Has anyone experienced this? Quite a few years ago, I was on a microwave relay station/tower site. The site was on nearly solid rock. The specs required that all metal objects were to be bonded to the grounding grid, even the copper screening on the outdoor toilet. Requirements were 25 ohms or less. Unable to obtain this, the EC got some charcoal brickets and crushed them into a powder and poured the powder into the holes where the ground rods were placed in the rock. The system then indicated no resistance over 10 ohms. I still don't understand it.
Rowdy