A basement bedroom closet built around a sewage pit: what code says about ejector pits in finished rooms

The poster, a carpenter staying at the rental, put it plainly in the title of his Sunday post on r/Construction: he flatly refused to sleep in the bedroom. An ejector is there because the bathroom sits below the sewer line. Fixtures drain into a sealed basin, and a pump lifts the waste up to the building drain, as master plumber Tim Carter of Ask the Builder describes it.

OakSill's summary of IRC section P3007, written by former Virginia and Maryland home inspector Arie Van Tuijl, lists the basics. The sewage pit needs an airtight cover held by screws or bolts and set no more than 2 inches below the finished floor. It must be vented, with pipe at least 1 1/4 inches across, and an air admittance valve does not count. The basin must be at least 18 inches wide and 24 inches deep. The discharge needs a check valve plus a full-open shutoff valve, both reachable above the pit, or under a removable cover where the line is buried, and only fixtures that cannot drain by gravity may go into it.

Carter explains why the vent matters: every gallon the pump moves out has to be replaced by a gallon of air, or the sealed basin pulls a vacuum that can siphon the bathroom's traps dry. He also notes the pumps have moving parts and eventually fail, and swapping one in a basin of raw sewage is work plumbers charge extra for. InterNACHI's inspection narrative library tells home inspectors to write up a basin that is unsealed or loosely covered, missing gaskets, open penetrations, and a vent that is missing, capped or ends indoors. Inspectors are also told to look for staining around the lid. Carpet laid to the edge of the lid covers exactly that spot.