Rick:
You mention treated wood (4x4 I guess). Arlington Mfg makes a composite item (like a 4x4) that accepts strut straps to secure conduit. Maybe you could work out a deal with the plumbing contractor, and mount the water and elec. conduits like that. Or, how about a concrete/masonry block??
You also could get away from the "float" problem with the masonry block, and RGC conduit. (PVC coated for the salt air). I know you are talking $$$ in material and labor, but you are in a tight position.
John
