I have a sump pump that connects to 1.5" PVC. It goes straight up out of the pit about 7 feet, then runs along the ceiling approximately 20 feet to the foundation wall. Just before the wall it bends down 90 degrees, drops about 3 feet, then bends 90 degrees again and exits through the foundation and into the ground.
Problem is, when the pump shuts off, about 20 seconds later there's a very loud gurgling/bubbling noise (sounds like someone rapidly blowing big air bubbles underwater) that comes from the pipe near the foundation wall. It seems to do 5 or 6 "bursts" or rythymic cycles of this noise then stops. I installed another check valve near the wall but it didn't help. How can I stop this?
What's the easiest way to do this? The area next to the foundation is very tight due to a large built-in storage cabinet. The sewer vent pipe is 30 feet or so from the sump pipe. Attaching it outside would involve drilling through the foundation and digging a hole.