I read the NEC to say that if you use an underground water pipe as your grounding electrode you must suplement it with an addtional electrode which must be less than 25 ohms (250.56). I have only been installing one rod for the suplemental and that has been fine with inspectors, till now. I ran into one that wants two since I can't verify less than 25 ohms. I beleive he is right and have no problem with it but another electrician I know says he is just busting my chops. He seems to think the inspector can not say it is or is not less than 25 ohms thefore no addtional rod is required. What's the real deal. Thanks, Scott

They've been making us use 2 rods for a while around here. It's not that expensive, so I don't see a reason to argue about it, just do it.

One of the towns in my area asks for 2 ground rods. When I ask about it, he threatened to actually bring out test gear to prove me wrong. I put in the 2 rods......like someone said, it's not that expensive and not worth the argument. This is not one of those arguments worth pursuing.

For what it's worth....
We have been enforcing the 2 rods or <25 ohms for a while. You get the occasionsl argument from an EC, but my usual response is

Ground rod testing equipment is about $2000.00. You probably need a day to familiarize yourself with the gear, and some time to perform the test.
A second rod, clamp, wire, is about $20.00

Make it a financial decision.

PS: NJ interpertation of "let the AHJ test it, and prove it's NG" does not fly. The proof of test results is upon the installer, be it the homeowner or the EC.

Nuff said
John