                                PUBLISHED

                 UNITED STATES COURT OF APPEALS
                     FOR THE FOURTH CIRCUIT


                                 No. 16-2432


MURRAY ENERGY CORPORATION; MURRAY AMERICAN ENERGY,
INC.; THE AMERICAN COAL COMPANY; AMERICAN ENERGY
CORPORATION; THE HARRISON COUNTY COAL COMPANY;
KENAMERICAN RESOURCES, INC.; THE MARION COUNTY COAL
COMPANY; THE MARSHALL COUNTY COAL COMPANY; THE
MONONGALIA COUNTY COAL COMPANY; OHIOAMERICAN ENERGY,
INC.; THE OHIO COUNTY COAL COMPANY; UTAHAMERICAN ENERGY,
INC.,

               Plaintiffs - Appellees,

         v.

ADMINISTRATOR OF ENVIRONMENTAL PROTECTION AGENCY,

               Defendant – Appellant,

         and

MON   VALLEY      CLEAN   AIR  COALITION; OHIO VALLEY
ENVIRONMENTAL     COALITION; KEEPER OF THE MOUNTAINS
FOUNDATION,

               Movants.


                                 No. 17-1093


MURRAY ENERGY CORPORATION; MURRAY AMERICAN ENERGY,
INC.; AMERICAN     COAL   COMPANY;   AMERICAN   ENERGY
CORPORATION; HARRISON COUNTY COAL COMPANY; KENAMERICAN
RESOURCES, INC.; MARION COUNTY COAL COMPANY; MARSHALL
COUNTY COAL COMPANY; MONONGALIA COUNTY COAL COMPANY;
OHIOAMERICAN ENERGY, INC.; OHIO COUNTY COAL COMPANY;
UTAHAMERICAN ENERGY, INC.,

                        Plaintiffs – Appellees,

                v.

THE   ADMINISTRATOR,                   UNITED         STATES   ENVIRONMENTAL
PROTECTION AGENCY,

                        Defendant – Appellee,

                v.

KEEPER OF THE MOUNTAINS FOUNDATION; MON VALLEY CLEAN AIR
COALITION; OHIO VALLEY ENVIRONMENTAL COALITION,

                        Movants – Appellants.

------------------------------------

CAUSE OF ACTION INSTITUTE; STATE OF WEST VIRGINIA; STATE OF
ARIZONA; STATE OF ARKANSAS; STATE OF GEORGIA; STATE OF
KANSAS; STATE OF LOUISIANA; STATE OF MICHIGAN; STATE OF
NEBRASKA; STATE OF NEVADA; STATE OF OHIO; STATE OF
OKLAHOMA; STATE OF SOUTH CAROLINA; STATE OF TEXAS; STATE
OF UTAH; STATE OF WISCONSIN; STATE OF WYOMING,

                        Amici Supporting Appellees.


                                          No. 17-1170


MURRAY ENERGY CORPORATION; MURRAY AMERICAN ENERGY,
INC.; AMERICAN     COAL    COMPANY;  AMERICAN   ENERGY
CORPORATION; HARRISON COUNTY COAL COMPANY; KENAMERICAN
RESOURCES, INC.; MARION COUNTY COAL COMPANY; MARSHALL
COUNTY COAL COMPANY; MONONGALIA COUNTY COAL COMPANY;
OHIOAMERICAN ENERGY, INC.; OHIO COUNTY COAL COMPANY;
UTAHAMERICAN ENERGY, INC.,

                        Plaintiffs – Appellees,

                                                  2
                v.

THE   ADMINISTRATOR,                 UNITED          STATES   ENVIRONMENTAL
PROTECTION AGENCY,

                        Defendant – Appellant,

                v.

MON VALLEY CLEAN AIR COALITION; KEEPER OF THE MOUNTAINS
FOUNDATION; OHIO VALLEY ENVIRONMENTAL COALITION,

                        Movants.

--------------------------------

CAUSE OF ACTION INSTITUTE; STATE OF WEST VIRGINIA; STATE OF
ARIZONA; STATE OF ARKANSAS; STATE OF GEORGIA; STATE OF
KANSAS; STATE OF LOUISIANA; STATE OF MICHIGAN; STATE OF
NEBRASKA; STATE OF NEVADA; STATE OF OHIO; STATE OF
OKLAHOMA; STATE OF SOUTH CAROLINA; STATE OF TEXAS; STATE
OF UTAH; STATE OF WISCONSIN; STATE OF WYOMING,

                        Amici Supporting Appellees.



Appeals from the United States District Court for the Northern District of West Virginia,
at Wheeling. John Preston Bailey, District Judge. (5:14-cv-00039-JPB)
                                 _______________

Argued: May 9, 2017                                             Decided: June 29, 2017
                                   Amended: July 18, 2017
                                    ________________

Before DIAZ, FLOYD, and THACKER, Circuit Judges.
                           _________________

Vacated in part and remanded with instructions; dismissed in part by published opinion.
Judge Floyd wrote the opinion, in which Judge Diaz and Judge Thacker joined.
                                  _________________



                                                 3
ARGUED: Matthew Littleton, UNITED STATES DEPARTMENT OF JUSTICE,
Washington, D.C.; William V. DePaulo, Charleston, West Virginia, for Appellants. John
Lazzaretti, SQUIRE PATTON BOGGS (US) LLP, Cleveland, Ohio, for Appellees. ON
BRIEF: Gautam Srinivasan, Matthew C. Marks, Air and Radiation Law Office, Office of
General Counsel, UNITED STATES ENVIRONMENTAL PROTECTION AGENCY,
Washington, D.C.; Jeffrey H. Wood, Acting Assistant Attorney General, Jennifer
Scheller Neumann, Patrick R. Jacobi, Richard Gladstein, Laura J.S. Brown, Sonya Shea,
Environment & Natural Resources Division, UNITED STATES DEPARTMENT OF
JUSTICE, Washington, D.C., for Appellant/Cross-Appellee United States Environmental
Protection Agency. Geoffrey K. Barnes, Robert D. Cheren, Danelle M. Gagliardi, Robert
B. McCaleb, SQUIRE PATTON BOGGS (US) LLP, Cleveland, Ohio, for Appellees.
Joshua N. Schopf, Eric R. Bolinder, CAUSE OF ACTION INSTITUTE, Washington,
D.C., for Amicus Cause of Action Institute. Patrick Morrisey, Attorney General, Elbert
Lin, Solicitor General, Erica N. Peterson, Assistant Attorney General, OFFICE OF THE
ATTORNEY GENERAL OF WEST VIRGINIA, Charleston, West Virginia, for Amici
State of West Virginia, State of Arizona, State of Arkansas, State of Georgia, State of
Kansas, State of Louisiana, State of Michigan, State of Nebraska, State of Nevada, State
of Ohio, State of Oklahoma, State of South Carolina, State of Texas, State of Utah, State
of Wisconsin, and State of Wyoming.




                                           4
FLOYD, Circuit Judge:

       In this case, we consider the bounds of a federal court’s authority under the Clean

Air Act (CAA) to correct an alleged failure by the U.S. Environmental Protection Agency

(EPA) to perform a non-discretionary, CAA-based act or duty.              See 42 U.S.C.

§ 7604(a)(2). The precise issue before us is whether this authority extends to review of

the EPA’s management of its continuous duty to evaluate the potential employment

impact of CAA administration and enforcement. See 42 U.S.C. § 7621(a). We hold that

it does not.


                                            I.

       In 1977, after extensive public debate about the effects of the CAA’s

environmental rules on employment, Congress enacted Section 321 of the CAA as a

mechanism for reviewing those effects. See H.R. Rep. No. 95-294, at 316–18 (1977),

reprinted in 1977 U.S.C.C.A.N. 1077, 1395–97.

       At issue in this case is Section 321(a) of the CAA, 42 U.S.C. § 7621(a), which

directs the EPA to continuously evaluate the potential employment impact of CAA

administration and enforcement. Section 321(a) provides:

       The [EPA] Administrator shall conduct continuing evaluations of potential
       loss or shifts of employment which may result from the administration or
       enforcement of the provision of this chapter and applicable implementation
       plans, including where appropriate, investigating threatened plant closures
       or reductions in employment allegedly resulting from such administration
       or enforcement.

42 U.S.C. § 7621(a).



                                            5
       In 2014, Murray Energy Corporation and related companies (collectively,

“Murray”) filed the instant suit against the EPA Administrator, alleging a failure to

comply with Section 321(a). Murray filed its suit under Section 304(a)(2) of the CAA,

42 U.S.C. § 7604(a)(2), which in pertinent part provides: “[A]ny person may commence

a civil action on his own behalf . . . against the [EPA] Administrator where there is

alleged a failure of the Administrator to perform any act or duty under [the CAA] which

is not discretionary with the Administrator.”     Murray’s suit requested an injunction

(1) ordering the EPA to conduct Section 321(a) evaluations; and (2) prohibiting the EPA

from engaging in certain regulatory activities until it had conducted such evaluations.

       At the outset of the litigation, the EPA moved to dismiss Murray’s suit on

jurisdictional grounds. The EPA first argued that its Section 321(a) duty was not a non-

discretionary duty cognizable under Section 304(a)(2). In a subsequent filing, the EPA

added that Murray lacked standing to challenge the EPA’s alleged non-compliance with

Section 321(a). The district court rejected both of the EPA’s jurisdictional arguments,

and declined to dismiss Murray’s suit at the pleading stage.

       Subsequently, the EPA moved for summary judgment and simultaneously

proffered fifty-three documents to prove the agency’s compliance with Section 321(a).

The EPA’s documents—which the agency conceded had not been prepared explicitly for

the purpose of Section 321(a) compliance—included regulatory impact analyses,

economic impact analyses, white papers, and other reports. The EPA asked the district

court to grant summary judgment in its favor on the basis of its proffer or, in the



                                             6
alternative, that the court grant summary judgment in Murray’s favor if it were to

conclude that the agency’s proffer was insufficient.

       Murray moved to hold in abeyance the EPA’s motion for summary judgment

pending the completion of discovery. The district court granted Murray’s motion, and

discovery continued. 1

       At the close of discovery, the EPA filed a renewed motion for summary judgment.

The EPA reiterated its position that Murray’s suit was not judicially cognizable and that,

even if it was, Murray lacked standing to bring its suit. Finally, the EPA renewed its

request for an up-or-down merits ruling that its proffer demonstrated compliance with

Section 321(a). In light of the continuous nature of the EPA’s duty under Section 321(a),

the EPA’s proffer at the renewed summary judgment stage increased from fifty-three to

sixty-four relevant documents.

       On October 17, 2016, the district court issued an opinion and order granting

summary judgment in Murray’s favor. Murray Energy Corp. v. McCarthy, No. 5:14-cv-

39, 2016 WL 6083946 (N.D.W. Va. Oct. 17, 2016) (“Summary Judgment Opinion”).


       1
         At one point during discovery, the district court refused to preclude a noticed
deposition of the EPA Administrator that was designed to address an alleged conflict
between the EPA’s litigation position that it had complied with Section 321(a) and prior
concessions by the EPA to Congress that it had not been conducting evaluations for the
purpose of Section 321(a) compliance. This Court, however, ultimately granted a writ of
mandamus precluding the noticed deposition. In re McCarthy, 636 F. App’x 142 (4th
Cir. 2015). We explained that the claim that the EPA had not prepared documents with
the intent of Section 321(a) compliance was not in conflict with the claim that the agency
had nonetheless prepared documents with the effect of Section 321(a) compliance, as
nothing in Section 321(a) conditions compliance on intent. Id. at 143–44.


                                            7
The court first held that Section 321(a) creates a non-discretionary duty that gives rise to

Section 304(a)(2) jurisdiction. The court then held that Murray possessed standing to

seek redress for alleged procedural, economic, and informational injuries.

       Finally, the court ruled in Murray’s favor on the merits. The court read Section

321(a) as obligating the EPA to assess the actual, site-specific employment effects of

CAA implementation. The court concluded that the EPA’s proffered documents did not

satisfy this requirement. In light of this conclusion, the court ordered the EPA to file a

“plan and schedule for compliance with [Section] 321(a) both generally and in the

specific area of the effects of its regulations on the coal industry.” Id. at *28.

       On October 31, 2016, the EPA submitted a response to the Summary Judgment

Opinion.       The EPA’s response opened with a set of objections to the court’s

jurisdictional, merits, and preliminary remedial rulings. Nonetheless, the EPA’s response

ultimately set forth a proposed plan and schedule to supplement its performance of

Section 321(a) evaluations. The EPA’s proposal drew sharp criticism from Murray.

       On December 14, 2016—before the district court had resolved the issue of an

appropriate remedy—Mon Valley Clean Air Coalition and related non-governmental

organizations (collectively, “Mon Valley”) filed a motion for leave to intervene in

support of the EPA. Specifically, Mon Valley claimed to have an interest in the EPA’s

regulatory activities under the CAA, and sought intervention under Federal Rule of Civil

Procedure 24 to prevent Section 321(a) from being used to stay or impede certain CAA

regulations.



                                               8
       On January 11, 2017, the district court issued an opinion and order outlining the

appropriate remedy. Murray Energy Corp. v. McCarthy, No. 5:14-cv-39, 2017 WL

150511 (N.D.W. Va. Jan. 11, 2017) (“Remedial Opinion”). In its opinion, the court

rejected the EPA’s proposed plan and schedule, and opted to craft its own remedy. The

court’s remedy was an extensive injunction ordering the EPA to conduct an evaluation

identifying, inter alia, facilities that are at risk of closure or reductions in employment

because of the EPA’s coal-related regulatory activities under the CAA, the past

employment ramifications of those activities, and the impact of CAA-related employment

losses and shifts on families and communities. Id. at *11.

       The court stopped short, however, of granting Murray complete relief.

Specifically, the court denied Murray’s request for an injunction staying the effective

date of certain pending CAA regulations and limiting the EPA’s authority to propose or

finalize new CAA regulations pending the agency’s compliance with Section 321(a).

The court reasoned that it lacked the authority to grant such relief in light of Section

321(d), 42 U.S.C. § 7621(d), which in pertinent part provides: “Nothing in [Section 321]

shall be construed to require or authorize the [EPA] Administrator . . . to modify or

withdraw any requirement imposed or proposed to be imposed under this chapter.” Id.

(quoting 42 U.S.C. § 7621(d)).

       On January 17, 2017, the district court issued an order denying as moot Mon

Valley’s motion to intervene, explaining that the court in its Remedial Opinion had

already denied the relief that Mon Valley opposed. Murray Energy Corp. v. McCarthy,

No. 5:14-cv-39 (N.D.W. Va. Jan. 17, 2017), J.A. 288–89 (“Intervention Order”). The

                                            9
court’s order also administratively closed the case, but noted that the court would

continue to supervise the implementation and enforcement of its injunction against the

EPA.

       The EPA noted timely appeals of the Summary Judgment Opinion, the Remedial

Opinion, and the Intervention Order. On appeal, the EPA challenges the district court’s

adverse jurisdictional, merits, and remedial rulings. 2 In addition, Mon Valley noted a

timely appeal of the Intervention Order. On appeal, Mon Valley challenges the district

court’s denial of the organization’s motion to intervene. We consolidated the EPA’s set

of appeals and Mon Valley’s appeal, and we examine each in turn.


                                            II.

       We begin by reviewing the district court’s conclusion that Section 304(a)(2)

authorizes Murray’s Section 321(a)-based suit against the EPA. Because this conclusion

implicates the subject matter jurisdiction of the federal courts, we review it de novo.

Lontz v. Tharp, 413 F.3d 435, 439 (4th Cir. 2005). We hold that the district court erred in

concluding that it could adjudicate Murray’s suit pursuant to Section 304(a)(2).

       Section 304(a)(2) authorizes suit to correct “a failure of the [EPA] Administrator

to perform any act or duty under [the CAA] which is not discretionary with the

Administrator.”    42 U.S.C. § 7604(a)(2).        We have construed Section 304(a)(2)

“narrowly” by confining its scope to the enforcement of legally required acts or duties of

       2
       Neither the EPA nor Murray contests the district court’s decision to partially
deny Murray injunctive relief.


                                            10
a specific and discrete nature that precludes broad agency discretion. Monongahela

Power Co. v. Reilly, 980 F.2d 272, 276 n.3 (4th Cir. 1992) (citing, inter alia, Envtl. Def.

Fund v. Thomas, 870 F.2d 892, 899 (2d Cir. 1989); Mountain States Legal Found. v.

Costle, 630 F.2d 754, 766 (10th Cir. 1980); Kennecott Copper Corp. v. Costle, 572 F.2d

1349, 1355 (9th Cir. 1978)).

       Our narrow construction reduces the risk of judicial disruption of complex agency

processes—a vice that Congress appeared intent on avoiding by writing a non-

discretionary requirement into the statute. See Kennecott, 572 F.2d at 1353 (explaining

that Section 304(a)(2)’s “legislative history reveals that Congress recognized the potential

for disruption of the administrative process inherent in a broad grant of jurisdiction,” and

inserted the non-discretionary requirement into the statute in order to minimize such

disruption (citing S. Comm. on Public Works, 93d Cong., 2d Sess., A Legislative History

of the Clean Air Amendments of 1970, Serial No. 93-18, Vol. 1 at 278 (1970))); accord

Nat. Res. Def. Council, Inc. v. Thomas, 885 F.2d 1067, 1073 (2d Cir. 1989).

       Moreover, our narrow construction gives Section 304(a)(2) a scope similar to that

of both the traditional mechanism for judicial review of agency operations, the writ of

mandamus, and the modern mechanism for judicial review of many types of agency

inaction, Section 706(1) of the Administrative Procedure Act (APA), 5 U.S.C. § 706(1).

See Norton v. S. Utah Wilderness All., 542 U.S. 55, 63–64 (2004) (describing mandamus

relief as “normally limited to enforcement of a specific, unequivocal command, the

ordering of a precise, definite act about which an official had no discretion whatever,”

and further explaining that “a claim under § 706(1) can proceed only where a plaintiff

                                            11
asserts that an agency failed to take a discrete agency action that it is required to take”)

(internal quotation marks, citations, and alterations omitted).

       With this understanding in mind, we turn to the question of whether Section

304(a)(2) authorizes suits to enforce the duty outlined in Section 321(a). As described

above, Section 321(a) provides that the EPA “shall conduct continuing evaluations of

potential loss or shifts of employment which may result from the administration or

enforcement of the provision of [the CAA] and applicable implementation plans,

including where appropriate, investigating threatened plant closures or reductions in

employment allegedly resulting from such administration or enforcement.” 42 U.S.C.

§ 7621(a). This statutory language, in our view, does not impose on the EPA a specific

and discrete duty amenable to Section 304(a)(2) review.

       Rather, Section 321(a)—when read as a whole—imposes on the EPA a broad,

open-ended statutory mandate. To begin, Section 321(a) calls for evaluations of the

potential employment impact of regulatory and enforcement activities—a duty which

demands the exercise of agency judgment. See Webster’s Third New Int’l Dictionary 786

(1976) (defining “evaluate” as “to examine and judge concerning the worth, quality,

significance, amount, degree, or condition of”).         Moreover, the relevant class of

regulatory and enforcement activities is extensive—it is the entire set of actions

administering and enforcing the CAA.         Finally, and perhaps most importantly, the

required evaluations are not confined to a discrete time period, but instead are to be

conducted on a continuing basis. Cf. Lujan v. Nat’l Wildlife Fed’n, 497 U.S. 871, 890

(1990) (refusing to treat a certain set of “continuing (and thus constantly changing)

                                             12
operations of the [Bureau of Land Management]” as an “agency action” reviewable under

the APA).

       The open-ended nature of Section 321(a)’s command is further confirmed by what

the statute does not say. Section 321(a) calls for evaluations without, for the most part,

specifying guidelines and procedures relevant to those evaluations. 3         Furthermore,

Section 321(a) establishes no start-dates, deadlines, or any other time-related instructions

to guide the EPA’s continuous evaluation efforts.

       The EPA is thus left with considerable discretion in managing its Section 321(a)

duty. The agency gets to decide how to collect a broad set of employment impact data,

how to judge and examine this extensive data, and how to manage these tasks on an

ongoing basis. A court is ill-equipped to supervise this continuous, complex process. Cf.

Vill. of Bald Head Island v. U.S. Army Corps of Eng’rs, 714 F.3d 186, 194 (4th Cir.

2013) (explaining, in an APA case, that “the obvious inability for a court to function in

such a day-to-day managerial role over agency operations” justifies “limit[ing] judicial

review to discrete agency action” (citing Norton, 542 U.S. at 62–64)).

       3
         The only detail of the evaluation duty that Section 321(a) provides is that the
duty includes “investigating threatened plant closures or reductions in employment
allegedly resulting from [CAA] administration or enforcement.” 42 U.S.C. § 7621(a).
However, Section 321(a) explicitly notes that these investigations need only be conducted
“where appropriate,” id., and thereby renders them a matter of agency discretion
unreviewable under Section 304(a)(2). See Guilford Cty. Cmty. Action Program, Inc. v.
Wilson, 348 F. Supp. 2d 548, 556 (M.D.N.C. 2004) (holding that a statute providing that
a state “shall” offer training and assistance “if appropriate” leaves the state with
“discretion in providing training and assistance”); cf. Michigan v. EPA, 135 S. Ct. 2699,
2707 (2015) (explaining that “‘appropriate’ is the classic broad and all-encompassing
term”—one that “leaves agencies with flexibility”) (internal quotation marks omitted).


                                            13
       On a final note, we add that Section 321(a)’s poor fit for judicial review is

underscored when the statute is viewed alongside other CAA provisions that offer

discrete directives accompanied by specific guidance on matters of content, procedure,

and timing. For example, the very next provision, Section 321(b), 42 U.S.C. § 7621(b),

directs the EPA to investigate an employee’s claim that an actual or proposed CAA

requirement adversely affected his or her employment, and establishes a framework for

related public hearings, reports, and findings of fact. Meanwhile, Section 317, 42 U.S.C.

§ 7617, directs the EPA to prepare economic impact assessments for enumerated agency

actions, and outlines deadlines, procedural details, and specific factors for analysis.

Section 321(a) fails to offer such clear instructions that could serve as a solid basis for

judicial review.

       Accordingly, we hold that Section 304(a)(2) does not authorize the instant suit by

Murray against the EPA, and that the district court thus lacked jurisdiction over the suit. 4

Consequently, we vacate the district court’s judgments insofar as they impact the EPA,

and remand this matter to the district court with instructions that it dismiss Murray’s suit

for want of jurisdiction. See Steel Co v. Citizens for a Better Env’t, 523 U.S. 83, 94, 101

       4
          Murray briefly suggests that—setting aside Section 304(a)(2) of the CAA—
jurisdiction may be conferred to the district court in this case by the APA, see 5 U.S.C.
§ 702 et seq., or by the mandamus statute, see 28 U.S.C. § 1361. Assuming arguendo
that the APA or the mandamus statute could ever authorize judicial review of the EPA’s
compliance with the CAA, we conclude that those provisions do not do so in this case.
As explained above, those provisions only empower a court to respond to an agency’s
failure to act in the face of a clear-cut duty, see Norton, 542 U.S. at 63–64; they do not
empower a court to supervise an agency’s compliance with a broad statutory mandate of
the sort contained in Section 321(a), see id. at 66–67.


                                             14
(1998) (“Without jurisdiction the court cannot proceed at all in any cause. Jurisdiction is

power to declare the law, and when it ceases to exist, the only function remaining to the

court is that of announcing the fact and dismissing the cause.” (quoting Ex parte

McCardle, 74 U.S. (7 Wall.) 506, 514 (1868))). In light of this disposition, we decline to

address the EPA’s challenges to the district court’s standing, merits, and remedial

rulings. 5


                                            III.

        We next turn to Mon Valley’s appeal of the district court’s denial of its motion to

intervene. We conclude that this appeal is moot, and must therefore be dismissed.

        “A case becomes moot, and thus deprives federal courts of subject matter

jurisdiction, ‘when the issues presented are no longer ‘live’ or the parties lack a legally

cognizable interest in the outcome.’” Pashby v. Delia, 709 F.3d 307, 316 (4th Cir. 2013)

(quoting Simmons v. United Mortg. & Loan Inv. LLC, 634 F.3d 754, 763 (4th Cir. 2011)).

We have recently described the circumstances in which an appeal of a denial of a motion

to intervene is not rendered moot by the dismissal of the underlying action: “[W]e can

provide an effective remedy on appeal and therefore have jurisdiction” only “[1] when


        5
        We note one additional point. In its appellate briefing, Murray claims that the
EPA’s alleged dereliction of its Section 321(a) duty constitutes “agency action
unreasonably delayed” that is actionable under Section 304(a) of the CAA, 42 U.S.C.
§ 7604(a). We decline to consider this claim because Murray failed to plead it in its
complaint. See S. Walk at Broadlands Homeowners Ass’n, Inc. v. OpenBand at
Broadlands, LLC, 713 F.3d 175, 184 (4th Cir. 2013) (“It is well-established that parties
cannot amend their complaint through briefing.”).


                                            15
the motion to intervene is made while the controversy is live and [2] the subsequent

disposition of the case does not provide the relief sought by the would-be intervenors”

and does not preclude us from granting said relief. CVLR Performance Horses, Inc. v.

Wynne, 792 F.3d 469, 475 (4th Cir. 2015).

       Assuming arguendo that Mon Valley has satisfied the first condition for

jurisdiction, its appeal nonetheless falters on the second condition. Mon Valley sought to

intervene in this case to help the EPA resist Murray’s request for an injunction restricting

the EPA’s regulatory authority under the CAA pending the agency’s compliance with

Section 321(a). However, our holding that the EPA’s compliance with Section 321(a) is

not judicially reviewable under Murray’s jurisdictional theories—plus our resulting

remand for dismissal of Murray’s suit—forecloses the possibility that the district court

could issue the above-described injunction.       Our disposition of this case therefore

provides Mon Valley all of the relief it was seeking through intervention, and leaves us

with no basis to entertain the organization’s appeal of the denial of its motion to

intervene. As such, that appeal must be dismissed as moot. 6




       6
          For the first time on appeal, Mon Valley argues that it has an interest in
influencing the content of the evaluations that the district court ordered the EPA to
conduct. Even if we assume that this belated argument is properly before us, it still does
not alter our conclusion that Mon Valley’s appeal is moot. Because we are vacating the
district court’s orders against the EPA and remanding for dismissal of Murray’s suit,
there are no longer any valid court-ordered evaluations that we can authorize Mon Valley
to participate in. In other words, our disposition of this case precludes us from granting
Mon Valley the remedy that it seeks.


                                            16
                                           IV.

       For the foregoing reasons, we vacate the district court’s judgments insofar as they

impact the EPA, and remand with instructions to have Murray’s suit dismissed for want

of jurisdiction. We also dismiss as moot Mon Valley’s appeal of the denial of its motion

to intervene.

                                                          VACATED IN PART AND
                                                   REMANDED WITH INSTRUCTIONS;
                                                             DISMISSED IN PART




                                           17
