                       FOR PUBLICATION

   UNITED STATES COURT OF APPEALS
        FOR THE NINTH CIRCUIT


 LEOPOLDO PENA MENDOZA;                        No. 17-15221
 JOSE ARMANDO CORTES; ELVIZ
 SANCHEZ,                                        D.C. No.
          Plaintiffs-Appellants,           3:15-cv-05143-WHO

                  v.
                                               ORDER
 FONSECA MCELROY GRINDING                    CERTIFYING
 CO., INC.; GRANITE ROCK                   QUESTION TO THE
 COMPANY,                                    CALIFORNIA
          Defendants-Appellees.            SUPREME COURT



                       Filed January 15, 2019

Before: RAYMOND C. FISHER and MILAN D. SMITH,
 JR., Circuit Judges, and ELAINE E. BUCKLO, * District
                           Judge.

                               Order




    *
      The Honorable Elaine E. Bucklo, United States District Judge for
the Northern District of Illinois, sitting by designation.
2     MENDOZA V. FONSECA MCELROY GRINDING CO.

                          SUMMARY **


                            Labor Law

   The panel certified the following question to the
California Supreme Court:

        Is operating engineers’ offsite “mobilization
        work”—including the transportation to and
        from a public works site of roadwork
        grinding equipment—performed “in the
        execution of [a] contract for public work,”
        Cal. Lab. Code § 1772, such that it entitles
        workers to “not less than the general
        prevailing rate of per diem wages for work of
        a similar character in the locality in which the
        public work is performed” pursuant to
        section 1771 of the California Labor Code?


                              ORDER

    This appeal requires us to resolve whether offsite
mobilization work conducted in connection with a public
works project is performed “in the execution of [a] contract
for public work” such that it entitles workers to prevailing
wages pursuant to the California Labor Code. Cal. Lab.
Code §§ 1771–72. Whether the scope of the prevailing wage
law is expanded or limited, the answer to this question could
have a significant impact on California workers.

    **
       This summary constitutes no part of the opinion of the court. It
has been prepared by court staff for the convenience of the reader.
      MENDOZA V. FONSECA MCELROY GRINDING CO.                    3

    We find no controlling precedent in the decisions of the
California Supreme Court or Courts of Appeal, see Cal. R.
Ct. 8.548(a)(2), and “considerations of comity and
federalism suggest that the court of last resort in California,
rather than our court, should have the opportunity to answer
the question in the first instance.” Busker v. Wabtec Corp.,
903 F.3d 881, 882 (9th Cir. 2018). We therefore respectfully
ask the Supreme Court of California to exercise its discretion
to decide the certified question set forth in Part I of this order.

I. Certified Question

    Pursuant to Rule 8.548 of the California Rules of Court,
we request that the California Supreme Court answer the
following question of state law:

        Is operating engineers’ offsite “mobilization
        work”—including the transportation to and
        from a public works site of roadwork
        grinding equipment—performed “in the
        execution of [a] contract for public work,”
        Cal. Lab. Code § 1772, such that it entitles
        workers to “not less than the general
        prevailing rate of per diem wages for work of
        a similar character in the locality in which the
        public work is performed” pursuant to
        section 1771 of the California Labor Code?

The Court may reformulate our question, and its exposition
of the issues involved should not be limited by the question’s
phrasing. Cal. R. Ct. 8.548(f)(5). We will accept and follow
the Court’s decision. Cal. R. Ct. 8.548(b)(2).
4    MENDOZA V. FONSECA MCELROY GRINDING CO.

II. Background

    Plaintiffs-Appellants Leopoldo Pena Mendoza, Elviz
Sanchez, and Jose Armando Cortes (Plaintiffs) are operating
engineers and members of Operating Engineers Local No. 3.
They worked on grinding crews, using milling equipment to
break up and crush asphalt roadbeds so that new roads could
be constructed. At times, their work duties included what
they referred to as “mobilization” work, which

       entailed loading milling machines, which
       w[ere] stored at [a] permanent yard or in
       offsite storage locations, onto a lowbed
       trailer; tying down or otherwise securing the
       heavy equipment onto the lowbed trailer;
       performing a light, brake, and fluid level
       check of a semi-truck used to transport the
       heavy equipment; driving a transport truck
       transporting the milling machine to a
       construction jobsite; and driving the transport
       truck transporting the milling machine back
       to [the] permanent yard.

As part of this mobilization process, Plaintiffs reported to a
designated yard where the equipment was housed, and then
performed the maintenance and transportation work.
Neither the permanent yard nor the offsite storage locations
depended on any public works project for their existence.

   Defendant-Appellee Fonseca McElroy Grinding Co. Inc.
(FMG), a roadwork construction company, was acquired by
Defendant-Appellee Granite Rock Company (Granite Rock,
and together with FMG, Defendants) in 2014. FMG and
Granite Rock were both signatory parties to the Operating
Engineers Local No. 3 Master Agreement for Northern
California (Master Agreement). In 2010, FMG entered into
      MENDOZA V. FONSECA MCELROY GRINDING CO.                          5

an additional Memorandum of Agreement (MOA) with
Local No. 3, which provided for a “Lowbed Transport” wage
rate for mobilization work; this rate for offsite work was
lower than the Master Agreement rates for onsite
construction. Granite Rock was also a signatory to the
MOA.

    Plaintiffs worked for FMG and then Granite Rock,
including on public works construction projects, and
received compensation based on the Master Agreement and
MOA. Accordingly, although they received a prevailing
wage for onsite construction on public works projects, they
were not paid a prevailing wage for offsite mobilization
work. Plaintiffs estimate that “[t]he ballpark difference
between the two overtime rates in August [] 2012 was
$67.72 (prevailing wage) and $23.89 (lowbed
transportation) for an underpayment of $38.38 in the base
pay.” Defendants note that “[t]he public works contracts
under which Plaintiffs worked did not specify the daily
schedule for Granite Rock’s workers,” and “[t]hus Granite
Rock determined whether [they] would report directly to the
construction jobsite or its yard” and “what tasks, if any,
[they] would perform after completing their jobsite work.” 1

    On November 9, 2015, Mendoza brought claims under
the Fair Labor Standards Act and California labor laws for
nonpayment of wages. Three months later, he, along with
Sanchez and Cortes, filed an amended complaint.

    The parties addressed the dispute that forms the basis of
this appeal through cross-motions for partial summary
judgment, which the district court heard on October 26,

     1
       The contracts for the specific work at issue in this case were not
included in the record before us.
6       MENDOZA V. FONSECA MCELROY GRINDING CO.

2016. On November 28, 2016, the court entered an order in
which it concluded that the offsite mobilization of equipment
was not “in the execution” of a public works contract.
Mendoza v. Fonseca McElroy Grinding Co., No. 15-cv-
05143-WHO, 2016 WL 6947552, at *1 (N.D. Cal. Nov. 28,
2016). Following this determination, the parties settled all
remaining issues, except the dispute now before us.

   A timely appeal to this court followed, raising the
question of California law posed in Part I.

III.      Explanation of Request for Certification

    Under California law, “not less than the general
prevailing rate of per diem wages for work of a similar
character in the locality in which the public work is
performed . . . shall be paid to all workers employed on
public works.” Cal. Lab. Code § 1771. This prevailing
wage requirement applies to “[w]orkers employed by
contractors or subcontractors in the execution of any contract
for public work.” Id. § 1772 (emphasis added).

       The California Supreme Court has explained that

          [t]he overall purpose of the prevailing wage
          law . . . is to benefit and protect employees on
          public works projects. This general objective
          subsumes within it a number of specific
          goals: to protect employees from substandard
          wages that might be paid if contractors could
          recruit labor from distant cheap-labor areas;
          to permit union contractors to compete with
          nonunion contractors; to benefit the public
          through the superior efficiency of well-paid
          employees; and to compensate nonpublic
          employees with higher wages for the absence
     MENDOZA V. FONSECA MCELROY GRINDING CO.                7

       of job security and employment benefits
       enjoyed by public employees.

Lusardi Constr. Co. v. Aubry, 824 P.2d 643, 649 (Cal. 1992).
It has also emphasized that the prevailing wage law should
be construed liberally. City of Long Beach v. Dep’t of Indus.
Relations, 102 P.3d 904, 908 (Cal. 2004).

   On appeal, we are asked to determine whether Plaintiffs
were employed “in the execution of” a public works contract
when they performed offsite mobilization work, including
maintenance and transportation of equipment.

   A. Related Precedent

    We note, as did the district court, that California courts
have not previously addressed the applicability of the
prevailing wage statute to offsite mobilization work
performed by workers employed on public works projects.
See Mendoza, 2016 WL 6947552, at *1. However, the
analytical framework developed in two California Court of
Appeal decisions—Williams v. SnSands Corporation,
67 Cal. Rptr. 3d 606 (Ct. App. 2007), and Sheet Metal
Workers’ International Association, Local 104 v. Duncan,
176 Cal. Rptr. 3d 634, 650 (Ct. App. 2014)—might provide
guidance.

    In Williams, the Court of Appeal addressed whether a
material subcontractor’s truck drivers who hauled materials
away from a public works site were employed “in the
execution of” a public works contract or, like bona fide
material suppliers, were exempt from the prevailing wage
requirement. 67 Cal. Rptr. 3d at 610, 613–14. To resolve
this issue, the court explained that it needed to determine
“the role the transport of the materials plays in the
8       MENDOZA V. FONSECA MCELROY GRINDING CO.

performance or ‘execution’ of the public works contract.”
Id. at 613. It noted that

         [t]he familiar meaning of “execution” is “the
         action of carrying into effect (a plan, design,
         purpose, command, decree, task, etc.);
         accomplishment”; “the act of carrying out or
         putting into effect”; “the act of carrying out
         fully or putting completely into effect, doing
         what is provided or required.” Therefore, the
         use of “execution” in the phrase “in the
         execution of any contract for public work,”
         plainly means the carrying out and
         completion of all provisions of the contract.

Id. at 611 (citations omitted) (first quoting 5 Oxford English
Dictionary 521 (2d ed. 1989); then quoting Black’s Law
Dictionary 405 (8th ed. 2004); and then quoting Webster’s
10th New Collegiate Dictionary 405 (2001)). Borrowing
from a previous material supplier exemption case, O. G.
Sansone Co. v. Dep’t of Transp., 127 Cal. Rptr. 799 (Ct.
App. 1976), 2 the court distilled three factors to consider:
(1) “whether the transport was required to carry out a term
of the public works contract”; (2) “whether the work was

    2
        In O. G. Sansone, the Court of Appeal considered whether two
companies that performed hauling work on a public works contract were
required to pay prevailing wages. 127 Cal. Rptr. at 801–02. The
companies’ employees hauled materials to the public works site from
locations adjacent to the site that were created to serve the project, and
the materials they hauled were identified in the public works contract
and had not been acquired from a “standard commercial supplier.” Id.
at 803. The court held that because the truckers hauled materials from a
project-exclusive site under private agreements that were necessary to
fulfill the terms of the contract, their employer was a subcontractor who
needed to pay the prevailing wage. Id. at 804.
     MENDOZA V. FONSECA MCELROY GRINDING CO.                9

performed on the project site or another site integrally
connected to the project site”; and (3) “whether work that
was performed off the actual construction site was
nevertheless necessary to accomplish or fulfill the contract.”
Williams, 67 Cal. Rptr. 3d at 613. Applying these factors,
the court concluded that the truckers’ off-hauling work was
“unrelated” to the public works contracts and that the
truckers, who were not otherwise employed on the public
works project, fell within the material supplier exemption.
Id. at 614. “In the absence of evidence that, either by
contract or custom, the off-hauling . . . was ‘“an integrated
aspect of the ‘flow’ process of construction,”’” the Williams
court determined that the prevailing wage statute did not
apply to the employees of a material supplier. Id. (quoting
O. G. Sansone, 127 Cal. Rptr. at 804).

    In Sheet Metal Workers, the Court of Appeal reviewed
“whether the prevailing wage law applies to an employee of
a subcontractor who fabricates materials for a public works
project at a permanent offsite manufacturing facility that is
not exclusively dedicated to the project.” 176 Cal. Rptr. 3d
at 637. The court recognized that “the prevailing wage law
is ambiguous concerning its geographic scope. There is no
clear indication the Legislature rejected some geographical
restriction on its application, particularly in the face of
statutes that refer to the site of the work.” Id. at 650. The
court distinguished a hauling case like Williams in light of
this geographic consideration, noting that “hauling activities
necessarily have at least a limited geographical connection
to the public works site,” whereas “offsite fabrication could
theoretically take place anywhere in the world.” Id. at 646.
It further noted that the Department of Industrial Relations
10    MENDOZA V. FONSECA MCELROY GRINDING CO.

(DIR) 3 had previously determined that “fabrication work
performed at a permanent offsite facility not exclusively
dedicated to the public works project is not covered by the
prevailing wage law, whereas fabrication work performed at
a temporary facility that is dedicated to the project is
covered.” Id. at 648. The DIR had explained that “extending
coverage to offsite fabrication would not significantly
protect local labor markets, because fabrication does not
necessarily take place in the local labor market.” Id. at 647.
Applying the analysis from O. G. Sansone, the DIR
concluded that “the sheet metal supplier was exempt from
the prevailing wage requirements as a material supplier
because it was a standard supplier of sheet metal products to
the general public, its facility existed long before the public
works contract, and the facility was not located on or near
the site of the public work.” Id. After considering these
factors and the DIR’s determination, the Sheet Metal
Workers court similarly concluded that “[w]ork performed
at a permanent, offsite, nonexclusive manufacturing facility
does not constitute an integral part of the process of
construction at the site of the public work.” Id. at 650.




     3
       The DIR is charged with “determin[ing] the general prevailing
rate” based on “the applicable wage rates established by collective
bargaining agreements and the rates that may have been predetermined
for federal public works, within the locality and in the nearest labor
market area,” and other factors. Cal. Lab. Code §§ 1770, 1773; see also
State Bldg. & Constr. Trades Council of Cal. v. Duncan, 76 Cal. Rptr.
3d 507, 511–12 (Ct. App. 2008) (reviewing the DIR’s role in wage
determinations). Upon request, it also makes “determination[s] of
whether a specific project or type of work awarded or undertaken by a
political subdivision is a public work.” Cal. Lab. Code § 1773.5(b).
      MENDOZA V. FONSECA MCELROY GRINDING CO.                11

   B. Application to Plaintiffs’ Offsite Mobilization
      Work

    The outcome of this appeal might depend on whether
Williams and Sheet Metal Workers properly apply in this
context. Although neither case is directly on point, both
might be sufficiently analogous to our case such that similar
reasoning should be brought to bear.

     Plaintiffs’ offsite mobilization efforts are at least
partially comparable to the hauling work in Williams and the
fabrication work in Sheet Metal Workers. As with the
latter’s fabrication shop, the offsite yards where Plaintiffs
undertook their mobilization work “do not depend on any
particular public works project for their existence.” Their
work is therefore distinguishable from, for example, the
hauling of materials from sites “located adjacent to and
established exclusively to serve the [public works] project
site.” O. G. Sansone, 127 Cal. Rptr. at 801. The second
Williams factor would thus militate against applying the
prevailing wage law, as Plaintiffs’ mobilization work was
not “performed on [a public works] project site or another
site integrally connected to the project site.” 67 Cal. Rptr.
3d at 613.

    As to the first Williams factor—“whether the transport
was required to carry out a term of the public works
contract,” id. at 613—the record does not provide any such
terms from the contract, and, as the district court noted, there
is “no evidence of the custom or practice of the industry
regarding transportation of heavy equipment to public works
project sites.” Mendoza, 2016 WL 6947552, at *7. Had
Plaintiffs supplied evidence that the offsite mobilization
work was “an integrated aspect of the ‘flow’ process of
construction,” Williams, 67 Cal. Rptr. 3d at 612, then this
case might be more easily resolved. However, no such
12       MENDOZA V. FONSECA MCELROY GRINDING CO.

evidence is presented, either from the terms of the public
works contract or with regards to industry custom. The
contract itself is not included in the record, and although
Plaintiffs requested judicial notice of a variety of materials—
mostly DIR wage determinations for other types of work—
none of these documents relates to the offsite mobilization
of grinding equipment, let alone provides evidence that these
tools, or the work to prepare them, were essential
components of the public works project. 4

    Finally, as to the third Williams factor—“whether work
that was performed off the actual construction site was
nevertheless necessary to accomplish or fulfill the contract,”
id. at 613—the district court observed that California courts
have considered transportation to be integral to public work
in the context of materials, rather than tools. Mendoza, 2016
WL 6947552, at *7. 5 The court determined that a milling

     4
       Rather than rely on such evidence, Plaintiffs instead argue that it
is self-evident that the milling machines were integral to the public works
project because “one can safely say that without the [milling machine]
on site, the job of grinding up the roadbed could not be performed and
the contract executed.”
     5
       Drawing a bright line between materials and tools in this way is
plausible, but not obvious. On the one hand, because materials are
integrated into a jobsite and are not reusable, they are exclusively
devoted to a public works project in a way that tools are not. This
“exclusivity” is an ongoing theme in the relevant case law, as
demonstrated, for example, by the focus on whether an offsite facility
was created for a public works project, or whether a materialman also
sold supplies to the general public. See, e.g., O. G. Sansone, 127 Cal.
Rptr. at 803–04. Tools do not have this inherent characteristic of
exclusivity: the reason for a tool to come and go from a jobsite may be
for its protection or alternative use, which serves the contractor’s
interest, not the interest of the public works project. On the other hand,
the milling machines that Plaintiffs transported constituted a highly
significant component of the public works project on which they were
       MENDOZA V. FONSECA MCELROY GRINDING CO.                          13

machine is “more akin to a tool, not a building material,” and
on that basis distinguished Plaintiffs’ mobilization efforts
from other work that involved “a building material, like
aggregate subbase or asphalt,” and therefore satisfied the
third Williams factor. Id. 6 The court also expressed concern
about a potential slippery slope, pondering whether
Plaintiffs’ “argument could be used to justify application of
the prevailing wage law to the transportation of many things
needed for a public works construction job, such as ‘tools,
portable toilets, generators, potable water, lumber, asphalt,
[and] steel,’” and noting that “[t]he California Court of
Appeal has cautioned against an interpretation under which
‘nearly any activity related to the completion or fulfillment
of a public works contract would be subject to the prevailing
wage law, regardless of where it takes place or whether it
plays a substantial role in the process of construction.’” Id.
at *8 (quoting Sheet Metal Workers, 176 Cal. Rptr. 3d at
642).

   In short, application of the three Williams factors
suggests—albeit not conclusively—that Plaintiffs did not

employed. The heavy equipment was specifically tailored to perform the
type of work required by the project, and unlike other construction tools,
was not widely usable in other contexts. In this sense, the milling
machines might have been “necessary to accomplish or fulfill the
contract” to an even greater degree than common construction tools like
portable toilets or generators, or generic materials like asphalt. Williams,
67 Cal. Rptr. 3d at 613.

    6
      The court cited O. G. Sansone’s discussion of Green v. Jones,
128 N.W.2d 1 (Wis. 1964), in which the Wisconsin Supreme Court
determined that haulers were covered by the prevailing wage law when
they hauled materials that “were dumped or spread directly on the
roadbed and were immediately used in the construction of the project.”
O. G. Sansone, 127 Cal. Rptr. at 804 (citing Green, 128 N.W.2d at 7).
14       MENDOZA V. FONSECA MCELROY GRINDING CO.

perform the offsite mobilization work in the execution of a
public works contract such that the prevailing wage law
applied. 7

    However, other considerations suggest a contrary
conclusion. To begin, the distinctions between Williams and
Sheet Metal Workers and this case are significant. Unlike
the workers in those cases, Plaintiffs performed work on the
public works site that indisputably qualified for the
prevailing wage, leaving us to determine whether work they
performed offsite in connection with those efforts should be
similarly compensated. Whether wage rates for workers
employed on a public works project should vary based on
the task performed is a different inquiry from whether a class

     7
       Additionally, although not controlling, the federal Davis-Bacon
Act provides support for this result. “California courts have turned to
the Davis-Bacon Act for guidance on issues not clearly answered by
California authority.” Sheet Metal Workers, 176 Cal. Rptr. 3d at 649–50
(“[U]nless the Davis-Bacon Act is fundamentally inconsistent with the
portions of the prevailing wage law that one seeks to interpret, the
approach taken under the Davis-Bacon Act may provide useful
guidance.”). The Davis-Bacon Act “plainly imposes a geographical
limitation on the application of the federal prevailing wage law,” id. at
642, as it applies to “mechanics and laborers employed directly on the
site of the work.” 40 U.S.C. § 3142(c)(1). The “site of work” does not
include “permanent home offices, branch plant establishments,
fabrication plants, tool yards, etc., of a contractor or subcontractor whose
location and continuance in operation are determined wholly without
regard to a particular Federal or federally assisted contract or project.”
29 C.F.R. § 5.2(l)(3). The same regulation also specifies that “the
transportation of materials or supplies to or from the site of the work by
employees of the construction contractor or a construction subcontractor
is not ‘construction, prosecution, completion, or repair.’” Id. § 5.2(j)(2).
Accordingly, although the Davis-Bacon Act is not dispositive,
interpreting Plaintiffs’ offsite mobilization work as outside “the
execution of” a public works contract is consistent with the Act’s
guidance.
     MENDOZA V. FONSECA MCELROY GRINDING CO.               15

of employees is sufficiently involved in a public works
project to be considered employed in the execution of a
public works contract, and Williams and Sheet Metal
Workers only addressed the latter issue. Furthermore, the
Court of Appeal’s geographic concern in Sheet Metal
Workers—specifically, that the manufacturing work at issue
there could conceivably have been undertaken anywhere,
and thus did not necessarily implicate the policy concern
underlying the prevailing wage law—is not present here.
Plaintiffs’ mobilization and transportation work was
geographically confined to areas in reasonable proximity to
the public works site. Lastly, whereas Williams involved a
worker with “the status of a bona fide materials supplier,”
67 Cal. Rptr. 3d at 613–14, Plaintiffs directly worked for a
public works contractor, not a materials supplier. These
notable distinctions suggest that Williams and Sheet Metal
Workers might be of limited use in answering the question
that forms the basis of this appeal.

    Additionally, Plaintiffs rely on the DIR’s interpretations
of its Public Works Manual and prevailing wage
determinations, which, they contend, “show that
mobilization is part and parcel of a contractor’s prevailing
wage obligations.” They acknowledge that “a published
determination is not a legal opinion or a position
statement”—a position echoed by the Public Works Manual,
which asserts that it “is not intended as a comprehensive
summary of existing law or duly promulgated regulations”
and “should not be relied upon” to “establish rules of general
application.”     However, “[a]lthough the [DIR] has
determined that its coverage determinations do not have
precedential value, the determinations nonetheless constitute
administrative interpretations entitled to considerable
deference.” Sheet Metal Workers, 176 Cal. Rptr. 3d at 647.
16   MENDOZA V. FONSECA MCELROY GRINDING CO.

    The relevant provision of the Public Works Manual reads
as follows:

       Travel time related to a public works project
       constitutes “hours worked” on the project,
       which is payable at not less than the
       prevailing rate based on the worker’s
       classification, unless the Director’s wage
       determination      for that       classification
       specifically includes a lesser travel time rate.
       (See Director’s Decision in In the Matter of
       Kern Asphalt Paving & Sealing Co., Inc.
       (March 28, 2008), Case No. 04-0117-PWH.
       (See also Morillion v. Royal Packing Co.
       (2000) 22 Cal.4th 575).) Travel time required
       by an employer after a worker reports to the
       first place at which his or her presence is
       required by the employer is compensable
       travel time, and includes travel to a public
       work site, whether from the contractor’s
       yard, shop, another public work site, or a
       private job site. All such compensable travel
       time must be paid at the same prevailing
       wage rate required for the work actually
       performed by the worker at the public works
       site. No additional facts, such as whether
       tools or supplies are being delivered by the
       worker to the site, need be present.

Given that DIR decisions, while not binding, are at the very
least revealing, this provision seems to favor Plaintiffs’
position. This is particularly true because the provision was
undergirded by the DIR’s decision in In re Kern Asphalt
Paving & Sealing Co., No. 04-0117-PWH, in which it
concluded that travel time was compensable at the prevailing
     MENDOZA V. FONSECA MCELROY GRINDING CO.               17

wage for employees’ work on a public jobsite. With regard
to the prevailing wage, the DIR wrote:

       The relevant prevailing wage determinations
       contain no special rate for travel time. In the
       absence of any evidence to the contrary, the
       required travel time must be regarded as
       incidental to the workers’ regular duties and
       payable at the same prevailing rates that
       apply to the classification associated with
       those duties. [The employer] has presented
       no argument or evidence supporting a
       different rate outside of its contention that it
       was not obligated to pay for the travel time at
       all.

(footnote omitted). Although this determination supports
Plaintiffs’ position, DIR determinations must be designated
as precedential in order “to be relied upon in subsequent
determinations,” State Bldg. & Constr. Trades Council of
Cal. v. Duncan, 76 Cal. Rptr. 3d 507, 515 (Ct. App. 2008)
(citing Cal. Gov’t Code § 11425.60), and Kern Asphalt was
not so designated.        See Director’s Prevailing Wage
Enforcement Decisions (Labor Code section 1742) (2007 to
present), Dep’t of Indus. Relations, http://www.dir.ca.gov/o
prl/PrevWageEncDecision.htm (last visited Jan. 7, 2019)
(listing Kern Asphalt among decisions that “have not been
designated precedential and, therefore, . . . cannot be relied
on as authority in future cases”). Nevertheless, the reasoning
and conclusion of Kern Asphalt are instructive, if not
binding, even though the courts bear the ultimate
responsibility for interpreting the statutory language of the
prevailing wage law. See City of Long Beach, 102 P.3d at
910 (“When an administrative agency construes a statute in
adopting a regulation or formulating a policy, the court will
18     MENDOZA V. FONSECA MCELROY GRINDING CO.

respect the agency interpretation as one of several
interpretive tools that may be helpful. In the end, however,
‘[the court] must . . . independently judge the text of the
statute.’” (alterations in original) (quoting Agnew v. State
Bd. of Equalization, 981 P.2d 52, 60 (Cal. 1999))).

      C. Summation

    Ultimately, no California court has addressed whether
offsite mobilization work, performed by workers who are
otherwise employed on a public works project, entitles the
workers to prevailing wages for those efforts. We note that
the various possible outcomes to this question could yield
wide-ranging results. For example, a broader application of
Kern Asphalt might result in an extension of prevailing
wages to a range of public works-adjacent activities,
including mobilization and travel.               Alternatively,
endorsement of the district court’s analysis might limit
prevailing wages only to work that satisfies the factors set
forth by the Court of Appeal in Williams, and thus limit
wages for workers employed on public works projects when
they perform offsite tasks, even when that work is closely
related to their onsite employment. Resolution of this issue
might also implicate, as the district court noted, workers who
haul other equipment to public works sites, from generators
and scaffolding to water and portable toilets.

   Given the potential scope of this decision, its impact on
California workers, and the absence of guiding precedent,
we conclude that certification to the California Supreme
Court of the question presented in Part I is appropriate.

IV.     Administrative Information

   We provide the following information as required by
California Rule of Court 8.548(b)(1).
      MENDOZA V. FONSECA MCELROY GRINDING CO.                19

  The title of this case is: LEOPOLDO PENA
MENDOZA, JOSE ARMANDO CORTES, and ELVIZ
SANCHEZ,    Plaintiffs-Appellants v. FONSECA
MCELROY GRINDING CO., INC and GRANITE ROCK
COMPANY, Defendants-Appellees.

    The case number in our court is 17-15221.

    Plaintiffs-Appellants Leopoldo Pena Mendoza, Jose
Armando Cortes, and Elviz Sanchez are represented by the
following counsel:

    Tomas E. Margain and Huy Ngoc Tran
    Justice at Work Law Group
    84 West Santa Clara Street, Suite 790
    San Jose, California 95113

    Defendants-Appellees Fonseca McElroy Grinding Co.,
Inc. and Granite Rock Company are represented by the
following counsel:

    Paul V. Simpson
    Simpson, Garrity, Innes & Jacuzzi, PC
    601 Gateway Boulevard, Suite 950
    South San Francisco, California 94080

    We designate Leopoldo Pena Mendoza, Jose Armando
Cortes, and Elviz Sanchez as the petitioners if our request
for a decision is granted, as they are the appellants before our
court.

   The clerk of this court shall submit to the California
Supreme Court, under seal of the United States Court of
Appeals for the Ninth Circuit, copies of all relevant briefs
and excerpts of record, as well as an original and ten copies
20    MENDOZA V. FONSECA MCELROY GRINDING CO.

of this order, with a certificate of service on the parties. Cal.
R. Ct. 8.548(c)–(d).

    This case is withdrawn from submission. Further
proceedings before us are stayed pending the California
Supreme Court’s decision. The parties shall notify the clerk
of this court within seven days after the California Supreme
Court accepts or declines this request, and again within
seven days if the California Supreme Court issues a decision.
The panel retains jurisdiction over further proceedings. The
clerk is directed to administratively close this docket,
pending further order.

     IT IS SO ORDERED.
