I have a sump pump in my basement floor that does what sump pumps are supposed to do. About a foot away from the sump pump pit is a second pit that has no drainage pipes going to it, no connection to the operating pit and it always stays dry with no water in it at all. Basically it’s a sump pump sized pit in the floor that doesn’t have any connection to anything.

My question is, why is that second empty pit there and what is it for? Thanks.

Sounds like a sewage ejector pit.. Your sanitary line to the street must be above the basement floor so the contractor installed the sewage injector pit. It will be necessary to use it if you ever install a bathroom in the basement.

Thanks, that explains it. Our house drain to the sewer looks just like your picture. It exits the basement about five feet up the wall. Basement’s unfinished so no bathroom in it yet.

Depending on the geology in you area, another possibility is that it is rough-in for a radon mitigation system. Quite common in our area of PA. If tests for radon indicate levels of concern, an air pump is installed to pull the air from the stone subbase under your concrete slab, and possibly from subgrade ducting, then exhausts that air outside the house.

For now, put a lid on it and use it for your secret stash.

quote:

Originally posted by zoom6zoom:
For now, put a lid on it and use it for your secret stash.

That's a pretty crappy thing to tell him.

The sewage ejectors I've done have all been in much larger pits than a sump pit. Also, the sewage ejector is self contained completely, while some sumps sit in a bin and others sit in an "open hole" in the floor, or one cast in the foundation.

It's possible it was someone planning for a sewage ejector, or potentially a second or backup sump. Who knows.