                 FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

ARAMARK FACILITY SERVICES,           
                Plaintiff-counter-
              defendant-Appellee,
                                           No. 06-56662
               v.
SERVICE EMPLOYEES INTERNATIONAL             D.C. No.
                                         CV-06-00608-GPS
UNION, LOCAL 1877, AFL CIO
                                            OPINION
CLC,
              Defendant-counter-
              claimant-Appellant.
                                     
      Appeal from the United States District Court
          for the Central District of California
      George P. Schiavelli, District Judge, Presiding

                  Argued and Submitted
           April 10, 2008—Pasadena, California

                   Filed June 16, 2008

  Before: Cynthia Holcomb Hall, Thomas G. Nelson, and
           Barry G. Silverman, Circuit Judges.

                  Opinion by Judge Hall




                           6913
6916 ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L


                        COUNSEL

Steven R. Wall and Robert Jon Hendricks, Morgan, Lewis &
Brockius, Philadelphia, Pennsylvania, and Los Angeles, Cali-
fornia, for the defendant-counter-claimant-appellant.

Manjari Chawla and David A. Rosenfeld, Weinberg, Roger &
Rosenfeld, Alameda, California, for the plaintiff-counter-
defendant-appellee.

Monica Guizar, National Immigration Law Center, Los Ange-
les, California, for the amicus curiae.


                         OPINION

HALL, Circuit Judge:

                  I.   INTRODUCTION

   This case arose from the response by Aramark Facility Ser-
vices (“Aramark”) to a “no-match letter” from the Social
Security Administration (“SSA”), which indicated that Ara-
      ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L 6917
mark had reported information for 48 of its employees at the
Staples Center in downtown Los Angeles that did not match
the SSA’s database. Suspecting immigration violations, Ara-
mark told the listed employees they had three days to correct
the mismatches by proving they had begun the process of
applying for a new social security card. Seven to ten days
later, Aramark fired the 33 employees who did not timely
comply.

   Local 1877 of the Service Employees International Union
(“SEIU”) filed a grievance on behalf of the fired workers,
contending the terminations were without just cause and thus
in breach of the collective bargaining agreement (“CBA”)
between Aramark and SEIU. An arbitrator ruled for SEIU and
awarded the fired workers back-pay and reinstatement, find-
ing there was no convincing information that any of the fired
workers were undocumented. The district court vacated the
award on the ground that it violated public policy. SEIU
timely appealed.

   This case boils down to a single issue: whether the SSA’s
no-match letter — and the fired employees’ responses — put
Aramark on constructive notice that it was employing
undocumented workers. If so, the arbitrator’s award would
force Aramark to violate federal immigration law, and there-
fore was properly vacated as against public policy. If not, the
award must stand.

   As we explain below, Aramark has not established con-
structive knowledge of any immigration violations. Construc-
tive knowledge is to be narrowly construed in the immigration
context and requires positive information of a worker’s
undocumented status. Moreover, we are required to defer to
the arbitrator’s factual findings even when evaluating an
award for violation of public policy. Accordingly, given the
extremely short time that Aramark gave its employees to
return with further documents and the arbitrator’s finding that
Aramark had no “convincing information” of immigration
6918 ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L
violations, the employees’ failure to meet the deadline simply
is not probative enough of their immigration status to indicate
that public policy would be violated if they were reinstated
and given backpay. Therefore, the district court erred and the
award must be confirmed.

II.    FACTUAL AND PROCEDURAL BACKGROUND

A. The Letter Sent to Aramark and Aramark’s
Response

   Aramark is a corporation that employs approximately
170,000 people in the United States, and its facilities manage-
ment division provides labor for the Staples Center, a 19,000-
seat sports and entertainment venue in downtown Los Ange-
les. In early 2003, Aramark received letters from the SSA
notifying it that the social security numbers of some 3,300 of
its employees nationwide did not match those in the SSA’s
database. Aramark reacted to these “no-match” letters by ask-
ing its regional managers to confirm that the information it
provided SSA matched the information provided by employ-
ees and, if so, to require corrective steps from the employees
they supervised. On April 15 and 16, 2003, instructions were
relayed to 48 Aramark employees working at the Staples Cen-
ter, who were represented by SEIU and employed pursuant to
a CBA between SEIU and Aramark. Aramark’s instructions
to the Staples Center employees read as follows:

      1.   Please return to the [SSA] office to correct [the]
           discrepancy

      2.   Return to Aramark Facility Services at Staples
           Center with one of two items.

           a) A new social security card, [sic] photo
           copies will not be accepted

           b) Verification form that shows a new card
           is being processed.
      ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L 6919
    3.   You have three working days from the post-
         marked date of this letter to bring either.[ ]You
         have 90 days from the date of re-application on
         your receipt to bring in your new card.

    4.   A new card or verification of renewal must be
         in the office no later then [sic] close of business
         4pm on Wednesday April 23rd, 2003.

         ...

    If you fail to comply with this letter and you do not
    bring in the proper documents then unfortunately
    your employment with Aramark will be terminated.

(emphasis added).

  No employee was aware of the policy before receiving the
mismatch letter. Believing the three-day turnaround time was
too onerous, SEIU requested an extension, but Aramark
denied this request.

   Fifteen of the Staples Center employees obtained the
requested documentation in time and continued to work.
However, 33 employees did not timely comply and were
fired. The last day of work for virtually all of them was either
April 16, 2003, or April 18, 2003. Most were officially fired
effective April 23, while a few were fired April 28, 2003.
Although the instruction letters from Aramark stated that
employees were expected to visit an SSA office and provide
the initial documentation within three days, the employees
were actually given seven to ten days to provide the required
paperwork, though nothing in the record indicates that they
knew they had this much time. The fired workers were told
that they would be rehired if they supplied the required docu-
mentation; nothing indicates when they received this informa-
tion.
6920 ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L
   Though it suspected immigration violations, Aramark did
not know for sure why the terminated employees did not pro-
vide additional documents and even argued to the arbitrator
that they could have had “valid” work eligibility. Each of the
fired employees had, at the time they were hired, properly
completed the federal Employee Eligibility Verification Form
(“Form I-9”) and provided Aramark with facially valid docu-
ments establishing their identity and eligibility to work in the
United States. Moreover, Aramark was not notified by any
federal agency that its workers were suspected of being
undocumented.

B.   Arbitration

   After the terminations, SEIU filed a grievance on behalf of
the Staples Center employees, contending that Aramark had
violated the CBA by firing them without just cause. Pursuant
to the CBA, the matter was submitted to binding arbitration.
Over two days of hearings, the parties presented testimony
concerning the no-match letters, Aramark’s obligation to
comply with applicable tax and immigration laws, and the
procedures by which the Staples Center employees were fired.

   Ultimately, the arbitrator concluded that there was no “con-
vincing information” that any of the terminated workers were
undocumented. He thus found that the firings were without
just cause, ruled in favor of SEIU, and awarded the workers
back-pay and reinstatement.

C.   District Court Proceedings

   After the arbitrator’s ruling, Aramark filed a complaint in
U.S. District Court to vacate the arbitration award, and SEIU
counter-claimed to confirm it. The parties filed cross-motions
for summary judgment, and at a hearing held September 29,
2006, the district court ruled in favor of Aramark. The court
reasoned that because the fired employees failed to indicate
that they were beginning the process of correcting the SSN
      ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L 6921
mismatch, Aramark had constructive notice that they were
ineligible to work in the United States. Therefore, the court
held that the arbitrator’s award of reinstatement and back-pay
violated public policy because it would require Aramark to
violate the immigration laws. SEIU timely appealed.

              III.   STANDARD OF REVIEW

   We review vacation of arbitration awards like “any other
district court decision . . . accepting findings of fact that are
not ‘clearly erroneous’ but deciding questions of law de
novo.” Barnes v. Logan, 122 F.3d 820, 821 (9th Cir. 1997)
(quoting First Options of Chicago, Inc. v. Kaplan, 514 U.S.
938, 947-48 (1995)). Here, the district court resolved the mat-
ter on the parties’ cross-motions for summary judgment,
which necessarily present questions of law. We must there-
fore decide de novo whether there are any genuine issues of
material fact and whether the district court correctly applied
the relevant substantive law. See Olsen v. Idaho State Bd. of
Med., 363 F.3d 916, 922 (9th Cir. 2004); Arakaki v. Hawaii,
314 F.3d 1091, 1094 (9th Cir. 2002) (stating standard for
cross-motions).

                     IV.   DISCUSSION

A. The Legal Standard for Review of the Arbitrator’s
Award

   “The scope of review of an arbitrator’s decision in a labor
dispute is extremely narrow.” Federated Dep’t Stores v.
United Food & Commercial Workers Union, Local 1442, 901
F.2d 1494, 1496 (9th Cir. 1990). Arbitration awards are ordi-
narily upheld so long as they represent a “plausible interpreta-
tion of the contract.” Phoenix Newspapers, Inc. v. Phoenix
Mailers Union Local 752, 989 F.2d 1077, 1080 (9th Cir.
1993). However, one narrow exception to this generally defer-
ential review is the “now-settled rule that a court need not, in
fact cannot, enforce an award which violates public policy.”
6922 ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L
Stead Motors v. Automotive Machinists Lodge No. 1173, 886
F.2d 1200, 1209 (9th Cir. 1989) (en banc); accord SFIC
Properties, Inc. v. Int’l Ass’n of Machinists & Aerospace
Workers, 103 F.3d 923, 925 (9th Cir. 2003). “[T]he question
of public policy is ultimately one for resolution by the
courts.” United Food & Commercial Workers Int’l Union,
Local 588 v. Foster Poultry Farms, 74 F.3d 169, 174 (9th Cir.
1995). The public policy exception is Aramark’s sole basis for
attacking the arbitration award in this case.

    [1] “To vacate an arbitration award on public policy
grounds, we must (1) find that an explicit, well defined and
dominant policy exists here and (2) that the policy is one that
specifically militates against the relief ordered by the arbitra-
tor.” Id. at 174 (citations and quotation marks omitted);
accord W.R. Grace & Co. v. Local Union 759, Int’l Union of
United Rubber, Cork, Linoleum & Plastic Workers of Am.,
461 U.S. 757, 766 (1983). In evaluating a public policy argu-
ment, we “must focus on the award itself, not the behavior or
conduct of the party in question.” S. Cal. Gas Co. v. Utility
Workers Union of Am., Local 132, AFL-CIO, 265 F.3d 787,
795 (9th Cir. 2001). We have stressed that “courts should be
reluctant to vacate arbitral awards on public policy grounds,”
because “[t]he finality of arbitral awards must be preserved if
arbitration is to remain a desirable alternative to courtroom
litigation.” Arizona Elec. Power Co-op., Inc. v. Berkeley, 59
F.3d 988, 992 (9th Cir. 1995). Moreover, before the award
will be vacated as against public policy, the policy violation
must be “clearly shown.” Stead Motors, 886 F.2d at 1225
(quoting United Paperworkers Int’l Union, AFL-CIO v.
Misco, Inc., 484 U.S. 29, 43 (1987)).

   Importantly, the public policy inquiry proceeds by taking
the facts as found by the arbitrator. “The parties did not bar-
gain for the facts to be found by a court, but by an arbitrator
chosen by them . . . [.] Nor does the fact that it is inquiring
into a possible violation of public policy excuse a court for
doing the arbitrator’s task.” Id. at 1211 (quoting Misco, 484
        ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L 6923
U.S. at 45); accord Prudential-Bache Secs., Inc. v. Tanner, 72
F.3d 234, 242 (1st Cir. 1995); Bd. of County Comm’rs of
Lawrence County, Ohio v. L. Robert Kimball & Assocs., 860
F.2d 683, 686 (6th Cir. 1988); see also Int’l Bhd. of Elec.
Workers, Local 97 v. Niagra Mohawk Power Corp., 143 F.3d
704, 716 (2d Cir. 1998) (“[I]n reviewing an arbitral award for
possible violations of public policy . . . [a] court is not autho-
rized to revisit or question the fact-finding or the reasoning
which produced the award.”); E.I. DuPont de Nemours & Co.
v. Grasselli Employees Indep. Ass’n, 790 F.2d 611, 617 (7th
Cir. 1986) (rejecting a public policy attack because it would
“require[ ] this Court to re-find facts found by the arbitrator”),
disapproved on other grounds by Misco, 484 U.S. at 35 n.7.
Accordingly, in evaluating whether the arbitrator’s award vio-
lated public policy here, we will not revisit the arbitrator’s
factual findings, in particular the finding that there was no
“convincing information” that any of the terminated workers
were undocumented.

B.     Analysis

  As we explain below, Aramark has identified a sufficiently
explicit, well-defined, and dominant public policy — compli-
ance with immigration law — that, in the proper case, would
be the basis for vacating an arbitration award. However, the
policy in this case does not specifically militate against the
arbitrator’s award of reinstatement and back-pay.

  1.    The Asserted Public Policy

   [2] The main public policy to which Aramark points is
expressed in the Immigration Reform and Control Act of
1986 (“IRCA”), Pub. L. No. 99-603, 100 Stat. 3359 (1986).
Specifically, Aramark cites the laws that (1) employers are
subject to civil and criminal liability if they employ undocu-
mented workers “knowing” of their undocumented status, and
(2) the term “knowing” includes constructive knowledge. See
6924 ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L
8 U.S.C. § 1324a(a)(1), (2);1 8 C.F.R. § 274a.1(l). We agree
that these policies are germane to the arbitrator’s reinstate-
ment award because they would necessarily be violated if
Aramark knowingly reinstated undocumented workers. They
are also germane to the back-pay award because the Supreme
Court has held that immigration policy precludes such awards
to undocumented workers. Hoffman Plastic Compounds, Inc.
v. NLRB, 535 U.S. 137, 148-152 (2002). These policies are
“explicit,” “well-defined,” and “dominant,” expressed not by
“general considerations” but by the IRCA, its implementing
regulations, and Supreme Court case law interpreting it. They
are therefore an adequate basis for Aramark’s public policy
attack. See S. Cal. Gas Co., 265 F.3d at 794-95 (quoting
Misco, 484 U.S. at 42).2
  1
   8 U.S.C. § 1324a(a) provides in relevant part:
      (1) In general
      It is unlawful for a person or other entity—
      (A) to hire, or to recruit or refer for a fee, for employment in the
      United States an alien knowing the alien is an unauthorized alien
      (as defined in subsection (h)(3) of this section) with respect to
      such employment, or
      (B) (i) to hire for employment in the United States an individual
      without complying with the requirements of subsection (b) of this
      section or (ii) if the person or entity is an agricultural association,
      agricultural employer, or farm labor contractor (as defined in sec-
      tion 1802 of Title 29), to hire, or to recruit or refer for a fee, for
      employment in the United States an individual without comply-
      ing with the requirements of subsection (b) of this section.
      (2) Continuing employment
     It is unlawful for a person or other entity, after hiring an alien for
     employment in accordance with paragraph (1), to continue to
     employ the alien in the United States knowing the alien is (or has
     become) an unauthorized alien with respect to such employment.
  2
    Aramark also argues in passing that enforcement of the arbitrator’s
award would violate tax policy, citing Treasury Department regulations
prohibiting employers from reporting incorrect SSN information to the
IRS. 26 C.F.R. § 301.6721-1(c)(2)(i). However, this policy would not
       ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L 6925
  2. Whether the Policy Specifically Militates Against
  the Award

   The more difficult question is whether these policies “spe-
cifically militate” against the arbitrator’s award here — that
is, whether the arbitrator’s award would have forced Aramark
to reinstate and provide back-pay to undocumented workers
where Aramark had “constructive knowledge” that they were
undocumented. See 8 U.S.C. § 1324a(a)(1), (2); 8 C.F.R.
§ 274a.1(l).

   [3] As defined in the relevant regulation, “[c]onstructive
knowledge is knowledge that may fairly be inferred through
notice of certain facts and circumstances that would lead a
person, through the exercise of reasonable care, to know
about a certain condition.” 8 C.F.R. § 274a.1(l). We have
stressed that, for purposes of the IRCA, “constructive knowl-
edge” is to be narrowly construed:

     IRCA . . . is delicately balanced to serve the goal of
     preventing unauthorized alien employment while
     avoiding discrimination against citizens and autho-
     rized aliens. The doctrine of constructive knowledge
     has great potential to upset that balance, and it
     should not be expansively applied. The statute pro-
     hibits the hiring of an alien “knowing the alien is an
     unauthorized alien . . . with respect to such employ-
     ment.” 8 U.S.C. § 1324a(a)(1)(A) (emphasis added).
     Insofar as that prohibition refers to actual knowl-
     edge, as it appears to on its face, any employer can

“specifically militate” against the arbitrator’s award, because the award
did not require reporting of incorrect numbers, or prohibit further verifica-
tion procedures after the employees were reinstated. Aramark also sug-
gests that it might be forced to violate RICO and the Sarbanes-Oxley Act
if the arbitrator’s award were enforced. But it has waived these arguments
by failing adequately to brief them. See Indep. Towers of Wash. v. Wash-
ington, 350 F.3d 925, 929-30 (9th Cir. 2003).
6926 ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L
      avoid the prohibited conduct with reasonable ease.
      When the scope of liability is expanded by the doc-
      trine of constructive knowledge, the employer is sub-
      ject to penalties for a range of undefined acts that
      may result in knowledge being imputed to him. To
      guard against unknowing violations, the employer
      may, again, avoid hiring anyone with an appearance
      of alienage. To preserve Congress’ intent in passing
      the employer sanctions provisions of IRCA, then, the
      doctrine of constructive knowledge must be spar-
      ingly applied.

Collins Foods Int’l, Inc. v. INS, 948 F.2d 549, 554-55 (9th
Cir. 1991). In Collins, we reversed an ALJ’s holding that the
employer had constructive knowledge of an immigration vio-
lation because it had extended an offer of employment over
the telephone and overlooked that the employee’s social
security card was fraudulent. See id. at 551, 555-56. We dis-
tinguished other cases finding constructive knowledge on the
grounds that the employer there did not have “positive infor-
mation” that the employee was undocumented. Id. at 555. In
those distinguishable cases, on which Aramark relies heavily
here, the INS specifically visited the employer and notified it
that its employers were suspected unlawful aliens and should
be terminated if inspection of their documents did not allay
the concerns. See New El Rey Sausage Co. v. INS, 925 F.2d
1153, 1155 (9th Cir. 1991); Mester Mfg. Co. v. INS, 879 F.2d
561, 564 (9th Cir. 1989).3
  3
   Contrary to Aramark’s contention, Collins is not distinguishable on the
ground that in this case, there is no accusation of discriminatory conduct
by the employer. Collins did not involve discrimination either. Rather, the
court stressed that by too expansively viewing constructive knowledge, the
doctrine would risk encouraging employers to avoid liability through dis-
criminatory practices. 948 F.2d at 554-55; see also Incalza v. Fendi N.
Am., Inc., 479 F.3d 1005, 1013 (9th Cir. 2007) (holding that the IRCA did
not require an employer to terminate a worker whose visa had expired but
could be readily renewed).
       ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L 6927
   Here, Aramark essentially argues that two facts gave it con-
structive notice of immigration violations: (1) the no-match
letters themselves and (2) the employees’ responses (or lack
thereof). We address each contention in turn.

      a.   The Letters Themselves

   [4] Given the narrow scope of the constructive knowledge
doctrine, the “no-match” letters themselves could not have put
Aramark on constructive notice that any particular employee
mentioned was undocumented. To understand why, some
background on the purpose of the no-match letters is helpful.
The SSA routinely sends the letters when an employer’s W-2
records differ from the SSA’s database regarding an employ-
ee’s social security number (“SSN”). When there is a discrep-
ancy, the SSA cannot post an employee’s social security
earnings to his or her account, and instead must deposit the
funds into a national “earnings suspense fund,” which is a
very large fund containing more than 250 million mismatched
records and totaling more than $500 billion. Social Security
Number High-Risk Issues: Hearing Before the Subcomms. on
Social Security and Oversight of the H. Comm. on Ways and
Means, 109th Cong. 60 (Feb. 16, 2006) (statement of Patrick
P. O’Carroll, SSA Inspector General), available at
http://waysandmeans.house.gov/hearings.asp?formmode=
printfriendly&id=4710 (last visited June 9, 2008).4 The
Inspector General of the SSA believes that “the chief cause of
wage items being posted to the [earnings suspense fund]
instead of an individual’s earnings record is unauthorized
work by noncitizens.” Id. However, the main purpose of the
no-match letters is not immigration-related, but rather is sim-
ply to indicate to workers that their earnings are not being
properly credited. See id. (statement of James B. Lockhart, III,
Deputy Commissioner of Social Security), available at http://
  4
    Both the parties and amicus cite various agency and legislative materi-
als that are not part of the record. We treat these citations as requests for
judicial notice and grant the requests. Fed. R. Evid. 201(b), (d).
6928 ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L
waysandmeans.house.gov/hearings.asp?formmode=
printfriendly&id=4708 (last visited June 9, 2008).

   In addition to misuse by undocumented workers, SSN mis-
matches could generate a no-match letter for many reasons,
including typographical errors, name changes, compound last
names prevalent in immigrant communities, and inaccurate or
incomplete employer records. By SSA’s own estimates,
approximately 17.8 million of the 430 million entries in its
database (called “NUMIDENT”) contain errors, including
about 3.3 million entries that mis-classify foreign-born U.S.
citizens as aliens. Congressional Response Report: Accuracy
of the Social Security Administration’s NUMIDENT File
(Dec. 2006), available at http://www.socialsecurity.gov/oig/
ADOBEPDF/auditt xt/A-08-06-26100.htm (last visited June
9, 2008).

   [5] As a result, an SSN discrepancy does not automatically
mean that an employee is undocumented or lacks proper work
authorization. In fact, the SSA tells employers that the infor-
mation it provides them “does not make any statement about
. . . immigration status” and “is not a basis, in and of itself,
to take any adverse action against the employee.” Social
Security Number Verification Service Handbook, available at
http://www.ssa.gov/employer/ssnvs_handbk.htm (last visited
June 9, 2008). This information is included in the no-match
letters, and was added at the urging of advocacy groups such
as amicus National Immigration Law Center to combat abuses
by employers who assumed that the workers mentioned in the
letters were undocumented.

   Moreover, employers do not face any penalty from SSA,
which lacks an enforcement arm, for ignoring a no-match let-
ter. The IRS also imposes no sanctions stemming from the no-
match letters. It requires no additional solicitations of an
employee’s SSN unless it sends a “penalty notice” to the
employer indicating that the SSN is incorrect — a notice Ara-
mark does not contend it received. Internal Revenue Service
      ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L 6929
Pub. 1586: Reasonable Cause Regulations and Requirements
for Missing and Incorrect Name/TINs at 8-9 (2007 Rev.),
available at http://www.irs.gov/pub/irs-pdf/p1586.pdf (last
visited June 9, 2008). The IRS also does not require any
reverification of a worker’s documents following receipt of a
mismatch notice from the SSA. See id. at 9.

   To the same effect are statements from the Office of Spe-
cial Counsel of Immigration-Related Practices, which is an
agency of the Department of Justice authorized to investigate
unfair immigration-related employment practices. See 8
U.S.C. § 1324b(c). The Office of Special Counsel states that
“[a] no match does not mean that an individual is undocu-
mented” and that employers “should not use the mismatch let-
ter by itself as the reason for taking any adverse employment
action against any employee.” Office of Special Counsel, Fre-
quently Asked Questions, available at http://www.usdoj.gov/
crt/osc/htm/facts.htm#verify (last visited June 9, 2008).

   As Aramark notes, the Department of Homeland Security
(“DHS”) recently has taken steps to use the no-match letters
in its enforcement of the immigration laws. In June 2006,
DHS proposed to amend 8 C.F.R. § 274a.1, which sets forth
DHS interpretations of terms including “knowing,” to include
receipt of no-match letters in its discussion of “constructive
knowledge.” Safe-Harbor Procedures for Employers Who
Receive a No-Match Letter, 71 Fed. Reg. 34281-01, 34281
(June 14, 2006). After some changes prompted by extensive
public comment, see 72 Fed. Reg. 45611 (Aug. 15, 2007), the
proposed amendment was adopted and the resulting regula-
tion currently provides in relevant part:

    The term knowing includes having actual or con-
    structive knowledge. Constructive knowledge is
    knowledge that may fairly be inferred through notice
    of certain facts and circumstances that would lead a
    person, through the exercise of reasonable care, to
    know about a certain condition. Examples of situa-
6930 ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L
     tions where the employer may, depending on the
     totality of relevant circumstances, have constructive
     knowledge that an employee is an unauthorized alien
     include, but are not limited to, situations where the
     employer . . . [f]ails to take reasonable steps after
     receiving information indicating that the employee
     may be an alien who is not employment authorized,
     such as . . . [w]ritten notice to the employer from the
     Social Security Administration reporting earnings on
     a Form W-2 that employees’ names and correspond-
     ing social security account numbers fail to match
     Social Security Administration records.

8 C.F.R. § 274a.1(l) (emphases added). So, even the DHS reg-
ulations, which were adopted after Aramark received the let-
ter at issue here and are currently subject to a preliminary
injunction,5 would not treat the no-match letter by itself as
creating constructive knowledge of an immigration violation.
Instead, the regulations would look further to “the totality of
the circumstances” and whether the employer took reasonable
steps after receiving the no-match letter.

   [6] In sum, the letters Aramark received are not intended by
the SSA to contain “positive information” of immigration sta-
tus, and could be triggered by numerous reasons other than
fraudulent documents, including various errors in the SSA’s
NUMIDENT database. Indeed, the letters do not indicate that
   5
     In October 2007, the United States District Court for the Northern Dis-
trict of California preliminarily enjoined the government from enforcing
the new regulations, including through sending no-match letters that refer
to them. See AFL v. Chertoff, No. 07-4472, ___ F. Supp. 2d ___, 2007 WL
2972952, at *15 (N.D. Cal. Oct. 10, 2007). After the district court’s ruling,
the government then moved to stay proceedings pending new administra-
tive rule-making. The district court granted the motion and stayed pro-
ceedings until March 28, 2008. DHS then proposed to repromulgate the
regulation without change. See Safe-Harbor Procedures for Employers
Who Receive a No-Match Letter: Clarification; Initial Regulatory Flexibil-
ity Analysis, 73 Fed. Reg. 15944, 15955 (March 26, 2008).
      ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L 6931
the government suspects the workers of using fraudulent doc-
uments. Rather, they merely indicate that the worker’s earn-
ings were not being properly credited, one explanation of
which is fraudulent SSNs. This falls short of the “positive
information” from the government that was held to provide
constructive notice in Mester and New El Rey and held lack-
ing in Collins. See Collins, 948 F.2d at 554-55. Without more,
the letters did not provide constructive notice of any immigra-
tion violations.

    b.     Employees’ Reactions

   Aramark also maintains that constructive notice resulted
from the fired workers’ reactions to the no-match letters and
Aramark’s directive to return quickly with documents from
the SSA. It argues that it provided the employees a reasonable
time in which to correct their SSN discrepancies, and that
their failure to do so is sufficiently probative of their immigra-
tion status to rise to the level of “constructive notice” that
they were undocumented.

   We disagree. Though the question is a close one, two con-
siderations weigh against a finding of constructive notice
here: (1) the arbitrator’s findings, and (2) the short turn-
around time. Moreover, contrary to the district court’s conclu-
sion, the analysis is unaffected by Aramark’s offer to rehire
any terminated employees who later came forward with
proper documentation.

         (1)   The Arbitrator’s Findings

  [7] First, as we indicated above, the entire inquiry must
proceed in light of the arbitrator’s finding that there was no
“convincing information” that any of the fired workers were
undocumented. The arbitration came down to essentially the
same question that the court must answer here: whether it
could be said that the fired workers were undocumented. The
arbitrator weighed the same evidence that the parties point to,
6932 ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L
and concluded that none of it constituted “convincing infor-
mation” of immigration violations. While it is true that it is
ultimately for the court to determine whether the arbitrator’s
award would violate public policy, Foster Poultry Farms, 74
F.3d at 174, his factual findings are not up for discussion, see,
e.g., Misco, 484 U.S. at 45, and weigh strongly against Ara-
mark’s position. Put simply, it is difficult to conclude that
Aramark had “constructive notice” — meaning “positive
information” — of a fact when there was no “convincing
information” of it.6

        (2)    The Turnaround Time

   [8] Second, and related, is the extremely short time period
in which the workers were told they should respond before
they would be fired. Both parties spin the record to some
degree — SEIU says the workers had only three days to
respond, while Aramark stretches the period to 90 days. In
fact, workers were told they had three days from the postmark
of a letter from Aramark to return with further documentation
— either a new social security card, or a “verification form”
from SSA that a new card was being processed. If the worker
returned with the verification form, they would still have to
provide a new card within 90 days.

   This adds up to an extremely demanding policy. The initial
three-day deadline was from the post-mark of the letter from
Aramark, so, given at least one day in the mail, it meant
  6
    Indeed, the arbitrator’s findings completely foreclose Aramark’s reli-
ance on arbitration testimony that “[s]ome employees came in and said
they were not able to provide the proper documentation and asked if they
could work anyways.” The arbitrator excluded this statement as hearsay.
The ruling was erroneous, as a statement from an employee in this context
would be a party admission. Fed. R. Evid. 801(d)(2). Nonetheless, we
must take the facts as found by the arbitrator, and we cannot revisit his
evidentiary rulings. See Misco, 484 U.S. at 40 (“[W]hen the subject matter
of a dispute is arbitrable, ‘procedural’ questions which grow out of the dis-
pute and bear on its final disposition are to be left to the arbitrator.”).
       ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L 6933
workers had at most two days to respond. And in these two
days, the workers were expected to gather information that
would prove to SSA that they were entitled to a social secur-
ity number, perhaps obtain legal representation, and navigate
their way to a SSA office during business hours while still
attending to whatever work and family obligations they had.
It seems entirely possible — even likely — that many of the
Staples Center employees concluded they could not meet the
initial deadline, and then simply stopped trying. Nothing in
the record indicates otherwise, and indeed nothing indicates
that the workers understood beforehand that they would actu-
ally have seven to ten days before their terminations became
effective.7

   [9] Notably, and contrary to Aramark’s contention, its
reverification policy was significantly more accelerated than
the one envisioned by the federal safe harbor regulations
(which, as we mentioned above, were promulgated after the
arbitrator’s ruling in this case and are currently subject to a
preliminary injunction). As currently written, employers
would qualify for the safe-harbor (that is, not be subject to
prosecution on a “constructive knowledge” theory) so long as
they asked the employees to provide further documentation
from the SSA within 90 days of the date the employer
received the no-match letter. See 8 C.F.R. § 274a.1(l)(2)(i)(B).8
  7
     Moreover, Aramark has introduced no evidence to suggest that the
“verification form” workers were instructed to obtain was actually avail-
able from nearby SSA offices. Testimony at the arbitration hearing indi-
cated that not all SSA offices provide receipts that would evidence an
applicant’s request for a new card. So, it is entirely possible that workers
were asked to return with a document that was, in practice, unavailable.
   8
     This 90-day deadline was adopted after staff at the EEOC recom-
mended to DHS that the initial proposal, which would have given only a
60-day deadline, be extended because it did not provided enough time for
employees to “collect, organize, deliver documentation, and perhaps meet
with the relevant federal agency and/or seek legal advice while maintain-
ing their work hours.” Letter from Peggy R. Mastroianni, Associate Legal
Council, EEOC (Aug. 14, 2006), available at http://www.eeoc.gov/foia/
letters/2006/vii_national_immigration.html (last visited June 9, 2008); see
also 71 Fed. Reg. 34,281, 34,285 (June 14, 2006) (proposing Rule with
60-day deadline).
6934 ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L
Nothing requires the employer to demand action of any kind
before 90 days, including any “verification form” indicating
that the employee has contacted SSA. Moreover, even if the
employee cannot resolve the discrepancy within 90 days, the
employer can still qualify for the safe-harbor if it completes
a new Form I-9 for the employee (using documents that do
not depend on the disputed social security number). See id.
§ 274a.1(l)(2)(iii). Had the safe-harbor provision been in
effect, Aramark could easily still have qualified for it when it
fired the Staples Center employees. This weighs strongly
against constructive notice here.

       (3)   The Offer to Rehire

   Perhaps realizing that it had imposed too short a turn-
around time, Aramark told the workers that they would be
rehired at any point if they provided the requested documenta-
tion. Aramark relies heavily on this fact in its appeal, and the
district court found it to weigh heavily in Aramark’s favor,
stating:

    It kind of startled me a little bit. In terms of the situa-
    tion now and that is that none of these employees, as
    I understand it, have provided anything — reconcili-
    ation to show that there’s valid social security num-
    bers, et cetera. What is Aramark supposed to do?
    Keep them on until when?

   [10] With all due respect to the district court, this question
misses the mark. It presupposes that the court, in determining
whether the arbitrator’s award ran specifically counter to pub-
lic policy, could reweigh the evidence of events after the fir-
ings. This was improper: the district court should not have
disturbed the arbitrator’s implicit conclusion that the post-
termination evidence did not constitute “convincing informa-
tion” of immigration violations. See, e.g., Stead Motors, 886
F.2d at 1211.
      ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L 6935
   The Supreme Court addressed a similar situation in Misco.
In that case, a manufacturing employee was fired under a pol-
icy prohibiting possession and consumption of marijuana on
company property. 484 U.S. at 32 & n.2. The employer knew
at the time of firing that the employee (1) had been arrested
for possession of marijuana at his home; and (2) had been
present in someone else’s car in a company lot where mari-
juana was found. See id. at 33. At an arbitration hearing, the
company learned for the first time that police had searched the
fired employee’s own car while it was parked on company
property, and had found marijuana inside. See id. The arbitra-
tor declined to consider this evidence, however, because the
employer did not rely on it as a basis for the discharge. Id. at
34. The arbitrator found insufficient evidence that the
employee had violated company policy, and therefore ordered
reinstatement. The employer then sued in district court, which
held that the award of reinstatement violated public policy
concerning intoxicated individuals operating dangerous
machinery. Id. at 34-35. The court of appeals agreed, reason-
ing that the arbitrator should have considered the evidence
that marijuana was found in the employee’s own car on the
company lot. See id.

   The Supreme Court reversed and specifically disavowed
the court of appeals’ reweighing of the facts based on the
post-termination evidence. It held that the arbitrator’s decision
to disregard the evidence was part of his authority to decide
procedural questions arising in the arbitration, which were not
subject to review absent evidence of dishonesty or bad faith.
Id. at 39-40. It also criticized the appellate court for making
a factual inference based on this evidence (that is, that an
employee who had marijuana in his car would, if reinstated,
likely operate dangerous machinery while under the influ-
ence). The court stated:

    [I]t was inappropriate for the Court of Appeals itself
    to draw the necessary inference . . . . The parties did
    not bargain for the facts to be found by a court, but
6936 ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L
      by an arbitrator chosen by them . . . . Nor does the
      fact that it is inquiring into a possible violation of
      public policy excuse a court for doing the arbitrator’s
      task. If additional facts were to be found, the arbitra-
      tor should find them in the course of any further
      effort the Company might have made to discharge
      [the employee] for having had marijuana in his car
      on company premises.

Id. at 44-45.

   [11] Here, similarly, the arbitrator declined to credit the
post-termination evidence — i.e., that the fired employees had
not returned with new social security documents to accept
Aramark’s offer of a rehire. True, the arbitrator did not explic-
itly state whether he viewed the evidence as irrelevant
because Aramark could not have considered it as a basis for
the terminations,9 or whether it was simply unpersuasive
given the variety of potential explanations why the employees
had not returned (for example, advice from the union, the
availability of other jobs, or Aramark’s failure to include an
offer of back-pay). But regardless of whether he deemed the
evidence irrelevant or unpersuasive, under Misco, the courts
cannot second-guess the arbitrator’s findings, even while con-
ducting a public policy inquiry. The arbitrator found no “con-
vincing information” of immigration violations, which
necessarily included any inferences that could have been
drawn from the employees’ failure to later return with docu-
  9
    As SEIU notes, “arbitrators generally hold that a discharge must stand
or fall upon the reason given at the time of discharge; the employer cannot
add other reasons when the case reaches arbitration.” Elkouri & Elkouri,
How Arbitration Works 406 (6th ed. 2003) (citations and quotations omit-
ted); see also Misco, 484 U.S. at 40 n.8 (“Labor arbitrators have stated that
the correctness of a discharge must stand or fall upon the reason given at
the time of discharge, . . . and arbitrators often, but not always, confine
their considerations to the facts known to the employer at the time of the
discharge.” (citations and internal quotation marks omitted)).
       ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L 6937
ments. The district court erred by reweighing this evidence
and substituting its own judgment for that of the arbitrator.

   Moreover, the district court’s approach is problematic
because it suggests that employers could fire employees men-
tioned in no-match letters without providing any time at all
for a correction, since they could always defend themselves
in later proceedings on the ground that employees had still not
come forward with appropriate documentation. This risks
encouraging discriminatory practices in the name of compli-
ance with the IRCA, in direct contravention of this court’s
teachings in Collins.

   One final point. Aramark has introduced no evidence con-
cerning the fired employees’ actual employment status other
than that they were named in the no-match letters and did not
quickly respond to the request for further verification of their
social security status. In addition to creating no “constructive
notice,” this evidence simply does not demonstrate that any of
the workers actually were unauthorized to work, particularly
because a social security card is only one way to prove work
authorization. See Office of Special Counsel, Frequently
Asked Questions, available at http://www.usdoj.gov/crt/osc/
htm/facts.htm#verify (last visited June 9, 2008). Absent evi-
dence that the workers were actually unauthorized, Aramark
would not violate the statute if it reinstated them. 8 U.S.C.
§ 1324a(a)(1) (providing it is unlawful to hire an alien “know-
ing the alien is an unauthorized alien” (emphasis added)); id.
§ 1324a(a)(2) (prohibiting knowing continued employment of
“an unauthorized alien”).

  [12] Accordingly, the public policy against knowing
employment of undocumented workers does not specifically
militate against the arbitrator’s award.10
  10
     SEUI contends that Aramark’s reverification procedures themselves
violated public policy. We need not address this argument. True, an arbi-
tration award that violates some public policies may at times be confirmed
6938 ARAMARK FACILITY SERVS v. SERVICE EMPLOYEES INT’L
                        V.    CONCLUSION

   This case turns on the deference owed to the arbitrator’s
factual findings, as well as the narrowness of both the public
policy exception and the doctrine of constructive knowledge
in the immigration context. Though it seems reasonable to
suspect that some of the fired workers were undocumented,
the law did not permit the district court to rely on this suspi-
cion in vacating the arbitration award.

   We find no issues of material fact and, even viewing the
record in the light most favorable to Aramark, conclude that
SEIU is entitled to judgment as a matter of law. The decision
of the district court is REVERSED and the matter
REMANDED with instructions to confirm the arbitration
award. See Foster Poultry Farms, 74 F.3d at 173 (“An arbi-
tration award must be confirmed as long as the arbitrator is
even arguably construing or applying the contract and acting
within the scope of his authority.” (citations, quotation marks,
and alterations omitted)).




because of countervailing considerations. See Virginia Mason Hosp. v.
Wash. State Nurses Ass’n, 511 F.3d 908, 917 (9th Cir. 2007) (citing E.
Associated Coal Corp. v. United Mine Workers of Am., Dist. 17, 531 U.S.
57 (2000)). But here, we conclude that public policy does not militate
against the arbitrator’s award here, so there is no need to balance compet-
ing interests.
