Breiding v. Eversource Energy ( 2019 )


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  •           United States Court of Appeals
    For the First Circuit
    No. 18-1995
    SCOTT BREIDING; AMY POLLUTRO; MIKAELA ORTSTEIN-OTERO; BENJAMIN
    ROSE; MARGARET LEWIS; RICHARD LEWIS; ERIC LONG; PETER STEERS;
    BRADFORD KEITH; JOHN ODUM; DAVID LEIGHTON; DONNA CORDEIRO;
    JANICE ANGELILLO; ANNA MARIA FORNINO; MICHELE CASSETTA; JUDY
    CENNAMI, on behalf of themselves and others similarly situated,
    Plaintiffs, Appellants,
    ERIK ALLEN; NICHOLAS CORREIA; JANICE BRADY; OPAL ASH;
    ROBERTO PRATS; MARK LEJEUNE,
    Plaintiffs,
    v.
    EVERSOURCE ENERGY, a Massachusetts voluntary association;
    AVANGRID, INC., a New York corporation,
    Defendants, Appellees.
    APPEAL FROM THE UNITED STATES DISTRICT COURT
    FOR THE DISTRICT OF MASSACHUSETTS
    [Hon. Denise J. Casper, U.S. District Judge]
    Before
    Torruella, Selya, and Kayatta,
    Circuit Judges.
    Thomas M. Sobol, with whom Kristie A. LaSalle, Bradley
    Vettraino, Steve W. Berman, Hagens Berman Sobol Shapiro LLP, David
    F. Sorensen, Michael Dell'Angelo, Glen L. Abramson, and Berger
    Montague PC were on brief, for appellants.
    Whitney E. Street, Block & Leviton LLP, Sandeep Vaheesan, and
    Open Markets Institute on brief for Open Markets Institute as
    amicus curiae.
    Richard P. Bress and John D. Donovan, Jr., with whom Shannen
    W. Coffin, Douglas G. Green, Steptoe & Johnson LLP, Chong S. Park,
    Ropes & Gray LLP, Marguerite M. Sullivan, Allyson M. Maltas,
    Caroline A. Flynn, and Latham & Watkins LLP were on brief, for
    appellees.
    September 18, 2019
    KAYATTA, Circuit Judge.          Eversource Energy and Avangrid,
    Inc.    ("the    defendants")     are    two     large   energy    companies      that
    purchase natural gas directly from producers and then resell that
    gas to retail natural gas consumers throughout New England.                        In
    order to transport the natural gas that the defendants purchase
    from far-away producers to their own, localized system of pipeline
    infrastructure for delivery to their customers, the defendants
    reserve transportation capacity along the interstate Algonquin Gas
    pipeline.       The plaintiffs, a putative class of retail electricity
    customers in New England, allege that the defendants strategically
    reserved excess capacity along the Algonquin Gas pipeline without
    using    or     reselling   it.        This    conduct,     they   claim,    unduly
    constrained the volume of natural gas flowing through New England,
    thereby   raising      wholesale       natural    gas    prices,   which    in    turn
    resulted in higher retail electricity rates paid by New England
    electricity consumers.
    The plaintiffs brought this lawsuit in the U.S. District
    Court   for     the   District    of    Massachusetts,      asserting      that   the
    defendants' conduct violated section 2 of the Sherman Act, 
    15 U.S.C. § 2
    , and various state antitrust and consumer-protection
    laws. The district court dismissed the plaintiffs' claims as being
    barred by the filed-rate doctrine and, alternatively, for lack of
    antitrust standing and the plaintiffs' failure to plausibly allege
    a monopolization claim under the Sherman Act.                        Although our
    - 3 -
    reasoning differs from that of the district court in several
    respects,    we   agree   that    the    filed-rate    doctrine      presents   an
    insurmountable hurdle for the plaintiffs' federal and state-law
    claims.     We therefore find no need to reach the district court's
    alternative grounds for dismissal.
    I.
    Because the district court disposed of the plaintiffs'
    claims on a motion to dismiss for failure to state a claim, Fed.
    R. Civ. P. 12(b)(6), "we take as true all well-pleaded facts in
    [their] complaint[], scrutinize them in the light most hospitable
    to [their] theory of liability, and draw all reasonable inferences
    therefrom in [their] favor."             Fothergill v. United States, 
    566 F.3d 248
    , 251 (1st Cir. 2009).           In so doing, we may also consider
    "facts subject to judicial notice, implications from documents
    incorporated      into    the     complaint,     and   concessions       in     the
    complainant's response to the motion to dismiss."                 Arturet-Vélez
    v. R.J. Reynolds Tobacco Co., 
    429 F.3d 10
    , 13 n.2 (1st Cir. 2005).
    We first trace the regulatory contours of the relevant
    markets for natural gas and electricity before turning to the
    details   of   the   plaintiffs'        antitrust   and     unfair   competition
    claims.
    A.
    "Wellhead" sales comprise the first step in the chain of
    market    transactions     that    readies      extracted    natural    gas     for
    - 4 -
    consumption in the form of retail electricity.          At this initial
    stage, natural gas producers sell natural gas to direct purchasers
    through gas futures contracts, in which the producer agrees to
    sell a specific quantity of natural gas at some fixed time in the
    future   to    the   direct   purchaser.    Load-distribution   companies
    (LDCs) -- those entities that locally distribute natural gas,
    primarily to retail consumers who use the gas for heating and
    cooking -- have a relatively predictable need for natural gas and,
    thus, often make use of this type of contract.1          Consumers with
    more variable demand for natural gas, such as power generators,
    often purchase gas on the secondary wholesale "spot market."         The
    spot market for natural gas allows direct purchasers that find
    themselves with rights to excess, unneeded natural gas to resell
    those rights in the immediate or near future.
    The Federal Energy Regulatory Commission (FERC) is the
    agency charged with implementing and executing the Natural Gas Act
    (NGA), "a comprehensive scheme of federal regulation of 'all
    wholesales of natural gas in interstate commerce.'" N. Nat. Gas
    Co. v. State Corp. Comm'n, 
    372 U.S. 84
    , 91 (1963) (quoting Phillips
    Petroleum Co. v. Wisconsin, 
    347 U.S. 672
    , 682 (1954)); see also 15
    U.S.C. § 717c(a) (tasking FERC with ensuring that rates charged
    1 The defendants nevertheless point out that LDCs operating
    in New England do face some variability in demand for natural gas
    due to rapidly changing weather conditions in the region.
    - 5 -
    for sales of natural gas within FERC's jurisdiction are "just and
    reasonable").         Notwithstanding            the   comprehensiveness          of    this
    regulatory scheme, Congress also exempted wellhead sales from
    FERC's regulatory jurisdiction.                  See 
    15 U.S.C. § 3431
    (a)(1)(A).
    Accordingly, market forces dictate the wellhead price of natural
    gas.    
    Id.
     § 3431(b)(1)(A) ("[A]ny amount paid in any first sale of
    natural gas shall be deemed to be just and reasonable.").                                And
    while the NGA grants FERC regulatory authority over "sale[s] . . .
    for resale" in the spot market for natural gas, see 
    15 U.S.C. § 717
    (b),     FERC    has    issued     a    "blanket       certificate      of    public
    convenience     and       necessity"    that       allows    such     transactions        to
    proceed at market rates, see 
    18 C.F.R. § 284.402
    .
    Direct       purchasers    of       natural    gas     also   pay    for    the
    transmission of natural gas from the wellhead.                       The Algonquin Gas
    pipeline serves as the primary interstate artery through which
    natural gas is transported in New England.                        Direct purchasers in
    New England must reserve transmission capacity -- that is, the
    physical space in the pipeline needed to transport the natural gas
    purchased     from    the    producer       --    along     the    Algonquin     pipeline
    commensurate with their transportation needs.                             FERC also has
    "exclusive jurisdiction over the transportation . . . of natural
    gas    in   interstate      commerce    for       resale"     and    is    charged      with
    "determin[ing]        a     'just      and       reasonable'        rate     for       [its]
    transportation."          Schneidewind v. ANR Pipeline Co., 
    485 U.S. 293
    ,
    - 6 -
    300–01 (1988). Pursuant to this exclusive authority, FERC requires
    interstate pipeline operators like Algonquin to allow LDCs to
    purchase capacity using "no-notice" contracts.           See Order No. 636,
    
    57 Fed. Reg. 13,267
     (Apr. 16, 1992).          Such contracts allow LDCs to
    adjust capacity reservations downward or upward (up to their daily
    "firm entitlements") at any time without incurring penalties.              
    Id. at 13,286
    .      Importantly, FERC regulations allow, but do not
    require, LDCs to resell unneeded transportation capacity to other
    natural gas purchasers when they downwardly adjust their capacity
    reservations.    See 
    18 C.F.R. § 284.8
    ; Tenn. Gas Pipeline Co., 
    102 FERC ¶ 61,075
    , 61,119 (2003) ("[N]othing requires a shipper to
    release its capacity:       it does so by choice.").
    In the wholesale market for electricity, load-serving
    entities (LSEs) that sell and deliver electricity to consumers for
    retail consumption purchase electricity from power generators.
    The Federal Power Act (FPA) charges FERC with regulating these
    wholesale sales2 of electricity in interstate commerce and ensuring
    that rates in that market are "just and reasonable." See 
    16 U.S.C. §§ 824
    (b)(1),    824d(a).        In   executing   that   charge,   FERC    has
    delegated     authority     to    nonprofit      organizations,    including
    independent    system     operators    (ISOs),    to   manage   auctions   for
    wholesale electricity in the various regional markets across the
    2 A "[s]ale of electric energy at wholesale" is a "sale of
    electric energy to any person for resale." 
    16 U.S.C. § 824
    (d).
    - 7 -
    country.   Hughes v. Talen Energy Mktg., LLC, 
    136 S. Ct. 1288
    , 1292
    (2016).      ISO   New     England    (ISO-NE)      oversees    the    markets   for
    wholesale electricity in the New England region and administers
    two auctions for wholesale electricity that are relevant to this
    appeal: a same-day auction and a next-day auction to satisfy LSEs'
    short-term and near-term demand for electricity. In both auctions,
    ISO-NE accepts orders from LSEs designating the amount of energy
    they need at a given time.             Power generators then submit bids
    indicating the amount of electricity they can produce at those
    times and the price they are willing to charge for it.                      ISO-NE
    accepts    those    bids    from     lowest    to   highest    until    demand   is
    satisfied.     The price of the last accepted bid is the "clearing
    price," which sets the price paid to all the generators whose bids
    were accepted.
    Approximately     half     of    New   England's    electricity     is
    generated from natural gas power plants.               As a result, bids from
    natural gas generators usually set the clearing price for wholesale
    electricity, which then drives the retail prices charged by LSEs
    to retail consumers.         FERC does not oversee the retail sale of
    electricity.       See FERC v. Elec. Power Supply Ass'n, 
    136 S. Ct. 760
    , 766 (2016) ("[T]he law places beyond FERC's power, and leaves
    to the States alone, the regulation of 'any other sale' -- most
    notably, any retail sale -- of electricity." (citing 
    16 U.S.C. § 824
    (b)).
    - 8 -
    B.
    Defendants Eversource Energy and Avangrid, Inc. are
    energy companies that own two of the eight largest natural gas
    LDCs in New England.       They also own multiple retail electricity
    LSEs in the region.        The plaintiffs allege that the defendants
    violated   the   Sherman    Act   and    state   consumer-protection   and
    antitrust laws by artificially restricting the supply of natural
    gas in the New England transmission market.         This restriction, in
    turn, increased the cost of natural gas in the spot market, and
    led to higher wholesale electricity prices and, ultimately, higher
    retail electricity prices paid by consumers.
    According to the plaintiffs, the defendants accomplished
    this scheme by manipulating their no-notice contracts for pipeline
    transmission capacity.      By consistently reserving in advance and
    then cancelling at the end of each day significant amounts of
    transmission capacity without reselling that excess capacity to
    other LDCs or power generators, the defendants' collective conduct
    reduced the daily effective capacity along the Algonquin Gas
    pipeline by 14%, raising natural gas prices by 38% in the natural
    gas spot market, and increasing retail electricity prices by 20%.
    The defendants, who hold significant stakes in non-natural gas
    power-generating facilities, benefited from this practice because
    it artificially increased the demand for and value of these non-
    natural gas resources.      It also enabled the defendants to advocate
    - 9 -
    for the construction of costly (and allegedly unnecessary) energy
    infrastructure projects throughout New England.
    The district court dismissed the plaintiffs' claims,
    holding    that     the   filed-rate      doctrine   barred     their   federal
    antitrust and derivative state suits.                Breiding v. Eversource
    Energy, 
    344 F. Supp. 3d 433
    , 451 (D. Mass. 2018).              The "filed rate"
    upon which the district court primarily relied was FERC's approval
    of market-based rates in the electricity market administered by
    ISO-NE.    
    Id.
     at 447–48.     The court held, in the alternative, that
    plaintiffs failed to show antitrust standing and failed to plead
    a plausible claim of antitrust monopolization.             
    Id. at 456, 458
    .
    Unsatisfied with the district court's disposition of their claims,
    the plaintiffs filed this timely appeal.
    II.
    At oral argument, counsel for the plaintiffs conceded
    that the plaintiffs do not have antitrust standing to bring their
    federal antitrust damages claim.              Nevertheless, the plaintiffs
    continue    to    press   their    state-law    claims   and    their   federal
    antitrust claim for injunctive relief on appeal.               Accordingly, we
    consider    those    claims   on    the    merits,   addressing     first   the
    plaintiffs' remaining federal antitrust challenge before turning
    to the district court's disposition of the plaintiffs' state-law
    claims.    Our review is de novo.         See Abdallah v. Bain Capital LLC,
    
    752 F.3d 114
    , 119 (1st Cir. 2014).
    - 10 -
    A.
    The filed-rate doctrine is "a set of rules that have
    evolved over time but revolve around the notion that . . . utility
    filings with the regulatory agency prevail over . . . other claims
    seeking different rates or terms than those reflected in the
    filings with the agency."       Town of Norwood v. FERC, 
    217 F.3d 24
    ,
    28 (1st Cir. 2000).     "[O]nce filed, a rate may not be collaterally
    attacked in the courts."       Phillip E. Areeda & Herbert Hovenkamp,
    Antitrust Law:     An Analysis of Antitrust Principles and Their
    Application ¶ 247 (4th ed. 2019).           This rule applies with equal
    force to challenges brought "under state law and federal antitrust
    laws to rates set by federal agencies."            E. & J. Gallo Winery v.
    EnCana Corp., 
    503 F.3d 1027
    , 1033 (9th Cir. 2007).               Accordingly,
    the   doctrine   can   be   understood   as   "a   form    of   deference   and
    preemption, which precludes interference with the rate setting
    authority of an administrative agency, like FERC."               Wah Chang v.
    Duke Energy Trading & Mktg., LLC, 
    507 F.3d 1222
    , 1225 (9th Cir.
    2007).     The    filed-rate     doctrine     does   not    apply    only    to
    "traditional" rates for service; rather, it "sweeps more broadly
    and governs ancillary conditions and terms included in [a FERC-
    approved] tariff" as well.      Town of Norwood v. New Eng. Power Co.,
    
    202 F.3d 408
    , 416 (1st Cir. 2000).
    Importantly, the doctrine prohibits antitrust challenges
    to agency-approved tariffs even in energy markets in which FERC
    - 11 -
    has eschewed traditional ratemaking.      See, e.g., 
    id. at 419
    (rejecting the argument that the doctrine does not apply when
    regulated rates are left to the "free market," and observing that
    "[i]t is the filing of the tariffs, and not any affirmative
    approval or scrutiny by the agency, that triggers the filed rate
    doctrine"); Pub. Util. Dist. No. 1 of Snohomish Cty. v. Dynegy
    Power Mktg., Inc., 
    384 F.3d 756
    , 760 (9th Cir. 2004) (applying the
    doctrine to alleged anticompetitive behavior in the wholesale
    electricity market).     But cf. Town of Norwood, 
    202 F.3d at 419
    ("Of course, if [the defendant's] rates were truly left to the
    market, with no filing requirement or FERC supervision at all, the
    filed rate doctrine would by its terms no longer operate.").    In
    short, just as FERC might approve a specified rate as just and
    reasonable, it might also determine that rates produced in a
    competitive market that it oversees are just and reasonable.   The
    filed-rate doctrine applies just the same, so long as a FERC-
    approved tariff governs those market transactions.
    The plaintiffs maintained below, and argue on appeal,
    that the filed-rate doctrine should not bar their claims because
    they challenge the defendants' anticompetitive conduct in the spot
    market for natural gas, a market in which "FERC has abdicated its
    regulatory oversight."   The district court rejected that argument,
    reasoning that the plaintiffs' requested relief would require it
    to determine "the reasonableness of wholesale electricity prices
    - 12 -
    exclusively    regulated    by    FERC"   and   "the   difference   between
    wholesale     electricity    rates     during    the    class   period   and
    hypothetical rates that would have been charged but for [the
    defendants'] purported anticompetitive conduct" -- "exactly the
    analysis," according to the district court, that "the filed rate
    doctrine prohibits."      Breiding, 344 F. Supp. 3d at 447.
    We agree with the plaintiffs that the district court's
    reasoning is in some tension with our previous opinion in Town of
    Norwood.      In   that   case,   we   deemed   the    filed-rate   doctrine
    inapplicable to an antitrust challenge that alleged that a power
    generator sold its non-nuclear generating assets in order to reduce
    the supply of wholesale electricity in the New England market and
    "exert upward pressure" on wholesale electricity prices.            
    202 F.3d at
    422–23.    In doing so, we found that a FERC-issued tariff in the
    wholesale electricity market did not bar a challenge to a merger
    of generators merely because the merger affected wholesale energy
    rates.     See 
    id. at 422
    .        And in reaching that conclusion, we
    observed that though "it is not clear in all cases where the
    boundary lies between the filed rate doctrine and the default rule
    retaining antitrust liability," FERC did not have the "explicit
    power to immunize approved mergers."            Id.; see also 
    id.
     (noting
    that though "[d]irect antitrust attacks on federally regulated
    rates" and "attacks on other regulated matters underlying rates"
    "have . . . been limited by the filed rate doctrine," there is "no
    - 13 -
    across-the-board      antitrust       immunity       for        agency-approved
    transactions" (citing California v. Fed. Power Comm'n, 
    369 U.S. 482
     (1962)).     Our decision in Town of Norwood comports with the
    weight of the case law, which generally deems the filed-rate
    doctrine    inapplicable      to      challenges     to         upstream,    non-
    jurisdictional activity that indirectly affects downstream FERC-
    approved tariffs.     See, e.g., Sierra Pac. Res. v. El Paso Corp.,
    
    250 F. App'x 776
    , 777–78 (9th Cir. 2007) (finding the filed-rate
    doctrine   inapplicable      to      plaintiffs'     challenges        to   non-
    jurisdictional     "first   sales"    of   natural   gas);        E. & J.   Gallo
    Winery, 
    503 F.3d at
    1046–48 (same); cf. Brown v. Ticor Title Ins.
    Co., 
    982 F.2d 386
    , 394 (9th Cir. 1992) ("[I]f those rates were the
    product of unlawful activity prior to their being filed and were
    not subjected to meaningful review by the state, then the fact
    that they were filed does not render them immune from challenge.").
    But see Dynegy Power Mktg., 
    384 F.3d at 759
     (finding the filed-
    rate doctrine applicable when the defendant "withheld supply,
    waited until emergency conditions were declared and prices rose,
    and then offered the[] supply at [a] higher price").
    The district court's invocation of the FERC-approved
    ISO-NE   tariff,    which   governs    transactions        in    the   wholesale
    electricity market, to bar the plaintiffs' challenge to upstream
    conduct affecting the spot market for natural gas implicates
    analogous, difficult questions concerning the precise reach of the
    - 14 -
    filed-rate doctrine.             As we explain, however, the instant appeal
    does not require that we endorse or reject the broad application
    of the filed-rate doctrine espoused by the district court. Rather,
    we train our attention on a different FERC tariff that is directly
    implicated by plaintiffs' claims:                  the tariff approved for sales
    and purchases of natural gas transmission capacity.
    All of the conduct that the plaintiffs say violates
    federal and state law occurred in the natural gas transmission
    market.     Distilled to its essence, the plaintiffs' description of
    that conduct is as follows:            (1) "Eversource and Avangrid possess
    a   large    number        of    'no-notice'        contracts      for   natural      gas
    transmission     capacity          along     the     Algonquin       Pipeline";       and
    (2) "Eversource and Avangrid regularly reserved more pipeline
    capacity than they knew they needed and then, at the last minute,
    cancelled portions of their reservations" without "releas[ing]
    that   capacity,      so    that    others     could    take      advantage    of    it."
    Accordingly,     if    there       exists     any    tension      between     what    the
    plaintiffs    say     is    wrongful       conduct    and   any    agency-sanctioned
    tariff, it is most clearly and most directly with the FERC-approved
    tariffs in the natural gas transmission market.                     So, to determine
    whether the filed-rate doctrine bars the plaintiffs' claims, we
    start -- and ultimately end -- our inquiry there.
    Pursuant       to    FERC's    exclusive       authority    to    regulate
    natural gas transmission, FERC mandates that natural gas companies
    - 15 -
    file     "schedules   showing     all    rates   and    charges    for    any
    [jurisdictional] transportation or sale of natural gas." 
    18 C.F.R. § 154.1
    (b).     In addition, FERC requires operators of interstate
    natural gas pipelines like the Algonquin Gas pipeline to provide
    "'no-notice' transportation service" to ensure that LDCs are able
    to meet unexpected demand.        Order No. 636, 57 Fed. Reg. at 13,286.
    In accordance with these mandates, the FERC-approved
    tariff    for   the   Algonquin    Gas   pipeline    includes    Algonquin's
    statement of rates and rate schedule for transportation services
    along the pipeline.      See Algonquin Gas Transmission, LLC Tariff,
    pts. 4–5    [hereinafter    Algonquin     Tariff].      The     tariff   also
    addresses no-notice contracts and provides, in relevant part:
    Notwithstanding the quantities nominated by
    Customer and scheduled by Algonquin hereunder,
    Customer shall be entitled to increase its
    deliveries up to the [Maximum Daily Delivery
    Obligation] at any Primary Point(s) of
    Delivery,   up   to    the   [Maximum    Hourly
    Transportation Quantity] during any Hour, and
    up to the [Maximum Daily Transportation
    Quantity], or to decrease its deliveries.
    Provided   that   all   of   the   operational
    conditions specified in Section 5 of this rate
    schedule (the "Section 5 Conditions") are met,
    Algonquin shall consent to such increase or
    decrease in deliveries, thereby nullifying any
    daily scheduling or hourly scheduling penalty
    that would otherwise be applicable pursuant to
    Section 23   of   the    General   Terms    and
    Conditions.
    Algonquin Tariff, pt. 5, Rate Schedule AFT-E, § 4.3.            Furthermore,
    that tariff, consonant with FERC's regulations, see 18 C.F.R.
    - 16 -
    § 284.8, permits an LDC to resell its excess reserved capacity:
    "A Customer under any firm rate schedule under Part 284 may release
    all   or     a     part     of   its    capacity      under   an    Existing   Service
    Agreement . . . ."               Algonquin Tariff, pt. 6, Capacity Release,
    § 14.2.      But the tariff says nothing that would require an LDC to
    release excess capacity along the Algonquin pipeline to other
    users.
    In the plaintiffs' amended complaint, neither defendant
    is alleged to have engaged in any conduct other than that allowed
    by Algonquin's detailed and reasonably comprehensive FERC-approved
    tariff.      FERC, in conformity with its broader regulatory scheme,
    expressly declined to require direct purchasers to release excess
    capacity in recognition of the fact that direct purchasers facing
    variable demand for natural gas might need to retain that capacity
    to ensure reliability.              See, e.g., Order No. 636, 57 Fed. Reg. at
    13,269     ("[T]he          Commission       is   providing      for    a   'no-notice'
    transportation service in response to those who have expressed a
    particular concern about reliability during peak periods.").                         The
    filed-rate doctrine prohibits us from questioning that reasoned
    judgment in this lawsuit.
    All of the defendants' alleged misconduct, we might add,
    was   done       in   the    open      and   in   plain   view     of   Algonquin,   the
    defendants' competitors, and FERC.                    Furthermore, maintaining the
    efficient use of limited transmission capacity falls squarely
    - 17 -
    within the bull's-eye of FERC's regulatory aims.                    See, e.g., id.
    ("The Commission's primary aim in adopting the instant regulations
    is to improve the competitive structure of the natural gas industry
    and at the same time maintain an adequate and reliable service.").
    And Congress has given FERC the tools to police anticompetitive
    conduct in the market for transmission capacity.                The NGA makes it
    "unlawful for any entity, directly or indirectly, to use or employ,
    in connection with . . . the purchase or sale of transportation
    services subject to the jurisdiction of [FERC], any manipulative
    or deceptive device or contrivance . . . in contravention of such
    rules    and    regulations    as   [FERC]    may   prescribe."         15   U.S.C.
    § 717c-1.      All parties acknowledge that this provision and FERC's
    implementing regulation, see 18 C.F.R. § 1c.1(a), "prohibit[] the
    anticompetitive abuse of no-notice contracts" in the market for
    natural gas transmission.           Moreover, Congress empowered FERC to
    investigate and bring civil enforcement actions against willful
    and knowing violators of the NGA and FERC's regulations.                     See 15
    U.S.C. § 717t-1; see also Enf't of Statutes, Orders, Rules, &
    Regulations, 
    132 FERC ¶ 61,216
    , 62,149 (2010) (explaining that
    FERC     also     requires     disgorgement         of      "profits     illegally
    obtained . . . to those who were harmed by the violations").                    And,
    in fact, FERC did investigate the defendants' alleged manipulation
    of     their    no-notice     contracts      but    found     "no    evidence     of
    anticompetitive withholding of natural gas pipeline capacity."
    - 18 -
    News Release:     FERC Staff Inquiry Finds No Withholding of Pipeline
    Capacity in New England Markets, Fed. Energy Regulatory Comm'n (Feb. 27,
    2018), https://www.ferc.gov/media/news-releases/2018/2018-1/02-27-18.pdf.
    On appeal, the plaintiffs acknowledge that challenges to
    "practices      over   which      FERC    ha[s]   jurisdiction        and   actually
    regulate[s]" are barred pursuant to the filed-rate doctrine.                       As
    a general matter, we agree (at least in so far as those practices
    are included in a FERC-approved tariff as an exercise of FERC's
    ratemaking authority, see Town of Norwood, 
    202 F.3d at 416
    ).                      For
    this reason, it seems quite clear that the filed-rate doctrine
    precludes the plaintiffs' claims in this suit.
    The plaintiffs' principal rejoinder to this conclusion
    rests on the fact that they now seek only injunctive relief.                     They
    point to the Supreme Court's decision in Georgia v. Pa. R.R. Co.,
    
    324 U.S. 439
    ,    455   (1945)      (finding   the    filed-rate       doctrine
    inapplicable to an equitable claim that was not "a matter subject
    to    the   jurisdiction     of    the    [agency],"      did   not    request   "an
    injunction against the continuance of any tariff," and did not
    "seek to have any tariff provision cancelled").                   But in Town of
    Norwood, we explained that injunctive relief that "would require
    the alteration of [a] tariff[]" that FERC "actually scrutinized"
    is incompatible with the doctrine's purpose of "protect[ing] the
    exclusive authority of the agency to accept or challenge such
    tariffs."      
    202 F.3d at 420
    .          To rule against the defendants and
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    grant the plaintiffs' requested "order[,] enjoining defendants
    from further engaging in the unlawful conduct described in th[e]
    Complaint," a judge would need to direct, in substance and effect,
    that the defendants not hold on to excess, unused capacity without
    reselling it.      Of course, one might argue that such an order would
    not directly conflict with the tariff because the tariff does not
    actually prohibit the resale of capacity.                FERC's regulation of
    transmission       along   the      Algonquin   Gas    pipeline,    though,   is
    sufficiently comprehensive and detailed such that a judge-mandated
    elimination of the purchaser's freedom to choose whether to resell
    excess capacity would effectively overrule, or at least qualify,
    FERC's    decision    that    the    LDC's    "may"   release   their   reserved
    capacity.    Accordingly, the plaintiffs' federal antitrust claim
    fails.
    B.
    That     leaves   the     plaintiffs'     state-law    claims.    As
    already explained, the filed-rate doctrine applies with equal
    force to state-law challenges.           See E. & J. Gallo Winery, 
    503 F.3d at 1033
    .    Nor do the plaintiffs argue otherwise in their brief on
    appeal.     So, it would seem to follow from the foregoing analysis
    that dismissal of the plaintiffs' state claims is also warranted.
    We nevertheless hesitate because it is not immediately clear from
    the district court's opinion whether the court dismissed the
    plaintiffs' state claims for the same reasons that it deemed the
    - 20 -
    federal claims non-cognizable or whether the court declined to
    exercise supplemental jurisdiction over those state claims upon
    determining that the plaintiffs could not proceed with their
    federal claims, thereby leaving open the possibility that the
    plaintiffs might pursue their state claims in a separate action in
    state court.
    On the one hand, the district court made clear that the
    filed-rate doctrine barred both the plaintiffs' federal and state-
    law claims, see Breiding, 344 F. Supp. 3d at 451 ("[T]he Court
    holds that the doctrine bars the federal and state law claims in
    the   amended     complaint."),   and   went   on   to   conclude   that   the
    plaintiffs' alleged injuries were "too remote to satisfy the
    causation prongs of the various state law claims," id. at 459.              On
    the other hand, the district court concluded its opinion with the
    following statement:       "[T]he Court, for the reasons previously
    mentioned, has dismissed all of Plaintiffs' federal claims and
    declines to exercise jurisdiction over the remaining state law
    claims."    Id.    The district court then entered an order dismissing
    the plaintiffs' complaint without mentioning whether the dismissal
    was with prejudice or not. The district court also made no mention
    of    the   plaintiffs'   alternative       invocation    of   federal-court
    jurisdiction under the Class Action Fairness Act (CAFA), 
    28 U.S.C. § 1332
    (d)(2) (creating original jurisdiction over class actions
    - 21 -
    with     minimal   diversity    and   aggregate   damages   that   exceed
    $5,000,000).
    We construe the district court's opinion as dismissing
    the plaintiffs' state-law claims on the merits, notwithstanding
    the court's mixed signals, for the following reasons.         First, the
    district court, in "declin[ing] to exercise jurisdiction over the
    remaining state law claims," appeared to do so as an alternative
    basis for dismissing those challenges, perhaps in contemplation of
    the possibility that we might disagree with its application of the
    filed-rate doctrine to the plaintiffs' claims.          See 
    id. at 458
    ("Although the filed rate doctrine applies with equal force to
    Plaintiffs' state law claims, the Court concludes that Plaintiffs'
    state law claims also fail for the reasons stated below." (citation
    omitted)).      Having concluded that the filed-rate doctrine does,
    indeed, bar all the plaintiffs' claims, we have no need to reach
    the district court's alternative bases for dismissal.
    Second, it would have made little sense to decline to
    exercise supplemental jurisdiction over the residual state-law
    claims    for   purposes   of   dismissing   them   after   finding   the
    plaintiffs' federal claims non-cognizable due to the filed-rate
    doctrine.    To be sure, normally "the unfavorable disposition of a
    plaintiff's federal claims at the early stages of a suit . . .
    will trigger the dismissal without prejudice of any supplemental
    state-law claims."     Rodriguez v. Doral Mortg. Corp., 
    57 F.3d 1168
    ,
    - 22 -
    1177 (1st Cir. 1995).              But "[i]n an appropriate situation, a
    federal    court       may    retain    jurisdiction        over    state-law          claims
    notwithstanding         the    early    demise      of   all    foundational          federal
    claims."        
    Id.
         In deciding whether to do so, federal courts
    consider       "the      interests       of      fairness,        judicial         economy,
    convenience, and comity."              Camelio v. Am. Fed'n, 
    137 F.3d 666
    , 672
    (1st Cir. 1998).              Here, the interests of fairness, judicial
    economy,       and    convenience       all     support     retaining         jurisdiction
    because the survival of the plaintiffs' state and federal claims
    hinges    on    an    application       of    the   filed-rate      doctrine          to    the
    plaintiffs' complaint. That the doctrine applies with equal effect
    and   vigor     to    the     plaintiffs'       state-law      claims,        in   turn,     is
    effectively undisputed. Furthermore, in order to affirm a decision
    to decline supplemental jurisdiction, we would first need to
    determine      whether       original    jurisdiction          exists    under      CAFA,    a
    matter not briefed by the parties. Finally, retaining jurisdiction
    to dismiss the state-law claims would raise no comity concerns
    because    the       dismissal   of     those    claims     would       not    turn    on    an
    application of state law.
    Having so construed the district court's opinion, we
    find that the plaintiffs' state-law challenges are also barred by
    the filed-rate doctrine for the reasons described above.
    - 23 -
    III.
    Because we find that all of the plaintiffs' claims are
    defeated by application of the filed-rate doctrine, we affirm the
    district court's dismissal of the plaintiffs' federal antitrust
    and   state-law   claims.   Nothing     in   this   holding   approves   or
    disapproves of any of the defendants' conduct.           We simply hold
    that the plaintiffs' allegations, assuming their truth, describe
    an issue for FERC to address.
    - 24 -