how far is that sewer line run, 6 miles? they usually just bore it out and put a PVC sleeve inside. This is done with the cast iron sewer lines, because if they're not properly taken care of, they will rust into nothing and then you just have a suggestion of a hole through the dirt to the sewer line.
my lines are 4" PVC, if we somehow clog those, someone call me an ambulance.
The old shitty clay lines are what you find in most rentals in SoCal. Then one day none of your toilets flushes and the landlord says you flush too many wipes down the toilet. You argue and they make you pay for a plumber who's like "yea they all do that DONT USE WIPES!!!!!One!!!" And then finally after getting to know every other plumber in town, one offers to run a camera for free and shows you that the main line is fucking falling apart and that's why it keeps plugging up.
TBH sewer main inspections should be required any time someone wants to rent a house out.
my lines are 4" PVC, if we somehow clog those, someone call me an ambulance.