My 1895 house has a concrete floor with cast iron drain piping for an old bathroom (sink, toilet, shower, floor drain) in one corner, plus drainage for a sink and washing machine in another corner, with a couple additional floor drains. Everything drains out of the house in one pipe to the septic tank.
The washing machine drain works fine, but the water level in it stays about 6" from the surface. A floor drain about 6' away stays dry, but has quite a bit of sediment in the bottom. I've poured about 20 gallons of water through the floor drain and it all drained with no problem.
I have yet to pour anything through the old bathroom drains.
My questions are how can I test the bathroom drains to ensure they work properly, and how can I flush/clear the sediment out of the drain piping?