How does a water meter affect the continuity of a grounding electrode system when a jumper is present?

Question

250.53(D)(1) Continuity. Continuity of the grounding path or the bonding connection to interior piping shall not rely on water meters or filtering devices and similar equipment.

250.68(C) Grounding Electrode Connections. Grounding electrode conductors and bonding jumpers shall be permitted to be connected at the following locations and used to extend the connection to an electrode(s): [ROP 5–138]
(1) Interior metal water piping located not more than 1.52 m (5 ft) from the point of entrance to the building shall be permitted to be used as a conductor to interconnect electrodes that are part of the grounding electrode system.

With regards to the two above quotes from the NEC 2014, how does the existence of a jumper across the water meter affect the continuity of the grounding electrode system? In particular, my grounding electrode conductor is terminated approximately four and a half feet from the point of entrance of the interior metal water piping to the building (satisfying the five foot requirement), but the water meter is approximately two feet from the point of entrance. I understand that the issue with the water meter is in the event that it needs to be serviced, a path of continuity might be compromised. In my case, this path would still exist due to the existence of a jumper, but does it matter that the jumper is a separate wire from the main grounding electrode conductor?

In other words, do I need to run an entirely new grounding electrode conductor?

Answer 1

The grounding electrode is only required to be 8' and buried 2-1/2' deep for a pipe or rod. The conductor is required to be continuous as you note but you stopped reading prior to the 4 exceptions 250.64.C.1 through 4. But the pipe is the electrode. With many home owners having to replace old galvinised pipe a problem has started when the old pipe is removed and replaced with plastic. I have had to drive new rods where ther was no longer 8' of pipe in the ground. This can cause problems especially if there are no other grounds (driven or Ufer) the most common. If you are concerned about the quality of your ground it is fairly easy to drive a new rod close to your panel and run a #6 copper conductor to the service. Many older homes the water main was the only ground. Adding a driven rod or pipe can only help if located close to the service.

Answer 2

National Electrical Code 2014

Chapter 2 Wiring and Protection

Article 250 Grounding and Bonding

250.52 Grounding Electrodes.

(A) Electrodes Permitted for Grounding.

(1) Metal Underground Water Pipe. A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductor(s) or jumper(s), if installed.

Notice that it says "...electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe)...". As long as the bonding jumper is sized and terminated properly, there should be no problem with this installation.

Electricity doesn't really care if it's a single wire or not, just that it's an adequately sized path. This is why the word conductor is used in the code, instead of wire. If it was called a Grounding Electrode Wire (GEW), then it would likely have to be a single length of wire. Luckily for us it's a Grounding Electrode Conductor (GEC), and so can be any approved object that has an adequately sized electrical path.

Alternatively, you could move the grounding electrode conductor termination, so that it connects to the pipe on the other side of the meter. though you'll still have to leave the jumper in place, so as to bond the interior piping.