Clean Fuels Alliance America v. Environmental Protection Agency

United States Court of Appeals
FOR THE DISTRICT OF COLUMBIA CIRCUIT
Argued September 30, 2025 Decided March 13, 2026
No. 20-1107
CLEAN FUELS ALLIANCE AMERICA,
PETITIONER
v.
ENVIRONMENTAL PROTECTION AGENCY,
RESPONDENT
AMERICAN FUEL & PETROCHEMICAL MANUFACTURERS, ET
AL.,
INTERVENORS
Consolidated with 20-1113
On Petitions for Review of a Final Action
of the Environmental Protection Agency
David M. Lehn argued the cause for petitioners. With
him on the briefs were Bryan Killian and Douglas A. Hastings.
Claire H. Chung entered an appearance.
Kimere J. Kimball, Attorney, U.S. Department of Justice,
argued the cause for respondents. With her on the brief were

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Adam R.F. Gustafson, Principal Deputy Assistant Attorney
General, Tsuki Hoshijima, Attorney, and Lucas May, Attorney,
U.S. Environmental Protection Agency.
Elizabeth B. Dawson argued the cause for intervenors
American Fuel & Petrochemical Manufacturers, et al. With
her on the brief were Jonathan G. Hardin, Alexandra Magill
Bromer, Michael R. Huston, Robert J. Meyers, Richard S.
Moskowitz, and Tyler J. Kubik. Karl J. Worsham entered an
appearance.
Before: MILLETT, WILKINS, and GARCIA, Circuit Judges.
Opinion for the Court filed by Circuit Judge GARCIA.
GARCIA, Circuit Judge: Under the Clean Air Act’s
Renewable Fuel Standard (RFS) Program, EPA directs the fuel
industry to introduce a certain volume of renewable fuel into
commerce each year. To meet these annual goals, EPA
promulgates standards that prescribe a percentage of each
refinery’s fuel output that must consist of renewable fuel.
This case began in 2020 as a challenge to EPA’s 2020
percentage standards. But it was then held in abeyance for
several years. In the interim, both petitioners’ requested relief
and the legal landscape have materially changed. Because
those developments have mooted this case, we dismiss the
consolidated petitions.
I
This court has repeatedly described the RFS Program in
depth. See Ctr. for Biological Diversity v. EPA, 141 F.4th
153, 162–65, 163 n.1 (D.C. Cir. 2025) (per curiam). We
include here only those details that are necessary to understand
our disposition.

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A
Created in 2005, the RFS Program is administered by EPA
and requires a certain target “volume of renewable fuel” to be
“sold or introduced into commerce in the United States” each
year. 42 U.S.C. § 7545(o)(2)(A)(i). To that end, EPA
calculates annual “percentage standards” that determine how
much renewable fuel “obligated parties”—refiners and
importers of transportation fuel—must introduce each year.
See Ctr. for Biological Diversity, 141 F.4th at 163 (explaining
how entities may comply). In general terms, EPA calculates
the standards by “divid[ing] the applicable [target] volume . . .
by an estimate of the national volume of non-renewable
transportation fuel that will be used that year.” Sinclair Wyo.
Refin. Co. v. EPA, 101 F.4th 871, 881 (D.C. Cir. 2024).
The statute also allows certain small refineries to apply “at
any time” for exemption from a particular year’s standard if
that standard presents a “disproportionate economic hardship.”
42 U.S.C. § 7545(o)(9)(B)(i). Those exemptions affect the
accuracy of EPA’s percentage standard formula. Unless EPA
adjusts “the denominator—the nation’s total supply of
petroleum-based transportation fuel”—to exclude the volume
produced by exempted refineries, that denominator will be
“artificially inflated.” Sinclair Wyo., 101 F.4th at 881. With
the denominator “inflated,” applying the resulting percentage
standards to nonexempt refiners and importers will not achieve
the applicable renewable fuel target. See id.
Prior to 2020, EPA adjusted each year’s percentage
standard to account for any small refinery exemptions that had
been granted before the Agency published that year’s standard
(which by statute must be done by November 30 of the
preceding year). See id. If the Agency granted a refinery
exemption before promulgating the standard, it adjusted its
projection of total fuel output to exclude that refinery’s

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projected output. But the Agency also frequently grants
exemptions after a percentage standard is promulgated. And
EPA did not account for those so-called “retroactive
exemptions.” Id.
In 2020, EPA altered its approach. It began adjusting the
percentage standards to account not only for already-granted
exemptions, but also for the retroactive exemptions it expected
to grant after promulgation. See Renewable Fuel Standard
Program: Standards for 2020 and Biomass-Based Diesel
Volume for 2021 and Other Changes, 85 Fed. Reg. 7,016,
7,049 (Feb. 6, 2020) (2020 Rule). EPA reasoned that it could
better “ensure” achievement of the applicable volume goal for
a given year if it relied on a more accurate estimate of the
number of participating obligated parties and their expected
total output. See id. at 7,050. To codify this change, EPA
amended terms in the regulatory formula used to calculate the
percentage standards so that the denominator reflected the
exemptions the Agency “projected” would be granted in a
given compliance year. Id.; see 40 C.F.R. § 80.1405(c).
Still, EPA did not go as far as some had urged. Although
the new formula would largely prevent shortfalls caused by
future retroactive exemptions, it did not require EPA to account
for the shortfall caused by all the past retroactive exemptions
for which the Agency had made no adjustments in prior years.
B
Twelve different petitions for review were promptly filed
in this court challenging the 2020 Rule. As relevant here,
various renewable fuel producers and trade associations argued
that the Rule should be set aside because EPA also needed to
account for the past retroactive exemptions. Those
exemptions, they averred, translated to approximately 4.73
billion gallons of renewable fuel that should have been
introduced in past years but were not. They argued that the

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2020 percentage standard should be increased to make up for
that past shortfall, which would in turn increase demand for
renewable fuel.
But proceedings then ground to a halt—the consolidated
petitions were held in abeyance for three and a half years. A
primary cause of that delay was a 2022 rulemaking in which
EPA revisited the 2020 Rule and the 2020 percentage standard.
See Renewable Fuel Standard (RFS) Program: RFS Annual
Rules, 87 Fed. Reg. 39,600, 39,632 (July 1, 2022) (2022 Rule).
The 2022 Rule “reaffirm[ed]” the 2020 Rule’s formula
changes—that is, the decision to project retroactive exemptions
moving forward, but not to account for past ones. Id. It also
recalculated the 2020 compliance year standards using updated
data. Id. at 39,633–35.
The 2022 Rule was itself challenged in this court. Certain
traditional fuel refiners argued that it was unlawful for EPA to
project the total number of small refinery exemptions that
would be granted for a given compliance year and adjust the
percentage standards accordingly. Sinclair Wyo., 101 F.4th at
890–91. The two petitioners that now remain in this case—
Growth Energy and Clean Fuels Alliance America—
intervened to defend that feature of the 2022 Rule. Notably,
those petitioners did not challenge the 2022 Rule for again
announcing that EPA would not account for past retroactive
exemptions. That case was decided in 2024, and we upheld
the Rule. Id.
Meanwhile, the statutory framework underlying
petitioners’ legal challenge shifted substantially. Through
2022, the target annual renewable fuel volumes for the RFS
Program were dictated by Congress in a schedule set forth at
42 U.S.C. § 7545(o)(2)(B)(i)(I). EPA’s authority to “waive”
that target volume was limited to circumstances of “severe[]
harm [to] the economy or environment” or “inadequate

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domestic supply” of renewable fuel. Id. § 7545(o)(7)(A).
But post-2022, the statute gives EPA the authority to set the
applicable volume goals. See id. § 7545(o)(2)(B)(ii). Under
the newly operative provisions, the applicable volume for a
given year “shall be determined by the [EPA] Administrator,
in coordination with the Secretary of Energy and the Secretary
of Agriculture, based on” certain considerations. Id. Those
considerations include, among other things, environmental
impacts, costs to consumers, and “the implementation of the
[RFS] program” thus far. Id. We have recognized that the
statute now grants EPA “considerable discretion to weigh and
balance the various factors” when determining the annual
volume goals. Ctr. for Biological Diversity, 141 F.4th at 171
(citation omitted). Further, the mandate for EPA to achieve
the applicable volume goals specifically by means of
percentage standards expired at the end of 2021. 42 U.S.C.
§ 7545(o)(3)(B)(i).
In 2024, after the challenge to the 2022 Rule was decided,
this case was removed from abeyance. Most of the parties that
had initially challenged the 2020 Rule voluntarily dismissed
their petitions. Only Growth Energy and Clean Fuels Alliance
America remain. They have abandoned their initial request
that the court remand the 2020 Rule to EPA for it to recalculate
and raise the 2020 percentage standards, which were
superseded by the 2022 Rule. Instead, they reframe their
challenge as addressing EPA’s “policy” of refusing to account
for past retroactive exemptions. Petitioners’ Brief 1. As they
explained at oral argument, petitioners no longer seek a
judgment requiring EPA to “go back and change the 2020
standards . . . or any past standards.” Tr. of Oral Arg. 25.
Instead, their petitions are now “about changing how EPA
operates in the future.” Id.

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II
EPA argues that this case is moot, and alternatively
submits that petitioners waived or forfeited their challenge to
EPA’s policy by not raising it in the litigation over the 2022
Rule. Because we agree that the case is moot, we do not reach
the latter question, much less the merits.
EPA’s mootness argument is straightforward: Petitioners
challenged the 2020 Rule, but that Rule has been superseded
by the 2022 Rule. This argument has substantial force:
Typically, when one agency action “has been superseded by a
subsequent” one, a challenge to the original action is “plainly
moot.” Alaska v. U.S. Dep’t of Agric., 17 F.4th 1224, 1226
(D.C. Cir. 2021) (cleaned up). Here, the 2022 Rule
superseded the 2020 Rule by recalculating the percentage
standards for calendar year 2020. The 2022 Rule also
revisited the 2020 Rule’s changes to the percentage standards
formula and expanded on EPA’s rationale for those changes.
See 87 Fed. Reg. at 39,632–33. EPA was explicit that it had
“chosen not to reallocate exempt volume from [small refinery
exemptions] for past years,” and its 2022 Rule “constitute[d]”
the Agency’s “final and complete response to [petitioners’
2020] petition.” J.A. 117; Tr. of Oral Arg. 8–10.
Although petitioners could have raised their same
concerns regarding past retroactive exemptions in a challenge
to the 2022 Rule, they did not do so. Quite the opposite:
They intervened and chose to defend that rule from a traditional
fuel industry challenge. See Sinclair Wyo., 101 F.4th at 882,
890. What is more, petitioners argued to this court that “EPA
must adjust the standards to account for all exemptions, and its
reaffirmed formula reasonably fulfills that duty. EPA must
‘ensure’ that the required volumes are met, and adjusting the
standards to reflect reasonably projected exemptions does so,
even if the projection proves inaccurate.” Biofuel

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Intervenors’ Brief 2, Sinclair Wyo., 101 F.4th 871 (No. 22-
1210) (emphasis added).
Petitioners respond that the 2022 Rule mooted only their
challenge to the 2020 percentage standards, not their challenge
to EPA’s “policy” of refusing to account for past retroactive
exemptions in its annual rulemakings. They emphasize that
although the 2022 Rule revisited the 2020 Rule’s amendments
to the percentage standards formula, it “reaffirm[ed]” the 2020
Rule and left the formula unchanged. See 87 Fed. Reg. at
39,632; 40 C.F.R. § 80.1405(c). Petitioners thus argue that
the court could and should declare EPA’s “policy” unlawful in
a way that would require EPA to account for past exemptions
in its future annual rulemakings. See, e.g., Reply Brief 4–5
(“If the Court agrees with petitioners, EPA will have to
conform its policy to that ruling and apply its revised policy in
future standard-settings . . . .”).
Petitioners base this response on three of our decisions, of
which American Maritime Ass’n v. United States, 766 F.2d 545
(D.C. Cir. 1985) is illustrative. There, the petitioners
challenged an interim rule, and the agency promulgated a final
rule while the case was pending. Although the final rule
superseded the interim rule and the petitioners could have filed
a new suit challenging that rule, we held the case was not moot.
The final rule had “reaffirm[ed]” and “basically adopt[ed]” the
interim rule’s approach on the relevant issue, and so the
petitioners’ challenges were “equally applicable to the final
rule and the interim rule.” Id. at 554 n.14; see also Union of
Concerned Scientists v. Nuclear Regul. Comm’n, 711 F.2d 370,
379 (D.C. Cir. 1983) (similar); Motor & Equip. Mfrs. Ass’n v.
Nichols, 142 F.3d 449, 459 (D.C. Cir. 1998) (finding that a
challenge to agency action was not moot where portions of the
regulations that informed that action were amended but others
were “unaffected by [the] intervening amendments”).
Petitioners here argue that because EPA continues to refuse to

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account for past retroactive exemptions in its annual
rulemakings, its challenge to the 2020 Rule is “equally
applicable” to EPA’s future rulemakings and therefore not
moot under these authorities.
There may be many reasons those cases are inapposite
here. But the combined force of three considerations suffices
to distinguish them.
First, in each of those cases, the petitioner asked this court
to set aside an identifiable past agency action. In American
Maritime, that was the final rule that superseded the interim
rule the petitioners initially challenged. This case would at
least be in the same ballpark as American Maritime if
petitioners had asked us to set aside the 2022 Rule. But they
do not. Instead, they ask us to issue a purely prospective
opinion to guide future agency action. Accordingly,
petitioners’ request sounds far closer to an impermissible
request for an advisory opinion than the requests in the cases
on which petitioners rely. See Pub. Citizen, Inc. v. FERC, 92
F.4th 1124, 1128 (D.C. Cir. 2024) (“Among other salutary
purposes, [mootness doctrine] protects courts from rendering
impermissible advisory opinions.”); Nat’l Wildlife Fed’n v.
Hodel, 839 F.2d 694, 742 (D.C. Cir. 1988) (“It would be
entirely inappropriate for this court to . . . issue an advisory
opinion to guide the Secretary’s rulemaking.”). Indeed, the
Clean Air Act provision from which our jurisdiction derives
authorizes this court to “review” and “reverse” certain
“action[s] of the Administrator.” 42 U.S.C. § 7607(d)(9)
(emphasis added). It is far from clear that petitioners’
request—having disclaimed any effort to set aside the 2020
Rule or any other specific EPA action—fits that bill.
Second, and in marked contrast to petitioners’ authorities,
the legal challenge petitioners raised against the 2020 Rule is
not “equally applicable” to the future rulemakings they ask us

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to guide. Recall that EPA essentially calculates the
percentage standards by dividing the annual volume target by
the industry’s total expected fuel output for that year. When
these petitions were filed in 2020, the statute provided a
numerator for that formula—30 billion gallons in 2020, 33
billion in 2021, and 36 billion in 2022. 42 U.S.C.
§ 7545(o)(2)(B)(i)(I). Now, however, the EPA Administrator
“determine[s]” the required annual volumes based on a range
of statutory considerations that includes the past
“implementation of the [RFS] program,” costs to consumers,
and environmental considerations. Id. § 7545(o)(2)(B)(ii).
That change plainly affects the legal analysis petitioners
ask us to conduct. Petitioners argued that EPA’s duty to
“ensure[]” achievement of congressionally specified targets
required it to make up for past exemptions. Id.
§ 7545(o)(3)(B)(i). The crux of the parties’ dispute was
whether and to what extent the statute indirectly suggested
EPA had a measure of discretion on that issue. But EPA’s
duty now is to “ensure” achievement of targets EPA itself has
broad discretion to determine. The newly operative
provisions are at minimum in tension with petitioners’
argument that the statute implicitly requires EPA to account for
past retroactive exemptions in any particular way. And that
feature of the legal analysis was not presented by the 2020 Rule
and thus by these petitions.
Perhaps because this case was initiated and litigated in the
context of the 2020 Rule, no party has meaningfully addressed
the impact of these statutory changes. But given those
changes, petitioners’ challenge to the 2020 Rule is not “equally
applicable” to the future rulemakings they ask us to address.
Even if the “policy” petitioners ask us to proscribe remained
the same, the law we must apply to evaluate that alleged
“policy”—the operative provisions of the RFS statute—has
materially changed. Indeed, viewing the case prospectively as

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petitioners request, one might say that the legal question
petitioners present—whether the statute imposes a mandatory
duty to account for past exemptions under the statutory
provisions in effect in 2020—no longer exists. Cf. People for
the Ethical Treatment of Animals, Inc. v. Gittens, 396 F.3d 416,
422–23 (D.C. Cir. 2005) (tethering mootness analysis to “the
legal questions” a suit “presents for decision”); Nat’l Mining
Ass’n v. Dep’t of Interior, 251 F.3d 1007, 1011 (D.C. Cir.
2001) (holding that material revision to challenged regulations
during litigation mooted aspect of case because “the new rules
add[ed]” features that would “affect[] the [legal] calculus,”
such that the court could not proceed “as if nothing has
changed”).1
Third, as petitioners noted in an emergency motion to
hold this case in abeyance filed just before oral argument, EPA
is actively considering—in rulemaking for the 2026 and 2027
compliance years—whether to account for many past
retroactive exemptions using its new authority to set the target
fuel volume. Renewable Fuel Standard (RFS) Program:
Standards for 2026 and 2027, Partial Waiver of 2025 Cellulosic
Biofuel Volume Requirement, and Other Changes;
Supplemental Notice of Proposed Rulemaking, 90 Fed. Reg.
45,007, 45,007 (Sept. 18, 2025) (proposing a “reallocation,” in
full or in part, of volumes associated with 2023 and 2024
exemptions). That action is not yet finalized and may itself be
challenged in litigation. But EPA’s proposal raises doubts that
EPA will even continue following the “policy” from the 2020
Rule that petitioners ask us to review. See Mot. for Abeyance
1 (Sep. 22, 2025) (“These actions endorse the programmatic
1 Further, although EPA has so far chosen to continue using the
formula codified at 40 C.F.R. § 80.1405(c) to impose percentage
standards on obligated parties, EPA is no longer required to issue
percentage standards at all. See 42 U.S.C. § 7545(o)(3)(B)(i).

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logic underlying petitioners’ claim here . . . .”). Just as in
Alaska, the need to “speculate about future actions by
policymakers” undermines our jurisdiction. 17 F.4th at 1229.2
Our rationale is narrow. Petitioners ask us to opine on the
propriety of a supposed agency “policy” disconnected from
any particular agency action, when the operative statutory
provisions have changed mid-litigation in ways that bear
directly on the legal question petitioners raised, and when it is
not clear the agency even adheres to the same policy petitioners
initially challenged. None of the authorities they have
identified involved remotely analogous circumstances. We
accordingly conclude that the default mootness rule for
superseded agency action governs.
This ruling of course does not prohibit petitioners from
presenting a version of their legal challenge to EPA in the
concrete setting of a specific future annual rulemaking. If
petitioners do so, then EPA and, if necessary, a reviewing court,
could assess that argument in the context of the statute as it
operates today.
III
The petitions for review are dismissed as moot.
So ordered.
2 Petitioners might have invoked our caselaw finding that
challenges are not moot when a party seeks declaratory relief from
an “ongoing policy,” as opposed to or in addition to relief targeting
a particular agency action. See Crowley Gov’t Servs., Inc. v. Gen.
Servs. Admin., 143 F.4th 518, 530–31 (D.C. Cir. 2025). But we
have similarly never applied that mootness exception where, as here,
the relevant legal landscape has materially changed, much less when
it is unclear whether the agency even has an “ongoing policy” in the
relevant sense.

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