I will be building some light foundations in the near future and the plans require a pvc coated rigid sleeve through the foundation for connection to a ground rod. This metal sleeve will be required to be bonded on both sides unless I am mistaken? On the accessible, above ground side I can just use a bonding bushing but I am unsure what to use below grade. Is a bonding bushing rated for direct burial, I am having trouble finding any information on this? What are some other options for bonding the conduit below grade?