Help identifying a leak

[tysonjm]

Hi All. I have a 15,000gal inground, pebble tech, pool with attached spa. The house is 32 years old but not sure age of pool. It was resurfaced 10 years ago before we purchased the home in 2007.

4 years ago, I noticed an area of grass was slightly mushy all the time (see "A" on photo 1). I figured it was just settling sprinkler water at the low point of our lawn. When I shut off the main irrigation valve for a week however, the wetness didn't go away, so I dug up the grass. What I found is in photo 2 - a broken off 1" PVC pipe extruding from under the concrete. It was dripping water once per minute. At the time, the pool water level seemed fine, and I couldn't see a correlation between the 1" pipe and pool. I buried the mysterious pipe back up again and figured I would solve it later.

Life got busy, and it wasn't until 6 months ago that I noticed dampness in the seem between the edge of the pool deck and outer concrete pad (see "B" on photo 1). A month later, the dampness began to grow, and a shallow puddle appeared 24/7.

During the last 2-3 months, I've run the pump probably only a couple times a week (there's an unrelated reason behind this). A couple weeks ago I started to notice that the water level in the pool was dropping. The bucket test revealed about 1" every 2 days.

It's confirmed that it drops when the pump is not running regularly - and perhaps leaking more the less it runs(?). Also, the spa drops at the same rate as the pool. I've attempted to block inlets/outlets with rubber balls as plugs, but I have not plugged the drain in the pool or spa (Not sure how to determine the type of plugs I need). The concrete under the actual puddle has that kind of 'hallow' sound when you stomp on it.

My questions are: Do I need to still plug the drains if the leak occurs with the pump off, i.e. assume the leak is not on the suction side? Also, is there any way that the mysterious 1" pipe I uncovered, is related to the pool plumbing somehow? What should be my next steps? e.g. do I still need to figure out how to plug every plumbing port properly first?

Thanks for insight/suggestions/questions to help me troubleshoot!

 

[waste]

Welcome to TFP!!

You're doing a good job of identifying the leak. & thanx for the pics.

If, as you say, the leak is lessened by running the pump - you have a suction side leak (skimmers or MDs) Do you get 'extra' air in the pump housing after a few minutes of running the pump?


Have you any idea what the crushed pipe is or what the gray pipe connects to (in pic #2)?

Can you see water flowing into the hole?

Plugging the returns and skimmers isn't hard (and even the spa's MDs oughtn't be too difficult) all you need is an appropriately sized plug (I like to use the rubber winterizing plugs - #8 for 1.5" pipes or #9 for 1.5" threaded pipes, #10 for 2" pipes and # 11 for 2" threaded pipes).

In Pic #2 I see a lot of threaded connections, please check them.

If you need more from me on this - feel free too ask and please post more pics, as needed.

 

[tysonjm]

Hey, thanks for the response! :-D Here's some more info...

If, as you say, the leak is lessened by running the pump - you have a suction side leak (skimmers or MDs) Do you get 'extra' air in the pump housing after a few minutes of running the pump?

Ok, I see what you're saying. Again, this is just in general as I went from running the pump every day for a few hours to just once or twice a week. I seem to always have to clear a little air (filter tank relief valve) after not running for a few days, but I don't notice excessive air bubbles after that (just the typical fast, swirly ones on top in pump housing).

Have you any idea what the crushed pipe is or what the gray pipe connects to (in pic #2)? Can you see water flowing into the hole?

Ok, in photo 2, the broken off 1" pipe coming from under the concrete is the unknown one that leaks. It looks like it could've been an old sprinkler run (but why does it leak!?) The other pipes (dark gray and white) are just for the existing sprinkler lines. I confirmed they weren't leaking when I turned off the irrigation water supply for a week. When I dug that corner up a few years ago, I did not readily see water flow in, but after a day or so, it would fill up as shown in the photo. Again though I never noticed the pool water level going down more than expected...

So it sounds like I need to determine what size plugs I need for returns/skimmers (I guess rubber bouncy balls won't do?!). I'll measure the pipe openings and head to Leslie's(?). Diving for the main drain sounds like it'll be fun, only because I've never done it!

Another question: How could I play around with the valves on the equipment pad to help give me any more clues? I was thinking about this, but I'm not entirely sure I know which pipe is the MD vs. skimmers, etc. See new photo, if you can tell me what Numbers "1, 2 and 3" are that would help! (And honestly, turning them to see what happens did not give results that made sense, e.g. regardless of what I turned on the suction side, the auto-cleaner still had suction all the time, and turning the return valves to pool only still had water going into the spa (very confusing, unless I'm doing something wrong?!)

 

[4knights]

Have you considered attaching a hose to the broken pipe and pushing air through it when everything is turned off? You may be able to see where it goes if it's connected to the pool you should see the bubbles in the pool.
Possibly a pipe that was intended for future water feature or cleaner when pool was built that never got installed and is now leaking?

Or could it possibly be an old sprinkler line that was cut during pool install? (old line tied into an existing one?) I saw a guy install a PVC system that was a loop to help balance the low pressure in all heads.

 

[tysonjm]

Have you considered attaching a hose to the broken pipe and pushing air through it when everything is turned off? You may be able to see where it goes if it's connected to the pool you should see the bubbles in the pool.

Great idea... I shot some air down it w/ the compressor but no sign of any air coming up. I also tried shooting water down it, and I got a little gurgling at the seam where the water is seeping from on the concrete, but nothing in the pool. (Not sure I'm glad or disappointed about that!)