United States Court of Appeals For the First Circuit
No. 23-1832
CONSERVATION LAW FOUNDATION, INC.,
Plaintiff, Appellant,
v.
ACADEMY EXPRESS, LLC,
Defendant, Appellee,
DPV TRANSPORTATION, INC.; BOSTON CHARTER BUS, LLC; ACADEMY BUS, LLC; WYNN RESORTS, LTD.; WYNN MA, LLC; WYNN RESORTS HOLDINGS, LLC; WYNN AMERICA GROUP, LLC; WYNN RESORTS FINANCE, LLC,
Defendants.
APPEAL FROM THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF MASSACHUSETTS
[Hon. William G. Young, U.S. District Judge]
Before
Gelpí, Howard, and Kayatta, Circuit Judges.
Heather A. Govern, with whom Chelsea E. Kendall, Erica Kyzmir- McKeon, and Conservation Law Foundation were on brief, for appellant. Jared E. Knicley, Elizabeth MeLampy, and Natural Resources Defense Council on brief for Natural Resources Defense Council, amicus curiae. Ian Cogill and Earthjustice on brief for Massachusetts Public Health Association, amicus curiae. Jon C. Cowen, with whom Thomas D. Duquette, Jr. and Donovan Hatem LLP were on brief, for appellee. Linda L. Morkan, Megan E. Baroni, and Robinson & Cole LLP on brief for American Bus Association, Inc., amicus curiae.
February 20, 2025 KAYATTA, Circuit Judge. Environmental group
Conservation Law Foundation (CLF) sued Academy Express, LLC
("Academy"), a transportation company that operates buses up and
down the East Coast. CLF alleged that Academy violated the Clean
Air Act (CAA) by idling its vehicles in excess of state limits in
Massachusetts and Connecticut. Academy moved for summary
judgment, arguing that CLF could not demonstrate associational
standing. The district court agreed and granted Academy's motion.
Conservation L. Found., Inc. v. Acad. Express, LLC, 693 F. Supp.
3d 41, 47 (D. Mass. 2023) [hereinafter, Cons. L. Found.].
CLF now appeals, arguing among other things that the
district court erred by holding that breathing polluted air is not
an injury-in-fact and by requiring tort-like causation to
establish traceability. We agree with CLF that the district court
failed to recognize established forms of cognizable injury and
applied a traceability standard unsupported by case law. That
said, we cannot determine the extent to which CLF can meet its
standing burden because we lack (1) findings on the cognizability
and traceability of injuries asserted by one batch of CLF members
and (2) a determination of whether the record includes the
declarations of additional CLF members and expert witnesses. We
therefore vacate the district court's grant of summary judgment
and remand for further development of the record and application
of the legal standards described in this opinion.
- 3 - I.
For over fifty years, the CAA has helped "to protect and
enhance the quality of the Nation's air resources so as to promote
the public health and welfare and the productive capacity of its
population." 42 U.S.C. § 7401(b)(1). To further this stated
purpose, the CAA divides responsibilities among state and federal
governments. The Environmental Protection Agency (EPA) identifies
air pollutants that "may reasonably be anticipated to endanger
public health or welfare," and promulgates air-quality standards
limiting concentrations of those pollutants. Id. §§ 7408(a),
7409. States, in turn, bear the "primary responsibility" for
ensuring compliance with EPA limits. Id. § 7401(a)(3). To that
end, each state must prepare and submit to the EPA a state
implementation plan (SIP) "provid[ing] for implementation,
maintenance, and enforcement" of EPA pollution limits. Id.
§ 7410(a)(1).
Once the EPA has approved a SIP, it becomes enforceable
as part of the CAA. See Sierra Club v. EPA, 60 F.4th 1008, 1013
(6th Cir. 2023). Private citizens have a role in this enforcement
process by way of a citizen-suit provision, which enables citizen
plaintiffs to seek penalties (payable to the U.S. government) for
each day of an ongoing or repeated SIP violation. 42 U.S.C.
§§ 7604(a)(1), 7413(e)(2). Though the CAA creates a private right
of action, any citizen suing under these provisions must
- 4 - demonstrate constitutional standing, including an injury in
connection with the alleged CAA violation. See Spokeo, Inc. v.
Robins, 578 U.S. 330, 341 (2016) ("Article III standing requires
a concrete injury even in the context of a statutory violation.").
As part of their approved SIPs, Massachusetts and
Connecticut each limit vehicle idling. Massachusetts prohibits
any person from running "the engine of a motor vehicle while said
vehicle is stopped for a foreseeable period of time in excess of
five minutes," 310 Mass. Code Regs. 7.11(1)(b) (2025), and
Connecticut prohibits unnecessary idling for more than three
minutes, Conn. Agencies Regs. § 22a-174-18(b)(3)(C) (2025).
Seeking declaratory and injunctive relief and civil
penalties, CLF sued Academy1 for alleged repeated violations of
the Massachusetts and Connecticut idling limits. Specifically,
CLF claimed that it deployed investigators on twenty-six days
between September 2019 and September 2020, and that on every one
of those days, its investigators observed at least one Academy
1On January 8, 2020, CLF simultaneously filed two lawsuits, one against Academy and its affiliate, Academy Bus, LLC ("Academy Bus"), and the other against Academy, Academy Bus, two other bus companies, and a group of hotel/casino companies with which all the bus companies allegedly worked. CLF voluntarily dismissed its claims against Academy Bus and the hotel/casino companies in 2020. The district court consolidated the two cases in August 2023 and entered summary judgment for the bus companies the following month. CLF appealed as to all three bus companies, two of which later settled with CLF through this court's Case Appeals Management Plan. As a result, Academy is the sole remaining appellee.
- 5 - idling violation, totaling 109 violations across five
Massachusetts locations and thirty idling violations at one
Connecticut lot.2 From these observations, CLF alleged that
Academy had a practice of illegal idling and consequently "that
additional information from other sources not yet publicly
available w[ould] reveal additional violations." CLF further
asserted that its members "include individuals who live and
recreate near" the Massachusetts and Connecticut bus stops and
lots, "where vehicles owned, operated and/or managed by Academy
idle in excess" of state limits. Academy's buses, CLF claimed,
include diesel-fuel vehicles, which "emit diesel fuel exhaust
including fine particulates, nitrogen oxides ('NOx'), sulfur
dioxide ('SO2'), benzene, formaldehyde, and forty other kinds of
toxic air contaminants." As a result, CLF alleged, Academy
"causes, suffers, allows, and/or permits the emission of" those
pollutants into the air when its buses idle.
CLF alleged injuries on behalf of its members,
including: (1) "breath[ing] the emissions and air pollutants"
emitted by Academy's buses as they idle in excess of applicable
limits; (2) adverse physical reactions related to breathing the
2 The Massachusetts locations were the Newton Go bus stop (also known as the Riverside Green Line station), Pond Street lot (also known as the Braintree lot), Harry Agganis Way shuttle stop, Cambridge Go bus stop, and Wellington station. The Connecticut lot was the Bridgeport lot. CLF alleges three additional violations at the Bridgeport lot on November 24, 2021.
- 6 - air pollutants; and (3) "reasonabl[e] concern[]" about inhaling
pollutants and that such pollutants may adversely affect their
health. Discovery commenced, and CLF submitted affidavits and
deposition testimony of its members aimed at connecting their
alleged injuries to the six locations where CLF observed excessive
idling. To that end, CLF timely identified ten "standing"
witnesses. Shortly after the close of fact discovery, Academy
moved for summary judgment, asserting that CLF could not establish
standing. CLF opposed, and once the parties had briefed the
motions, the district court heard oral argument on April 14, 2021.
At this point, the record becomes less than clear. Two
years elapsed following the oral argument on Academy's summary
judgment motion. During this period, "CLF periodically
supplemented its disclosures," adducing a total of ten additional
standing witnesses. CLF appears to have disclosed six of these
witnesses via supplemental disclosures under Federal Rule of Civil
Procedure 26. It included the declarations of the four other
witnesses as exhibits attached to two motions seeking to file
supplemental briefs. Academy moved to preclude the six witnesses
whom CLF disclosed via Rule 26 supplemental disclosures and
opposed both of CLF's motions to file supplemental briefs. The
district court does not appear to have ruled on Academy's motions
to preclude. It did, however, grant both of CLF's motions to file
- 7 - supplemental briefs, albeit without explicitly addressing the
declarations that CLF had attached to those motions.
In addition to disclosing additional standing witnesses
following the close of fact discovery, CLF also disclosed three
expert witnesses. The organization apparently sent reports by its
three experts to Academy's counsel on May 28, 2021 -- the court-
ordered expert-disclosure deadline. It also appears to have
attached two of those expert reports as exhibits to a motion
related to a separate discovery dispute between the two parties.
On November 12, 2021, Academy moved to exclude the testimony of
all three CLF expert witnesses. CLF opposed that motion, which
the district court stayed on June 23, 2023. Just five days later,
the case was reassigned to a different judge. It seems that
neither judge ever ruled definitively on Academy's motion to
exclude the testimony of CLF's expert witnesses.
Notwithstanding these two loose ends concerning the
scope of the record, the district court granted Academy's motion
for summary judgment on September 14, 2023, holding that CLF lacked
associational standing. Cons. L. Found., 693 F. Supp. 3d at 44–
45. In so holding, the court expressly considered only CLF's first
ten standing witnesses. See id. at 45. It additionally opined
"that the expert testimony offered by [CLF] would not affect" the
standing analysis, but it did not formally rule on whether that
testimony fell within the record. Id. at 52.
- 8 - Still considering only CLF's first ten witnesses, the
district court held that two -- Tommaso Wagner and Sabrina
Morelli -- had alleged injuries-in-fact. See id. at 50. Wagner
had testified that he would run more often if the air quality
around his home improved, and Morelli had testified that she too
would run more if Academy "stopped idling its buses and there was
consequently less air pollution" around two locations near which
she occasionally ran. While the other eight standing witnesses
had alleged harms including breathing polluted air, fear of ill
health effects from pollution, and diminished enjoyment of outdoor
activities, the district court held that these concerns did not
rise to the level of injuries-in-fact. See id. In so holding, it
reasoned that (1) "[t]he smell of exhaust alone appears
insufficient to establish an injury"; (2) "concern regarding
adverse health effects" must be "linked to specific medical
conditions" to establish injury; and (3) recreational harms were
"purely hypothetical" where members had "not modified their
behavior due to the exhaust levels in their communities." Id.
Turning to the cause of Wagner's and Morelli's asserted
injuries, the district court held that the connection between the
members' reduced recreation and Academy's excess idling was "just
too attenuated to satisfy" standing's traceability requirement.
Id. at 52. "In an urban environment," it explained, "a span of a
mile or two contains numerous vehicles and bus stops," meaning
- 9 - that "the injuries alleged cannot be conclusively linked to the
excessive idling by the Defendants." Id. Having thus found that
Wagner's and Morelli's asserted injuries were not traceable to
Academy's excessive idling, the district court did not reach the
standing inquiry's redressability prong. Id. at 48 n.3.
CLF timely appealed, arguing that the district court
erred both factually and legally. "Factually," CLF asserts that
"the district court simply did not address significant portions of
the factual record that show that CLF satisfies" Article III
standing. "Legally," it contends, "the district court appears to
have viewed the 'injury-in-fact' and 'fair traceability' tests
through the lens of tort law, imposing on them higher barriers
than the Constitution or the relevant precedents permit."
II.
We consider first a threshold matter raised by the
parties: When must CLF's standing witnesses have joined CLF such
that it can invoke standing on their behalf? Without any on-point
case law to support its stance, Academy maintains that "CLF cannot
premise its standing on individuals who were not members of the
organization at the time . . . they allegedly suffered the harm."
CLF, by contrast, insists that "[a]ssociational standing requires
only that CLF have at least one member [with standing] at the time
the latest complaint was filed" -- i.e., October 29, 2020.
- 10 - We agree with CLF in part: Its members upon whose
standing it relies need not have joined the organization before
Academy allegedly harmed them. On the other hand, having only one
member with standing does not necessarily establish standing for
all claims. "[S]tanding is not dispensed in gross; rather,
plaintiffs must demonstrate standing for each claim that they press
and for each form of relief that they seek (for example, injunctive
relief and damages)." TransUnion LLC v. Ramirez, 594 U.S. 413,
431 (2021).
When assessing associational standing, the Supreme Court
has not focused on membership at the time of the alleged harm.
Rather, the Court has made clear that standing "must exist at the
commencement of the litigation" and "must continue throughout its
existence." Friends of the Earth, Inc. v. Laidlaw Env't Servs.
(TOC), Inc., 528 U.S. 167, 189 (2000) (citation omitted). It has
likewise noted that "when a plaintiff files a complaint in federal
court and then voluntarily amends the complaint, courts look to
the amended complaint to determine jurisdiction." Rockwell Int'l
Corp. v. United States, 549 U.S. 457, 473–74 (2007). Here, then,
we look to the amended complaint filed on October 29, 2020, to
determine jurisdiction: CLF must show that it -- through its
members -- had standing as of that date to bring its claims for
each of its six asserted locations.
- 11 - Nine of the original ten standing witnesses had joined
CLF by October 29, 2020.3 For ease of reference, we refer to those
nine individuals as the "Nine Members." And for five of the six
locations,4 at least one of the Nine Members asserts standing to
complain about Academy's excessive idling.
III.
To sue on behalf of its Nine Members, CLF must also show
that (1) "its members would otherwise have standing to sue in their
own right"; (2) "the interests it seeks to protect are germane to
the organization's purpose"; and (3) "neither the claim asserted
nor the relief requested requires the participation of individual
members in the lawsuit." Hunt v. Wash. State Apple Advert. Comm'n,
432 U.S. 333, 343 (1977). Academy does not contest -- and the
record demonstrates -- that CLF meets the second and third elements
of this test. The parties thus train their attention on whether
any of the Nine Members have standing to sue Academy.
"The existence of standing is a legal question, which we
review de novo." Kerin v. Titeflex Corp., 770 F.3d 978, 981 (1st
Cir. 2014). "In response to a summary judgment motion," the party
invoking federal jurisdiction cannot rely on "'mere allegations,'
but must 'set forth' by affidavit or other evidence 'specific
3 Only Kathleen Becker had not. 4 Those five locations are the Bridgeport lot, Newton Go bus stop, Cambridge Go bus stop, Harry Agganis Way shuttle stop, and Wellington station.
- 12 - facts,'" supporting the elements of standing, "which for purposes
of the summary judgment motion will be taken to be true." Lujan
v. Defs. of Wildlife, 504 U.S. 555, 561 (1992) (quoting Fed. R.
Civ. P. 56(e)).
To have individual standing to sue, a litigant "must
have (1) suffered an injury in fact, (2) that is fairly traceable
to the challenged conduct of the defendant, and (3) that is likely
to be redressed by a favorable judicial decision." Spokeo, 578
U.S. at 338. These three requirements aim to ensure that a
plaintiff has "such a personal stake in the outcome of the
controversy as to warrant . . . federal-court jurisdiction."
Summers v. Earth Island Inst., 555 U.S. 488, 493 (2009) (quotation
mark omitted) (quoting Warth v. Seldin, 422 U.S. 490, 498 (1975)).
We address these three requirements in turn.
A.
To qualify as an injury-in-fact, a complained-of harm
must be "concrete and particularized" and "actual or imminent."5
Laidlaw, 528 U.S. at 180. An injury is concrete when it is "real,
and not abstract," though it need not be "tangible," Spokeo, 578
U.S. at 340 (quotation marks and citation omitted), or large, see
Adams v. Watson, 10 F.3d 915, 918 (1st Cir. 1993) ("[A]n
5 Because Academy does not meaningfully argue that CLF has failed to satisfy the "actual or imminent" requirement -- and because CLF has in fact satisfied it -- we focus here and elsewhere in this opinion on the "concrete and particularized" requirement.
- 13 - identifiable trifle is enough . . . ." (quoting United States v.
Students Challenging Regul. Agency Procs. (SCRAP), 412 U.S. 669,
689 n.14 (1973))). It is particularized if it "affect[s] the
plaintiff in a personal and individual way." Lujan, 504 U.S. at
560 n.1. Finally, when assessing standing, a court should consider
"whether the alleged injury to the plaintiff has a 'close
relationship' to a harm 'traditionally' recognized as providing a
basis for a lawsuit in American courts." TransUnion, 594 U.S. at
424 (quoting Spokeo, 578 U.S. at 341).
CLF alleges that its members suffer the following harms
from Academy's CAA violations: "breath[ing] the emissions and air
pollutants that Defendant causes"; "see[ing] air pollution coming
from" Academy's vehicles; trouble breathing and respiratory
symptoms near where Academy's vehicles have been seen idling; and
"concern[]" that Academy's emissions "have harmed, continue to
harm and threaten, and will harm and threaten their health, well-
being, quality of life, and enjoyment, as well as that of their
families." Some CLF members also recount diminished recreational
enjoyment.
The district court held that most of these alleged
injuries are not cognizable. See Cons. L. Found., 693 F. Supp. 3d
at 50. The court was "not satisfied" that "simply breathing and
smelling polluted air is an injury" without "associated physical
side effects, recreational or aesthetic harm, or well-grounded
- 14 - fear of health effects." Id. at 49. And even where CLF members
concerned about adverse health effects note that they are
especially predisposed to respiratory illness,6 the district court
treated their concerns as not "credible and concrete," because the
members have not testified that their health issues have worsened
and because it is "unclear whether these fears of health effects
from exhaust pollution are reasonable." Id. at 49–50. It likewise
held that the CLF members' asserted recreational harms are not
cognizable if the members "have not modified their behavior due to
the exhaust levels in their communities." Id. at 50. As a result,
it held that only members Wagner and Morelli assert "true
recreational harms" through their testimony that they would run
more frequently if the air around Academy's bus stops and lots
were less polluted. Id. For the reasons that follow, we disagree
with the district court's constrained view of cognizable injury.
1.
First, we hold that "breathing and smelling polluted
air" are both injuries-in-fact, even when unaccompanied by
additional associated harms. To reach this conclusion, we follow
the Supreme Court's directive to look to "harm[s] traditionally
recognized as providing" bases for lawsuits "in American courts"
6For example, CLF member Robert Kendall testifies that he has "a lot of problems with allergies and with sleep apnea" and "worr[ies] that air pollutants could be making these respiratory issues worse."
- 15 - to gauge whether an asserted harm is cognizable. TransUnion, 594
U.S. at 417. "The most obvious" of these historically cognizable
harms "are traditional tangible harms, such as physical harms."
Id. at 425.
Smelling unpleasant odors and breathing polluted air
undoubtedly fall into this category. At common law, courts
recognized as public nuisances "a large, miscellaneous and
diversified" range of offenses "interfer[ing] with the interests
of the community at large -- interests that were recognized as
rights of the general public entitled to protection." Restatement
(Second) of Torts § 821B cmt. b (Am. L. Inst. 1979). These "public
nuisances included interference with the public health, . . .
[and] with the public comfort, as in the case of widely
disseminated bad odors, dust and smoke." Id.; see also, e.g.,
Commonwealth v. Kidder, 107 Mass. 188, 192 (1871) ("A nuisance at
common law may consist . . . in the carrying on of any trade or
business in such a manner as to emit offensive odors and
stenches . . . ."); People v. Detroit White Lead Works, 46 N.W.
735, 735–37 (Mich. 1890) ("[T]he creation and emission of
unwholesome, offensive, and nauseating odors, smells, vapors, and
smoke . . . clearly [constitute] a nuisance . . . .").
In short, breathing polluted air is "traditionally
recognized as providing a basis for a lawsuit in American courts."
TransUnion, 594 U.S. at 417. And given this longstanding
- 16 - historical practice, we join several of our sister circuits in
holding that air-pollutant exposure is an injury-in-fact,
regardless of whether additional harms attend that exposure. See
Sierra Club v. Franklin Cnty. Power of Ill., LLC, 546 F.3d 918,
925 (7th Cir. 2008) (explaining that "likely exposure to
pollutants" satisfies the injury-in-fact requirement (cleaned
up)); LaFleur v. Whitman, 300 F.3d 256, 271 (2d Cir. 2002)
(providing that "[a]ctual exposure to increased levels of" a
pollutant is an injury-in-fact, even if the levels still fall
within federal standards); Texans United for a Safe Econ. Educ.
Fund v. Crown Cent. Petroleum Corp., 207 F.3d 789, 792 (5th Cir.
2000) (favorably citing precedent holding that "breathing and
smelling polluted air is sufficient to demonstrate injury-in-fact
and thus confer standing under the CAA"); Nat. Res. Def. Council,
Inc. v. EPA, 507 F.2d 905, 910 (9th Cir. 1974) ("[An individual]
will suffer injury if compelled to breathe air less pure than that
mandated by the Clean Air Act.").
2.
We also disagree with the district court's conclusion
that "[t]he only true recreational harms" asserted by CLF members
are those that involve members changing their behavior in response
to exhaust levels. Cons. L. Found., 693 F. Supp. 3d at 50. For
example, the district court found no cognizable harm alleged by
CLF member Thomas Cahill, id., who avers that he might stop using
- 17 - a bikeway because Academy's nearby idling "negatively impacts
[his] enjoyment of and ability to recreate on the bikeway." The
district court described Cahill as asserting "purely hypothetical
recreational harms" since Cahill "continues to make regular use of
the trail." Id.
This stringent standard for recreational harm
contravenes precedent. The Supreme Court has long "held that
environmental plaintiffs adequately allege injury in fact when
they aver that they use the affected area and are persons 'for
whom the aesthetic and recreational values of the area will be
lessened' by the challenged activity." Laidlaw, 528 U.S. at 183
(quoting Sierra Club v. Morton, 405 U.S. 727, 735 (1972)). It has
articulated no requirement that an environmental plaintiff must
abandon a polluted area in order to have suffered an injury-in-
fact. Nor has this court. Indeed, we recently recognized that
individuals who testified that they lived near a proposed disposal
facility, "use[d] that area for recreation," and feared "that the
disposal facility [would] negatively impact their use and
enjoyment of the area" had "plainly" alleged injuries-in-fact.
Housatonic River Initiative v. EPA, New England Region, 75 F.4th
248, 265 (1st Cir. 2023). While avoiding certain activities
because of pollution -- as alleged by Wagner and
Morelli -- certainly constitutes a cognizable recreational injury,
so too is continuing those activities but enjoying them less.
- 18 - 3.
We also cannot agree with the district court's
conclusion that a reasonable fear of health effects from pollution
is not on its own a cognizable injury. The district court implied
that to constitute injury-in-fact, such concerns must be "tied to
specific medical conditions" or accompanied by "more tangible
harms." Cons. L. Found., 693 F. Supp. 3d at 49. But that is not
the test. Rather, Laidlaw frames the inquiry as hinging on "the
reasonableness of the fear that led the affiants" in the case to
avoid the polluted waterway at issue. 528 U.S. at 184 (cleaned
up); see also Me. People's All. & Nat. Res. Def. Council v.
Mallinckrodt, Inc., 471 F.3d 277, 284 (1st Cir. 2006) ("[A]n
individual's decision to deny herself aesthetic or recreational
pleasures based on concern about pollution will constitute a
cognizable injury only when the concern is premised upon a
realistic threat." (citing Laidlaw, 528 U.S. at 184; City of Los
Angeles v. Lyons, 461 U.S. 95, 107 n.8 (1983))).
In holding that the affiants' fears were indeed
reasonable, Laidlaw explained that there was "nothing 'improbable'
about the proposition that a company's continuous and pervasive
illegal discharges of pollutants into a river would" harm
recreational users of that river. 528 U.S. at 184. For purposes
of determining injury-in-fact here, similar reasoning applies.
Recall that the CAA directs the EPA to identify pollutants whose
- 19 - emissions "may reasonably be anticipated to endanger public health
or welfare" and for those pollutants set air quality standards
"requisite to protect the public health." 42 U.S.C.
§§ 7408(a)(1), 7409. In implementing those standards,
Massachusetts and Connecticut set limits on vehicle idling. 310
Mass. Code Regs. 7.11(1)(b) (2025); Conn. Agencies Regs. § 22a-
174-18(b)(3)(C) (2025).
As in Laidlaw and Mallinckrodt, then, it is entirely
reasonable for CLF members to believe that repeated and continuing
CAA violations pose a realistic threat to those who are exposed to
the excessive fumes. We thus join several other courts of appeals
in holding that these concerns alone can constitute injuries-in-
fact. See, e.g., Clean Wis. v. EPA, 964 F.3d 1145, 1156 (D.C.
Cir. 2020) ("Adverse health effects . . . constitute Article III
injuries, even if a petitioner merely asserts realistic health
concerns instead of providing medical evidence."); N.Y. Pub. Int.
Rsch. Grp. v. Whitman, 321 F.3d 316, 325 (2d Cir. 2003) ("We are
persuaded that [Appellant's] members' allegations about the health
effects of air pollution and of uncertainty as to whether the EPA's
actions expose them to excess air pollution are sufficient to
establish injury-in-fact . . . ."); see also Env't Tex. Citizen
Lobby, Inc. v. ExxonMobil Corp., 968 F.3d 357, 368 (5th Cir. 2020)
(describing the fact that affiants "feared for their health" as
"an Article III injury"), vacated on other grounds, 61 F.4th 1012,
- 20 - 1012–13 (5th Cir. 2023) (mem.) (per curiam), and decided en banc,
123 F.4th 309 (5th Cir. 2024) (mem.) (per curiam).
In sum, we hold that the district court erred by imposing
new requirements for establishing injury-in-fact that are
unsupported by case law. On remand, the district court should
apply the proper standards, as described above, to determine which
CLF members -- in addition to Wagner and Morelli -- have alleged
injuries-in-fact.
B.
We now turn to the requirement that any injury-in-fact
be "fairly traceable to the challenged conduct of the defendant."
Spokeo, 578 U.S. at 338. The Supreme Court has explained that the
fairly traceable standard requires "a causal connection between
the injury and the conduct complained of." Lujan, 504 U.S. at
560. However, the standard does not require a tort-like showing
of proximate causation. See Lexmark Int'l, Inc. v. Static Control
Components, Inc., 572 U.S. 118, 134 n.6 (2014) ("Proximate
causation is not a requirement of Article III standing, which
requires only that the plaintiff's injury be fairly traceable to
the defendant's conduct.").
A plaintiff can satisfy traceability by showing "that
the defendant's conduct is one among multiple causes" of the
alleged injury. 13A Charles Alan Wright, Arthur R. Miller & Edward
H. Cooper, Federal Practice & Procedure § 3531.5 (3d ed. 2008).
- 21 - Here, multiple parties, in addition to Academy, each allegedly
contribute distinct, not mutually dependent, portions of CLF
members' asserted injuries. Traceability in such a case exists
where the defendant's alleged conduct, while arguably not
responsible for the entire asserted injury, nevertheless causes a
"concrete and particularized," Laidlaw, 528 U.S. at 180, portion
of that injury. See, e.g., Nat. Res. Def. Council, Inc. v. Texaco
Refining & Mktg., Inc., 2 F.3d 493, 505 (3d Cir. 1993) (finding
standing where many sources contributed to river pollution and the
defendant's unlawful discharge caused or contributed to the kinds
of injuries alleged); Sierra Club, Lone Star Chapter v. Cedar Point
Oil Co., 73 F.3d 546, 558 (5th Cir. 1996) ("Given the number of
entities discharging chemicals into Galveston Bay, it would be
virtually impossible . . . to trace [the plaintiff's] injuries to
Cedar Point's discharge in particular. Rather, it is
sufficient . . . to show that Cedar Point's discharge . . .
contributes to [the plaintiff's asserted harm]."); Texans United,
207 F.3d at 793 (finding standing in air-pollution case even where
an injunction against the defendant would "not reduce pollution
from other sources not before th[e c]ourt").
In applying this standard to a case with multiple alleged
contributors to a cumulative harm, a court may find it helpful to
engage in a counterfactual inquiry, asking whether the defendant's
alleged conduct would "have been a factual cause [of a concrete
- 22 - and particularized portion of the injury] if the other competing
cause[s] had not been operating." Restatement (Third) of Torts:
Liability for Physical & Emotional Harm § 27 cmt. a (Am. L. Inst.
2010); see also Walters v. Fast AC, LLC, 60 F.4th 642, 651 (11th
Cir. 2023) (importing this standard into the Article III
traceability analysis); Fischer v. Governor of N.J., 842 F. App'x
741, 755–56 (3d Cir. 2021) (Phipps, J., concurring in part and
concurring in the judgment) (same).7
Here, the district court held that the "connections
between the members' injuries and the Bus Companies' [unlawful]
conduct are just too attenuated to satisfy" Article III's
traceability requirement. Cons. L. Found., 693 F. Supp. 3d at 52.
"In an urban environment," it reasoned, "a span of a mile or two
contains numerous vehicles and bus stops. In such an environment,
the injuries alleged cannot be conclusively linked to the excessive
idling by the Defendants." Id. But the existence of other
potentially culpable vehicles does not eliminate traceability.
CLF need only show that Academy's unlawful conduct, standing alone,
causes a "concrete and particularized," Laidlaw, 528 U.S. at 180,
7We need not decide what test would apply where the complained-of conduct would not, by itself, cause a "concrete and particularized," Laidlaw, 528 U.S. at 180, portion of the asserted injury. Such cases, including those involving indivisible harm, see Restatement (Third) of Torts: Apportionment of Liability § A18 (Am. L. Inst. 2000), pose unique traceability questions not present here.
- 23 - portion of CLF members' asserted injuries. And CLF need not show
a "conclusive[] link[]," Cons. L. Found., 693 F. Supp. 3d at 52,
to prove that causal connection.
In lieu of requiring a conclusive link, we hold that a
showing of geographic proximity can satisfy traceability in this
type of case. Several of our sister circuits have adopted
analogous approaches in the context of alleged CAA violations.
See, e.g., LaFleur, 300 F.3d at 270 (focusing the traceability
inquiry on geographic proximity to the air-pollution source); Utah
Physicians for a Healthy Env't v. Diesel Power Gear, LLC, 21 F.4th
1229, 1248 (10th Cir. 2021) ("If the [defendants'] vehicle was
driven, however little, in the Salt Lake City area, [the plaintiff
organization] has established that its members' injuries from
excessive pollution can be fairly traced to the CAA
violation . . . ."); Sierra Club v. Tenn. Valley Auth., 430 F.3d
1337, 1345 (11th Cir. 2005) (similar to LaFleur).8 Thus, upon a
requisite showing of geographic proximity, a CAA plaintiff can
satisfy traceability -- even if "other sources" may have
"contributed to" the complained-of pollution. Utah Physicians, 21
F.4th at 1244 (citation omitted).
8A Fifth Circuit panel held similarly in Environment Texas Citizen Lobby, 968 F.3d at 370, but the en banc court vacated that decision, 61 F.4th at 1012–13, deadlocked, and summarily affirmed the district court's judgment (which found standing) without substantive comment, 123 F.4th at 310–11.
- 24 - But what is that geographic proximity? Surely a
plaintiff in Providence, Rhode Island, could not claim injury from
an idling bus in Portland, Maine; indeed, "appellate courts have
recognized that a plaintiff may lack standing to challenge actions
by a too-distant polluter." Id. at 1246. And equally surely, a
plaintiff just a few yards from the tailpipe of an unlawfully
idling bus satisfies traceability for an injury like smelling that
bus's fumes, even if other buses also idle nearby. See Friends of
the Earth, Inc. v. Gaston Copper Recycling Corp., 204 F.3d 149,
162 (4th Cir. 2000) (providing that plaintiffs can satisfy
traceability merely by showing that they "sit[] squarely in the
discharge zone of a polluting facility").
CLF urges us to hold that that the requisite geographic
vicinity is "under a few miles," noting that some courts "have
taken judicial notice of the fact that air pollution travels."
But without expert testimony, how are we to know how far and in
what concentration it travels? And with what effects? CLF
suggests that these exactitudes are beside the point, gesturing to
a standard initially deployed in a Clean Water Act case: "Rather
than pinpointing the origins of particular molecules, a plaintiff
must merely show that a defendant discharges a pollutant that
causes or contributes to the kinds of injuries alleged in the
specific geographic area of concern." Id. at 161 (quotation marks
and citation omitted). This might arguably be enough to establish
- 25 - traceability in the context of water pollution, where a toxin
entering a river at point A reliably reaches a point B downstream.
But, as Academy points out, "air is different than water," and the
traceability analysis must be different as well.
Common sense tells us that traceability may be simple at
very close range. For example, some CLF members regularly use the
same transportation centers where Academy's buses idle often.
Another spends "significant amounts of time" on a bikeway "directly
by" one of the stops. While these individuals seem to be "squarely
in the discharge zone" such that expert analysis may not be
necessary to establish traceability, see Gaston Copper Recycling,
204 F.3d at 162, we leave it to the district court to engage in
the requisite factfinding and apply the proper legal standards to
these facts. As for CLF members whose testimony does not place
them at or near the commuter stations, we think it likely that CLF
can only establish traceability by adducing expert testimony
explaining how the pollution travels to, and ultimately affects,
those members. Again, however, we leave it to the district court
to adjudicate these issues in the first instance.
Finally, Academy argues that CLF must place its members
in the geographic vicinity of the bus stops and lots during the
"isolated instances of bus idling alleged in the complaints." But
CLF has not merely alleged injuries stemming from "isolated
instances." Instead, CLF argues that the pattern of violations
- 26 - that its investigators observed across twenty-six days -- at least
one violation (and often more) per day of
observation -- demonstrates Academy's "routine practice of
excessive idling each and every day that its buses are in
operation." Notably, Academy does not meaningfully dispute that
CLF's complaint is best read as alleging a pattern or practice of
unlawful idling, rather than a series of isolated incidents.
This alleged pattern easily supports traceability
vis-à-vis CLF members' allegations that they avoid certain areas
because of Academy's idling -- after all, an individual could
reasonably choose to avoid an area on a given day purely based on
knowledge that Academy often illegally idles in that area. And
this alleged pattern also supports traceability vis-à-vis CLF
members' other asserted injuries: Evidence of twenty-six days of
daily violations substantiates CLF's inference that Academy
illegally idles "each and every day that its buses are in
operation," and Academy's buses have operated throughout the
period for which CLF members allege injuries. Accordingly, we see
no need to show exposure to each individual emission in order to
establish standing to complain of the general and repeated practice
of unlawful idling. Cf. Havens Realty Corp. v. Coleman, 455 U.S.
363, 381 (1982) ("Plainly the claims, as currently alleged, are
based not solely on isolated incidents . . . , but a continuing
violation manifested in a number of incidents . . . ."); see also
- 27 - Laidlaw, 528 U.S. at 184–85 (not requiring the plaintiffs to tie
their injuries to individual discharges of pollutants when the
plaintiffs had alleged "continuous and pervasive" violations);
Int'l Union of Bricklayers & Allied Craftsmen v. Meese, 761 F.2d
798, 803 (D.C. Cir. 1985) ("Appellants need not be omniscient and
pinpoint precisely when and where the next infraction will occur.
The requirement is only that the injury be 'fairly' traceable to
[the complained-of conduct.]"); Texans United, 207 F.3d at 793
(finding traceability for a pattern-or-practice-type claim based,
among other things, on "the frequency with which Crown exceeded
the federal limits on sulfur dioxide emissions at its Pasadena
plant").
IV.
Without a complete record before us, we cannot determine
the extent to which CLF can fend off Academy's motion for summary
judgment on standing. We thus vacate the district court's grant
of summary judgment and remand for the district court, consistent
with this opinion, to (1) determine which, if any, of the second
batch of CLF witness declarations and expert disclosures are part
of the record; (2) make the factual findings necessary to assess
whether CLF's asserted injuries are fairly traceable to the alleged
idling; and (3) apply the correct legal standards for determining
whether CLF has alleged injuries-in-fact and traceability. We
- 28 - leave it to the district court to determine whether and to what
extent to allow further supplementation of the record.
Finally, given the open questions concerning the
record's scope, the alleged injuries-in-fact, and traceability, we
decline the parties' invitations to reach redressability. Should
the district court hold that CLF has satisfied the injury-in-fact
and traceability requirements, it should assess redressability in
the first instance. Costs are awarded to CLF.
- 29 -