Question: how do u find out all the stuff about how big is the drainpipe and how do they turn it back to clean water (poo) do u love poo

Olivia Bailey answered on 6 Mar 2017:

How big is a drainpipe?
We need to think about how much material is going to go down it and how often – the tricky bit is that people don’t take it in turns to go to the toilet so the amount of water that goes down a pipe is always different! – So it’s a but of clever guess work really! We look at lots of things like what the average person uses, how much it usually rains, how much we should tilt the pipe to make sure the water flows fast enough and add a bit more on for safety!

How do they turn poo into clean water?
when you flush the toilet, the water mixes with all your neighbours water and moves along underground pipes to a Wastewater Treatment Plant – here the dirty water is sent through a few different steps:
1.) A BIG SIEVE: to catch all the things that shouldn’t have been put down the toilet (goldfish, baby wipes, your sisters Barbie)
2.) A BIG POOL: the wastewater is sent to a big swimming pool-like tank where the solid bits sink to the bottom and the water can be take from the top.
3.) BUGS: The water from stage 2 is still not very clean (although now there’s no bits floating in it) so we add some very small and clever bugs that eat all the very small bad bits that are hidden in the water.
4.) BIG POOL no.2: the water is now pretty clean and is sent to another pool where the bugs fall to the bottom of the tank and the water comes off the top.
5.) Sometimes this water is clean enough to be put into a river but if we wanted to drink it then we could put it through a sieve with very, very small holes (this is called a membrane), the holes are so small that they can stop teeny weeny bugs that we cant see from getting through – only the clean water gets through and we can stay hydrated! 😀 clever hey!?