# Well casing as electrode?



## goose134 (Nov 12, 2007)

Had a question from someone that I couldn't answer (code book at work). Don't run into this as I live in the big city. Can a metallic well casing be used as a grounding electrode? Guy said he has a 250 foot nickel plated casing. I don't know too much about wells, but it seems like it would be a legit electrode. 
If it is legit, how would you attach the GEC? Cadweld conductor to casing? 
Thanks in advance.


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## socalelect (Nov 14, 2011)

goose134 said:


> Had a question from someone that I couldn't answer (code book at work). Don't run into this as I live in the big city. Can a metallic well casing be used as a grounding electrode? Guy said he has a 250 foot nickel plated casing. I don't know too much about wells, but it seems like it would be a legit electrode.
> If it is legit, how would you attach the GEC? Cadweld conductor to casing?
> Thanks in advance.


The ah j here accepts a box or crimp lug bolted to the casing


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## erics37 (May 7, 2009)

Check out 250.52(A)(8). Yeah, if the well casing is present then it needs to be bonded as an electrode, unless already bonded with a metal water pipe.


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## amptech (Sep 21, 2007)

erics37 said:


> Check out 250.52(A)(8). Yeah, if the well casing is present then it needs to be bonded as an electrode, unless already bonded with a metal water pipe.


Odds are it is not bonded via a metal water pipe. Even if the water line is metal it is probably using a pitless adapter which employs a saddle fitting with a neoprene seal to connect the pipe from the submersible pump to the waterline.


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## erics37 (May 7, 2009)

amptech said:


> Odds are it is not bonded via a metal water pipe. Even if the water line is metal it is probably using a pitless adapter which employs a saddle fitting with a neoprene seal to connect the pipe from the submersible pump to the waterline.


So in other words, more likely than not, the well casing needs to be bonded.


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## goose134 (Nov 12, 2007)

OK, but in lieu of a water pipe from municipal service, could he use the casing as a grounding electrode for the service? 
Unsure whether or not metallic pipe is connecting the well.


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## erics37 (May 7, 2009)

goose134 said:


> OK, but in lieu of a water pipe from municipal service, could he use the casing as a grounding electrode for the service?
> Unsure whether or not metallic pipe is connecting the well.


As far as I can tell in 250.52, if the well casing was the only legitimate grounding electrode available, you can use it without supplemental electrodes. But if it's new construction there's probably a ufer and stuff that would need to be bonded as well.


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## goose134 (Nov 12, 2007)

OK, that is what I recall as well, so it's looking good. This is an existing structure, and I don't think there is a ufer available.


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## erics37 (May 7, 2009)

goose134 said:


> OK, that is what I recall as well, so it's looking good. This is an existing structure, and I don't think there is a ufer available.


Drive some ground rods too if you're nervous about it.


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## goose134 (Nov 12, 2007)

I'm not nervous. I'm serving in a strictly advisory capacity. Thanks for the replies.


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## mbednarik (Oct 10, 2011)

250.50 all grounding electrodes present at EACH BUILDING OR STRUCTURE served shall be bonded together to form the grounding electrode system. Unless the well is at or near a structure, not 200' away, i don't see on how you can say it is required by code, but an option.


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## amptech (Sep 21, 2007)

This isn't really too much of an issue anymore, at least not around this area. 99% of the wells drilled in this area in the last 25 years were drilled with a rotary rig and have PVC well casing. When I built my house in 1988 I found a guy that still drilled wells with a cable driven rig and used steel casing. I was worried about the well being sealed from surface run-off contamination. That being said, I don't have a GEC connected to my well casing but I do have the EGC of the circuit serving the submersible pump(#8) bonded to the well casing.


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## socalelect (Nov 14, 2011)

My well was drilled with a rotary and has steel casing for the first 50 feet then nothing to the bottom. We are in a high rock area


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## Dennis Alwon (May 9, 2009)

The well case only needs to be grounded with the egc from the circuit feeding the pump. You can use it as an electrode back to the service but depending on the distance it may not be a very good electrode because of the impedance to the well casing. I have never seen anyone use it in that capacity.


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## Shockdoc (Mar 4, 2010)

It will make an extremely effective ground source.


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