If you underwent potty training, you definitely know the process of flushing the toilet, though you probably don't know how toilets work. Like the causes behind airline turbulence, what happens when you flush the toilet is likely something you possess a vague understanding of without getting into the down-and-dirty of it, so to speak. But crazy facts about toilet plumbing exist out there, many happening directly beneath you as you drop a dookie. The mechanics of flushing, including why toilets are u-shaped, only serve to keep you better informed as a citizen, who deserves the right to know where your waste goes.
In this list, you'll learn not only how toilets work, but also how the whole sewage system works and how waste water is cleaned for people not connected to sewer systems. Lucky you! If you ever wondered where stuff goes when you flush it, then check out these fascinating toilet facts and learn how your own human waste connects you to the rest of the world. Bonus points if you read this while on a toilet.
One Simple Flush Sets A Whole Series Of Events Into Action
Once you press or pull that one simple lever on your toilet, a whole bunch of things start happening. First, a chain on the lever lifts up the flapper at the bottom of the top tank (the cistern), causing all the water to drop down to the bowl. The bowl then gets so full of water that the level rises above the S-bend (the pipe coming out the back of the toilet). When the water level pushes past the dip in th S-Bend, it pulls the rest of the bowl's contents with it, sending the waste through the pipes to exit your house or office or Olive Garden.
Meanwhile, that flush also causes another valve to open in the top tank, the inlet valve, which lets water back into the cistern. As the water level rises, a rubber ball attached to the valve rises with it. This causes the valve to close again, and water stops flowing in. Sounds like lot of action, but it's all in a day's work if you're a toilet.
Where Your Waste Goes Depends On Where You Live
After you flush, the pipes from your toilet take your waste on a journey outside your home. But where that journey ends largely depends on the area you live in. If you live in a city or suburb, you're mostly likely connected to the city's sewage system, ending at a wastewater treatment plant somewhere in your metropolitan area. In more rural areas, houses are most likely connected to an underground septic tank buried on the property.
Inorganic Solids Get Separated
Not everything flushed down a toilet is human waste. Other items sometimes make their way down a toilet as well (keys, iPhones, baseball bats, etc). So when your waste and the waste of your neighbors goes through the pipes and gets to the wastewater treatment center, it goes through a series of filters.
First, coarse metal screens keep out larger pieces of inorganic solids, like golf balls, rags, or anything else that shouldn't be flushed in the first place. The water then goes to a grit chamber, where smaller inorganic solids (such as dirt) can be filtered out. Once removed from the wastewater, these pieces usually go to a landfill.
Sludge And Scum Gets Separated
When it arrives at a wastewater treatment plant, the water is filled with a lot of gross stuff, because of course it is. To get rid of that unwanted material, the water goes through a process called "primary clarification."
During this process, the heaviest gunk sinks to the bottom, becoming sludge. At the same time, the lightest gunk rises to the top, which is called scum. Who knew the definitions were so different? Once separated, both the sludge and the scum are more easily removed from the water.