 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued January 14, 2015                  Decided July 7, 2015

                         No. 12-5334

                     RHONDA N. BAIRD,
                        APPELLANT

                              v.

JOSHUA GOTBAUM, DIRECTOR, PENSION BENEFIT GUARANTY
                  CORPORATION,
                    APPELLEE


                 Consolidated with 13-5156


        Appeals from the United States District Court
                for the District of Columbia
                    (No. 1:09-cv-01091)
                    (No. 1:11-cv-00669)


     Rhonda N. Baird, pro se, argued the cause and filed briefs
for the appellant.

     Jane M. Lyons, Assistant United States Attorney, argued
the cause for the appellee. Ronald C. Machen Jr., United
States Attorney, and R. Craig Lawrence and Alexander D.
Shoaibi, Assistant United States Attorneys, were with her on
brief.
                               2
   Before: HENDERSON, Circuit Judge, and WILLIAMS and
RANDOLPH, Senior Circuit Judges.

    Opinion for the Court filed by Circuit Judge HENDERSON.

     KAREN LECRAFT HENDERSON, Circuit Judge: Rhonda
Baird is a lawyer for the Pension Benefit Guarantee
Corporation (PBGC). She is the former president of the
employees’ union and a frequent filer of Title VII claims on
behalf of herself and others. Baird claims that, in retaliation
for her Title VII activities, the PBGC made her work
environment a hostile one. Her two complaints recount
several instances of rude emails, name-calling, lost tempers
and unprofessional behavior—all of which the PBGC failed to
investigate or remediate. Although Baird paints an unpleasant
picture, she does not allege that the PBGC has done anything
illegal. See Burlington N. & Santa Fe Ry. Co. v. White, 548
U.S. 53, 68 (2006) (“Title VII . . . does not set forth a general
civility code for the American workplace.” (quotation marks
omitted)). We therefore affirm the dismissal of her two
complaints.

                               I.

     Title VII prohibits a federal employer from discriminating
against an employee based on his race, sex, religion or
nationality. 42 U.S.C. § 2000e–16(a). It also contains an
anti-retaliation provision, barring an employer from taking an
adverse action against an employee “because he has opposed
any practice made unlawful by [Title VII], or because he has
made a charge, testified, assisted, or participated in any manner
in an investigation, proceeding or hearing under [Title VII].”
                                3
Id. § 2000e–3(a). 1 To prove retaliation, a plaintiff must show
that “(1) [he] engaged in protected activity; (2) he was
subjected to an adverse employment action; and (3) there was a
causal link between the protected activity and the adverse
action.” Hairston v. Vance-Cooks, 773 F.3d 266, 275 (D.C.
Cir. 2014). An adverse action must be “material”—i.e.,
“harmful to the point that [it] could well dissuade a reasonable
worker from making or supporting a charge of discrimination.”
Burlington N., 548 U.S. at 68, 57.

     We have recognized a special type of retaliation claim
based on a “hostile work environment.” See Hussain v.
Nicholson, 435 F.3d 359, 366 (D.C. Cir. 2006). A hostile
environment consists of several individual acts that “may not
be actionable on [their] own” but become actionable due to
their “cumulative effect.” Nat’l R.R. Passenger Corp. v.
Morgan, 536 U.S. 101, 115 (2002). The constituent acts must
be “adequately linked” such that they form “a coherent hostile
environment claim.” Baird v. Gotbaum (Baird I), 662 F.3d
1246, 1251 (D.C. Cir. 2011). For example, they might
“involve the same type of employment actions, occur relatively
frequently, and [be] perpetrated by the same managers.” Id.
(alterations omitted). In addition, the acts must be “of such
severity or pervasiveness as to alter the conditions of . . .
employment and create an abusive working environment.”
Hussain, 435 F.3d at 366 (quotation marks and alterations
omitted). Severity and pervasiveness are determined by
reference to “all the circumstances,” including “the frequency
of the discriminatory conduct; its severity; whether it is
physically threatening or humiliating, or a mere offensive
utterance; and whether it unreasonably interferes with an

    1
       The anti-retaliation provision applies to the PBGC by virtue
of 42 U.S.C. § 2000e–16. See Taylor v. Solis, 571 F.3d 1313, 1320
(D.C. Cir. 2009).
                                  4
employee’s work performance.” Harris v. Forklift Sys., Inc.,
510 U.S. 17, 23 (1993). The standard is an objective one. Id.
at 21.

                                  II.

     This consolidated appeal is the culmination of six years of
litigation involving two complaints, four district court
decisions, an appeal and a remand. Below, we outline the
facts and procedural history behind each appeal. 2

                         A. No. 12-5334

      Baird filed her first amended complaint in February 2010.
In it, she alleged Title VII claims based on various run-ins with
her coworkers between 2002 and 2009. In November 2002,
for example, John Paliga verbally assaulted Baird and
advanced ominously into her office. In Spring 2005, Dwayne
Jeffers sent an email calling Baird “psychotic” and, in January
2007, Raymond Forster circulated an email suggesting she
experienced “litigation induced hallucinations.” Baird was
falsely accused by Richard Lattimer and another human
resources officer of disseminating anonymous flyers in June
2005. In January 2006, Baird was temporarily blocked from
sending emails to Jeffers and Robert Perry. Baird learned in
November 2006 that Jeffers had sent an arbitration file
containing her confidential information to a private lawyer.
In Summer 2008, Scott Schwartz said that someone should
“overthrow” Baird as union president and then falsely accused
her of violating her ethical duties. In November 2008, Robert
Moreno falsely accused Baird of spreading rumors and, in
     2
       All facts come from Baird’s two complaints. Reviewing a
motion to dismiss, “[w]e accept [her] factual allegations . . . as true
and we draw all inferences in her favor.” Brown v. Sessoms, 774
F.3d 1016, 1020 (D.C. Cir. 2014) (quotation marks omitted).
                                5
February 2009, he yelled at her during a deposition. In
September 2009, Michael O’Connell falsely accused Baird of
sending a harassing email. That same month, Gilbert
Martinez cut Baird out of certain work communications,
stormed out of a meeting and refused to complete his work on
time. Baird formally complained to the PBGC’s human
resources department about many of these incidents but it
failed to investigate them. According to Baird, these actions
constituted discrimination, retaliation and a hostile work
environment.

     The PBGC moved to dismiss Baird’s complaint, which
motion the district court granted in toto. See 744 F. Supp. 2d
279, 296 (D.D.C. 2010). We affirmed in part and reversed in
part. Baird I, 662 F.3d at 1253. We agreed that Baird failed
to state a stand-alone claim of discrimination or retaliation
because the incidents she identified were not materially
adverse. See id. at 1249–50. We characterized Baird’s
allegations as “slights”—“the sort of ‘public humiliation or
loss of reputation’ that we have consistently classified as
falling below the requirements for an adverse employment
action.” Id. As for her retaliatory hostile-work-environment
claim, we reversed the district court on two points of law.
First, the district court dismissed many of Baird’s allegations
as untimely without first applying the special rules that govern
hostile-work-environment claims. Id. at 1251. See generally
Morgan, 536 U.S. at 117–20 (hostile-work-environment
claims are timely if constituent acts are adequately connected
and at least one falls within filing period). Second, the district
court held that the incidents supporting Baird’s stand-alone
claims could not also support her hostile-work-environment
claim. Baird I, 662 F.3d at 1252–53. We disagreed, noting
that “plaintiffs are free to plead alternative theories of harm
that might stem from the same allegedly harmful conduct.”
Id. at 1252. Based on these legal errors, we remanded Baird’s
                                6
retaliatory hostile-work-environment claim to the district
court. Id. at 1253. But we expressed “no opinion” on
whether the claim would ultimately survive a Rule 12(b)(6)
motion. Id.

     On remand, the PBGC again moved to dismiss and the
district court again granted it. See 888 F. Supp. 2d 63, 78
(D.D.C. 2012). The court concluded that Baird’s allegations,
taken together, did not sufficiently allege a retaliatory hostile
work environment. Id. at 73. Baird timely appealed.

                        B. No. 13-5156

     In April 2011—before we issued our decision on
appeal—Baird filed a second complaint, which was assigned to
a different district judge. The complaint rehashed all of the
allegations from Baird’s first complaint and added several new
ones. Specifically, in February 2010, Schwartz falsely
claimed that a federal judge had referred to Baird as a “cancer”
and then verbally assaulted her while pounding his fists on a
table. In September and October 2010, the PBGC refused to
settle a matter with Baird and refused to honor an earlier
arbitral award. Around the same time, Martinez engaged in
“hostilities” toward Baird. As before, Baird reported these
incidents to the PBGC’s human resources department and it
failed to investigate or remediate them. Baird’s second
complaint, like her first, alleged discrimination, retaliation and
a hostile work environment. But once we issued our decision
in Baird I, Baird voluntarily dropped all claims except the
retaliatory hostile-work-environment claim.

     In the meantime, the district judge in Baird’s first suit
issued her remand decision. This prompted the judge in
Baird’s second suit to dismiss a large swath of the allegations
therein. See Order at 11, No. 1:11-cv-00669 (D.D.C. Jan. 3,
2013). He concluded that Baird was barred by issue
                               7
preclusion from relitigating the allegations his colleague had
already considered and rejected. Id. at 7–8. At a subsequent
hearing, he considered Baird’s remaining allegations and
dismissed them too for failure to state a retaliatory
hostile-work-environment claim.          Order at 11, No.
1:11-cv-00669 (D.D.C. May 17, 2013).             Baird timely
appealed. We consolidated the appeal from the dismissal in
No. 13-5156 with the appeal from the remand decision in No.
12-5334.

                              III.

     Both of Baird’s complaints are now before us and both
allege a claim of retaliatory hostile work environment. The
district judges dismissed many of Baird’s allegations on
timeliness and preclusion grounds. We commend that
approach. Although non-jurisdictional, issue preclusion and
timeliness are mandatory requirements that serve important
purposes. See N.Y. Shipping Ass’n, Inc. v. Fed. Mar.
Comm’n, 854 F.2d 1338, 1352 (D.C. Cir. 1988); Mondy v.
Sec’y of Army, 845 F.2d 1051, 1057 (D.C. Cir. 1988). And
despite Baird’s best attempts, “a plaintiff has no right to
maintain two separate actions involving the same subject
matter at the same time in the same court and against the same
defendant.” Zerilli v. Evening News Ass’n, 628 F.2d 217, 222
(D.C. Cir. 1980) (quotation marks omitted). Nevertheless, as
an appellate court, we can “affirm the District Court on any
valid ground, and need not follow the same mode of analysis.”
Molerio v. FBI, 749 F.2d 815, 820 (D.C. Cir. 1984). We will
therefore bypass the more difficult questions of timeliness and
res judicata and consider instead whether Baird’s two
complaints, taken together, state a claim of retaliatory hostile
work environment.
                                8
     As      noted,    the     constituent     acts    of    a
hostile-work-environment claim must be “adequately linked”
to one another. Baird I, 662 F.3d at 1251. The intermittent
spats identified in Baird’s complaints, however—spanning
eight years and involving different people doing different
things in different contexts—have little to do with each other.
Cf. id. Baird makes no serious attempt to tie them together.
The one common thread she does identify is the repeated
failure of the PBGC’s human resources department to
investigate or remediate her internal complaints.

     This theory, however, suffers from a different problem.
A retaliatory failure-to-remediate claim is not actionable
unless the underlying incident would itself be actionable. See
id. at 1249 (“a claim of . . . retaliatory failure to remediate may
be sufficient if the uncorrected action would . . . be of enough
significance to qualify as an adverse action”). In other words,
if certain conduct would not “dissuade a reasonable worker
from making or supporting a charge of discrimination,”
Burlington N., 548 U.S. at 57, neither would an employer’s
failure to investigate that conduct. A trivial incident does not
become nontrivial because an employer declines to look into it.
Title VII is aimed at preventing discrimination, not auditing the
responsiveness of human resources departments.

     Here, the incidents the PBGC failed to remediate would
not themselves constitute a retaliatory hostile work
environment. We already considered many of them in Baird I
and concluded they were immaterial “slights.” 662 F.3d at
1250. Baird’s other allegations are more of the same. They
consist of occasional name-calling, rude emails, lost tempers
and workplace disagreements—the kind of conduct courts
frequently deem uncognizable under Title VII.                  See
Burlington N., 548 U.S. at 68 (“personality conflicts . . . are not
actionable” under Title VII); Brooks v. Grundmann, 748 F.3d
                               9
1273, 1277–78 (D.C. Cir. 2014) (“the ordinary tribulations of
the workplace, [i.e.,] a series of petty insults, vindictive
behavior, and angry recriminations . . . are not actionable under
Title VII” (quotation marks and citation omitted)); id. at 1277
(“isolated expression of frustration” where employee “yelled,”
“violently threw a book” and “slamm[ed] down his hand” did
not support hostile-work-environment claim); Baloch v.
Kempthorne, 550 F.3d 1191, 1199 (D.C. Cir. 2008) (“sporadic
verbal altercations or disagreements do not qualify as adverse
actions”); Forkkio v. Powell, 306 F.3d 1127, 1130–31 (D.C.
Cir. 2002) (“public humiliation,” “loss of reputation” and loss
of prestige are not actionable). To borrow from Baird I, “[w]e
do not believe that the PBGC’s failure to remedy the various
critiques and epithets to which Baird’s fellow employees
subjected her would have persuaded a reasonable employee to
refrain from making or supporting charges of discrimination.”
662 F.3d at 1250. The sheer volume of Baird’s allegations
does not change our conclusion: a long list of trivial incidents
is no more a hostile work environment than a pile of feathers is
a crushing weight.

     Baird does not really argue to the contrary. Instead, she
contends that the PBGC’s conduct was actionable because it
took a serious toll on her emotional and physical health. We,
of course, assume this is true but the standard for severity and
pervasiveness is nonetheless an objective one. Harris, 510
U.S. at 21. Given the objectively immaterial nature of her
allegations, the fact that Baird suffered subjective harm is
insufficient on its own. Baird further argues that the PBGC’s
failure to investigate her internal complaints is actionable
because it violated the agency’s own workplace rules. We
already considered and rejected this argument in Baird I. See
662 F.3d at 1249–50.
                             10
    Accordingly, we affirm the district courts’ dismissals of
Baird’s complaints in Nos. 12-5334 and 13-5156.

                                                 So ordered.
