How come all sewers don’t stink?

Question

Sometimes ones in the city do. But like, why not all sewers? Do the good ones have valves that hold all the poop and pee back?

In: 0

Answer 1

As mentioned already, the toilet but also water sinks have a trap which avoids this. The waste water line needs to have a venting line to the roof which prevents that another trap gets sucked empty by flushing. It may also stink if the water in a trap gets evaporated over long time .