Last weekend I had a little daylight left one day and remembered that I wanted to locate the soil pipe clean-out that I had inadvertently covered up. It leads from an outbuilding, a separate garage. I knew that it needed some fixing of some sort as well. The history is that when our pre-purchase house inspection was done, the video plumbing inspection guys told me that they could not find a clean out. (The area pictured was HEAVILY covered with vine weeds.) They cold not the get the camera into the vent because it terminates inside the garage attic too near the roof deck. They reported that they could see waste water running from the garage into the main soil pipe for the property when the sink was run or the toilet was flushed.

Eventually, I cleared the weeds and found the sunken clean-out. I am planning on regrading the back yard so I wanted to find this and mark or cover it with a bucket. I expected to look into the clean-out and be able to see water running through the pipe after flushing the toilet or running the sink tap. What I found is pictured but with a plastic flower pot stuck in the opening. The opening leads to what initially looked like a through passage, but I could see no water running in it. Water will run into the pipe in both directions from a garden hose. What it looks like I might have is an inverted V-shape that leads to the drain pipe in both directions from that opening. That would be a very short distance to the garage and maybe 30 yards to the corner of the house where it would join other soil pipes from the house.

What you see in the big picture picture:

Horizontal pipe runs from the sink and joins the vertical pipe that is also the vent. The toilet is attached to the slab and is just to the left of the vertical pipe. The vertical pipe runs through the eves and into the attic.

Questions:

Is this really a clean-out and is it a typical way to do that?

Is this whole set-up proper, FUBAR or something in between?

What, if anything, can I, or should I do to properly stopper up the "clean-out" or get it closer to the surface?

Thanks for reading!