by Jerry Peck - Codeman on Sat May 15, 2010 6:05 pm
You actually have a double question which you may not even be aware of:
1) The copper water piping system in the house: This must be "bonded" to the ground at the panel, for all intents and purposes for you, this would be the same as "grounding" that copper piping to the ground at the panel. Yes, it the water meter is between two sections of copper pipe, you must "bond" (virtually the same as "ground") around it from metal pipe to metal pipe.
2) The city water service pipe was, I presume (you did not say) previously metal, but it is now plastic. It is possible that your electrical system used the metal water service pipe as a "ground" (if it was metal), however, as the water service pipe is now plastic that will not do any good. That means that you will need to drive two ground rods, making sure they are a minimum of 6 feet apart (there is nothing wrong with them being 10-50-100 feet apart other than using more wire between them, just make sure they are *at least* 6 feet apart). This is based on the extremely limited information you have given, so I am making some presumptions, such as your only "ground" was the metal water service pipe which is now plastic.
You may actually have additional "grounds" and not need the two driven rods, but you did not provide enough information to ascertain that.
If in doubt, have a local licensed and competent electrical contractor come out to your house and verify the electrical system is properly grounded, which means they should measure the resistance to ground, and if they have the equipment for that it would be a good guess that they are indeed "competent".
Jerry Peck - CodeMan
AskCodeMan.com
Construction Litigation Consultant - Retired
Construction and Code Consultant - Semi Retired