule in
    this court. See 
    42 U.S.C. § 7607
    (d)(9). One group of
    petitioners, including environmental groups and the State of
    Delaware (collectively, Environmental Petitioners), contends
    that EPA was required to adopt a more stringent rule. Another
    group of petitioners, including various States and industry
    groups (collectively, State and Industry Petitioners), argues
    that EPA was required to issue a more lenient rule.
    II
    We begin by addressing Environmental Petitioners’
    claims. Environmental Petitioners challenge the Update Rule
    on the grounds that it: (i) fails to square with the statutory
    attainment deadlines, (ii) makes impermissible modeling and
    implementation choices, and (iii) incorrectly classifies
    Delaware as an attaining downwind State.
    The Rule must be set aside if it is “arbitrary, capricious, an
    abuse of discretion, or otherwise not in accordance with law”
    11
    or “in excess of statutory jurisdiction, authority, or limitations.”
    
    42 U.S.C. § 7607
    (d)(9). That standard is “essentially the same”
    as the familiar standard of review contained in § 706(2) of the
    Administrative Procedure Act. Ethyl Corp. v. EPA, 
    51 F.3d 1053
    , 1064 (D.C. Cir. 1995).
    Applying that standard, we agree with Environmental
    Petitioners that the Rule is inconsistent with the Act’s
    attainment deadlines. We reject Environmental Petitioners’
    remaining claims.
    A
    We first consider Environmental Petitioners’ argument
    that the Update Rule infringes the Good Neighbor Provision by
    permitting upwind States to continue their significant
    contributions to downwind air quality problems for too long—
    i.e., past the statutory deadlines for nonattaining downwind
    areas to meet the NAAQS for ozone. In fact, EPA set no
    concrete deadline at all for upwind States to eliminate their
    contributions to downwind States’ nonattainment.
    The Good Neighbor Provision requires States to submit
    SIPs that “prohibit[], consistent with the provisions of this
    subchapter [i.e., Title I of the Act], any source . . . from emitting
    any air pollutant in amounts which will . . . contribute
    significantly to nonattainment in . . . any other State with
    respect to any” NAAQS. 
    42 U.S.C. § 7410
    (a)(2)(D)(i). If a
    State fails to submit a SIP or submits one deemed inadequate,
    such that EPA must then prepare a FIP, EPA must likewise
    satisfy the Good Neighbor Provision in the FIP. See EME
    Homer II, 572 U.S. at 512–14 & n.15.
    The question we face is one of timing: the Good Neighbor
    Provision calls for upwind States to eliminate their significant
    12
    contributions to air pollution in downwind States, but by when
    must upwind States do so? In particular, does the Provision
    call for upwind States to eliminate their significant
    contributions to downwind pollution by the deadlines for
    downwind areas to comply with the relevant NAAQS—here,
    the 2008 NAAQS for ozone?
    Those deadlines are prescribed by the Act. The Act first
    tasks EPA with designating as “nonattainment” any area that
    does not meet a NAAQS. See 
    42 U.S.C. § 7407
    (d)(1)(A). For
    areas designated as nonattainment for ozone, the Act specifies
    that each State must secure compliance “as expeditiously as
    practicable but not later than” a date certain. 
    Id.
     § 7511(a)(1)
    (emphasis added). That date is July 20, 2018, for areas in
    “moderate” nonattainment with respect to the 2008 NAAQS
    (and was July 20, 2015 for areas in “marginal” nonattainment).
    See Nat. Res. Def. Council v. EPA, 
    777 F.3d. 456
    , 465–66
    (D.C. Cir. 2014); Implementation of the 2008 National
    Ambient Air Quality Standards for Ozone: State
    Implementation Plan Requirements, 
    80 Fed. Reg. 12,264
    ,
    12,268 (Mar. 6, 2015).
    The Update Rule does not require upwind States to
    eliminate their significant contributions to downwind ozone
    pollution by that date—or by any date, for that matter. EPA
    acknowledges that, except for one State (Tennessee), it “is only
    quantifying a subset of each State’s emission reduction
    obligation pursuant to the good neighbor provision.” 81 Fed.
    Reg. at 74,520 (emphasis added); see id. at 74,508 n.19. And
    the Rule states that it represents only a “first, partial step to
    addressing a given upwind State’s significant contribution to
    downwind air quality impacts for the 2008 ozone NAAQS.”
    Id. at 74,522. That is in large part because the Update Rule
    confines itself to addressing upwind contributions from EGUs
    due to an ostensible lack of information about non-EGUs. EPA
    13
    “expects that a full resolution of upwind transport obligations
    would require emission reductions from sectors besides
    EGUs,” along with “further EGU reductions that are
    achievable after 2017.” Id. The upshot is that, while the Rule
    calls for a certain level of reductions in upwind contributions
    by the 2017 ozone year—“in time to assist downwind states to
    meet the July 2018 attainment deadlines”—the Rule does not
    purport to require upwind States to fully meet their good
    neighbor obligations by that time. Id.
    Under the Update Rule, then, downwind States face a
    dilemma. On one hand, they operate under a statutory
    obligation to secure compliance with the ozone NAAQS by
    July 20, 2018. But on the other hand, the Rule does not require
    upwind States to eliminate their significant contributions to
    downwind pollution by that deadline.            Environmental
    Petitioners argue that the Rule is inconsistent with the Act in
    failing to require upwind States to eliminate their significant
    contributions in accordance with the deadline by which
    downwind States must come into compliance with the
    NAAQS. We agree.
    1
    That conclusion follows from our decision in North
    Carolina v. EPA, 
    531 F.3d 896
     (D.C. Cir. 2008). There, we
    considered essentially the same question we now face here:
    whether EPA can allow upwind States to continue their
    significant contributions to downwind pollution beyond the
    statutory deadlines for downwind States to meet the NAAQS.
    North Carolina involved the Clean Air Interstate Rule (CAIR),
    a prior EPA effort to implement the Good Neighbor Provision
    with regard to the then-applicable NAAQS for two pollutants,
    fine particulate matter (PM2.5) and ozone. See 
    id.
     at 903–06.
    Although the statutory deadline for nonattaining areas to
    14
    comply with those NAAQS was 2010, CAIR gave upwind
    States until 2015 to eliminate their significant contributions to
    downwind nonattainment. See 
    id. at 911
    .
    We held that CAIR’s “deadline of 2015 [was] unlawful.”
    
    Id. at 913
    . We explained that, under the terms of the Good
    Neighbor Provision, upwind States must eliminate their
    significant contributions “consistent with the provisions” of
    Title I of the Act. See 
    id.
     at 911–12; 
    42 U.S.C. § 7410
    (a)(2)(D)(i). And the incorporated provisions of Title I,
    we further explained, include ones setting the attainment
    deadlines for downwind areas. See 
    42 U.S.C. § 7502
    (a)(2)(A)
    (PM2.5); 
    id.
     § 7511 (ozone). But under CAIR, “downwind
    nonattainment areas [were required to] attain NAAQS for
    ozone and PM2.5” by 2010, “without the elimination” by then
    “of upwind states’ significant contribution to downwind
    nonattainment, forcing downwind areas to make greater
    reductions than [the Good Neighbor Provision] requires.”
    North Carolina, 
    531 F.3d at 912
    . As a result, we concluded,
    “EPA ignored its statutory mandate to promulgate CAIR
    consistent with the provisions in Title I mandating compliance
    deadlines for downwind states in 2010.” 
    Id.
    All of that is equally true here. Just as with CAIR, the
    CSAPR Update Rule we consider in this case fails to eliminate
    upwind States’ significant contributions to downwind pollution
    by the statutory deadline for downwind States to meet the
    NAAQS for ozone. That in turn “forc[es] downwind areas to
    make greater reductions than [the Good Neighbor Provision]
    requires.” 
    Id.
     Indeed, CAIR at least imposed some deadline
    for upwind States to fully satisfy their good neighbor
    obligations, albeit a deadline we held was too late. Here, by
    contrast, EPA established no deadline at all for upwind States
    to eliminate their significant contributions. And while EPA
    concluded that requiring upwind States to meet their good
    15
    neighbor obligations by the 2018 attainment deadline “simply
    [was] not feasible in the existing timeframe,” 
    81 Fed. Reg. 74,523
    , in North Carolina, EPA had likewise sought
    (unsuccessfully) to rely “on reasons of feasibility.” 
    531 F.3d at 911
    .
    EPA contends that North Carolina required it only to
    “consider” the attainment deadline in some fashion when
    establishing upwind States’ good neighbor responsibilities, not
    to align the attainment deadline with the deadline for satisfying
    good neighbor obligations. And EPA argues that the Update
    Rule gives the requisite consideration to the July 2018
    attainment deadline by requiring at least some level of good
    neighbor reductions by that date.
    North Carolina, though, requires more than merely
    “considering” attainment deadlines in that manner. In fact,
    CAIR provided for a first phase of reductions in upwind
    contributions to take place before the attainment deadlines. See
    
    id. at 903
    . But that was not enough to satisfy the statute. The
    problem was that the eventual elimination of significant
    upwind contributions in the second phase of reductions would
    occur only long after the attainment deadlines had passed.
    We explained that EPA needed to “harmonize” the “Phase
    Two deadline for upwind contributors to eliminate their
    significant contribution with the attainment deadlines for
    downwind areas.” 
    Id. at 912
     (emphasis added). Otherwise,
    downwind areas would need to attain the NAAQS “without the
    elimination of upwind states’ significant contribution.” 
    Id.
    The Rule here creates the same situation. (And we note it does
    so with respect to both the 2018 and 2015 deadlines. Although
    EPA contends that the claim as to the 2015 deadlines was
    forfeited, we disagree. See Comment of Sierra Club et al., at
    16
    8–9, EPA Docket No. 2015-0500-0287 (Feb. 1, 2016), J.A.
    1015–16.)
    EPA notes that, when we addressed the issue of the
    appropriate remedy at the conclusion of our opinion in North
    Carolina, we observed that EPA would need to “decide what
    date, whether 2015 or earlier, is as expeditious as practicable
    for states to eliminate their significant contributions to
    downwind nonattainment.” 561 F.3d at 930 (emphasis added).
    But our reference to 2015 did not suggest that EPA could delay
    the deadline for upwind States to eliminate their significant
    contributions until 5 years after the 2010 attainment deadline.
    The entire object of our analysis was to reject the notion that
    the Phase Two deadline of 2015 could be squared with the
    Good Neighbor Provision. See id. at 913 (EPA operated “under
    the assumption that 2015 was an appropriate deadline for CAIR
    compliance. It is not.”). Rather, we presumably referred to
    2015 because, as we had earlier specifically noted, EPA has
    separate statutory authority to extend the deadline for attaining
    the NAAQS for PM2.5—and thereby correspondingly also
    extend the good neighbor deadline—for up to five years, or
    until 2015. See id. at 911 (citing 
    42 U.S.C. § 7502
    (a)(2)(A)).
    In sum, under our decision in North Carolina, the Good
    Neighbor Provision calls for elimination of upwind States’
    significant contributions on par with the relevant downwind
    attainment deadlines. The Update Rule fails to do so.
    2
    North Carolina’s understanding of the Good Neighbor
    Provision is confirmed by examining the Update Rule under
    the framework set out in Chevron U.S.A. Inc. v. Nat. Res. Def.
    Council, Inc., 
    467 U.S. 837
     (1984). See EME Homer II, 572
    U.S. at 512–14 (evaluating previous EPA implementation of
    17
    the Good Neighbor Provision under Chevron); see also Util.
    Air Regulatory Grp. v. EPA, 
    573 U.S. 302
    , 315 (2014) (“We
    review EPA’s interpretations of the Clean Air Act using the
    standard set forth in Chevron.”).
    “Under Chevron, we presume that when an agency-
    administered statute is ambiguous with respect to what it
    prescribes, Congress has empowered the agency to resolve the
    ambiguity.” Util. Air. Regulatory Grp., 573 U.S. at 315. The
    question then “is whether in doing so the agency has acted
    reasonably and thus has ‘stayed within the bounds of its
    statutory authority.’” Id. (quoting Arlington v. FCC, 
    569 U.S. 290
    , 296 (2013)). Here, the Update Rule’s open-ended
    compliance timeframe exceeds the bounds of EPA’s statutory
    authority by allowing upwind States to continue their
    significant contributions to downwind nonattainment well past
    the deadline for downwind areas to comply with the NAAQS.
    The threshold question under Chevron ordinarily would be
    whether the statute is ambiguous on that issue, such that the
    agency then would have discretion to choose among reasonable
    interpretations. E.g., 
    id.
     But there is no need to resolve that
    threshold issue in this case, because, regardless of ambiguity,
    the Update Rule amounts to an unreasonable—and hence
    impermissible—interpretation of the statute in any event. See
    Michigan v. EPA, 
    135 S. Ct. 2699
    , 2707 (2015); Massachusetts
    v. U.S. Dep’t of Transp., 
    93 F.3d 890
    , 892 (D.C. Cir. 1996)
    (declining to resolve how Chevron might apply because “the
    agency’s determination here cannot be upheld with or without
    deference”).
    The Good Neighbor Provision, as North Carolina
    emphasized, requires upwind States to eliminate their
    significant contributions to downwind pollution “consistent
    with the provisions of this subchapter,” i.e., Title I of the Clean
    18
    Air Act. 
    42 U.S.C. § 7410
    (a)(2). One of the “provisions of
    this subchapter” is § 7511(a)(1), which in turn requires
    downwind areas in moderate nonattainment to attain the
    NAAQS by July 20, 2018. See id. § 7511(a)(1); 81 Fed. Reg.
    at 74,507. The statute cannot reasonably be understood to
    enable upwind States to continue their significant contributions
    outside of the statutory timeframe by which downwind areas
    must achieve attainment, much less continue those
    contributions with no deadline at all.
    We note that we do not conclude that the phrase
    “consistent with” in the Good Neighbor Provision necessarily
    effects an incorporation of the full contours of every provision
    of Title I in pure, lockstep fashion. As we have observed
    elsewhere in construing the same words in the context of the
    same statute, the phrase “consistent with” other statutory
    sections “calls for congruence or compatibility with those
    sections, not lock-step correspondence.” Envtl. Def. Fund Inc.
    v. EPA, 
    82 F.3d 451
    , 460 (D.C. Cir. 1996); see Nuclear Energy
    Institute, Inc. v. EPA, 
    373 F.3d 1251
    , 1270 (D.C. Cir. 2004)
    (The “‘based upon and consistent with’ standard does not
    require EPA to walk in lockstep”).
    Rather, it is the statutorily designed relationship between
    the Good Neighbor Provision’s obligations for upwind States
    and the statutory attainment deadlines for downwind areas that
    generally calls for parallel timeframes. The Good Neighbor
    Provision was enacted “to enable downwind States to keep
    their levels of [air pollution] in check.” EME Homer II, 572
    U.S. at 496–97. A “reasonable statutory interpretation” of the
    Provision “must account for . . . the broader context of the
    statute as a whole.” Util. Air Regulatory Grp., 573 U.S. at 321.
    And the attainment deadlines, the Supreme Court has said, are
    “the heart” of the Act. Train v. Nat. Res. Def. Council, 
    421 U.S. 60
    , 66 (1975); see Sierra Club v. EPA, 
    294 F.3d 155
    , 161
    19
    (D.C. Cir. 2002) (“the attainment deadlines are central to the
    regulatory scheme”) (alteration and internal quotation marks
    omitted). The Act’s central object is the “attain[ment] [of] air
    quality of specified standards [within] a specified period of
    time.” Train, 
    421 U.S. at
    64–65.
    EPA’s interpretation of the Good Neighbor Provision
    subverts that scheme. Under the Update Rule, downwind
    States face a crucial statutory obligation to secure attainment
    of the ozone NAAQS by July 20, 2018 (or July 20, 2015), even
    though upwind States face no symmetrical obligation to
    eliminate their significant contributions to downwind
    nonattainment by that deadline. The Rule thus puts downwind
    States to the choice of flouting the attainment deadlines or
    making greater reductions than the Good Neighbor Provision
    requires. That choice is “incompatible with the substance of
    Congress’ regulatory scheme.” Util. Air Regulatory Grp., 573
    U.S. at 322 (internal quotation marks omitted).
    That becomes particularly evident when one considers the
    extent to which pollution from upwind States adversely affects
    the ability of downwind States to attain the NAAQS.
    According to a study EPA cited in the Update Rule’s preamble,
    “on average 77 percent of each state’s ground-level ozone is
    produced by precursor emissions from upwind states.” 81 Fed.
    Reg. at 74,514.
    Consider, in this regard, the Rule’s 2017 projections for
    one nonattainment area: Fairfield County, Connecticut. EPA
    projects that, after the good neighbor reductions called for by
    the Rule, a monitor in that area would observe an average
    ozone concentration of 76.5 ppb, or 1.5 ppb more than the
    NAAQS. Office of Air Quality Planning and Standards, U.S.
    Environmental Protection Agency, Air Quality Modeling
    Technical Support Document for the Final Cross State Air
    20
    Pollution Rule 14 (Aug. 2016). According to EPA, 53.82 ppb
    of that 76.5 ppb would be caused by pollution from U.S. States
    (including Connecticut itself). Appendix C, Contributions to
    2017 8-Hour Ozone Design Values at Projected 2017
    Nonattainment and Maintenance-Only Sites at C-4 (Aug.
    2016). Yet Connecticut’s own emissions, according to EPA’s
    projections, would account for only 3.89 ppb of that 53.82. Id.
    at C-3. The rest would come from upwind contributions, with
    a significant share from one State alone (New York, which is
    projected to contribute 17.22 ppb). Id.
    Because Connecticut does not get enough help from
    upwind States under the Update Rule, if Connecticut wanted to
    bring Fairfield County into attainment by the 2018 deadline, it
    would need to reduce its own ozone precursor emissions by
    almost 40% (1.5 ppb over 3.89). And missing that attainment
    deadline carries serious consequences, triggering a host of
    strict mandatory emissions controls and a bump-up from
    “moderate” to “serious” nonattainment status. See South Coast
    Air Quality Mgmt. Dist. v. EPA, 
    472 F.3d 882
    , 887 (D.C. Cir.
    2006); 
    42 U.S.C. § 7511
    (a). That has recently occurred for
    eight nonattainment areas which failed to meet the NAAQS by
    the July 2018 deadline, including Fairfield County. 
    84 Fed. Reg. 44,239
     (Aug. 23, 2019).
    The structure of the provision establishing the statutory
    attainment deadlines for ozone reinforces the Update Rule’s
    impermissibility. That provision calls for downwind States to
    secure attainment “as expeditiously as practicable but not later
    than” the deadline. 
    42 U.S.C. § 7511
    (a). The deadline, that is,
    functions as the ultimate failsafe. By imposing a first-order
    obligation to attain the NAAQS “as expeditiously as
    practicable,” Congress “made clear that the States could not
    procrastinate until the deadline approached. Rather, the
    primary standards had to be met in less [time] if possible.”
    21
    Union Elec. Co. v. EPA, 
    427 U.S. 246
    , 259–60 (1976). In light
    of that mandate, EPA “does not dispute that it has an obligation
    to implement [upwind States’] Good Neighbor emission
    reductions as expeditiously as practicable to benefit affected
    downwind areas.” EPA’s Br. 26.
    But if EPA must provide for upwind States to satisfy their
    good neighbor obligations as “expeditiously as practicable,”
    per the provision establishing the attainment deadlines, why is
    it not also generally necessary for upwind States to satisfy their
    good neighbor obligations by the ultimate attainment deadline
    as a last resort, per the same provision? By structuring the
    Update Rule to require upwind States to meet their good
    neighbor requirements as expeditiously as practicable, but then
    permitting States to continue their significant contributions
    well past the attainment deadlines, EPA gives effect to the
    “expeditiously as practicable” part of § 7511(a) without giving
    any independent effect to the deadlines part of that provision.
    EPA argues that the § 7511(a) attainment deadlines need
    not carry over to the Good Neighbor Provision because those
    deadlines are subject to modification by other statutory
    provisions. But those modification provisions do not render
    the deadlines discretionary or otherwise rob them of legal
    force. See Sierra Club, 
    294 F.3d at 161
     (holding that
    Ҥ 7511(a)(1), as written[,] sets a deadline without an
    exception”). Rather, if a modified attainment deadline applies
    to downwind States, EPA may be able, if justified, to make a
    corresponding extension for an upwind State’s good neighbor
    obligations. EPA makes no contention that any such
    modification is applicable here.
    As a last argument, EPA contends that holding upwind
    States to the downwind attainment deadlines would be
    inconsistent with the timeframe for promulgating a FIP. Under
    22
    the Act, the first downwind attainment deadline can occur
    within five years of the establishment of an ozone NAAQS.
    See 
    42 U.S.C. § 7407
    (d)(1)(B)(i); § 7511(a)(1). But, EPA
    notes, the statute contemplates that it might take more than six
    years to promulgate a FIP. See id. § 7410(a)(1), (c)(1),
    (k)(1)(B), (k)(2). Thus, EPA submits, upwind States cannot
    have been expected to cease their significant contributions by
    the downwind attainment deadline.
    There is no inconsistency. Under the statute, EPA need
    not wait six years to issue a FIP. By shortening the deadline
    for a SIP submission, see id. § 7410(a)(1), and by issuing a FIP
    soon thereafter, see id. § 7410(c)(1), EPA could promulgate a
    FIP well before the first downwind attainment deadline. See
    EME Homer II, 572 U.S. at 509 (“After EPA has disapproved
    a SIP, the Agency can wait up to two years to issue a FIP . . . .
    But EPA is not obliged to wait two years or postpone its action
    even a single day.”).
    EPA’s argument, in this regard, also proves too much. By
    EPA’s logic, EPA can wait until after the nonattainment
    deadline to promulgate not only a FIP addressing unfulfilled
    good neighbor obligations, but also a FIP addressing in-State
    pollution control deficiencies. After all, the same provisions
    EPA cites here also appear to allow EPA to take six years to
    promulgate a FIP after finding that a State’s SIP will not bring
    that same State into attainment. See 
    42 U.S.C. § 7410
    (k)(1)(A)
    (FIPs may be promulgated when Administrator decides that a
    SIP does not “compl[y] with the provisions of this
    chapter”). This would suggest that no pollution control
    requirement, let alone the Good Neighbor Provision, need be
    complied with by the attainment deadline. Yet EPA does not
    suggest that the timeframes for a FIP somehow render the
    deadlines totally nonbinding. When EPA determines that a
    State’s SIP is inadequate, EPA presumably must issue a FIP
    23
    that will bring that State into compliance before upcoming
    attainment deadlines, even if the outer limit of the statutory
    timeframe gives EPA more time to formulate the FIP. See
    Sierra Club v. EPA, 
    294 F.3d 155
    , 161 (D.C. Cir. 2002) (“the
    attainment deadlines remain intact” even if procedural
    deadlines are missed or changed). The same is true when a
    State’s SIP fails to provide for the full elimination of the State’s
    significant contributions to downwind nonattainment.
    For these reasons, we conclude that, by issuing a Rule that
    does not call for upwind States to eliminate their substantial
    contributions to downwind nonattainment in concert with the
    attainment deadlines, EPA has strayed outside the bounds of its
    statutory authority under the Good Neighbor Provision.
    3
    EPA invokes various justifications for allowing substantial
    upwind contributions to continue beyond the downwind
    attainment deadlines.       None of the agency’s asserted
    justifications establishes cause to disregard the requirement
    under the statute to align the deadline for satisfying good
    neighbor obligations with the deadline for attaining the
    NAAQS.
    First, EPA opted to require partial (rather than full)
    satisfaction of upwind States’ good neighbor obligations due in
    significant part to its decision to consider only upwind
    emissions from EGUs. EPA decided against considering
    emissions reductions from non-EGUs because, “[a]s compared
    to EGUs, there is greater uncertainty in EPA’s current
    assessment of non-EGU point-source NOx mitigation
    potential.” 81 Fed. Reg. at 74,542; see id. at 74,521.
    24
    Scientific uncertainty, however, does not excuse EPA’s
    failure to align the deadline for eliminating upwind States’
    significant contributions with the deadline for downwind
    attainment of the NAAQS.               “Questions involving the
    environment are particularly prone to uncertainty,” but “the
    statutes and common sense demand regulatory action to
    prevent harm, even if the regulator is less than certain.” Ethyl
    Corp. v. EPA, 
    541 F.2d 1
    , 24–25 (D.C. Cir. 1976) (en banc).
    As a result, “EPA [cannot] avoid its statutory obligation by
    noting [scientific] uncertainty . . . and concluding that it would
    therefore be better not to regulate at this time.” Massachusetts
    v. EPA, 
    549 U.S. 497
    , 534 (2007). It is only when “the
    scientific uncertainty is so profound that it precludes EPA from
    making a reasoned judgment” that it can excuse compliance
    with a statutory mandate. 
    Id.
     But to invoke that exception,
    EPA “must say so,” and it has not said so here. 
    Id.
    The agency also concluded that “developing a rule that
    would have covered additional sectors and emissions
    reductions on longer compliance schedules would have
    required more of the EPA’s resources over a longer rulemaking
    schedule.” 81 Fed. Reg. at 74,522. But administrative
    infeasibility, like scientific uncertainty, cannot justify the
    Update Rule’s noncompliance with the statute.
    An agency cannot “shirk[] its duties by reason of mere
    difficulty or inconvenience.” Am. Hosp. Ass’n v. Price, 
    867 F.3d 160
    , 168 (D.C. Cir. 2017). When an agency faces a
    statutory mandate, a decision to disregard it cannot be
    grounded in mere infeasibility. Rather, the agency would need
    to meet the “heavy burden to demonstrate the existence of an
    impossibility.” Sierra Club v. EPA, 
    719 F.2d 436
    , 462 (D.C.
    Cir. 1983) (quoting Ala. Power Co. v. Costle, 
    636 F.2d 323
    ,
    359 (D.C. Cir. 1979)).
    25
    EPA has not attempted to meet that burden here. True,
    EPA would need to devote “more of the EPA’s resources” in
    order to quantify good neighbor obligations from non-EGU
    sources. 81 Fed. Reg. at 74,522. And “greater uncertainty”
    about reductions from non-EGUs might render EPA’s
    calculations more inaccurate than it would prefer. Id. at
    74,542. But that does not amount to impossibility.
    EPA next contends that it should be permitted to address a
    problem incrementally, one step at a time. EPA relies on two
    of our decisions for support. First, in Grand Canyon Air Tour
    Coal. v. FAA, 
    154 F.3d 455
     (D.C. Cir. 1998), we affirmed an
    FAA rule that only partly fulfilled the agency’s statutory
    obligation to “restor[e] the natural quiet” to the Grand Canyon,
    
    id. at 460
    . We were careful to note, however, that “Congress
    had no specific timetable in mind.” 
    Id. at 477
    . The opposite is
    true here—in fact, Congress has provided a literal timetable.
    See 
    42 U.S.C. § 7511
    (a)(1). Second, in Las Vegas v. Lujan,
    
    891 F.2d 927
     (D.C. Cir. 1989), we sustained the Interior
    Secretary’s decision to list only one of two similar species of
    tortoise as endangered, observing that “agencies have great
    discretion to treat a problem partially,” 
    id. at 935
    . But the
    Endangered Species Act does not require the Secretary to list
    all endangered species by a date certain. The Clean Air Act
    requires upwind States to eliminate their significant
    contributions to downwind ozone nonattainment by prescribed
    deadlines.
    Finally, EPA cites delays occasioned by litigation. EPA
    observes that its legal obligations under the Good Neighbor
    Provision remained uncertain until the Supreme Court issued
    its April 2014 decision in EME Homer II. And this court’s
    ensuing decision in EME Homer III in July 2015 imposed
    further obligations on EPA by invalidating budgets for certain
    States. EPA released its Proposed Rule six months later, in
    26
    December 2015, and it released the Final Rule several months
    thereafter, in October 2016. In this context, litigation delays
    cannot justify EPA’s failure to bring the deadline for satisfying
    good neighbor obligations into alignment with the 2018
    attainment deadline. The timeframes do not amount to “the
    existence of an impossibility.” Sierra Club, 
    719 F.2d at 462
    .
    While EPA has not justified its failure to align the deadline
    for upwind States to eliminate significant contributions with
    the deadline for downwind areas to attain the NAAQS, the
    agency retains some flexibility in administering the Good
    Neighbor Provision. We acknowledge that the “realities of
    interstate air pollution . . . are not so simple,” and EPA faces its
    share of “thorny . . . problem[s]” in regulating it. EME Homer
    II, 572 U.S. at 514–16. EPA, though, possesses a measure of
    latitude in defining which upwind contribution “amounts”
    count as “significant[]” and thus must be abated. See id. at 518;
    520 n.21. And the Supreme Court has indicated that EPA can
    take into account, among other things, “the magnitude of
    upwind States’ contributions and the cost associated with
    eliminating them.” Id. at 518. Additionally, in certain
    circumstances, EPA can grant one-year extensions of the
    nonattainment deadlines to downwind States. 
    42 U.S.C. § 7511
    (a)(5).         EPA grants those extensions fairly
    commonly. E.g., 
    84 Fed. Reg. 44238
    , 44238 (Aug. 23, 2019);
    
    81 Fed. Reg. 26,697
    , 26,697 (May 4, 2016). And finally, EPA
    can always attempt to show “impossibility.” Sierra Club, 
    719 F.2d at 462
    .
    It also bears reemphasizing that the Update Rule set no
    deadline at all for upwind States to eliminate their significant
    contributions (a result even more infirm than the five-year
    extension struck down in North Carolina). We do not
    foreclose the possibility that the statutory command we
    construe here—that compliance with the Good Neighbor
    27
    Provision must be achieved in a manner “consistent with” Title
    I—might reasonably be read, under particular circumstances
    and upon a sufficient showing of necessity, to allow some
    deviation between the upwind and downwind deadlines. Any
    such deviation would need to be rooted in Title I’s framework,
    cf. 
    42 U.S.C. § 7511
    (a) (allowing one-year extension of
    attainment deadlines in particular circumstances), and of
    course would still need to “provide a sufficient level of
    protection to downwind States,” North Carolina, 
    531 F.3d at 912
    . What EPA cannot do, in our view, is determine that
    upwind States contribute to downwind nonattainment in a
    manner the agency deems “significant,” but then still allow
    those upwind contributions to persist out of step with the
    deadline for downwind areas to come into attainment.
    B
    Environmental Petitioners also challenge various of the
    Update Rule’s modeling and implementation choices. We are
    “at [our] most deferential” when reviewing an agency’s
    predictions and scientific determinations. Balt. Gas & Elec.
    Co. v. Nat. Res. Def. Council, Inc., 
    462 U.S. 87
    , 103 (1983).
    We find no basis to set aside the challenged determinations
    here.
    First, Environmental Petitioners challenge EPA’s
    assumption that turning on idled “Selective Catalytic
    Reduction” (SCR) controls would reduce an EGU’s emissions
    to 0.10 lbs/mmBtu. They contend that a lower rate would be
    more accurate, and they argue that EPA failed to provide a
    reasoned explanation for its choice. We conclude that EPA
    adequately explained its choice. EPA acknowledged that
    certain units could achieve a lower emissions rate with SCR,
    but determined that the higher rate was “generally achievable”
    and therefore more “appropriate” for EPA’s model, especially
    28
    because it calculated a rate on a fleet-wide basis. 81 Fed. Reg.
    at 74,544. Additionally, EPA applied a unit’s historical rate
    whenever it was lower. That explanation is “rational.” Motor
    Vehicle Mfrs. Ass’n of U.S., Inc. v. State Farm Mut. Auto. Ins.
    Co., 
    463 U.S. 29
    , 56 (1983).
    Second, Environmental Petitioners challenge EPA’s
    choice to limit its modeling to include only intrastate
    generation shifting (i.e., the shifting of electricity generation to
    cleaner power plants). Broader consideration of generation
    shifting, they argue, would have yielded greater potential
    emissions reductions. But EPA limited its modeling to
    intrastate generation shifting because it thought “broader”
    generation shifting would ignore near-term technological
    feasibility. See 81 Fed. Reg. at 74,544–45. And EPA rejected
    Environmental Petitioners’ preferred modeling approach
    because it ignored the relevance of cost thresholds, rendering it
    incompatible with an approach to modeling premised on
    uniform cost-control thresholds. See Response to Comments
    at 528, J.A. 572. Again, EPA’s choices were rational.
    Third, Environmental Petitioners challenge EPA’s
    approach to converting allowances from previous allowance
    trading programs. The Update Rule employs an allowance
    trading program, which permits underpolluting EGUs to sell
    unused allowances to overpolluting EGUs. Because this Rule
    is more stringent than prior rules, it imposes a conversion
    formula to mitigate the impact of plants losing out on
    allowances banked under prior rules. The formula results in a
    conversion ratio of approximately 3.5 old allowances per 1 new
    allowance. See 81 Fed. Reg. at 74,557.
    Environmental Petitioners say that EPA’s approach will
    create an “allowance glut” that will hinder the Rule’s salutary
    effect on upwind emissions. In their view, EPA should have
    29
    declined to allow any conversion of old allowances. EPA’s
    considered judgment, however, was that some conversion of
    allowances was necessary to respect EGUs’ legitimate
    “expectation that . . . banked allowances will have some value
    in the future of th[e] program.” Id. at 74,561. And if no
    conversion were permitted, current EGUs would have the
    incentive to use up their banked allowances all at once,
    exacerbating downwind nonattainment problems. EPA has
    demonstrated that its use of a 3.5-to-1 conversion ratio was
    reasonable.
    Environmental Petitioners last raise a statutory challenge.
    The Rule’s banked allowance program, they submit,
    contradicts EPA’s statutory obligation to implement Good
    Neighbor emissions reductions “as expeditiously as
    practicable.” 
    42 U.S.C. § 7411
    (a)(1). That challenge fails
    under Chevron. The Good Neighbor Provision does not speak
    directly to these choices. It is unclear, for example, whether
    the Provision requires a conversion ratio of 3.5 to 1, a different
    ratio, or no conversion at all. EPA’s choices are reasonable and
    merit deference. Our precedents read the Good Neighbor
    Provision to grant EPA the authority to make precisely those
    kinds of policy determinations. See, e.g., EME Homer III, 795
    F.3d at 135.
    C
    Delaware claims that it should have been designated a
    nonattaining downwind State, triggering good neighbor
    obligations from upwind States. Under EPA’s projections for
    2017, no Delaware receptors were deemed problem receptors
    because both average and maximum projected ozone
    concentrations fell below 76.0 ppb. But under the Act, upwind
    States’ SIPs—with corresponding Good Neighbor emissions
    reductions—were initially due in 2011. See 42 U.S.C.
    30
    § 7410(a)(1). Thus, Delaware argues, the Update Rule must
    use 2011 data, not 2017 data, to designate receptors as problem
    receptors. Otherwise, States upwind of nonattainment areas in
    2011 can pollute without consequence, so long as those
    downwind areas come into attainment by 2017.
    Delaware’s argument leans too heavily on the SIP
    submission deadline. SIP submission deadlines, unlike
    attainment deadlines, are “procedural” and therefore not
    “central to the regulatory scheme.” Sierra Club, 
    294 F.3d at 161
    . Nor can Delaware’s argument be reconciled with the text
    of the Good Neighbor Provision, which prohibits upwind
    States from emitting in amounts “which will” contribute to
    downwind nonattainment.        
    42 U.S.C. § 7410
    (a)(2)(D)(i)
    (emphasis added). Given the use of the future tense, it would
    be anomalous for EPA to subject upwind States to good
    neighbor obligations in 2017 by considering which downwind
    States were once in nonattainment in 2011.
    Delaware also claims that EPA impermissibly relied on
    only one year of modeling data to designate downwind
    problem receptors. That argument mischaracterizes EPA’s
    methodology. The Update Rule relies on a weighted average
    of three design values (from 2009–2011, 2010–2012, and
    2011–2013) in order to compute projected concentrations at
    each downwind receptor for 2017. See 81 Fed. Reg. at 74,532.
    Delaware’s challenge thus fails.
    III
    In contrast to Environmental Petitioners and Delaware,
    State and Industry Petitioners argue that the Update Rule—far
    from doing too little to curb interstate air pollution—
    unlawfully overregulates upwind emissions sources. They
    31
    present a smörgåsbord of arguments, which we address below.
    A
    State Petitioners contend that EPA failed to rationally
    analyze whether the environmental benefits of the Rule’s FIPs
    justified their costs, and that the agency thus contravened the
    Good Neighbor Provision and principles of administrative law.
    The Good Neighbor Provision, State Petitioners note,
    authorizes EPA to regulate emissions that “contribute
    significantly to nonattainment.” State Pet’rs’ Br. 14 (quoting
    
    42 U.S.C. § 7410
    (a)(2)(D)(i)) (emphasis in original). And in
    Michigan v. EPA, 
    213 F.3d 663
     (D.C. Cir. 2000), State
    Petitioners add, we held that EPA may consider costs in
    determining what contributions are “significant,” id. at 15
    (quoting Michigan, 
    213 F.3d at 675
    ), and endorsed the
    principle that (in the absence of a clear legislative statement to
    the contrary) a regulation’s benefits must be “at least roughly
    commensurate with [its] costs,” 
    id.
     (quoting Michigan, 
    213 F.3d 678
    –79). Accordingly, State Petitioners conclude, the
    Rule is unlawful because it irrationally subjects all regulated
    States to costly FIPs, which impose a uniform $1,400/ton
    control level on emissions sources, even if a FIP for a given
    State forecasts de minimis emissions reductions. For example,
    State Petitioners point out, the FIP that the Rule imposes on
    Wisconsin projects to reduce the state’s emissions impact on
    the sole downwind receptor to which it is linked by just two
    ten-thousandths of a part per billion.
    State Petitioners’ argument fails. As they tell it, in
    promulgating the Rule, EPA threw cost consideration to the
    wind and rashly required certain states, like Wisconsin, to
    expend great costs to achieve insignificant environmental
    benefits. But the record belies this narrative. Indeed, EPA
    settled on the Rule’s $1,400/ton control level precisely
    32
    because, the agency found, it maximized air quality
    improvement achieved per increment of additional cost. 81
    Fed. Reg. at 74550. Moreover, for states like Wisconsin, for
    which the Rule admittedly predicts relatively few emissions
    reductions, the Rule imposes relatively few costs. This is
    because—as State Petitioners themselves explain—such States
    “have already incorporated [most of] the [control] technology
    available at $1,400 or less.” States’ Reply Br. 6. In addition,
    with respect to such States, EPA determined that the Rule’s
    projected emissions reductions are significant (even if they
    appear modest relative to other regulated States’ projected
    reductions), because any State subject to the Rule is
    contributing at least one percent of the 2008 ozone NAAQS to
    at least one downwind problem receptor. For these reasons, the
    Supreme Court held that the original CSAPR, which relied on
    a virtually identical uniform control level methodology, was a
    “cost-effective . . . permissible . . . and equitable interpretation
    of the Good Neighbor Provision.” EME Homer II, 572 U.S. at
    524. State Petitioners fail to persuade us that the Update Rule
    is anything different.
    B
    State Petitioners argue next that the Rule is unlawful
    because, in quantifying upwind emissions, EPA’s source
    apportionment model included ozone from biogenic (i.e.,
    naturally occurring) sources. This contravenes the Good
    Neighbor Provision, State Petitioners contend, because the
    statute authorizes the agency to regulate only “emissions
    activity,” i.e., anthropogenic (or human-caused) emissions.
    State Pet’rs’ Br. 38 (quoting 
    42 U.S.C. § 7410
    (a)(2)(D)(i))
    (emphasis in original). State Petitioners add that EPA
    implicitly recognizes this limit on its authority, because the
    agency stated in the Rule that at step two it sought to “quantify
    33
    the contributions from anthropogenic emissions from upwind
    states.” 
    Id.
     (quoting 81 Fed. Reg. at 74,526).
    Assuming without deciding that the Good Neighbor
    Provision authorizes EPA to regulate only human-caused
    emissions,1 State Petitioners’ argument nevertheless fails. As
    EPA explains, ozone is formed when ozone precursors, such as
    NOx and VOCs, react to one another in the presence of sunlight.
    81 Fed. Reg. at 74,513. Ozone precursors are emitted from
    both anthropogenic and biogenic sources. Id. It is possible,
    therefore, for ozone to form from purely biogenic precursors,
    purely anthropogenic precursors, or a mix of both. See id. at
    74,536 n.123. State Petitioners complain that the Rule’s source
    apportionment model contravened the Good Neighbor
    Provision in classifying ozone formed from a mix of biogenic
    and anthropogenic precursors as anthropogenic ozone, which
    the Rule requires upwind States to reduce. We, however, see
    no problem with this, because ozone formed from a mix of
    biogenic and anthropogenic precursors is a product of human-
    caused emissions. True, such ozone is only partially
    anthropogenic. But Industry Petitioners point to no authority
    indicating that the Good Neighbor Provision authorizes EPA to
    regulate only emissions that are entirely attributable to human
    activity. Moreover, EPA rationally explained that it selected
    the Rule’s particular source apportionment model (as opposed
    to a model that provided a separate classification for ozone
    formed from a mix of anthropogenic and biogenic precursors)
    because, in the agency’s view, it was the more appropriate of
    the available source apportionment tools. Id. at 74,536. That
    is because it assigned culpability for downwind ozone to
    specific upwind sources of emissions in a manner that best
    advances the Good Neighbor Provision’s essential purpose of
    1
    EPA does not contest this assertion, but State Petitioners point
    to no authority that definitively establishes its truth.
    34
    curbing interstate air pollution. Id. We defer, therefore, to
    EPA’s modeling choice. Nat’l Ass’n of Mfrs. v. U.S. Dep’t of
    Interior, 
    134 F.3d 1095
    , 1103 (D.C. Cir. 1998) (“[An] agency’s
    choice of model . . . must be respected when the record
    discloses that the agency examined the relevant data and
    articulated a reasoned basis for its decision.”).2
    C
    We turn next to Industry Petitioners’ arguments that
    certain aspects of the Rule’s methodology contravene EME
    Homer II’s prohibition on overcontrol, which proscribes EPA
    from requiring a State to reduce emissions below one percent
    of the relevant NAAQS or by more than is necessary to achieve
    attainment at every downwind receptor to which a state is
    linked. EME Homer II, 572 U.S. at 521. First, Industry
    Petitioners argue that “many” downwind problem receptors
    would have attained the NAAQS had the Rule excluded
    emissions attributable to international sources. Indus. Pet’rs’
    Br. 16. Second, Industry Petitioners contend, had the Rule
    accounted for emissions reductions required of States subject
    to the Rule but not linked to a given problem receptor, a
    reviewing court would be “far likelier” to find that the Rule
    overcontrols problem receptors in general. Id. at 19. Third,
    Industry Petitioners assert, because the Rule did not reflect
    reasonably expected downwind controls, “some” of the upwind
    2
    In a related argument, State Petitioners theorize that the Rule
    double counts any ozone produced from a combination of biogenic
    and anthropogenic sources because, even if the anthropogenic half
    were to be reduced, the lingering biogenic partner would still react
    with other biogenic sources to form ozone. State Pet’rs’ Br. 38–39.
    But as EPA points out, this argument was never raised before the
    agency. EPA’s Br. 71. Because it has not been preserved, we need
    not address it. See Nuclear Energy Inst., 
    373 F.3d at 1290
    .
    35
    emissions reductions that it requires “may be unnecessary.” Id.
    at 23.
    None of Industry Petitioners’ arguments succeed. As for
    emissions from international sources, Industry Petitioners are
    simply wrong that the Rule “identif[ies] as ‘problem’ receptors
    many whose problems were actually attributable not to
    upwind-state but to non-U.S. emissions.” Indus. Pet’rs’ Br.
    16–17. That logic incorrectly assumes that an upwind State
    “contributes significantly” to downwind nonattainment only
    when its emissions are the sole cause of downwind
    nonattainment. But an upwind State can “contribute” to
    downwind nonattainment even if its emissions are not the but-
    for cause. After all, “[m]any (or perhaps all) receptors would
    also attain the NAAQS if all in-state contributions were
    eliminated, or if all upwind contributions were eliminated, or
    if     all     non-anthropogenic       contributions          were
    eliminated.” EPA’s Br. 65. Under Industry Petitioners’
    position, EPA could not require emissions reductions from any
    of those sources because each of them could point the finger at
    the others. See also Catawba County v. EPA, 
    571 F.3d 20
    , 39
    (D.C. Cir. 2009) (rejecting the argument “that ‘significantly
    contribute’ unambiguously means ‘strictly cause’” because
    there is “no reason why the statute precludes EPA from
    determining that [an] addition of [pollutant] into the
    atmosphere is significant even though a nearby county’s
    nonattainment problem would still persist in its absence”);
    Miss. Comm’n on Envtl. Quality v. EPA, 
    790 F.3d 138
    , 163
    n.12 (D.C. Cir. 2015) (observing that the argument that “there
    likely would have been no violation at all . . . if it were not for
    the emissions resulting from [another source]” is “merely a
    rephrasing of the but-for causation rule that we rejected in
    Catawba County”).
    36
    Industry Petitioners’ other arguments fail because they are
    too particularized. As we emphasized in EME Homer III, for
    challengers who raise the possibility of overcontrol in only a
    few instances, “the Supreme Court has made clear . . . that the
    way to contest instances of over-control is not through
    generalized claims that EPA’s methodology would lead to
    over-control, but rather through a ‘particularized, as-applied
    challenge.’” Homer III, 795 F.3d at 137 (quoting EME Homer
    II, 
    572 U.S. 523
    –24). Accordingly, as we did when presented
    with similar arguments in EME Homer III, we reject Industry
    Petitioners’ arguments because they do no more than speculate
    that aspects of “EPA’s methodology could lead to over-control
    of upwind States.” 
    Id.
     at 136–37.
    D
    As noted in Part I, supra, in order to implement upwind
    States’ good neighbor obligations, EPA devised a detailed
    process to determine whether downwind pollution receptors
    were in attainment, maintenance, or nonattainment status.
    Under this framework, EPA identified thirteen maintenance
    receptors. 81 Fed. Reg. at 74,533. Nine of those thirteen
    measured in attainment, in that their most recent monitored
    design value complied with the NAAQS. Id. Four upwind
    States—Iowa, Kentucky, Tennessee, and Wisconsin—were
    linked exclusively to one or more of those nine maintenance
    receptors. Id. at 74,538–39.
    Industry Petitioners take two jabs at the Update Rule’s
    definition of “maintenance” receptors and its treatment of
    States linked exclusively to them. First, they say EPA deviated
    unreasonably from past agency practice in designating
    receptors as maintenance, even when they monitored in
    attainment. Second, they claim that imposing a single uniform
    $1,400/ton control level on all upwind States necessarily leads
    37
    to overcontrol of those States linked exclusively to
    maintenance receptors. See Indus. Pet’r’s Br. 8–15, 25–26.
    Neither argument succeeds.
    1
    Industry Petitioners accept, as they must, that EPA was
    permitted to base its designations, at least in part, on
    predictions about the state of air quality in 2017. See North
    Carolina, 
    531 F.3d at
    913–14 (affirming as reasonable EPA’s
    interpretation of “will” in the Good Neighbor Provision as
    “indicat[ing] the future tense”).
    Industry Petitioners’ first objection is that the agency’s
    exclusive reliance on projections constitutes an unreasonable
    deviation from its past practice of relying on a combination of
    modeled and monitored data. 
    63 Fed. Reg. 57,356
    , 57,375
    (Oct. 27, 1998) (NOx SIP Call) (relying on both monitored and
    modeled data); accord 
    70 Fed. Reg. 25,162
    , 25,241 (May 12,
    2005) (CAIR); cf. 
    76 Fed. Reg. 48,208
    , 48,230 (Aug. 8, 2011)
    (explaining that EPA had to “drop[]the ‘monitored’ part of the
    modeled + monitored test” only because “the most recent
    monitoring data” reflected effects of the unlawful Clean Air
    Interstate Rule).
    Our decision in North Carolina squarely forecloses that
    argument, and its reasoning fully explains the agency’s
    purported switch to reliance only on projected air quality. The
    Good Neighbor Provision directs EPA to regulate emissions
    that both “contribute significantly to nonattainment,” and also
    “interfere with maintenance,” of air quality standards. See 
    42 U.S.C. § 7410
    (a)(2)(D)(i); North Carolina, 
    531 F.3d at
    909–
    10. In North Carolina, EPA had interpreted the Good
    Neighbor Provision’s maintenance prong narrowly, as ensuring
    only against retrogression by previously nonattaining
    38
    receptors. 
    Id. at 910
    . This court overturned that interpretation
    because it failed to give “independent effect” to the “interfere
    with maintenance” prong, leaving those areas “barely meeting
    attainment” without any “recourse” against upwind States’
    contamination of their air quality. Id.; accord EME Homer II,
    572 U.S. at 516 n.18 (describing EPA’s duty to “reduce”
    emissions from upwind States sufficient to ensure that “an
    already-attaining State [maintains] satisfactory air quality”)
    (emphasis added); EME Homer III, 795 F.3d at 136
    (explaining that EPA rule “afford[ed] independent effect to the
    ‘interfere with maintenance’ prong”).
    EPA’s Rule does what the rule in North Carolina did not.
    It gives effect to the upwind States’ independent duty not to
    impede downwind States’ maintenance of air quality standards.
    As EPA explained, “the possibility of failing to maintain the
    NAAQS in the future, even in the face of current attainment of
    the NAAQS, is exactly what the maintenance prong of the good
    neighbor provision is designed to guard against.” 81 Fed. Reg.
    at 74,531. So the Rule’s designation method for maintenance
    receptors was reasonable, and its decision to change its
    approach to protect receptors in maintenance status was a
    sensible response to North Carolina’s requirement that EPA
    give full effect to the statute’s distinct maintenance command.
    See 
    42 U.S.C. § 7410
    (a)(2)(D)(i).
    As for State Petitioners’ insistence that EPA should have
    relied on a combination of monitored and modeled data, that
    argument overlooks that the agency’s projections were
    predicated     directly    upon      monitored    data    from
    2009–2013. See 81 Fed. Reg. at 74,532. Any standard more
    demanding—a requirement, for example, that maintenance
    receptors actually monitor in nonattainment between
    2013–2015—would run headlong into North Carolina’s
    directive that EPA give “independent effect” to the
    39
    maintenance prong.       North Carolina, 
    531 F.3d at 909
    .
    2
    As previously noted, EPA applied a uniform cost threshold
    of $1,400/ton to identify necessary emission reductions in
    contributing upwind States. In other words, the Rule requires
    that States deploy all available technologies capable of
    reducing emissions at a cost of $1,400 or less per ton of NOx
    reduced. 81 Fed. Reg. at 74,541.
    Industry Petitioners contend that this uniform control
    threshold led to overcontrol in the four States linked
    exclusively to maintenance receptors (rather than to receptors
    showing nonattainment).          Indus. Pet’rs’ Br. 25–26.
    Specifically, after EME Homer II, the maintenance prong only
    authorizes EPA to “limit emissions ‘by just enough to permit
    an already-attaining State to maintain satisfactory air quality.’”
    EME Homer III, 795 F.3d at 137 (quoting EME Homer II, 572
    U.S. at 515 n.18).
    Industry Petitioners say the agency’s approach ran afoul of
    that mandate in two interrelated ways. First, for States linked
    exclusively to maintenance-only receptors, they argue that their
    existing upwind emission levels are by definition compatible
    with attainment in the downwind States, so that any additional
    reductions beyond “existing . . . levels” constitute overcontrol.
    Indus. Pet’rs’ Br. 26. Second, Industry Petitioners contend
    that, as a conceptual matter, if the $1,400/ton control level were
    sufficient to resolve issues at nonattainment receptors, then that
    same standard would, by definition, lead to overcontrol of
    those States linked exclusively to maintenance receptors. Id.
    at 25–26.
    40
    Both arguments fail because they ignore key aspects of the
    agency’s reasoning. Industry’s insistence that current levels
    suffice for maintenance wrongly assumes that maintenance
    receptors will violate the NAAQS only if upwind emissions
    increase beyond the existing baseline. But things are not that
    simple. Variations in atmospheric conditions and weather
    patterns can bring maintenance receptors into nonattainment
    even without elevated emissions. See 81 Fed. Reg. at 74,513–
    14, 74,532, 74,537–38.
    Likewise, the argument that the uniform control standard
    necessarily overshoots for maintenance receptors presupposes
    that the Update Rule fully satisfies upwind States’ Good
    Neighbor responsibilities. Not so—as the Rule repeatedly self-
    describes, it is only a partial remedy. See, e.g., 81 Fed. Reg. at
    74,505, 74,508, 74,520–22.
    More fundamentally, as we discussed with respect to
    Industry Petitioners’ over-particularized claims of overcontrol,
    these arguments fail to identify a single “actual . . . instance[]
    of over-control,” which is what EME Homer II calls for. EME
    Homer III, 795 F.3d at 137 (emphasis added) (interpreting
    EME Homer II, 572 U.S. at 523–24). In the Update Rule, EPA
    conducted a rigorous overcontrol analysis, and concluded that
    even with the new $1,400/ton control level, only a small subset
    of maintenance and nonattainment receptors were projected to
    succeed in fully resolving their air quality problems. See 81
    Fed. Reg. at 74,551–74,552. Of all the upwind States, only
    Tennessee was linked exclusively to those fully resolved
    receptors. Id. And even then, the agency confirmed that
    problems at Tennessee’s linked receptors could not be resolved
    at a less stringent level of control. Id. As this record illustrates,
    where evidence of “actual” overcontrol is needed, Industry
    Petitioners’ conceptual objections alone cannot suffice. See
    EME Homer II, 572 U.S. at 515 n.18.
    41
    E
    State Petitioners challenge EPA’s use of a grid-cell
    approach for identifying maintenance and nonattainment
    receptors. State Pet’rs’ Br. 24–29. EPA uses that method to
    calculate a monitor’s relative response factor. It does so by
    putting the monitor at the center of a twelve-square-kilometer
    grid, which consists of nine four-square-kilometer cells, and
    then analyzing the air quality in each of the individual cells. 81
    Fed. Reg. at 74,526–27. For “coastal” monitors near the ocean,
    the grids included “offshore” cells in the air quality
    measurements. See id. at 74,534.
    State Petitioners claim that these offshore cells artificially
    inflated projected ozone concentrations at the coastal monitors,
    and that Iowa and Wisconsin were linked exclusively to those
    misidentified air quality strugglers. State Pet’rs’ Br. 24–29; 81
    Fed. Reg. at 74,534, 74,538–39 (Tables V.E-2, V.E-3). In the
    States’ view, EPA should have based its designation decisions
    on data derived solely from the cell in which the monitor was
    located or from all of the over-land cells within the grid. State
    Pet’rs’ Br. 24–29.
    That objection fails for four reasons.
    First, the agency offered a reasonable explanation for why
    its grid-cell approach was “most representative” of onshore
    ozone concentration levels. For starters, these models can be
    imprecise at the “grid cell level”—that is, small variations in
    the model may influence whether ozone is shown to form in
    one particular cell rather than its neighbor. 81 Fed. Reg. at
    74,534. That precision problem is further compounded by the
    fact that monitors are often located close to the border of
    several cells. Id. Taking those two problems into account, the
    agency reasonably worried that it would miss data “most
    42
    representative” of ozone concentrations, if it were to disregard
    high concentrations in neighboring cells and focus exclusively
    on the individual monitor cell. See id.; EME Homer III, 795
    F.3d at 135 (describing the considerable “deferen[ce]” owed to
    agency “modeling choices”).
    Second, EPA found that over-water ozone often blows
    onto the land above coastal monitors, and so capturing that
    input is critical to accurately gauging air quality in the monitor
    area. 81 Fed. Reg. at 74,534; North Carolina, 
    531 F.3d at 925
    (affording “substantial deference to EPA’s technical
    expertise”).
    Third, the accuracy of EPA’s judgment is confirmed by the
    fact that, even under State Petitioners’ single-cell approach, the
    lone receptor to which Iowa and Wisconsin are linked would
    still demonstrate maintenance, and thus a need to preserve that
    status. Cf. 81 Fed. Reg. at 74,534–35. Having pressed the
    single-cell approach on the agency, State Petitioners cannot
    seriously complain about a methodology that produced a
    functionally identical result.
    Fourth, trying a different tack, State Petitioners latch onto
    Michigan v. EPA’s command that the agency regulate only
    “onshore state nonattainment.” 
    213 F.3d at 681
    . But
    Petitioners omit critical context. In Michigan, we struck
    Wisconsin’s inclusion in a downwind attainment plan because
    EPA had shown only that Wisconsin contributed significantly
    to nonattainment in Lake Michigan itself. The record did not
    reveal a downwind contribution to “any other State[.]” 
    Id. at 681
     (quoting 
    42 U.S.C. § 7410
    (a)(2)(D)(i)(I)). The fatal blow
    for EPA’s approach was when the agency “conceded” at oral
    argument that it had provided no record “explanation to
    support” a linkage “between the Lake Michigan receptor area
    and the onshore states.” 
    Id.
     (internal quotation marks omitted).
    43
    EPA was careful not to make that same mistake a second
    time. So here, EPA explained carefully and on the record how
    data from those offshore cells could be reasonably probative of
    air quality at any given coastal receptor. See 81 Fed. Reg. at
    74,534. Michigan is not the categorical bar Petitioners
    describe, and EPA’s approach was fully consistent with its
    holding.3
    F
    Industry Petitioners next complain that EPA failed to fully
    consider the emissions-reducing effects of a 2016 Pennsylvania
    rule. Indus. Pet’rs’ Br. 17–18. That argument falls wide of the
    mark.
    EPA took into account State-level efforts to reduce
    emissions when forecasting 2017 air quality during the
    rulemaking process. But for reasons of modeling-reliability,
    EPA included only those State emissions rules in effect through
    February 1, 2016. 81 Fed. Reg. at 74,528 n.108. That was
    EPA’s “cutoff date” because, after February 1, 2016, “it
    [would] no longer [be] possible to incorporate updates into the
    input databases” before EPA had to run the model. Id.
    3
    In a footnote, Industry Petitioners argue that Arkansas,
    Mississippi, and Pennsylvania were also negatively affected by the
    inclusion of offshore cells because those States were linked to
    monitors located in close proximity to large bodies of water. Indus.
    Pet’rs’ Br. 29 n.15. But that lone, underdeveloped footnote does not
    even show whether these States were actually impacted by the
    agency’s methodology. In any event, “cursory arguments made only
    in footnotes” generally do not preserve an issue, and there is no
    reason to make an exception here. Abdelfattah v. U.S. Dep’t of
    Homeland Sec., 
    787 F.3d 524
    , 532 (D.C. Cir. 2015) (formatting
    modified).
    44
    In April 2016—several months after that cutoff date—
    Pennsylvania finalized a rulemaking to implement
    “Reasonably Available Control Technology” (“Control
    Technology”) that was designed to limit the emission of NOx
    and VOCs. That rule was scheduled to be implemented on
    January 1, 2017, almost a year after EPA’s modeling window
    had closed.
    While unable to include the Pennsylvania rule in its
    modeling, EPA acknowledged its potential magnitude, and so
    chose to conduct a “robust separate analysis to evaluate [the
    Control Technology’s] impacts.” EPA, Memorandum on
    Pennsylvania Rulemaking, J.A. 463. That study concluded that
    the Pennsylvania rule did “not affect EPA’s identification of
    [any] nonattainment or maintenance receptors.” 
    Id.,
     J.A. 465.
    Industry Petitioners now fault the agency for considering
    only the rule’s effect on NOx emissions, while ignoring its (far
    more modest and unquantified) effect on emissions of VOCs.
    That argument is a nonstarter. First off, Industry Petitioners
    fail to explain how the agency could have figured reductions in
    VOCs emissions into its analysis since the Pennsylvania rule
    makes no effort to quantify them.
    Anyhow, the regulated electric utilities, which account for
    the majority of the Control Technology’s emission reductions,
    were projected to emit almost sixty times more NOx than VOCs
    in the absence of the Pennsylvania rulemaking. Given that
    even the reductions in NOx had no appreciable effect on EPA’s
    receptor designations, it was perfectly reasonable for the
    agency to conclude that factoring in the even more nominal
    effects of VOCs regulation would not be worth the candle. Cf.
    Thompson v. Clark, 
    741 F.2d 401
    , 408 (D.C. Cir. 1984) (The
    Administrative Procedure Act “has never been interpreted to
    45
    require the agency to . . . analyse [sic] every . . . alternative
    raised by the comments, no matter how insubstantial.”). For
    those reasons, EPA’s decision was well within legal bounds.
    G
    Industry Petitioners lodge several objections to EPA’s
    methodology for calculating States’ emissions budgets. But a
    comprehensive picture of the agency’s approach exposes
    where those arguments fall short.
    EPA’s $1,400/ton control level reflects the costs
    associated with turning on idled selective catalytic reduction
    equipment, as well as with the installation of “state-of-the-art
    combustion controls,” like “low-NOx burners” and “over-fire
    air.” 81 Fed. Reg. at 74,541.4 EPA used an Integrated Planning
    Model (“Integrated Model”) that simulated the electricity
    market to project both (i) a “baseline case” of what 2017
    emissions would be without any additional pollution controls,
    id. at 74,528, 74,532; and (ii) a “control case” that incorporated
    the selective catalytic reduction and combustion control
    equipment, see id. at 74,541, 74,548–49 (Tables VI.C-1-2).
    In setting a given State’s emissions budget, the agency
    took the difference between the baseline and control cases—
    what it calls the “relative-rate delta”—and subtracted it from
    the State’s actual 2015 emission rate. 81 Fed. Reg. at 74,547–
    48. That emissions rate—expressed in terms of pounds of NOx
    per one million British thermal units of emitted heat
    (“lbs/mmBtu”)—was then multiplied by the State’s 2015 heat
    4
    Selective catalytic reduction takes place when a reagent is
    injected into a pollutant gas flue, inducing a chemical reaction that
    transforms the pollutant into a more palatable chemical or chemicals.
    See J.A. 1462–66.
    46
    input to produce the individual State emissions budget. Id. at
    74548–49 (Tables VI.C-1-2). Industry Petitioners challenge
    several steps in the analysis, but none of their arguments
    succeed.
    First, they claim that EPA was unrealistic to expect that
    the relevant emission controls could be fully installed during
    the less-than-eight-month period between when the Update
    Rule was finalized and when it was set to take effect. They say
    at least eighteen months is needed, citing supporting anecdotes.
    But all those anecdotes show is that installation can drag
    on when companies are unconstrained by the ticking clock of
    the law. That does not establish how much time is technically
    required to complete installation. EPA reasonably based its
    determination on a real-world example identified during an
    earlier rulemaking. Industry Petitioners fail to explain, by
    reference to the actual mechanics of installation, why that EPA
    judgment was so plainly wrong as to demonstrate arbitrary,
    capricious, or unreasoned decisionmaking. In what is
    effectively a war of competing anecdotes, EPA wins because
    “we are forbidden from substituting our judgment for that of
    the agency.” Ass’n of Am. R.R.s v. Interstate Commerce
    Comm’n, 
    978 F.2d 737
    , 740 (D.C. Cir. 1992) (formatting
    modified).
    Second, Industry Petitioners take issue with EPA’s
    “idling” assumption—that is, the proposition that certain less
    efficient electric generating units would temporarily cease
    operations once energy supply exceeds demand. Indus. Pet’rs’
    Br. 23–24. By way of background, Industry Petitioners raised
    concerns, during the comment period, that the agency’s model
    assumed an unrealistic number of imminent unit retirements.
    In response, EPA promised to “constrain[ ] the model to
    prevent . . . retirement projections” before 2020. J.A. 361. The
    47
    Integrated Model nevertheless assumed that certain units
    would be “idled” whenever supply outstrips demand.
    According to Industry Petitioners, treating those units as idled
    “amount[s] to the same thing” as deeming them permanently
    retired from production. Indus. Pet’rs’ Br. 24.
    That argument mixes apples and oranges. Idling is a
    natural component of modeling programs, like the Integrated
    Model, that are designed to reflect electricity markets “as
    accurately as possible.” 81 Fed. Reg. at 74,528. To capture
    actual market mechanics, the model determines the least-cost
    method of anticipating electricity demand over a given period,
    and it assumes that less efficient units will be “idled” in the
    short run when they are not needed to meet demand. That
    temporary, on-again-off-again idling is quite distinct from
    permanent retirement and closure of a facility. That a model
    overestimates the rate of long-run retirements thus says nothing
    about whether it accurately projects the ebb and flow of short-
    run supply and demand. So EPA’s decision to limit near-term
    retirement projections based on long-run unprofitability says
    nothing about the use of temporary, market-driven idling in its
    economic models.
    Industry Petitioners supplement with an argument that
    EPA failed to fully explain its idling assumption on the record.
    Indus. Reply Br. 12. But that is neither here nor there, because
    Industry Petitioners make no showing that the idling
    assumption actually altered State emissions budgets. EPA used
    the Integrated Model only to determine the delta between a
    State’s baseline case and the control case, which it then applied
    to the State’s historical 2015 emission rates. Because any
    projected idling was held constant between the baseline case
    and the control case, it could not affect how much units were
    expected to reduce their emissions relative to their historical
    baseline. Cf. 81 Fed. Reg. at 74,547.
    48
    Third, Industry Petitioners claim the agency promised to
    treat .1 lbs/mmBtu as a ceiling on the emissions-reduction
    potential for units equipped with selective catalytic reduction.
    But instead the agency sometimes assumed rates as low as .075
    lb/mmBtu in its actual emission-budget analysis. Indus. Pet’rs’
    Br. 24–25. That argument does not stand up to scrutiny.
    EPA initially proposed calculations based on the
    assumption that selective catalytic reduction-equipped units
    could achieve a NOx emissions level of .075 lbs/mmBtu. See
    81 Fed. Reg. at 74,544. In the Final Rule, EPA required a less-
    demanding threshold for Industry of .1 lbs/mmBtu. Id. at
    74,543. At the same time, EPA had learned during the
    comment period that certain, newer plants had a proven track
    record of achieving superior emissions rates. So EPA decided
    in the Final Rule that those units would be assigned their
    historical rate if lower than .1 lbs/mmBtu. That decision not to
    license plants with better emission controls to emit more NOx
    than they already do was eminently reasonable.
    In a related argument, Industry Petitioners complain that
    EPA applied its .075 lbs/mmBtu limit for selective catalytic
    reduction-controlled units that share “common stacks” with
    uncontrolled units. Indus. Pet’rs’ Br. 24. But these common
    stack arrangements prevent the agency from gathering “reliable
    data to determine the emission rates of the individual units.”
    J.A. 461. EPA therefore adopted a .075 lbs/mmBtu estimate in
    both the base and control cases, effectively concluding that
    those units equipped with selective catalytic reductions were
    incapable of “achiev[ing] any additional reductions.” J.A.
    461–62.
    Because that emissions-reduction capacity was held
    constant between the base and control measures, Industry
    49
    Petitioners have failed to show how the statutory or regulatory
    scheme required EPA to take a different approach to dealing
    with the lack of empirical data from combined stacks. Nor did
    they show how the underlying emissions rate could have
    affected the delta EPA relied on in calculating a State’s
    emissions-reduction potential, given that the reduction was
    held constant. EPA’s Br. 87–88; cf. 81 Fed. Reg. at 74,547.
    IV
    A
    Industry Petitioners challenge the emissions budgets for
    Mississippi, Oklahoma, Indiana, and Illinois, as well as several
    specific emissions-allowance allocations to units in those
    States. The gist of the argument is that the complaining States
    want larger emissions budgets, and the complaining units want
    a larger share of those budgets in the form of increased
    allowances. But a majority of these challenges arise in direct
    response to EPA’s decision in the Final Rule to use the relative-
    rate method in calculating emissions limits. And because that
    methodological change was introduced for the first time in the
    Final Rule and the decision to adopt it was made in response to
    comments, 81 Fed. Reg. at 74,547–48; J.A. 419, Industry
    Petitioners’ challenges to the relative-rate method are not yet
    ripe for judicial review. See 
    42 U.S.C. § 7607
    (d)(7)(B).
    The Clean Air Act requires, as a predicate for judicial
    review, that EPA first be afforded the opportunity to address
    objections to its rules, and that those objections be raised with
    “reasonable specificity during the period for public comment.”
    
    42 U.S.C. § 7607
    (d)(7)(B). Where “it was ‘impracticable to
    raise a particular objection’ or if ‘the grounds for the objection
    arose after that [comment] period,’” the party challenging the
    agency action “still must petition EPA for administrative
    50
    reconsideration before raising the issue before this Court.”
    EME Homer III, 795 F.3d at 137 (quoting 
    42 U.S.C. § 7607
    (d)(7)(B)).      Should EPA choose not to grant
    reconsideration, that decision is independently reviewable. Id.;
    
    42 U.S.C. § 7607
    (d)(7)(B).
    So no matter how EPA responds, a petition for
    reconsideration is “what the statute requires and what [this
    court] therefore must insist upon,” even if it might “seem a
    roundabout” way of doing things. EME Homer III, 795 F.3d at
    137. After all, we cannot fairly review how the agency
    responded to an argument that was never presented to it. See
    Smith v. Berryhill, 
    139 S. Ct. 1765
    , 1779 (2019) (“Fundamental
    principles of administrative law . . . teach that a federal court
    generally goes astray if it decides a question that has been
    delegated to an agency if that agency has not first had a chance
    to address the question.”); see also Util. Air Regulatory Grp. v.
    EPA, 
    744 F.3d 741
    , 747 (D.C. Cir. 2014) (“[T]he only
    objections that may immediately be raised upon judicial review
    are those that were raised during the public comment period.
    Objections raised for the first time in a petition for
    reconsideration must await EPA’s action on that petition.”).
    That administrative exhaustion requirement is “strictly”
    enforced. Nat. Res. Def. Council v. EPA, 
    571 F.3d 1245
    , 1259
    (D.C. Cir. 2009) (per curiam).
    Industry Petitioners run headlong into this exhaustion
    requirement when they complain that Oklahoma’s and
    Mississippi’s emissions in the agency’s 2017 base cases far
    exceeded those States’ actual 2015 emissions. Those inflated
    bases, they say, translated into unrealistically low emissions
    budgets for both States. Indus. Pet’rs’ Br. 36, 39–40. EPA
    responds that its methodology neutralizes any errors that might
    have caused those distortions by holding constant, between the
    base and control cases, those erroneous inputs that caused the
    51
    purported inflation in the base. EPA’s Br. 89, 96–97. Industry
    Petitioners beg to differ, asserting that the artificial inflation is
    not, in fact, neutralized or cancelled out because: (i) if the base
    and control cases are multiplied, then the delta between the two
    will increase; and (ii) the marginal cost of emissions reduction
    goes up as overall emissions go down, see Indus. Reply Br. 17–
    18.
    The questions of whether, and the extent to which, the
    relative-rate method actually neutralizes distortions are not
    properly before us. Because the challenged methodology first
    appeared in the Final Rule, Industry Petitioners’ arguments
    should have been raised in a petition for agency
    reconsideration. Just like EME Homer III, this court is
    “without authority” to decide a challenge that petitioners “did
    not and could not have raised . . . during the period for public
    comment.” 795 F.3d at 137. Instead, agency reconsideration
    is “the only appropriate path” forward. Id. (emphasis added).
    Presumably that exhaustion requirement is why at least two of
    the Industry Petitioners have already sought agency
    reconsideration.5 Until EPA acts on those reconsideration
    petitions, the challenges are not yet ripe for our review. Id.; cf.
    5
    See Oklahoma Gas and Electric Company, Petition for
    Reconsideration, EPA–HQ–OAR–2015–0500–0589, at 5 (“Because
    the 2017 budget-setting base case was unrealistically high, the ‘delta’
    between that number and the 2017 cost threshold was also too
    high.”), https://www.regulations.gov/document?D=EPA-HQ-OAR-
    2015-0500-0589; id. (explaining that “[i]t was impossible . . . to
    comment on EPA’s revised emissions budget calculation
    methodology” because it “was first presented . . . in the Final Rule”)
    (emphasis added); Western Farmers Electric Cooperative, Petition
    for Reconsideration, EPA–HQ–OAR–2015–0500–0588, at 4
    (describing the relevant disparity as the “Perverse IPM Result”)
    (emphasis in original), https://www.regulations.gov/document?
    D=EPA-HQ-OAR-2015-0500-0588.
    52
    Appalachian Power Co. v. EPA, 
    135 F.3d 791
    , 818 (D.C. Cir.
    1998) (per curiam) (“The purpose of the exhaustion
    requirement is to ensure that the agency is given the first
    opportunity to bring its expertise to bear on the resolution of a
    challenge to a rule.”). And those Petitioners who have not yet
    moved for reconsideration run into that same bar on judicial
    review. EME Homer III, 795 F.3d at 138.
    The arguments by Energy Association and Indiana Utility
    Group (“Indiana Petitioners”) meet the same fate. They
    complain that (i) the relative-reduction method yielded a
    budget far below the one proposed under EPA’s initial formula;
    and (ii) EPA’s reliance on 2015 heat-input data, rather than the
    2014 data cited in the proposed rule, harmed Indiana units
    because the State’s heat input fell considerably between the
    two years. Indus. Pet’rs’ Br. 31.
    Petitioners, of course, enjoy no special entitlement to
    either the initial emissions figure or the less-current data
    referenced in the proposed rule. And to the extent that the
    Indiana Petitioners mean to challenge the reasonableness of the
    relative-rate method or the representativeness of the 2015 data,
    those empirically laden propositions must first be exhausted in
    a motion for reconsideration. Cf. Weinberger v. Salfi, 
    422 U.S. 749
    , 765 (1975) (“Exhaustion is generally required as a matter
    of preventing premature interference with agency processes, so
    that the agency may function efficiently and so that it may have
    an opportunity to correct its own errors, to afford the parties
    and the courts the benefit of its experience and expertise, and
    to compile a record which is adequate for judicial review.”).6
    6
    Indiana Petitioners recognize this implicitly when, in a single
    sentence in their reply brief, they suggest that EPA was required to
    resubmit its relative-reduction methodology for additional comment.
    53
    The Indiana Petitioners’ remaining contentions do not
    advance the ball. They criticize EPA’s decision to assign
    emissions rates between .07 and .075 lb/mmBtu to units newly
    equipped with selective catalytic reduction, even though those
    technologies had not yet been put into operation in 2015 and
    2016. Indus. Pet’rs’ Br. 32 & n.30. But EPA reasonably
    assumed that these technologies would be in use when the Rule
    took effect in 2017, and so EPA assigned these units an
    emission rate of .075 lbs/mmBtu to “reflect” the full effects of
    the new technology. J.A. 420. As for the .07 lbs/mmBtu rate,
    the figure was used not to adjust the State’s 2015 emissions
    data, but rather to calculate its relative-rate delta. EPA claims
    that, because it was assigned in both the base and control cases,
    the method neutralized any inflating effect. EPA’s Br. 94 n.24.
    If Petitioners have any colorable quibble, it is with the
    proposition that the relative reduction methodology neutralizes
    the effects of mistaken inputs. And as we have said, that
    argument must first be raised in a motion for reconsideration.
    B
    Industry Petitioners from Oklahoma and Illinois challenge
    other aspects of EPA’s budget and unit allocation decisions.
    Their arguments are no more successful.
    As previously explained, EPA computed unit allocations
    based on a plant’s projected share of its State’s overall ozone-
    season heat input, capped at the unit’s actual emissions
    between 2011 and 2015. 81 Fed. Reg. at 74,562. In setting that
    But Petitioners have forfeited this cursory reframing of the argument
    by failing to raise it until their reply brief. See World Wide Minerals,
    Ltd. v. Republic of Kazakhstan, 
    296 F.3d 1154
    , 1160 (D.C. Cir.
    2002).
    54
    cap, EPA relied principally upon measured data reported
    directly by industry to the agency under 40 C.F.R. Part 75,
    Subpart G. “Where EPA data [were] unavailable,” the agency
    said it would also rely on data from the United States Energy
    Information Administration. J.A. 260.
    Western Farmers Electric Cooperative, one of the
    Oklahoma Industry Petitioners, complains that, for certain
    units, EPA relied on just one year of available reported data,
    and refused to fill in the gaps with data from the Energy
    Information Administration. Indus. Pet’rs’ Br. 40–42. This,
    they claim, was contrary to the purpose of EPA’s multi-year
    averaging approach, which was designed to avoid aberrations
    and to best approximate each unit’s true heat input. Indus.
    Reply Br. 21.
    The Cooperative is mistaken. EPA reasonably prioritized
    its own data, which “relies on unmodified historic data reported
    directly by the vast majority of covered sources, whose
    designated representatives have already attested to [its]
    validity.” 76 Fed. Reg. at 48,288. In deciding whether to use
    the Energy Information Administration’s estimates to fill in the
    gaps, EPA faced a tradeoff between accuracy, on the one hand,
    and long-run representativeness, on the other. We see no
    reason to disturb the balance that EPA struck. Cf. Catawba
    County, 
    571 F.3d at 41
     (describing the “extreme degree of
    deference [given] to [EPA] when it is evaluating scientific data
    within its technical expertise”) (formatting modified).
    In an effort to evade that deference, the Cooperative
    frames its challenge as the agency “[d]eparting” from its own
    internal standards. Indus. Pet’rs’ Br. 40–41. But absent
    evidence that the agency ever committed to or even applied the
    Cooperative’s preferred approach, the deviation claim falls flat.
    55
    Last, Prairie State Generating Company (“Prairie State”),
    an Illinois-based petitioner, claims it was unfairly
    disadvantaged by EPA’s unit classification system. Indus.
    Pet’rs’ Br. 29–30. That system divided units into two general
    categories: “existing” and “new.” 81 Fed. Reg. at 74,564–65
    (describing also a third category for new units in Indian
    country, not at issue here). Over ninety percent of each State’s
    budget went to “existing units”—that is, those units that started
    operation prior to January 1, 2015, and for which EPA
    possessed at least one year of measured emissions data. 81
    Fed. Reg. at 74,564.
    By comparison, “new units” are ones for which EPA lacks
    even this first year’s worth of data. Because the agency lacked
    reliable emissions data on these new units, it established a new-
    unit “set-aside” for each State. EPA calculated it based on (i)
    a uniform two percent baseline, which “reflect[s] a reasonable
    upper bound of state-level share of emissions from new units;”
    and (ii) state-specific additions based on amounts that EPA
    “projects to be emitted from ‘planned’ units in 2020.” J.A. 257.
    Should new-unit allowances go unallocated, they are then
    redistributed to existing units before the relevant compliance
    deadline. 81 Fed. Reg. at 74,565. Relatedly, EPA shifts to the
    set-aside all allowances from units that have ceased operations
    for over five years. Id. This five-year-long dormancy
    requirement was necessary because a sudden loss of
    allowances might “cause a unit, which would otherwise retire,
    to continue operations in order to retain ongoing allowance
    allocations.” Id. at 74,566.
    Prior rulemaking had defined Prairie State as a “new” unit.
    But by January 2015, when it was well into “normal
    operations,” it was reclassified as an “existing unit” under the
    Update Rule, with allocation based upon its actual heat input.
    Indus. Pet’rs’ Br. 28–29.
    56
    Prairie State’s principal complaint is that it would have
    been able to enjoy the benefits of new-unit set asides if it were
    classified as a new, rather than an existing, unit. See Indus.
    Pet’rs’ Br. 29–31. But a preference for more youthful
    treatment is not a legal argument. In 2011, during the prior
    rulemaking, Prairie State was new; five years later, not so
    much.
    Prairie State’s various ancillary contentions amount to no
    more than explanations for why it would have been better off
    if EPA had deviated from its even-handed approach and treated
    it as a new unit, despite its several years of operation. To the
    extent Prairie State is attacking, indirectly, the Rule’s definition
    of “new units” or its allocation for retiring units, both of those
    agency choices were reasonable and sufficiently explained. 81
    Fed. Reg. at 74,565. Because “new units” were defined as
    those for which EPA lacks a single year’s worth of reliable
    emissions data, EPA necessarily could not rely on actual
    emissions data to make an allocation. J.A. 256. And a set aside
    for retiring units was necessary to ensure that the allowance
    allocations did not have the perverse incentive of deterring
    retirement. 81 Fed. Reg. at 74,566.7
    7
    Prairie State’s challenge to EPA’s budget-setting decision is
    equally fruitless. According to Prairie State, EPA deflated Illinois’
    budget allocation by averaging Prairie State’s highest heat inputs
    between 2011 and 2015, which were “artificially low due to issues
    with [Prairie State’s] advanced technology.” Indus. Pet’rs’ Br. 29.
    But Prairie State’s first premise is wrong. EPA relied only on the
    State’s most recent measured data from 2015, not the three-year
    average, in setting State budgets. 81 Fed. Reg. at 74,547. And by
    Prairie State’s own admission, it “began normal operations in 2014.”
    Indus. Pet’rs’ Br. 28. There was neither error nor discernible
    prejudice to Prairie State in that budget-setting decision.
    57
    To make that long story short, all of the Industry
    Petitioners’ State- and unit-specific arguments fail.
    V
    State Petitioners offer up a pair of procedural challenges
    to the Rule. But both claims suffer fatal jurisdictional defects.
    First, Texas, Ohio, and Wisconsin claim that EPA sat on
    their timely SIP submissions beyond the twelve-month
    statutory deadline, see 
    42 U.S.C. § 7410
    (k)(2), so that it could
    develop the data and methodology necessary to justify rejecting
    the SIPs and to impose FIPs in their place. State Pet’rs’ Br.
    29–38; see 
    81 Fed. Reg. 53,309
     (Aug. 12, 2016) (disapproval
    of Wisconsin SIP); 
    81 Fed. Reg. 53,284
     (Aug. 12, 2016)
    (disapproval of Texas SIP); 
    81 Fed. Reg. 38,957
     (June 15,
    2016) (disapproval of Ohio SIP). They ask that we vacate the
    Rule and instruct the agency to revisit these SIPs based
    exclusively upon data acquired before the Section 7410(k)
    deadline. State Pet’rs’ Br. 37–38.
    Those arguments are, in effect, collateral attacks on EPA’s
    SIP denials—and they come too late in the game. The SIP
    denials were finalized in June and August of 2016. The States
    filed their petitions for review in this case in November and
    December of 2016, far outside of the sixty-day jurisdictional
    window for challenging SIP denials.             See 
    42 U.S.C. § 7607
    (b)(1); Dalton Trucking, Inc. v. EPA, 
    808 F.3d 875
    ,
    879–80 (D.C. Cir. 2015) (sixty-day window is jurisdictional).
    To the extent the States challenge these SIP denials, their
    untimely arguments lie beyond our jurisdiction.
    The States insist “[i]t is the FIP that is defective, and the
    FIP that is attacked here.” States’ Reply Br. 14. Even if
    accurate, that would be entirely beside the point. In EME
    58
    Homer II, the States claimed that EPA, as a condition for
    promulgating Good Neighbor FIPs, had to give them a second
    bite at compliant SIPs once the agency had calculated their
    significant contributions to downwind nonattainment. 572
    U.S. at 506–07. The Supreme Court explained that this was
    not a collateral attack because “[t]he gravamen of the . . .
    challenge” was that EPA failed to timely comply with a
    condition precedent for promulgating FIPs, “not that
    [its] disapproval of any particular SIP was erroneous.” Id. at
    507. As evidence, the Court emphasized that the States’
    argument “does not depend on the validity of the prior SIP
    disapprovals. Even assuming the legitimacy of those
    disapprovals, the question remains whether EPA was required
    to do more . . . to trigger the Agency’s statutory authority to
    issue a FIP.” Id. (emphasis added).
    By contrast, here, even if the States’ argument were to lead
    to the invalidation of the Update Rule, its success would
    “depend on the [in]validity of the prior SIP disapprovals,” and
    their argument expressly “assum[es]” the illegitimacy of
    EPA’s decisions. Id. at 507. That is the hallmark of an
    improper collateral attack. The true gravamen of the claim lies
    in the agency’s failure to timely act upon the States’ SIP
    submissions and, relatedly, its reliance on data compiled after
    the SIP action deadline. Both go directly to the legitimacy of
    the SIP denials. And, critically, those problems exist whether
    or not EPA follows up with a FIP of its own.
    Lastly, we cannot decide Wyoming’s claim that EPA
    “misled western States into believing that [it] would not apply
    the [the relevant] modeling to the West,” State Pet’rs’ Br. 42,
    and yet “applied the CSAPR modeling directly to the West
    without performing a regional or state-specific analysis and
    disapproved parts of [Wyoming’s] SIP revision,” id. at 43.
    59
    Wyoming lacks standing to press that argument here
    because its injury is traceable not to the Update Rule, but rather
    to separate rulemakings in which EPA “solicit[ed] public
    comment” on the appropriateness of applying the CSAPR
    modeling to Wyoming, 
    81 Fed. Reg. 81,712
    , 81,716 (Nov. 18,
    2016), and disapproved Wyoming’s SIP, 
    82 Fed. Reg. 9,142
    (Feb. 3, 2017). Because the Update Rule has not caused the
    complained-of injury, Wyoming cannot demonstrate a key
    element of standing, see Friends of the Earth, Inc. v. Laidlaw
    Environmental Servs. (TOC), Inc., 
    528 U.S. 167
    , 180–81
    (2000), and we are without authority to consider its argument.
    VI
    Finally, in light of our invalidation of the Update Rule in
    one respect, we take up the question of the proper remedy. As
    a general rule, we do not vacate regulations when doing so
    would risk significant harm to the public health or the
    environment. See Allied-Signal, Inc. v. Nuclear Regulatory
    Comm’n, 
    988 F.2d 146
    , 150–51 (D.C. Cir. 1993). For that
    reason, we have remanded without vacatur in previous Good
    Neighbor Provision cases. See EME Homer III, 795 F.3d at
    138; North Carolina v. EPA, 
    550 F.3d 1176
    , 1178 (D.C. Cir.
    2008) (per curiam). And we have done the same in other cases
    involving the Clean Air Act. See, e.g., Envtl. Def. Fund, Inc.
    v. EPA, 
    898 F.2d 183
    , 190 (D.C. Cir. 1990) (remanding without
    vacatur because vacatur would undermine “the enhanced
    protection of the environmental values covered by the [Clean
    Air Act]”).
    We follow the same course here. Vacatur of the Update
    Rule “could cause substantial disruption to the [allowance]
    trading markets that have developed.” EME Homer III, 795
    F.3d at 132. And “some good neighbor obligations [imposed
    by the Rule] may be appropriate for some of the relevant
    60
    upwind States.”    Id.    Thus, we conclude that vacatur is
    inappropriate.
    We decline Environmental Petitioners’ request, however,
    to impose a six-month timeframe on EPA’s promulgation of a
    revised rule. But of course, “we do not intend to grant an
    indefinite stay of the effectiveness of this court’s decision.”
    North Carolina, 550 F.3d at 1178. And Environmental
    Petitioners could attempt to “bring a mandamus petition to this
    court in the event that EPA fails to modify [the Rule] in a
    manner consistent with our . . . opinion.” Id.
    *    *   *    *   *
    For the foregoing reasons, the petitions for review are
    granted in part and denied in part.
    So ordered.
    

Document Info

Docket Number: 16-1406

Filed Date: 9/13/2019

Precedential Status: Precedential

Modified Date: 9/13/2019

Authorities (30)

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Sierra Club v. Environmental Protection Agency , 294 F.3d 155 ( 2002 )

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state-of-michigan-michigan-department-of-environmental-quality-and-state , 213 F.3d 663 ( 2000 )

association-of-american-railroads-v-interstate-commerce-commission-and , 978 F.2d 737 ( 1992 )

Stephen Thompson v. William P. Clark, Secretary of the ... , 741 F.2d 401 ( 1984 )

Appalachian Power Company v. Environmental Protection ... , 135 F.3d 791 ( 1998 )

environmental-defense-fund-inc-sierra-club-natural-resources-defense , 82 F.3d 451 ( 1996 )

city-of-las-vegas-v-manuel-lujan-jr-in-his-official-capacity-as , 891 F.2d 927 ( 1989 )

North Carolina v. Environmental Protection Agency , 531 F.3d 896 ( 2008 )

Natural Resources Defense Council v. Environmental ... , 571 F.3d 1245 ( 2009 )

Nuclear Energy Institute, Inc. v. Environmental Protection ... , 373 F.3d 1251 ( 2004 )

Commonwealth of Massachusetts v. United States Department ... , 93 F.3d 890 ( 1996 )

Ethyl Corporation v. Environmental Protection Agency, ... , 51 F.3d 1053 ( 1995 )

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