Where does our Poop go?

The content below is from Episode 87 of the Who’d a Thunk It? Podcast


  • I recommend you go out in to the woods and enjoy a book or comic book.
  • Embrace the quiet nature has to offer, clear your mind an. Just read.
  • This past weekend I did just that and I read DC comic’s Dark Nights Metal. It is a comic book about Batman’s worst nightmares coming true and attacking the justice league.


  • Modern plumbing is nothing short of a miracle.
    • We take it for granted and I do mean WE as I myself rarely think about how the unbelievably convenient process that is in-door plumbing makes my life so much easier.
    • We wake up, turn on the faucet to brush out teeth, use the toilet and flush, and then we use the kitchen sink for food prep and sanitation purposes throughout the day.
      • Now I know this isn’t the norm all around the world. Infact, according to the CDC:
        • Globally, more than 785 million people did not have access to at least basic water services in recent years and more than 884 million people did not have safe water to drink.
      • But I personally don’t have any experience with life without convenient water so I can’t say much else about it.
    • For the majority of us, water and plumbing is provided to us at a very cheap cost.
      • Yet the system is so complex it will boggle the mind.
    • For this episode we are going to be tackling a question I’ve had since I was potty trained at the age of 2: What Happens to Our Poop?
      • It should be noted that a lot of organizations and agencies tasked with processing our shit tend to come up with all sorts of different names for it to make their jobs sound less… well… shitty. LOL see if you can count how many different terms are used for Shit during this episode.
        • I’m not going to give you a prize at the end for getting the right number. I just think it is funny how people naturally come up with so many different names for shit.
  • People of the world produce roughly 1,043,000 tonnes (that’s 2,299,421,390 lbs) of crap each day. For the record, that’s approximately 114 Eiffel Towers made of excrement.
    • To explain modern sewage treatment we will be looking at one of the world’s most famouns cities, London.
  • London’s sewage…
    • gets flushed down the toilet, travels through ever-enlarging pipes through a system designed back in the 1800’s by a dude named Sir Joseph Bazalgette.
    • The sewage then enters the Sewage Treatment works in east London. It is the largest sewage treatment plant in Europe.
      • Back in the 1800’s the Brits simply stored all the sewage in tanks and then pumped it out in to the river during high tide to make it the Ocean’s problem. But that is against the law in many countries.
        • Fun Fact: The US banned solid sewage dumping only as far back as 1992. Yeah… not that long ago. Up until then places like New York would take their solid waste about 12 miles out to sea and just dump it… and it would usually just wash right back up on shore lol.
      • Now they treat sewage for a 4 hour process until it is safe enough to return to the watershed system.
      • The Sewage Treatment Works of East London takes on the crap of over 3 and a half million people. It is tasked with processing over 35 olympic swimming pools of sewage ever hour.
      • First, the raw sewage is sent through a large sifter that takes out all the big chunks like paper, bricks, twigs, and any other unsavory debris.
        • This debris is washed and sent to a landfill
          • While looking in to this topic I learned about New York city’s sewage system which is relatviely similar to London’s. Vice’s reporter interviewed someo of the sewage treatment guys who said their rake catches things like cocaine bags, counterfit money, and hospital biohazard bags regularly. *bit of a trigger warning here* But NY’s sewage rake has also caught things like live dogs and as aborted fetuses a few times in the past.
      • Secondly, the sewage is sent to a big tanks where it sits while a large metal contraption the size of a bus essentially works as a rake. It skims the top for any floating material while simultaneously dregding the bottom for heavier material… it is basically a big-ass poop comb.
        • (by now you should know that Organic Material basically means shit)
        • The skimmed and dredged organic material is sent to a filter press where it is dehydrated and incinerated.
          • Incineration is complete combustion, which is the rapid exothermic oxidization of combustible elements in sludge. Dewatered sludge will ignite at temperatures of 420 to 500°C (788 to 932°F) in the presence of oxygen.
          • The London Sewage Treatment Works uses the filtered and incinerated poop (which they call sludge) to power their plant. It provides over 75% of the power needed to keep the Works running.
          • Not all Sewage systems of today incinerate their sludge. Some them use centrifuge technology to separate water molecules from the sludge.
            • They call this centrifuged sludge “cake.” LOL
        • In most modern sewage systems this sludge is examined by scientists with PhD’s. Agencis like the US’s Environmental Protection Agencies make sure there aren’t potentially harmful toxins in our sludge that might cause a pandemic.
          • Nations around the world monitor their own organic material much closer than the average joe realizes.
          • The people in these labs tend to refer to it as “bio solids.”
      • Thirdly, the sewage that is left is taken to another tank where tons of bacteria is added to literally eat away at the organic material left. At the same time, oxygen is pumped in to the tank at the bottom to make sure every part of the sewage is dissolved by the added bacteria. This oxygen accelerates the biological breakdown.
      • And at last the left over sewage is tested to make sure it is safe to return to the Thames river.
  • Now I’d like to give a little tip of the hat to the world’s sanitation workers.
    • You know even during a crisis like 9/11 or Covid-19 our sanitation needs do not stop. And these people don’t do the most desireable jobs.
      • I mean they literally have Shitty jobs.
  • So I’ve talked about how the poop is processed, and I did say where the filtered sewage goes: the filtered and cleaned sewage goes back in to the world’s rivers and oceans… but what about the solids. London uses it to power their sanitation plants (so they claim), but what about the rest of the world?
    • When Vice tried to follow sewage waste in New York from Flush to “Question Mark,” they were met with a lot of secrecy and paranoia. It seemed very few people wanted to answer their simple question of “Where does the poop end up?”
    • They finally got a paranoid trucker to tell them about a company called We Care Organics.
      • This company is paid by the city of New York to take the city’s “bio solids” off their hands. Then We Care Organics takes the bio solids and sells it as fertilizer for farms, large landscaping projects, and even personal gardens.
      • Yup, that’s right. Our shit fertilizes our crops and city flower gardens.
      • And it works out for We Care Organics and companies like them (of which there are lots) because they get paid at both ends. They get paid by municipalities to take shit off their hands AND they get paid by people looking to fertilize and grow plants.
    • I actually knew this. I knew our food was grown with human waste. Well at least some of it is. Some is still fertilized with animal waste. But when I was a kid in junior high I took a bunch of agricultural classes.
      • I grew up in a farming community. Like 25% of the curriculum was “how to be a farmer.”
      • I vaguely remember going to tour a large farm on a class trip and the farmer explaining that he used human waste to fertilize his crops. He even showed our class the giant pile of super filtered and incinerated human shit he used.
        • Our teacher told us not to touch the pile, not because he himself was weirded out by it (no likely used the same kind of fertilizer on his farm at home). No he told us not to touch it out of fear that one of our parents might sue him or something.
        • But by the time he was warning us i had already had a handful of it falling through my fingers. I remember the stuff was brown, cold, and almost like wet dust… but not like mud. It smelled SOOOO much better than the stuff other farmers used like cow and pig shit fertilizer. It just smelled like dirt. I think that is because processing plants and these fertilizing companies are slapped with so many more regulations for their fertilizer than the fertilizer companies that use animal waste.
    • These companies take human shit and turn it in to a treasure that grows our food.
      • They have some of the best PR people on the planet. I’m not kidding. Think about it. They sell human shit to farmers lol.
      • One PR staff at We Care Organics explained that they sell the highest and most sanitized grade of human waste: grade A.
      • His clients swear by the quality of the fertilizer. Apparently it is less acidic than other fertilizers
    • Fun Facts about sewage products:
      • An estimated 10million chinese farmers use raw sewage to fertilize their crops and have been doing so for thousands of years.
      • LOTS of vineyards use biosolids to grow their grapes
      • A ski resort in Arizona uses poop water to make snow
About Biosolids — NEBRA
  • Now there are critics:
    • some scientists pointed out there are chemicals like arsenic and mercury in the fertilizer and that bacteria from pneumonia and encephalitis also lurk in our shit fertilizer.
    • But no studies have show these harmful chemicals and bacteria make it in to the food that it grows. But there have been a limited number of studies on the matter. The scientific community at large hasn’t drawn a conclusion on the matter.
    • Places like Whole Foods has gone public with the fact that they do NOT sell any products grown from bio solids.
      • Also the state of Virginia (one of the US’s biggest Tobacco producers) has warned against using bio solids to grow tobacco… as if they really care about our health lol
  • So what happens to our poop? Where does it go?
    • EVERYWHERE. It is in the food we eat, the flowers we smell, and even the snow we play in.
      • Where did you think it went?
      • We live on just this one big rock afterall. We aren’t shooting it out in to space. It is just like water. Chances are you have drank a glass of water that was once pissed out of Alexander the Great lol.
      • So don’t take life so seriously. It’s all shit anyway…
  • Now I was going to end the episode there, but I had to bring up this little side story I found about another city’s sewage system:
  • While I won’t be going over every major city’s sewage treatment process, I do feel I need to mention Hong Kong’s.
    • Cities like London and New York use treated wastewater for sewage, or desalinated seawater, but Hong Kong is the only large city in the world that has built a whole sewage system around the use of minimally treated water drawn from the sea that surrounds it. It is a remarkable achievement that began back in the 1950s.
    • Hong Kong realized that their old resevoirs were going to become too small as their population increased and their contruction kept cutting in to the resevoir areas.
      • Also, if you know anything about the geo-political climate surrounding Hong Kong, they constructed this modern marvel that is their sewage system to be independent. They are a city isolated from allies up against a hostile mainland that is the Communist Party of China. A mainland that could have held their fresh water hostage.
      • In similar situations places like Israel or Gibraltar have also developed innovative solutions to prevent being held hostage over water supply. Hong Kong came up with the idea of reservoirs built into the sea, wastewater treatment and using seawater for flushing toilets.
    • I bet you didn’t expect that. If you’ve made it this far in my 2nd episode in a row about literal shit, then I bet you didn’t expect to feel all patriotic and proud of democracy over the innovation shown by the Free People of Hong Kong.
Hong Kong's flag: How the bauhinia flower became the target of protest -  CNN Style
  • I don’t mean to diminish the plight of the people of Hong Kong.
    • I actually feel very passionately about their struggle.
    • But I also see the humor in how I started to write an episode about shit and wound up reading an article about Hong Kong’s remarkable sewage system and how that sewage system was a big middle finger to the Community Party of China.
    • and as a tribute to Hong Kong, you beautiful freedom fighters, I’ll end this episode with your song: Glory to Hong Kong!
      • I was going to play the English Version, but I thought the native spoken version would be better. But look up these lyrics. They are badass.


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