What causes a sewer backup?

Sanitary sewer overflows can be caused by a number of factors. They usually involve sewer pipe blockages in either main sewer lines or service laterals (lines between buildings and the main line). Causes may include pipe breaks or cracks due to tree roots, system deterioration, and insufficient system capacity due to illegal sump pumps, residential or commercial growth, or construction mishaps.


In home and business plumbing systems, the main cause is accumulation of grease, tree roots, hair, or solid materials, such as disposable diapers or sanitary napkins that are too large for wastewater pipes to handle. Such materials may cause major backups in city lines as well as in residents’ lateral lines. Another possible cause of a sewer backup within the city’s system is vandalism. Leaves, sticks, rocks, and trash have been found in manholes. We hope you will report observations of any such activity.

Show All Answers

1. What causes a sewer backup?
2. Is there anything I can do to prevent a sewage backup into my home?
3. How could a sewer backup affect me?
4. What should I do if sewage backs up into my home?
5. If I call the city, what will they do about a sewer backup onto my property?
6. What does the municipality do to prevent this problem?
7. Will insurance cover any damage to my home or property?
8. How and where should I report a sewer backup?