Need help to solve a mystery

[Pool-owner]

Dear Pool Experts, I've tearing my hair out for the past few days over this. I can use your collective wisdom here.

Our inground pool has 2 skimmers, 1 main drain and 5 returns. The 2 returns on the steps merged back to one pipe. A few years ago because the pool contractor detected a leak on this pipe, using his pressure gauge. He cut and CAPPED the PVC pipe connected to the filter, and these 2 return jets are closed by plugs on the steps. So far so good.

Recently, we had somebody inspect the pool for a possible sale of the house. After that, I've observed water sipping up from the ground where the CAPPED return pipe was. I noticed that it only leaks when the pump is running.

I suspected that the person might have opened up the step plugs and let water back into the pipe, and since this pipe was leaking before, water is sipping up from the ground where the leak is.

However, it doesn't make sense because it only leaks when the pump is running. This pipe is cut and disconnected from the pump's plumbing - why would the operation of the pump result in water leaking? If I stop the pump, there is no water. Also, there should only be limited amount of water in the capped pipe and leaking should stop soon. But it has continued for a few days already. Not a lot of water but it comes up from the ground when the pump is running. I started digging but haven't found the leaks yet.

Maybe I am wrong. Maybe it is leaking from a connected return pipe (they are close to each other). And water just flew to the capped pipe area underground.

I called some pool companies and they don't seem to be interested in fixing leaking pipes at all. I'll continue digging. But if you have any advice or ideas, kindly let me know.

THANK YOU!

 

[HermanTX]

This appears to be a leak from a functioning pipe. Can you mark what the pipes are in your picture? What is that flexible PVC? What is that pipe that is to the left and in the foreground? In the back ground the pipe is marked Closed skimmer so that must be on the suction side. If the pipe to the right is capped and the opposite end is at the pool return which are also capped then that would not be your leak path when pump running - unless there is a connection to the pipe from another return underground. So you must dig down to determine that.

 

[Pool-owner]

Hi Herman, Thank you so much for the quick response. I've marked up the photo.
- Red is the capped return pipe
- Blue is the working return pipes
- Green area is the suction pipes
- Flexible pipe is the drain pipe connected to the spider valves.

Yes, I agree that it should come from a functioning pipe. It is just that water seems to be coming up from the Red capped pipe when I turn on the pump. Digging is not easy because of the overcrowding, tree roots, small working area. But I will continue digging.

Yes, I also suspected that the capped pipe might somehow be connected underground with the other two return pipes, although it does not really make sense.

Thanks!

 

[HermanTX]

Hi Herman, Thank you so much for the quick response. I've marked up the photo.
- Red is the capped return pipe
- Blue is the working return pipes
- Green area is the suction pipes
- Flexible pipe is the drain pipe connected to the spider valves.

Yes, I agree that it should come from a functioning pipe. It is just that water seems to be coming up from the Red capped pipe when I turn on the pump. Digging is not easy because of the overcrowding, tree roots, small working area. But I will continue digging.

Yes, I also suspected that the capped pipe might somehow be connected underground with the other two return pipes, although it does not really make sense.

Thanks!

Thanks for update. You have 2 return pipes - one on either side of the 3-way valve. Does the other go to a spa return or another set of returns to the pool? the reason I ask is that the valve is open to both pipes. You could fully close either of the pipes by rotating the valve and then turn on pump. Then turn off pump, rotate 180 deg and start pump again. This will determine which side of that 3-way valve may be the issue.

 

[Pool-owner]

Yes, good idea. I'll try that.
The two remaining return pipes are used for 3 other returns in the pool, with one connected to 2 and 1 to 1 I believe. No spas.
So I can test them in turn.

 

[Pool-owner]

Herman and folks, just wanted to report back. We identified the return line that is leaking by closing out the valve and also plugging in the returns. Leak has stopped but right now we have one return line working.
It will need some major digging to get to the leak (most likely the T connectors). I have been calling around for repair services. It seems like the pool companies either do not have the man power to do it, or are not interested in such repairs. If anybody knows anybody or company in Central Jersey who can perform just repairs, please send us referrals. Thank you!