[quote=Blogstar]With some older houses, grounding to a water pipe was code. after pvc repairs became common that changed. Now the ground rod is used and the water pipes are grounded to that , cold near the house main and the hot water pipe is bonded to cold at the water heater. Thats with copper pipe , with plastic different story.[/quote]That must be really old code. It is probably during the time when everything was galvanized and the watermain was cast iron.. metal connecting everything. I think that when the pipes became copper, things change. You can cause current based copper erosion from galvanic action.
[quote=Blogstar]I believe now, that two ground rods sunk or buried 5′-6′ apart , connected to a continuous solid wire, or a stranded wire in conduit, are required for service mains. Some jurisdictions allow one rod with special testing.[/quote]One house I built, it was 15 feet deep (about 1976). The 5 feet apart sounds familiar. It depends upon how much soil moisture exists. A company I worked in had a hole in the foundation where the grounding rods were driven, more than 5 of them, oriented outwards from center. The hole was to allow inspection of the electrical connections.