What causes a sewer backup?

Sanitary sewer backups can be caused by a number of factors. They usually involve sewer pipe blockages in either the Cityʼs public sewer main lines or in the private sewer service line which the property owner owns and maintains (sewer line between buildings and the Cityʼs public sewer main line). Causes of a backup may include pipe breaks or cracks due to tree roots, system deterioration or improper construction. In home and office plumbing systems, a frequent cause is accumulation of grease, tree roots, hair or other solid materials, such as disposable diapers, baby wipes, sanitary napkins or paper towels that are difficult for wastewater pipes to handle. Such instances may cause major backups in the Cityʼs public sewer main lines as well as in residentsʼ private service lines. Another frequent cause of blockages within the Cityʼs system is intentional dumping of debris into sewer clean outs and manholes. Leaves, sticks, rocks, bricks and trash are sometimes found in manholes.