High on the checklist of experiences no one wishes to have is a sewer back-up or overflow. Fortunately, this experience can usually be avoided by being aware of what triggers back-ups and avoiding those causes. Both primary reasons for drain backups as well as overflows are grease and also roots.
https://zenwriting.net/w1yrmjr183/ewer-maintenance-tipspreventing-sewage-system-line-backup-and-overflowhigh-up