Mexican Septic Systems
We promised to explain why you should not put paper in a Mexican toilet, and we’re not going to let you down. There are actually several answers to this question and the most puzzling of these is: you can put paper in a Mexican toilet! Yes, you can. The toilet will not spit the paper back out like a wrinkled dollar from a vending machine. The toilet police won’t show up at your door. And there will be no immediate ill effect from your indiscretion.
But it would be rude.
In many tourist destinations in Mexico, especially hotels, where modern sewage treatment is available, you are encouraged to flush your paper, just like in Gringolandia. The hotel management may even post little signs to let their Mexican guests know that they are expected to dispose of their papel confort down the toilet. They have to do this because Mexicans are trained from birth to be very polite.
But away from the tourist hangouts, and especially in private homes, you will encounter a small, covered, plastic or plastic-lined wastebasket near the toilet. If you see one, then be a polite guest and put your paper in there, not down the toilet.
To understand what etiquette has to do with how you dispose of toilet paper in Mexico, we need a basic understanding of sewer systems. If you are reading this from your home or office in Gringolandia, chances are that your toilet (and anything else that drains from your house) is connected to your city’s public sewer system. Everything you flush flows through large concrete pipes to an industrial processing plant where the solids are separated from the liquids. The liquids are filtered and treated with chemicals and the result is released back into the environment in the least offensive way possible where nature finishes the process using evaporation and rain. The solids are also treated and refined, resulting either in trash or fertilizer. This immense infrastructure is quite expensive to install, operate and maintain. It also consumes a lot of energy. These are your tax dollars at work.
Gringos who flush outside the city limits use a private septic tank, called a fosa septica (septic pit) or sumidero (drain) here in Mexico. In Gringolandia, a septic tank is usually made of a durable plastic and has two chambers, each with a pipe tee inside. The first is the sediment chamber, where the wastewater initially enters. User Plawerth explains the process neatly in his comment:
When waste enters the tank, the paper, poo, and any oils from bathing will float near the surface as a layer known as scum. Over time bacteria will consume nutrients in the scum, and it then settles on the bottom as dense sludge, which is basically inert compost.
When liquid enters the tank, an equal amount of liquid flows out the drain pipe. The tee with its long tube extending down below the surface prevents the floating scum from leaving the tank. The upper part of the tee allows methane and other gases to vent out, while preventing soap foam and lightweight scum above the water line from leaving the tank.
Some scum can still potentially pass, though, which is why there is almost always at least two chambers, and sometimes three chambers, each with a tee on the liquid outlet to restrict scum from leaving the chamber. Usually the first chamber contains most of the sludge and the second and third chambers contain little or no sludge.
If the tank is not cleaned of sludge often enough, eventually it will fill with sludge in all chambers, and then solids will start to leave the tank and plug up the leach field.
A filter on the final outlet will help keep solids that are overflowing out from a poorly maintained septic tank from reaching the drain field, but this needs to be a fine mesh plastic screen or a layer of sand, not just a pile of large loose rocks.
Unlike their northern neighbors, almost all Mexicans use a fosa septica, which is not much different than a Gringolandia septic tank. This technology is very old, so the process is the same. The only difference is the materials. Here in Mexico, many of the colonial houses and other buildings were constructed before the advent of plastics, so most fosa septica are built from plastered stone or concrete block. While plastic septic tanks have one or more manhole covers to permit inspection and cleaning, Mexican fosa septica are generally covered with a slab of concrete and sealed with plaster, like a tomb.
The important difference between a traditional, Mexican fosa septica and a plastic, Gringolandia septic tank is what happens when the clarified liquid is released back into the environment. In the plastic version, the liquid enters one or more perforated PVC pipes, which are buried in long trenches about four feet deep, filled halfway with gravel and covered with topsoil. This is called a drain field, and it’s where you want to plant your strawberries.
In the traditional, Mexican version, the liquid flows down into a filtro (filter), which is a concrete-lined pozo (well) filled with several inches of gravel on top, followed by several inches of charcoal in the middle, followed by a foot or two of sand at the bottom. Why use a filtro and not a drain field? One reason is because the filtro does not use plastics. Another is that this method takes up less space, which is a requirement in colonial urban zones.
But the filtro is the hurdle, so to speak, on the toilet paper trail. Even if much of the paper discarded in a Mexican toilet remains in the fosa septica’s sediment chamber, tiny bits do float past the clarifying chamber and into the filtro, so that over time a paper mache sludge builds up.
How much time does it take to clog a filtro? Nobody knows. It depends on how big the fosa septica and filtro are, how many people are using the toiliet and how much paper or other non-biodegradable stuff they’re flushing down there. It could take three years, or five, or ten. If you don’t flush any paper, it could take fifty or more.
As you probably know, all septic tank systems eventually fill up with sludge and non-biodegradable stuff and have to be pumped out. In Gringolandia, where most septic tanks are located under a lawn in the yard, this is not such a big deal: just dig for a few minutes, screw off the lid and pump away.
In Mexico, maintenance can be a bit more trouble. Many fosa septica are located under the patio, or they might be under the foundation of your house or even partially under your neighbor’s house, because many of these old colonial homes are the result of subdividing a larger mansion. Even when located in a back yard, the access is limited, which means the workers and their hoses will probably be coming through your front door. What’s more, most fosa septica are as old as the houses. Digging into them, like unearthing an ancient tomb, can be risky, leading to cracks or a complete collapse.
This is where famous Mexican thriftiness meets Mexican toilet training. No matter what their socio-economic station in life, Mexicans stretch their pesos and pretty much everything else. When the convenience of flushing paper down the toilet is at the expense of flushing pesos by cracking open a fosa septica, Mexicans would rather have the pesos. In this sense, it would be as rude to flush paper down your host’s toilet in Mexico as it would be to leave the door open on their refrigerator.
Most new homes and residential developments being built in Mexico today do use plastic septic tanks in their construction. When we were working on the design of our new home, we were offered the choice of a plastic septic tank or the traditional fosa septica. The plastic version, called a Septi-K, is billed as an environment-friendly version. It costs less than a fosa septica and has a cover you can remove to rinse the internal filter. The clarified liquids empty into a leach field or French drain. Every ten to 30 months, depending on use, you have to manually remove the lodo (uh... mud), which you can put in your yard as fertilizer or perhaps share with friends. And you can flush paper into it like a gringo.
Hmmm…
When we visit Gringolandia, we now feel uncomfortable putting paper in the toilet. Is it because sorting recyclables by hand is planet-friendly? Is it because it feels like throwing money down the toilet? Or is it just force of habit? Hard to say. In the end, we chose the traditional fosa septica for our new house.
So now you know what to do when you visit our bathroom and why you are doing it. Thanks to you, we may never have to service our fosa septica. At least in this one small way, we have assimilated into Mexican culture.
Comments
CasiYucateco 17 years ago
David,
They are actually trying to help you out. Not knowing that it's done differently in the USA, they don't want to block up your pipes and cause problems. So, while it seems annoying or unclean to us, it means they are trying to do the right thing by you.
How about:
"Ponga el papel usado en el sanitario" (Put used paper into the toilet)
You might add:
"No causará problemas con la tuberia / plomeria" (It won't cause problems with the pipes / plumbing)
You could always have someone explain that there is no problem with putting toilet paper into the toilet in the USA because the pipes are bigger. That's a common belief in Mexico - the paper will clog the pipes. Are there any bilingual employees or friends of theirs? How do you explain what other work must be done by the employees?
As a last resort, simply line the trash can with oversized plastic bags (so there's plenty of clean plastic on the outside) and close up the bags with the contents inside.
(As a side note, you may think this is solely a problem with unskilled or uneducated workers, but we have many programmers in our office from various parts of the world. We're having a problem with this type of situation in our office bathrooms: http://www.healthline.com/blogs/exercise_fitness/2007/01/more-fun-squatting.html Footprints on the seat.)
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David 17 years ago
I always thought it was because of the smaller drain pipes. This helps me understand a bit more.
I found this page through a google search. The reason I was looking, was to find out why our Mexican immigrant employees were throwing their toilet paper in the trash instead of flushing it. Though it may be customary in Mexico, I have no desire to clean that sort of mess up, and they never will take it out.
I have tried removing the trash can which results in used paper on the floor.
I have tried putting up signs in Spanish, but they are ignored. I never was able to pick up much of the Spanish language, so I used Google Translator. I think the Translation is wrong.
Do you have a suggestion for a translation, or another way I can untrain our employees?
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Ray 17 years ago
I've heard that flushing ordinary yeast once a year is also helpful for the septic systems, reinforces the bacterias.
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Ed Palmer 17 years ago
I am a California registered Civil Engineer with experinence in septic system design and installation and many years living in Latin America and Merida. As part of historical home renovations, we are presently repairing or replacing 8 septic systems in Merida.
Assuming that your septic system is properly designed:
1. Your tank should not stink
2. Your tank should accept and digest paper waste
3. You should not put large quantities of bleach and acid in your septic system as is common practice is for cleaning the lime scale and mineral buildup in the Yucatan. Imagine what this would do to your stomach....and the bacteria in the septic tank that break down the solid wastes....
4. ¨Registros¨ are not necessary in most residential waste plumbing systems but clean out plugs are useful. The registros are a common source of bad odors in many Mexican houses patios.
If you have an old system with problems you may have:
1) Old or poorly installed pipe or clay covered channels that do not properly drain and suffer from paper and solids clogging.
2) An improper septic tank installation that does not allow for effluent to escape from the tank as it has become clogged over the years. (Many colonial houses now use the old water supply well as a discharge well for septic system effluent and storm water runoff.)
I completely agree with the other engineer that commented that the plastic tanks offered here are too small. They are good for one to two bedrooms but nothing larger. Their small size guarantees that they will have to be maintained on a regular basis. The plastic tanks must discharge effluent as with any tank and do not reduce contamination of the groundwater. We build concrete, two chamber tanks with double the volume for the same cost. They will require much less maintenance over the life of the system....if any.
These systems are simple, but there are not many people in the region with knowledge of sustainable septic system design. The local systems work but require maintenance and have contaminated the first aquifer below Merida and to the north of the City as evidenced by the Giardia and Ameobic intestinal disease related to the well water in these areas. This too is experience speaking, unfortunately.
A properly designed septic system discharges effluent into a drain field that promotes evapotranspiration or the absorbtion of the effluent water by the topsoil and plants that consume it and evaporate the water into the atmsophere whlie leaving the nutrients in the soil. The extreme rates of absorption of the effluent into the limestone of Yucatan or direct discharge into shallow wells make these easier and more common and unfortunately for the aquifer, accepted solutions. There are choices and this is not a complicated problem if you want to fix it.
Keeping chemicals out of your tank is rule one. Rid X is a septic system enzyme booster product available in the US that is a powder that you flush down the drain to reinforce the necessary bacteria that live in your septic tank....this helps too.
A good article on septic systems if you really what to know more is here: http://www.motherearthnews.com/DIY/1989-03-01/Secrets-of-the-Septoc-System.aspx
If you have a specific problem, I live in Merida and will be glad to listen and give you some ideas as to how to resolve it. Send us an email or get in touch by phone: info@mexsupport.com.mx
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Marco 17 years ago
Just wondering if anyone out there knows the status of the sewage system of Playa del Carmen on the Yucatan. We're condo owners there but can't seem to get a clear answer as to what type of system our building has. It's new--built within the last 2 years, has about 20 units, and is within 500 meters of the Caribbean. Should our guests flush paper or not?
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Suzette 17 years ago
I have a travel trailer parked on a lot in Canada and used to use ordinary toilet paper in it until I saw the difference between it and the biodegradable kind. It is a little more expensive but worth it. Along with that an a sewage treatment chemical I have had no problems with my system clogging. I have also found that Walmart is the cheapest place to by this kind of paper. Thank you for finally answering my question as to why you don't flush toilet paper in Mexico. Now would somebody tell me why so many public washrooms don't have toilet seats? On a humerous note there when I told my husband that I wanted to redo one of our bathrooms in a Mexican style he said oh good then I don't have to pay for a toilet seat.
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Joe Jernigan 17 years ago
I live in Monclova, Coahuila and as it is a fairly large city has public sewer system. I as a gringo see no valid reason for not flushing the paper down the toilet here, but my wife (Mexican) and family still continue to put the used paper in the trash can. I can certainly understand now where the tradition came from, but am at a loss as to how to convince my family that this is definitely not needed (or wanted in my house).
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José Villalobos 17 years ago
Dear Sirs,
I appreciate your orientation about the use of septic tanks in Mérida especially if they are made of plastic which is an optimal alternative for not contaminating the wells.
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Like in Fl? 17 years ago
Well, I grew up in Mexico City, with dreinage in most of the C+ and over homes, and still so I frequently saw waste baskets at the homes of some of my friends. In our home we were educated to flush the toilet paper. My parents considered the idea of "waste baskets" as "very bad habits". They used to say: "this people cannot differentiate between a toilet and a "letrina"". In these days it may sound a comment full of ignorance, but the reality is, that 30 years ago, when I asked the parents of some of my friends why they used a "waste basket" they didn't give me a good explanation other than "is an habit".
By the way, is this the same reason why we shouldn't even think on installing an organic waste disposer in our sink? I know we cannot find any here, but just wondering.
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Per Hörberg 17 years ago
I was googling to find out about the use of septic tanks on pleasure craft (boats) in the US. Apparently such use is compulsory there, as opposed to here in Sweden/Europe, where people keep empting their boat toilets at sea.
I´ll have to keep looking for that info, but in the meantime I´ve learnt a lot. Now some info for you: in Greece, too, all toilet users are urged to use the waste basket for their papers. I always thought this was because the Greek sewage pipes were narrower than in all other countries of Europe. Maybe I´ll have to rethink now... Or perhaps some of your readers want to dig deeper into that issue?
regards, Per H
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Kim 17 years ago
To writer and repliers...
All very informative and I must say, amusing too! I've never seen such an in-depth discussion about the disposal of toilet paper and its effects -- period.
While relatively new to the Yucatan, I definitely learned something worthwhile!
I hope Al comes out to look at the system!
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