Trout Unlimited v. Michelle Pirzadeh

FOR PUBLICATION

UNITED STATES COURT OF APPEALS
FOR THE NINTH CIRCUIT

TROUT UNLIMITED, No. 20-35504
Plaintiff-Appellant,
D.C. Nos.
and 3:19-cv-00265-SLG
3:19-cv-00267-SLG
BRISTOL BAY ECONOMIC 3:19-cv-00268-SLG
DEVELOPMENT CORPORATION;
BRISTOL BAY NATIVE
ASSOCIATION, INC.; UNITED OPINION
TRIBES OF BRISTOL BAY;
BRISTOL BAY REGIONAL
SEAFOOD DEVELOPMENT
ASSOCIATION, INC.; BRISTOL
BAY RESERVE ASSOCIATION;
SALMONSTATE; ALASKA
CENTER; ALASKA COMMUNITY
ACTION ON TOXICS; ALASKA
WILDERNESS LEAGUE; COOK
INLETKEEPER; DEFENDERS OF
WILDLIFE; EARTHWORKS;
FRIENDS OF MCNEIL RIVER;
NATIONAL PARKS
CONSERVATION ASSOCIATION;
NATIONAL WILDLIFE
FEDERATION; NATURAL
RESOURCES DEFENSE COUNCIL;
SIERRA CLUB; WILD SALMON
CENTER; MCNEIL RIVER
ALLIANCE,
Plaintiffs,
2 TROUT UNLIMITED V. PIRZADEH

v.

MICHELLE PIRZADEH, in her
official capacity as Acting
Regional Administrator of the
U.S. Environmental Protection
Agency, Region 10; MELISSA
HOFFER, in her official capacity
as Acting General Counsel for
EPA and delegated authority of
the Administrator; U.S.
ENVIRONMENTAL PROTECTION
AGENCY; MICHAEL S. REGAN, in
his official capacity as
Administrator, *
Defendants-Appellees,

STATE OF ALASKA,
Intervenor-Defendant-Appellee.

Appeal from the United States District Court
for the District of Alaska
Sharon L. Gleason, District Judge, Presiding

Argued and Submitted August 12, 2020
San Francisco, California

*
Pursuant to Federal Rule of Appellate Procedure 43(c)(2),
Michelle Pirzadeh is substituted for her predecessor as Acting Regional
Administrator of the U.S. Environmental Protection Agency, Region 10;
Melissa Hoffer is substituted for her predecessor as Acting General
Counsel for EPA; and Michael S. Regan is substituted for his
predecessor as Administrator.
 TROUT UNLIMITED V. PIRZADEH 3

Filed June 17, 2021

Before: Susan P. Graber and Daniel A. Bress, Circuit
Judges, and Robert T. Dawson, ** District Judge.

Opinion by Judge Graber;
Dissent by Judge Bress

SUMMARY ***

Environmental Law / Administrative Procedure Act

The panel affirmed in part, and reversed in part, the
district court’s dismissal of an action challenging the U.S.
Environmental Protection Agency (“EPA”)’s 2019
withdrawal of its 2014 proposed determination to exercise
its authority under Section 404(c) of the Clean Water Act to
restrict the ability of miners to operate in part of the Bristol
Bay watershed in southwestern Alaska.

The district court held the EPA’s decision was
unreviewable pursuant to 5 U.S.C. § 701(a)(2) of the
Administrative Procedure Act’s exception to reviewability,
and Heckler v. Chaney, 470 U.S. 821 (1985), because neither
the Clean Water Act nor the EPA’s regulations included a
meaningful legal standard governing the EPA’s decision.

**
The Honorable Robert T. Dawson, United States District Judge
for the Western District of Arkansas, sitting by designation.
***
This summary constitutes no part of the opinion of the court. It
has been prepared by court staff for the convenience of the reader.
4 TROUT UNLIMITED V. PIRZADEH

Reviewing de novo, the panel held that the Clean Water
Act contained no meaningful legal standard in its broad grant
of discretion to the EPA, but the EPA’s regulations
contained a meaningful legal standard. Specifically, to the
extent that plaintiff’s complaint challenged the EPA
Administrator’s failure to take action pursuant to the Clean
Water Act, without reference to the agency’s implementing
regulations, the panel held that it lacked jurisdiction.
Accordingly, the panel affirmed the district court’s dismissal
of plaintiff’s complaint insofar as the complaint rested
directly on the Clean Water Act. The panel held, however,
that 40 C.F.R. § 231.5(a) allowed the EPA to withdraw a
proposed determination only when an “unacceptable adverse
effect” on specified resources was not “likely.”
Accordingly, the decision was subject to judicial review
under the Administrative Procedure Act. The panel
remanded for further proceedings to determine whether the
EPA’s withdrawal was arbitrary, capricious, an abuse of
discretion, or contrary to law pursuant to 5 U.S.C.
§ 706(2)(A).

The panel rejected the EPA’s argument that the
withdrawal of the proposed determination here was best
characterized as an agency’s decision not to take
enforcement action that was presumptively unreviewable.

Dissenting, Judge Bress would hold that the agency’s
withdrawal from its discretionary exploratory process was
not subject to judicial review. Judge Bress wrote that the
majority opinion turned on a misreading of the governing
regulations, rewrote the rules that the EPA set for itself, and
inserted courts into what was supposed to be the preliminary
stages of a discretionary agency review process.
 TROUT UNLIMITED V. PIRZADEH 5

COUNSEL

Paul A. Werner III (argued), Steven P. Hollman, Abraham J.
Shanedling, and Kirsten O. Ryan, Sheppard Mullin Richter
& Hampton LLP, Washington, D.C., for Plaintiffs-
Appellant.

Anna T. Katselas (argued), Michael T. Gray, and Mark A.
Nitczynski, Attorneys; Eric Grant, Deputy Assistant
Attorney General; Environment and Natural Resources
Division, United States Department of Justice, Washington,
D.C.; Carrie Wehling and Heidi Nalven, Attorneys, United
States Environmental Protection Agency, Washington, D.C.;
for Defendants-Appellees.

OPINION

GRABER, Circuit Judge:

The Bristol Bay watershed in southwestern Alaska
contains considerable ecological and commercial resources.
One of the greatest wild salmon fisheries in the world,
Bristol Bay supports a diverse ecosystem, commercial
fishing operations, recreational fishing, and a subsistence
way of life for many tribal communities. The watershed also
holds rich mineral stores, attracting the attention of mining
companies. Competing interests have generated significant
controversy over the best uses of the watershed, but this
appeal stands apart from that debate; we decide only a single
legal issue concerning the reviewability of an agency’s
decision under the Administrative Procedure Act (“APA”).

In 2014, the Environmental Protection Agency (“EPA”)
formally proposed to exercise its authority under § 404(c) of
6 TROUT UNLIMITED V. PIRZADEH

the Clean Water Act to restrict the ability of miners to
operate in part of the watershed. Five years later, after
conducting nine public hearings and after receiving nearly
two million public comments, the EPA withdrew its
proposed determination by publishing an explanation in the
Federal Register as its final agency action. Plaintiff Trout
Unlimited then filed this action against Defendants EPA and
several EPA officials in their official capacities, challenging
the withdrawal of the EPA’s proposed determination as a
violation of both the Clean Water Act and the implementing
regulations.

Courts ordinarily may review final agency actions, but
Defendants moved to dismiss on the ground that the EPA’s
withdrawal fell within an exception to reviewability for
agency actions “committed to agency discretion by law,”
5 U.S.C. § 701(a)(2). The district court agreed with
Defendants, holding that the EPA’s decision was
unreviewable pursuant to 5 U.S.C. § 701(a)(2) and Heckler
v. Chaney, 470 U.S. 821 (1985). In the district court’s view,
neither the Clean Water Act nor the EPA’s regulations
include a meaningful legal standard governing the EPA’s
decision.

Reviewing de novo, City and County of San Francisco
v. U.S. Dept. of Transp., 796 F.3d 993, 998 (9th Cir. 2015),
we hold that (a) the Clean Water Act contains no meaningful
legal standard in its broad grant of discretion to the EPA but
that (b) the EPA’s regulations do contain a meaningful legal
standard. In particular, 40 C.F.R. § 231.5(a) allows the EPA
to withdraw a proposed determination only when an
“unacceptable adverse effect” on specified resources is not
“likely.” Accordingly, we affirm in part and reverse in part
the dismissal. We remand for further proceedings to
determine whether the EPA’s withdrawal was arbitrary,
 TROUT UNLIMITED V. PIRZADEH 7

capricious, an abuse of discretion, or contrary to law,
5 U.S.C. § 706(2)(A). We express no view on that question.

BACKGROUND

A. Section 404(c) of the Clean Water Act

The Clean Water Act generally prohibits the discharge
of dredged and fill materials into the waters of the United
States without a permit. 33 U.S.C. §§ 1311(a), 1344(a).
Section 404 of the Act governs “[p]ermits for dredged or fill
material” and assigns varying responsibilities to two
agencies: the U.S. Army Corps of Engineers and the EPA.
Id. § 1344. Generally speaking, the Corps administers the
§ 404 permitting program, 1 and the EPA uses its
environmental expertise to shape the contours of the
program. See, e.g., 44 Fed. Reg. 58076, 58081 (Oct. 9,
1979) (“While Congress had faith in the Corps’
administrative experience, it recognized EPA as the
‘environmental conscience’ of the Clean Water Act.”).

Section 404(a) provides that the Corps “may issue
permits . . . for the discharge of dredged or fill material into
the navigable waters at specified disposal sites.” Id.
§ 1344(a). Section 404(b), titled “[s]pecification for
disposal sites,” requires the Corps to “specif[y]” “each such
disposal site . . . for each such permit.” Id. § 1344(b). But
the Corps’ § 404(b) authority to specify disposal sites is
expressly “[s]ubject to subsection (c) of this section.” Id. In
turn, § 404(c) provides in full:

1
A State may also create its own permitting program under the Act,
which shifts many of the Act’s responsibilities to the State. 33 U.S.C.
§ 1344(g). Like most States, Alaska has chosen not to create its own
program, so our analysis focuses on the roles of the two federal agencies.
8 TROUT UNLIMITED V. PIRZADEH

The Administrator [of the EPA] is authorized
to prohibit the specification (including the
withdrawal of specification) of any defined
area as a disposal site, and he is authorized to
deny or restrict the use of any defined area for
specification (including the withdrawal of
specification) as a disposal site, whenever he
determines, after notice and opportunity for
public hearings, that the discharge of such
materials into such area will have an
unacceptable adverse effect on municipal
water supplies, shellfish beds and fishery
areas (including spawning and breeding
areas), wildlife, or recreational areas. Before
making such determination, the
Administrator shall consult with the
Secretary [of the Army]. The Administrator
shall set forth in writing and make public his
findings and his reasons for making any
determination under this subsection.

Id. § 1344(c).

Section 404(c) thus “authorize[s]” the Administrator of
the EPA to take action “whenever he determines” that the
discharge of dredged or fill material “will have an
unacceptable adverse effect” on environmental resources.
Id.; see 40 C.F.R. § 231.2(e) (defining “unacceptable
adverse effect” to encompass “significant degradation of
municipal water supplies . . . or significant loss of or damage
to” other resources). The Administrator may declare an area
off-limits entirely for a § 404 permit (“prohibit the
specification”); or, less drastically, he may “restrict the use”
of an area, thus limiting the scope of any allowable § 404
permit. Id.; 40 C.F.R. § 231.2(b)–(c); see 44 Fed. Reg. at
 TROUT UNLIMITED V. PIRZADEH 9

58076 (stating that the EPA could restrict the use of an area
by, for example, prohibiting a particular dredged or fill
material). The EPA has interpreted the statutory text to
allow it to act at any time: before a permit application has
been filed, while a permit application is pending, or even
after the Corps has issued a permit. 44 Fed. Reg. at 58076;
40 C.F.R. § 231.2(a)–(c); see also Mingo Logan Coal Co. v.
U.S. EPA, 714 F.3d 608, 612–16 & n.3 (D.C. Cir. 2013)
(holding that the statute’s use of the phrases “whenever” and
“including the withdrawal of specification” evince
Congress’ intent to allow the EPA to use its § 404(c)
authority after a permit issues). The EPA and others have
referred to the § 404(c) authority as a “veto.” E.g., 44 Fed.
Reg. at 58076, 58081; Mingo Logan, 714 F.3d at 613.

The statute requires “notice and opportunity for public
hearings,” and it requires the Administrator to issue a public,
written explanation for any § 404(c) determination.
33 U.S.C. § 1344(c). But the statute is silent on the
mechanics and details of those requirements.

B. Implementing Regulations

In 1979, the EPA promulgated extensive regulations that
govern the exercise of its § 404(c) authority. 40 C.F.R.
§§ 231.1–231.8. Because the regulations are important to
this appeal, we describe them in some detail.

The § 404(c) process starts with a “proposed
determination” by a Regional Administrator. Id.
§ 231.1(b)(1). “If the Regional Administrator has reason to
believe . . . that an ‘unacceptable adverse effect’ could result
from the specification or use for specification of a defined
area for the disposal of dredged or fill material, he may
initiate the following actions . . . .” Id. § 231.3(a). The
Regional Administrator first may notify the Corps’ District
10 TROUT UNLIMITED V. PIRZADEH

Engineer, the owner of the site, and any permit applicant of
the Regional Administrator’s intent to issue public notice of
“a proposed determination to prohibit or withdraw the
specification, or to deny, restrict or withdraw the use for
specification . . . of any defined area as a disposal site.” Id.
§ 231.3(a)(1). If the recipients persuade the Regional
Administrator that no adverse effect will result, then the
process ends. Id. § 231.3(a)(1)–(2). But if the recipients do
not “demonstrate[] to the satisfaction of the Regional
Administrator that no unacceptable adverse effect(s) will
occur . . . , the Regional Administrator shall publish notice
of a proposed determination in accordance with the
procedures of this section.” Id. § 231.3(a)(2).

“Every public notice shall contain, at a minimum,” seven
enumerated items describing the proposed determination
and other information pertaining to the site. Id. § 231.3(b).
The Regional Administrator must publish the notice in the
Federal Register and in a local newspaper, and the Regional
Administrator also must mail the notice to state and federal
agencies and to various persons, such as the owner of the site
and anyone who has subscribed to receive § 404(c) notices.
Id. § 231.3(d).

Publication of the notice begins a public comment
period, and “any interested persons may submit written
comments.” Id. § 231.4(a). “Comments should be directed
to whether the proposed determination should become the
final determination and corrective action that could be taken
to reduce the adverse impact of the discharge.” Id. The
Regional Administrator must consider the comments. Id.

The Regional Administrator “shall hold a public
hearing” in certain circumstances: “if an affected landowner
or permit applicant or holder requests a hearing,” if there is
a “significant degree of public interest” in a proposed
 TROUT UNLIMITED V. PIRZADEH 11

determination, or if “it would be otherwise in the public
interest to hold a hearing.” Id. § 231.4(b). If the Regional
Administrator holds a public hearing, he or she must issue
another public notice, containing all the original information
plus the details of the hearing. Id. §§ 231.3(c), 231.4(b). “A
record of the proceeding shall be made by either tape
recording or verbatim transcript.” Id. § 231.4(c). Anyone
may testify or submit written statements, and anyone may be
represented by counsel. Id. § 231.4(d). “The Regional
Administrator or his designee shall afford the participants an
opportunity for rebuttal.” Id. § 231.4(d). Persons may
submit written comments after the hearing to be included as
part of the hearing file. Id. § 231.4(f).

Publication of the notice of a proposed determination
also triggers a requirement that the EPA maintain an
administrative record. Id. § 231.4(g). The administrative
record “shall consist of” a range of documents, including all
public comments, the hearing file, the hearing transcript, any
record pertaining to the site maintained by the Corps, and
“[a]ny other information considered by the Regional
Administrator or his designee.” Id. § 231.5(e).

The Regional Administrator’s issuance of a proposed
determination also has an immediate effect on the Corps.
Once the Regional Administrator notifies the Corps of the
proposed determination, the Corps may not issue a permit
until the EPA concludes its § 404(c) process. 33 C.F.R.
§ 323.6(b); 40 C.F.R. § 231.3(a)(2). But “the Corps will
continue to complete the administrative processing of [any
permit] application while the section 404(c) procedures are
underway.” 33 C.F.R. § 323.6(b).
12 TROUT UNLIMITED V. PIRZADEH

Soon after the public-comment period ends,

[t]he Regional Administrator or his
designee shall . . . either withdraw the
proposed determination or prepare a
recommended determination to prohibit or
withdraw specification, or to deny, restrict, or
withdraw the use for specification, of the
disposal site because the discharge of
dredged or fill material at such site would be
likely to have an unacceptable adverse effect.

40 C.F.R. § 231.5(a).

If the Regional Administrator issues a recommended
determination, then he or she forwards the administrative
record for the Administrator’s review. Id. § 231.5(b). The
Administrator then makes “a final determination affirming,
modifying, or rescinding the recommended determination,”
after allowing the interested parties a final opportunity to
comment. Id. § 231.6. A final determination must be
published in the Federal Register (and elsewhere), and it
“constitutes final agency action.” Id. § 231.6.

If the Regional Administrator decides, instead, as
happened here, to withdraw the proposed determination,
then he or she notifies the Administrator. Id. § 231.5(c). The
Regional Administrator also must notify everyone who
previously commented, and those persons “may submit
timely written recommendations concerning review.” Id.
§ 231.5(c). The Administrator may decide to review the
withdrawal, which results in the same review process by the
Administrator described above. Id. § 231.5(c)(2).
Alternatively, the Administrator may accept the withdrawal
by declining to notify the Regional Administrator of an
intent to review the withdrawal. Id. § 231.5(c). “If the
 TROUT UNLIMITED V. PIRZADEH 13

Administrator does not notify him, the Regional
Administrator shall give notice [of] the withdrawal of the
proposed determination” by publishing the withdrawal in the
Federal Register (and elsewhere). Id. § 231.5(c)(1). “Such
notice shall constitute final agency action.” Id.
§ 231.5(c)(1).

The regulations generally prescribe short timeframes,
ranging from fifteen to sixty days, for each of the many
stages of the process. E.g., id. §§ 231.3(a)(2), 231.4(a),
231.5(a), 231.6. But the EPA recognized that the process
may take longer: The Administrator or the Regional
Administrator may extend the deadlines “upon a showing of
good cause.” Id. § 231.8. “Notice of any such extension
shall be published in the Federal Register and, as
appropriate, through other forms of notice.” Id.

The EPA has started the § 404(c) process only about a
dozen times in the half-century since the Clean Water Act’s
enactment. 79 Fed. Reg. 42314, 42317 (July 21, 2014)
(stating that it had “completed only 13 section 404(c)
actions” in the history of the Act). Nearly every time, the
EPA has issued a final determination that constrains the use
of the defined area in some way. Only twice has the EPA
decided to withdraw a proposed determination.

The first time that the EPA withdrew a proposed
determination was in 1991. The Regional Administrator had
proposed to restrict the site of a pending project to place
gravel on tundra wetlands. 56 Fed. Reg. 58247-01, 58247
(Nov. 18, 1991). As a result of the § 404(c) public process,
the project manager significantly revised the project, and the
Corps accommodated the change by approving a
modification of an existing permit. Id. The EPA then
concluded that the “revised project . . . represents a
significant reduction in scope and is environmentally
14 TROUT UNLIMITED V. PIRZADEH

acceptable to EPA.” Id. The EPA accordingly withdrew its
proposed determination and listed seven detailed reasons.
Id. For example, the revised project filled in fewer acres of
wetlands with gravel and thereby posed less of a threat to
species such as the tundra swan, brant, and caribou. Id.

The only other time that the EPA has withdrawn a
proposed determination concerns Bristol Bay and is the
subject of this appeal.

C. The Bristol Bay Watershed and Potential Mining

The Bristol Bay watershed encompasses a vast
geographical area in the southwestern corner of Alaska and
is home to 25 federally recognized tribes. The EPA has
described the watershed as “an area of unparalleled
ecological value, boasting salmon diversity and productivity
unrivaled anywhere in North America,” and as “one of the
greatest wild salmon fisheries left in the world.” 79 Fed.
Reg. at 42315–16. “The Bristol Bay watershed’s streams,
wetlands, and other aquatic resources support world-class,
economically important commercial and sport fisheries for
salmon and other fishes, as well as a more than 4,000-year-
old subsistence-based way of life for Alaska Natives.”
79 Fed. Reg. at 42315. “These salmon populations, in turn,
maintain the productivity of the entire ecosystem, including
numerous other fish and wildlife species.” Id.

The watershed also contains valuable minerals,
including copper, gold, and molybdenum, most densely
located in an area known as the Pebble deposit. Id. Since
the 1980s, mining companies have considered extracting
minerals from the watershed. In the first decade of the
2000s, Pebble Limited Partnership, Northern Dynasty
Minerals, Ltd., and their subsidiaries (collectively, “PLP”)
staked claims to minerals and began discussions with the
 TROUT UNLIMITED V. PIRZADEH 15

EPA, the Corps, and other agencies about obtaining the
permits needed to mine the Pebble deposit. In early 2011,
PLP submitted preliminary mining plans to the Securities
and Exchange Commission. The plans described three
stages of open-pit mining, with each stage encompassing an
ever-greater scope, ultimately extracting up to 12 billion tons
of ore.

Meanwhile, in 2010, nine tribal governments requested
that the EPA invoke its § 404(c) authority to protect the
watershed’s valuable natural resources from mining. The
EPA then received similar requests from additional tribes,
tribal organizations, commercial and recreational fishers,
seafood processors, chefs, restaurant and supermarket
owners, fishing and hunting guides, owners of sports fishing
and hunting lodges, sporting goods manufacturers and
vendors, a coalition of jewelry companies, conservation
organizations, members of the faith community, and elected
officials. Others requested that the EPA refrain from
invoking § 404(c): four tribal governments, other tribal
organizations, the governor of Alaska, and lawyers
representing PLP.

In early 2011, the EPA began a scientific study of the
potential effects of large-scale mining on the watershed and,
in January 2014, the effort culminated in the EPA’s
Watershed Assessment. The Watershed Assessment
considered the effects of mining from three different
scenarios, chosen from the preliminary plans that the PLP
had submitted to the Securities and Exchange Commission.
The Watershed Assessment described many risks to natural
and human resources posed by each scenario, including the
scenario with the smallest mine.
16 TROUT UNLIMITED V. PIRZADEH

D. Proposed Determination in 2014 and Withdrawal in
2019

In 2014, six months after completing the Watershed
Assessment, the EPA issued a proposed determination under
§ 404(c). 79 Fed. Reg. 42314. The Regional Administrator
of EPA’s Region 10 issued the proposed determination
“because of the high ecological and economic value of the
Bristol Bay watershed and the assessed unacceptable
environmental effects that would result from” mining the
Pebble deposit. Id. at 42315. The proposed determination
did not encompass the entire watershed and did not ban all
mining. Instead, the Regional Administrator proposed to
prohibit any mines within the geographical area of the
Pebble deposit that would result in any of the following
conditions: (1) the loss of five miles of streams with
documented salmon presence, or nineteen miles of
tributaries of those streams; (2) the loss of 1,100 or more
acres of wetlands, lakes, and ponds contiguous with salmon
streams or tributaries; or (3) streamflow alterations greater
than 20% of daily flow in nine miles of salmon streams. Id.
at 42317. The Regional Administrator calculated those
limits from the expected effects of the smallest mine
described in the PLP’s preliminary mining plans, the same
plans that the EPA had assessed in the 2014 Watershed
Assessment. Id.

The EPA’s consideration of the proposed determination
over the next five years had many twists and turns. See
84 Fed. Reg. 45749-01, 45749–50 (Aug. 30, 2019)
(describing the procedural history in some detail). We
describe only the points most salient to this appeal.

In 2014 and again in 2017, the EPA solicited public
comment. During the initial comment period, stemming
from publication of the proposed determination, the EPA
 TROUT UNLIMITED V. PIRZADEH 17

received more than 670,000 written comments, and more
than 800 people participated in seven separate hearings held
in the watershed and in Anchorage. 82 Fed. Reg. 33123-01,
33123 (Jul. 19, 2017). During the second comment period,
stemming from the EPA’s 2017 proposal to withdraw the
proposed determination, the EPA received more than a
million written comments, and about 200 people participated
in two additional hearings held in the watershed. 84 Fed.
Reg. at 45750.

In December 2017, PLP applied for a § 404 permit from
the Corps to mine the Pebble deposit. 84 Fed. Reg. at 45750.
According to the EPA, the proposed mine differs in several
respects from the assumptions that underlie the 2014
proposed determination. 84 Fed. Reg. at 45753. For
example, unlike PLP’s preliminary plans in 2011, the PLP
now plans to place a liner under a disposal facility, to use
less waste rock, and to extract minerals using methods other
than cyanide leaching. Id.

The permit application caused the Corps to begin
preparing an environmental impact statement and, at the
Corps’ invitation, the EPA became a “cooperating agency”
for purposes of developing the environmental impact
statement. 84 Fed. Reg. at 45750; see 40 C.F.R. § 1501.8
(describing the role of cooperating agencies). The permit
application also triggered certain procedural rights that the
EPA possesses pursuant to an existing memorandum of
agreement between the Corps and the EPA under § 404(q)
of the Clean Water Act, 33 U.S.C. § 1344(q). 84 Fed. Reg.
at 45752.

In August 2019, the EPA formally withdrew the
proposed determination in a detailed, eight-page public
notice. 84 Fed. Reg. 45749-01. Pointing to differences
between the PLP’s permit application in 2017 and the EPA’s
18 TROUT UNLIMITED V. PIRZADEH

assumptions in 2014, the EPA explained that the factual
basis for the 2014 proposed determination “has effectively
grown stale.” 84 Fed. Reg. at 45753. The EPA also
expressed confidence in its ability “to work constructively
with the Corps” pursuant to the procedures available to the
EPA both as a “cooperating agency” and as described in the
§ 404(q) memorandum of agreement—procedural
opportunities that were unavailable to the EPA in 2014.
84 Fed. Reg. at 45754–55. “If EPA believes that these
processes are not addressing its concerns, EPA retains the
discretion and the authority to . . . initiat[e] a new section
404(c) process that is informed by the entirety of the facts
and the Corps’ decision-making known to the Agency at that
time.” 84 Fed. Reg. at 45755.

E. This Action

In 2019, a few months after the EPA withdrew its
proposed determination, Plaintiff Trout Unlimited brought
this action. 2 Plaintiff describes itself as “the nation’s largest
sportsman’s organization dedicated to coldwater
conservation,” with hundreds of thousands of members
nationwide and more than 20,000 members and supporters
in Alaska. Plaintiff alleges that the EPA’s withdrawal of the
proposed determination was arbitrary, capricious, an abuse
of discretion, and contrary to law, in violation of the Clean

2
Other organizations also filed similar suits, and the district court
consolidated the cases. Plaintiff Trout Unlimited is the only appellant
before us, so we use the singular “Plaintiff.”

The State of Alaska intervened as a Defendant but took no position
on the reviewability of the EPA’s actions. On appeal, the State expressly
declined to file a brief and, instead, notified us that, “[i]n the event this
Court reverses, Alaska will renew its briefing on the merits before the
District Court on remand.”
 TROUT UNLIMITED V. PIRZADEH 19

Water Act, the EPA’s regulations, and the APA. Plaintiff
alleges, among other things, that political considerations
improperly motivated the EPA to abandon, without adequate
explanation, its many earlier scientific judgments that
mining in the watershed would have unacceptable effects.

The district court granted Defendants’ motion to dismiss.
The court concluded that the EPA’s withdrawal was
unreviewable because it was best characterized as a decision
not to take an enforcement action and because neither the
statute nor the regulations provide a meaningful legal
standard for the court to apply. Plaintiff timely appeals.

In July 2020, the Corps issued a final environmental
impact statement. 85 Fed. Reg. 44890-01. In November
2020, the Corps denied PLP’s permit application. Neither
the Corps’ denial of a permit nor any other reported action
by the relevant agencies has mooted this appeal, because an
order setting aside the agency’s withdrawal would have
effects beyond PLP’s specific permit application. See, e.g.,
“Corps of Engineers allows Pebble appeal for critical
permit,” The Cordova Times (Mar. 6, 2021), available at:
https://www.thecordovatimes.com/2021/03/06/corps-of-
engineers-allows-pebble-appeal-for-critical-permit/
(reporting that PLP’s administrative appeal of the permit
denial remains pending before the Corps); “E.P.A. to
Review Attacks on Science Under Trump,” The New York
Times (Mar. 24, 2021), available at:
https://www.nytimes.com/2021/03/24/climate/trump-science
-epa.html (reporting that the EPA plans to review the
agency’s past decisions, including decisions pertaining to
the Pebble mine, for improper political influence).
20 TROUT UNLIMITED V. PIRZADEH

DISCUSSION

The sole question before us is whether the EPA’s
withdrawal of its proposed determination is reviewable.

The APA generally authorizes courts to review a “final
agency action for which there is no other adequate remedy
in a court.” 5 U.S.C. § 704. The EPA’s publication of the
withdrawal in the Federal Register, following notice and
comment, marked “the consummation of the agency’s
decisionmaking process.” Bennett v. Spear, 520 U.S. 154,
178 (1997) (internal quotation marks omitted).
Additionally, “legal consequences . . . flow[ed]” from the
decision. Bennett, 520 U.S. at 178 (internal quotation marks
omitted). For example, the withdrawal meant that the Corps
no longer was barred from issuing a permit pertaining to the
Pebble deposit. 33 C.F.R. § 323.6(b); 40 C.F.R.
§ 231.3(a)(2). We therefore agree with the parties that the
EPA’s withdrawal of its proposed determination constituted
a “final agency action” for purposes of the APA. 3

Most—but not all—final agency actions are reviewable.
“The Administrative Procedure Act embodies a basic
presumption of judicial review and instructs reviewing
courts to set aside agency action that is ‘arbitrary, capricious,
an abuse of discretion, or otherwise not in accordance with
law,’ 5 U.S.C. § 706(2)(A).” Dep’t of Com. v. New York,

3
The EPA’s regulations specify that the publication of a withdrawal
of a proposed determination “shall constitute final agency action,”
40 C.F.R. § 231.5(c)(1), signaling that the agency considers the process
complete. But we, not the agency, are tasked with determining our own
jurisdiction under the APA, a statute that the EPA does not administer.
Accordingly, we do not accord the agency deference on questions of
reviewability under the APA. Dandino, Inc. v. U.S. Dept. of Transp.,
729 F.3d 917, 920 n.1 (9th Cir. 2013).
 TROUT UNLIMITED V. PIRZADEH 21

139 S. Ct. 2551, 2567 (2019) (citation and internal quotation
marks omitted). The “strong presumption that Congress
intends judicial review of administrative action . . . is
overcome only in two narrow circumstances.” ASSE Int’l,
Inc. v. Kerry, 803 F.3d 1059,1068 (9th Cir. 2015) (citations
and internal quotation marks omitted). The first exception,
which is not at issue here, applies “when Congress expressly
bars review by statute.” Pinnacle Armor, Inc. v. United
States, 648 F.3d 708, 718–19 (9th Cir. 2011) (citing 5 U.S.C.
§ 701(a)(1)). The second exception applies when “agency
action is committed to agency discretion by law.” 5 U.S.C.
§ 701(a)(2). Defendants argue that the EPA’s withdrawal of
the proposed determination falls within that second
exception.

The Supreme Court has “read the § 701(a)(2) exception
for action committed to agency discretion ‘quite narrowly.’”
Dep’t of Commerce, 139 S. Ct. at 2568 (citation omitted).
The APA expressly contemplates judicial review of an
agency’s ordinary discretionary judgments by authorizing
review of an agency’s action for “abuse of discretion.”
5 U.S.C. § 706(2)(A). The § 701(a)(2) exception therefore
applies only “if no judicially manageable standards are
available for judging how and when an agency should
exercise its discretion.” Heckler, 470 U.S. at 830. “Only
where there is truly no law to apply have we found an
absence of meaningful standards of review.” Perez Perez v.
Wolf, 943 F.3d 853, 861 (9th Cir. 2019) (internal quotation
marks omitted).

Below, we first consider whether (A) a judicially
manageable legal standard governs the agency’s exercise of
discretion. We then address Defendants’ alternative
argument that the agency’s withdrawal of the proposed
22 TROUT UNLIMITED V. PIRZADEH

determination is best characterized as (B) a decision not to
take enforcement action.

A. Judicially Manageable Legal Standard

“In order to assess whether the court has a meaningful
standard against which to judge the agency’s exercise of
discretion[,] we first look at the statute itself.” ASSE Int’l,
803 F.3d at 1069 (cleaned up). “[W]e consider ‘the language
of the statute and whether the general purposes of the statute
would be endangered by judicial review.’” Pinnacle,
648 F.3d at 719 (citation omitted).

But “the mere fact that a statute contains discretionary
language does not make agency action unreviewable.” Id.
(internal quotation marks omitted). “Even where statutory
language grants an agency unfettered discretion, its decision
may nonetheless be reviewed if regulations or agency
practice provide a meaningful standard by which this court
may review its exercise of discretion.” ASSE Int’l, 803 F.3d
at 1069 (internal quotation marks omitted). “[W]e ‘will find
jurisdiction to review allegations that an agency has abused
its discretion by exceeding its legal authority or by failing to
comply with its own regulations.’” Id. (quoting Abdelhamid
v. Ilchert, 774 F.2d 1447, 1450 (9th Cir. 1985)). In those
situations, the agency has chosen to constrain its own
discretion via regulations that carry the force of law. Id.
at 1070. So long as the regulations “provide a ‘meaningful
standard’ by which a court could review the [agency’s]
actions” and our review of the agency’s compliance with
those regulations does not “infring[e] any of the [agency’s]
prerogatives under the statute,” then we have jurisdiction,
pursuant to the APA, to review the agency’s compliance
with its own regulations. Id. at 1068–69; see also E.
Oakland-Fruitvale Plan. Council v. Rumsfeld, 471 F.2d 524,
534 (9th Cir. 1972) (“If a statute or regulation establishes a
 TROUT UNLIMITED V. PIRZADEH 23

rule governing the conduct of the agency with respect to an
aspect of the agency action, a court may determine whether
the agency has complied with that rule.”).

“[I]t is only in the context of [the plaintiff’s] complaint
that we can determine if there is law to be applied in the
instant case.” Perez Perez, 943 F.3d at 864 (internal
quotation marks omitted). Here, Plaintiff alleges that the
Regional Administrator’s withdrawal of the proposed
determination violated both (1) § 404(c) of the Clean Water
Act and (2) the agency’s implementing regulations. We
address each source of law in turn.

1. Section 404(c) of the Clean Water Act

Congress provided that “[t]he Administrator is
authorized” to restrict the specification “of any defined area
. . . as a disposal site, whenever he determines, after notice
and opportunity for public hearings, that the discharge of
such materials into such area will have an unacceptable
adverse effect” on specified resources. 33 U.S.C. § 1344(c)
(emphases added). The statute clearly conveys broad
discretion on the Administrator. The Administrator “is
authorized,” but not required, to restrict an area. See City
and County of San Francisco, 796 F.3d at 1002
(emphasizing that the statute’s use of permissive wording
“makes clear that [the agency’s decision] is discretionary”).
The statute grants authority to the Administrator “whenever
he determines” that adverse effects will result, not whenever
it can be shown that adverse effects will result. See Webster
v. Doe, 486 U.S. 592, 600 (1988) (holding that, because the
statute authorized the Director of the Central Intelligence
Agency to fire an employee “whenever the Director ‘shall
deem such termination necessary or advisable in the interests
of the United States’ (emphasis added), not simply when the
dismissal is necessary or advisable to those interests,” the
24 TROUT UNLIMITED V. PIRZADEH

statute “fairly exudes deference to the Director”). And the
number of “any defined [geographical] area[s]” is limitless,
suggesting that the agency retains discretion to choose
among areas of infinite variation. Cf. Ctr. for Pol’y Analysis
on Trade & Health v. Off. of the U.S. Trade Rep., 540 F.3d
940, 945–47 (9th Cir. 2008) (holding that a statutory
requirement that a trade group be “fairly balanced” was
unreviewable, in part because of the countless perspectives
and categories of potential representatives).

Nothing in the statute constrains the Administrator’s
discretion to initiate a public notice and comment period or,
ultimately, to decline to invoke his or her § 404(c)
authority. 4 The discretionary judgment as defined by the
statute likely “involve[s] balancing a number of
considerations, including availability and allocation of
agency resources, the predicted outcome of any
[investigation], and agency policies and priorities”—
considerations that ordinarily are beyond the scope of
judicial review. City and County of San Francisco, 796 F.3d
at 1002.

4
Of course, if the Administrator does choose to exercise discretion
by restricting the specification of a disposal site, the statute equally
plainly constrains that decision. The Administrator may exercise
§ 404(c) authority only when he or she has determined that a discharge
“will have an unacceptable adverse effect.” Id. Not surprisingly then,
courts have reviewed the Administrator’s exercise of § 404(c) authority.
E.g., Mingo Logan Coal, 714 F.3d at 609. But the fact that the agency’s
decision to exercise § 404(c) authority is governed by a judicially
manageable standard does not mean that the agency’s decision not to
exercise that authority necessarily is governed by the same standard. See
Bear Valley Mut. Water Co. v. Jewell, 790 F.3d 977, 989 (9th Cir. 2015)
(rejecting the argument that “if there is a manageable standard to review
an agency’s decision to exclude, . . . the same standard can, and should
be, used to review an agency’s decision not to exclude”).
 TROUT UNLIMITED V. PIRZADEH 25

Accordingly, we lack jurisdiction to review, for example,
a plaintiff’s challenge that the Administrator abused his or
her discretion by declining to initiate notice and comment
with respect to a particular geographical area or, as another
example, a plaintiff’s challenge that the Administrator
abused his or her discretion by declining to determine that
discharge into an area “will have an unacceptable adverse
effect” pursuant to the statute. The statute grants unfettered
discretion to the Administrator to make those decisions. And
given the practically limitless number of geographical areas
that the Administrator conceivably could consider,
subjecting each decision not to invoke § 404(c) could
overwhelm the agency’s resources and frustrate the statutory
purpose of protecting the nation’s waters. See 44 Fed. Reg.
at 58081 (declining to create a formal process for persons to
request that the Administrator invoke § 404(c) because, it
“might lead to the regional 404 staff being swamped with
requests”). We therefore agree with the majority of courts
that have held that plaintiffs may not bring statutory
challenges to the Administrator’s decision not to invoke
§ 404(c). See, e.g., Ctr. for Biological Diversity v. U.S. Army
Corps of Eng’rs, No. CV 14-1667 PSG (CWx), 2014 WL
12923196, at *6 (C.D. Cal. Sep. 26, 2014) (unpublished);
City of Olmstead Falls v. U.S. EPA, 266 F. Supp. 2d 718,
723 (N.D. Ohio 2003), aff’d 435 F.3d 632 (6th Cir. 2006);
Pres. Endangered Areas of Cobb’s Hist., Inc. v. U.S. Army
Corps of Eng’rs, 915 F. Supp. 378, 381 (N.D. Ga. 1995),
aff’d 87 F.3d 1242 (11th Cir. 1996); but see All. to Save the
Mattaponi v. U.S. Army Corps of Eng’rs, 515 F. Supp. 2d 1,
8 (D.D.C. 2007) (holding to the contrary after brief analysis).

To the extent that Plaintiff’s complaint challenges the
Administrator’s failure to take action pursuant to the statute,
without reference to the agency’s implementing regulations,
we lack jurisdiction over that challenge. Accordingly, we
26 TROUT UNLIMITED V. PIRZADEH

affirm the district court’s dismissal of Plaintiff’s complaint
insofar as the complaint rests directly on the Clean Water
Act.

B. Implementing Regulations

The statutory grant of unfettered discretion does not end
the analysis, though, because Plaintiff’s primary challenge is
that the EPA failed to comply with its own regulations. We
therefore assess whether the pertinent regulations have
constrained the agency’s discretion by supplying a
meaningful legal standard against which to measure the
agency’s action. ASSE Int’l, 803 F.3d at 1069–72.

Title 40 C.F.R. § 231.3 establishes the procedure for
issuing a proposed determination. If the Regional
Administrator has “reason to believe . . . that an
‘unacceptable adverse effect’ could result” from
specification, he or she “may initiate [two] actions:”
notifying various parties of the possibility of a proposed
determination and publishing notice of a proposed
determination, thereby triggering a public comment period.
40 C.F.R. § 231.3(a) (emphasis added).

Notably, 40 C.F.R. § 231.3 tracks the statute’s
permissive terminology. Nothing requires the Regional
Administrator to take any action with respect to a proposed
determination; instead, the Regional Administrator “may
initiate [the specified] actions.” Id. § 231.3(a) (emphasis
added). This step in the regulatory process thus retains the
agency’s unfettered discretion, and we find no meaningful
legal standard that constrains the Regional Administrator’s
determinations not to take action under § 231.3.

Once the Regional Administrator publishes notice of a
proposed determination, however, the regulations impose
 TROUT UNLIMITED V. PIRZADEH 27

mandatory procedural and substantive obligations. Public
notice of the proposed determination “shall be given,” id.
§ 231.3(b); the notice “shall contain” specified information,
id. § 231.3(b); the notice “shall . . . be published in the
Federal Register” and elsewhere, id. § 231.3(d); the agency
“shall . . . maintain[] the administrative record”, id.
§ 231.4(g); and the administrative record “shall consist” of
specified documents, id. § 231.5(e). “The Regional
Administrator shall provide a comment period,” and “[a]ll
. . . comments shall be considered.” Id. § 231.4(a). If the
Regional Administrator holds a public hearing, public notice
“shall be given,” id. § 231.4(b); the notice “shall contain”
specified information, id. § 231.3(b); the notice “shall . . . be
published in the Federal Register” and elsewhere, id.
§ 231.3(d); the hearings “shall be” recorded, id. § 231.4(c);
participants “shall” be afforded “an opportunity for
rebuttal,” id. § 231.4(d); and an additional comment period
“shall” be allowed following any hearing, id. § 231.4(f).

After the conclusion of the public comment period, any
public hearings, and any post-hearing comment periods, the
Regional Administrator or his designee “shall” decide
whether to withdraw the proposed determination or prepare
a recommended determination. Id. § 231.5(a). If the
Regional Administrator withdraws the proposed
determination, then he or she “shall notify” the
Administrator and all public commenters of the intent to
withdraw the proposed determination, and the public may
comment again, this time on whether the Administrator
should review the decision. Id. § 231.5(c). If the
Administrator declines to review the decision, the Regional
Administrator “shall give notice” of the withdrawal in the
Federal Register, and “[s]uch notice shall constitute final
agency action.” Id. § 231.5(c)(1).
28 TROUT UNLIMITED V. PIRZADEH

In this case, following the two public comment periods,
the Regional Administrator withdrew the proposed
determination pursuant to 40 C.F.R. § 231.5(a). The parties’
dispute hinges on the proper interpretation of that regulation.
Plaintiff reads the regulation as requiring the agency to
withdraw a proposed determination only if a legal standard
is met: if the discharge of materials is not “likely to have an
unacceptable adverse effect.” Id. The agency reads the
regulation as carrying forward the permissive, fully
discretionary regime of 40 C.F.R. § 231.3 that applies to the
creation of a proposed determination.

At the outset, we note that, when the EPA promulgated
the regulation in 1979, it could have chosen either system.
Had the EPA stated, for example, that the Regional
Administrator may withdraw a proposed determination for
any reason or no reason at all, then no meaningful legal
standard would apply; the decision would be unreviewable
under the APA; and our analysis would be at an end.
Similarly, had the EPA stated that the Regional
Administrator may withdraw a proposed determination only
if an unacceptable effect is unlikely, then a meaningful legal
standard would apply; the decision would be reviewable
under the APA; and our analysis of reviewability would be
at an end.

We must assess, of course, the wording that the EPA
actually chose, which is not entirely clear on the point. The
dissent’s thoughtful analysis presents one plausible
interpretation. On balance, however, we conclude that
Plaintiff’s reading has more support. As discussed below,
three factors support Plaintiff’s interpretation: the text of the
regulation, the structure of the regulations as a whole, and
the agency’s past practice. None of the factors is dispositive
by itself but, taken together, the factors lead us to conclude
 TROUT UNLIMITED V. PIRZADEH 29

that § 231.5(a) directs the Regional Administrator to
withdraw a proposed determination only if he or she
determines that an unacceptable adverse effect is not likely.

We begin with the text of the regulation:

The Regional Administrator or his designee
shall, [a specified number of days after the
expiration of the relevant comment period],
either withdraw the proposed determination
or prepare a recommended determination to
prohibit or withdraw specification, or to
deny, restrict, or withdraw the use for
specification, of the disposal site because the
discharge of dredged or fill material at such
site would be likely to have an unacceptable
adverse effect.

§ 231.5(a). Stripped to the essential aspects: The Regional
Administrator “shall . . . either withdraw the proposed
determination or prepare a recommended determination . . .
because the discharge of dredged or fill material at such site
would be likely to have an unacceptable adverse effect.” Id.

Read in isolation, a command that “a regulator shall
either do X or do Y because pollution levels are
unacceptable” implies that the regulator will do X only if
pollution levels are acceptable. The alternative
interpretation would allow the regulator to do X for any
reason at all, even if pollution levels are unacceptable. That
interpretation may be consistent with formal logic because
the regulator chose to do X—full stop. But the interpretation
strains how one ordinarily would understand a command of
that sort. See Synagogue v. United States, 482 F.3d 1058,
1061–62 (9th Cir. 2007) (“We begin with the text of the
statute, read in its context, and we give undefined terms their
30 TROUT UNLIMITED V. PIRZADEH

ordinary meanings.”); see also Mohamad v. Palestinian
Authority, 566 U.S. 449, 453 (2012) (declining to read a
phrase “unnaturally”). Similarly here, the text of the
regulation implies that the Regional Administrator will
withdraw a proposed determination only if an unacceptable
adverse effect is unlikely.

We emphasize that the inference is not absolute; the text
of the regulation, by itself, does not definitively answer the
question. For example, consider this hypothetical
regulation: “The official shall either reject the permit
application or issue the permit because the applicant meets
the qualifications.” Read in isolation, the sentence implies
that the rejection or issuance of the permit hinges on whether
the applicant meets the qualifications. But that inference
could be rebutted if, for example, the regulations elsewhere
specify a cap on the number of permits that may issue
regardless of an applicant’s qualifications. In that scenario,
if the cap had been reached, the official would comply with
the literal command of the quoted regulation by rejecting an
application despite the applicant’s qualifications. In short,
although a sentence of this form suggests one reading, the
proper interpretation of such a sentence depends on the
broader context of the regulation. Here, as we discuss in
detail below, the broader context confirms our reading of
40 C.F.R. § 231.5(a). 5

5
For that reason, we are unpersuaded by the dissent’s alternative
analogy about visiting a movie theater. The dissent’s analogy assumes
the wrong context by failing to take account of the fact that the relevant
command pertains to the end of a long process directed to gathering
pertinent information. Properly contextualized, a relevant analogy
would be to someone who has stood in line for 30 minutes wondering if
tickets remained for Citizen Kane. The directive would be: “Once
you’ve reached the ticket stand, you shall either go home or go to the
 TROUT UNLIMITED V. PIRZADEH 31

Here, the overall structure of the regulatory regime
confirms our interpretation. As described in detail above,
the regulations use broadly permissive wording when
describing the Regional Administrator’s actions concerning
whether to publish notice of a proposed determination. He
or she retains unfettered discretion—the Regional
Administrator “may initiate [certain] actions.” Id. § 231.3(a)
(emphasis added). But as soon as the Regional
Administrator decides to publish a notice of the proposed
determination, the regulations then require that the Regional
Administrator “shall” take many specific actions, including
a requirement to either withdraw the proposed determination
or issue a recommended determination. Id. § 231.5(a). Read
as a whole, then, the regulations strongly suggest that the
Regional Administrator’s unfettered discretion to act for any
reason whatsoever expires once, and only if, he or she
chooses to publish a proposed determination. See, e.g.,
Lopez v. Davis, 531 U.S. 230, 241 (2001) (holding that a
mandatory statutory command had a different meaning than
nearby permissive commands because “Congress’ use of the
permissive ‘may’ in [one subsection] contrasts with the
legislators’ use of a mandatory ‘shall’ in the very same
section”).

It is commonplace in the law for an actor’s choice to
undertake a wholly discretionary course of action to give rise
to a resulting non-discretionary duty that is governed by a
manageable legal standard. For example, a person has no
duty to undertake a rescue but, once a rescue is attempted,
the rescuer is held to a duty of care. See, e.g., Fowler V.
Harper, Fleming James, Jr. & Oscar S. Gray, Harper, James

movies because tickets remain for Citizen Kane.” You could literally
comply with the command by going home even if tickets are available
for Citizen Kane, but that is not what the speaker meant.
32 TROUT UNLIMITED V. PIRZADEH

and Gray on Torts §18.6 (3d ed. 2021) (“[T]he undertaking
to rescue, although not required, gives rise to the duty to
exercise care not to leave the object of the rescue in worse
condition than if the rescue had not been attempted.”);
Moloso v. Alaska, 644 P.2d 205, 212 (Alaska 1982) (“It is
ancient learning that one who assumes to act, even though
gratuitously, may thereby become subject to the duty of
acting carefully.” (internal quotation marks omitted)). The
same principle applies with equal force in the context of an
agency’s regulations. For example, in ASSE International,
803 F.3d at 1069–71, we held that, although the relevant
agency had full discretion to create—or not—exchange
visitor programs, the agency’s unfettered discretion ended
when it chose to create a program; the agency’s regulations
imposed mandatory, judicially reviewable duties on the
agency in the administration of an exchange program already
created.

We read the regulatory regime here to follow that same
pattern. The agency chose to retain full discretion (“may
initiate”) when deciding whether to start the regulatory
process, and it chose to constrain its discretion (“shall”) after
its decision to issue a proposed determination and to call for
public comments specifically on the likelihood of adverse
effects. 6

6
Defendants argue that a different regulation, 40 C.F.R. § 231.6,
supports their interpretation of § 231.5. Section 231.6 describes the
procedures that the Administrator must follow if he or she chooses to
review the Regional Administrator’s decision. In particular, § 231.6
requires the Administrator to “state the reasons for [his or her] final
determination.” Defendants urge us to conclude that, because § 231.5
does not contain a similar statement, the agency must have empowered
the Regional Administrator to act without any reason at all. We disagree.
Section 231.6 simply paraphrases the statutory text, which requires that
 TROUT UNLIMITED V. PIRZADEH 33

Finally, our interpretation is consistent with the agency’s
past practice. Cf. Mont. Wilderness Ass’n v. McAllister,
666 F.3d 549, 556–58 (9th Cir. 2011) (examining an
interpretation of a statute for consistency with the past
practice of relevant agencies). In the only previous
withdrawal of a proposed determination, concerning a
project to place gravel on tundra wetlands in 1991, the
Regional Administrator nowhere suggested that her
authority to withdraw could rest on anything other than a
conclusion that any effects were likely acceptable. 56 Fed.
Reg. at 58247. Instead, she explained:

Region 10 based initiation of 404(c)
proceedings on its belief that the project
could have unacceptable adverse impacts on
wildlife and wildlife habitat. The revised
project, however, represents a significant
reduction in scope and is environmentally
acceptable to EPA for the following [seven]
reasons [pertaining to effects on the
environment].

Id. (emphases added).

Because there is only one previous withdrawal of a
proposed determination, we readily acknowledge that this
factor does not weigh heavily in our analysis. But we also

“[t]he Administrator shall set forth . . . his reasons for making any
determination under this subsection.” 33 U.S.C. § 1344(c). Section
231.6 makes clear that the Administrator may not silently affirm the
Regional Administrator’s reasons for invoking § 404(c) but, instead, and
consistent with the statutory text, must provide his or her own reasons
for any final determination. The requirement that the Administrator
provide his or her own reasons does not imply that the Regional
Administrator may act without reason.
34 TROUT UNLIMITED V. PIRZADEH

do not consider past practice entirely irrelevant. The fact
that the agency’s previous withdrawal was due to its
reassessment of environmental effects supports our view that
the regulations contemplate precisely that inquiry.

For all of those reasons, we conclude that § 231.5(a)
allows the Regional Administrator to withdraw a proposed
determination only if the discharge of materials would be
unlikely to have an unacceptable adverse effect. The agency
has defined an “unacceptable adverse effect” to encompass
“significant” effects on specified resources. 40 C.F.R.
§ 231.2(e). That legal standard is akin to many other
standards that we regularly review under the APA. See, e.g.,
Bair v. Cal. Dept. of Transp., 982 F.3d 569, 577–81 (9th Cir.
2020) (reviewing, pursuant to the APA, an agency’s “finding
of no significant impact” under the National Environmental
Policy Act of 1969); Helping Hand Tools v. U.S. Env. Prot.
Agency, 848 F.3d 1185 (9th Cir. 2016) (reviewing, pursuant
to the APA, the EPA’s granting of a “prevention of
significant deterioration” permit under the Clean Air Act).

Nor does judicial review of the EPA’s compliance with
its own regulations threaten to “infring[e] any of the
[agency’s] prerogatives under the statute.” ASSE Int’l,
803 F.3d at 1069. The EPA remains free to consider—or
not—the suitability of invoking its § 404(c) authority with
respect to any given geographical area. Both the statute and
the first steps in the regulations, 40 C.F.R. § 231.3(a), grant
the agency unfettered discretion. But once the Regional
Administrator publishes a proposed determination and
triggers a public comment period, the agency must, under its
own regulations, decide what next step to take depending on
the likelihood of unacceptable effects. As noted above, the
number of potential geographical areas is effectively
limitless, and subjecting the EPA to judicial review with
 TROUT UNLIMITED V. PIRZADEH 35

respect to every conceivable area could overwhelm the
agency’s resources. By sharp contrast, the agency has
withdrawn a proposed determination after its discretionary
decision to initiate a period of public comment only twice in
a half-century. See 44 Fed. Reg. at 58079 (predicting,
accurately, that “EPA does not expect that the 404(c)
authority will be used very often”). Judicial review in those
rare instances, the frequency of which remains fully within
the agency’s control, poses no threat to the agency’s
statutory prerogatives.

In conclusion, even though the statute contains a broad
grant of discretion, the agency’s regulations contain a
meaningful legal standard governing the Regional
Administrator’s withdrawal of a proposed determination.
Accordingly, the decision is subject to judicial review under
the APA. See, e.g., ASSE Int’l, 803 F.3d at 1069 (holding
that, although the statute contains no meaningful standard
constraining the State Department’s discretion, the plaintiff
“has asked us to measure the State Department’s
administration of the [program] against the Department’s
own regulations. This we can do without infringing any of
the State Department’s prerogatives under the statute.”);
Alcaraz v. I.N.S., 384 F.3d 1150, 1161 (9th Cir. 2004)
(“While [the relevant statute], on its face, gives the Attorney
General discretion, the Alcarazes’ argument is that this
discretion has been legally circumscribed by various
memoranda through which the [agency] implemented its . . .
policy. Under these circumstances, we find that statute is
not drawn in such broad terms that there is no law to
apply.”); Mendez-Gutierrez v. Ashcroft, 340 F.3d 865, 868
(9th Cir. 2003) (holding that, even though “no statute or
regulation specifically govern[ed]” the petitioner’s
application to the agency, meaningful law nevertheless
existed because the application was “analogous, at least to
36 TROUT UNLIMITED V. PIRZADEH

some degree, to a motion to reopen, which is governed by a
clear set of rules and regulations”); see also County of
Esmeralda v. U.S. Dept. of Energy, 925 F.2d 1216, 1219 (9th
Cir. 1991) (holding that, although the statute provided no
express legal standard, we could review the agency’s
decision because, logically, “a judicially manageable
standard . . . readily presents itself,” and because we could
not “see how the purposes of the Act will be endangered by
judicial review of the type of action at issue here”). This
case thus differs from precedents in which neither the
relevant statute nor any regulation provided a meaningful
legal standard. See, e.g., Menominee Indian Tribe of Wis. v.
EPA, 947 F.3d 1065, 1072–73 (7th Cir. 2020) (holding, after
concluding that the statute contained no meaningful
standard, that the plaintiff “does not point to any regulations
governing the [agency’s decision]. We searched too and
came up empty, finding no statute, regulation, or guideline
[on point].”); City and County of San Francisco, 796 F.3d at
1002–03 (holding that the statute contained no meaningful
standard and not mentioning any pertinent regulation); Pac.
Gas & Elec. Co. v. FERC, 464 F.3d 861, 867 (9th Cir. 2006)
(same); Sierra Club v. Whitman, 268 F.3d 898, 902–05 (9th
Cir. 2001) (same); Alaska Fish & Wildlife Fed’n v. Dunkle,
829 F.2d 933, 938 (9th Cir. 1987) (same). Nor do we hold
that a permissive standard that applies to one type of decision
necessarily applies equally (and in reverse) to an opposite
decision, Bear Valley, 790 F.3d at 989; instead, we hold that
the agency intended the mandatory legal standard to apply
specifically and directly to decisions to withdraw a proposed
determination.

We hasten to add that the Regional Administrator retains
significant discretion—of the ordinary variety—when
making a determination under § 231.5(a). Reviewability
does not mean that the agency has no discretion at all. ASSE
 TROUT UNLIMITED V. PIRZADEH 37

Int’l, 803 F.3d at 1071. Whether “unacceptable” adverse
effects are “likely” is a flexible standard that draws
considerably on the agency’s expertise and judgment. Cf.
44 Fed. Reg. at 58078 (“[W]hat is required is a reasonable
likelihood that unacceptable adverse effects will occur—not
absolute certainty but more than mere guesswork.”). On
remand, the district court must accord “the proper
deference” to the agency’s decision on the merits when
applying the APA’s standards of review. ASSE Int’l,
803 F.3d at 1071.

We briefly offer several observations in response to the
dissent’s speculation of potential policy implications of our
decision. Dissent at 54–56. As an initial matter, we are
tasked with deciding the legal question before us: Is the
agency’s action reviewable? Policy implications play no
role in that analysis. Whatever the policy implications may
be from our decision, those implications do not influence
whether or not the agency’s withdrawal here is reviewable.

The dissent also appears to conflate reviewability with a
particular outcome. We repeat what we stated before:
nothing in our opinion affects whether the agency’s
withdrawal here violated the APA. In particular, nothing in
our decision speaks to the factors that are relevant when
assessing the likelihood of unacceptable effects. In cases in
which the agency acts after a permit has been issued and the
discharge of materials has begun, such as in Mingo Logan
Coal Co., 714 F.3d at 610–11, the likelihood of unacceptable
effects almost certainly hinges solely on a technical or
scientific judgment about the effects of the discharge. But
in cases in which the agency acts before a permit has been
issued, the likelihood of unacceptable effects also could
depend on the Regional Administrator’s prediction as to the
scope of any permit that the Corps would approve. That
38 TROUT UNLIMITED V. PIRZADEH

assessment, in turn, could rest on the EPA’s predicted ability
to influence the permitting process to avoid an unacceptable
effect, for example, because of procedural protections that
the Corps has afforded to the EPA. Nothing in our opinion
addresses whether the Regional Administrator must assess
stale technical data in the face of a revised permit
application, or whether he or she must disregard any
pertinent procedures that bind the relevant agencies. We
leave the merits determination solely for the district court’s
analysis on remand.

Finally, we are doubly puzzled by the dissent’s hand-
wringing about the agency’s being hamstrung by an earlier
action by that agency under a different administration.
Agencies take action all the time, for instance by issuing
final rules, that bind the agency for the future, regardless of
a change in philosophy or personnel. Moreover, our holding
that courts may review a withdrawal of a proposed
determination rests entirely on our interpretation of the
agency’s regulation. If the EPA disapproves of our
interpretation of § 231.5(a), it is free to change the rule
through ordinary rule-making. As noted above, if the
regulation granted unfettered discretion to the Regional
Administrator to withdraw a proposed determination, then
the decision would be unreviewable under the APA.

B. Decision Not to Take Enforcement Action

Defendants argue, in the alternative, that the withdrawal
of the proposed determination here is best characterized as
an agency’s decision not to take enforcement action. An
agency’s decision not to take enforcement action is
presumptively unreviewable, but that presumption may be
overcome if a meaningful legal standard constrains the
agency’s discretion. Heckler, 470 U.S. at 831–33. Because
we have concluded that the agency’s implementing
 TROUT UNLIMITED V. PIRZADEH 39

regulations clearly contain a meaningful legal standard,
regardless of the presumption of reviewability or
unreviewability, our decision does not turn on the proper
characterization of the agency’s action.

In any event, with respect to Plaintiff’s challenge to the
agency’s compliance with its regulations, the agency’s
decision is not properly characterized as a decision not to
take enforcement action. See City and County of San
Francisco, 796 F.3d at 1001–02 (summarizing the factors
that determine how to characterize an agency’s action). The
Regional Administrator must base his or her withdrawal
decision on the likelihood of unacceptable effects, not on
“allocation of resources” or on “agency policies and
priorities.” Id. at 1002. Unlike ordinary non-enforcement
actions, the agency’s withdrawal here has a real-world legal
effect of removing the prohibition on the Corps’ authority to
issue a permit. Id.; 33 C.F.R. § 323.6(b); 40 C.F.R.
§ 231.3(a)(2). Finally, withdrawal of a proposed
determination is not akin to the exercise of “prosecutorial
discretion, an arena in which courts have traditionally not
interfered.” City and County of San Francisco, 796 F.3d
at 1002. Unlike the private, discretion-laden charging
decisions made by a prosecutor, the EPA’s withdrawal of a
proposed determination is the culmination of reasoned,
public decisionmaking, following a formal period of public
comment and hearings.

AFFIRMED in part, REVERSED in part, AND
REMANDED. The parties shall bear their own costs on
appeal.
40 TROUT UNLIMITED V. PIRZADEH

BRESS, Circuit Judge, dissenting:

Sometimes there really is just no law to apply. In
administrative law, there is nothing for courts to do when
“agency action is committed to agency discretion by law.”
5 U.S.C. § 701(a)(2). That venerable principle should have
easily answered this case. Yet from a Clean Water Act
scheme that the majority concedes gives EPA unfettered
discretion, our court purports to discover a judicially
enforceable standard for reviewing EPA’s decision to
withdraw an initial exploratory determination—which is
itself merely an early-stage decision to cease pursuing a
purely discretionary enforcement mechanism.

The majority opinion turns on a serious misreading of the
governing regulations, rewriting the rules that EPA set for
itself and inserting courts into what was supposed to be the
preliminary stages of a discretionary agency review process.
Though the mine at the center of this case is a source of great
public controversy, the administrative law question here
should have been straightforward. The agency’s withdrawal
from its discretionary exploratory process is not subject to
judicial review. I thus respectfully dissent.

I

The Administrative Procedure Act, we all agree,
“embodies a ‘basic presumption of judicial review.’” Dep’t
of Com. v. New York, 139 S. Ct. 2551, 2567 (2019) (quoting
Abbott Laboratories v. Gardner, 387 U.S. 136, 140 (1967)).
But “[t]his is just a presumption.” Lincoln v. Vigil, 508 U.S.
182, 190 (1993) (quotations omitted). It is rebutted when
“agency action is committed to agency discretion by law.”
5 U.S.C. § 701(a)(2).
 TROUT UNLIMITED V. PIRZADEH 41

The classic example of such discretionary action is “an
agency’s decision not to institute enforcement proceedings.”
Lincoln, 508 U.S. at 191. That type of agency decision is in
fact “presumptively unreviewable.” Heckler v. Chaney,
470 U.S. 821, 832 (1985) (emphasis added). But more
broadly, § 701(a)(2) precludes judicial review “if no
judicially manageable standards are available for judging
how and when an agency should exercise its discretion.” Id.
at 830. In that situation, we lack jurisdiction to review the
agency’s decision. See, e.g., Alcaraz v. INS, 384 F.3d 1150,
1161 (9th Cir. 2004) (“Under the Administrative Procedure
Act, we lack jurisdiction to review agency actions that are
committed to agency discretion by law.” (quotations
omitted)).

No one doubts that § 701(a)(2) is a “narrow exception”
to our usual ability to review final agency actions. City &
County of S.F. v. U.S. Dep’t of Transp., 796 F.3d 993, 1002
(9th Cir. 2015) (quotations omitted). But nor is that
exception without import or content, either. There are
numerous cases in which the Supreme Court and our court
(to say nothing of other courts) have deemed agency action
unreviewable because it was committed to the agency’s
discretion. See, e.g., Lincoln, 508 U.S. at 184, 193; Webster
v. Doe, 486 U.S. 592, 600–01 (1988); Heckler, 470 U.S.
at 836–38; Int’l Bhd. of Teamsters v. U.S. Dep’t of Transp.,
861 F.3d 944, 953–54 (9th Cir. 2017); City & County of S.F.,
796 F.3d at 1002; Bldg. Indus. Ass’n of the Bay Area v. U.S.
Dep’t of Com., 792 F.3d 1027, 1035 (9th Cir. 2015); Bear
Valley Mut. Water Co. v. Jewell, 790 F.3d 977, 989–90 (9th
Cir. 2015); Ctr. for Policy Analysis on Trade & Health
(CPATH) v. Off. of U.S. Trade Representative, 540 F.3d 940,
946–47 (9th Cir. 2008), as amended (Oct. 8, 2008); Pac. Gas
& Elec. Co. v. FERC, 464 F.3d 861, 867 (9th Cir. 2006);
Sierra Club v. Whitman, 268 F.3d 898, 903–05 (9th Cir.
42 TROUT UNLIMITED V. PIRZADEH

2001); Helgeson v. Bureau of Indian Affs., Dep’t of Interior,
153 F.3d 1000, 1003 (9th Cir. 1998).

The case before us should have made a fine addition to
this string citation.

A

The Clean Water Act generally prohibits the discharge
of dredged or fill materials into navigable waters without a
permit. 33 U.S.C. §§ 1311(a), 1344(a). This case centers on
§ 404 of the Act, which concerns the permitting process. Id.
§ 1344. The Army Corps of Engineers is responsible for
issuing permits for specified disposal sites, known as
“specifications.” Id. § 1344(a)–(b), (d).

For our purposes, the key provision of the Act is
§ 404(c), which provides that the EPA Administrator “is
authorized” to prohibit, deny, or restrict a specification
“whenever he determines” that the discharge of materials
“will have an unacceptable adverse effect” on the water or
surrounding wildlife. Id. § 1344(c). The question presented
here is whether courts can review EPA’s decision to
withdraw a proposed determination to further explore using
its discretionary § 404(c) powers. The answer is clearly no.

My fine colleagues in the majority readily agree that
EPA’s decision to initiate the § 404(c) process is fully
discretionary, contains no meaningful legal standard, and is
therefore not subject to judicial review. That is entirely
correct given the statute’s permissive language. Indeed,
EPA’s decision not to proceed with a § 404(c) review looks
exactly like a traditionally unreviewable non-enforcement
decision. See Heckler, 470 U.S. at 832–33. It involves the
classic balancing of policy considerations—cost-benefit
analyses, agency priorities, and allocation of governmental
 TROUT UNLIMITED V. PIRZADEH 43

resources—that commonly exceed judicial review. See City
& County of S.F., 796 F.3d at 1001–02; Pacific Gas & Elec.,
464 F.3d at 867. The majority thus forthrightly “agree[s]
with the majority of courts that have held that plaintiffs may
not bring statutory challenges to the Administrator’s
decision not to invoke § 404(c).”

EPA’s implementing regulations unsurprisingly have the
same discretionary cast as the statute they serve. Under
40 C.F.R. § 231.3(a), “[i]f the Regional [EPA]
Administrator has reason to believe . . . that an ‘unacceptable
adverse effect’ could result from the specification” of a
disposal site, he “may initiate” certain sequential actions.
The Regional Administrator will notify interested parties
that he “intends to issue a public notice of a proposed
determination” to prohibit or restrict the specification. Id.
§ 231.3(a)(1) (emphasis added). And if within 15 days of
the notice “it has not been demonstrated to the satisfaction
of the Regional Administrator that no unacceptable adverse
effect(s) will occur,” or that corrective action will be taken,
the Regional Administrator “shall publish notice of a
proposed determination in accordance with the procedures
of this section.” Id. § 231.3(a)(2) (emphasis added).

A “proposed determination” merely reflects the initial
stage of a potential § 404(c) prohibition that EPA might
decide to issue later down the road, should the § 404(c)
process run its full course. As EPA explained in the
preamble to its § 404(c) regulations, “a proposed
determination does not represent a judgment that discharge
of dredged or fill material will result in unacceptable adverse
effects; it merely means that the Regional Administrator
believes that the issue should be explored.” Denial or
Restriction of Disposal Sites; Section 404(c) Procedures,
44 Fed. Reg. 58,076, 58,082 (Oct. 9, 1979).
44 TROUT UNLIMITED V. PIRZADEH

When it comes to initiating the “proposed
determination” process under the regulations, we thus again
find agency action committed to the agency’s discretion.
The majority concedes this same point. The majority
opinion recognizes that 40 C.F.R. § 231.3 “tracks the
statute’s permissive terminology,” so that “[t]his step in the
regulatory process thus retains the agency’s unfettered
discretion.” The majority then correctly concludes that there
is “no meaningful legal standard that constrains the Regional
Administrator’s determinations not to take action under
§ 231.3.” For the same reasons explained as to the statute
itself, § 231.3’s permissive language and the balancing of
agency priorities it reflects make the Regional
Administrator’s decision whether to proceed with a
proposed determination the very type of quasi-enforcement
decision that is committed to the agency’s discretion.

Once the Regional Administrator decides to publish
notice of a proposed determination, however, he must follow
certain procedures for public notice in 40 C.F.R. § 231.3(b)–
(d). He must also provide a public comment period and
permit comments “directed to whether the proposed
determination should become the final determination and
corrective action that could be taken to reduce the adverse
impact of the discharge.” Id. § 231.4(a). The regulations set
out further guidelines for when the Regional Administrator
should hold public hearings on the issue and the procedures
that govern those hearings. Id. § 231.4(b)–(g).

Once the public comment period has concluded, the
Regional Administrator must act within certain time frames
to either “withdraw” his proposed determination or to move
forward with preparing a “recommended determination” to
prohibit or limit the specification. Id. § 231.5(a). When the
decision is to withdraw the proposed determination, the
 TROUT UNLIMITED V. PIRZADEH 45

Regional Administrator must notify the EPA Administrator
(i.e., the Regional Administrator’s boss), who may decide to
review the withdrawal. Id. § 231.5(c)(2). If the Regional
Administrator withdraws the proposed recommendation and
the Administrator elects not to review it, the process ends.
Id. § 231.5(c)(1). If, however, the Regional Administrator
prepares a “recommended determination” to prohibit or limit
the specification, the Administrator must then review that.
Id. §§ 231.5(a)–(b), 231.6. That can, in turn, lead to a final
decision by the Administrator that prohibits or limits the
specification, id. § 231.6—the ultimate exercise of EPA’s
§ 404(c) power.

In the case before us, and before any permit application
for the Pebble Mine had even been submitted, the Regional
Administrator in 2014 issued a “proposed determination” on
the Pebble Mine and followed the required procedures for
public notice and comment. But in 2019, he then decided to
“withdraw” the proposed determination, concluding that
based on “the passage of time, the submittal of a permit
application, and a significant expansion of the record, [the
proposed determination] has effectively grown stale.”
84 Fed. Reg. 45,749, 45,753 (Aug. 30, 2019).

In particular, the Regional Administrator pointed to at
least six significant differences between the anticipated
mining proposal that EPA had evaluated in 2014 in issuing
its proposed determination, and the project’s then-current
proposal in 2019. Id. The Regional Administrator
determined that “it is more appropriate to use well-
established mechanisms to raise project-specific issues as
the record develops during the permitting process and
consider the full record before potential future decision-
making on this matter, instead of maintaining a section
404(c) process that is now five years old and does not
46 TROUT UNLIMITED V. PIRZADEH

account for the voluminous information provided in the
permitting process.” Id. Nevertheless, the Regional
Administrator reserved the right to initiate “a new section
404(c) process that is informed by the entirety of the facts
and the Corps’ decision-making known to the Agency.” Id.
at 45,755.

The EPA Administrator then declined to review the
withdrawal—which plaintiff Trout Unlimited now claims is
subject to judicial review.

B

One would have thought that in the context of purely
discretionary statutory authority to launch the § 404(c)
process and EPA implementing regulations that give the
Regional Administrator unreviewable discretion whether to
initiate the “proposed determination” exploratory
mechanism, a decision to withdraw a proposed
determination would also be committed to the agency’s
discretion. Alas, we learn today that is not true.

According to the majority, there is a judicially
manageable standard to review that action, which is
effectively a refusal to act. We are told that standard is to be
found in 40 C.F.R. § 231.5(a), which provides:

The Regional Administrator or his designee
shall [within specified time periods] . . .
either withdraw the proposed determination
or prepare a recommended determination to
prohibit or withdraw specification, or to
deny, restrict, or withdraw the use for
specification, of the disposal site because the
discharge of dredged or fill material at such
 TROUT UNLIMITED V. PIRZADEH 47

site would be likely to have an unacceptable
adverse effect.

Id. This provision indicates that the Regional Administrator
may move forward with a “recommended determination”
based on the finding that the discharge of material “would
be likely to have an unacceptable adverse effect.” Id. But
the majority concludes that a withdrawal of a proposed
determination nevertheless requires the Regional
Administrator to determine that a specification is not likely
to have an unacceptable adverse effect.

The majority’s twisted inversion of the regulation is
clearly wrong. The “unacceptable adverse effect” standard
applies if the Regional Administrator decides to prepare a
recommended determination to prohibit or restrict a
specification. The regulation makes clear that this is the only
permissible basis for taking such an action toward stopping
or limiting a specification—even as nothing in the regulation
requires the agency to take that action, either.

But the regulation obviously does not say, as the majority
nevertheless holds, that the Regional Administrator can only
withdraw a proposed determination based on the opposite
finding of “no unacceptable adverse effect.” The regulation
provides no standards whatsoever for such a decision to pull
back. And it thus places no judicially enforceable limits on
the Regional Administrator’s ability to withdraw. 5 U.S.C.
§ 701(a)(2); Heckler, 470 U.S. at 830. The majority has
invented a legal standard that does not exist in the statute or
regulations.

The majority’s analysis in reaching that result is deeply
flawed. The majority opinion reasons that “[a] command
that ‘a regulator shall either do X or do Y because pollution
levels are unacceptable’ implies that the regulator will do X
48 TROUT UNLIMITED V. PIRZADEH

only if pollution levels are acceptable.” This is a highly
precarious proposition on its face, and it finds no support in
language, logic, or law. In fact, we refused to credit a
substantially similar mirror image argument in Bear Valley
Mutual Water Co. v. Jewell, 790 F.3d 977 (9th Cir. 2015),
rejecting as “unavailing” the claim that “if there is a
manageable standard to review an agency’s decision to
exclude, . . . the same standard can, and should be, used to
review an agency’s decision not to exclude.” Id. at 989.

The majority’s stylized rendering of the regulation—”do
X or do Y because pollution levels are unacceptable”—also
fails to account for the nature of the agency decision before
us. The “X” here is a decision to pull back, i.e., to not
proceed with something. If I say, “you shall either not go to
the movies or go to the movies because Citizen Kane is
showing,” you would violate my directive if you went to the
movies to see Sunset Boulevard. But you may of course
decide not to go to the movies for any reason; I have placed
no limits on your discretion. Certainly, nothing about my
instructions would suggest you may not go to the movies
only if Citizen Kane is not showing. 1

1
The majority claims that the more “relevant analogy would be to
someone who has stood in line for 30 minutes wondering if tickets
remained for Citizen Kane,” so that, in its view, the more comparable
directive would be: “Once you’ve reached the ticket stand, you shall
either go home or go to the movies because tickets remain for Citizen
Kane.” This little debate underscores as much as anything how far the
majority has reimagined the regulatory text. The majority’s reworked
Citizen Kane hypothetical simply bakes in its conclusion, namely, that
the presumptive point of the proposed determination process is to move
forward with a recommended determination absent a particular finding.
Unlike the majority’s hypothetical of a moviegoer waiting in line—who
obviously has a dedicated objective of seeing the movie—the proposed
determination process is exploratory in nature and embodies no such
 TROUT UNLIMITED V. PIRZADEH 49

The majority asserts that my position, while concededly
“consistent with formal logic,” “strains how one ordinarily
would understand a command” like the one in 40 C.F.R.
§ 231.5(a). But I am at a loss to understand how the majority
can say this, as the language and logic work together.
Section 231.5(a) imposes a condition for the agency if it
wants to move forward, but no condition for stopping the
process. The Regional Administrator “shall . . . either
withdraw the proposed determination or prepare a
recommended determination because the discharge of
dredged or fill material at such site would be likely to have
an unacceptable adverse effect.” 40 C.F.R. § 231.5(a). This
certainly does not “impl[y],” as the majority holds, “that the
Regional Administrator will withdraw a proposed
determination only if an unacceptable adverse effect is
unlikely.” (Emphasis added.) That untenable interpretation
should be equally unpalatable to the logician and linguist
alike.

Of course, not even the majority is willing fully to
embrace its own inside-out theory of judicially manageable
standards, which would conflict with our decision in Bear
Valley. The majority thus quickly cautions that the inverted
inference it draws from the regulatory text “is not absolute”
because “the proper interpretation of such a sentence
depends on the broader context of the regulation.” I of
course agree we should interpret regulatory text in context.
But the context plainly supports the government.

foreordained objective. That explains why under the regulation as
written, no legal standard governs the agency’s ability to withdraw a
proposed determination, and why the agency need not initiate the
§ 404(c) process at all.
50 TROUT UNLIMITED V. PIRZADEH

As the majority itself holds, the decision to withdraw a
proposed determination takes place in the context of EPA’s
wholly discretionary (and thus unreviewable) decision to
initiate the § 404(c) process, and wholly discretionary (and,
again, unreviewable) decision to initiate the “proposed
determination” sub-process. Nothing about this overall
framework suggests that a decision to abandon an
exploratory first stage in the process should suddenly be
subject to judicial oversight. The majority implies it would
be a scandal if the Regional Administrator could withdraw a
proposed determination “for any reason at all.” But that
discretion is entirely consistent with what the majority
acknowledges is the “unfettered discretion” that otherwise
pervades the entire § 404(c) scheme.

Absent a judicially manageable standard, as here, a
decision to withdraw a proposed determination, no less than
a decision to initiate one, involves the “complicated
balancing of a number of factors which are peculiarly within
[the agency’s] expertise, such as allocation of resources and
agency policies and priorities.” City & County of S.F.,
796 F.3d at 1001–02 (quotations omitted). EPA’s
withdrawal decision in this case—which cited changed
circumstances, the ability to use other regulatory devices,
and a desire to reconsider the matter based on a more
accurate record, 84 Fed. Reg. 45,753–55—reflects typical
reasoning that agencies employ in setting prerogatives.

EPA’s withdrawal decision may have been lousy,
prudent, or somewhere in between. But there is no legal
standard in the statute or regulations by which to form that
judgment. See Menominee Indian Tribe of Wis. v. EPA,
947 F.3d 1065, 1073 (7th Cir. 2020) (concluding in the
context of a similar Clean Water Act scheme that “in the
absence of any regulation addressing the basis for the
 TROUT UNLIMITED V. PIRZADEH 51

decision to withdraw an objection, the choice is as
committed to the agency’s discretion as the decision to
object in the first instance”). It is a strange world indeed
when an agency’s withdrawal of an exploratory effort to
consider a purely discretionary enforcement decision turns
out to be agency action that is not “committed to agency
discretion by law.” 5 U.S.C. § 701(a)(2).

C

Given the overall scheme, it follows that the majority
errs in concluding that the “broader context of the
regulation” somehow supports its effort to wring from the
regulation a legal standard it does not contain. The majority
opinion reasons that “as soon as the Regional Administrator
decides to publish a notice of the proposed determination,
the regulations then require that the Regional Administrator
‘shall’ take many specific actions, including a requirement
to either withdraw the proposed determination or issue a
recommended determination.” From this the majority
deduces that “the regulations strongly suggest that the
Regional Administrator’s unfettered discretion to act for any
reason whatsoever expires once, and only if, he or she
chooses to publish a proposed determination.”

The majority’s conclusion does not follow. Once the
Regional Administrator publishes a notice of proposed
determination, there are indeed requirements that then apply.
See 40 C.F.R. §§ 231.3(b)–(d), 231.4. But those
requirements are entirely procedural (and there is no
suggestion that EPA here failed to follow them). That an
agency’s discretionary decision-making process is subject to
mandatory procedural rules says nothing about whether
there is a substantive, judicially manageable standard by
which to evaluate agency action.
52 TROUT UNLIMITED V. PIRZADEH

Indeed, we have never held that procedural requirements
have any necessary bearing on whether an agency’s
substantive decision is reviewable. In International
Brotherhood of Teamsters v. U.S. Dep’t of Transportation,
861 F.3d 944 (9th Cir. 2017), for example, the agency was
required to conduct a pilot program before issuing certain
long-haul trucking permits. Id. at 953. The pilot program
was subject to a slew of procedural requirements. Id. Yet
we held that the statute “provides ‘no meaningful standard
against which to judge the agency’s exercise of discretion’
in interpreting the data generated through the pilot program
and granting long-haul operating permits.” Id. at 954
(quoting Heckler, 470 U.S. at 830).

Citing no authority (I do not count the highly inapposite
discussion of the common law duty to rescue), the majority
has merely taken the entirely commonplace situation of
procedural rules that govern otherwise discretionary agency
decision-making, and then bootstrapped those rules into
support for a non-existent judicially manageable substantive
standard. The careful reader should thus not be taken in by
the majority’s discourse on the use of word “shall” in
40 C.F.R. § 231.5. The regulations use the word “shall” to
denote mandatory procedural obligations. “Shall” does no
more work than this. The requirement that the Regional
Administrator shall make a decision within a certain amount
of time says nothing about the basis by which he should
make that decision. 2

2
The majority therefore seriously errs in suggesting that ASSE Int’l,
Inc. v. Kerry, 803 F.3d 1059 (9th Cir. 2015), supports some broader
“principle,” apparently analogous to the common law duty to rescue,
under which a decision to undertake a discretionary action then
necessarily triggers a judicially manageable standard. In ASSE,
 TROUT UNLIMITED V. PIRZADEH 53

The majority makes a similar error of law in relying on
another contextual feature of the § 404(c) regulations, which
is that “the relevant command pertains to the end of a long
process directed to gathering pertinent information.” Once
again, the majority provides no legal support for the
suggestion that public comment periods or an information-
gathering process inform whether there exists a judicially
reviewable legal standard. As with procedural rules that
govern the timing of otherwise discretionary decisions,
public comment periods are ubiquitous in agency
regulations. But courts have routinely held that agency
action was committed to agency discretion notwithstanding
the substantial information-gathering processes that may
precede them. See, e.g., Ass’n of Irritated Residents v. EPA,
494 F.3d 1027, 1029, 1031–33 (D.C. Cir. 2007); Bear
Valley, 790 F.3d at 985, 989–90.

Finally, the majority errs in claiming that its
interpretation is “consistent with the agency’s past practice.”
The “past practice” referenced here is nothing of the sort, as
the majority effectively recognizes by “readily
acknowledg[ing] that this factor does not weigh heavily in
[its] analysis.” As the majority concedes, EPA has
withdrawn a proposed determination only one other time—

regulations permitted the agency to issue a sanctions order if it made one
of four substantive findings. Id. at 1071. The agency issued such an
order, and the aggrieved party challenged that decision. Id. ASSE was a
standard-issue decision in this area of administrative law. It is therefore
unsurprising that the regulations at issue in ASSE—which contained
defined legal standards—are in no way comparable to the regulations at
issue here, which lack any standard for the withdrawal of an exploratory
proposed determination. ASSE would be analogous if EPA issued a
§ 404(c) determination prohibiting a dredging project, see 33 U.S.C.
§ 1344; 40 C.F.R. § 231.6, and the regulated entity had challenged that
decision. But that is not this case.
54 TROUT UNLIMITED V. PIRZADEH

in 1991. And while in that case the Regional Administrator
determined that withdrawal was appropriate because the
reduced scope of the project mitigated the environmental
effects, the agency in that one instance certainly did not take
the position that a withdrawal could be justified only on that
basis. See 56 Fed. Reg. 58,247, 58,247 (Nov. 18, 1991).

So, we are left with this: an improper textual inference
that is “not absolute” plus past agency practice that “does not
weigh heavily in our analysis” plus “contextual” features
(like mandatory procedural rules) that commonly
accompany discretionary agency decision-making somehow
produce a legal standard capable of judicial review. That is
quite mistaken. There is nothing in the statute, regulations,
or past agency practice that creates a judicially manageable
standard for evaluating EPA’s decision to withdraw a
proposed determination under 40 C.F.R. § 231.5(a). In
concluding otherwise, the majority has imposed a legal
standard that neither Congress nor EPA saw fit to enact.

II

And to what end? The incentives that today’s decision
creates are troubling to say the least. Contrary to the evident
balance struck in the statute and implementing regulations,
the court’s decision today will vastly increase the costs of
EPA initiating the § 404(c) process. And that inevitable
consequence is likely, over time, to earn the disdain of those
on all sides of the push and pull between environmental
protection and commercial development.

We can imagine how this will play out. An EPA that is
more inclined toward environmental protection will now
find it strategically beneficial to more frequently initiate the
§ 404(c) proposed determination process. Doing so will
allow it to bind future EPAs that may be more favorable to
 TROUT UNLIMITED V. PIRZADEH 55

industry, and that, under today’s decision, will now need to
show a likelihood of “no adverse environmental effects” to
get out from under the proposed determinations of their
predecessors. 3

Conversely, an EPA that is more solicitous of
commercial development will now be less likely to initiate
the proposed determination process, when such a decision
cannot be as easily undone. Before today’s decision, such
an EPA might have found the proposed determination
process attractive because it could allow tentative
exploration, without commitment, into whether a
specification could cause undue environmental harm. An
EPA with that orientation could also use the proposed
determination device as leverage to achieve more limited
changes in a specification, without the “sledgehammer”
option of a full § 404(c) prohibition. But now the proposed
determination exploratory process comes with a serious
dilemma: it can only be withdrawn based on a finding of a
lack of environmental harm—a finding that, if EPA makes
it, is sure to tie the agency up in years of ancillary litigation.

This case proves that point. EPA issued its proposed
determination here in 2014. After many intervening events
and changes to the Pebble Mine proposal, EPA withdrew its
proposed determination in 2019. Now, in 2021, and after yet
further developments involving the mine project in the
nearly two years since, EPA is now told that its 2019
withdrawal was proper only if it could be explained on the
ground that the discharge of materials would be unlikely to

3
The majority notes that an agency can also bind its successors by
issuing final rules. But promulgating a final rule is a substantial, costly
undertaking, whereas issuing a notice of a proposed determination is an
exploratory action that can be initiated with far less cost and process.
56 TROUT UNLIMITED V. PIRZADEH

have an unacceptable adverse effect. A considerable amount
of agency and judicial resources have been (and will be)
devoted to what is ultimately EPA’s decision not to exercise
a discretionary power.

The majority’s confusing discussion of what the district
court and agency are supposed to do on remand only
compounds the problem. The majority maintains that
“nothing in our opinion affects whether the agency’s
withdrawal here violated the APA.” That statement is
difficult to comprehend when the EPA did not base its
withdrawal decision on the likelihood of no adverse
unacceptable adverse environmental effects, which is the
legal standard we are told applies here. To the extent the
majority is now suggesting that EPA could still consider
other factors (like “procedural protections”), the majority
has only muddied the legal standard it created. All that is
guaranteed here is further litigation over the meaning of
today’s decision and the obligations it imposes.

Those who wish to stop developments like the Pebble
Mine will no doubt applaud this result. But that constituency
will surely be displeased when an EPA less inclined toward
their views decides that initiating the otherwise discretionary
§ 404(c) process now comes at too great a price. The
majority’s opinion can thus only result in greater extremism
in environmental policy. Our political branches could of
course choose that path for themselves. But it was not for us
to impose it on them.

The agency withdrawal decision here was clearly agency
action “committed to agency discretion by law.” 5 U.S.C.
§ 701(a)(2). Our court errs in holding otherwise. I
respectfully dissent.