....Or, perhaps allow the conduit to act as the grounding path? I know the AHJ will have to be involved in the solution, so I want to be prepaired. Any direction as to what section I can reference would be a big help...
Here's the code section and commentary from the handbook. Not to be argumentative with Harry, just to give another perspective, I would not hesitate to use metal conduit as an EGC.
250.118 Types of Equipment Grounding
Conductors
The equipment grounding conductor run with or enclosing
the circuit conductors shall be one or more or a combination
of the following:
(1) A copper, aluminum, or copper-clad aluminum con-
ductor. This conductor shall be solid or stranded; insu-
lated, covered, or bare; and in the form of a wire or a
busbar of any shape.
(2) Rigid metal conduit.
(3) Intermediate metal conduit.
(4) Electrical metallic tubing.
As specified in 250.118(2), rigid metal conduit (RMC) is an
equipment grounding conductor (EGC), and like other metal
raceways such as intermediate metal conduit (IMC) and
electrical metallic tubing (EMT), it can be used as the sole
EGC without a wire-type equipment grounding conductor
having to be installed in the raceway. As a general rule, the
Code only requires one EGC and it can be any of the types
specified in 250.118(1) through (14). There are specific re-
quirements in the Code, such as 517.13(B), where a wire-
type equipment grounding conductor is required regardless
of the wiring method. However, if a wire-type EGC is in-
stalled in a metal raceway and it is not isolated per
250.96(B), the raceway is in parallel with the wire, and the
combination of the metal raceway and the wire is the EGC
for enclosed circuit(s). Exhibit 250.50 illustrates an installa-
tion where RMC is used as the wiring method for feeder
conductors on the load side of the service equipment. The
wireway can also be used as an equipment grounding con-
ductor without a wire-type EGC per 250.118(13).
