When you flush the toilet, the poos and wees go into sewer pipes that are underground.
Then they travel to the filters which trap things that are not poos and wees, such as bottles and Lego.
The poos and wees then are stored in a tank. The heavy feces drop to the bottom of the tank.
Then the sludge is squeezed and the water is pumped out. The water is then cleaned by adding chlorine before it goes back into the sea.
The sludge is put into a pond where the sun's UV rays kill the bad germs. It is also heated up and the bacteria's farts are collected to make electricity for the sewerage system,
The treated sludge is then pumped into trucks to be used as compost in gardens.