This is in the basement bathroom of a house built in 1964. Is it a valve shut-off or something? The top, although it has a hex nut on it, has a square stem. It's in a corner, about 2 feet from the foundation wall in one direction, and 4 feet from the other foundation wall. There is a cleanout in the slab about 4 feet away, and the standpipe is maybe 7 feet away. The area has a history of plumbing backing up when the soil is saturated (alot of the area is reclaimed wetlands). Has anyone seen this before? Thanks! Julie Click to Enlarge 13.25 KB