Not all soils are suitable for electrical grounding. It can be impossible to guarantee effective earthing in rocky, sandy, or highly acidic soil. This is why Copper Bonded Earthing Rods were invented! They can better be used in these extremes as well as provide assurance of safety and reliability. Here’s an explanation of why they are the best solution in extreme soil conditions. ... https://www.pioneerpowers.com/copper-bonded-earth-rod.php