Don't say I didn't warn you... I'm wondering if anyone here can prove to me that Cancun's sewage treatment plants cannot handle toilet paper? I know there are signs in every public bathroom saying don't flush paper. I know that most big hotels here put up signs encouraging people to flush TP. And many hotels have their own sewage treatment (which may or may not flush into the lagoon). I've studied Cancun's sewage treatment a bit (because I have no life). I've learned that there are a number of sewage treatment plants in the city. And the building of a new one was announced in May of this year (Chetumal and Playa del Carmen will be getting new ones as well). I'm not at all sure that all of Cancun's sewage is treated, but when it is treated I've learned that Cancun's sewage treatment is a dual process that separates liquids from solids. Liquids are purified and are injected 120 meters underground into the groundwater (better hope they are really purified). Pause: Remind again why anyone would go into a cenote on purpose? Solids are processed and made into compost. I'm not sure where this compost is used. (How many farms are there around here?) A dual process that separates liquids and solids is a pretty normal model for sewage treatment (from what I've read). What is done with the stuff at the end varies place to place, but what Cancun is doing is pretty normal. Another thing I've learned is that the U.S. Government's Agency for International Development has aided (or is still aiding) this area in making sure that it's sewage treatment is adequate for all the demand here. Here's my problem. Toilet paper is designed to dissolve quickly in water. I owned a house with a septic system and in 11 years of living there never once needed to pump it, the paper dissolved before it built up. And according to my research of all the things that people flush down toilets TP is truly the most minor of culprits. People flush feminine hygiene products and condoms and dead (hopefully small) pets and that's just the beginning. Sewage treatment facilities HAVE to be ready for the bad stuff. I honestly don't think that TP is the culprit that all these signs imply it to be. My Mexican husband says that not flushing TP is cultural. In fact his exact words were "it's a redneck thing." It goes back to before there were any norms about plumbing for sewer. If people's experience is that paper makes the toilet overflow then they won't put it in there and they will put up a sign not to put paper in there. But if they then become indoctrinated to the idea that you can't flush paper they will carry this attitude onward to all the properly working toilets they meet. If the sewer pipes in your house are properly installed (without right-angle corners and with proper slopes, and your toilet is a normal one that is properly installed the paper won't come back up. My husband is a licensed architect (even though you all know he does not work in his field). In college he actually studied Cancun's sewage treatment plants because at that time (back in the stone age) they were the BEST in the country!! Now if a home is not connected to public sewer, if they have a fosa septica (private septic system) and they want to avoid needing to pump their tank then I think it's perfectly fine for them to ask users not to flush TP. But here in the city, where every bathroom I've ever had the good (or often bad) fortune to visit, is connected to public sewer I simply do not believe that there is any reason NOT to flush TP. I want someone to PROVE to me that there is any reality behind the signs we all see in every public restroom. My working theory right now is that all of this is a bunch of B.S. and that people are basically sheep who will believe what they are told. I think that if your particular home's installations are set up correctly that there is no reason whatsoever not to flush TP. Please prove me wrong. And if you don't I've got a great bridge for sale...it's big and I'll sell it really cheap!