main panel ground

Hoping for some advice regarding grounding for my main breaker panel. Right now I have a ground wire running from the ground bar in the panel to a brass valve on the water line that runs from the well to the house. From the valve into the house is all copper plumbing, but from the valve to the well is black poly pipe. I've always understood that the reason for using a ground to the plumbing piping was because the piping ran underground to the water main. With a well system and poly pipe between the house and the well, the only connection to the ground would be through the water (?). Is this OK? Should I install a separate ground rod? or 2?
Thanks for any advice- BTW this installation was inspected and passed 22 years ago
according to the sticker on the breaker panel. Thanks, Steve

 

The water service ground is the main grounding electrode for your electrical service. A ground rod is a supplemental electrode. Normally, the water service will be bonded within 5' of where it enters the house. As long it is, then it passes and is OK. Being the service was installed 22 years ago I suspect you already have a ground rod. You will likely find a bare copper #6 wire going outside from the panel.

 

A water pipe known to not be metal exiting the house and running for at least 10 feet underground does not count as a grounding electrode.

Without a water pipe grounding electrode, the ground rod(s) become the main grounding electrode.

This ground wire would count as a bonding jumper to ground the plumbing system with.

It is not an electrical code violation to replace a metal water line with plastic.