Sewer Backups

Did you know?

Household sewer blockages can occur at any point in the sewer line, from p-traps attached to a sink or tub drain, to pipes spanning to areas deep inside the sewer line where only a long sewer snake (auger) will reach the backup.


Cause: Pouring hot animal fat down the drain is a major cause of sewer backup. As the grease cools (especially if you pour cold liquid into the drain immediately after the grease), it attaches itself to the walls of the sewer pipe. Other objects flowing down through the drain then stick to the grease, which in turn creates a blockage.

Prevention: Avoid pouring cooking oil and other grease based products into your toilet or drains. Although cooking oil may be liquid when you pour it down your drain, it solidifies after cooling, potentially clogging the main sewer or sewer line. Over time, this may cause your sewer system to back up. Dispose of cooking oil in a heat-safe container.

Tree Roots

Cause: Most sewer lines are made of vitrified clay tile or ductile iron pipes. Over time, the coupling joints can weaken, and the tips of tree roots may push their way into the sewer line in their search for water. When waste travels down the pipe, it becomes caught in the roots and a blockage occurs. Never plant trees with deep roots close to underground sewer lines.

Prevention: Know where your sewer lines run through your yard, and avoid planting shrubs and trees nearby. Seeking moisture, the roots will invade sewer line cracks, continuing to grow until they completely break the sewer lines, causing sewer system backup and damage.

Use a root killer containing copper sulfate to kill the roots of shrubs and trees that have invaded your sewer lines. This can prevent the roots from causing sewer system backup.

Toilet Paper

Cause: When you use too much toilet paper at one time, it can easily become stuck in the toilet bowl's bends or around the closet flange area - the section of the sewer line attached to the floor above which the toilet sits. This scenario tends to occur even more so if the toilet and sewer line are older.

Prevention: Using only an adequate amount of toilet paper is an easy prevention, though the use of an auger can remedy the blockage.

Foreign Objects

Cause: Small foreign objects, such as toy cars or hair pins, can easily flush down toilets or even drop down sink drain holes. Once these objects meet a bend in the sewer line, they become stuck, and sewer waste in turn sticks to the object. With small children in the home, always have locks on toilet lids and keep bathroom doors closed at all times when immediate adult supervision is not possible.

Prevention: Do not flush paper and cloth products down the toilet. Examples of products that you should not flush include paper towels, cloth or disposable diapers, baby wipes, sanitary napkins and certain tampons. These products do not break down the way toilet paper does and can cause an accumulation of debris that clogs the sewer lateral or sewer main.

Avoid pouring dangerous and toxic liquids such as motor oil, epoxies, paint and pesticides down your drain. According to FEMA, these may cause damage and clogging in your sewer line.

Report a sewer backup.