Electrical ground in pipe in concrete

Inspected a house where the main electrical panel was grounded to a copper water pipe buried in the cement slab. The water pipe went through the slab and popped up about 6 feet from there across the room where it became part of the city water line entering the home. The problem is a section of the line from that point over to where the city water line came up through the slab was replaced with PEX. Is this still a good electrical ground?

It needs to have solid continuity from the GEC to the ground. So that is a problem.
However, that could be a bonding conductor for the water lines in the home. Was there a GEC coming from the meter, that could have gone to a ground rod as well?

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That is for a Sparky to determine. You did your job. You discovered a potential hazard.
Report what you observed, refer it to a qualified Electrician, and move on.


If the red handle ball valve is the main water shut off then the metal water pipe (if that’s how it comes in, cannot tell from your pic) is not properly used as a grounding electrode.

Meter was mounted on the outside of the house directly behind the main panel. No GEC from meter.

The main water line (copper) enters the house through the slab. It then changes over to PEX for about 4-5 feet, and then back to copper pipe again. The copper pipe goes back down in the slab and comes back up near the electrical panel where the panel ground is attached. So, in reality, there is about 6 feet of copper pipe buried in the cement slab that is acting as a ground.

The water pipe must be in direct contact with earth, not via slab, for 10 or more feet. For the purpose of extending the grounding electrode system, the water pipe must be connected to within 5 feet from where it enters the building. In your case, it means it must be connected to before it continues as PEX, where the orange shutoff is.

It sounds.like the water pipe is not an electrode therefore the metal piping system only requires bonding which can be the connection to the pipe next to the panel. If the metal water pipe is an electrode then the connection must be within 5’ of where it enters the structure as Simon noted.

With the water meter outside is it possible that there is not 10’ of pipe in contact with the earth?