System Grounding

[inspectorwill]

1978 home with a 100 amp service panel. There is only one grounding electrode in the panel at the neutral bus. There are no visible ground rods and all the plumbing was replaced with PVC and CPVC including the main water service line. My concern is that I commonly see the electrical system grounded to the water service line when only one grounding conductor is in the panel. I may be wrong but, if this was a Ufer, I would expect to see an additional bond wire provided for the original metal plumbing. If it is not a ufer, then there is no system ground as the main water service and all piping is now plastic. Any thoughts?

[inspectorwill]

Just to clarify, I speculated the PVC / CPVC plumbing lines were not original. I do not have definitive information but have never seen PVC on original tract construction and the installation was not uniform as I would expect to see if designed with PVC. Although the PVC main is obviously newer.

[Jim Katen]

I think a Ufer ground in 1978 would have been unlikely.

It's very likely the electrical system originally used the metal water main as a grounding electrode. Then someone installed the new plastic pipe and forgot to install a new electrode.

It's a very common oversight.

[Rob Amaral]

Did you see a grounding wire or conduit leaving the exterior meter base box to below the soil outside? Maybe the house is 'grounded' there..

PS-An 'electrode' is a rod or pipe.. you mean 'grounding electrode "Conductor"..

[inspectorwill]

Thanks Jim & Rob. Yes I did mean the grounding electrode conductor and the conductor did not exit the home. The scenario you described Jim is exactly what I expected. Wanted to double check since the ufer was added to the NEC in the late 60s but I'm not sure when and if it was required here.

[Jim Katen]

Thanks Jim & Rob. Yes I did mean the grounding electrode conductor and the conductor did not exit the home. The scenario you described Jim is exactly what I expected. Wanted to double check since the ufer was added to the NEC in the late 60s but I'm not sure when and if it was required here.

It was introduced in the 1968 edition, but only as an alternative to the more common types of electrodes that were common before that.