*Shallow end, being shocked when grabbing railing*

[Newdude]

Is there a tool that you know of that can dig a 1.5" hole and travel 8' deep

None that are advisable before 811 does it’s thing. After that you can get your power auger on anywhere it’s safe.

 

[mas985]

I think it is safe to go <2' into the soil without 811. All utilities should be more than that and if it isn't, it isn't likely a utility anyway.

 

[Newdude]

I think it is safe to go <2' into the soil without 811. All utilities should be more than that and if it isn't, it isn't likely a utility anyway

+1. Go gentle just because. No jumping on the spade to hammer it home over 15 inches deep

 

[NowintersinAZ]

anchors in the shallow end only had like 50mV AC. The decking over near it was around 1.8VAC. Water was around 2.4VAC, deep end ladder area all registered around 2.6VAC, area at the deep end light was around 2.6VAC as well.

This tells me that the railing is bonded, because it has the closest voltage to the pump. The rest seems to have lost the bond to the railing.

 

[NowintersinAZ]

I think it is safe to go <2' into the soil without 811. All utilities should be more than that and if it isn't, it isn't likely a utility anyway.

You need to be careful with this some of the utilities I have seen less the a few inches below the ground and I have seen cable tv that was laid on the surface of the ground and sodded over.

Also it is with in code to bury a 120v GFCI protected circuit with out a conduit at 12" deep. Granted 811 will not find that as they only cover utilities. It's also code to bury stuff at 18" below the surface. Driving rods at 2' could puncture a pvc conduit.

I would be comfortable stabbing a 8" screwdriver into the ground.

 

[mas985]

My only point here is that anything the screwdriver would hit is not going to be marked by 811 anyway. I really don't think you need to be that deep to get a decent reading. Just do what was done before just in a little different area.

 

[Newdude]

You need to be careful with this some of the utilities I have seen less the a few inches below the ground and I have seen cable tv that was laid on the surface of the ground and sodded over

Any newer CATV or phone lines to the house are usually spaded in just under the grass. You don’t want to cut them because there may be costs to have the company fix them, But you won’t die if you whack one.

 

[Newdude]

* gas and propane have surprisingly shallow requirements as well ‘about 18 deep’ in most jurisdictions.

 

[HeyEng]

* gas and propane have surprisingly shallow requirements as well ‘about 18 deep’ in most jurisdictions.

And irrigation lines can be pretty shallow, too.

 

[JamesW]

I love your thinking.....but that's an 8-foot deep hole I would need to dig Is there a tool that you know of that can dig a 1.5" hole and travel 8' deep?

I would only do it if absolutely necessary.

Let's see what we can find out without the holes.

Partly, I wanted to see what the water table is because that can make it more difficult to find if the bad line is under water.

 

[NowintersinAZ]

It might be worthwhile to dig a few 1.5" holes straight down as deep as the pool to see if you hit water, but don't risk drilling into any lines or pipes.

You can actually get water table information from the ( I believe) county. It gets update periodically. I checked ours at 350-600' depending on where you are.

 

[JamesW]

Yes, they added a retention pond next to my house on the east side.

You can actually get water table information from the ( I believe) county. It gets update periodically. I checked ours at 350-600' depending on where you are.

I don't know that it is always accurate to the specific local area.

It's always better to actually dig a hole to be sure unless you know that the water table is really deep.

Is there a well point under the pool or a dry well?

Did they hit water when digging the pool?

Do we know why the retention pond was added?

Does the pond serve some purpose?

 

[ParB]

What i found mysterious is that the in water voltage gradient seemingly originate from outside the electrical system of the house.
The whole idea of an equipotential bonding grid in pools is to remove the voltage gradient.
How in the world does a stray voltage from a power line find an easier return via water and through a human than through a bonding grid that forms an equipotential grid? The whole idea of forming that grid is that there is low Z measured across any two junctions in the grid vs the high Z of water or a human.

Or is the belief that the grid has failed on the deep end and voltage leaks through the grid? Is that why you want to measure to see if there is voltage gradients in the soil surrounding the pool?

 

[mas985]

Or is the belief that the grid has failed on the deep end and voltage leaks through the grid? Is that why you want to measure to see if there is voltage gradients in the soil surrounding the pool?

Yes and yes. If someone gets shocked, bonding has failed. Since we know it is not due to the house, then it must be outside the house.

 

[NowintersinAZ]

never mind

 

[ParB]

Just trying to summarize (and i'm okay if i'm stating the obvious):
the thesis is that the equipotent bond has failed at/near the area of the pool where the highest voltage gradient is detected, that the voltage gradient is leaking in through the pool water, and that the voltage leak is coming from a source outside the houses electrical system?

To debug this further:
using a soil probe connected to a voltage meter and its other pole connected to the earth bond on the pool pump; to pick up voltage gradient (two feet into the ground was proposed) by probing the ground until you find where the voltage gradient is higher and try to trace it back to its source that way? Its not a bad theory, especially if there is a broken neutral somewhere leaking objectionable current into the soil.

Chances are that if this current has been present for a few years that it has worn out the bond via stray current erosion. At the point in time when the bond fully failed the shocks felt in the pool would have become present.

I would go and get the power company involved. something of this type of leakage through both concrete and water must be a decently sized circuit, unlikely something simple like a cable company moca power distribution system. If you try this yourself with some form of poking in the ground wear rubber boots and rubber gloves for your own safety.

Once the question about where this voltage gradient originates from is answered you still need to revisit the bond. If this voltage gradient is leaking through concrete it really needs to be bonded with a bonding grid, if that has failed per above then you need to fix this even if you find the underlying source of voltage leak.

my few cents.

 

[Newdude]

something of this type of leakage through both concrete and water must be a decently sized circuit, unlikely something simple like a cable company moca power distribution system. If you try this yourself with some form of poking in the ground wear rubber boots and rubber gloves for your own safety.

This type of thing scares the tar out of me. Fine that I can see that it’s only 3 V or 13 V but further down the line it could be Newdude blown to smithereens voltage.

In a way it’s a good thing because it keeps me safe with no shortcuts.

 

[D4T]

The issue: When entering or exiting the pool through the shallow end, and you grab the railing you are feeling like you are being shocked. This is not happening anywhere else in the pool. The deep-end ladder isn't demonstrating this issue.

Info: The pool was built in 2003 and is bonded with a #8 copper wire from the pool motor, over to the four corners of the pool, hand railing anchors in the shallow end, deep end ladder anchors, pool light, and the concrete rebar; it all passed inspection. This issue has never happened until this summer, June 2021.

Testing and isolating: Voltage from the railing to the concrete is about 1.5V and railing to the water is around 1.9V. When we disconnect the ground wire to the house, the voltage drops to .0023V at the railing in the shallow end, and the shock goes away. This is the closest point to the pool motor from where the bonding begins.

We have solar panels on the house. We had them come out to verify that there isn't a voltage leak or grounding issue on their equipment. With all of their equipment unplugged, power off, main breaker to the house turned off, we still had the voltage in the shallow end. Over by the pool motor, we were seeing around 3V on the ground. Absolutely NOTHING was turned on at this moment. All of the solar equipment checked out. The next course of action, check with the power company to see if there's a load issue. They came out, performed a load test, and everything checked out. The house grounding rod is secure and reads 0V. We've taken out breakers, disconnected all of the wires for the pool motor, timer, outdoor outlets, checked the GFCI's. Nothing, absolutely freaking nothing is leading us to the source.

We've never had this problem, but it's only isolated at the railing in the shallow end. I'm planning on removing the railing, cleaning up the bottom section for better contact, then taking a wire brush and running it inside the anchors to see if that helps.

All of the bonding is encased in concrete. However, is there a possibility that the anchor lost its bond? Any insight would be helpful. Thank you!

Sounds like the bonding has come loose. You can check potential with a multimeter. There are some good videos out there for it by Mike Holt.

 

[gamerfan2004]

I don't know that it is always accurate to the specific local area.

It's always better to actually dig a hole to be sure unless you know that the water table is really deep.

Is there a well point under the pool or a dry well?

Did they hit water when digging the pool?

Do we know why the retention pond was added?

Does the pond serve some purpose?

We have tons of clay in this area, and the area under the pool was dry when they built it.

The retention pond, I wish it never existed, but it was added because of the road widening project. I really don't know why it was added, doesn't make much sense unless their intent was to breed mosquitos for testing. It doesn't drain anywhere unless it hits the overflow structure. Before the construction, it was an open flat space.

 

[mas985]

@gamerfan2004 , when the power co cut power to the neighborhood and the shock went away, was that just at the transformer closest to the house? If so, that probably only shut off power to you and your neighbors. The line behind the house at the intersection would most likely be on a different node.