In the

    United States Court of Appeals
                  For the Seventh Circuit
                      ____________________
No. 18-3644
PRAIRIE RIVERS NETWORK,
                                                   Plaintiff-Appellant,
                                   v.

DYNEGY MIDWEST GENERATION, LLC,
                                                  Defendant-Appellee.
                      ____________________

              Appeal from the United States District Court
                   for the Central District of Illinois.
               No. 2:18-cv-02148 — Colin S. Bruce, Judge.
                      ____________________

   DECIDED SEPTEMBER 24, 2020 – PUBLISHED OCTOBER 2, 2020
                    ____________________
    SCUDDER, Circuit Judge, in chambers. Many Q&As with ap-
pellate judges draw a question whether amicus curiae briefs
add value to deciding cases. And most of the time judges give
the answer that first-year law students quickly learn is ubiq-
uitous in the law—“sometimes; it depends.” This opinion of-
fers a few thoughts on the question as part of explaining why
I granted motions to accept three amicus briefs in this appeal.
   Prairie Rivers Network appeals the dismissal of the suit it
brought under the Clean Water Act against Dynegy Midwest
Generation, the owner of a power station in Vermillion,
2                                                     No. 18-3644

Illinois. The Network alleged that Dynegy’s station was re-
leasing contaminants into groundwater, but the district court
dismissed the suit concluding that the Clean Water Act does
not regulate groundwater. Much of the appeal focuses on
whether the district court’s analysis of the Clean Water Act,
and its application (or lack thereof) to the alleged groundwa-
ter contamination, remains valid after the Supreme Court’s
recent decision in County of Maui v. Hawaii Wildlife Fund, 

(2020).
    Three organizations have sought permission to file friend-
of-the-court briefs in support of Dynegy’s position on appeal.
The Network opposes these motions, asserting that each brief
does nothing more than parrot Dynegy’s arguments and
waste the court’s time.
     The guidance for prospective amici is sparing. The Federal
Rules of Appellate Procedure say only that a prospective
friend of the court must explain “why an amicus brief is de-
sirable and why the matters asserted are relevant to the dis-
position of the case.” FED. R. APP. P. 29(a)(3)(B). Our Practi-
tioner’s Handbook for Appeals adds that, in deciding whether to
accept an amicus brief, the court looks at whether the submis-
sion “will assist the judges by presenting ideas, arguments,
theories, insights, facts, or data that are not found in the briefs
of the parties.” See Practitionerʹs Handbook for Appeals to the
United States Court of Appeals for the Seventh Circuit, XXII.B
“Amicus Briefs” (2020 ed.) (citing Voices for Choices v. Illinois
Bell Telephone Co., 

, 544–45 (7th Cir. 2003) (Posner,
J., in chambers)).
    At times individual judges have rightly observed that too
many amicus briefs do not even pretend to offer value and in-
stead merely repeat (literally or through conspicuous
No. 18-3644                                                    3

paraphrasing) a party’s position. See, e.g., Voices for 

(“[I]t is very rare for an amicus curiae brief to
do more than repeat in somewhat different language the ar-
guments in the brief of the party whom the amicus is support-
ing.”); Ryan v. CFTC, 

, 1063 (7th Cir. 1997) (Pos-
ner, C.J., in chambers) (“[T]he vast majority of [amicus curiae
briefs] have not assisted the judges . . . .”). Nobody benefits
from a copycat amicus brief and indeed our practice is to reject
them. See Natʹl Org. for Women, Inc. v. Scheidler, 

,
617 (7th Cir. 2000). Nor should amicus briefs serve only as a
show of hands on what interest groups are rooting for what
outcome. See Sierra Club, Inc. v. E.P.A., 

, 518 (7th
Cir. 2004) (“Courts value submissions not to see how the in-
terest groups line up, but to learn about facts and legal per-
spectives that the litigants have not adequately developed.”).
    Rather, a true friend of the court will seek to add value to
our evaluation of the issues presented on appeal. To be sure,
the fiction that an amicus acts as a neutral information broker,
and not an advocate, is long gone. See Samuel Krislov, The
Amicus Curiae Brief: From Friendship to Advocacy, 72 YALE L.J.
694, 703–04 (1963). But even a friend of the court interested in
a particular outcome can contribute in clear and distinct ways,
by, for example:
       Offering a different analytical approach to the legal is-
        sues before the court;
       Highlighting factual, historical, or legal nuance
        glossed over by the parties;
       Explaining the broader regulatory or commercial con-
        text in which a question comes to the court;
       Providing practical perspectives on the consequences
        of potential outcomes;
4                                                   No. 18-3644

       Relaying views on legal questions by employing the
        tools of social science;
       Supplying empirical data informing one or another
        question implicated by an appeal;
       Conveying instruction on highly technical, scientific,
        or specialized subjects beyond the ken of most gener-
        alist federal judges;
       Identifying how other jurisdictions—cities, states, or
        even foreign countries—have approached one or an-
        other aspect of a legal question or regulatory chal-
        lenge.
    The point, of course, is that an amicus curiae brief should
be additive—it should strive to offer something different,
new, and important. See 

. And a good
amicus brief does not have to be long. Indeed, shorter is often
better, and I offer that perspective knowing that it is more dif-
ficult to write a short, effective brief than a long, belabored
brief.
     Each of the amicus briefs tendered in this appeal meet these
standards. And that is so despite each brief containing some
unnecessary and unwelcomed (though perhaps inevitable)
repetition of Dynegy’s primary arguments. The Illinois Envi-
ronmental Regulatory Group briefly presents the history of
Illinois groundwater regulation from before Congress’s enact-
ment of the Clean Water Act through the present day, thereby
lending context to the cases cited by the parties and highlight-
ing the practical results if we decide to affirm. The United
States Chamber of Commerce likewise provides insight into
how an alternative federal scheme would apply in the absence
of Clean Water Act regulation. Finally, the Washington Legal
Foundation’s brief offers its own theory for how to best fit
No. 18-3644                                                 5

County of Maui into the existing federal scheme regulating the
pollutants at issue here. Members of the court might find any
or all of these additions helpful to deciding this appeal.