                 FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


JOSEPH A. PAKOOTAS, an individual          No. 16-35742
and enrolled member of the
Confederated Tribes of the Colville           D.C. No.
Reservation; DONALD R. MICHEL, an          2:04-cv-00256-
individual and enrolled member of               LRS
the Confederated Tribes of the
Coville Reservation; CONFEDERATED
TRIBES OF THE COLVILLE                       OPINION
RESERVATION,
                 Plaintiffs-Appellees,

STATE OF WASHINGTON,
       Intervenor-Plaintiff-Appellee,

                  v.

TECK COMINCO METALS, LTD., a
Canadian corporation,
              Defendant-Appellant.



      Appeal from the United States District Court
        for the Eastern District of Washington
       Lonny R. Suko, District Judge, Presiding

        Argued and Submitted February 5, 2018
                 Seattle, Washington

                Filed September 14, 2018
2           PAKOOTAS V. TECK COMINCO METALS

    Before: Ronald M. Gould and Richard A. Paez, Circuit
      Judges, and Michael J. McShane, * District Judge.

                    Opinion by Judge Gould


                          SUMMARY **


                      Environmental Law

   The panel affirmed the district court’s judgment, after
two phases of a trifurcated bench trial, in favor of plaintiffs
in an action under the Comprehensive Environmental
Response, Compensation, and Liability Act.

    The district court dismissed defendant Teck Cominco
Metals’ divisibility defense to joint and several liability on
summary judgment. At Phase I of the trifurcated trial, the
district court held that Teck was liable as an “arranger” under
CERCLA § 107(a)(3). At Phase II, the district court found
Teck liable for more than $8.25 million of plaintiff Colville
Tribes’ response costs. The district court then certified this
appeal by entering partial judgment under Federal Rule of
Civil Procedure 54(b).

    The panel held that it had jurisdiction to entertain the
appeal. The panel concluded that Rule 54(b) authorized the
district court to certify the appeal because the district court

     *
      The Honorable Michael J. McShane, United States District Judge
for the District of Oregon, sitting by designation.
    **
       This summary constitutes no part of the opinion of the court. It
has been prepared by court staff for the convenience of the reader.
           PAKOOTAS V. TECK COMINCO METALS                    3

rendered an ultimate disposition of an individual claim by
ruling on Colville Tribes’ response costs claim, which was
separable from the Tribes’ claim for natural resource
damages. The panel held that the district court’s Rule 54(b)
certification was not an abuse of discretion.

    The panel held that the district court properly exercised
personal jurisdiction over Teck, operator of a lead and zinc
smelter in British Columbia. The panel applied the Calder
“effects” test because the claims for recovery of response
costs and natural resource damages were akin to a tort claim.
The panel held that, under the Calder test, Teck purposefully
directed its activities toward Washington State.

    The panel held that the district court properly awarded
the Colville Tribes their investigation costs incurred in
establishing Teck’s liability. CERCLA § 107(a)(4)(A)
provides that a potentially responsible party, or PRP, is liable
for “all costs of removal or remedial action.” The panel held
that investigations by the Tribes’ expert consultants
qualified as recoverable costs of removal, even though many
of these activities played double duty supporting both
cleanup and litigation efforts.

    The panel held that § 107(a)(4)(A) also allowed the
Tribes to recover their attorneys’ fees as part of their
response costs. The panel held that the district court did not
abuse its discretion in setting the amount of attorneys’ fees.

    The panel affirmed the district court’s grant of summary
judgment rejecting Teck’s divisibility defense to joint and
several liability. The panel concluded that there was no
triable issue whether Teck had sufficient evidence to prove
the defense, which requires a showing that the
environmental harm is theoretically capable of
4        PAKOOTAS V. TECK COMINCO METALS

apportionment and that the record provides a reasonable
basis on which to apportion liability.


                     COUNSEL

Kevin Murray Fong (argued), Pillsbury Winthrop Shaw
Pittman LLP, San Francisco, California; Christopher J.
McNevin, Pillsbury Winthrop Shaw Pittman LLP, Austin,
Texas; for Defendant-Appellant.

Paul Jerome Dayton (argued) and Brian S. Epley, Short
Cressman & Burgess PLLC, Seattle, Washington; for
Plaintiffs-Appellees.

Andrew Arthur Fitz (argued), Senior Counsel; Robert W.
Ferguson, Attorney General; Kelly T. Wood, Assistant
Attorney General; Office of the Washington Attorney
General,   Olympia, Washington; Intervenor-Plaintiff-
Appellee.
           PAKOOTAS V. TECK COMINCO METALS                   5

                         OPINION

GOULD, Circuit Judge:

    This appeal is the latest chapter in a multi-decade dispute
centered on Teck Metals’ liability for dumping several
million tons of industrial waste into the Columbia River.
Since we last heard an interlocutory appeal in this case, the
district court dismissed Teck’s divisibility defense to joint
and several liability on summary judgment. At Phase I of
the trifurcated bench trial, the court held that Teck was a
liable party under the Comprehensive Environmental
Response, Compensation, and Liability Act (“CERCLA”).
At Phase II, the court found Teck liable for more than
$8.25 million of the Confederated Tribes of the Colville
Reservation’s response costs. The district court then
certified this appeal by entering partial judgment under
Federal Rule of Civil Procedure 54(b). We conclude that we
have jurisdiction, and we affirm.

                              I

    The Columbia River, the fourth-largest river in North
America, begins its 1,200-mile journey to the sea from its
headwaters in the Canadian Rockies. The River charts a
northwest course in British Columbia before bending south
toward Washington. It then widens and forms the Arrow
Lakes reservoir until, thirty miles before the international
border, it reaches the Hugh Keenleyside Dam. After passing
through the dam’s outlet, the River is free-flowing until
south of the border near Northport, Washington. There it
again starts to slow and pool at the uppermost reaches of
Lake Roosevelt, the massive reservoir impounded behind
the Grand Coulee Dam. This case concerns the more than
150-mile stretch of river between the Canadian border and
6             PAKOOTAS V. TECK COMINCO METALS

the Grand Coulee Dam, known as the Upper Columbia
River.

    From time immemorial, the Upper Columbia River has
held great significance to the Confederated Tribes of the
Colville Reservation. These tribes historically depended on
the River’s plentiful fish for their survival and gave the River
a central role in their cultural traditions. 1 And the Colville
Tribes continue to use the Upper Columbia River to this day
for fishing and recreation. Under the applicable treaties, the
Tribes retain fishing rights in the River up to the Canadian
border. See Okanogan Highlands All. v. Williams, 236 F.3d
468, 478 (9th Cir. 2000) (citing Antoine v. Washington,
420 U.S. 194, 196 n.4 (1975)). Those treaties draw the
Colville Reservation’s eastern and southern boundaries “in
the middle of the channel of the Columbia River.” Act of
July 1, 1892, ch. 140, § 1, 27 Stat. 62, 62–63. The Tribes
claim equitable title to the riverbed on their side of the
channel, and the United States has long supported this claim.
See Confederated Tribes of Colville Reservation v. United
States, 964 F.2d 1102, 1105 n.7 (Fed. Cir. 1992); Opinion on
the Boundaries of and Status of Title to Certain Lands Within
the Colville and Spokane Indian Reservations, 84 Interior
Dec. 72, 75–80, 1977 WL 28859, at *3–5.

    For nearly a century, however, the Upper Columbia
River has been fouled by Teck Metals’ toxic waste. 2 Teck
operates the world’s largest lead and zinc smelter in Trail,
British Columbia, just ten miles upstream of the U.S. border.
    1
      See generally U.S. EPA, Upper Columbia River Expanded Site
Inspection Report Northeast Washington, app. A (Petition for
Assessment of Release), https://nepis.epa.gov/Exe/ZyPURL.cgi?Docke
y=P100MFOQ.TXT.

    2
        Teck was previously named Teck Cominco Metals.
            PAKOOTAS V. TECK COMINCO METALS                           7

During smelting, lead or zinc ore is heated to a molten state,
during which the desired metal is separated from impurities
in the raw ore. These impurities cool to form glassy,
granular slag. Between 1930 and 1995, Teck discharged
about 400 tons of slag daily—an estimated 9.97 million tons
in total—directly into the free-flowing Columbia River.
Teck washed this debris into the river using untold gallons
of contaminated effluent. These solid and liquid wastes
contained roughly 400,000 tons (800 million pounds) of the
heavy metals arsenic, cadmium, copper, lead, mercury, and
zinc, in addition to lesser amounts of other hazardous
substances. 3

    At least 8.7 million tons of the Trail smelter’s slag and
nearly all of the dissolved and particulate-bound metals in its
effluent made the short trip downstream into the United
States. Upon reaching the calmer waters of Lake Roosevelt,
Teck’s smelting byproducts came to rest on the riverbed and
banks, with larger detritus settling upstream and smaller
particles settling downstream near the Grand Coulee Dam. 4



    3
      Teck’s slag contained 255,000 tons of zinc (510 million pounds)
and 7,300 tons of lead (14.6 million pounds). Teck’s effluent contained
an additional 108,000 tons of zinc (216 million pounds), 22,000 tons of
lead (44 million pounds), 1,700 tons of cadmium (3.4 million pounds),
270 tons of arsenic (540,000 pounds), and 200 tons of mercury (400,000
pounds). The district court did not make a finding on how much copper
Teck dumped into the river, but Teck previously conceded that about
29,000 tons (58 million pounds) reached the Upper Columbia River.

    4
       Black Sand Beach, for instance, is named after the sand-like slag
deposits that have accumulated on the riverbank near Northport,
Washington. See URS Corp., Completion Report & Performance
Monitoring Plan: Black Sand Beach Project § 2.2 (2011),
https://fortress.wa.gov/ecy/gsp/DocViewer.ashx?did=3783.
8          PAKOOTAS V. TECK COMINCO METALS

Once settled, these wastes began to break down and release
hazardous substances into the River’s waters and sediment.

    In 1999, the Colville Tribes petitioned the U.S.
Environmental Protection Agency to assess the threats posed
by the contamination of the Upper Columbia River Site.
Two years later the Tribes and EPA signed an
intergovernmental agreement coordinating a site
investigation and assessment.         After completing its
preliminary assessment, EPA issued a unilateral
administrative order against Teck. The order directed Teck
to perform a remedial investigation and feasibility study
(“RI/FS”) of the Site under CERCLA. Teck disputed
whether it was subject to CERCLA, however, and EPA
decided not to enforce the order during negotiations with the
company.

    The Colville Tribes then tried to enforce EPA’s order by
funding a CERCLA citizen suit by two of their tribal
government officials in 2004. These plaintiffs were later
joined by the State of Washington as a plaintiff-intervenor
and eventually by the Colville Tribes as a co-plaintiff.

    Teck moved to dismiss the action. It primarily argued
that CERCLA does not apply extraterritorially to its
activities and that it cannot be held liable as a person who
“arranged for disposal” of hazardous substances. The
district court denied this motion to dismiss and certified the
issues for immediate appeal under 28 U.S.C. § 1292(b).

    While the appeal was pending, Teck and EPA entered a
settlement agreement withdrawing EPA’s order and
committing Teck to fund and conduct an RI/FS modeled on
CERCLA’s requirements. The study aims to investigate the
extent of contamination at the Site, to provide information
for EPA’s assessment of the risk to human health and the
            PAKOOTAS V. TECK COMINCO METALS                         9

environment, and to evaluate potential remedial alternatives.
But the settlement agreement is silent as to Teck’s
responsibility for cleaning up the Site.

    We accepted Teck’s interlocutory appeal and affirmed
the district court’s denial of the motion to dismiss. See
Pakootas v. Teck Cominco Metals, Ltd., 452 F.3d 1066, 1082
(9th Cir. 2006) (Pakootas I). We held that the suit did not
involve an extraterritorial application of CERCLA because
Teck’s pollution had “come to be located” in the United
States. Id. at 1074 (quoting 42 U.S.C. § 9601(9)). We also
held that the complaint had stated a claim for relief because
the actual or threatened release of hazardous substances at
the Site could subject Teck to “arranger” liability under
CERCLA. Id. at 1082 (citing 42 U.S.C. § 9607(a)(3)).

    On remand, the Tribes and the State each filed amended
complaints seeking cost recovery, natural resource damages,
and related declaratory relief under CERCLA. 5 Litigation
was ultimately trifurcated into three phases to sequentially
determine: (1) whether Teck is liable as a potentially
responsible party (“PRP”); (2) Teck’s liability for response
costs; and (3) Teck’s liability for natural resource damages.

    Before the first bench trial, the Tribes and the State
moved for partial summary judgment on Teck’s divisibility
defense. The district court granted the motions and
dismissed the defense, concluding that Teck did not present
enough evidence to create a genuine issue of fact as to
whether the environmental harm to the Upper Columbia

    5
     The individual plaintiffs’ claims were subsequently dismissed and
judgment was entered against them, which we affirmed on appeal.
Pakootas v. Teck Cominco Metals, Ltd., 646 F.3d 1214, 1225 (9th Cir.
2011) (Pakootas II).
10           PAKOOTAS V. TECK COMINCO METALS

River was theoretically capable of apportionment or whether
there was a reasonable basis for apportioning Teck’s share
of liability.

    In Phase I of trial, the district court concluded that Teck
was liable as an arranger under CERCLA section 107(a)(3),
42 U.S.C. § 9607(a)(3). In doing so, the court rejected
Teck’s argument that Washington courts lack personal
jurisdiction over the company. The district court then held
that without its divisibility defense, Teck was jointly and
severally liable to the Tribes and the State under section
107(a)(4)(A), 42 U.S.C. § 9607(a)(4)(A). 6

    In Phase II, the State settled its claim for past response
costs while the Tribes proceeded to trial. The district court
found in favor of the Tribes and awarded them
$3,394,194.43 in investigative expenses incurred through
December 31, 2013, $4,859,482.22 in attorney’s fees up to
that date, and $344,300.00 in prejudgment interest. The
court then directed the entry of judgment on Teck’s liability
for these response costs under Federal Rule of Civil
Procedure 54(b).

    Teck now appeals from the district court’s summary
judgment order and partial judgment on the first two phases
of trial.




     6
      After the Phase I bench trial, the Tribes and the State filed amended
complaints adding allegations that the Trail smelter’s air emissions also
resulted in the discharge of hazardous substances at the Site. The district
court denied the motion to strike those allegations, but we reversed on
appeal. Pakootas v. Teck Cominco Metals, Ltd., 830 F.3d 975, 986 (9th
Cir. 2016) (Pakootas III).
            PAKOOTAS V. TECK COMINCO METALS                         11

                                  II

    We first consider whether we have jurisdiction to
entertain this appeal.

                                  A

    Teck contends, as an initial matter, that Rule 54(b) did
not authorize the district court to certify this appeal by
entering partial final judgment. Rule 54(b) allows a district
court in appropriate circumstances to enter judgment on one
or more claims while others remain unadjudicated. 7 To do
so, the district court first must render “an ultimate
disposition of an individual claim.” Curtiss-Wright Corp. v.
Gen. Elec. Co., 446 U.S. 1, 7 (1980) (quoting Sears, Roebuck
& Co. v. Mackey, 351 U.S. 427, 436 (1956)). The court then
must find that there is no just reason for delaying judgment
on this claim. Id. at 8.

    According to Teck, the district court had to await the
conclusion of this entire multi-decade litigation before
entering judgment on the Tribes’ response costs claim. Teck
reasons that the Tribes actually raise a single CERCLA
claim—for arranger liability—with multiple remedies:
recovery of response costs and natural resource damages.

    What constitutes an individual “claim” is not well
defined in our law. The Supreme Court has expressly
declined to “attempt any definitive resolution of the meaning
of” the term, Liberty Mut. Ins. Co. v. Wetzel, 424 U.S. 737,

    7
      In relevant part, the Rule provides: “When an action presents more
than one claim for relief . . . , the court may direct entry of a final
judgment as to one or more, but fewer than all, claims . . . only if the
court expressly determines that there is no just reason for delay.” Fed.
R. Civ. P. 54(b).
12         PAKOOTAS V. TECK COMINCO METALS

743 n.4 (1976), and its “judicial crumbs have failed to lead
the circuit courts to a consensus as to the handling of this
confusing area of law,” Eldredge v. Martin Marietta Corp.,
207 F.3d 737, 741 (5th Cir. 2000). In this circuit, we have
often tried to avoid this jurisprudential quagmire by
employing a “pragmatic approach.” Cont’l Airlines, Inc. v.
Goodyear Tire & Rubber Co., 819 F.2d 1519, 1525 (9th Cir.
1987); cf. 15A Charles Alan Wright, Arthur R. Miller &
Edward H. Cooper, Federal Practice and Procedure:
Jurisdiction § 3914.7 (2d ed. 2018) (“[T]he policies
underlying Rule 54(b) are not well served, and certainly are
not well explained, by reliance on efforts to define a
claim.”).

    At the doctrine’s outer edges, however, our cases have
given some guidance. Rule 54(b)’s use of the word “claim”
at minimum refers to “a set of facts giving rise to legal rights
in the claimant.” CMAX, Inc. v. Drewry Photocolor Corp.,
295 F.2d 695, 697 (9th Cir. 1961). Multiple claims can thus
exist if a case joins multiple sets of facts. See, e.g., Purdy
Mobile Homes, Inc. v. Champion Home Builders Co.,
594 F.2d 1313, 1316 (9th Cir. 1979). Conversely, only one
claim is presented when “a single set of facts giv[es] rise to
a legal right of recovery under several different remedies.”
Ariz. State Carpenters Pension Tr. Fund v. Miller, 938 F.2d
1038, 1040 (9th Cir. 1991).

    In Arizona State Carpenters Pension Trust Fund, for
example, we identified a single claim under Rule 54(b)
because a single set of facts gave rise to both a count for
punitive damages and a count for compensatory damages.
Id. The plaintiff’s count for punitive damages required all
the same facts as its count for compensatory damages, plus
additional proof of an aggravating factor. Id. Because the
showing required for punitive damages completely
           PAKOOTAS V. TECK COMINCO METALS                  13

encompassed that required for compensatory damages, we
considered these counts to be an indivisible claim for
Rule 54(b)’s purposes. See id. We thus forbade the
immediate appeal of a ruling dismissing only the punitive
damages claim, which necessarily would have become moot
if the lesser-included count for compensatory damages later
failed as well. See id.

    Nevertheless, a challenger “cannot successfully attack
the court’s finding of multiple claims merely by showing
that some facts are common to all of its theories of
recovery.” Purdy Mobile Homes, 594 F.2d at 1316 (internal
quotation marks omitted).            Claims with partially
“overlapping facts” are not “foreclosed from being separate
for purposes of Rule 54(b).” Wood v. GCC Bend, LLC,
422 F.3d 873, 881 (9th Cir. 2005). Instead, a district court
can enter final judgment on a claim even if it is not “separate
from and independent of the remaining claims.” Texaco,
Inc. v. Ponsoldt, 939 F.2d 794, 797 (9th Cir. 1991) (quoting
Sheehan v. Atlanta Int’l Ins. Co., 812 F.2d 465, 468 (9th Cir.
1987)). And such a judgment is permissible even if the claim
“arises out of the same transaction and occurrence as
pending claims.” Cold Metal Process Co. v. United Eng’g
& Foundry Co., 351 U.S. 445, 452 (1956).

    Here, the Colville Tribes’ counts for response costs and
for natural resource damages present multiple claims
because each requires a factual showing not required by the
other. See Purdy Mobile Homes, 594 F.2d at 1316; cf. also
Blockburger v. United States, 284 U.S. 299, 304 (1932)
(holding that for the purposes of the Double Jeopardy
Clause, “the test to be applied to determine whether there are
two offenses or only one, is whether each provision requires
14           PAKOOTAS V. TECK COMINCO METALS

proof of a fact which the other does not”). 8 Both response
cost and natural resource damages claims require proof that
(1) the defendant falls within one of the four classes of PRPs
listed in section 107(a), 42 U.S.C. § 9607(a); (2) the site on
which hazardous substances are found is a “facility” within
the meaning of section 101(9), id. § 9601(9); and (3) a
“release” or “threatened release” of a hazardous substance
from the facility has occurred. See id. § 9607(a); Pakootas
III, 830 F.3d at 981. But a government’s claim for response
costs must also show that (4) the government has incurred
costs responding to the release or threatened release; and
(5) those costs are “not inconsistent with the national
contingency plan,” which is assumed to be the case absent a
defendant’s proof to the contrary. 42 U.S.C. § 9607(a)(4),
(4)(A). By contrast, a claim for natural resource damages
instead must show that (4) natural resources under the
plaintiff’s trusteeship have been injured and (5) the injury to
natural resources “result[ed] from” the release or threatened
release of the hazardous substance.                  42 U.S.C.
§ 9607(a)(4)(C); Pakootas III, 830 F.3d at 981 n.4. The text
of CERCLA elsewhere suggests the conclusion that these
two claims are distinct, describing them as separate
“[a]ctions for recovery of costs” and “[a]ctions for natural
resource damages,” and imposing different limitations
periods in which those actions may be brought. 42 U.S.C.
§ 9613(g)(1)–(2).




     8
      See also Samaad v. City of Dallas, 940 F.2d 925, 931 n.10 (5th Cir.
1991) (noting that our approach in Purdy Mobile Homes “bears a striking
similarity to that employed in the double jeopardy context” under
Blockburger), abrogated on other grounds by Stop the Beach
Renourishment, Inc. v. Fla. Dep’t of Envtl. Prot., 560 U.S. 702, 728
(2010).
           PAKOOTAS V. TECK COMINCO METALS                  15

    In situations like this, where a suit involves multiple
claims, we leave it to the district court, as “dispatcher,”
Curtiss-Wright, 446 U.S. at 8 (quoting Sears, Roebuck &
Co., 351 U.S. at 435), to evaluate the “interrelationship of
the claims” and determine in the first instance “whether the
claims under review [are] separable from the others
remaining to be adjudicated.” Id. at 8, 10. In doing so, “a
district court must take into account judicial administrative
interests as well as the equities involved.” Id. at 8. We
review the district court’s decision to enter final judgment
under Rule 54(b) for abuse of discretion. See id.

    Although no party disputes the district court’s exercise
of discretion in this case, we must review it to satisfy
ourselves that we have subject matter jurisdiction to hear this
appeal. See Sheehan, 812 F.2d at 468. Having done so, we
conclude that there was no abuse of discretion. This is a
complex case that has been ongoing for fourteen years, and
the entry of partial judgment against Teck would help ensure
that a responsible party promptly pays for the contamination
of the Upper Columbia River, advancing CERCLA’s goals
and easing the Tribes’ burden of financing the litigation
effort. See Wood, 422 F.3d at 882. We hold that the district
court’s Rule 54(b) certification here was appropriate.

                              B

    Teck also raises two challenges to the district court’s
exercise of personal jurisdiction over the company. First,
Teck argues that the district court should not have applied
the so-called “effects” test of Calder v. Jones, 465 U.S. 783
(1984). In the alternative, Teck argues that the Calder test
was not satisfied because the Trail smelter’s discharges into
the Columbia River were not expressly aimed at
Washington.
16         PAKOOTAS V. TECK COMINCO METALS

    We assess specific personal jurisdiction using a three-
prong test. See Yahoo! Inc. v. La Ligue Contre Le Racisme
Et L’Antisemitisme, 433 F.3d 1199, 1205–06 (9th Cir. 2006)
(en banc). Under the first prong, the Colville Tribes must
show either that Teck purposefully availed itself of the
privilege of conducting activities in Washington, or that it
purposefully directed its activities toward Washington. See
Schwarzenegger v. Fred Martin Motor Co., 374 F.3d 797,
802 (9th Cir. 2004). A “purposeful availment” analysis is
used for cases sounding in contract. Id. By contrast, a
“purposeful direction” analysis under Calder “is most often
used in suits sounding in tort.” Id. at 802–03.

    The Calder test plainly applies here. Claims for recovery
of response costs and natural resource damages are “more
akin to a tort claim than a contract claim.” Ziegler v. Indian
River Cty., 64 F.3d 470, 474 (9th Cir. 1995); see also E.I. Du
Pont de Nemours & Co. v. United States, 365 F.3d 1367,
1373 (Fed. Cir. 2004) (“CERCLA evolved from the doctrine
of common law nuisance.”). Besides, CERCLA liability for
toxic pollution is much closer to the traditional domain of
common law torts than several of the other areas in which
we have applied Calder’s effects test. See, e.g., Brayton
Purcell LLP v. Recordon & Recordon, 606 F.3d 1124, 1128
(9th Cir. 2010) (copyright infringement); Yahoo! Inc.,
433 F.3d at 1206 (foreign court order enforcement);
Panavision Int’l, L.P. v. Toeppen, 141 F.3d 1316, 1321 (9th
Cir. 1998) (trademark dilution).

    We construe Calder as imposing three requirements:
“the defendant allegedly must have (1) committed an
intentional act, (2) expressly aimed at the forum state,
(3) causing harm that the defendant knows is likely to be
suffered in the forum state.” Yahoo!, 433 F.3d at 1206
           PAKOOTAS V. TECK COMINCO METALS                  17

(alteration in original) (quoting Schwarzenegger, 374 F.3d at
803).

     Teck argues only that its waste disposal activities were
not “expressly aimed” at Washington. Express aiming is an
ill-defined concept that we have taken to mean “something
more” than “a foreign act with foreseeable effects in the
forum state.” Bancroft & Masters, Inc. v. Augusta Nat. Inc.,
223 F.3d 1082, 1087 (9th Cir. 2000).

    Calder illustrates this point. In that case, a California
actress sued two National Enquirer employees for an
allegedly defamatory article published in the magazine. The
article had been written and edited in Florida but the
magazine was distributed nationally, with its largest market
in California. The Supreme Court upheld the exercise of
personal jurisdiction in California because the allegations of
libel did not concern “mere untargeted negligence” with
foreseeable effects there; rather, the defendants’
“intentional, and allegedly tortious, actions were expressly
aimed” at the state. 465 U.S. at 789. Those actions simply
involved writing and editing an article about a person in
California, an article that the defendants knew would be
circulated and cause reputational injury in that forum. Id. at
789–90. Under those circumstances, the defendants should
“reasonably anticipate being haled into court there” to
answer for their tortious behavior. Id. at 790 (quoting
World-Wide Volkswagen Corp. v. Woodson, 444 U.S. 286,
297 (1980)). That was true even though the defendants were
not personally responsible for the circulation of their article
in California. Id. at 789–90.

   We have no difficulty concluding that Teck expressly
aimed its waste at the State of Washington. The district court
found ample evidence that Teck’s leadership knew the
Columbia River carried waste away from the smelter, and
18         PAKOOTAS V. TECK COMINCO METALS

that much of this waste travelled downstream into
Washington, yet Teck continued to discharge hundreds of
tons of waste into the river every day. It is inconceivable
that Teck did not know that its waste was aimed at the State
of Washington when Teck deposited it into the powerful
Columbia River just miles upstream of the border. As early
as the 1930s, Teck knew that its slag had been found on the
beaches of the Columbia River south of the United States
border. By the 1980s, Teck’s internal documents recognized
that its waste was having negative effects on Washington’s
aquatic ecosystem. And by the early 1990s, Teck’s
management acknowledged that the company was “in effect
dumping waste into another country,” using the Upper
Columbia River as a “free” and “convenient disposal
facility.” But still Teck, over and over again, on a daily basis
for decades, dumped its waste into the river until it
modernized its furnace in the mid-1990s.

    It is no defense that Teck’s wastewater outfalls were
aimed only at the Columbia River, which in turn was aimed
at Washington. Rivers are nature’s conveyor belts. Teck
simply made use of the river’s natural transport system
throughout the 1900s, much like lumberjacks of that period
who would roll timber into a stream to start a log drive.
Without this transport system, Teck would have soon been
inundated by the massive quantities of waste it produced—
which, it bears repeating, averaged some 400 tons per day.
Teck’s connection with Washington was not “random,”
“fortuitous,” or “attenuated,” Burger King Corp. v.
Rudzewicz, 471 U.S. 462, 475 (1985) (internal quotation
marks omitted), nor would the maintenance of this suit
offend “traditional conception[s] of fair play and substantial
justice,” id. at 464 (alteration in original) (quoting Int’l Shoe
Co. v. Washington, 326 U.S. 310, 320 (1945)). To the
contrary, there would be no fair play and no substantial
           PAKOOTAS V. TECK COMINCO METALS                  19

justice if Teck could avoid suit in the place where it
deliberately sent its toxic waste. We hold that personal
jurisdiction over Teck exists in Washington.

                             III

    Satisfied that we have jurisdiction, we now turn to
Teck’s argument that CERCLA does not allow the Colville
Tribes to recover their costs of establishing Teck’s liability.
The district court awarded the Tribes more than $8.25
million in costs incurred through December 31, 2013,
consisting of about $3.39 million in investigation expenses
plus $4.86 million in attorney’s fees and costs. The court
deemed the Tribes’ investigation to be recoverable as part of
a “removal” action, and characterized their attorney’s efforts
as “enforcement activities.” We consider each part of the
district court’s award below, reviewing its findings of fact
for clear error and its conclusions of law de novo. Kirola v.
City & Cty. of San Francisco, 860 F.3d 1164, 1174 (9th Cir.
2017).

                              A

    We first review the district court’s award of the Colville
Tribes’ investigation costs.

                              1

    Section 107(a)(4)(A) of CERCLA provides that a PRP is
liable for “all costs of removal or remedial action incurred
by the United States Government or a State or an Indian tribe
not inconsistent with the national contingency plan.”
42 U.S.C. § 9607(a)(4)(A). At its core, a “removal” action
is defined as “the cleanup or removal” of hazardous
20           PAKOOTAS V. TECK COMINCO METALS

substances from the environment. 9 Id. § 9601(23). No less
important, however, are several associated activities
described by the statutory definition. 10 This case concerns
two defined categories of related activities: such efforts “as
may be necessary to monitor, assess, and evaluate the release
or threat of release of hazardous substances,” and “as may
be necessary to prevent, minimize, or mitigate damage to the
public health or welfare or to the environment.” Id.

    Cleanup-adjacent activities face a low bar to satisfying
these definitions of “removal.” See United States v. W.R.
Grace & Co., 429 F.3d 1224, 1238 (9th Cir. 2005) (“The
definition of ‘removal’ is written in sweeping terms.”).
Section 101(23) covers all activities “as may be necessary”
to advance certain threat assessment or abatement goals.
This permissive language means qualifying activities need
not be performed with the intent of achieving the statutory
goals; need not be absolutely necessary to achieve those
goals; and need not actually achieve those goals. Rather,

     9
       To clarify our terminology, we note that “Congress intended that
there generally will be only one removal action,” of which different
activities are just a part. Kelley v. E.I. DuPont de Nemours & Co.,
17 F.3d 836, 843 (6th Cir. 1994); see also Brian Block, Remediating
CERCLA’s Polluted Statute of Limitations, 13 Rutgers J.L. & Pub. Pol’y
388, 400 (2016) (collecting cases).

     10
        Section 101(23) defines “removal” as “[1] the cleanup or removal
of released hazardous substances from the environment, [2] such actions
as may be necessary taken in the event of the threat of release of
hazardous substances into the environment, [3] such actions as may be
necessary to monitor, assess, and evaluate the release or threat of release
of hazardous substances, [4] the disposal of removed material, or [5] the
taking of such other actions as may be necessary to prevent, minimize,
or mitigate damage to the public health or welfare or to the environment,
which may otherwise result from a release or threat of release.”
42 U.S.C. § 9601(23).
           PAKOOTAS V. TECK COMINCO METALS                  21

taking a cue from the D.C. Circuit’s construction of “as may
be necessary” in the Communications Act of 1934, we hold
that the definitions of “removal” reach all acts that “are not
an unreasonable means” of furthering section 101(23)’s
enumerated ends. Cellco P’ship v. FCC, 357 F.3d 88, 91
(D.C. Cir. 2004) (quoting FCC v. Nat’l Citizens Comm. for
Broad., 436 U.S. 775, 796 (1978)).

                              2

    The district court concluded that the investigations by the
Tribes’ expert consultants qualify as recoverable costs of
removal. To begin with, the Tribes hired an environmental
consultant, Environment International, to plan and
implement a study of the Upper Columbia River Site. This
consultant collected multiple sediment and pore water
samples and sent those samples to independent labs for
testing. An environmental engineering firm, LimnoTech,
then compiled the resulting data into a comprehensive
database and analyzed the data. The Tribes also employed
several subject-matter experts, such as a geochemist and a
metallurgist, to review the data. Finally, the Tribes retained
a hydrology firm, Northwest Hydraulic Consultants, to
sample and analyze upstream sediment cores from the
Canadian reach of the Columbia River.

    We agree with the district court that the Tribes’ data
collection and analysis efforts were not an unreasonable
means of furthering at least three distinct purposes embraced
by CERCLA.

    First, the expert consultants investigated the presence
and movement of toxic wastes at the Site. We have held that
section 101(23) encompasses such studies into the location
and migration of materials containing hazardous substances.
See Wickland Oil Terminals v. Asarco, Inc., 792 F.2d 887,
22         PAKOOTAS V. TECK COMINCO METALS

889, 892 (9th Cir. 1986) (allowing cost recovery for “testing
. . . of the migration of slag particles” as an action that “may
be necessary to monitor, assess, and evaluate the release or
threat of release of hazardous substances”).

    Second, the Tribes’ experts tested whether the slag and
effluent-contaminated sediment found at the Site leach
contaminants into the environment. Section 101(23) on its
face covers “asses[ing] . . . [the] threat of release of
hazardous substances.” 42 U.S.C. § 9601(23); see also
Wickland, 793 F.2d at 889, 892 (allowing cost recovery for
“conduct[ing] tests to evaluate the hazard posed by the
slag”); Cadillac Fairview/California, Inc. v. Dow Chem.
Co., 840 F.2d 691, 692–93, 695 (9th Cir. 1988) (same).

    And third, the experts traced the origins of the slag and
sediment metals found at the Site. Teck has maintained
before and throughout this litigation that many other sources,
including other smelters, are to blame for the Upper
Columbia River’s pollution. The Tribes commissioned a
study investigating this claim, but the results show that the
wastes match the Trail smelter’s isotopic and geochemical
“fingerprint.”

    Efforts to identify the parties responsible for the disposal
of toxic wastes at a site are likewise recoverable costs of
removal. In Key Tronic Corp. v. United States, 511 U.S. 809
(1994), the Supreme Court considered whether a PRP could
recover fees for work performed by an attorney in searching
for other parties that had used a site for hazardous waste
disposal. Id. at 820. The Court held that “[t]hese kinds of
activities are recoverable costs of response clearly`
distinguishable from litigation expenses.” Id. Indeed,
searches for pollution sources are often conducted by non-
lawyers, such as “engineers, chemists, private investigators,
           PAKOOTAS V. TECK COMINCO METALS                 23

or other professionals”—much like the Tribes’ experts here.
Id.

    Key Tronic appears to have rested its holding on yet
another statutory definition, section 101(25). See id. at 813,
816–20. That provision defines removal and remedial
actions collectively as “response” actions, and then defines
all “response” actions to “include enforcement activities
related thereto.” 42 U.S.C. § 9601(25). The Court in Key
Tronic noted that the search in that case had prompted EPA
to initiate an administrative enforcement action against
another party that had been identified as disposing of wastes
at the site. Id. at 820. The Court also found it significant
that “[t]racking down other responsible solvent polluters
increases the probability that a cleanup will be effective and
get paid for.” Id. Although Key Tronic did not discuss
section 101(23)’s definition of “removal,” the benefit of
making an effective cleanup more likely also falls within the
scope of actions identified by the district court that “may be
necessary to prevent, minimize, or mitigate damage to the
public health or welfare or to the environment.” Similarly,
uncovering evidence that a party is responsible for hazardous
waste puts pressure on that party voluntarily to clean up its
pollution, which would also advance the goals of that
provision. Cf. E.I. DuPont de Nemours & Co. v. United
States, 508 F.3d 126, 135 (3d Cir. 2007) (“Voluntary
cleanups are vital to fulfilling CERCLA’s purpose.”). And
under both provisions, CERCLA’s broad remedial purpose
“supports a liberal interpretation of recoverable costs” to
ensure that polluters pay for the messes they create—
including the difficulties of identifying them in the first
place. United States v. R.W. Meyer, Inc., 889 F.2d 1497,
1503 (6th Cir. 1989) (quoting United States v. Northernaire
Plating Co., 685 F. Supp. 1410, 1419 (W.D. Mich. 1988)).
24         PAKOOTAS V. TECK COMINCO METALS

                              3

    Teck opposes the district court’s conclusion, arguing that
the Tribes’ studies implicitly fall out of the statutory
definitions of “removal” because they are all “litigation-
related.” To be sure, the studies were commissioned after
the Tribes joined this litigation; they were undertaken to help
prove Teck’s liability; and many of them were presented to
the district court in Phase I of trial.

    Teck’s argument relies on a pair of decisions from the
Third Circuit. In Redland Soccer Club, Inc. v. Dep’t of Army
of U.S., 55 F.3d 827 (3d Cir. 1995), the court held that when
evaluating the “necessary” costs of response under section
107(a)(4)(B), it looks to “[t]he heart of the[] definitions of
removal and remedy” and considers whether the costs are
“necessary to the containment and cleanup of hazardous
releases.” Id. at 850 (quoting United States v. Hardage,
982 F.2d 1436, 1448 (10th Cir. 1992)). The court then
applied this rule in Black Horse Lane Assoc., L.P. v. Dow
Chemical Corp., 228 F.3d 275 (3d Cir. 2000), where it held
that “private parties may not recoup litigation-related
expenses in an action to recover response costs pursuant to
section 107(a)(4)(B).” Id. at 294. As Teck points out, the
court noted that the work at issue did not “play[] any role in
the containment and cleanup of the Property,” which meant
it was not “necessary.” Id. at 297.

    We conclude that those out-of-circuit cases are not
persuasive here. The Colville Tribes bring their cost
recovery action as a sovereign under section 107(a)(4)(A),
so they are entitled to “all costs” rather than merely the
“necessary” costs of response. Compare 42 U.S.C.
             PAKOOTAS V. TECK COMINCO METALS                           25

§ 9607(a)(4)(A), with id. § 9607(a)(4)(B). 11 And even if the
latter standard were applicable, we have never interpreted
the term “necessary” as requiring a nexus solely between
recoverable costs and on-site cleanup activities. See Carson
Harbor Vill., Ltd. v. Unocal Corp., 270 F.3d 863, 871 (9th
Cir. 2001) (en banc) (holding that a response action is
necessary if it responds to “an actual and real threat to human
health or the environment”). We instead read CERCLA’s
cost recovery provisions as making no distinction between
cleanup and investigatory costs. Wickland, 792 F.2d at 892.
Neither case cited by Teck speaks to the issue presented—
whether an activity that would otherwise qualify as removal
is disqualified by virtue of having a connection to litigation.
See Black Horse Lane, 228 F.3d at 298 & n.13 (concluding
that “the removal definition . . . exclud[es] the sort of
‘oversight’ costs” sought by plaintiff); Redland Soccer Club,
55 F.3d at 850 (concluding that plaintiffs’ health risk
assessment costs are not “‘response costs’ under any of the[]
definitions” of “removal” and “remedial”).

    Seeing no supportive authorities on point, we decline to
adopt Teck’s reading of “removal” as implicitly excluding
activities that have a connection to litigation. By its terms,
the statute gives no weight to the timing, purpose, or ultimate
use of covered activities. See 42 U.S.C. § 9601(23), (25). A
plaintiff’s ongoing response action may complicate
recovery, but those costs remain recoverable at trial. See
Johnson v. James Langley Operating Co., 226 F.3d 957, 963

    11
       For this reason, we need not decide whether the Tribes’ cost of
fingerprinting wastes at the Site was “necessary” in light of the study
yielding a “duplicative identification” of Teck as a polluter. Syms v. Olin
Corp., 408 F.3d 95, 104 (2d Cir. 2005). But in any case, we cannot fault
the Tribes for paying to learn that Teck disposed of these wastes when
Teck disputed that the wastes could be traced back to the company rather
than to a number of other potential pollution sources.
26         PAKOOTAS V. TECK COMINCO METALS

(8th Cir. 2000) (“[P]laintiffs’ response costs in this case are
not transformed into litigation costs merely by their timing
with respect to their initiation of this action.”); Matter of Bell
Petroleum Servs., Inc., 3 F.3d 889, 908 (5th Cir. 1993)
(“With respect to costs, if any, incurred after the complaint
was filed, prejudgment interest should be assessed on those
costs from the date of the expenditures.”). Further, a
plaintiff’s intent to use the fruits of an investigation in
litigation does not excise that activity from the statutory
definitions of removal. See Johnson, 226 F.3d at 963
(“[T]he motives of the . . . party attempting to recoup
response costs . . . are irrelevant.” (quoting Gen. Elec. Co.
v. Litton Indus. Automation Sys., Inc, 920 F.2d 1415, 1418
(8th Cir. 1990), abrogated on other grounds by Key Tronic
Corp., 511 U.S. 809); cf. Carson Harbor, 270 F.3d at 872
(holding that self-serving “ulterior motive[s]” should be
disregarded when determining whether response costs are
necessary because “[t]o hold otherwise would result in a
disincentive for cleanup”). Many, if not most, CERCLA
plaintiffs study the contamination at a site with an eye to
potential litigation, and it would make little sense to provide
these costs only to parties that are disinclined to file suit.
Finally, recoverable investigation costs do not transform into
unrecoverable costs if the information obtained is later used
to help prove a PRP’s liability. See Vill. of Milford v. K-H
Holding Corp., 390 F.3d 926, 935–36 (6th Cir. 2004)
(holding that the plaintiff could recover from the defendant
the costs of identifying it as a PRP). Indeed, we would turn
Key Tronic’s reasoning on its head if we read that opinion as
making a defendant liable for all PRP search costs except the
cost of identifying that defendant once that evidence is used
in the plaintiff’s case in chief. See 511 U.S. at 820 (lauding
the plaintiff’s investigation for “uncovering the
[defendant’s] disposal of wastes at the site”).
             PAKOOTAS V. TECK COMINCO METALS                           27

    We instead determine whether an activity amounts to
“removal” by comparing the actions taken to the categories
defined by statute. See, e.g., W.R. Grace & Co., 429 F.3d at
1246–47; Hanford Downwinders Coal., Inc. v. Dowdle,
71 F.3d 1469, 1477–79 (9th Cir. 1995); Durfey v. E.I.
DuPont De Nemours & Co., 59 F.3d 121, 124–26 (9th Cir.
1995). The statutory language—not extra-textual factors—
is controlling.

   We conclude that the district court properly awarded the
Colville Tribes all investigation expenses as costs of
removal, even though many of these activities played double
duty supporting both cleanup and litigation efforts. 12

                                    B

   We next consider the district court’s award of the
Colville Tribes’ attorney’s fees.

                                    1

   Shortly after CERCLA was enacted, several district
courts interpreted section 107(a)(4)(A) to mean that the
United States could recover its attorney’s fees for
successfully bringing a response costs action. See, e.g.,
United States v. Ne. Pharm. & Chem. Co. (NEPACCO),
579 F. Supp. 823, 851 (W.D. Mo. 1984), aff’d in part and
     12
        We need not decide whether the Tribe’s removal costs are
“inconsistent with the national contingency plan” because Teck forfeited
this argument by not raising it on appeal. 42 U.S.C. § 9607(a)(4)(A).
Also, we decline to consider Teck’s assertion that the district court “went
beyond the evidence” in calculating the amount of the Tribes’ removal
costs because Teck neither raised this issue in its opening brief, see
United States v. Kelly, 874 F.3d 1037, 1051 n.9 (9th Cir. 2017), nor
provided a sufficient record on which to review this claim, see Fed. R.
App. P. 10(b)(2); In re O’Brien, 312 F.3d 1135, 1137 (9th Cir. 2002).
28         PAKOOTAS V. TECK COMINCO METALS

rev’d in part on other grounds, 810 F.2d 726 (8th Cir. 1986);
United States v. Conservation Chem. Co., 619 F. Supp. 162,
186 (W.D. Mo. 1985); United States v. S.C. Recycling &
Disposal, Inc. (SCRDI), 653 F. Supp. 984, 1009 (D.S.C.
1984), aff’d in part and vacated in part on other grounds sub
nom. United States v. Monsanto Co., 858 F.2d 160 (4th Cir.
1988).

    In early 1985, Congress began considering legislation
that would become the Superfund Amendments and
Reauthorization Act (“SARA”).            During Congress’s
deliberations, EPA submitted information to the hearing
record accounting for the costs of its “enforcement
activities,” a term the agency defined as including “litigation
costs,” “identification of responsible parties” through
“records review” and “field investigations,” and several
other line items. Reauthorization of Superfund: Hearings
Before the Subcomm. on Water Res. of the H. Comm. on Pub.
Works and Transp., 99th Cong. 666–67 (1985) (statement of
Lee M. Thomas, Administrator, Envtl. Protection Agency).
At the time, some of those cases providing the government
its attorney’s fees were still pending on appeal. See
Monsanto, 858 F.2d 160 (4th Cir. 1988); NEPACCO,
810 F.2d 726 (8th Cir. 1986).

    To ensure that these types of expenses could be
recovered, Congress amended section 101(25)’s definition
of “response” to add the following clause: “all such terms
(including the terms ‘removal’ and ‘remedial action’)
include enforcement activities related thereto.” Pub. L. No.
99-499, § 101, 100 Stat. 1613, 1615 (1986) (codified at
42 U.S.C. § 9601(25)). SARA’s Conference Committee
Report summarizes the amendment as “clarif[ying] and
confirm[ing] that such costs are recoverable from
responsible parties, as removal or remedial costs under
          PAKOOTAS V. TECK COMINCO METALS                 29

section 107.” H.R. Conf. Rep. 99-962, at 185 (1986),
reprinted in 1986 U.S.C.C.A.N. 3276, 3278.

     The Supreme Court in Key Tronic considered whether,
in light of SARA’s “enforcement activities” amendment,
“attorney’s fees are ‘necessary costs of response’ within the
meaning of § 107(a)(4)(B).” 511 U.S. at 811. Specifically,
the case concerned whether “a private action under § 107 is
one of the enforcement activities covered by that definition
[such] that fees should therefore be available in private
litigation as well as in government actions.” Id. at 818. The
Court answered this question in the negative. Id. at 818–19.
Given the subject of the appeal, however, the Court offered
“no comment” on whether a government could recover its
attorney’s fees in a “government enforcement action” under
section 107(a)(4)(A). Id. at 817, 819. Dissenting in part,
Justice Scalia, joined by Justices Blackmun and Thomas,
urged that the phrase “enforcement activities” is best
understood “to cover the attorney’s fees incurred by both the
government and private plaintiffs successfully seeking cost
recovery” under either subparagraph. Id. at 824 (Scalia, J.,
dissenting).

    We confronted the question whether section
107(a)(4)(A) allows the federal government to recover its
attorney’s fees in United States v. Chapman, 146 F.3d 1166
(9th Cir. 1998). There we held that CERCLA sufficiently
“evinces an intent” to provide the government its reasonable
attorney’s fees. Id. at 1175–76 (quoting Key Tronic,
511 U.S. at 815). We reasoned that section 107(a)(4)(A)’s
use of the term “all costs” gives the government “very broad
cost recovery rights” standing alone. Id. at 1174 (quoting
NEPACCO, 579 F. Supp. at 850). And we concluded that
Congress need not “incant the magic phrase ‘attorney’s
fees’” where it has “explicitly authorized the recovery of
30          PAKOOTAS V. TECK COMINCO METALS

costs of ‘enforcement activities,’” id. at 1175 (quoting Key
Tronic, 511 U.S. at 823 (Scalia, J., dissenting)), because
“enforcement activities naturally include attorney fees,” id.
(quoting and citing Key Tronic, 511 U.S. at 823 (Scalia, J.,
dissenting)). We also noted that CERCLA generally must
be construed liberally to accomplish its dual goals of
promptly cleaning up hazardous waste sites and making
polluters, rather than society as a whole, pay. See id.
Awarding the government its attorney’s fees furthers these
goals by encouraging responsible parties proactively to clean
up pollution, accept responsibility for cleanup costs, and stop
running up the government’s expenses. Id. at 1175–76.

     We have since observed that Chapman’s holding applies
equally to all of the governmental entities listed in section
107(a)(4)(A). See Fireman’s Fund Ins. Co. v. City of Lodi,
302 F.3d 928, 953 (9th Cir. 2002). By its terms, that
provision makes no distinction between “the United States
Government or a State or an Indian tribe.” 42 U.S.C.
§ 9607(a)(4)(A). Each of these sovereigns is entitled to “all
costs” of a response action, including related “enforcement
activities.” See Reardon v. United States, 947 F.2d 1509,
1514 (1st Cir. 1991) (en banc) (“We cannot give the
definition [in section 101(25)] inconsistent readings within
the statute.”). It follows that section 107(a)(4)(A) “permits
the United States Government or a State or an Indian tribe to
recover all ‘reasonable attorney fees’ ‘attributable to the
litigation as a part of its response costs’ if it is the ‘prevailing
party.’” Fireman’s Fund, 302 F.3d at 953 (quoting
Chapman, 146 F.3d at 1175–76).

                                 2

   Teck contends that Chapman does not apply here
because its holding is tied to the specific facts of that case.
In Chapman, EPA ordered the defendant to remove
           PAKOOTAS V. TECK COMINCO METALS                  31

hazardous substances from the site, and when the defendant
failed to comply, EPA itself initiated a response action.
146 F.3d at 1168–69. EPA then requested repayment for its
response costs, and only after the defendant refused to pay
did the United States bring a response costs action. Id. at
1169. Teck maintains that the Tribes’ response costs action
is distinguishable because it is “not premised on a refused
order or a refusal to fund response costs.”

    We disagree. Neither background fact identified by
Teck was material to the outcome in Chapman. See id. at
1173–76. Litigation may not be necessary if a defendant is
cooperative, but CERCLA does not limit a government’s
recovery of attorney’s fees just to those response costs
actions that are absolutely unavoidable. And we follow the
other circuits that have considered this issue, which have
held that a government’s response costs action amounts to
an “enforcement activit[y]” without so much as mentioning
a requirement that there first be a disobeyed cleanup order or
an unsuccessful repayment negotiation. See United States v.
Dico, Inc., 266 F.3d 864, 878 (8th Cir. 2001); B.F. Goodrich
v. Betkoski, 99 F.3d 505, 528, 530 (2d Cir. 1996), overruled
on other grounds by United States v. Bestfoods, 524 U.S. 51
(1998); see also Reardon, 947 F.2d at 1514 (“[I]f
‘enforcement activities’ in § 9601(25) is interpreted to
exclude the expenses of cost recovery actions, this would
have the effect of denying the government significant
amounts of attorney’s fees—which was certainly not the
intent of Congress.”).

    Because this case is squarely governed by Chapman, we
conclude that the Colville Tribes are entitled to collect their
reasonable attorney’s fees for prevailing in their response
costs action against Teck. See 146 F.3d at 1176; see also
Fireman’s Fund, 302 F.3d at 953.
32         PAKOOTAS V. TECK COMINCO METALS

                              3

    Teck also tries to evade the significance of Chapman by
raising several novel challenges to the district court’s award
of attorney’s fees.

     First, Teck asserts that the Tribes do not have the
requisite “enforcement authority” to recover the costs of any
enforcement activities connected with the Upper Columbia
River Site. Teck reasons that the Tribes lack the response
authority bestowed on the federal government by section
104, 42 U.S.C. § 9604, which Teck claims that EPA can—
but here did not—“delegate” to a state, political subdivision,
or Indian tribe under section 104(d)(1)(A), id.
§ 9604(d)(1)(A). But this provision is irrelevant. Section
104(d)(1)(A) does not address delegation at all; it simply
“authorizes EPA to enter into cooperative agreements or
contracts with a state, political subdivision, or a federally
recognized Indian tribe to carry out [Superfund]-financed
response actions.” 40 C.F.R. § 300.515(a)(1). EPA’s
regulations explain that the agency “use[s] a cooperative
agreement to transfer funds”—not federal authority—“to
those entities to undertake Fund-financed response
activities.” Id. And in any event, the enforcement authority
at issue is whether the Tribes can bring a lawsuit to recover
their response costs. As Teck conceded at oral argument, the
Tribes “clearly can bring a claim for recovery of response
costs” under section 107(a)(4)(A), so they have all the
authority needed to “enforce [this] liability provision.”
Reardon, 947 F.2d at 1512–13; see also Washington State
Dep’t of Transp. v. Washington Nat. Gas Co., Pacificorp,
59 F.3d 793, 801 (9th Cir. 1995) (“States [and tribes] need
not obtain EPA authorization to clean up hazardous waste
sites and recover costs from potentially responsible
parties.”).
           PAKOOTAS V. TECK COMINCO METALS                   33

     Teck next contends that the Tribes cannot recover their
attorney’s fees because this case is not “related to” any
response action at the Site, as required by section 101(25).
In another statutory context, the Supreme Court has
explained that the “ordinary meaning of [the] words ‘related
to’ is a broad one,” meaning “having a connection with or
reference to,” though that breadth “does not mean the sky is
the limit.” Dan’s City Used Cars, Inc. v. Pelkey, 569 U.S.
251, 260 (2013) (alterations omitted) (quoting Rowe v. New
Hampshire Motor Transp. Ass’n, 552 U.S. 364, 370 (2008)).
Adopting that standard here, we conclude that an
enforcement activity falls outside of section 101(25) only if
it has an inadequate connection with an existing or potential
response action at a given site. Although some enforcement
activities can be conducted only after a response action has
begun, some can be conducted beforehand. For instance, a
cash-strapped property owner may wish to locate solvent
polluters to split the tab before incurring response costs, and
EPA may well review and approve a party’s cleanup plans
before any response activities are conducted. See, e.g., Key
Tronic, 511 U.S. at 820 (covering PRP searches); United
States v. E.I. Dupont De Nemours & Co. Inc., 432 F.3d 161,
163, 173 (3d Cir. 2005) (en banc) (covering EPA’s review,
approval, and monitoring of proposed cleanup activities).
Nothing in section 101(25)’s text or the case law interpreting
it requires one activity to come before the other for them to
be related. The Tribes have conducted investigative
activities during the course of this litigation, so the district
court correctly held that this response costs suit is “related
to” a response action at the Site.

   Last, Teck takes issue with the attorney’s fees associated
with the Tribes’ declaratory judgment claim. CERCLA
provides that any court awarding response costs in a section
107(a) action “shall enter a declaratory judgment on liability
34         PAKOOTAS V. TECK COMINCO METALS

for response costs . . . that will be binding on any subsequent
action or actions to recover further response costs.”
42 U.S.C. § 9613(g)(2). As a result, the declaration of
Teck’s liability for future response costs is simply an
additional form of relief that the Tribes obtained through the
same efforts underlying their successful response costs
action. See City of Colton v. Am. Promotional Events, Inc.-
W., 614 F.3d 998, 1007 (9th Cir. 2010). Teck responds that
declaratory relief did not need to be granted to compel Teck
to fund a response action, but this mandatory relief does not
require a showing of necessity. Regardless of whether future
response costs are speculative—or even, as Teck insists,
affirmatively unlikely—CERCLA requires that a successful
plaintiff in a section 107(a) action be awarded both response
costs and declaratory relief. See 42 U.S.C. § 9613(g)(2).

                              4

    Teck also challenges the reasonableness of the attorney’s
fees award under the standard set forth in Hensley v.
Eckerhart, 461 U.S. 424 (1983). Teck contends that if we
agree that the Tribes were not entitled to any costs of
removal, then we should conclude that the district court
misjudged the degree of the Tribes’ success. But we do not
agree with Teck’s premise, so we reject its conclusion. The
district court did not abuse its discretion in finding the
$4.86 million attorney’s fees award to be reasonably
proportionate to the properly awarded $3.39 million for
investigation expenses. See Webb v. Ada Cty., 285 F.3d 829,
837 (9th Cir. 2002). The ratio between attorney’s fees and
the degree of success obtained is also reasonable when one
considers that the Tribes earned a valuable declaratory
judgment, which “confer[s] substantial benefits not
measured by the amount of damages awarded.” Hyde v.
Small, 123 F.3d 583, 584 (7th Cir. 1997); see also In re Dant
             PAKOOTAS V. TECK COMINCO METALS                          35

& Russell, Inc., 951 F.2d 246, 249–50 (9th Cir. 1991) (noting
that CERCLA plaintiffs often “spend some money
responding to an environmental hazard” and then bring a
response cost action to recover their “initial outlays” and to
obtain “a declaration that the responsible party will have
continuing liability for the cost of finishing the job”).

    In sum, we conclude that the district court properly
awarded the Colville Tribes their attorney’s fees, and we do
not disturb the finding that approximately $4.86 million is a
reasonable award in this case.

                                   IV

    The final question presented is whether the district court
erred in granting summary judgment on Teck’s divisibility
defense to joint and several liability. 13

    We review the district court’s grant of summary
judgment de novo, and we may affirm on any basis
supported by the record. Kohler v. Bed Bath & Beyond of
California, LLC, 780 F.3d 1260, 1263 (9th Cir. 2015).
Viewing the evidence in the light most favorable to the
nonmoving party, we must determine whether there is “no
genuine dispute as to any material fact,” Fed. R. Civ. P.
56(a), and whether the district court correctly applied the
relevant substantive law, see Devereaux v. Abbey, 263 F.3d
1070, 1074 (9th Cir. 2001) (en banc).


    13
        Teck’s closing renews its past contentions that this case presents
an extraterritorial application of CERCLA and that Teck cannot be held
liable as an “arranger” under section 107(a)(3), 42 U.S.C. § 9607(a)(3).
We rejected these very arguments more than a decade ago in Pakootas I,
452 F.3d at 1082, and we are bound by that opinion as the law of the
case. See Old Pers. v. Brown, 312 F.3d 1036, 1039 (9th Cir. 2002).
36         PAKOOTAS V. TECK COMINCO METALS

                              A

    The district court granted summary judgment on Teck’s
divisibility defense on the ground that Teck did not have
enough evidence to establish the defense. See Celotex Corp.
v. Catrett, 477 U.S. 317, 322 (1986). In opposing the
motions for summary judgment, Teck relied almost
exclusively on the declaration and report prepared by its
divisibility expert, Dr. Mark Johns.

    Dr. Johns’s report set out to estimate the contributions
from all of the sources of six heavy metals—arsenic,
cadmium, copper, lead, mercury, and zinc—that are found
in the Upper Columbia River and that allegedly originated
from Teck’s smelter. The report began by cataloging many
potential pollution sources dating back to the nineteenth
century. These sources throughout the River’s watershed
include 487 mines, eight mills, six smelters, several
municipal wastewater treatment plants and industrial
operations, urban runoff from the City of Spokane, natural
erosion, and landslides. The materials containing heavy
metals could range from waste rock and tailings to particles
carried by rainwater, mine water seepage, and liquid
effluent; from finely eroded soils to large masses of clay and
rock. The report concluded that Teck’s slag is concentrated
near the U.S.-Canada border and is not found more than
45 miles downriver. By contrast, one smelter dumped slag
into the Upper Columbia River a few miles south of the
border; other smelter slag, mine waste, and soil erosion
could have reached the River at more than ten confluences
with its tributaries; some wastewater treatment plants and
industrial sources discharged liquid effluent to the River
north of the international border; the Spokane River
contributed waste from mining, smelting, wastewater
treatment plants, industrial sources, and urban runoff about
           PAKOOTAS V. TECK COMINCO METALS                   37

100 miles south of the border; and landslides occurred on the
banks of Lake Roosevelt as far as 150 miles downriver.

    The report then identified two methods for apportioning
liability for the River’s pollution, and Dr. Johns’s declaration
identified a third possible method not set forth in his report
but identified at his deposition.

    The primary apportionment method employed a “metals
loading approach.” This approach was based on the premise
that “[t]he harm in this case is the extent of sediment
contamination by hazardous substances released at the Site.”
To calculate the release of hazardous substances from Teck’s
wastes, Dr. Johns credited a study by another one of Teck’s
experts concluding that “no verifiable amount of hazardous
substances were measured leaching from Teck’s slag” and
that no dissolved metals from Teck’s effluent were even
found at the Site. Dr. Johns then expressed his opinion that
because he believed Teck’s wastes are harmless, Teck
should be apportioned 0% of the liability for the Upper
Columbia River’s contamination.

    As an alternative, Dr. Johns conducted a “flux”
apportionment analysis. Unlike the primary apportionment
method, this analysis assumed that the relevant harm is
contamination of the River’s “surface water.” Dr. Johns
evaluated the six heavy metals’ net flux from contaminated
sediment into overlying water. This analysis assumed that
the “diffusion boundary layer to the sediment-water
interface” was limited to the top five centimeters of
sediment. Dr. Johns then estimated the mass of Teck’s slag
present in this top portion of sediment in the northernmost
45 miles of the Site. Using a “theoretical” release rate for
zinc—the only metal “measured to even theoretically release
from slag”—Dr. Johns calculated a maximum daily release
rate for Teck’s slag. He compared this rate against the zinc
38         PAKOOTAS V. TECK COMINCO METALS

flux rate for all remaining sediment in this area, as estimated
by another one of Teck’s experts, and concluded that Teck
should be apportioned a 0.05% share of liability.

    Finally, Dr. Johns testified about a potential mass-based
approach to account for Teck’s share of metals found at the
Upper Columbia River Site. This approach assumed that any
“placement of hazardous substances” into the Site is the
relevant harm. Dr. Johns estimated the mass of metals found
in Teck’s slag and materials from other sources at the Site,
but he ultimately did not use this method to determine Teck’s
portion of liability.

                              B

    The threshold issue on appeal is how to review
divisibility evidence on summary judgment.

                              1

    CERCLA liability is ordinarily joint and several, except
in the rare cases where the environmental harm to a site is
shown to be divisible. United States v. Coeur d’Alenes Co.,
767 F.3d 873, 875 (9th Cir. 2014); see also Martha L. Judy,
Coming Full CERCLA: Why Burlington Northern Is Not the
Sword of Damocles for Joint and Several Liability, 44 New
Eng. L. Rev. 249, 283 (2010) (counting only four decisions
finding divisibility out of 160 cases).

    In Burlington Northern, the Supreme Court confirmed
that “‘[t]he universal starting point for divisibility of harm
analyses in CERCLA cases’ is § 433A of the Restatement
(Second) of Torts.” Burlington N. & Santa Fe Ry. Co. v.
United States, 556 U.S. 599, 614 (2009) (Burlington
Northern II) (quoting United States v. Hercules, Inc., 247
F.3d 706, 717 (8th Cir. 2001)). Under the Restatement,
           PAKOOTAS V. TECK COMINCO METALS                   39

“when two or more persons acting independently cause a
distinct or single harm for which there is a reasonable basis
for division according to the contribution of each, each is
subject to liability only for the portion of the total harm that
he has himself caused.” Id. (quoting United States v. Chem-
Dyne Corp., 572 F. Supp. 802, 810 (S.D. Ohio 1983))
(alteration omitted). “But where two or more persons cause
a single and indivisible harm, each is subject to liability for
the entire harm.” Id. (quoting Chem-Dyne, 572 F. Supp. at
810).

    The divisibility analysis involves two steps. First, the
court considers whether the environmental harm is
theoretically capable of apportionment. See Restatement
(Second) of Torts § 434 cmt. d. This is primarily a question
of law. See United States v. Burlington N. & Santa Fe Ry.
Co., 520 F.3d 918, 942 (9th Cir. 2008) (Burlington Northern
I), rev’d on other grounds, 556 U.S. 599 (2009); United
States v. NCR Corp., 688 F.3d 833, 838 (7th Cir. 2012);
Hercules, 247 F.3d at 718; Bell Petroleum, 3 F.3d at 896.
Underlying this question, however, are certain embedded
factual questions that must necessarily be answered, such as
“what type of pollution is at issue, who contributed to that
pollution, how the pollutant presents itself in the
environment after discharge, and similar questions.” NCR,
688 F.3d at 838. Second, if the harm is theoretically capable
of apportionment, the fact-finder determines whether the
record provides a “reasonable basis” on which to apportion
liability, which is purely a question of fact. Restatement
(Second) of Torts §§ 433A(1)(b), 434 cmt. d; see also
Burlington Northern II, 566 U.S. at 615; NCR, 688 F.3d at
838; Hercules, 247 F.3d at 718; Bell Petroleum, 3 F.3d at
896.
40           PAKOOTAS V. TECK COMINCO METALS

     At both steps, the defendant asserting the divisibility
defense bears the burden of proof. See Restatement
(Second) of Torts § 433B(2); see also Burlington Northern
II, 556 U.S. at 614; NCR, 688 F.3d at 838. This burden is
“substantial” because the divisibility analysis is “intensely
factual.” United States v. Alcan Aluminum Corp., 964 F.2d
252, 269 (3d Cir. 1992) (Alcan-Butler). The necessary
showing requires a “fact-intensive, site-specific”
assessment, PCS Nitrogen Inc. v. Ashley II of Charleston
LLC, 714 F.3d 161, 182 (4th Cir. 2013), generating
“concrete and specific” evidence, Hercules, 247 F.3d at 718.
But that is not to say that the defendant’s proof must rise to
the level of absolute certainty. See Burlington Northern II,
556 U.S. at 618. Rather, the defendant must show by a
preponderance of the evidence—including all logical
inferences, assumptions, and approximations—that there is
a reasonable basis on which to apportion the liability for a
divisible harm. See Restatement (Second) of Torts § 433A
cmt. d; see also, e.g., Hercules, 247 F.3d at 719; Bell
Petroleum, 3 F.3d at 904 n.19.

                                    2

    In the context of a motion for summary judgment,
however, the burdens operate somewhat differently. Teck’s
answer pleaded divisibility as an affirmative defense for
which Teck would bear the burden of proof at trial. 14 To
defeat this affirmative defense on summary judgment, the
Colville Tribes and the State of Washington took on both the
     14
        The Tribes rightly note that “affirmative defense” is something of
a misnomer because divisibility is only a partial defense to liability. But
for the purposes of Federal Rule of Civil Procedure 8(c)(1), even a partial
defense that introduces new matter into a case must be pleaded
affirmatively. 5 Charles Alan Wright & Arthur R. Miller, Federal
Practice and Procedure § 1273 (3d ed. 2018).
           PAKOOTAS V. TECK COMINCO METALS                 41

initial burden of production and the ultimate burden of
persuasion. See Nissan Fire & Marine Ins. Co. v. Fritz Cos.,
Inc., 210 F.3d 1099, 1102 (9th Cir. 2000). Their burden of
production required them to show that Teck did not have
sufficient evidence to prove its defense at trial. See id. If
they carried this burden of production, then Teck had to
produce enough evidence in support of its defense to create
a genuine issue of material fact. See id. at 1103. The Tribes’
and the State’s burden of persuasion on their motions
required them to persuade the court that despite Teck’s
evidence, there was no genuine issue of material fact for
trial. See id. at 1102.

    Here, the Tribes and the State pointed to an absence of
evidence sufficient to support either step of Teck’s
divisibility defense. Teck then had to furnish all evidence
necessary to show both that the harm is theoretically capable
of apportionment and that there is a reasonable basis for
apportioning liability. See, e.g., Chem-Dyne, 572 F. Supp.
at 811. Specifically, Teck had to submit “evidence of the
appropriate dividend and divisor”—the overall harm, and
Teck’s apportioned share. Steve C. Gold, Dis-Jointed?
Several Approaches to Divisibility After Burlington
Northern, 11 Vt. J. Envtl. L. 307, 332 (2009). The Tribes
and the State bore the burden of persuading the court that
this evidence was inadequate.

                              3

    Teck counters that the first question on the motions for
summary judgment is whether the alleged harm could be
divided “under any set of facts,” which would mean Teck
had no burden of production on the overall harm.

   We disagree. Even on a Rule 12(b)(6) motion to
dismiss—that is, before discovery—a non-moving party is
42         PAKOOTAS V. TECK COMINCO METALS

held to more than an “any set of facts” standard. See Bell
Atl. Corp. v. Twombly, 550 U.S. 544, 562–63 (2007). It is
not the court’s job to envision hypothetical scenarios in
which a mix of pollution from multiple sources could
potentially be divisible. Rather than relying on judicial
imagination, Teck was required to “make a showing
sufficient to establish the existence of an element essential
to” its divisibility defense: that the harm is theoretically
capable of division. Celotex, 477 U.S. at 322.

                               4

    Teck then argues that, at most, its burden of production
extended only to addressing the harm from the specific
pollutants that Teck is alleged to have contributed to the Site.
In the operative complaints, the Tribes and the State sought
“the costs of remedial or removal actions, natural resource
damage assessment costs, and natural resource damages that
[plaintiffs] have incurred and will continue to incur at the
Upper Columbia River and Lake Roosevelt where hazardous
substances have come to be located.” The district court read
these pleadings as alleging a harm caused by “all of the
hazardous substances released or threatened to be released
from the Site, from whatever source.” But in Teck’s view,
the harm pleaded is impliedly limited to the six hazardous
substances alleged to have originated from the Trail smelter,
so Teck contends that it can disregard all other types of
pollution found with its wastes at the Site.

     The environmental harm in this case is not so limited.
Section 107(a) imposes strict liability on all PRPs, even if
those persons are in fact not responsible for any pollution at
all. United States v. Atl. Research Corp., 551 U.S. 128, 136
(2007). That is because “Congress has . . . allocated the
burden of disproving causation to the defendant who profited
from the generation and inexpensive disposal of hazardous
            PAKOOTAS V. TECK COMINCO METALS                        43

waste.” Monsanto, 858 F.2d at 170. It certainly is not
always an easy task to determine the entire extent of
contamination at a site. See NCR, 688 F.3d at 841. The
Restatement makes clear, however, that “[a]s between the
proved tortfeasor who has clearly caused some harm, and the
entirely innocent plaintiff, any hardship due to lack of
evidence as to the extent of the harm should fall upon the
former.” Restatement (Second) of Torts § 433B cmt. d.

    In line with CERCLA’s pleading requirements, the
complaints here identified six of Teck’s pollutants just to
establish the company’s liability. The complaints cannot be
fairly read as needlessly narrowing this suit to recovery for
harm caused solely by those pollutants. As a result, Teck
was required to produce evidence showing divisibility of the
entire harm caused by Teck’s wastes combined with all other
River pollution—not just the harm from sources of Teck’s
six metals alone. 15

                                 C

   With the standards of review thus established, we turn to
evaluating the evidence submitted on summary judgment.

                                  1

   The district court primarily granted summary judgment
on the ground that Teck did not have enough evidence to
show that the harm at issue is theoretically capable of
apportionment. The court reasoned that Teck’s evidence

    15
       Teck does not contend, nor does the record reflect, that Teck’s
heavy metals formed an area of pollution that was distinct from areas
with non-metal pollutants. And that would be an argument for
apportioning liability based on distinct harms, not a single divisible
harm. See Restatement (Second) of Torts § 433A(1).
44         PAKOOTAS V. TECK COMINCO METALS

could not establish divisibility because it failed to account
for the entire harm at the Site. Reviewing the parties’
submissions de novo, we agree that there was no genuine
dispute of fact for trial on the question whether the harm to
the Upper Columbia River is theoretically capable of
apportionment.

    At the first step of the divisibility analysis, a court cannot
say whether a harm “is, by nature, too unified for
apportionment” without knowing certain details about the
“nature” of the harm. Burlington Northern I, 520 F.3d at
942, rev’d on other grounds, 556 U.S. 599 (2009); see also
Bell Petroleum, 3 F.3d at 895 (“The nature of the harm is the
key factor in determining whether apportionment is
appropriate.”). As one commentator has explained: “Even if
a party’s waste stream can be separately accounted for, its
effect on the site and on other parties’ wastes at the site must
also be taken into account.” William C. Tucker, All Is
Number: Mathematics, Divisibility and Apportionment
Under Burlington Northern, 22 Fordham Envtl. L. Rev. 311,
316 (2011). That is, “a defendant must take into account a
number of factors relating not just to the contribution of a
particular defendant to the harm, but also to the effect of that
defendant’s waste on the environment.” Id. Those factors
generally include when the pollution was discharged to a
site, where the pollutants are found, how the pollutants are
presented in the environment, and what are the substances’
chemical and physical properties. See NCR, 688 F.3d at 838.
Chief among the relevant properties are “the relative
toxicity, migratory potential, degree of migration, and
synergistic capacities of the hazardous substances at the
site.” United States v. Alcan Aluminum Corp., 990 F.2d 711,
722 (2d Cir. 1993) (Alcan-PAS).
           PAKOOTAS V. TECK COMINCO METALS                 45

     Teck’s divisibility expert identified hundreds of heavy
metal sources that may have contributed to Upper Columbia
River’s pollution throughout its watershed over the course of
more than a century. At Teck’s direction, however, Dr.
Johns expressly curtailed his divisibility analysis to the six
hazardous substances allegedly “attributable to Teck.” But
Teck did not claim that these were the only pollutants found
at the Site.

    Both the Tribes and the State pointed out this deficiency
in their motions for summary judgment. The Tribes cited
evidence of the Site containing the hazardous substances
antimony, beryllium, chromium, nickel, radon, selenium,
thallium, 2,3,7,8-tetrachlorodibenzo-pdioxin, polycyclic
aromatic     hydrocarbons     (“PAHs”),      polychlorinated
biphenyls (“PCBs”), and DDTs. And one of the State’s
experts submitted a declaration stating that EPA was
evaluating the Site for around 199 contaminants of concern,
including PAHs, PCBs, dioxins and furans, and pesticides.
This declaration further showed that sediment samples found
Teck’s metals physically mixed with other hazardous
substances in the northern stretches of the Site. Zinc, for
example, “was detected with other metals like antimony,
arsenic, cadmium, copper, mercury, and lead, and also in
several instances with up to 14 reported organic PAH
chemicals present, as well as less frequently with pesticides
like 2,4-DDT, 4,4 DDE, and 4,4-DDT.”

    Despite this evidence, Teck’s opposition to the motions
for summary judgment continued to rely on Dr. Johns’s
limited analysis. Teck reiterated its assumption that the
Site’s harm was solely traceable to the specific metals that
Teck discharged. While conceding that its slag was “co-
located” with “other slag and tailings,” Teck made no
mention of its pollutants being found alongside non-metal
46         PAKOOTAS V. TECK COMINCO METALS

pollutants. And Teck relied on Dr. Johns’s view that if
Teck’s slag “is not leaching,” as he believed, then “the
location of the slag in sediment is irrelevant to the
apportionment analysis.”

    On these points Teck erred. At the outset, Teck
repeatedly misapprehended the harm here. For the purpose
of apportioning CERCLA liability, the relevant “harm” is
the entirety of contamination at a site that has caused or
foreseeably could cause a party to incur response costs,
suffer natural resource damages, or sustain other types of
damages cognizable under section 107(a)(4). See, e.g.,
Burlington Northern II, 556 U.S. at 618 (suggesting that the
harm is “the overall site contamination requiring
remediation” in a response cost action); NCR, 688 F.3d at
840–41 (“[T]he underlying harm caused [is] the creation of
a hazardous, polluted condition . . . .”); Burlington Northern
I, 520 F.3d at 939 (holding that each share of liability for the
harm is “the contamination traceable to each defendant”),
rev’d on other grounds, 556 U.S. 599 (2009); Chem-Nuclear
Sys., Inc. v. Bush, 292 F.3d 254, 259 (D.C. Cir. 2002)
(“[T]he harm at issue was the release or threatened release
of hazardous substances into groundwater . . . .” (internal
quotation marks omitted)).

    Dr. Johns instead based his apportionment methods on
three inconsistent notions of the Site’s harm: (1) “the extent
of sediment contamination by hazardous substances released
at the Site”; (2) “harm [to] the river,” namely “the surface
water”; and (3) “the placement of hazardous substances” at
the Site. Dr. Johns’s first and second measures of the harm
are incomplete because they look only to the actual releases
of hazardous substances from toxic wastes at the Site,
ignoring the fact that wastes with a “threatened release of
hazardous substances” are likewise contamination that could
           PAKOOTAS V. TECK COMINCO METALS                 47

give rise to response costs. Chem-Nuclear Sys., 292 F.3d at
259 (emphasis added); see also 42 U.S.C. § 9607(a)(4).
Further, the second measure excludes contamination deeper
than five centimeters, even though remedial activities like
dredging would obviously need to excavate these materials
too. Only Dr. Johns’s third apportionment method—the
approach that he sketched briefly in his deposition rather
than outlining in his detailed report—correctly recognized
that the presence of contaminants throughout the Site is the
relevant harm.

    More importantly, all of Dr. Johns’s analysis overlooked
the fact that “the mixing of the wastes raises an issue as to
the divisibility of the harm.” Chem-Dyne, 572 F. Supp. at
811. Mixing of pollutants “is not synonymous with
indivisible harm,” Alcan-PAS, 990 F.2d at 722, but it does
create a rebuttable presumption of such harm, see id.; see
also Monsanto, 858 F.2d at 172; Chem-Dyne, 572 F. Supp.
at 811. The State put this presumption at issue by submitting
evidence of Teck’s metals being found with unrelated
pollutants, yet Teck chose not to address the potential for
synergistic harm from these pollution hotspots.

    Teck responds that the only relevant synergistic effects
are from substances that are chemically commingled, not
just physically interspersed. To that end, Dr. Johns opined
that Teck’s slag cannot chemically interact with other
substances based on his understanding that the slag does not
leach pollutants.

    We are not persuaded. Even if pollutants do not
chemically interact, their physical aggregation can cause
disproportionate harm that is not linearly correlated with the
amount of pollution attributable to each source. In
Monsanto, a key case addressing chemical commingling, the
Fourth Circuit explained: “Common sense counsels that a
48         PAKOOTAS V. TECK COMINCO METALS

million gallons of certain substances could be mixed
together without significant consequences, whereas a few
pints of others improperly mixed could result in disastrous
consequences.” 858 F.2d at 172. Also common sense,
however, is the old adage that sometimes dilution is the
solution to pollution. See, e.g., Carol M. Browner,
Environmental Protection: Meeting the Challenges of the
Twenty-First Century, 25 Harv. Envtl. L. Rev. 329, 331
(2001). For example, “[i]f several defendants independently
pollute a stream, the impurities traceable to each may be
negligible and harmless, but all together may render the
water entirely unfit for use.” W. Keeton et al., Prosser and
Keeton on Law of Torts § 52, p. 354 (5th ed. 1984). The
Second Circuit thus allowed a PRP to be apportioned no
liability if “its pollutants did not contribute more than
background contamination and also cannot concentrate,”
provided that there were no EPA thresholds below those
ambient contaminant levels. Alcan-PAS, 990 F.2d at 722.
And the Third Circuit has held that “the fact that a single
generator’s waste would not in itself justify a response is
irrelevant . . . , as this would permit a generator to escape
liability where the amount of harm it engendered to the
environment was minimal, though it was significant when
added to other generators’ waste.” Alcan-Butler, 964 F.2d
at 264.

    Without knowing more about the accumulation of
Teck’s wastes with unrelated pollutants, with like materials,
and by themselves, a court could not tell whether “their
presence is harmful and the River must be cleaned.” NCR,
688 F.3d at 840. That question is particularly important here
because the most likely remedy for the Site will involve
cleaning up some, but not all, of the contaminants in the 150-
mile long stretch of river.                See 40 C.F.R.
§ 300.430(f)(1)(ii)(D) (requiring EPA to select a cost-
           PAKOOTAS V. TECK COMINCO METALS                   49

effective remedy). More intensive remediation will no doubt
be prioritized where the level of contamination, and the
accompanying danger, is the greatest.

    In conclusion, once the State identified mixing of Teck’s
metals with non-metal pollutants, Teck was required to rebut
the presumption that these pollution hotspots caused greater
harm than the sum of the individual pollutants, each of which
may be so widely dispersed as to be harmless on its own.
Teck did not carry its burden of showing that the harm is
theoretically capable of apportionment by simply
“considering the effects of its waste in isolation from the
other contaminants at a site.” United States v. Alcan
Aluminum Corp., 315 F.3d 179, 187 (2d Cir. 2003) (Alcan-
Consolidated).

    On a related issue concerning the significance of the
buildup of slag, we again reject Teck’s contentions.
Contrary to Dr. Johns’s mistaken assumption, the buildup of
Teck’s slag with other metal-bearing slag or tailings and
even on its own affects the extent of the harm.
Disproportionate harm can occur whether or not the slag
actively leaches pollutants because, as mentioned, the mere
threat of leaching can prompt a response action, and the
accumulation of materials that pose a potential risk makes a
response action more likely. See 42 U.S.C. § 9607(a)(4);
Chem-Nuclear Sys., 292 F.3d at 259. Teck responds that Dr.
Johns’s declaration at least creates a disputed issue of fact on
this point that precludes summary judgment, but in light of
the statutory scheme, no rational trier of fact could believe
this unsupported assumption that the distribution of the slag
is irrelevant. See Matsushita Elec. Indus. Co. v. Zenith
Radio Corp., 475 U.S. 574, 587 (1986). And because Teck’s
slag itself contains a mixture of pollutants, Teck also had to
proffer evidence that the clustering of these pollutants did
50         PAKOOTAS V. TECK COMINCO METALS

not create disproportionate environmental harm.          No
reasonable factfinder could otherwise assume, as Dr. Johns’s
apportionment methods require, that rocks and sand from
landslides and erosion, for example, are candidates for
remediation on par with Teck’s toxic slag. See id.

    Finally, because the divisibility of the Upper Columbia
River’s contamination turns on the specific facts of that
contamination, Teck is also mistaken in arguing that river
pollution is categorically divisible under the Restatement.
See NCR, 688 F.3d at 838. Besides, the Restatement
provides dueling examples of river pollution, and the types
of harm for which section 107(a) provides damages—and
which the Tribes seek—are more akin to the illustration of
an indivisible harm than a divisible harm. Compare
Restatement (Second) of Torts § 433A cmt. i, illus. 15 (river
pollution poisoning animals is indivisible), with id. cmt. d,
illus. 5 (river pollution depriving a riparian owner of the use
of water for industrial purposes is divisible). The Seventh
Circuit reached the same conclusion in NCR, writing: “The
problem here is not that downstream factories were
prevented from using the [river] for some period, but that
wholly apart from water usage, a toxic chemical in the water
causes significant and widespread health problems in both
animals and in humans.” 688 F.3d at 842.

    We hold that Teck did not make a sufficient showing to
establish that liability for environmental harm to the Site is
theoretically capable of apportionment. We fully agree with
the district court that “because [Teck] has failed to account
for all of the harm at the [Upper Columbia River] Site, it
cannot prove that harm is divisible.” And to borrow the apt
words of Alcan-Consolidated, a case involving a defendant-
appellant not carrying its burden of production at trial rather
than on a motion for summary judgment,
           PAKOOTAS V. TECK COMINCO METALS                 51

       appellant did not satisfy its substantial burden
       with respect to divisibility because it failed to
       address the totality of the impact of its waste
       at [the Site]; it ignored the likelihood that the
       cumulative impact of its waste [mixture]
       exceeded the impact of the [mixture’s]
       constituents considered individually, and
       neglected to account for the [mixture’s] . . .
       physical interaction with other hazardous
       substances already at the site.

315 F.3d at 187. Although Teck must only produce evidence
sufficient to create a genuine issue of material fact at the
summary judgment stage, for the reasons stated above, it has
not done so here.

                              2

    As an additional ground for summary judgment, the
Tribes and the State argued that Teck did not have enough
evidence to show a reasonable basis for apportioning
liability. The district court briefly considered this argument
and again sided with the plaintiffs on the ground that Teck
did not show that the chosen proxy—volume of hazardous
substances deposited in the Upper Columbia River—was
proportional to the environmental harm. We agree that the
lack of a reasonable factual basis for apportioning Teck’s
liability provides yet another reason for upholding the
district court’s grant of summary judgment on Teck’s
divisibility defense.

    A defendant asserting a divisibility defense must show
that “there is a reasonable basis for determining the
contribution of each cause to a single harm.” Burlington
Northern II, 556 U.S. at 614 (quoting Restatement (Second)
of Torts § 433A(1)(b)). What is reasonable in one case may
52         PAKOOTAS V. TECK COMINCO METALS

not be in another, so apportionment methods “vary
tremendously depending on the facts and circumstances of
each case.” Hercules, 247 F.3d at 717. Still, the basis for
apportionment may rely on the “simplest of considerations,”
most commonly volumetric, chronological, or geographic
factors. Burlington Northern II, 556 U.S. at 617–18 (quoting
Burlington Northern I, 520 F.3d at 943). The only
requirement is that the record must support a “reasonable
assumption that the respective harm done is proportionate
to” the factor chosen to approximate a party’s responsibility.
Bell Petroleum, 3 F.3d at 896, 903 (quoting Restatement
(Second) of Torts § 433A cmt. d).

    Here, no rational trier of fact could find that Teck has
provided a reasonable basis for apportionment. All three of
Dr. Johns’s apportionment methods are variants of a
volumetric approach in that they are premised on an estimate
of the mass of pollutants at the Site. But as the Fourth Circuit
has noted, “[v]olumetric contributions provide a reasonable
basis for apportioning liability only if it can be reasonably
assumed, or it has been demonstrated, that independent
factors had no substantial effect on the harm to the
environment.” Monsanto, 858 F.2d at 172 n.27. Teck
“presented no evidence, however, showing a relationship
between waste volume . . . and the harm at the site.” Id. at
172.     Instead, the available record undercuts the
reasonableness of Teck’s assuming a proportional
relationship between waste volume alone and the Site’s
contamination, for two main reasons.

    First, as the Tribes point out, Teck’s evidence shows that
geographic factors clearly affected the river’s contamination
throughout this massive site. The Trail smelter’s pollution
entered the Upper Columbia River at the international border
and, according to Dr. Johns, Teck’s slag deposits extend only
           PAKOOTAS V. TECK COMINCO METALS                 53

45 river miles south. But Dr. Johns accounted for the
potential contribution of metals from sources as far as
150 miles downriver, many of which were concentrated at
more than ten different confluences between the River and
its tributaries. Further, conditions varied greatly throughout
the Site; the River is free flowing close to the Canadian
border, causing less sediment to accumulate, but it
eventually slows and forms Lake Roosevelt, preserving
more sediment. As discussed above, these differences in
pollution hotspots will doubtless entail varying remediation
needs and injuries to the natural environment. See Hercules,
247 F.3d at 717. But even if the harm from those hotspots is
capable of division, the fact that contamination strongly
correlates with geography means that this is an independent
factor that substantially affects the environmental harm at
issue. Any proxy for the harm that did not account for
geography thus could not be found reasonable.

    Second, Teck’s evidence also shows that the passage of
time could have a substantial impact on the river’s
contamination given the long time period under
consideration. Dr. Johns accounted for materials deposited
into the Columbia River from the late 1800s through the
present. He testified in his deposition that over time, the
accumulation of new sediment could bury old contaminants,
and in his declaration he said that remediation is not needed
if contaminants are buried beneath at least five centimeters
of sediment. Further, Dr. Johns acknowledged that over
time, slag may slowly release—and thus lose—hazardous
substances to the surrounding environment. The upshot is
that older wastes may present less of a need for cleanup than
more recently disposed wastes. On this record, no
reasonable fact-finder could assume that the time at which
wastes entered the River is irrelevant to determining the
extent of harmful contamination at the Site.
54        PAKOOTAS V. TECK COMINCO METALS

    Other independent factors could also affect the
environmental harm here, but were similarly ignored by
Teck. To take a ready example, some pollutants in the Upper
Columbia River may be more toxic than others, like lead
compared to zinc. And pollutants may have different
migratory potentials based on the media in which they are
deposited, such as glassy slag, powdery tailings, or
suspended particulates. See Monsanto, 858 F.2d at 173 n.26;
see also, e.g., United States v. Manzo, 279 F. Supp. 2d 558,
572–73 (D.N.J. 2003) (rejecting a volumetric apportionment
theory where the defendants did not account for relative
toxicity and migratory potential).

    Absent evidence of how these factors affected the
contamination of the Site, any apportionment would have
been arbitrary. The district court properly “refused to make
an arbitrary apportionment for its own sake.” Burlington
Northern II, 556 U.S. at 614–15 (quoting Restatement
(Second) of Torts § 433A cmt. i). But Teck of course can
always bring a contribution action under section 113(f),
42 U.S.C. § 9613(f), against other pollution sources it
identified, which “mitigates any inequity arising from the
unavailability of apportionment.” PCS Nitrogen, 714 F.3d
at 182.

    In holding that Teck did not carry its burden of
production, we do not mean to suggest that Teck had to rush
the ongoing RI/FS and exhaustively document every
contaminant at the Site to save its divisibility defense from
summary judgment. That was not required. What was
required, however, was that Teck survey the Site,
“comprehensively and persuasively address the effects of its
waste,” and come up with an apportionment method that a
rational trier of fact could find reasonable. Alcan-
Consolidated, 315 F.3d at 187. Teck did not do so here.
          PAKOOTAS V. TECK COMINCO METALS                55

                             V

   For the foregoing reasons, we affirm the district court’s
judgment holding Teck jointly and severally liable for the
Colville Tribes’ costs of response.

   AFFIRMED.
