I do think this is a legitimate thread. Passengers who do not camp, use RV's, etc. are probably oblivious to the fact that the train's sewage system is any different from their municipal system in what it can handle. Only a few years ago did I become aware that RV's require special toilet paper, for example, as we've never used one. While they probably shouldn't, even on a municipal system, many people are accustomed to flushing baby wipes, tampons, Kleenex, etc. And judging from all the signs in public restrooms, apparently there are problems with flushing paper towels and pads, too.