Bonding issue in a pool

May 29, 2020
6
Aiken sc
Me and my wife just bought a house. Our main seller was the land (rural area) and the pool. Only 2 weeks in, my wife said the water hurt her and thought it was the chemicals for the pool. Upon closer inspection, it was very clearly a small electrical charge.

I’ve read a lot on this forum about pool bonding and know this is what our issue is, what I’m still not sure about is how exactly to solve this. I know that we need to fix 2 things. 1. Stray current source. 2. Fix the pool bond.

We had an engineer from the local power company come out and test the water initially at around 4.5 volts. They tried a few things and eventually found out that the new cable line that we had run to the house had run their ground line to the companies main ground for the house. They disconnected that ground and the stray voltage went from 4.7 to .7, where we couldn’t feel it anymore. Tonight there was a rainstorm, and I, in my omniscient, decided to reach into the pool water and got s huge shock up my entire arm and a slight burn to my hand.

So my question is, how else can we identify stray currents and their source? And two, how do we fix the bonding issue? We were going to try to run 4-5 bonding rods around the pool and run copper wire connecting them to the pool, water, and attachments as a type of bandaid. And maybe just one ground rod run to a copper metal sheet in the skimmer in the meantime. Would this even work in a bond/ground combo as a quick fix? I’m so lost as to how to solve this issue. The house was built in 1993, and the pool at the same time, plus in a rural area. I can’t imagine the pool is up to current codes as far as bonding goes.
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,864
SW Indiana
Welcome to TFP!

Rods don’t play any part in a bonding system. Bonding is about connecting everything together to create an equipotential system where voltage is the same at every point in and near the pool.

Connecting the grounds from things like cable and telephone service to your electrical ground is fairly important, especially in rural areas. Lightning can play havoc on equipment without a common ground.

A power company engineer is the best first step, but it can often be difficult finding knowledgeable professional help.

Have you determined whether shutting off your main breaker has any effect on the voltage? How close are neighbors? Wells in the area?
 
May 29, 2020
6
Aiken sc
I just wanted a temporary bandaid to ground the water itself in the meantime.

Closest neighbors are probably 200+ yards away. Shutting off the main breaker to the house, and pool breaker had no effect. Everyone has well water out here. Our well is approx. 20 yards from the pool
 

Mdragger88

Bronze Supporter
Jun 1, 2018
1,352
Hernando, Ms
Check out mike holt so you understand the difference in bonding & grounding. There a some informative videos that explain things. Make sure you’re electrician understands pool bonding as some do not.
& no one in the pool till this is sorted!
 

JamesW

TFP Expert
Mar 2, 2011
21,129
We had an engineer from the local power company come out and test the water initially at around 4.5 volts.
See this video here start at 17:00 where they have a live conductor in the water.

They don't even measure 4.5 volts with a live conductor.

If you're really getting 4.5 volts and burns from the current, you have a very serious problem.

Did the seller not say anything?

It would be impossible to not know.

 
  • Like
Reactions: Mdragger88

setsailsoon

Gold Supporter
LifeTime Supporter
TFP Guide
Oct 25, 2015
3,509
Stuart/FL
Sounds like you have several independent indications of a potential ground integrity issue. I would get a competent electrical contractor to test the integrity of your grounding/electrical supply for the pool system. This is not a minor issue and could be dangerous. After a test of the system you should know for certain your grounding system is good or not. The test should be a couple hundred $ or so. The fix depends on your findings and this is not something to Band Aid. Hopefully they just find a wire crossed somewhere. This is coming from an avid DIYer and tinkerer. I will tackle almost anything and "learn as I go" but not on this. Sometimes you have to pay a professional. When you seek out an electrical contractor ask to know their specific experience in ground integrity testing and how they'll do it. Talk to at least 3 contractors. Weight qualifications and experience higher than price in the selection of your contractor.

My $.02 and I hope this works out for you. Please do keep us posted. We all learn from this type of problem.

Chris
 

JamesW

TFP Expert
Mar 2, 2011
21,129
See if you can find the pool permits.

See if you can find the electrical inspector and the electrician who is on the electrical permit to see what they say.

Go talk to the pool builder to see what they know.

The previous owners probably spent considerable time trying to fix this.

Almost definitely, they have contacted several people who tried to fix it. Find those people.

Go to the closest pool companies and ask them if they worked at your address.

The seller probably moved to get away from the dangerous pool.
 
May 29, 2020
6
Aiken sc
The seller never mentioned a problem with the pool. The VA required a pool inspection, but I’m pretty sure the guy we got to inspect it just walked around and made sure everything was in working order/not broken. Funny enough, when we got the local electrical company to come out, they said they remembered the property for prior “shocking incidents” in the past. So definitely a pre-existing issue that wasn’t disclosed to us in the past. He said previously they had installed some sort of box at the nearest power pole (a Grink or something?) and that had seemed to solve the problem, and this time they came out, they tried several things and then finally disconnected the AT&T ground from their main house ground and the voltage went from 4.5 to .7 and they left it disconnected and told us to put a new ground in specifically for the AT&T.

However, the other night in the rain I reached my hand in and legit got an electrical burn, and last night my daughter got another shock and I measured the voltage again at 4.5. Seems to be worse at night, for some reason. We have someone coming in today to do Mike Holt’s fix...hopefully that fixes it. These replies aren’t reassuring though. We literally bought this house for the pool...
 

setsailsoon

Gold Supporter
LifeTime Supporter
TFP Guide
Oct 25, 2015
3,509
Stuart/FL
Michael,

So sorry to hear about this and I am thankful you are sorting this out to be safe. Situations that end in tragedy start where you are and are totally preventable but people in your situation fail to act. Good on you that you're doing this! Please do keep us posted. We'll all learn a lot.

Thanks.

Chris
 

JamesW

TFP Expert
Mar 2, 2011
21,129
At the level you say you're experiencing the shock, there's more going on than a bad bonding grid.

There has to be some serious current running through the area.

Do you have bond wires visible at the equipment pad?

Can you get a multimeter that can measure frequency and measure the frequency of the voltage.

It's just like testing the voltage but with the meter set to frequency.

What is Mike Holt's fix?
 
  • Like
Reactions: borjis
May 29, 2020
6
Aiken sc
At the level you say you're experiencing the shock, there's more going on than a bad bonding grid.
So one issue we fixed was that the internet companies cable connected their ground to the main ground for the house. I’ve tested this and can reproduce the problem. As soon as I make contact from the broadband ground wire to the main house ground, the voltage in the pool went from .8 V to 2.3 V. I’m not sure how or why that happens, but it does. So we disconnected that ground and put it on its own ground.

After that, the water sits around .6 to .8 V. Except at night it still seems to spike up to 4.5 for unknown reasons. I don’t have anything to measure frequency of it. Does that make a difference?

Regarding the pool bonding, when the water was at .7 V the cement was .2 V, so there isn’t a bond between the two. The metal railing on the deep end is bonded to the water, but the bottom screws are matching the cement vpltage potential. To fix that part, I’m still not sure what to do. We’ve been told to remove the metal railings altogether, to rubber paint the cement deck, to diy bonding installments. Like linked below to drill into the skimmer.

 

JamesW

TFP Expert
Mar 2, 2011
21,129
You should get a good "True RMS" multimeter and measure the frequency of the voltage. That can help narrow down the source.

Also, measure the voltage and current AC and DC.
 

sean.a.hyde

Well-known member
Jun 5, 2018
131
Pittsburgh, PA
So one issue we fixed was that the internet companies cable connected their ground to the main ground for the house. I’ve tested this and can reproduce the problem. As soon as I make contact from the broadband ground wire to the main house ground, the voltage in the pool went from .8 V to 2.3 V. I’m not sure how or why that happens, but it does. So we disconnected that ground and put it on its own ground.

After that, the water sits around .6 to .8 V. Except at night it still seems to spike up to 4.5 for unknown reasons. I don’t have anything to measure frequency of it. Does that make a difference?

Regarding the pool bonding, when the water was at .7 V the cement was .2 V, so there isn’t a bond between the two. The metal railing on the deep end is bonded to the water, but the bottom screws are matching the cement vpltage potential. To fix that part, I’m still not sure what to do. We’ve been told to remove the metal railings altogether, to rubber paint the cement deck, to diy bonding installments. Like linked below to drill into the skimmer.

As Mike showed, a difference in measured voltage can be caused by a difference in the current (you're essentially reading the voltage across a resistor: V = I*R). If something is using extra power in the evening, that could be it.
But I agree with everyone that something major is using the ground around your pool as a return path.
 

JamesW

TFP Expert
Mar 2, 2011
21,129
I would contact the seller and ask them what's up with the stray current.

In my opinion, they had a duty to inform you about the problem since they knew about it and it's a major factor in the value of the property.

I would expect them to cover the cost to fix the problem.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
20,474
Northern NJ
There may be a street light or something in the area that turns on at night and creates that current. May be in your house, or a neighbors, or the public streets.

You need to get the guy who found your AT&T ground problem out at night.
 
May 29, 2020
6
Aiken sc
I would contact the seller and ask them what's up with the stray current.

In my opinion, they had a duty to inform you about the problem since they knew about it and it's a major factor in the value of the property.

I would expect them to cover the cost to fix the problem.
Thanks so much for the help everyone. We are in the process of figuring out where the current is coming from. I believe the second source is the light on the power pole about 100 yards from our house. I measured it around .2 V and watched the street light. Right as it turned on the cement to water differential shot to 6 V. Also called our realtor and they suggestion legal action against seller if we can find the date of complaints to the electric company to prove he had undisclosed knowledge of the issue. Hopefully we will have power company come a third time to just disconnect the power pole light (it’s a personal property light pole that we pay for), and then work on bonding the pool.
 
Last edited: