water tank grounding

shinhyung lee

Saudi Arabia
Hello, we have steel water tanks in our facility in which the material is carbon steel plate (ASTM A36). Concrete foundation is installed for the tank.
Is there international guideline whether to have a grounding for the water tank considerting in following factors?

1. there is lightings in the ladder where lighting power + grouding cable is already installed.
2. there is no instrumentation (i.e RTG), operators are conducting manual reading in periodic basis.

My opinion, there is no need grounding for the tank since it is not hydrocabon storage tanks that we can reference to NEC. The only electrical device is lighting which eqipped on the tank. the lighting has already proper grouding system.

the only case we will need grounding is double protection in case of fault occured in the lighting power circuit and grouding cable was malfuctioning. since the tank foundation (concrete) is not conductive, we will need seperate grouding for the tank to eliminate fault current thru the tank to the ground.

please advise if you know about the subject. thanks in advance.