PVC Crack on Exposed PVC and Maybe Underground...HELP!

[JoeNC]

A fun couple weeks of very cold weather in NC. Long story short, my freeze protection did not work and I had a frozen pool/frozen PVC pipes/pump/filter, etc. Yesterday, the temperature was 66F and everything thawed out. I was finally able to shut the valves off to prevent the water from leaking out of the return pvc pipe where the exposed crack is. (didn't want to do this before in fear of cracking the valves). I lost about 8 inches of water before I was able to leave work and get home to shut the valves off. The water is now well below the skimmer lines. Now, there appears to be another area where water is pooling up about 12ft from the pool equipment. I am also losing about 1inch of water every 8hrs or so according to my measurements. I haven't repaired the exposed PVC crack yet, but all the valves are shut so no water should be coming from there.

Should I:

1) Drain the pool to stop the leak immediately? (I think this might be safe, but then I can't trouble shoot to find the leak)
2) Start digging and try to repair the PVC pipe underground? How can this be done if the water is still flowing from the main drain? Is there a way to stop this flow or plug the main drain
3) Any other ideas?

 

[Bama Rambler]

If the piping is underground a foot or so, it's unlikely that it has frozen. I can see it freezing at the point of entry and a few inches below the ground. Now if the piping is just barely underground, it could have frozen.

Since it's pooling water away from the equipment, and if the piping is pretty shallow, it may be worth digging around a little and inspecting the piping.

 

[JoeNC]

If there was a leak in the PVC pipe, what would be the average loss per day in inches for a 23k gallon pool? Would the main drain line leak much more than say the return lines due to the increased pressure?

 

[Bama Rambler]

There really is no average loss due to a leak because you never know how big the opening is nor do you know how far below the waterline it is until you've dug it up.

 

[JoeNC]

So I just had a pressure test on my: return line, vacuum line, skimmer lines, and main drain. All of the test passed successfully as each was able to either hold the 20 PSI or pass a buoyancy (?) test. The one cracked pvc pipe was actually still leaking because i have an old Grid Controls valve on the return line. I'm going to cut the PVC return line where the crack is and put a cap on to see if any further water loss occurs.

Should i be comfortable with this pressure test? Are they always accurate in detecting hairline cracks?

 

[Bama Rambler]

If it'll pass a pressure test of a few hours then it's a pretty good indicator that the plumbing isn't leaking.