Which department is responsible for the demolition of waste water pipes in new houses?

Sewage pipes belong to public facilities, and this part should be maintained by the property.

If it is a city community, it should be managed by the property department. Reason: See the community property management contract.

If you are not in the community, the local urban management should take charge of it (urban zoning management), and some places are called "three guarantees in front of the door". The reason is that they specialize in these things.

If it is in the countryside, the village Committee should be responsible. Reason: Theory of Three Represents Thought is in rural areas, one of which is to represent and serve the people.