El Puente v. United States Army Corps of Engineers

United States Court of Appeals
FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued January 25, 2024 Decided May 3, 2024

No. 23-5189

EL PUENTE, ET AL.,
APPELLANTS

v.

UNITED STATES ARMY CORPS OF ENGINEERS, ET AL.,
APPELLEES

Appeal from the United States District Court
for the District of Columbia
(No. 1:22-cv-02430)

Emily Jeffers argued the cause for appellants. With her on
the briefs were Catherine Kilduff and Marc Fink.

Christophe Courchesne and Jaclyn Lopez were on the
brief for amici curiae Toabajeños en Defensa del Ambiente, et
al. in support of appellants.

Kevin W. McArdle, Attorney, U.S. Department of Justice,
argued the cause for appellees. With him on the brief were
Todd Kim, Assistant Attorney General, Rachel Heron and
Christopher C. Hair, Attorneys, and Rachel D. Gray, Senior
Civil Works Attorney, U.S. Army Corps of Engineers.
 2
Before: WALKER and PAN, Circuit Judges, and ROGERS,
Senior Circuit Judge.

Opinion for the Court filed by Circuit Judge PAN.

PAN, Circuit Judge. The U.S. Army Corps of Engineers
(“the Corps”) plans to dredge San Juan Harbor to widen and
deepen the channels through which ships travel. The project
will facilitate the movement of large ships — such as cruise
ships, cargo ships, and petroleum tankers — that currently
cannot navigate the Harbor or cannot do so easily. The
dredging will take approximately a year to complete. The
Corps plans to use barges to transport the dredged material
from the Harbor to an offshore dumping site.

The Corps published an Environmental Assessment,
which concluded that the dredging project would not have a
significant impact on the environment. And the National
Marine Fisheries Service (“the Service”) determined that the
project was not likely to adversely affect certain threatened and
endangered species, including seven types of coral. Three
environmental groups sued the agencies, asserting that they had
failed to adequately consider the project’s environmental toll.
The district court granted summary judgment in favor of the
defendant agencies. Because the Corps and the Service did not
act arbitrarily or capriciously in carrying out their
responsibilities to evaluate environmental concerns, we affirm.

I.

A.

The National Environmental Policy Act (“NEPA”)
required the Corps to assess the environmental impacts of its
plan to dredge San Juan Harbor before authorizing the project.
See 42 U.S.C. § 4321 et seq.; Theodore Roosevelt
 3
Conservation P’ship v. Salazar, 616 F.3d 497, 503–04 (D.C.
Cir. 2010). To comply with its NEPA obligations, the Corps
prepared an Environmental Assessment, which found that the
project would not significantly impact the environment and
thus allowed the Corps to bypass issuing a more in-depth
Environmental Impact Statement. See Sierra Club v. Peterson,
717 F.2d 1409, 1412–13 (D.C. Cir. 1983); 40 C.F.R. § 1508.9.1
The Corps published the draft Environmental Assessment,
provided a 45-day period of public review and comment, and
held a public meeting about the Environmental Assessment in
San Juan. Thereafter, the “Integrated Feasibility Report &
Environmental Assessment” was finalized in July 2018, and
the Corps issued its formal “finding of no significant impact”
in November 2018.

In relevant part, the Corps’s Environmental Assessment
addressed the following four issues:

(1) Transition to Liquid Natural Gas (“LNG”): The
Assessment considered the dredging project’s facilitation of a
potential shift in Puerto Rico’s energy market to increased use
of LNG. In the early stages of project planning, and well before
the publication of the draft Environmental Assessment, the
Puerto Rico Electric Power Authority (“PREPA”) informed the
Corps that it intended to construct an LNG terminal on San
Juan Harbor, which would receive and process imported LNG
that would be used by two existing power plants that would be
converted to natural-gas facilities. Due to the size of the
tankers that are used to transport LNG, the construction of an
LNG terminal and conversion of the power plants would not be

1
Except where otherwise noted, we cite the NEPA regulations in
effect in 2018 when the Corps published the Environmental
Assessment. Those regulations have since been amended. See 85
Fed. Reg. 43,304 (July 16, 2020); 87 Fed. Reg. 23,453 (Apr. 20,
2022).
 4
viable unless the Harbor were dredged. Based on PREPA’s
expressed intentions, the Corps recognized in its
Environmental Assessment that “a transition to LNG is a
reasonable future assumption.” J.A. 191. But it emphasized
that “[t]here is a level of uncertainty surrounding PREPA’s
conversion to LNG and the timing of the conversion” due to
many factors, including PREPA’s bankruptcy, calls to privatize
PREPA, and the impacts of recent hurricanes. Id. The Corps
thus determined that the project was economically justified
whether or not PREPA converted the two power plants to
natural-gas facilities. But the Environmental Assessment did
not analyze the environmental impacts of LNG development.

(2) Cumulative Impacts: The Corps discussed the
“cumulative impacts” of the project, as required by NEPA. See
40 C.F.R. § 1508.7 (defining “cumulative impact” as “the
impact on the environment which results from the incremental
impact of the action when added to other past, present, and
reasonably foreseeable future actions regardless of what
agency (Federal or non-Federal) or person undertakes such
other actions”). The Corps looked specifically at two related
actions by the U.S. Coast Guard — the expansion of an
anchorage area and the relocation of buoys in the Harbor — to
determine if the project, when combined with those related
actions, would have adverse cumulative impacts on the
environment. Ultimately, the Corps explained that “[p]otential
cumulative impacts on many resources were considered as part
of this study and the majority of these resources were
determined to have little risk of being cumulatively impacted.”
J.A. 228; see also id. (“These [resources that were considered]
included land use, terrestrial natural resources, threatened or
endangered species, other fish and wildlife, managed fishes,
the estuarine water column, certain water quality parameters
(turbidity and hazardous and toxic constituents), sediments
(hazardous and toxic constituents), coastal barrier resources,
 5
harbor shorelines (of properties adjacent to the project),
dredged material, air quality, noise, aesthetics, cultural and
historic resources, native American resources, environmental
justice, and recreation.”).

(3) Environmental Justice: As required by executive
order, the Environmental Assessment included an
“environmental justice” analysis that evaluated the project’s
impact on minority and low-income populations. See J.A. 272–
75; Executive Order 12,898, § 1-101, 59 Fed. Reg. 7,629 (Feb.
11, 1994) (requiring agencies to “make achieving
environmental justice part of [their] mission[s] by identifying
and addressing, as appropriate, disproportionately high and
adverse human health or environmental effects of [their]
programs, policies, and activities on minority populations and
low-income populations”). In the original analysis, the Corps
considered the effects of the dredging project on marginalized
communities within a one-mile radius of the Port of San Juan
(not the entire Harbor). The Corps later updated its
environmental-justice analysis in a January 2023 supplemental
environmental assessment. The supplemental assessment was
prepared in connection with a proposed expansion of the
project to dredge an additional area, which the Corps ultimately
declined to pursue. The updated analysis encompassed
environmental-justice communities in areas within a one-mile
and five-mile radius of San Juan Harbor.

(4) Coral: Fourth and finally, the Environmental
Assessment analyzed the potential impact of the project on
seven threatened species of coral. In particular, the Assessment
examined the extent to which the process of dredging the
Harbor and transporting the dredged material to the open ocean
would increase turbidity and/or sedimentation — that is, how
much it would muddy the water — and thereby harm or kill
corals. The Corps determined that none of the threatened coral
 6
species had been documented within either the construction
footprint or a 150-meter indirect impact zone, but that there
might be some coral near the entrance of the Harbor, along the
routes that vessels would take to dispose of dredged material.
Accordingly, the Corps determined that it was unlikely that any
increase in turbidity and/or sedimentation from the project
would significantly affect threatened corals. The Corps also
committed to taking steps to ensure that corals would be
protected, including (1) conducting additional surveys to
determine the precise location of any corals along the disposal
routes, (2) using turbidity-monitoring stations near threatened
corals along the route, and (3) adopting operational controls to
limit the amount of dredged material spilled during transport.

The Endangered Species Act (“ESA”) required the Corps
to consult with the Service regarding the impact of the dredging
project on threatened and endangered species. See 16 U.S.C.
§ 1536(a)(2). When the two agencies first conferred, the
Service stated that it could not concur with the Corps’s
determination that the proposed project was not likely to
adversely affect threatened corals. The Service requested more
information and then engaged in discussions with the Corps
that led to some adjustments of the dredging plans to better
protect the corals, including the development of a turbidity-
monitoring plan. The Service then changed its position and
issued a Biological Opinion, which found in relevant part that
the project was not likely to adversely affect the threatened
coral species. Like the Corps, the Service noted that video
surveys revealed no corals within the dredging areas and that
the Corps would monitor turbidity along the disposal route
during the project.
 7
B.

El Puente de Williamsburg, CORALations, and the Center
for Biological Diversity (collectively, “Appellants”) filed a
lawsuit challenging the dredging project in August 2022,
naming as defendants the Corps, the Service, the U.S. Fish and
Wildlife Service, and certain administrators. The Complaint
included nine claims alleging various violations of NEPA, the
ESA, the Clean Water Act, and the Administrative Procedure
Act (“APA”).

In early 2023, the parties filed cross-motions for summary
judgment. The district court issued a detailed opinion ruling in
favor of the defendants, concluding that they did not act
arbitrarily, capriciously, or contrary to any environmental
statute in fulfilling their obligations to examine the
environmental impacts of the dredging project.2 The district
court’s order resolved only seven of the nine claims alleged in
the complaint — Counts 3 and 9 remained outstanding.
Accordingly, the district court issued a minute order requiring
the parties to file a joint status report on the outstanding counts.
In response, the parties filed a joint stipulation of voluntary
dismissal of Counts 3 and 9 under Federal Rule of Civil
Procedure 41(a)(1)(A)(ii). Appellants then filed the instant
appeal.

II.

The parties agree that we have jurisdiction to hear this
appeal, but we must independently “assure ourselves of our
jurisdiction.” In re Brewer, 863 F.3d 861, 868 (D.C. Cir.
2017). The district court had federal question jurisdiction
under 28 U.S.C. § 1331. But we lacked jurisdiction over the

2
On appeal, Appellants challenge only the judgment in favor of
the Corps, the Service, and their associated officials.
 8
appeal at the time it was filed because the district court’s initial
summary judgment order resolved only seven of the nine
counts. See Dukore v. District of Columbia, 799 F.3d 1137,
1140 (D.C. Cir. 2015) (“[W]hen a district court resolves some,
but not all, of the claims in a complaint, the judgment is
generally non-final and non-appealable.”). The parties’
stipulation to voluntarily dismiss the remaining two counts did
not create a final appealable order because any dismissal was
presumptively without prejudice, see Fed. R. Civ. P.
41(a)(1)(B), and “voluntary but non-prejudicial dismissals of
remaining claims [are] generally insufficient to render final and
appealable a prior order disposing of only part of the case.”
Blue v. D.C. Pub. Schs., 764 F.3d 11, 17 (D.C. Cir. 2014); see
also Robinson-Reeder v. Am. Council on Educ., 571 F.3d 1333,
1339 (D.C. Cir. 2009); cf. Shatsky v. Palestine Liberation Org.,
955 F.3d 1016, 1026–27 (D.C. Cir. 2020) (articulating an
exception involving certain dismissals of all claims against one
party that predate judgment as to the claims against remaining
parties).

After we brought the jurisdictional issue to the parties’
attention and they filed a joint motion for entry of judgment in
the district court, the district court entered summary judgment
on Counts 3 and 9, thereby resolving all the claims in the case.
As a result, we now have jurisdiction because the district court
has entered a final and appealable order. See 28 U.S.C. § 1291.
We treat the premature notice of appeal as filed on the date that
the district court resolved all of Appellants’ claims by granting
summary judgment on the outstanding counts. See Fed. R.
App. P. 4(a)(2); Outlaw v. Airtech Air Conditioning & Heating,
Inc., 412 F.3d 156, 159 (D.C. Cir. 2005); Capitol Sprinkler
 9
Inspection, Inc. v. Guest Servs., Inc., 630 F.3d 217, 221–23
(D.C. Cir. 2011).

III.

We review the district court’s grant of summary judgment
“de novo, as if the agency’s decision had been appealed to this
court directly.” Gerber v. Norton, 294 F.3d 173, 178 (D.C. Cir.
2002) (internal quotations omitted).

We will set aside agency action based on a NEPA or ESA
violation if the action was “arbitrary, capricious, an abuse of
discretion, or otherwise not in accordance with law.” 5 U.S.C.
§ 706(2)(A); see PEER v. Hopper, 827 F.3d 1077, 1081 (D.C.
Cir. 2016). “[O]ur task is not to flyspeck [the agencies’]
environmental analysis for any deficiency no matter how
minor,” but instead “to ensure that the agency has adequately
considered and disclosed the environmental impact of its
actions.” Sierra Club v. DOE, 867 F.3d 189, 196 (D.C. Cir.
2017) (cleaned up). An agency’s action is arbitrary and
capricious if it has failed to “examine the relevant data and
articulate a satisfactory explanation for its action including a
rational connection between the facts found and the choice
made.” Del. Riverkeeper Network v. FERC, 753 F.3d 1304,
1313 (D.C. Cir. 2014) (cleaned up). As the parties challenging
agency action, Appellants bear the burden to show that the
action was arbitrary or capricious. UnitedHealthcare Ins. Co.
v. Becerra, 16 F.4th 867, 882 (D.C. Cir. 2021).

IV.

NEPA “requir[es] federal agencies to take a hard look at
their proposed actions’ environmental consequences.” Sierra
Club v. DOE, 867 F.3d at 196 (cleaned up). NEPA is
“primarily information-forcing”; it “directs agencies only to
look hard at the environmental effects of their decisions, and
 10
not to take one type of action or another.” Sierra Club v.
FERC, 867 F.3d 1357, 1367 (D.C. Cir. 2017) (cleaned up). In
other words, “NEPA is essentially procedural, designed to
ensure fully informed and well-considered decisions by federal
agencies.” Sierra Club v. DOE, 867 F.3d at 196 (cleaned up).
Rather than “dictate particular decisional outcomes,” the
statute “merely prohibits uninformed — rather than unwise —
agency action.” Id.

Appellants argue that the Corps and the Service failed to
take the necessary “hard look” at the environmental effects of
the dredging project. Their challenges largely fall into three
categories: (1) segmentation issues, in which Appellants
contend that the Corps failed to adequately consider the breadth
of the project’s impacts and improperly looked at smaller
“segments” of the government’s actions; (2) environmental-
justice issues, in which Appellants argue that the Corps erred
in analyzing how the project would affect minority and low-
income communities and failed to make the comment process
sufficiently accessible; and (3) coral issues, in which
Appellants criticize the agencies’ scientific analyses regarding
the project’s impact on certain threatened species of coral.

A.

Applicable regulations ensure that an agency cannot
“impermissibly segment its NEPA analysis” by “dividing one
project into multiple individual actions each of which
individually has an insignificant environmental impact, but
which collectively have a substantial impact.” Del.
Riverkeeper Network, 753 F.3d at 1314–15 (cleaned up); see
40 C.F.R. § 1508.25. Thus, under NEPA regulations, the
Corps was “required to include connected actions, cumulative
actions, and similar actions in [the] Environmental
Assessment.” Myersville Citizens for a Rural Cmty., Inc. v.
 11
FERC, 783 F.3d 1301, 1326 (D.C. Cir. 2015) (internal
quotations omitted); 40 C.F.R. § 1508.25(a). Of these three
types of actions, Appellants challenge only the Corps’s alleged
failure to consider a “connected” action — namely, the
potential construction of an LNG terminal. “Connected
actions” are actions that “are closely related and therefore
should be discussed in the same [assessment].” 40 C.F.R.
§ 1508.25(a)(1).3

The Corps also was required to consider the dredging
project’s direct, indirect, and cumulative impacts. 40 C.F.R.
§ 1508.25(c). The second two types of impacts are relevant to
this appeal. Indirect impacts (or indirect effects) “are caused
by the action and are later in time or farther removed in
distance, but are still reasonably foreseeable.” Id. § 1508.8(b);
see also id. (“Effects and impacts as used in these regulations
are synonymous.”). Cumulative impacts are “the impact[s] on
the environment which result[] from the incremental impact of
the action when added to other past, present, and reasonably
foreseeable future actions regardless of what agency (Federal
or non-Federal) or person undertakes such other actions.” Id.
§ 1508.7; see also id. (“Cumulative impacts can result from
individually minor but collectively significant actions taking
place over a period of time.”). Our caselaw instructs that:

[A] meaningful cumulative impact analysis
must identify (1) the area in which the effects of
the proposed project will be felt; (2) the impacts

3
By regulation, “[a]ctions are connected” if they meet one of
three criteria: (i) They “[a]utomatically trigger other actions which
may require environmental impact statements;” (ii) they “[c]annot or
will not proceed unless other actions are taken previously or
simultaneously;” or (iii) they “[a]re interdependent parts of a larger
action and depend on the larger action for their justification.” 40
C.F.R. § 1508.25(a)(1). Appellants rely on the second of these.
 12
that are expected in that area from the proposed
project; (3) other actions — past, present, and
proposed, and reasonably foreseeable — that
have had or are expected to have impacts in the
same area; (4) the impacts or expected impacts
from these other actions; and (5) the overall
impact that can be expected if the individual
impacts are allowed to accumulate.

Del. Riverkeeper Network, 753 F.3d at 1319.

Appellants contend that the Corps improperly
“segment[ed]” its analysis. See 40 C.F.R. §§ 1508.25(a), (c);
Del. Riverkeeper Network, 753 F.3d at 1313. Specifically,
Appellants claim that the Environmental Assessment should
have considered the potential conversion of existing power
plants to LNG facilities as a connected action and an indirect
effect. Appellants further assert that the Corps’s cumulative-
impact analysis should have taken account of the potential for
LNG conversion; and that the cumulative-impact analysis also
was inadequate for the independent reasons that the Corps
failed to define the geographic scope of the impacts and to
sufficiently analyze the effect of other projects on the region.
Appellants’ arguments based on LNG conversion are forfeited
because they were not raised before the agency. See Dep’t of
Transp. v. Pub. Citizen, 541 U.S. 752, 764 (2004). Although
the remaining arguments about cumulative impacts are
preserved, they fail because the Corps adequately explained
and supported its conclusion that there was little risk that any
cumulative impacts would be significant.

1. Forfeiture of LNG Arguments

Appellants claim that the Corps should have considered
the potential construction of an LNG terminal and its
environmental consequences. See Reply Br. 3 (“Whether
 13
characterized as a connected action, a reasonably foreseeable
project that must be included in the cumulative impacts
analysis, or a reasonably foreseeable indirect effect of the
dredging project, the Corps was required to consider the
environmental consequences of this planned LNG terminal
construction and operation in the Assessment.”). But we need
not reach the merits of any claims based on LNG conversion
because they are forfeited.4

Agency challengers, like Appellants, generally may not
raise NEPA arguments for the first time in litigation; instead,
they must “structure their participation [at the administrative
stage] so that it alerts the agency to the parties’ position and
contentions, in order to allow the agency to give the issue
meaningful consideration.” Pub. Citizen, 541 U.S. at 764
(cleaned up). “[F]ailure to do so ‘forfeit[s] any objection’ to
the environmental analysis on that ground.” Sierra Club v.
FERC, 827 F.3d 36, 51 (D.C. Cir. 2016) (quoting Pub. Citizen,
541 U.S. at 764) (alteration in original). Here, Appellants
never argued to the Corps that it must consider the
environmental impacts of a potential shift to LNG. They
therefore have forfeited their LNG arguments and we reject
those arguments on that basis.

Appellants argue that the LNG issues are properly before
us for two reasons, but neither is convincing. First, Appellants
note that an attorney for environmental and community groups,
after attending the Corps’s public hearing, sent an email to

4
Although the district court addressed the LNG arguments on the
merits and did not discuss forfeiture, the Corps preserved its
forfeiture argument in summary-judgment briefing below and raises
it again on appeal. See ECF No. 22 at 19 (Cross-Motion for
Summary Judgment); Gov’t Br. 24. We “can affirm a judgment on
any basis adequately preserved in the record below.” U.S. ex rel.
Heath v. AT&T, Inc., 791 F.3d 112, 123 (D.C. Cir. 2015).
 14
project administrators “[a]ttach[ing] . . . some of the documents
[she] mentioned concerning LNG deliveries to Puerto Rico.”
J.A. 449. But those documents relate to the “Aguirre Offshore
Gasport” — an LNG project off the southern coast of Puerto
Rico that is seemingly unrelated to the San Juan dredging
project, which is located along the northern coast. The cited
documents thus did not “alert[] the agency to the parties’
position” that the draft Environmental Assessment should have
evaluated environmental impacts of LNG conversion near the
Harbor. Pub. Citizen, 541 U.S. at 764 (cleaned up).

Second, Appellants argue that the Environmental
Assessment’s “flaws [were] so obvious that there is no need for
a commentator to point them out specifically in order to
preserve its ability to challenge a proposed action.” Pub.
Citizen, 541 U.S. at 765. We are unpersuaded. As an initial
matter, the exception for “obviousness” is narrow. It appears
that neither we nor the Supreme Court has ever used the “so
obvious” language from Public Citizen to revive a forfeited
argument. To the contrary, on the rare occasions when we
previously cited that language, we concluded that it did not
justify forgiving forfeiture under the circumstances. See New
York v. Nuclear Regul. Comm’n, 681 F.3d 471, 482 (D.C. Cir.
2012) (concluding that failure to consider non-health
environmental effects of nuclear waste storage and disposal,
such as decrease in property values and harm to a Native-
American community’s homeland, was not so obvious as to
obviate the need to raise the issue before the agency); see also
Pub. Citizen, 541 U.S. at 765 (concluding the agency’s failure
to evaluate un-raised alternatives to the proposed rulemaking
was not an obvious flaw).

In any event, the asserted need to analyze the
environmental impacts of LNG conversion was far from
“obvious” in this case. Although potential LNG conversion
 15
was discussed as the dredging project was planned, those
general discussions did not make it “obvious” that the
environmental impacts of LNG conversion should be
considered as a “connected action,” “cumulative impact,” or
“indirect effect” of the project. In fact, the potential
construction of an LNG terminal did not appear to warrant
detailed consideration due to the uncertainty that the
construction would occur: At the time that the Corps prepared
the Environmental Assessment, PREPA had not initiated any
federal-permit application or requested any federal action
related to potential LNG conversion; and PREPA itself faced
potential privatization, bankruptcy, and the debilitating effects
of two hurricanes. See El Puente v. Army Corps of Eng’rs, --
F. Supp. 3d --, 2023 WL 4706152, *10–11 (D.D.C. July 24,
2023) (district court rejecting LNG arguments on the merits).
Moreover, the Corps convincingly argues that it was not
required to consider the potential impact of LNG conversion,
at least as a “connected action,” because the Corps has no
regulatory authority over the construction or operation of LNG
terminals. See 15 U.S.C. § 717b(e)(1) (conferring authority
over the construction of LNG terminals to the Federal Energy
Regulatory Commission); Ctr. for Biological Diversity v.
FERC, 67 F.4th 1176, 1185 (D.C. Cir. 2023) (declining to
adopt a reading of “connected actions” that “would require the
[agency] to consider the indirect effects of actions beyond its
delegated authority”). Thus, the Environmental Assessment’s
failure to consider the environmental effects of potential LNG
conversions was not an “obvious” flaw. Pub. Citizen, 541 U.S.
at 765. We therefore conclude that Appellants forfeited their
LNG arguments, and we decline to consider them.

2. Cumulative Impacts Analysis

NEPA required the Corps to consider not just the impacts
of the project itself, but the “cumulative impacts” of the project
 16
when combined with other actions affecting the environment.
Regulations define a “cumulative impact” as “the impact on the
environment which results from the incremental impact of the
action when added to other past, present, and reasonably
foreseeable future actions regardless of what agency (Federal
or non-Federal) or person undertakes such other actions.” 40
C.F.R. § 1508.7. Our precedent provides further guidance,
requiring a cumulative-impact analysis to “identify,” among
other things, “the area in which the effects of the proposed
project will be felt,” and “other actions — past, present, and
proposed, and reasonably foreseeable — ” that have impacted
or will impact that area. Del. Riverkeeper Network, 753 F.3d
at 1319. Appellants contend that the Corps’s cumulative-
impact analysis failed to take account of those necessary
considerations. We disagree.

Appellants first argue that the Corps did not identify “the
area in which the effects of the proposed project will be felt” in
the cumulative-impacts section of the Environmental
Assessment, as mandated by Delaware Riverkeeper Network,
753 F.3d at 1319. Although the Corps did not specify an
affected region in its cumulative-impact analysis, it broadly
defined the Environmental Assessment’s “study area” as San
Juan Harbor and various federal channels and terminals
surrounding the Harbor. See J.A. 94, 96; see also id. at74 (“The
San Juan Harbor, Puerto Rico study area encompasses the bar
(entrance) channel, inner harbor channels, offshore dredged
material placement sites, beneficial use dredged material
placement sites, and any extension of the water bodies and
shorelines that could be impacted by proposed
improvements.”). Although we have recognized that an agency
may identify a broader region for its cumulative-impacts
analysis, Sierra Club v. FERC, 38 F.4th 220, 233–34 (D.C. Cir.
2022), we have not previously required a cumulative-impact
analysis to expressly designate a region of impact that is
 17
different from the Environmental Assessment’s “study area.”
Appellants suggest that cumulative impacts may extend to a
broader area than direct or indirect effects, but they do not
develop an argument that the Assessment’s “study area” was
arbitrary and capricious (either in general or as applied to the
cumulative-impacts analysis). Given our deferential standard
of review, we can discern the path taken by the agency and find
it sufficient: The Corps identified a “study area” for the overall
Assessment, and we can infer that the study area also was the
affected region assessed in the cumulative-impact analysis.
See Jost v. Surface Transp. Bd., 194 F.3d 79, 85 (D.C. Cir.
1999) (“We will . . . uphold a decision of less than ideal clarity
if the agency’s path may reasonably be discerned.” (quoting
Motor Vehicle Mfrs. Ass’n v. State Farm Mut. Auto. Ins. Co.,
463 U.S. 29, 43 (1983)); see also Sierra Club v. FERC, 38 F.4th
at 234 (“Making this selection [of the location to examine in
the cumulative-impacts analysis] demands a high level of
technical expertise and is properly left to the informed
discretion of the responsible federal agencies.” (cleaned up)).

Appellants next argue that the Corps failed to identify
enough “past, present, . . . and reasonably foreseeable” other
actions, and thus could not analyze the cumulative impacts of
the dredging project when combined with such actions. See
Delaware Riverkeeper, 753 F.3d at 1319. But as Appellants
admit, the Corps did identify two other actions — the proposed
expansion of an anchorage area and the relocation of certain
buoys — and determined that “the net contribution to
cumulative adverse impacts due to the proposed project and the
overall cumulative adverse impact will be appropriately
minimized.” J.A. 228. The Corps also extensively detailed the
existing conditions in the Harbor elsewhere in the Assessment,
and then — in the cumulative-impacts section — summarized
its conclusion: “Potential cumulative impacts on many
resources were considered as part of this study and the majority
 18
of these resources were determined to have little risk of being
cumulatively impacted.” Id. Under the circumstances, the
Corps’s analysis in the Environmental Assessment was
sufficient.

B.

A long-standing executive order “require[s] federal
agencies to include environmental-justice analysis in their
NEPA reviews.” Sierra Club v. FERC, 867 F.3d at 1368; see
Executive Order 12,898, § 1-101, 59 Fed. Reg. 7,629 (Feb. 11,
1994). The environmental-justice analysis forces agencies “to
consider whether the projects they sanction will have a
‘disproportionately high and adverse’ impact on low-income
and predominantly minority communities.” Sierra Club v.
FERC, 867 F.3d at 1368; see also Executive Order 12,898, §
3-302(a) (requiring agencies to collect and analyze
demographic data “to determine whether their . . . activities
have disproportionately high and adverse human health or
environmental effects on minority populations and low-income
populations”). As for the geographic scope of the
environmental-justice analysis — that is, what low-income and
minority communities to consider — “an agency’s delineation
of the area potentially affected by the project must be
reasonable and adequately explained, . . . and include a rational
connection between the facts found and the decision made.”
Vecinos para el Bienestar de la Comunidad v. FERC, 6 F.4th
1321, 1330 (D.C. Cir. 2021) (cleaned up). “[A] petitioner may
challenge an agency’s environmental justice analysis as
arbitrary and capricious under NEPA and the APA.” Id.

Appellants take issue with three elements of the Corps’s
environmental-justice analysis: (1) its geographic scope, (2) the
availability of public participation, and (3) the purportedly
 19
inadequate disclosure of the project’s impacts on water and air
quality. We take each in turn.

1. Geographic Scope

In conducting its initial environmental-justice analysis as
part of the 2018 Environmental Assessment, the Corps limited
the scope of its review to a one-mile radius around the Port of
San Juan. But in 2023, as part of a supplemental environmental
assessment undertaken when the Corps considered expanding
the project, the Corps prepared a supplemental environmental-
justice analysis that defined the “project area” as the entire San
Juan Harbor and analyzed effects to environmental-justice
communities in both a one-mile and five-mile “buffer zone”
around the Harbor. J.A. 1155–57.

Appellants argue that the geographic scope of the initial
environmental-justice analysis in the Environmental
Assessment was too narrow, but they do not dispute the
adequacy of the expanded geographic scope in the
supplemental analysis. Thus, the issue before us is whether we
can consider the 2022 supplemental analysis, as the district
court did and as the Corps asks us to do. Appellants contend
that the later analysis is an impermissible post-hoc
rationalization. See DHS v. Regents of the Univ. of Cal., 140
S. Ct. 1891, 1909 (2020). They note that a reviewing court
“must judge the propriety of agency action solely by the
grounds invoked by the agency” at the time of the action.
Calcutt v. Fed. Deposit Ins. Corp., 598 U.S. 623, 624 (2023)
(cleaned up).

To start, the agency performed the supplemental analysis
as part of its evaluation of a good-faith proposal to expand the
project’s dredging footprint. See 40 C.F.R § 1502.9(d)(1)
(2022). Indeed, such a supplemental analysis must be
published as part of a formal administrative record, see id.
 20
§ 1502.9(d)(3) (2022), which we are required to consider when
evaluating the agency’s action, Calcutt, 598 U.S. at 628.
Because the Corps did not commission the supplemental
analysis just to address a perceived shortcoming in its prior
work, the facts here do not fit the pattern of a typical post-hoc
rationalization. See, e.g., Regents of Univ. of Cal., 140 S. Ct.
at 1908 (rejecting post-hoc rationalization where agency head
offered “additional explanation for [a prior] decision” and thus
only “elaborate[d] on the reasons for the initial [action] rather
than tak[ing] new administrative action”); Alpharma, Inc. v.
Leavitt, 460 F.3d 1, 11 n.11 (D.C. Cir. 2006) (concluding that
reasons for agency action raised for first time in appellate brief
are “post hoc rationalizations . . . , and we are barred from
considering them” (cleaned up)); Ass’n of Civilian Technicians
v. Fed. Lab. Rels. Auth., 269 F.3d 1112, 1117 (D.C. Cir. 2001)
(“Post-hoc rationalizations, developed for litigation[,] are
insufficient.”).

Moreover, it would make little sense for us to remand for
the Corps to broaden the scope of the environmental-justice
analysis contained in the initial Environmental Assessment
because the agency has already conducted the broader analysis
in the supplemental assessment. See Better Gov’t Ass’n v.
Dep’t of State, 780 F.2d 86, 91 (D.C. Cir. 1986) (“[W]e cannot
order the appellee departments to do something they have
already done.”). We have declined to order injunctive relief
under analogous circumstances, where an agency failed to
timely file an environmental impact statement with Congress,
as required by NEPA, but later prepared and filed an adequate
statement. Realty Income Tr. v. Eckerd, 564 F.2d 447, 457
(D.C. Cir. 1977).5 We therefore conclude that we may properly

5
Appellants rely heavily on a Ninth Circuit case that
distinguished Realty Income Trust and vacated and remanded an
 21
rely on the 2022 environmental-justice supplemental analysis
in determining that the relief Appellants seek with respect to
the original analysis would be “inappropriate,” regardless of
any initial error. Id.

Appellants argue that, even if we can consider it, the
supplemental analysis does not defeat their challenge because
it addressed only the impacts of proposed additional dredging,
not the dredging that had already been approved in 2018. But
that argument misunderstands the record. Although the
supplemental environmental assessment generally “evaluate[d]
only the dredging of a new area,” J.A. 1090; see also id. at
1128, that is not the case for the supplemental environmental-
justice analysis. The Corps announced in its supplemental
environmental assessment that it had decided not to pursue the
expanded dredging, and the related supplemental
environmental-justice analysis assessed the impact of the
project only as authorized (that is, without the additional
dredging). It concluded that the project, not the proposed
expansion, “will not have disproportionately high or adverse
impacts on low income or minority communities.” Id. at 1155–
56; see also id. at 1127 (“[I]n response to comments, the
[Corps] updated the [environmental-justice] footprint to cover
a one- and five-mile radius around the full harbor deepening
area . . . . Based on this updated [environmental-justice]
analysis, the [Corps] has still determined that the project will
not result in disproportionately high or adverse impacts on low
income or minority communities.”).

In sum, even if we assume that the geographic scope of the
2018 environmental-justice analysis was arbitrary or

agency decision even though the agency prepared a post-hoc
environmental assessment. See Metcalf v. Daley, 214 F.3d 1135,
1145–46 (9th Cir. 2000). To the extent these cases conflict, we are
bound by our court’s precedent.
 22
capricious, the 2022 supplemental analysis cured that flaw and
rendered any additional relief unnecessary and improper.

2. Language / Comment Period

Appellants next argue that “[t]he Corps failed to
effectively disclose all expected impacts to local
communities,” Appellants Br. 28, because (1) it did not
translate all materials into Spanish, and (2) it did not extend the
comment period for the Environmental Assessment when
Hurricanes Irma and Maria struck Puerto Rico.

The Corps’s decision not to translate the draft
Environmental Assessment and all related materials into
Spanish was not arbitrary and capricious. The most relevant
portion of the Executive Order on environmental justice makes
this a discretionary call: “Each Federal agency may, whenever
practicable and appropriate, translate crucial public documents,
notices, and hearings relating to human health or the
environment for limited English speaking populations.”
Executive Order 12,898, § 5–5(b) (emphasis added); see
United States v. McIlwain, 931 F.3d 1176, 1180 (D.C. Cir.
2019) (“The word ‘may’ clearly connotes discretion.” (quoting
Halo Elecs., Inc. v. Pulse Elecs., Inc., 579 U.S. 93, 103 (2016)).
Instead of translating the materials, the Corps took other steps:
It sent letters in Spanish about the draft environmental
assessment to interested parties; it orally provided an overview
of the draft in Spanish at the public meeting; and it offered to
make the Spanish version of the public-meeting presentation
available to the public afterwards. The Corps’s decision not to
do more — such as to translate the lengthy draft Environmental
Assessment in its entirety — was not arbitrary or capricious.

As for the comment period, although one commenter
asked whether it would be extended, the Corps did not receive
any formal requests for an extension of time to comment, and
 23
no one attempted to submit late comments. Under those
circumstances, the Corps’s decision not to extend the deadline
or to solicit late comments on its own accord was not arbitrary
or capricious.

3. Oil Spills / Pollution

Finally, Appellants briefly argue that the Corps did not
“effectively . . . disclose the environmental impacts of a
proposed project,” Nat. Res. Def. Council, Inc. v. Nuclear
Regul. Comm’n, 685 F.2d 459, 487 n.149 (D.C. Cir. 1982),
because “the Corps failed to disclose all the expected adverse
impacts in these [environmental-justice] areas, including the
potential concentration of pollutants and the risk of bigger oil
spills from larger tankers.” Appellants Br. 29. But the
environmental-justice analysis did address the cited concerns:
It stated that “[n]o long term adverse direct or indirect impacts
from noise or air emissions are expected as a result of the . . .
Project,” and that “[t]he Project will increase the security,
safety, and efficiency of the San Juan Harbor.” J.A. 1156
(emphases added). Elsewhere in the record, the Corps also
noted that the project will “reduc[e] the potential for ship
groundings and subsequent oil spills.” Id. at 903. The Corps
thus adequately considered pollutants and oil spills and
disclosed their related impacts.

C.

Lastly, we turn to the agencies’ analysis of the project’s
impact on seven threatened species of coral. Appellants’ coral-
related claims arise under NEPA and the ESA. NEPA required
the Corps to “[b]riefly provide sufficient evidence and analysis
for . . . [its] finding of no significant impact” in its
Environmental Assessment. 40 C.F.R. § 1508.9(a)(1).
Relatedly, the ESA directed the Corps to consult with the
Service to determine whether the planned dredging and related
 24
activities would adversely affect any endangered or threatened
species. An “informal consultation” is permissible if the
agency conducting a project (here, the Corps) determines that
the project “is not likely to adversely affect listed species,” and
the Service concurs in that determination. 50 C.F.R.
§§ 402.13(c); 402.14(b)(1). But if the action “may affect an
endangered species,” the ESA requires a more in-depth “formal
consultation” between the agencies. Ctr. for Biological
Diversity v. EPA, 861 F.3d 174, 178 (D.C. Cir. 2017) (citing 50
C.F.R. § 402.14(a)–(b)) (internal quotations omitted). In
carrying out the consultation process, the agencies must use the
“best scientific and commercial data available.” 16 U.S.C.
§ 1536(a)(2).

Applying those statutory frameworks, the Corps made a
“finding of no significant impact” on the environment under
NEPA, see 40 C.F.R. § 1508.9, and the Service concurred in a
related finding that the project “is not likely to adversely affect”
any threatened species of coral under the ESA, 50 C.F.R.
§ 402.13(a). Both the Corps and Service based their
conclusions on scientific literature; surveys showing that no
protected coral were present within 150 meters of the dredging
footprint; and plans to (1) conduct further surveys to determine
if and where coral was located along the disposal route, (2)
place turbidity-monitoring stations near any such coral, and (3)
use best practices to minimize any spilling of dredged material
during transport.

Appellants contend that the Corps’s NEPA analysis and
the Service’s ESA determination were arbitrary and capricious
because the agencies failed to consider the best available
science derived from a recent dredging project in Miami, and
the agencies improperly relied on uncertain mitigation
measures. In addition, Appellants argue that the Corps did not
gather adequate baseline data on the presence of coral, and that
 25
the Service changed its position on the project’s likely impact
on threatened corals without justification. We address each
argument in turn.

1. Best Available Science

Appellants claim that the Corps and the Service did not use
the “best scientific and commercial data available,” 16 U.S.C.
§ 1536(a)(2), in assessing the project’s detrimental effect on
corals. Specifically, Appellants assert that the agencies failed
to consider evidence from a recent dredging project in the Port
of Miami, which revealed negative impacts to corals that were
far away from the dredging site. But contrary to Appellants’
contentions, the Corps noted its consideration of the Miami
project at the time of the initial Environmental Assessment.
See J.A. 396 (“Based on conditions out there we will
implement lessons learned from Miami and follow up on what
the sensors indicate.”); id. at 913 (“The recently completed
project at Miami Harbor resulted in temporary effects to corals
associated with dredging, however those corals were located
immediately adjacent to the channel (within 30 meters), unlike
[San Juan Harbor] where dredging activities will not be directly
adjacent to the hardbottom areas that are located no less than
182 meters (600 feet) to the west of the channel.”). Moreover,
additional evidence from the Miami project came to light after
the Assessment was prepared. The agencies’ further analysis
based on that evidence noted that the two projects “are very
different,” and concluded that it was “extremely unlikely” that
the instant project would negatively affect corals in the way
that the Miami project did. Id. at 1168.6 Even if the agencies

6
We do not intend to suggest that a post-hoc rationalization could
make up for an inadequate initial explanation. See Regents of the
Univ. of Cal., 140 S. Ct. at 1909. We seek only to highlight that,
because the Miami project was completed just a few years prior to
 26
could have explained in more detail the “lessons learned from
Miami” at the outset, id. at 396, perfection is not required, and
the agencies adequately considered the available science and
data.

2. Uncertain Mitigation Measures

Next, Appellants attack the agencies’ reliance on a
monitoring plan and a promise to take action if turbidity levels
unexpectedly exceed projections. The monitoring plan
included in the Corps’s Environmental Assessment stated: “In
order to reduce the chances of turbidity and sedimentation
impacts to ESA-listed corals . . . from dredging and potential
leaks from disposal vessels, the [Corps] will work in
conjunction with the [Service] to develop a turbidity
monitoring plan.” J.A. 217. Though not every detail of the
plan was included in the Environmental Assessment, the Corps
provided the contours:

The plan will include turbidity monitoring
stations adjacent to ESA-listed corals (if any are
found during the pre-construction resource
surveys) and at the edges of the [habitat] for
elkhorn and staghorn corals near the disposal
vessel transit route. The exact number and
locations of the monitoring stations will be
determined and detailed in the collaborative

the Corps’s Environmental Assessment, not all scientific studies as
to the previous project’s impacts on corals had been completed when
the Corps began its environmental analysis. As the Corps learned
more, however, it properly responded. Cf. 40 C.F.R.
§ 1502.9(d)(1)(ii) (requiring supplemental environmental analysis if
“[t]here are significant new circumstances or information relevant to
environmental concerns and bearing on the proposed action or its
impacts”).
 27
monitoring plan. Turbidity in these locations
must not exceed 7 Nephelometric Turbidity
Units (NTUs) above background as measured at
the control locations positioned 200 meters (m)
upstream of the dredge. The monitoring plan
will include adaptive management measures to
be implemented to mitigate turbidity in the
event that turbidity exceeds 7 NTUs above
background at these locations. Adaptive
management may include measures to correct
disposal vessel leakage, reducing overflow, etc.

Id.; see also id. at 1186–87 (description of monitoring plan by
the Service).

Appellants challenge the turbidity-monitoring plan by
citing out-of-circuit cases that have rejected reliance on
undefined and unenforceable mitigation measures. See, e.g.,
Nat’l Parks & Conservation Ass’n v. Babbitt, 241 F.3d 722,
733–36 (9th Cir. 2001). But even if we assume, arguendo, that
the rule announced in those non-binding cases is correct, the
monitoring plan here is not undefined. It includes details, such
as the use of turbidity-monitoring stations, a specific threshold
at which adaptive management measures will be implemented,7
and the potential targets of those measures, depending on the
cause of any increased turbidity. Further, the Service indicated
that it would reinitiate consultation if the monitoring plan is not
in place or if turbidity persists above the established threshold.

7
Appellants take issue with the agencies’ selection of seven
turbidity units above background as the threshold. But, as
highlighted by the Service in explaining its determination, that
triggering threshold “is more conservative than the current EPA
standard of 29 NTUs over background or the Puerto Rico standard
of 10 NTU[s] over background for project related turbidity.” J.A.
1187.
 28
That level of specificity distinguishes the instant mitigation
measures from the ones discussed in the cases cited by
Appellants.

3. Baseline Data

Appellants next argue the Corps failed to conduct
sufficient baseline surveys before the project was approved to
determine whether corals were present in the mouth of the
Harbor, instead relying on a plan to conduct post-approval
surveys. Appellants likely forfeited this argument by not
raising it in their summary-judgment briefing below, but the
Corps has not argued that the issue is forfeited. See ECF No.
20-1 at 24–29 (Motion for Summary Judgment); Flynn v.
Comm’r, 269 F.3d 1064, 1068–69 (D.C. Cir. 2001); BNSF Ry.
Co. v. Surface Transp. Bd., 604 F.3d 602, 611 (D.C. Cir. 2010)
(“[A] forfeiture can be forfeited by failing on appeal to argue
an argument was forfeited.”). In any event, the argument fails
on its merits. The Corps looked at video surveys of the
dredging areas, which confirmed that no corals were present
within the footprint, as well as existing studies of habitats. And
the Corps explained the measures it would take to limit leakage
during the transportation of dredged materials if corals were
present along the transport route. The Corps additionally
planned to conduct post-approval surveys of other areas along
the vessel disposal routes to confirm the precise locations of
coral and to place turbidity-monitoring stations next to them.
That approach adequately considered the presence of corals.

4. Service’s Change in Position

Finally, Appellants note that the Service initially did not
concur with the Corps’s conclusion that corals were not likely
to be adversely affected by the dredging project and instead
requested further information. Appellants criticize the Service
for failing to explain its “flip-flop in position” when the Service
 29
subsequently agreed with the Corps’s assessment. Appellants
Br. 43 (citing FCC v. Fox TV Stations, Inc., 556 U.S. 502, 537
(2009)).

We disagree that there was a “policy change” for the
Service to acknowledge or explain: The Service’s preliminary
correspondence about the corals did not embody the sort of
authoritative agency policy or position that triggers the rule
prohibiting agencies from “ignor[ing] or countermand[ing]
[their] earlier factual findings without reasoned explanation for
doing so.” FCC v. Fox, 556 U.S. at 537. Moreover, the Corps
responded to the Service’s initial letter by providing additional
information, meeting with the Service to discuss the relevant
issues, and modifying its plan to monitor turbidity. The record
thus reflects that steps were taken to address the Service’s
concerns, and that its final decision to concur with the Corps
therefore was not arbitrary or capricious.

* * *

For the foregoing reasons, we affirm the judgment of the
district court.

So ordered.