EME Homer City Generation, L.P. v. Environmental Protection Agency ( 2015 )


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  •  United States Court of Appeals
    FOR THE DISTRICT OF COLUMBIA CIRCUIT
    Argued February 25, 2015               Decided July 28, 2015
    No. 11-1302
    EME HOMER CITY GENERATION, L.P.,
    PETITIONER
    v.
    ENVIRONMENTAL PROTECTION AGENCY,
    RESPONDENT
    SAN MIGUEL ELECTRIC COOPERATIVE, ET AL.,
    INTERVENORS
    Consolidated with 11-1315, 11-1323, 11-1329, 11-1338,
    11-1340, 11-1350, 11-1357, 11-1358, 11-1359, 11-1360,
    11-1361, 11-1362, 11-1364, 11-1365, 11-1366, 11-1367,
    11-1368, 11-1369, 11-1371, 11-1372, 11-1373, 11-1374,
    11-1375, 11-1376, 11-1377, 11-1378, 11-1379, 11-1380,
    11-1381, 11-1382, 11-1383, 11-1384, 11-1385, 11-1386,
    11-1388, 11-1389, 11-1390, 11-1391, 11-1392, 11-1393,
    11-1394, 11-1395
    On Petitions for Review of a Final Rule Promulgated by
    the United States Environmental Protection Agency
    Bill Davis, Assistant Solicitor General, Office of the
    Attorney General for the State of Texas, argued the cause for
    2
    State and Local Petitioners. With him on the briefs on
    remand were Ken Paxton, Attorney General, Jon Niermann,
    Chief, Environmental Protection Division, Mark Walters,
    Assistant Attorney General, Derek Schmidt, Attorney
    General, Office of the Attorney General for the State of
    Kansas, Jeffrey A. Chanay, Chief Deputy Attorney General,
    Pamela Jo Bondi, Attorney General, Office of the Attorney
    General for the State of Florida, Jonathan A. Glogau, Chief,
    Complex Litigation, Henry V. Nickel, George P. Sibley III,
    Luther Strange, Attorney General, Office of the Attorney
    General for the State of Alabama, Robert D. Tambling,
    Assistant Attorney General, Greg Zoeller, Attorney General,
    Office of the Attorney General for the State of Indiana,
    Thomas M. Fisher, Solicitor General, David R. Taggart,
    Samuel S. Olens, Attorney General, Office of the Attorney of
    the State of Georgia, John E. Hennelly and James D. Coots,
    Senior Assistant Attorneys General, James D. ABuddy@
    Caldwell, Attorney General, Office of the Attorney General
    for the State of Louisiana, Megan K. Terrell, Assistant
    Attorney General, Herman Robinson, Jackie M. Marve,
    Elliott Vega, Donald Trahan, Deidra Johnson, Kathy M.
    Wright, Aaron D. Lindstrom, Solicitor General, Office of the
    Attorney General for the State of Michigan, Neil David
    Gordon, Assistant Attorney General, Sean Peter Manning,
    Chief, Environmental, Natural Resources, and Agriculture
    Division, Blake Johnson, Assistant Attorney General, Doug
    Peterson, Attorney General, Office of the Attorney General
    for the State of Nebraska, Harold E. Pizzetta III, Assistant
    Attorney General, Office of the Attorney General for the State
    of Mississippi, E. Scott Pruitt, Attorney General, Office of the
    Attorney General for the State of Oklahoma, Patrick Wyrick,
    Solicitor General, P. Clayton Eubanks, Deputy Solicitor
    General, J.B. Van Hollen, Attorney General at the time the
    brief was filed, Office of the Attorney General for the State of
    Wisconsin, Thomas J. Dawson, Assistant Attorney General,
    3
    Michael DeWine, Attorney General, Office of the Attorney
    General for the State of Ohio, Dale T. Vitale, Gregg H.
    Bachmann and Elizabeth Ewing, Assistant Attorneys General,
    Alan Wilson, Attorney General, Office of the Attorney
    General for the State of South Carolina, James Emory Smith,
    Jr., Deputy Solicitor General, and Leslie Sue Ritts. William J.
    Cobb for the State of South Carolina entered an appearance.
    Peter D. Keisler argued the cause for Industry and Labor
    Petitioners. With him on the briefs on remand were C.
    Frederick Beckner III, Roger R. Martella, Jr., Eric D.
    McArthur, Benjamin Beaton, F. William Brownell, P. Stephen
    Gidiere III, Grant Crandall, Arthur Traynor III, Eugene M.
    Trisko, Ann M. Seha, Daniel J. Kelly, William M. Bumpers,
    Joshua B. Frank, Megan H. Berge, Kelly M. McQueen, Janet
    J. Henry, Robert A. Manning, Joseph A. Brown, Mohammad
    O. Jazil, Bart E. Cassidy, Katherine L. Vaccaro, Todd E.
    Palmer, Jordan J. Hemaidan, Valerie L. Green, Jeffrey L.
    Landsman, Vincent M. Mele, Richard G. Stoll, Brian H. Potts,
    Steven G. McKinney, C. Grady Moore III, Ben H. Stone,
    Terese T. Wyly, Karl R. Moor, William L. Wehrum, Jr.,
    Margaret Claiborne Campbell, Bryon W. Kirkpatrick,
    Hahnah Williams Gaines, James S. Alves, Gary V. Perko,
    David M. Flannery, Kathy G. Beckett, Laura M. Goldfarb,
    Peter S. Glaser, Andrea Bear Field, Norman W. Fichthorn, E.
    Carter Chandler Clements, David R. Tripp, Dennis Lane,
    William F. Lane, and Maureen Harbourt.
    Shannon L. Goessling and Michael J. Nasi were on the
    brief for intervenor San Miguel Electric Cooperative, Inc. and
    Amicus Southeastern Legal Foundation, Inc. in support of
    petitioners on remand.      Robert M. Cohan entered an
    appearance.
    4
    Norman L. Rave, Jr. and Jessica O=Donnell, Attorneys,
    U.S. Department of Justice, argued the causes for
    respondents. With them on the brief were John C. Cruden,
    Assistant Attorney General, and Stephanie Hogan, Attorney,
    U.S. Environmental Protection Agency.
    Andrew G. Frank, Assistant Attorney General, Office of
    the Attorney General for the State of New York, argued the
    cause for State and Local Intervenors in support of
    respondent. With him on the brief on remand were Eric T.
    Schneiderman, Attorney General, Barbara D. Underwood,
    Solicitor General, Steven C. Wu, Deputy Solicitor General,
    Michael J. Myers, Assistant Attorney General, Brian E.
    Frosh, Attorney General, Office of the Attorney General for
    the State of Maryland, Mary E. Raivel, Assistant Attorney
    General, Roy Cooper, Attorney General, Office of the
    Attorney General for the State of North Carolina, Marc
    Bernstein, Special Deputy Attorney General, Peter F.
    Kilmartin, Attorney General, Office of the Attorney General
    for the State of Rhode Island, Gregory S. Schultz, Assistant
    Attorney General, George Jepsen, Attorney General, Office
    of the Attorney General for the State of Connecticut,
    Kimberly P. Massicotte and Scott N. Koschwitz, Assistant
    Attorneys General, Matthew Denn, Attorney General, Office
    of the Attorney General for the State of Delaware, Valerie M.
    Edge, Deputy Attorney General, Lisa Madigan, Attorney
    General, Office of the Attorney General for the State of
    Illinois, Matthew J. Dunn and Gerald T. Karr, Assistant
    Attorneys General, William J. Moore III, Benna Ruth
    Solomon, Carrie Noteboom, William H. Sorrell, Attorney
    General, Office of the Attorney General for the State of
    Vermont, Thea Schwartz, Assistant Attorney General, Maura
    Healey, Attorney General, Office of the Attorney General for
    the Commonwealth of Massachusetts, Frederick D.
    Augenstern, Assistant Attorney General, Karl Racine,
    5
    Attorney General, Office of the Attorney General for the
    District of Columbia, Todd Kim, Solicitor General, Scott J.
    Schwarz, and William R. Phelan, Jr.
    Graham G. McCahan argued the cause for Public Health
    Respondent Intervenors. With him on the brief on remand
    were Howard I. Fox, David S. Baron, Josh Stebbins, Vickie L.
    Patton, Sean H. Donahue, David Marshall, John Walke, and
    Emily Davis. Ann B. Weeks entered an appearance.
    Brendan K. Collins argued the cause for Industry
    Respondent Intervenors. With him on the brief on remand
    were Robert B. McKinstry, Jr., Lorene L. Boudreau, and
    James W. Rubin.
    Before: ROGERS, GRIFFITH, and KAVANAUGH, Circuit
    Judges.
    Opinion for      the   Court   filed   by   Circuit   Judge
    KAVANAUGH.
    KAVANAUGH, Circuit Judge: The Clean Air Act requires
    EPA to set national ambient air quality standards, or NAAQS.
    Those standards limit the levels of common pollutants in the
    ambient air. See 42 U.S.C. § 7409(a). Under the Act,
    individual States are responsible for ensuring attainment
    within their States of federal air quality standards. But air
    pollution is “heedless of state boundaries.” EPA v. EME
    Homer City Generation, L.P., 
    134 S. Ct. 1584
    , 1593, slip op.
    at 2 (2014). Emissions in upwind States therefore may affect
    air quality in downwind States. The Clean Air Act’s “good
    neighbor” provision speaks to that problem by proscribing
    upwind States from “emitting any air pollutant in amounts”
    that will “contribute significantly to nonattainment” of a
    NAAQS in a downwind State. 42 U.S.C. § 7410(a)(2)(D)(i).
    6
    This case concerns EPA’s effort to regulate interstate air
    pollution pursuant to the good neighbor provision.
    In 2011, EPA promulgated its latest good neighbor
    regulation, the Transport Rule, also known as the Cross-State
    Air Pollution Rule. A number of States, localities, and
    industry groups promptly challenged the Rule. They argued,
    among other things, that the Rule’s methodology for
    computing the upwind States’ emissions reduction obligations
    under the good neighbor provision exceeded EPA’s statutory
    authority. As relevant here, they contended that the Rule
    imposed uniform pollution reductions on upwind States
    regardless of the actual amounts of pollution that individual
    upwind States contributed to downwind States. According to
    petitioners, this methodology led to over-control of upwind
    States’ emissions.     Applying our precedents in North
    Carolina v. EPA, 
    531 F.3d 896
     (D.C. Cir. 2008), and
    Michigan v. EPA, 
    213 F.3d 663
     (D.C. Cir. 2000), this Court
    issued a 2-1 decision, with Judge Rogers dissenting, that
    agreed with petitioners and vacated the Rule. See EME
    Homer City Generation, L.P. v. EPA, 
    696 F.3d 7
    , 38 (D.C.
    Cir. 2012).
    On review, the Supreme Court reversed in a 6-2 decision.
    The Court ruled that the over-control problem did not require
    invalidation of the Rule “on its face.” EME Homer, 134 S.
    Ct. at 1609, slip op. at 31. In doing so, however, the Court
    stated that it “agree[d] with the Court of Appeals to this
    extent”:     The Transport Rule requires “unnecessary”
    emissions reductions when EPA “requires an upwind State to
    reduce emissions by more than the amount necessary to
    achieve attainment in every downwind State to which it is
    linked.” Id. at 1608-09, slip op. at 29-31. The Court stated
    that over-control of individual upwind States could be
    7
    contested through “particularized, as-applied challenge[s].”
    Id. at 1609, slip op. at 31.
    Now on remand, we consider several as-applied over-
    control challenges to EPA’s 2014 emissions budgets.
    Petitioners challenge the 2014 SO2 emissions budgets for
    Texas, Alabama, Georgia, and South Carolina. Petitioners
    also challenge the 2014 ozone-season NOX emissions budgets
    for Florida, Maryland, New Jersey, New York, North
    Carolina, Ohio, Pennsylvania, South Carolina, Texas,
    Virginia, and West Virginia. On this record, petitioners’ as-
    applied challenges are meritorious, and those 2014 emissions
    budgets are invalid. We therefore grant the petitions to that
    limited extent, and we remand without vacatur to EPA for it
    to reconsider those 2014 emissions budgets.
    In this opinion, we also must address a number of
    petitioners’ broader challenges to the Transport Rule that we
    did not have occasion to address in the prior case. We reject
    all of those claims and deny the petitions with respect to those
    issues.
    I
    The Transport Rule has been described in exhaustive
    detail in earlier phases of this litigation. See EPA v. EME
    Homer City Generation, L.P., 
    134 S. Ct. 1584
    , 1593-95, slip
    op. at 2-6 (2014). We summarize the main points here.
    The Clean Air Act regulates air quality through a federal-
    state collaboration.    First, EPA establishes air quality
    standards known as NAAQS. See 42 U.S.C. § 7409(a).
    Then, EPA identifies areas within the States that have not
    attained those NAAQS. See id. § 7407(d). Those are called
    “nonattainment” areas. Id. Next, the baton is passed to the
    States, which have the first opportunity to enact plans that
    8
    provide for the “implementation, maintenance, and
    enforcement” of the NAAQS. Id. § 7410(a)(1). States
    typically must enact and submit their plans – called State
    Implementation Plans or SIPs – within three years of any new
    or revised NAAQS. Id. If a State declines to submit a SIP, or
    if EPA finds that the State’s SIP fails to satisfy the minimum
    criteria of the Clean Air Act, EPA must promulgate a Federal
    Implementation Plan, or FIP, in its stead.              See id.
    § 7410(c)(1).
    Pollution emitted in upwind States can travel to
    downwind States. As a result, some “downwind States to
    which the pollution travels are unable to achieve clean air
    because of the influx of out-of-state pollution.” EME Homer,
    134 S. Ct. at 1593, slip op. at 1.
    The Clean Air Act’s good neighbor provision addresses
    the issue of interstate air pollution. That provision, as
    currently phrased, requires State SIPs to:
    contain adequate provisions –
    (i) prohibiting, consistent with the provisions of this
    subchapter, any source or other type of emissions
    activity within the State from emitting any air
    pollutant in amounts which will –
    (I) contribute significantly to nonattainment in, or
    interfere with maintenance by, any other State
    with respect to any such national primary or
    secondary ambient air quality standard . . . .
    42 U.S.C. § 7410(a)(2)(D). 1
    1
    The Rule imposes good neighbor obligations based on
    emissions that “contribute significantly to nonattainment” of
    9
    The Transport Rule at issue here represents EPA’s latest
    effort to implement the requirements of the good neighbor
    provision. The Rule focuses on three NAAQS. (NAAQS
    regulate individual pollutants measured over a specified time
    period.) The NAAQS covered by the Transport Rule are the
    8-hour ozone NAAQS, the annual particulate matter (or
    PM2.5) NAAQS, and the 24-hour PM2.5 NAAQS. See
    Transport Rule, 76 Fed. Reg. 48,208, 48,209 (Aug. 8, 2011).
    The Transport Rule does not directly regulate ozone and
    PM2.5.     As gases are “carried downwind, they are
    transformed, through various chemical processes, into
    altogether different pollutants.” EME Homer, 134 S. Ct. at
    1594, slip op. at 3. The pollutants that become ozone in
    downwind States start out in upwind States as emissions of
    nitrogen oxide (NOX). See Transport Rule, 76 Fed. Reg. at
    48,209-10. The pollutants that become PM2.5 in downwind
    States start out in upwind States as emissions of NOX and
    sulfur dioxide (SO2). Id. Therefore, the Transport Rule
    promotes downwind attainment of ozone and PM2.5 NAAQS
    by limiting NOX and SO2 emissions in upwind States.
    The Transport Rule employed a “two-step approach” to
    determine whether and to what extent a State must reduce its
    NOX and SO2 emissions pursuant to the good neighbor
    provision. EME Homer, 134 S. Ct. at 1596, slip op. at 7.
    In the first step, EPA identified the upwind States that
    “contribute significantly” to nonattainment of NAAQS in one
    NAAQS in downwind States and emissions that “interfere with
    maintenance” of NAAQS in downwind States. For ease of
    discussion, we focus on the “contribute significantly to
    nonattainment” prong. But our analysis of over-control applies to
    both prongs.
    10
    or more downwind States. See id. If a downwind State’s
    receptor site is not in attainment and if an upwind State
    caused more than 1% of the pollution at that site, then that
    upwind State was deemed to have “contributed significantly.”
    See id. (Receptor sites are locations in downwind States
    where EPA measures ambient air quality for pollutants
    regulated by the Clean Air Act. See id.)
    When an upwind State was found to contribute 1% or
    more of the relevant pollution at a downwind receptor, that
    upwind State was deemed to have a “linkage” to that
    downwind location. See Transport Rule, 76 Fed. Reg. at
    48,236. Any State with no such linkages was “screened out
    and exempted from regulation under the rule.” EME Homer,
    134 S. Ct. at 1596, slip op. at 7. Any State that had at least
    one linkage was subject to the Transport Rule. See id. EPA
    found 27 upwind States to have one or more linkages in
    downwind States. See id. Those 27 States were then subject
    to the second step of the Transport Rule.
    In the second step, EPA calculated the pollution
    reductions necessary for those 27 upwind States to comply
    with their good neighbor obligations. Recall that the good
    neighbor provision of the Act prohibits upwind States from
    emitting “amounts” of pollution that “contribute
    significantly” to nonattainment in downwind States. 42
    U.S.C. § 7410(a)(2)(D). EPA’s task at this second step was
    to decide what “amounts” of pollution each upwind State
    needed to reduce.
    But given what it described as the complexity of trying to
    assess the relative amount that each upwind State contributes
    to nonattainment in each downwind State, EPA decided to
    impose uniform emissions reductions on the upwind States
    covered by the Rule. See EME Homer, 134 S. Ct. at 1607,
    slip op. at 26-27. In other words, once a State was deemed
    11
    subject to the Transport Rule, its obligation to reduce
    emissions would no longer depend on the actual amounts it
    emitted into individual downwind States.
    Using its uniform approach, EPA calculated how much
    pollution each upwind State could eliminate if all of its
    sources applied pollution control technologies available at
    particular cost thresholds. See id. at 1596, slip op. at 7-8.
    Those cost thresholds were expressed in terms of cost per ton
    of emissions reduced.
    In the end, EPA adopted four cost thresholds for the 27
    upwind States subject to the Transport Rule. For all States
    subject to the Rule for annual NOX, EPA set a $500/ton cost
    threshold. See Transport Rule, 76 Fed. Reg. at 48,250. For
    States subject to the Rule for ozone-season NOX, EPA also set
    a $500/ton cost threshold. See id. For States subject to the
    Rule for SO2, EPA divided the States into two groups. For
    Group 1 States, EPA set a $2,300/ton cost threshold. See id.
    at 48,259. 2 For Group 2 States, EPA set a $500/ton cost
    threshold. See id. 3
    In the prior round of litigation, petitioners disputed
    EPA’s method of calculating emissions budgets for upwind
    States, and this Court found three main problems with EPA’s
    approach. First, the Rule could lead to over-control of
    upwind States – that is, emissions reductions beyond those
    2
    Group 1 States are Illinois, Indiana, Iowa, Kentucky,
    Maryland, Michigan, Missouri, New Jersey, New York, North
    Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia,
    and Wisconsin. See Transport Rule, 76 Fed. Reg. at 48,257.
    3
    Group 2 States are Alabama, Georgia, Kansas, Minnesota,
    Nebraska, South Carolina, and Texas. See Transport Rule, 76 Fed.
    Reg. at 48,257.
    12
    necessary to achieve attainment in downwind States. Second,
    the Rule could require States to reduce even insignificant
    contributions to pollution in downwind States. Third, the
    Rule did not purport to try to assess each upwind State’s
    relative contribution to nonattainment in downwind States.
    We therefore concluded that EPA’s methodology violated the
    Clean Air Act, and vacated the Transport Rule.
    The Supreme Court largely agreed with this Court on the
    first two issues but not on the third. The Court concluded,
    moreover, that those first two issues did not support
    “wholesale invalidation” of the Transport Rule. EME Homer,
    134 S. Ct. at 1608, slip op. at 29.
    Most important for present purposes is the first issue,
    over-control. The Supreme Court “agree[d] with the Court of
    Appeals to this extent”: The Transport Rule violates the
    statute when it “requires an upwind State to reduce emissions
    by more than the amount necessary to achieve attainment in
    every downwind State to which it is linked.” Id.
    But the Supreme Court concluded that the potential
    “over-control” did not “justif[y] wholesale invalidation of the
    Transport Rule.” Id. at 1608, slip op. at 28-29. Rather, as
    relevant here, if “any upwind State concludes it has been
    forced to regulate emissions . . . beyond the point necessary to
    bring all downwind States into attainment, that State may
    bring a particularized, as-applied challenge to the Transport
    Rule.” Id. at 1609, slip op. at 31.
    That’s where we are now.
    II
    We start by addressing petitioners’ as-applied challenges
    to the Transport Rule.
    13
    A
    As the Supreme Court stated in EME Homer, the Clean
    Air Act authorizes EPA to “prohibit[] only upwind emissions
    that contribute significantly to downwind nonattainment.”
    EPA v. EME Homer City Generation, L.P., 
    134 S. Ct. 1584
    ,
    1604, slip op. at 21 (2014); see also id. at 1607, slip op. at 27
    (EPA may “require the elimination of only those ‘amounts’ of
    pollutants that contribute to the nonattainment of NAAQS in
    downwind States.”); id. at 1603-04, slip op. at 21 (“EPA’s
    task is to reduce upwind pollution, but only in ‘amounts’ that
    push a downwind State’s pollution concentrations above the
    relevant NAAQS.”). 4
    In EME Homer, the Supreme Court rejected a facial
    challenge to EPA’s uniform approach and recognized that
    EPA must have some leeway to balance the possibilities of
    over-control and under-control of interstate emissions. The
    Court stated, however, that an upwind State may bring an as-
    applied challenge to EPA’s Transport Rule emissions budgets
    when EPA’s uniform approach has gone too far in proscribing
    emissions by upwind States. Id. at 1608-09, slip op. at 29-31.
    In such an as-applied challenge, how do we determine
    whether EPA has gone too far?
    4
    The Supreme Court held that the same was true for upwind
    States that “interfere with maintenance” at downwind locations.
    See EME Homer, 134 S. Ct. at 1604 n.18, slip op. at 22 n.18 (“Just
    as EPA is constrained, under the first part of the Good Neighbor
    Provision, to eliminate only those amounts that ‘contribute . . . to
    nonattainment,’ EPA is limited, by the second part of the provision,
    to reduce only by ‘amounts’ that ‘interfere with maintenance,’ i.e.,
    by just enough to permit an already-attaining State to maintain
    satisfactory air quality.”).
    14
    The Supreme Court answered that question in EME
    Homer. As relevant here, it stated that EPA may not require
    “an upwind State to reduce emissions by more than the
    amount necessary to achieve attainment in every downwind
    State to which it is linked.” Id. at 1608, slip op. at 29. If EPA
    does so, “the Agency will have overstepped its authority,
    under the Good Neighbor Provision, to eliminate those
    amounts that contribute to nonattainment.” Id. (alterations
    and internal quotation marks omitted).
    When can we say that an upwind State has been required,
    in the Supreme Court’s words, “to reduce emissions by more
    than the amount necessary to achieve attainment in every
    downwind State to which it is linked”? The answer again is
    clear from the Supreme Court’s EME Homer opinion: when
    those downwind locations would achieve attainment even if
    less stringent emissions limits were imposed on the upwind
    States linked to those locations. Id. at 1609, slip op. at 30-31.
    For example, assume that a downwind location would
    meet its NAAQS if the upwind States to which it is linked
    implemented emissions reduction technologies available at a
    cost of $100/ton. Once those technologies are in place, the
    downwind location will be in attainment. If the upwind
    States also implemented emissions reduction technologies
    available at a cost of $200/ton, the emissions reductions that
    flow from those technologies would not help the downwind
    location reach attainment because it already reached
    attainment when technologies available at a cost of $100/ton
    were implemented.
    In evaluating petitioners’ as-applied challenges, we thus
    must determine whether a downwind location would still
    attain its NAAQS if linked upwind States were subject to less
    stringent emissions limits. If we answer in the affirmative,
    EPA has overstepped its authority. Importantly, that does not
    15
    mean that every such upwind State would then be entitled to
    less stringent emissions limits. Some of those upwind States
    may still be subject to the more stringent emissions limits so
    as not to cause other downwind locations to which those
    States are linked to fall into nonattainment. Otherwise,
    however, upwind States in those circumstances should prevail
    in their as-applied challenges. 5
    B
    1
    Invoking EME Homer’s explicit authorization of as-
    applied challenges, petitioners challenge the 2014 SO2
    emissions budgets for Texas, Alabama, Georgia, and South
    Carolina. Recall that SO2 emissions transform (along with
    annual NOX) into PM2.5 in downwind States.
    We begin with Texas. At step one of its process for
    computing emissions budgets under the Transport Rule, EPA
    found Texas to be linked to PM2.5 nonattainment at only one
    downwind location, Madison, Illinois (171191007). Air
    Quality Modeling Final Rule Technical Support Document
    (June 2011), J.A. 2716. At step two, EPA grouped Texas
    with six other States and found that collectively those States
    must reduce emissions at the $500/ton level in 2014.
    Transport Rule, 76 Fed. Reg. 48,208, 48,257 (Aug. 8, 2011).
    5
    What if the downwind location would still reach attainment if
    one upwind State’s emissions limits were relaxed, but only so long
    as the other upwind States’ emissions limits were kept the same?
    We are not certain how the Supreme Court in EME Homer meant to
    resolve that question, but that issue is not presented in this case.
    Here, as we will explain, we know from EPA’s own data that the
    relevant downwind locations could reach attainment even if all of
    the relevant upwind States’ emissions limits were relaxed in a
    uniform manner.
    16
    However, EPA’s Technical Support Document for the
    Transport Rule – a document that EPA prepared when it
    proposed the Transport Rule – reveals that Madison, Illinois,
    would attain its annual PM2.5 NAAQS even if all of the
    upwind States linked to it implemented emissions reductions
    available at the $100/ton cost threshold. See Technical
    Support Document, Analysis to Quantify Significant
    Contribution (July 2010), J.A. 2231.6
    Without any good neighbor reductions, Madison’s
    maximum pollution level for PM2.5 would be 16.85 μg/m3 in
    2012. J.A. 2231. The NAAQS for annual PM2.5 is 15 μg/m3.
    See Transport Rule, 76 Fed. Reg. at 48,218. Madison
    therefore needed to reduce its pollution by 1.85 μg/m3.
    According to EPA’s projections, if every State connected to
    Madison implemented pollution controls at a cost of
    $100/ton, Madison would reduce its PM2.5 by at least that
    amount in 2014. See J.A. 2231.
    Yet EPA required every State connected to Madison to
    implement pollution controls available at a cost of $500/ton
    or greater. 7 But EPA’s projections showed that if every State
    6
    At oral argument, EPA stated that it “changed the inputs into
    the models between proposal and final [Rule], so we don’t know if”
    the analysis in the Technical Support Document “still is true.” Tr.
    of Oral Arg. 58-59. But in the final Rule, EPA did not provide any
    updated analysis regarding cost thresholds below $500/ton.
    Therefore, for the purposes of these proceedings, we may and must
    rely on EPA’s initial analysis of those lower thresholds. On
    remand, EPA may of course update its analysis, but it must
    consider cost thresholds below $500/ton and it must justify its final
    calculation consistent with the directions set forth by the Supreme
    Court and this Court.
    7
    Some States connected to Madison are in Group 1 for SO2,
    which must implement pollution controls at $2,300/ton. See
    17
    connected to Madison implemented pollution controls
    available at $500/ton, Madison’s PM2.5 would go down by
    2.61 μg/m3. J.A. 2231. That is 0.76 μg/m3 more than
    Madison needed to reduce in order to comply with its
    NAAQS.
    Put another way, by requiring reductions of $500/ton or
    greater for the upwind States linked to Madison, EPA
    required those States to help Madison overachieve its
    NAAQS by at least 0.76 μg/m3.
    Texas is linked only to Madison, Illinois. Therefore, by
    requiring Texas to implement pollution controls available at
    $500/ton when controls in all contributing upwind States at
    $100/ton would bring Madison into attainment, EPA has
    required Texas “to reduce emissions by more than the amount
    necessary to achieve attainment in every downwind State to
    which it is linked,” in clear violation of the Supreme Court’s
    directive. EME Homer, 134 S. Ct. at 1608, slip op. at 29.
    EPA similarly required Alabama, Georgia, and South
    Carolina to implement unnecessary emissions controls in their
    2014 SO2 emissions budgets.
    Alabama is linked to four downwind locations: Fulton,
    Georgia (131210039), Hamilton, Ohio (390610014),
    Hamilton, Ohio (390610042), and Hamilton, Ohio
    (390618001). See J.A. 2715. Note that some counties
    contain multiple receptor locations where EPA measures air
    quality; each location is demarcated with a unique
    identification number. EPA’s projections show that Fulton,
    Georgia, will come into attainment even if all States linked to
    Transport Rule, 76 Fed. Reg. at 48,259. Texas is in Group 2 for
    SO2, which requires pollution controls at $500/ton. Id.
    18
    it implement no good neighbor reductions in 2014.
    Moreover, all three locations in Hamilton, Ohio, will come
    into attainment even if all upwind States linked to them
    implement cost controls at $100/ton. See J.A. 2231. EPA is
    requiring Alabama to implement cost controls at $500/ton,
    when cost controls at $100/ton would bring every downwind
    location to which it is linked into attainment.
    Georgia is connected to two downwind locations:
    Jefferson, Alabama (10730023) and Jefferson, Alabama
    (10732003). See J.A. 2715. EPA’s projections show that
    Jefferson, Alabama (10730023) will come into attainment if
    all States linked to it implement cost controls at $400/ton and
    Jefferson, Alabama (10732003) will come into attainment if
    all upwind States linked to it implement cost controls at
    $200/ton. See J.A. 2231. EPA is requiring Georgia to
    implement cost controls at $500/ton, when cost controls at
    $400/ton would bring every downwind location to which it is
    linked into attainment.
    South Carolina is linked to one location, Fulton, Georgia
    (131210039). See J.A. 2716. EPA’s projections showed that
    that location would come into attainment if all upwind States
    linked to it implemented no cost controls. J.A. 2231. Yet
    EPA is requiring South Carolina to implement pollution
    controls at $500/ton.
    In short, EPA’s 2014 SO2 emissions budgets for Texas,
    Alabama, Georgia, and South Carolina require each of those
    States “to reduce emissions by more than the amount
    necessary to achieve attainment in every downwind State to
    which it is linked.” EME Homer, 134 S. Ct. at 1608, slip op.
    at 29. The reductions on those four States are “unnecessary to
    downwind attainment anywhere.” Id. at 1609, slip op. at 30.
    Those emissions budgets are therefore invalid.
    19
    2
    Next, we consider as-applied challenges to the Transport
    Rule’s 2014 ozone-season NOX emissions budgets related to
    the 1997 8-hour ozone NAAQS. Petitioners bring as-applied
    challenges to those 2014 budgets for Florida, Maryland, New
    Jersey, New York, North Carolina, Ohio, Pennsylvania, South
    Carolina, Texas, Virginia, and West Virginia.
    For ozone-season NOX, the only record data showed that
    the downwind locations to which 10 of those 11 upwind
    States (all but Texas) were linked would comply with their
    NAAQS in 2014 even with no good neighbor obligation on
    the upwind States. See Transport Rule, 76 Fed. Reg. at
    48,246 (linkages); J.A. 2550-76 (2014 Base Case Maximum
    Values). The conclusion is therefore simple. The 2014
    ozone-season NOX emissions budgets for those upwind States
    are invalid.
    For Texas, petitioners acknowledge that some good
    neighbor obligation for ozone-season NOX may be
    appropriate, but they say that it must be far lower than
    $500/ton. The record supports their argument. The evidence
    indicates that the two downwind locations to which Texas is
    linked for ozone – East Baton Rouge, Louisiana and Allegan,
    Michigan – could comply with their NAAQS even if the
    upwind States to which those two locations were linked were
    subject to cost thresholds far lower than $500/ton. The 2014
    ozone-season NOX emissions budget for Texas is therefore
    invalid.
    C
    Despite those rather clear transgressions of the statutory
    boundaries as set forth by the Supreme Court in EME Homer,
    EPA argues that petitioners’ over-control challenges should
    20
    fail. EPA advances two main arguments, neither of which is
    persuasive in light of the Supreme Court’s opinion.
    First, EPA contends that over-attainment in downwind
    locations does not mean that there is impermissible over-
    control of upwind States. Regarding Texas, for instance, EPA
    says that Madison’s over-attainment “reflects incidental
    benefits flowing from emission reductions by other upwind
    States that are necessary to” achieve attainment at other
    downwind locations. EPA Br. at 53-54.
    EPA’s argument directly contravenes the Supreme
    Court’s analysis in EME Homer. According to the Supreme
    Court, over-attainment in downwind locations is permissible
    when it is “incidental to reductions necessary to ensure
    attainment elsewhere.” EME Homer, 134 S. Ct. at 1608, slip
    op. at 29. That happens, for instance, when “the emissions
    reduction required to bring one linked downwind State into
    attainment” is “large enough to push other linked downwind
    States over the attainment line.” Id.
    The Supreme Court made crystal clear in EME Homer
    that over-attainment in downwind locations is impermissible
    when that excess attainment is “unnecessary.” Id. at 1609,
    slip op. at 29-30. “If EPA requires an upwind State to reduce
    emissions by more than the amount necessary to achieve
    attainment in every downwind State to which it is linked, the
    Agency will have overstepped its authority.” Id. at 1608, slip
    op. at 29. That is precisely what we have here.
    Two examples of upwind States’ linkages to Madison,
    Illinois, illustrate the difference between permissible and
    impermissible over-attainment at downwind locations.
    The upwind State of Indiana is linked to Madison, Illinois,
    as well as to 11 other downwind locations for annual PM2.5.
    21
    See J.A. 2715. To reach attainment, one of those downwind
    locations in Allegheny, Pennsylvania, needs all upwind States
    to which it is linked to implement cost controls at $2,300/ton
    or higher. See J.A. 2715-16; Transport Rule, 76 Fed. Reg. at
    48,257. Therefore, regardless of the cost threshold that is
    necessary to bring Madison into attainment, Indiana must
    implement controls available at $2,300/ton in order to satisfy
    its good neighbor obligation to Allegheny. As a result, the
    benefits that Madison, Illinois, receives from those higher
    controls on Indiana are merely incidental to the reductions on
    Indiana that are necessary to bring other locations into
    attainment.
    The upwind State of Texas, by contrast, is linked only to
    Madison, Illinois for annual PM2.5. Madison will come into
    attainment for annual PM2.5 if all States linked to it implement
    cost controls at $100/ton. If EPA requires Texas to
    implement cost controls at $500/ton, the over-attainment that
    Madison would achieve because of Texas’s incremental cost
    controls would not be an “incidental” benefit of other
    necessary good neighbor reductions imposed on Texas.
    Texas does not contribute significantly to nonattainment for
    PM2.5 at any other downwind location. Therefore, those
    $500/ton reductions from Texas cannot be necessary to – or
    even aid in – the achievement of attainment at any other
    downwind location. Requiring Texas to implement higher
    cost controls does not produce benefits that are “incidental” to
    attainment elsewhere; it produces benefits that are
    “unnecessary to downwind attainment anywhere.” EME
    Homer, 134 S. Ct. at 1609, slip op. at 29-30.
    Second, EPA argues that “imposing less stringent
    emission budgets” on those upwind States “would be
    inequitable and contrary to the rationale underlying uniform
    cost thresholds.” EPA Br. at 55. Specifically, EPA says that
    22
    uniform cost thresholds are important because they subject
    “to stricter regulation those States that have done relatively
    less in the past to control their pollution” and prevent those
    States from “free riding on their neighbors’ efforts to reduce
    pollution.” Id. (quoting EME Homer, 134 S. Ct. at 1607, slip
    op. at 27).
    But EPA’s argument again flatly contradicts the
    crystalline holding of the Supreme Court in EME Homer.
    The Supreme Court could not have said it more clearly: “If
    EPA requires an upwind State to reduce emissions by more
    than the amount necessary to achieve attainment in every
    downwind State to which it is linked, the Agency will have
    overstepped its authority.” EME Homer, 134 S. Ct. at 1608,
    slip op. at 29. The Court therefore explicitly authorized as-
    applied challenges that, when successful under the principles
    outlined by the Court, will necessarily mean a lack of
    uniformity in certain circumstances.
    It bears mention, moreover, that the Supreme Court’s
    conclusion on this point tracked the affirmative representation
    made by the Deputy Solicitor General to the Supreme Court
    that as-applied over-control challenges by upwind States
    would be permissible – even though such challenges, when
    successful, would necessarily mean the cost thresholds would
    not be uniform. 8 EPA is now saying something to this Court
    8
    The Supreme Court’s language allowing such as-applied
    over-control challenges was no accident, as examination of the oral
    argument transcript in that case reveals:
    Justice Sotomayor: . . . [B]elow, the government conceded that
    there was a theoretical possibility that some States could be
    overcontrolled, that they would be implementing measures that
    would reduce their contributions to pollution below the 1
    23
    that is tension with, if not in contravention of, what the
    Deputy Solicitor General told the Supreme Court.
    In sum, EPA’s uniform cost thresholds have required
    States to reduce pollutants beyond the point necessary to
    percent. Assume that – I think there’s a theoretical possibility
    of that – but that your approach was basically fine.
    What would we do about that? First of all, are there measures
    States can take to get out of the FIP if it’s inappropriate to
    them because of overcontrol? And if not – and how do they do
    it? I mean, what’s the process? If we think there’s a flaw, do
    we vacate the rule? . . . .
    Mr. Stewart [Deputy Solicitor General]: . . . [E]ven if we win
    everything that’s at issue in this Court, the case is not over.
    There are a variety of more specific challenges to the details of
    the rule that the D.C. Circuit found it unnecessary to address.
    And so if we won on the issues that are before the Court, the
    case would be remanded and there would be an opportunity for
    the court below to consider those. And to the extent –
    Chief Justice Roberts: Including – including the overcontrol
    argument, or would that have been done?
    Mr. Stewart: Well, to – to the extent that any State had – and I
    don’t know the – the pending as-applied challenges at this
    level of detail. But to the extent that any State has a properly
    preserved challenge to the effect that it is actually likely to be
    subject to overcontrol, then that could be heard by the court of
    appeals. The court of appeals could determine both whether
    that is, in fact, likely to happen and whether, if it does happen,
    that would render the rule arbitrary and capricious as to that
    State.
    Transcript of Oral Argument at 26:24-28:18, EPA v. EME Homer
    City Generation, L.P., 
    134 S. Ct. 1584
     (2014) (Nos. 12–1182, 12–
    1183) (italics added).
    24
    achieve downwind attainment. That violates the Supreme
    Court’s clear mandate in EME Homer.
    D
    The next question is the remedy for the invalid 2014
    emissions budgets. We will remand without vacatur the 2014
    emissions budgets that we have found invalid. Although
    there have been some critiques of the practice of remanding
    without vacatur, this Court’s precedents authorize remand
    without vacatur in certain limited circumstances. See, e.g.,
    North Carolina v. EPA, 
    550 F.3d 1176
    , 1178 (D.C. Cir.
    2008); Advocates for Highway and Auto Safety v. Federal
    Motor Carrier Safety Administration, 
    429 F.3d 1136
    , 1151
    (D.C. Cir. 2005). Here, as petitioners themselves note,
    vacatur could cause substantial disruption to the trading
    markets that have developed around the 2014 emissions
    budgets. Cf. NACS v. Board of Governors of Federal Reserve
    System, 
    746 F.3d 474
    , 493 (D.C. Cir. 2014) (remanding
    without vacating where “disruptive effect of vacatur [wa]s
    high”) (internal quotation marks omitted). Moreover, as
    petitioners have acknowledged, some good neighbor
    obligations may be appropriate for some of the relevant
    upwind States. In these circumstances, remand without
    vacatur is appropriate.
    On remand, EPA, petitioners, or other parties as
    appropriate may provide new evidence, data, or calculations.
    To be sure, remand without vacatur creates a risk that an
    agency may drag its feet and keep in place an unlawful
    agency rule. With that in mind, we expect and urge EPA to
    move promptly on remand. If not, petitioners may promptly
    bring suit against the Administrator for “failure . . . to
    perform,” in addition to other appropriate remedies petitioners
    may choose to pursue. 42 U.S.C. § 7604(a)(2).
    25
    III
    We now address petitioners’ other challenges to the
    Transport Rule that we did not have occasion to reach during
    petitioners’ last trip to this Court.
    A
    To begin with, the State and local petitioners contend that
    EPA lacked authority to promulgate the Transport Rule FIPs
    for 22 of the 27 covered States. Starting in 2007, EPA
    approved SIPs for those 22 States. See Transport Rule, 76
    Fed. Reg. 48,208, 48,220-21 (Aug. 8, 2011). 9 Those SIPs
    sought to fulfill the States’ good neighbor obligations by
    complying with the regulatory framework laid out in the 2005
    Clean Air Interstate Rule or CAIR.
    But in North Carolina v. EPA in 2008, this Court found
    CAIR to be “fundamentally flawed,” and instructed EPA to
    build a replacement for CAIR “from the ground up.” North
    Carolina v. EPA, 
    531 F.3d 896
    , 929 (D.C. Cir. 2008). The
    Court did not vacate CAIR. See North Carolina v. EPA, 
    550 F.3d 1176
    , 1178 (D.C. Cir. 2008). Our decision in North
    Carolina prompted EPA to develop the Transport Rule.
    EPA may promulgate a FIP only if a State declines to
    submit a SIP or if EPA finds that the State’s SIP does not
    meet all of the applicable requirements of the Clean Air Act.
    See 42 U.S.C. § 7410(c)(1). 10 EPA, in other words, may not
    9
    Those States are: Alabama, Arkansas, Connecticut, Florida,
    Georgia, Illinois, Indiana, Iowa, Kentucky, Louisiana, Maryland,
    Massachusetts, Minnesota, Mississippi, Missouri, New York, North
    Carolina, Ohio, Pennsylvania, South Carolina, Virginia, and West
    Virginia. See Transport Rule, 76 Fed. Reg. at 48,220-21.
    10
    The full provision provides that:
    26
    promulgate a FIP for a State if it has previously approved a
    SIP for that State. Here, EPA had approved SIPs for 22 of the
    27 States covered by the Transport Rule. Therefore, in order
    to promulgate the Transport Rule FIPs, EPA first needed to
    revise its approval for the CAIR SIPs.
    The Clean Air Act allows EPA to “revise” a prior SIP
    approval if that approval “was in error.” Id. § 7410(k)(6). In
    particular, the Clean Air Act provides that whenever “the
    Administrator determines that the Administrator’s action
    approving, disapproving, or promulgating any plan or plan
    revision (or part thereof) . . . was in error, the Administrator
    may . . . revise such action as appropriate without requiring
    any further submission from the State.” Id. Here, EPA
    invoked its correction powers under Subsection 7410(k)(6) to
    “rescind any statements that the [CAIR] SIP submissions
    either satisfy or relieve the state of the obligation to submit a
    SIP to satisfy the requirements of” the good neighbor
    provision. See Transport Rule, 76 Fed. Reg. at 48,220.
    The Administrator shall promulgate a Federal implementation
    plan at any time within 2 years after the Administrator – (A)
    finds that a State has failed to make a required submission or
    finds that the plan or plan revision submitted by the State does
    not satisfy the minimum criteria established under subsection
    (k)(1)(A) of this section, or (B) disapproves a State
    implementation plan submission in whole or in part, unless
    the State corrects the deficiency, and the Administrator
    approves the plan or plan revision, before the Administrator
    promulgates such Federal implementation plan.
    42 U.S.C. § 7410(c)(1).
    27
    Petitioners argue that EPA’s use of its Subsection
    7410(k)(6) correction power was invalid. They advance three
    distinct contentions.
    First, petitioners argue that EPA’s initial approval of the
    CAIR SIPs was not “in error,” and therefore could not be
    corrected pursuant to Subsection 7410(k)(6). But when our
    decision in North Carolina deemed CAIR to be an invalid
    effort to implement the requirements of the good neighbor
    provision, that ruling meant that the initial approval of the
    CAIR SIPs was in error at the time it was done. As the
    Supreme Court stated: “A judicial construction of a statute is
    an authoritative statement of what the statute meant before as
    well as after the decision of the case giving rise to that
    construction.” Rivers v. Roadway Express, Inc., 
    511 U.S. 298
    , 312-13 (1994).
    Second, petitioners argue that because we remanded
    CAIR without vacatur in North Carolina, we cannot now
    conclude that EPA’s SIP approvals under CAIR were “in
    error.” But petitioners misunderstand why we declined to
    vacate CAIR in North Carolina. We left CAIR in effect
    temporarily because doing so was necessary to “at least
    temporarily preserve the environmental values covered by
    CAIR” until it could be “replaced by a rule consistent with
    our opinion.” North Carolina, 550 F.3d at 1178.
    But critically, the decision to remand without vacatur did
    not alter the core holding of North Carolina: CAIR contained
    “fatal flaws” and needed to be replaced. North Carolina, 531
    F.3d at 901. Our decision to remand without vacating,
    therefore, does not change the conclusion that EPA’s original
    approvals of the CAIR SIPs were “in error” given our
    decision in North Carolina.
    28
    Third, petitioners say that EPA ran afoul of the Clean Air
    Act’s requirement that EPA correct SIP approval errors “in
    the same manner as the approval.” 42 U.S.C. § 7410(k)(6).
    We reject that argument because EPA did correct the SIP
    approvals “in the same manner” as it originally issued them.
    Both the original SIP approvals and the corrections were
    effectuated through rulemaking pursuant to the requirements
    of the Clean Air Act.
    It is true that, as petitioners note, EPA approved the
    original CAIR SIPs through rulemaking with notice and
    comment, but revised them through rulemaking without
    notice and comment. See Transport Rule, 76 Fed. Reg. at
    48,221. But both actions complied with the Clean Air Act’s
    framework for rulemaking.
    Under the Clean Air Act, rulemaking can be
    accomplished without notice and comment when EPA has
    “good cause” to forgo that extra procedure. See 42 U.S.C.
    § 7607(d)(1). Specifically, the Clean Air Act permits EPA to
    conduct rulemaking without notice and comment when doing
    so would be appropriate under Subsection 553(b) of the
    Administrative Procedure Act, which sets forth a “good
    cause” exception. 11
    11
    The Clean Air Act exempts from its notice and comment
    requirements “any rule or circumstance referred to in
    subparagraphs (A) or (B) of subsection 553(b) of title 5.” 42
    U.S.C. § 7607(d)(1); cf. General Motors Corp. v. Ruckelshaus, 
    742 F.2d 1561
    , 1565 n.6 (D.C. Cir. 1984). Those subparagraphs, in
    turn, provide two exceptions to the notice and comment
    requirement: (A) when the agency enacts interpretative rules, and
    (B) when the agency has good cause to forgo notice and comment.
    See 5 U.S.C. § 553(b)(A)-(B).
    29
    Subsection 553(b)(B) provides that an agency has “good
    cause” to conduct rulemaking without notice and comment
    when proceeding through notice and comment would be
    “impracticable, unnecessary, or contrary to the public
    interest.” 5 U.S.C. § 553(b)(B). This Court has previously
    affirmed the use of the “good cause” exception when
    rulemaking without notice and comment is “a reasonable and
    perhaps inevitable response to” a “court order.” American
    Federation of Government Employees, AFL-CIO v. Block,
    
    655 F.2d 1153
    , 1157 (D.C. Cir. 1981).
    EPA explained here that it invoked the “good cause”
    exception because this Court’s decision in North Carolina
    invalidated the CAIR SIPs and commentators could not have
    said anything during a notice and comment period that would
    have changed that fact. See Transport Rule, 76 Fed. Reg. at
    48,222 (“EPA must accept the Court’s conclusion that
    compliance with CAIR does not satisfy the requirements of
    [the good neighbor provision] and lacks discretion to reach a
    different conclusion.”). EPA is correct that it would have
    been utterly “unnecessary” and wasteful to go through notice
    and comment given our decision in North Carolina. See 5
    U.S.C. § 553(b)(B).
    In sum, EPA’s initial approval of the CAIR SIPs was “in
    error.” And EPA corrected that approval “in the same
    manner” as it approved the SIPs – that is, through a valid
    rulemaking. 12
    12
    Our conclusion on Subsection 7410(k)(6) is limited to the
    unusual circumstances here, in which a federal court says that EPA
    lacked statutory authority at the time to approve a SIP. We do not
    take a position on use of Subsection 7410(k)(6) in any other
    circumstances.
    30
    B
    Next, petitioners challenge two models used by EPA to
    create the Transport Rule. This Court’s review of EPA’s
    modeling choices is deferential. It is “only when the model
    bears no rational relationship to the characteristics of the data
    to which it is applied that we will hold that the use of the
    model was arbitrary and capricious.” Appalachian Power Co.
    v. EPA, 
    135 F.3d 791
    , 802 (D.C. Cir. 1998).
    First, petitioners argue that EPA’s model for creating air
    quality projections was arbitrary and capricious because it
    used insufficient real-world data.       In order to project
    downwind air quality, EPA used real-world data from 2003 to
    2007. See Transport Rule, 76 Fed. Reg. at 48,233-36.
    Petitioners argue that EPA should have verified its findings
    against air quality measured after 2007 as well.
    EPA’s decision not to use post-2007 air quality data in
    the model was reasonable. As already discussed, in 2008, this
    Court invalidated CAIR, but we left that Rule in place until
    the Agency came up with a replacement. See North Carolina,
    550 F.3d at 1178. As a result, air quality data after 2007
    reflected “large emission reductions from CAIR” that would
    ultimately be displaced by the Transport Rule. See Transport
    Rule, 76 Fed. Reg. at 48,230.
    Moreover, given our narrow holding here, EPA’s use of its
    correction power under Subsection 7410(k)(6) should not be read to
    diminish the scope or force of Subsection 7410(k)(5), which
    provides that whenever “the Administrator finds that the applicable
    implementation plan for any area is substantially inadequate . . . the
    Administrator shall require the State to revise the plan as necessary
    to correct such inadequacies.” 42 U.S.C. § 7410(k)(5).
    31
    As EPA reasonably explained, because “the Transport
    Rule will replace CAIR, we must model a future year base
    case which does not assume that CAIR is in place (a ‘no-
    CAIR’ case).” Id.
    Second, petitioners object to the model EPA used to set
    State emissions budgets. That model predicted the generation
    and emissions produced at electric generating units within the
    States covered by the Transport Rule. Petitioners say that
    those predictions were arbitrary because EPA knew that there
    were “discrepancies” between the predictions and the actual
    generation and emissions at those units. EPA contends that
    the model’s “discrepancies are small and random and thus do
    not result in biases.” Transport Rule Primary Response to
    Comments (June 2011), J.A. 2089.
    We will not invalidate EPA’s predictions solely because
    there might be discrepancies between those predictions and
    the real world. That possibility is inherent in the enterprise of
    prediction. The best model might predict that the Nationals
    will win the World Series in 2015. If that does not happen,
    you can’t necessarily fault the model. As we have said
    previously, the fact that a “model does not fit every
    application perfectly is no criticism; a model is meant to
    simplify reality in order to make it tractable.” Chemical
    Manufacturers Association v. EPA, 
    28 F.3d 1259
    , 1264 (D.C.
    Cir. 1994).
    C
    Next, petitioners argue that EPA failed to properly
    regulate pursuant to the “interfere with maintenance” prong of
    the good neighbor provision. The Transport Rule regulates
    two different kinds of interstate air pollution. As we have
    discussed, the Rule regulates upwind emissions that
    “contribute significantly to nonattainment” of NAAQS in
    32
    downwind States. 42 U.S.C. § 7410(a)(2)(D)(i). The Rule
    also regulates upwind emissions that “interfere with
    maintenance” of NAAQS in downwind States that have
    achieved attainment. Id.
    In North Carolina, we held that EPA must give
    “independent significance” to those prongs. North Carolina,
    531 F.3d at 910. We found that CAIR failed to do that.
    CAIR applied the interference with maintenance provision “in
    conjunction with the significant contribution to nonattainment
    provision and so did not use the maintenance prong to
    separately identify upwind States subject to CAIR.” Id.
    (quoting 71 Fed. Reg. 25,328, 25,337 (Apr. 28, 2006)). Put
    another way, areas that found “themselves barely meeting
    attainment . . . due in part to upwind sources interfering with
    that attainment ha[d] no recourse under EPA’s interpretation
    of the interference prong” in CAIR. Id.
    Petitioners argue that the Transport Rule repeats the same
    error. We disagree.
    The Transport Rule’s methodology affords independent
    effect to the “interfere with maintenance” prong of the good
    neighbor provision. In formulating the Transport Rule, EPA
    “evaluat[ed] contributions to identified maintenance receptors
    as well as contributions to identified nonattainment
    receptors.” Transport Rule, 76 Fed. Reg. at 48,227; see also
    id. at 48,212 (“EPA thus identified specific emission
    reduction responsibilities for each upwind state found to
    significantly contribute to nonattainment or interfere with
    maintenance in other states.”) (emphasis added).
    With the Transport Rule, EPA created a distinct category
    of maintenance receptors that could independently trigger an
    upwind State’s good neighbor obligations. See id. at 48,228.
    Therefore, the Transport Rule complied with North
    33
    Carolina’s requirement that EPA give the nonattainment and
    maintenance prongs “independent significance.”
    D
    Petitioners also raise several objections to EPA’s
    methodology for identifying upwind States that “interfere
    with maintenance” at downwind locations.
    First, petitioners argue that EPA’s methodology for
    identifying upwind emissions that “interfere with
    maintenance” failed to “identify and analyze only those
    upwind emissions that might actually threaten continued
    attainment.” State and Local Br. at 20. Second, they argue
    that the methodology improperly required emissions
    reductions in upwind States without accounting for
    maintenance secured by the downwind States’ own
    maintenance plans. 13     As a result, it risked requiring
    emissions reductions that would be duplicative or
    unnecessary. Third, they say that EPA erred by focusing
    “exclusively on the utility sector for emissions reductions,”
    when that sector may not produce the emissions that interfere
    with maintenance at downwind locations. Id. at 21.
    At bottom, each of those claims is an argument that
    EPA’s methodology could lead to over-control of upwind
    States that are found to interfere with maintenance at a
    downwind location. That could prove to be correct in certain
    13
    When a State believes that an area within its borders has
    reached a national air quality standard, that State may seek a
    “redesignation” of that area from “nonattainment” to attainment.
    See 42 U.S.C. § 7505a(a). That request must be accompanied by a
    revision to the State’s SIP, which “provide[s] for the maintenance
    of the” NAAQS “for at least 10 years after the redesignation.” Id.
    That revision is called a “maintenance plan.”
    34
    locations. But the Supreme Court made clear in EME Homer
    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.” EME Homer, 134 S. Ct. at 1609, slip op.
    at 31. And petitioners do not point to any actual such
    instances of over-control at downwind locations.
    As the Supreme Court stated, under the “interfere with
    maintenance” prong, EPA may only limit emissions “by just
    enough to permit an already-attaining State to maintain
    satisfactory air quality.” Id. at 1604 n.18, slip op. at 22 n.18.
    If States have been forced to reduce emissions beyond that
    point, affected parties will have meritorious as-applied
    challenges.
    E
    Finally, petitioners advance three new arguments on
    remand that we may not entertain at this time.
    We may hear objections to EPA rules or procedures only
    if the objections were “raised with reasonable specificity
    during the period for public comment.”               42 U.S.C.
    § 7607(d)(7)(B). If it was “impracticable to raise a particular
    objection” or if “the grounds for the objection arose after that
    period,” parties still must petition EPA for administrative
    reconsideration before raising the issue before this Court. See
    Utility Air Regulatory Group v. EPA, 
    744 F.3d 741
    , 746 (D.C.
    Cir. 2014).      This may sometimes seem a roundabout
    procedure, but that is what the statute requires and what we
    therefore must insist upon. If EPA fails to conduct a
    reconsideration hearing, the party may seek review of that
    decision in this Court. See 42 U.S.C. § 7607(d)(7)(B) (“If the
    Administrator refuses to convene such a proceeding, such
    35
    person may seek review of such refusal in the United States
    court of appeals for the appropriate circuit.”).
    First, petitioners argue that EPA violated the Clean Air
    Act’s notice and comment requirements by significantly
    amending the Rule between the proposed and final versions
    without providing additional opportunity for notice and
    comment. Because that argument is an objection to the notice
    and comment process itself, petitioners obviously did not and
    could not have raised it during the period for public comment.
    Under Subsection 7607(d)(7)(B), however, the only
    appropriate path for petitioners to raise this issue is through
    an initial petition for reconsideration to EPA. At least one
    party to the present suit has done just that. See Br. of
    Intervenor San Miguel Electric Cooperative, Inc. and Amicus
    Southeastern Legal Foundation, Inc. at 27. EPA has not ruled
    on that request, and the parties have not asked for judicial
    review of EPA’s delay in acting. Id. We are without
    authority at this time to reach this question.
    Second, petitioners argue that EPA did not have authority
    to promulgate certain Transport Rule FIPs because those FIPs
    were signed by the EPA Administrator before EPA published
    its disapproval of the CAIR SIPs in the Federal Register.
    Petitioners did not raise this issue before the Agency during
    notice and comment, and EPA has not denied any petition for
    reconsideration raising this objection. We therefore may not
    entertain it now.
    Third, petitioners argue that EPA exceeded its authority
    by finding linkages based on upwind contributions to
    downwind locations that were designated in “attainment” or
    “unclassifiable.” See 42 U.S.C. § 7407(d). Petitioners again
    did not raise this argument during the notice and comment
    period or otherwise comply with 42 U.S.C. § 7607(d)(7)(B).
    36
    This question is therefore not properly before this Court, and
    we may not reach it now.
    ***
    To sum up: We hold invalid the 2014 SO2 emissions
    budgets for Alabama, Georgia, South Carolina, and Texas, as
    well as the 2014 ozone-season NOX budgets for Florida,
    Maryland, New Jersey, New York, North Carolina, Ohio,
    Pennsylvania, South Carolina, Texas, Virginia, and West
    Virginia. We remand without vacatur to EPA for it to
    reconsider those emissions budgets. We reject all of
    petitioners’ other challenges to the Transport Rule, including
    all of their facial challenges to the Rule. The petitions for
    review are therefore granted in part and denied in part.
    So ordered.