What is under this cover?

What is under this cover (to the left of the main water supply).

David and Martha Litton 117.JPG

Radon Mitigation System


Hi Jeffery, It’s not a radon system. My guess is that it has something to do with the plumbing.

Cleanout below the plate?

That’s what I was thinking but one of the houses I died recently had a cleanout in the plumbing above the slab which was right next to this cover. See attached pic of that one.

Kristie and Derek Heeg 118.JPG

Kristie and Derek Heeg 118.JPG

Kristie and Derek Heeg 118.JPG

Clean out or back water valve.

I see these on newer homes maybe 15 years old or less. Jeremy when you say back water valve are you referring to a palmer valve? If so it was my understanding that these were no longer being used in new construction. I don’t always see them so maybe some areas are still requiring them.

A lot of people will have questions for you, did you see the bright light? Anything else we should know about?

If I had did that inspection I would have opened it up to see .

Oops ya got me Erik.
No bright light as a matter of fact I don’t remember a thing! : ) The Bible likens death as a sleep so maybe that’s why I can’t remember.


I did take the cover off of one of them. It was just a hole about a foot deep with gravel at the bottom.

Thus my Radon Mitigation ‘guess’, above. :blank:

Where did the pipe exit to? Was there a fan attached?

No fan. This was the drain plumbing. It wasn’t a mitigation system. I’ve never come across a mitigation system with a metal plate next to it covering a hole. My guess is maybe a palmer valve or a clean out. I will have to talk with a local plumber.

Thank you all!

Have a blessed day.

It could be a covered rough-in box for a plumbing fixture. May have been a change during construction. I could also believe a backwater valve and/or cleanout. Good luck. Let us know what you come up with.