I have a new 400 amp service. The water pipe coming in to my house is pvc from the well. The way I understand to ground this service is to install two ground rods 6ft apart and run #6 copper to them. One from each 200amp panel. Do I still need to bond too the copper water lines in the home? Does the rods take care of the primary and secondary grounding?

If this is a new home built under the 2008 NEC you need to connect to the rebar in the footings. This is the only required grounding electrode.

You do still need to bond any other metallic piping systems.

Stan, your advice regarding a Ufer grounding electrode, (concrete encased grounding electrode) as being required must be a regional requirement.

Therefore, Milkman needs to check with his local town, city, county, or state, or perhaps the electric utility, for their requirements of grounding electrodes.

While I agree this is the absolute best electrode, and per NEC 2008 Section 250.50, if it exists, it shall be utilized as an electrode, however, often local authorities recognize that foundations are often installed before an electrician is on site, or even hired.

I dream of a day when residential foundation installers, by order of the building official, is required to leave a grounding electrode conductor that is properly connected to any rebar and a whip of cable is left accessible at every foundation installed.

Here in Maine, the requirement is if the water main is metal pipe 10 feet or more in earth plus a minimum of two eight foot ground rods. If water main is nonmetallic, then only the two rods are necessary, plus bonding to any metal water piping system in the building.

Milkman, check with your local inspector for your regional requirements.


Every commercial foundation here will have the Ufer grounding electrode connected, as these structures will be installed under direction of engineered plans and specifications and general contractors. And electrical contractors are often first on site to install temp power, and/or are hired per contract.

I know of quite a few places that under the 2008 NEC do require rebar to be used if it exists, period

The 2008 change from "if available" to "if present" was a big one. If rebar is present is MUST be used... if the AHJ is one to enforce this rule.
There have been stories on boards like this about guys having to expose & chip away at footings to get at the existing rebar because no one bothered to leave a stub exposed.

The thing about a Ufer is that no supplemental electrodes are required. One Ufer hit and that's it.

I do agree that checking locally is the best answer. This applies to many things.

So who pays for the chipping if the of the concrete to gain access to the rebar, if a whip was not left? Of course, if the EC is hired after he can include that cost in his quote.

Yea, our AHJ's. Including the State inspectors, do not push the ufer ground, esp for residential buildings. Like I said, here all engineered commercial and industrial buildings are done automatically.


I do need to add, and not for your benefit Stan, for other readers, if any other grounding electrode is present, such as a metal water pipe serving the building, that is in earth 10 (ten) feet or more, or building steel.

Keep in mind, a Ufer ground, will only apply if the rebar is bare, zinc, or electrically conductive coated steel. Some rebar is coated to avoid corrosion, and is not conductive, so before anyone just connects a grounding wire to any rebar, be sure what you have.

Back to Milkmans question, what do you mean by primary and secondary grounding?

There is no such thing.