What's a stationary tub? I worked in a house in upstate NY with a similiar setup. The washer emptied into a laundry tub which drained into a pump which pumped it up into the drain for the cesspool. If the pump didn't work, the laundry tub would overflow.
I think the issue would be to make sure the pump was working.
A solution to water backing up through the drain would be to install a backflow device on the drain. Water goes down, but not back up. You would need to break open the floor to get it in place.
Ron
I think the issue would be to make sure the pump was working.
A solution to water backing up through the drain would be to install a backflow device on the drain. Water goes down, but not back up. You would need to break open the floor to get it in place.
Ron