[250.53(D)]. 1, The continuity of the grounding
(bonding) path must not rely on water meters, filtering equipment,
or similar equipment (you can meet this by putting bonding jumpers
around them) and 2, You have to use another grounding electrode with
[250.53(F)]. 30 inches.
[250.53(G)]. At least 8 feet.
[250.53(H)]. 30 inches.
[250.54]. The bonding requirements of 250.50 (or
250.53(C)), and the resistance requirements of 250.56. But that's
because this is supplemental and is not to be used as an
effective ground-fault current path.