Sierra Club v. United States Department of Transportation

United States Court of Appeals
FOR THE DISTRICT OF COLUMBIA CIRCUIT
Argued September 13, 2024 Decided January 17, 2025
No. 20-1317
SIERRA CLUB, ET AL.,
PETITIONERS
v.
UNITED STATES DEPARTMENT OF TRANSPORTATION, ET AL.,
RESPONDENTS
Consolidated with 20-1318, 20-1431, 21-1009
On Petitions for Review of a Final Rule
of the Department of Transportation
Bradley Marshall argued the cause for Environmental
Petitioners. With him on the briefs was Jordan Luebkemann.
Aaron J. Stemplewicz entered an appearance.

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Brian Lusignan, Assistant Solicitor General, Office of the
Attorney General for the State of New York, argued the cause
for State Petitioners. With him on the briefs were Letitia
James, Attorney General, Michael J. Myers, Senior Counsel,
Max Shterngel, Assistant Attorney General, Anthony G.
Brown, Attorney General, Office of the Attorney General for
the State of Maryland, Joshua M. Segal, Assistant Attorney
General, Steven J. Goldstein, Special Assistant Attorney
General, Rob Bonta, Attorney General, Office of the Attorney
General for the State of California, Kavita Lesser, Deputy
Attorney General, Kathleen Jennings, Attorney General,
Office of the Attorney General for the State of Delaware,
Christian Douglas Wright, Director of Impact Litigation,
Kwame Raoul, Attorney General, Office of the Attorney
General for the State of Illinois, Elizabeth Dubats and Jason E.
James, Assistant Attorneys General, Dana Nessel, Attorney
General, Office of the Attorney General for the State of
Michigan, Elizabeth Morrisseau, Assistant Attorney General,
Andrea Joy Campbell, Attorney General, Office of the
Attorney General for the Commonwealth of Massachusetts,
Seth Schofield, Senior Appellate Counsel, Keith Ellison,
Attorney General, Office of the Attorney General for the State
of Minnesota, Peter N. Surdo, Special Assistant Attorney
General, Matthew J. Platkin, Attorney General, Office of the
Attorney General for the State of New Jersey, Lisa Morelli,
Deputy Attorney General, Michelle A. Henry, Attorney
General, Office of the Attorney General for the
Commonwealth of Pennsylvania, Ann R. Johnston, Assistant
Chief Deputy Attorney General, Ellen F. Rosenblum, Attorney
General, Office of the Attorney General for the State of
Oregon, Paul A. Garrahan, Attorney-in-Charge, Steve Novick,
Special Assistant Attorney General, Peter F. Neronha,
Attorney General, Office of the Attorney General for the State
of Rhode Island, Nicholas M. Vaz, Special Assistant Attorney
General, Charity R. Clark, Attorney General, Office of the

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Attorney General for the State of Vermont, Laura B. Murphy,
Assistant Attorney General, Brian L. Schwalb, Attorney
General, Office of the Attorney General for the District of
Columbia, Caroline S. Van Zile, Solicitor General, Robert W.
Ferguson, Attorney General, Office of the Attorney General
for the State of Washington, and Julian H. Beattie, Assistant
Attorney General.
Aaron P. Riensche argued the cause for petitioner Puyallup
Tribe of Indians. With him on the briefs were Richard A. Du
Bey and Nicholas G. Thomas.
Rebecca Jaffe, Attorney, U.S. Department of Justice,
argued the cause for respondents. With her on the brief were
Todd Kim, Assistant Attorney General, Robert Lundman and
Justin Heminger, Attorneys, and Charles E. Enloe, Attorney,
U.S. Department of Transportation.
Before: MILLETT and PAN, Circuit Judges, and
RANDOLPH, Senior Circuit Judge.
Opinion for the Court filed by Circuit Judge PAN.
PAN, Circuit Judge: Liquified natural gas (“LNG”) is
methane gas that is liquified by cooling it to a temperature
of -260° F. The liquification of gas facilitates its transportation
and storage. But LNG is dangerous. If LNG is warmed, it
reverts to a gaseous state, which causes it to expand. Such
expansion can place tremendous pressure on the vessel that
contains the LNG, creating the risk of an explosion. LNG is
also highly flammable. Thus, if it leaks and encounters an
ignition source, it can cause a conflagration that burns at a
temperature of 2,426° F. Moreover, if LNG spills without
igniting, it can form an ultra-cold gas cloud that can spread over
a wide area, severely injuring people and damaging property in
its path.

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LNG typically is transported either by pipeline or by truck.
Shipping LNG by rail has been authorized only on an ad hoc
basis by special permit or approval. But in 2020, the Pipeline
and Hazardous Materials Safety Administration (“PHMSA”)
promulgated a rule authorizing the transportation of LNG by
rail in newly designed tank cars, with no permit required. The
new final rule (“LNG Rule”) imposed no limit on the number
of LNG tank cars that could be included in a single train and
set no mandatory speed limit for trains that carry LNG.
PHMSA noted that one company contemplated a single train
with 80 tank cars containing LNG. During the rulemaking
process, commenters expressed alarm about the potentially
catastrophic consequences of a train derailment in which LNG
tank cars were breached or punctured. For example, a group of
environmental organizations asserted that the amount of energy
contained in 22 tank cars of LNG would be equal to that of the
atomic bomb that was dropped on Hiroshima, Japan, during
World War II. PHMSA nevertheless opined that transporting
LNG by rail under its LNG Rule would have no significant
effect on the environment. It therefore declined to prepare an
environmental impact statement (“EIS”).
A coalition of environmental nonprofits (“Environmental
Petitioners”), a collection of states (“State Petitioners”), and the
Puyallup Tribe of Indians (“the Tribe”) now challenge the LNG
Rule. The petitioners contend that PHMSA did not sufficiently
consider the safety risks of transporting LNG by rail. They
argue, in relevant part, that the National Environmental Policy
Act (“NEPA”) required PHMSA to prepare an EIS, and that its
decision not to do so was arbitrary and capricious. We agree.
We thus grant the petitions, vacate the LNG Rule, and remand
for further proceedings before the agency.

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I.
A.
The Hazardous Materials Transportation Act (“HMTA”)
provides that the Secretary of Transportation “shall prescribe
regulations for the safe transportation . . . of hazardous
material” in commerce. 49 U.S.C. § 5103(b)(1). PHMSA is
the component agency “charged with carrying out the
Secretary’s duties and powers” under the HMTA. Lilliputian
Sys., Inc. v. Pipeline & Hazardous Materials Safety Admin.,
741 F.3d 1309, 1311 (D.C. Cir. 2014) (citing 49 U.S.C.
§ 108(f)). PHMSA has promulgated Hazardous Materials
Regulations to govern the transportation of natural gas and
other hazardous materials. 49 C.F.R. § 171.1(c)(1).
Historically, the Hazardous Materials Regulations have
authorized bulk transport of LNG by pipeline or truck, but not
by rail, except upon the issuance of a special permit or approval
on a case-by-case basis. Hazardous Materials: Liquefied
Natural Gas by Rail, 84 Fed. Reg. 56,964, 56,966 (Oct. 24,
2019) (“Proposed Rule”). But in April 2019, then-President
Trump directed the Secretary of Transportation to propose a
rule to generally “permit LNG to be transported in approved
rail tank cars.” Exec. Order No. 13,868, 84 Fed. Reg. 15,495,
15,497 (Apr. 10, 2019). The Executive Order directed the
Secretary to propose the rule within 100 days and to finalize
the rulemaking within thirteen months. Id.
In October 2019, PHMSA published a notice of proposed
rulemaking. 84 Fed. Reg. 56,964. The Proposed Rule
contemplated the transport of LNG in “120W” tank cars (i.e.,
cars bearing model number DOT-113C120W). Such tank cars
fall within the “DOT-113” class of cars that are designed to
carry “cryogenic liquids” (i.e., refrigerated liquified gases). Id.
at 56,965 (citing 49 C.F.R. § 173.115(g)), 56,967. But never

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before had DOT-113 cars been used to transport the large
volumes of LNG considered by the Proposed Rule.
DOT-113 rail cars have numerous safety features that
reduce the risk of an explosion or the release of cargo. A
boiling liquid expanding vapor explosion (“BLEVE”) is not
triggered by ignition, but instead occurs when a pressurized
container is breached and its contents are exposed to heat,
without any pressure relief. 84 Fed. Reg. at 56,974 n.29. That
causes cryogenic liquid in the container to quickly boil and
release vapor — exploding the container. Id. DOT-113 cars
are designed to minimize the heating of the tank’s contents:
They have a tank-within-a-tank design, with an inner alloy
stainless steel tank and an outer carbon steel tank, separated by
a vacuum and insulation. Id. at 56,967. The thick outer tank is
intended to withstand a collision without being compromised,
which protects the insulating vacuum and thereby prevents the
inner tank from releasing cargo. Id. at 56,975. Additional
safety features include multiple pressure relief valves and
vents. Id. at 56,967, 56,973–74.
The Proposed Rule noted that the DOT-113 car had an
“excellent safety record throughout its 50 years of service,”
during which it had been used to transport ethylene, “another
flammable cryogenic liquid which shares similar chemical and
operating characteristics with LNG.” 84 Fed. Reg. at 56,967.
The Proposed Rule acknowledged, however, that between
1980 and 2017, “there were 14 instances of damage to DOT-
113 tank cars during transportation.” Id. at 56,972. In three of
those instances, cargo escaped because of a breach of both the
outer and inner tanks; while in three other incidents, cargo
escaped because of a failure of the valves or fittings. Id.
To further ensure safety, the Proposed Rule relied on the
existing Hazardous Materials Regulations and voluntary

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industry standards. 84 Fed. Reg. at 56,968. The existing
regulations cited by the Proposed Rule are designed to
“reduc[e] the probability and consequences of a hazardous
material release.” Id. at 56,965. They primarily focus on
ensuring the safe packaging and handling of hazardous
materials during transportation and providing effective
communications about the hazards of what is being shipped.
Id. Meanwhile, the voluntary industry standards are compiled
in a protocol developed by the Association of American
Railroads. The protocol suggests a speed limit of 50 miles per
hour for any train with at least 20 carloads of any hazardous
material. Id. at 56,968–69. As noted, the Proposed Rule
imposed no limit on the number of tank cars that could carry
LNG in a single train.
The Proposed Rule included a preliminary environmental
assessment, which asserted that the rule would not result in any
significant environmental impact. 84 Fed. Reg. at 56,970–75.
The preliminary assessment gave little weight to the potential
hazards of an accident in which LNG might be released. Id. at
56,972–73. After acknowledging the 14 instances of damage
to DOT-113 tank cars during transportation, id. at 56,972, it
concluded that the probability of an accident was low, id. at
56,974.
The Environmental and State Petitioners submitted
comments raising grave safety concerns. They argued that the
Proposed Rule failed to adequately mitigate the dangers
inherent in transporting LNG by rail. Those petitioners
emphasized the risk of a tank car’s failure in a derailment,
which could cause a BLEVE; an inextinguishable pool fire; or
the release of an odorless, extremely cold vapor cloud of LNG
that would “embrittle steel and cause severe burns.” State
Pet’rs Comments 3–4; see also Env’t Pet’rs Comments 7, 22.
They criticized the Proposed Rule for not capping the number

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of LNG cars per train and not imposing a mandatory speed
limit. The Environmental and State Petitioners also argued that
DOT-113 tank cars were not up to the task of transporting
LNG. In particular, they questioned the safety record of the
tank cars, emphasizing that the cars were breached during
transport in 14 prior incidents. The petitioners also urged
PHMSA to await the results of certain ongoing safety studies
conducted by the Federal Railroad Administration, an agency
that PHMSA, by regulation, must cooperate with. See 49
C.F.R. § 1.97(b)(3).
The National Transportation Safety Board (“NTSB”), an
independent federal agency, raised similar concerns. The
NTSB opined that “[b]ecause unit trains of DOT-113 tank cars
carrying large volumes of flammable cryogenic gases have no
operational or accident performance safety history, . . . a
thorough safety assessment of the tank car specification is
needed.” NTSB Comments 3. It added that “given the small
number of DOT-113 tank cars in use, the documented 14
incidents referenced in the [Proposed Rule] in which three shell
breaches occurred between 1980 and 2017 is not a compelling
‘demonstrated safety record.’” Id. at 4.
B.
In July 2020, PHMSA promulgated the final LNG Rule.
The final Rule authorizes transportation of LNG by rail, but it
differs from the Proposed Rule in several respects. First, the
final LNG Rule imposes new requirements for the outer tank
of approved railcars: The outer tank must be both thicker and
made of stronger steel than that used in existing 120W cars.
Specifically, the tanks must be 9/16″ thick, rather than the
current minimum of 7/16″. The outer tank also must be made
of TC-128 Grade B normalized steel, which is less likely to
crack or puncture than the steel typically used in DOT-113

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cars. Hazardous Materials: Liquefied Natural Gas by Rail, 85
Fed. Reg. 44,994, 45,003–04 (July 24, 2020). PHMSA dubbed
this new type of reinforced railcar a “120W9” car. Id. at
44,996. Second, PHMSA boosted the maximum filling density
from 32.5% to 37.3%. Id. at 45,006–07.1 That allows more
LNG to be loaded into each car but reduces the number of cars
needed to ship a given amount of LNG. Id. at 45,014. Finally,
the LNG Rule includes additional operating controls to
promote safety: (1) Tank cars carrying LNG must be equipped
with remote monitoring devices for detecting and reporting
each car’s internal pressure and location; (2) Any train with at
least 20 LNG tank cars in a continuous block or with 35 such
cars throughout the train must be equipped with advanced
braking capabilities; and (3) PHMSA adopted the routing
requirements of 49 C.F.R. § 172.820, which require railroads
to consider safety risk factors, such as population density, when
analyzing potential routes for transporting LNG. Id. at 45,008–
09.
Along with the LNG Rule, PHMSA published a final
Environmental Assessment. The Environmental Assessment
touted the “demonstrated safety record” of DOT-113 tank cars.
J.A. 449. But it acknowledged that “[d]espite the low
probability, rail incidents can be high-consequence events,
given the quantity of hazardous materials in transportation.”
J.A. 450. Nevertheless, the Environmental Assessment
determined that the potential environmental impacts of the
LNG Rule did not “rise to the level of ‘significant’” and that a
more detailed EIS would not be necessary. J.A. 492–97.
1 “Filling density” refers to the percent ratio of the weight of
cargo in the tank to the weight of water that the tank will hold. 49
C.F.R. § 173.319(d)(1). As the government explained, “if a tank car
filled with water would weigh 10,000 pounds, and the filling-density
requirement for a specific material is 50%, then the tank car can hold
5,000 pounds of that particular material.” Gov’t Br. 55 n.9.

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PHMSA also found that the LNG Rule would not have
significant effects on public health and safety, greenhouse gas
emissions, and environmental justice communities.
Environmental Petitioners,2 State Petitioners,3 and the
Tribe all petitioned for review. See Sierra Club v. DOT, No.
20-1317; Maryland v. DOT, No. 20-1318; Puyallup Tribe of
Indians v. PHMSA, No. 20-1431. The Tribe also filed a
petition challenging PHMSA’s denial of its administrative
appeal of the LNG Rule. Puyallup Tribe of Indians v. PHMSA,
No. 21-1009. We consolidated the appeals, and the Tribe and
the State Petitioners adopted the Environmental Petitioners’
argument that the LNG Rule violates NEPA. We have
jurisdiction under 28 U.S.C. § 2342(7).
C.
During the pendency of these appeals, in January 2021,
President Biden directed federal agencies to reconsider Trump
Administration actions that were inconsistent with the Biden
Administration’s climate policies. Exec. Order No. 13,990, 86
Fed. Reg. 7,037 (Jan. 20, 2021). The LNG Rule was one of the
agency actions subject to scrutiny. In November 2021,
PHMSA issued a notice of proposed rulemaking to suspend
authorization of LNG transport by rail. Hazardous Materials:
2 Environmental Petitioners are the Sierra Club, Center for
Biological Diversity, Clean Air Council, Delaware Riverkeeper
Network, Environmental Confederation of Southwest Florida, and
Mountain Watershed Association.
3 State Petitioners are the State of Maryland, State of New York,
State of California, State of Delaware, District of Columbia, State of
Illinois, Commonwealth of Massachusetts, State of Michigan, State
of Minnesota, State of New Jersey, State of Oregon, Commonwealth
of Pennsylvania, State of Rhode Island, State of Vermont, and State
of Washington.

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Suspension of HMR Amendments Authorizing Transportation
of Liquefied Natural Gas by Rail, 86 Fed. Reg. 61,731 (Nov. 8,
2021). In September 2023, PHMSA published a final rule
suspending the LNG Rule until the earlier of June 30, 2025, or
when the agency completes a rulemaking considering
modifications to that rule. Hazardous Materials: Suspension
of HMR Amendments Authorizing Transportation of Liquefied
Natural Gas by Rail, 88 Fed. Reg. 60,356 (Sept. 1, 2023)
(“Suspension Rule”). PHMSA explained that it suspended the
LNG Rule because “uncertainties acknowledged in the July
2020 Final Rule — e.g., regarding the near-term commercial
viability of rail tank car transportation of LNG, as well as
potential safety and environmental benefits and risks of rail
tank car transportation — had only increased since issuance,
thereby ‘cast[ing] doubt on the continued validity of the
balance between potential benefits and public safety and
environmental risks underpinning the [LNG Rule].’” Id. at
60,359 (quoting 86 Fed. Reg. at 61,735–36). Because the LNG
Rule was suspended a few months after it went into effect, rail
transport of LNG under the Rule has never occurred.
PMHSA is currently working on a rulemaking that
considers modifying the LNG Rule. After oral argument, we
ordered the government to provide an update “on the status and
timing of any anticipated new rulemaking.” Sierra Club v.
Dep’t of Transp., No. 20-1317 (D.C. Cir. Sept. 23, 2024). The
government filed a notice informing us that it had not yet
published a proposed amendment of the LNG Rule. The
government added that although PHMSA did not expect to
issue a final rule before June 30, 2025 — the point at which the
LNG Rule would go back into effect — PHMSA had not yet
decided whether to initiate a rulemaking to consider extending
the suspension of the LNG Rule.

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II.
A.
Although no party has questioned the court’s subject
matter jurisdiction over these petitions, “we have an
independent obligation to assure ourselves of our jurisdiction.”
Waterkeeper All., Inc. v. Regan, 41 F.4th 654, 659 (D.C. Cir.
2022). We therefore address three doctrines potentially
implicated in this case: ripeness, mootness, and standing. We
conclude that none bars our jurisdiction here.
1.
“Ripeness is a justiciability doctrine designed ‘to prevent
the courts, through avoidance of premature adjudication, from
entangling themselves in abstract disagreements over
administrative policies, and also to protect the agencies from
judicial interference until an administrative decision has been
formalized and its effects felt in a concrete way by the
challenging parties.’” Nat’l Park Hosp. Ass’n v. Dep’t of
Interior, 538 U.S. 803, 807–08 (2003) (quoting Abbott Lab’ys
v. Gardner, 387 U.S. 136, 148–49 (1967)). The “rationale
underlying the ripeness doctrine” is that “[i]f we do not decide
it now, we may never need to.” Nat’l Treasury Emps. Union v.
United States, 101 F.3d 1423, 1431 (D.C. Cir. 1996).
Accordingly, courts have found cases unripe when the
government represents to the court that it will never enforce the
regulation in question. See, e.g., EPA v. Brown, 431 U.S. 99,
103 (1977) (per curiam) (declining to pass on challenged
regulations when “the federal parties have not merely
renounced an intent to pursue certain specified regulations;
they now appear to admit that those remaining in controversy
are invalid unless modified in certain respects”); Wheaton Coll.
v. Sebelius, 703 F.3d 551, 552–53 (D.C. Cir. 2012) (per
curiam) (ordering cases to be held in abeyance based on

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government’s representation “that it would never enforce [the
challenged regulation] in its current form against the appellants
or those similarly situated” (emphasis in original)).
This case is ripe. Rather than disclaiming any intent to
implement the LNG Rule or conceding its invalidity, PHMSA
continues to defend the Rule. Although it has suspended the
Rule pending the outcome of a new rulemaking process to
modify it, the Rule will go into effect on June 30, 2025, if it is
not modified by that date. PHMSA’s mere suspension of the
Rule does not make this case unripe. We have rejected the
notion that “an agency can stave off judicial review of a
challenged rule simply by initiating a new proposed
rulemaking that would amend the rule in a significant way,”
because “[i]f that were true, a savvy agency could perpetually
dodge review.” Am. Petrol. Inst. v. EPA, 683 F.3d 382, 388
(D.C. Cir. 2012); cf. Am. Petrol. Inst. v. EPA, 906 F.2d 729,
739–40 (D.C. Cir. 1990) (“If the possibility of unforeseen
amendments were sufficient to render an otherwise fit
challenge unripe, review could be deferred indefinitely.”).
2.
Nor does PHMSA’s suspension of the LNG Rule moot this
case. In West Virginia v. Environmental Protection Agency,
the Supreme Court held that a challenge to a final rule was not
moot even though the government maintained that it planned
to promulgate a new rule rather than enforce the rule. 142 S.
Ct. 2587, 2607 (2022). “Voluntary cessation does not moot a
case unless it is absolutely clear that the allegedly wrongful
behavior could not reasonably be expected to recur.” Id.
(cleaned up). Here, the agency does not promise that it will
never enforce the Rule, even though it may, at some point,
amend the Rule. Moreover, the Rule will go into effect on June

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30, 2025, if it is not amended before then. Accordingly, this
case is not moot.
3.
We next turn to standing. “To establish standing,” a party
“must demonstrate (i) that [it] has suffered or likely will suffer
an injury in fact, (ii) that the injury likely was caused or will be
caused by the defendant, and (iii) that the injury likely would
be redressed by the requested judicial relief.” FDA v. All. for
Hippocratic Med., 602 U.S. 367, 380 (2024).
Environmental Petitioners have representational standing
because they are organizations with members who “live, work,
and recreate along the[] rail routes, and who will be harmed by
additional train traffic from LNG trains.” Env’t Pet’rs Br. 18.
Such trains will cause “increased disruption to [the] peace and
quiet members enjoy in their homes and in nearby scenic
areas.” Id.; see also Advocs. for Highway & Auto Safety v. Fed.
Motor Carrier Safety Admin., 41 F.4th 586, 592 (D.C. Cir.
2022) (“An association has standing to bring suit on behalf of
its members if (1) at least one of its members would have
standing to sue in the member’s own right; (2) the interest the
association seeks to protect is germane to its purpose; and (3)
neither the claim asserted nor the relief requested requires the
member to participate in the lawsuit.” (cleaned up)).
The State Petitioners also have Article III standing.
“[L]ike other associations and private parties,” states can suffer
injuries to their proprietary interests that are sufficient to confer
standing. Alfred L. Snapp & Son, Inc. v. Puerto Rico, ex rel.,
Barez, 458 U.S. 592, 601–02 (1982). And just like any other
party, a state cannot “manufacture standing by incurring costs
in anticipation of non-imminent harm.” Clapper v. Amnesty
Int’l USA, 568 U.S. 398, 422 (2013). Nor do states have
standing to sue when the effects of a government regulation on

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their proprietary interests are “indirect” and “attenuated.”
United States v. Texas, 599 U.S. 670, 680 n.3 (2023).
However, when, as here, a regulation causes a state to
undertake “expenditures to mitigate and recover from harms
that could have been prevented” if that regulation had not been
enacted, the state suffers an injury to its proprietary interest
sufficient to confer standing. Air All. Hous. v. EPA, 906 F.3d
1049, 1059–60 (D.C. Cir. 2018). We have applied this
principle to state expenditures to reduce risks related to
“chemical releases in their territory[.]” Id. at 1060.
The LNG Rule causes direct and imminent harm to New
York’s public fisc. New York has already spent $29,000 to
send its firefighters to train at the Massachusetts Firefighting
Academy to take classes focused specifically on how to combat
LNG pool fires. These expenditures will increase significantly
because of the LNG Rule. New York’s Fire Administrator
attests that, if the LNG Rule goes into effect, LNG tank cars
will begin traveling on New York’s roughly 4,500 miles of rail
lines as soon as the second half of 2025, and New York will
begin spending hundreds of thousands of additional dollars on
safety measures to mitigate the risks posed by those rail cars.
The planned safety measures include training additional
firefighters to respond to LNG spills, hiring full-time fire
specialists with expertise in LNG, equipping local fire
departments with methane detectors, and providing local fire
departments with bulk quantities of chemicals used specifically
to extinguish LNG fires.
These expenditures constitute what precedent has long
recognized to be a cognizable proprietary injury to states. This
injury is in no way self-inflicted or premised on speculative
harm. Instead, it involves direct expenses incurred and to be
incurred because of the LNG Rule. The LNG Rule would be a

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but-for cause of substantial LNG rail traffic in New York. And
two states have recently experienced catastrophic DOT-113
rail car accidents leading to breached hulls. See Section II.3.B
infra. Obviously, New York cannot wait until there is an LNG
pool fire in its territory to begin spending funds on safety
measures.
The Tribe also has adequately demonstrated its standing.
The Tribe submitted a comment based on its concern that the
Proposed Rule would lead to the transportation of LNG from a
facility known as Tacoma LNG, which is adjacent to the
Tribe’s reservation. Tacoma LNG’s owner, Puget LNG, has
demonstrated its intent to ship LNG by rail by touting the
facility’s “easy access to . . . rail and roadways” and noting the
“[r]ail spur on site for future potential rail car loading.” J.A.
570.4 The LNG Rule thus substantially increases the
probability that LNG will be shipped by rail from Tacoma LNG
through the Tribe’s reservation, which is home to many Tribe
members, institutions, and cultural or historic sites. The Rule
therefore risks harm to the Tribe’s “heritage, its land, its
4 We disagree with PHMSA’s dismissal of the Tribe’s concerns
as “inapposite.” 85 Fed. Reg. at 45,022–23. The LNG Rule stated
that “it does not appear that rail transportation of LNG to the Tacoma
LNG facility is currently permitted by the terms of” the Washington
State regulator’s authorization and that this authorization also does
not “seem to contemplate rail transportation of LNG from that
facility.” Id. at 45,022. It also asserted that the “schematics of the
Tacoma LNG facility . . . suggest that rail infrastructure neither exists
nor is contemplated at the site.” Id. at 45,023. Yet a Puget LNG
marketing document and the Tribe’s standing declarations show that
rail infrastructure does in fact exist at Tacoma LNG. Moreover,
PHMSA’s suggestion that LNG transport by rail is not covered by
the current authorizations by Washington State focused mainly on a
restriction on importing LNG to the facility rather than the relevant
risk of exporting from the facility.

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people, and its resources.” Tribe Br. 17–18. This increased
risk suffices to demonstrate the Tribe’s standing. See Nat. Res.
Def. Council v. EPA, 464 F.3d 1, 6 (D.C. Cir. 2006) (“[W]e
have recognized that increases in risk can at times be ‘injuries
in fact’ sufficient to confer standing.”); Dep’t of Com. v. New
York, 139 S. Ct. 2551, 2565 (2019) (noting that “future injuries
. . . ‘may suffice if the threatened injury is certainly impending,
or there is a substantial risk that the harm will occur’” (quoting
Susan B. Anthony List v. Driehaus, 573 U.S. 149, 158 (2014)).
B.
The petitioners argue that PHMSA’s decision not to
prepare an EIS was arbitrary and capricious because it ignored
the significant environmental consequences of the LNG Rule.
They claim that PHMSA failed to take a hard look at how the
LNG Rule would affect public safety and therefore violated
NEPA. In support of their argument, they note that PHMSA
disregarded the checkered safety record of the 120W tank car
and ignored the risks of including numerous cars of LNG
within a single train without any required speed limit. We
agree and vacate the LNG Rule. We therefore need not reach
the other challenges to the LNG Rule raised by the petitioners.5
5 The State and Environmental Petitioners also argue that
PHMSA violated NEPA’s public participation requirement by
adopting in the final Rule a novel tank car design and increased
filling density, without any notice; violated the Hazardous Materials
Transportation Act’s requirement to prioritize safety; violated the
Administrative Procedure Act by arbitrarily and capriciously
disregarding safety concerns; and violated the APA’s notice-and-
comment requirements. In addition, they argue that PHMSA failed
to consider the Rule’s effects on greenhouse gas emissions and
environmental justice communities. The Tribe contends that
PHMSA’s failure to prepare an EIS was arbitrary and capricious

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NEPA requires an agency to prepare an EIS whenever it
proposes a “major Federal action[] significantly affecting the
quality of the human environment.” 42 U.S.C. § 4332(C). The
EIS must “discuss[] in detail the environmental impact of the
proposed action, alternatives to the action, and other
considerations.” Myersville Citizens for a Rural Cmty., Inc. v.
FERC, 783 F.3d 1301, 1322 (D.C. Cir. 2015) (citing 42 U.S.C.
§ 4332(C)). An EIS is necessary unless the agency finds “no
significant impact” on the environment. Standing Rock Sioux
Tribe v. Army Corps of Eng’rs, 985 F.3d 1032, 1039 (D.C. Cir.
2021); see also 42 U.S.C. § 4332(C). “If any significant
environmental impacts might result from the proposed agency
action, then an EIS must be prepared before agency action is
taken.” Standing Rock, 985 F.3d at 1039 (emphasis in original)
(cleaned up).
An agency’s decision not to prepare an EIS will be
overturned “only if it was arbitrary, capricious or an abuse of
discretion.” Grand Canyon Tr. v. FAA, 290 F.3d 339, 340
(D.C. Cir. 2002), as amended (Aug. 27, 2002) (cleaned up). A
court’s role in reviewing that decision “is a limited one,
designed primarily to ensure that no arguably significant
consequences have been ignored.” Myersville Citizens, 783
F.3d at 1322 (cleaned up). Accordingly, a court asks “whether
the agency (1) has accurately identified the relevant
environmental concern, (2) has taken a hard look at the
problem in preparing its [environmental assessment], (3) is
able to make a convincing case for its finding of no significant
impact, and (4) has shown that even if there is an impact of true
significance, an EIS is unnecessary because changes or
safeguards in the project sufficiently reduce the impact to a
because it failed to consider the LNG Rule’s disparate impact on the
Tribe. It also argues that PHMSA failed to adequately consult with
it about the LNG Rule.

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minimum.” Id. (cleaned up). NEPA requires an agency to
“look at both the probabilities of potentially harmful events and
the consequences if those events come to pass.” Standing
Rock, 985 F.3d at 1049 (cleaned up).
In this case, PHMSA determined that an EIS was not
required because authorizing LNG transport by rail under the
LNG Rule would have no significant impact on the
environment. But the record reflects that transporting LNG by
rail poses a low-probability but high-consequence risk of a
derailment that could seriously harm the environment: A
breach of one or more rail cars containing LNG could cause an
explosion, an inferno, or the spread of a freezing, flammable,
suffocating vapor cloud. The real possibility of such
catastrophes significantly affects the quality of the human
environment. For that reason, NEPA required PHMSA to
prepare an EIS.
PHMSA’s consideration of the probability of a rail
accident involving LNG tank cars was demonstrably
inadequate. We have noted that “a finding of no significant
impact is appropriate only if a grave harm’s probability is so
low as to be remote and speculative, or if the combination of
probability and harm is sufficiently minimal.” Standing Rock,
985 F.3d at 1049 (cleaned up). Here, a derailment resulting in
the release of LNG was undoubtedly a “grave harm”; and the
risk of that happening was neither “so low as to be remote and
speculative” nor “sufficiently minimal” under the
circumstances. Id. PHMSA found only that there was a “low
probability” of a high-consequence rail accident, J.A. 446–50,
which was plainly insufficient to support a finding of no
significant impact under our precedents.
The effects of a rail accident that breached one or more
LNG tank cars could be dire, if not cataclysmic. The

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Environmental Assessment acknowledged two potentially
significant scenarios in which LNG could be released: (1) an
“[a]ccident release causing outer tank damage resulting [in]
vapor release from pressure relief device,” and (2) an
“[a]ccident release causing outer and inner tank damage
resulting in large release/spill.” J.A. 457. The Environmental
Assessment explained that each possibility could have a “high
consequence.” Id. It noted that the controlled venting of vapor
from a pressure relief device in the first scenario is less
concerning than the unmanaged release of the entire cargo, but
the vapor could catch fire as it is released. Alternatively, it
noted, if LNG spilled and ignited, the LNG would burn at
2,426° F and imperil everything in the vicinity. Absent an
ignition source, the LNG would rapidly vaporize into an
odorless, flammable gas cloud that would crawl along the
ground until eventually warming to the ambient air temperature
— or igniting. There is also the possibility of a BLEVE,
although PHMSA considered a BLEVE “highly unlikely.”
J.A. 456.
The risk of such a “high consequence” derailment is real.
The Environmental Assessment identified two derailments
within a four-year period in which both the inner and outer
tanks of DOT-113 rail cars were breached. Because two such
incidents have already occurred, the risk of a third is neither
remote nor speculative. See Carolina Env’t Study Grp. v.
United States, 510 F.2d 796, 799 (D.C. Cir. 1975) (probability
of an accident that ranges from one in 100,000 to one in a
billion is “remote”). The first incident occurred in Moran,
Kansas, in 2011. A train going 46 miles per hour came upon a
broken rail and suddenly applied its emergency brakes,
derailing three DOT-113 cars that contained refrigerated
ethylene. Two of the cars were breached and went up in
flames. Although the third car was not breached, its pressure
relief valves began venting gas, which caught fire from an

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adjacent car’s blaze. In the second incident, two cars carrying
refrigerated argon — which is not flammable — derailed in
Mer Rouge, Louisiana, in 2014. One of the derailed cars was
a DOT-113 tank car, and damage from the derailment caused
the breach of its inner tank and the release of argon. 85 Fed.
Reg. at 45,005. Neither event caused any injuries or fatalities,
but neither event involved LNG. Id.
The prior performance of DOT-113 cars does not suggest
a minimal risk of accidents, despite PHMSA’s frequent touting
of their “excellent safety record.” See, e.g., 85 Fed. Reg. at
45,003. The information relied upon by PHMSA addresses
how the tank cars withstood the impacts of previous train
derailments, but not the probability that future derailments
would occur. Moreover, “[g]iven the small number of DOT-
113 tank cars in use,” NTSB concluded that the cars do not
have “a compelling ‘demonstrated safety record.’” NTSB
Comments 4. The considered concerns of a “highly specialized
governmental agenc[y]” like the NTSB carry relevant weight
when determining whether an EIS is required. Nat’l Parks
Conservation Ass’n v. Semonite, 916 F.3d 1075, 1085 (D.C.
Cir.), amended on reh’g in part, 925 F.3d 500 (D.C. Cir. 2019);
Standing Rock, 985 F.3d at 1043.
Although the past accidents considered by PHMSA did not
result in injury or death, PHMSA’s focus on the “generally low
consequences” of those accidents is misplaced because the
prior incidents involved the derailment of only two or three
railcars that were carrying ethylene and argon. J.A. 449. By
contrast, LNG is a particularly hazardous material and may be
transported in an unlimited number of tank cars per train under
the LNG Rule. Indeed, the Environmental Assessment
recognized that “neither cryogenic ethylene nor cryogenic
argon is transported in the quantities that are possible for the
transport of LNG” under the LNG Rule. J.A. 450. And “the

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risks associated with hazardous materials transportation rise
with quantity.” J.A. 495. As we previously have explained, if
an agency seeks to depart from past practice, it cannot use
minimal past harm to “brush[] away” safety concerns, but must
instead “look forward to examine the effects of” the change.
New York v. Nuclear Regul. Comm’n, 681 F.3d 471, 481 (D.C.
Cir. 2012) (emphasis in original). It must also consider
whether the lack of past injury was only “because of site-
specific factors or even sheer luck.” Id. PHMSA made no
effort to take those considerations into account.
Nor has PHMSA shown that “even if there is an impact of
true significance, an EIS is unnecessary because changes or
safeguards in the project sufficiently reduce the impact to a
minimum.” Myersville Citizens, 783 F.3d at 1322 (cleaned up).
The LNG Rule fails to ameliorate the risk of accidents. First,
it does not impose a mandatory speed limit on trains carrying
LNG cars. The faster the train, the greater the risk that a tank
car will crack or puncture if there is a derailment. Yet the LNG
Rule relies on a nonbinding, recommended speed limit of 50
miles per hour that only kicks in when a train has 20 or more
cars of hazardous materials. See 85 Fed. Reg. at 45,007; see
also id. at 45,018. Even that voluntary standard may be
insufficient because breaches of DOT-113 rail cars have
occurred at speeds below 50 miles per hour, such as in the
Kansas accident.
Second, PHMSA declined to cap the number of LNG tank
cars per train. 85 Fed. Reg. at 45,005. Danger increases with
the number of tank cars in a single train, as the failure of one
could trigger the “[c]ascading [f]ailure of [m]ultiple” cars. J.A.
459. For example, in the Kansas incident, LNG that was vented
from a pressure relief valve caught fire from an adjacent car’s
blaze. Responders had to intentionally breach the tank car in a
“controlled vent and burn process.” J.A. 450. Yet even as

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PHMSA acknowledged that “rail incidents can be high-
consequence events, given the quantity of hazardous materials
in transportation,” J.A. 450, and noted that one operator
planned to string together at least 80 cars per train, 85 Fed. Reg.
at 45,005, it found that the Rule posed no significant
environmental impact.
Although PHMSA adopted some safety measures in the
LNG Rule — including requiring thicker outer tanks made of
higher-quality steel — it never explained why those safety
measures were adequate to address the extreme dangers
associated with a derailment. To the contrary, one of
PHMSA’s own safety studies raised concerns about the
efficacy of the 120W9 design. In that study, PHMSA
compared three similar derailment accidents involving cars
with tanks of either 9/16″ or 7/16″ thickness. 85 Fed. Reg. at
45,005–06. The thicker cars had between 62–69% fewer
punctures than the thinner ones. Id. But a quarter of the thicker
cars were still breached. Id. As previously discussed, any
breach of a rail car containing LNG could be disastrous.
In sum, transporting LNG by rail entails a potent
combination of risk and extreme danger that plainly has a
significant impact on the environment. Although the
probability of an accident “may be low, that risk is sufficient
that a person of ordinary prudence would take it into account
in reaching a decision to approve the [agency action], and its
potential consequences are therefore properly considered
here.” Standing Rock, 985 F.3d at 1050 (cleaned up).
PHMSA’s decision not to prepare an EIS was therefore
arbitrary and capricious.6
6 Of course, while we hold that the LNG Rule raises substantial
environmental questions that required preparation of an EIS, we
express no opinion on the wisdom of any particular set of safety

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* * *
Because PHMSA failed to prepare an EIS as required, we
vacate the LNG Rule and remand to PHMSA for further
proceedings. Remand with vacatur is the ordinary remedy for
unlawful agency action, United Steel v. Mine Safety & Health
Admin., 925 F.3d 1279, 1287 (D.C. Cir. 2019), and the
government has not asked us to depart from the ordinary course
here.
So ordered.
protocols. NEPA is “primarily information-forcing,” so it “directs
agencies only to look hard at the environmental effects of their
decisions, and not to take one type of action or another.” Sierra Club
v. FERC, 867 F.3d 1357, 1367 (D.C. Cir. 2017) (cleaned up). After
preparing an EIS, the agency will be best positioned to determine
whether the environmental risk is worth taking. Any future legal
challenges to the substance of that decision would then be brought
under some other statute, not NEPA. Because we vacate the instant
LNG Rule due to PHMSA’s failure to prepare an EIS, such questions
are left for another day.

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