Every house should have at least one plumbing clean out port.
I don't know when they began putting these into houses. It seems to me in the 30s or 40s.
It allows access into the plumbing drain line to clear out a clog in the line inside the house or between the house and sanitary sewer in the street.
In recent decades access ports began to be installed in the yard. This convenience intended that cleaning out the drain might not require a plumber to come into the house and expose the house to sewer gases.
That was a good idea.
Current codes require the ports to be installed indoors and out. The IRC Section 708 has all the definitions regarding that. And there are many!
Coming to a house recently this is what I saw.
The plumbing clean out in the yard was broken, exposing the interior.
I see this from time to time.
Usually it's the plastic drain cap that someone has run over with a lawn mower.
Comparing these two photos, the one on the left is in my yard.
I replaced the cap on mine by inverting it so the knob does not protrude upward.
That way I can mow over it and not worry about breaking and opening it.
But the clean out port in the yard should not be open.
Debris or animals could get inside and clog the drain.
If the cap gets damaged or the port opened it should be repaired. Sooner is better than later.
My recommendation: home ownership requires that even the little things be paid attention to. As to these ports, when they are near the sidewalk and children pass by these holes can become an attractive nuisance whereby dirt, stones, small animals, or even GI Joe or a Transformer could be introduced and clog the line! So keep it sealed!
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560