water softener makes noise and water overflows from the ground?

Once in a while, my water softener makes this loud noise for maybe 45 minutes. I am not sure how often it does that since I am not home all the time, but I would say maybe once every other two weeks or once a week. When it does, water starts to overflow from the ground from THE OTHER SIDE of the house. The leaking pipe is outside the house but within my property. I had a plumber come in to investigate, but he wasn't sure the answer when I told him the issue. He dug up the pipe and apparently there's a small extension connected to the pipe and that's where the water overflows out of. Not sure what the purpose was, but he put a cover on top of the extension.



There's no water overflow when the water softener is silent. Yesterday, I was lucky enough to be home when the water softener made that loud noise again, and so I went to the other side of the house and checked on the pipe area, and there it was, water was overflowing out of the extension of the pipe while the water softener was making the loud noise. As soon as the noise stopped, water stopped overflowing out of the pipe on the other side of the house.



So I am 99% certain that the overflow from the pipe on the other side of the house has to do with the water softener, but I can't make heads or tails why it is caused by the water softener, but there's no issue with the pipe when the water softener is silent.



Any comments or thoughts are greatly appreciated!

water softener makes noise and water overflows from the ground?