Joe,
It would really be a total waste to bypass the transformer's excellent isolating properties and the fact that it is now a separately derived source.
While the code calls it an SDS, it is not electrically isolated and can't be if it is installed per code.
The only thing I would tie that ground to might be some primary surge protection for the transformer. My goal for the secondary grounding would obviously be to be at a zero potential difference with the water.
Again, I ask how can that be done and remain in compliance with the code? The primary EGC must be connected to the transformer. The secondary of the transformer is required to be a grounded system. The secondary EGC will also be connected to the transformer case completing the path back to the service grounded conductor.
Don
