fourth year
Unless your drain connects into a manhole, there is no way for them to enter your pipe from the city side. Everywhere is different, but in this area, the usual problem is at the property line where the plumber connected his pipe to the city’s tap lateral. And around here the customer is responsible for the entire line to the main sewer in the street, including replacing the fitting in the main line if it is cracked. Using a camera is the only way to be sure how serious it is.
