The fuel tank: good size outdoor tank... its going to hold diesel and it will pump it to some other location to be utilized.
Power: 480 form a pannel in the building will feed a pannel on the tank. From there it hits a xformer and the load side hits another pannel to branch off for many of the controls and pumps.
The problem: we are required to place two grounding plates caddy corner to each other... we were going to bond it to the building counterpoise, but one of the labies said that code changes in the nec require a separately derived ground (2 ground rods 6 feet apart) for fuel tanks
The question: do you have to have a separately derived ground for ground on fuel tank
In my opinion: either way the ground rods would have to be tied in to the building counterpoise and building ground to prevent a differance in potential
Years ago (1990's) I read an NFPA publication (sorry, I can't remember which one) that required AST's (Aboveground Storage Tank) to have a ground rod driven on opposite corners and have the tank grounded to the ground rods. I believe it was strictly for lightning strike dissipation, and not a separately derived grounding system for the electrical circuitry, but I do see where the grounds need to be at the same potential.
I never ran into any local inspection authority that was aware of this recommendation and I never ran into enforcement except on jobs that came through an engineering department that was aware of it.
Also, there is a publication (PEI RP-200) that might address this.