1. Many pipes connect to one larger pipe.
2. That larger pipe leads to the sewer.
3. Even outside drains (like by a house or the street) lead to the sewer, too! That's pipes from bathtubs, toilets, since, outside drains, businesses, you name it, it goes to the sewer!
4. The water goes to this place called the wastewater treatment facility.
We're wondering a LOT about that place (and we had a lot of initial questions about how the dirty water is cleaned). Check back soon!