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Why Is Dirty Water Backing up Into Our Bathtub When We Flush the Toilet?

Bathroom with white tile and decorSewage backups are among the worst problems homeowners can face. Slow drains, gurgling noises coming from your bathtub, sewage smells, and sewer water backing up into the tub when flushing the toilet are all warning signs that you have a clog or severe problem in your home's main drain line. When this happens, it’s best to take care of the problem immediately, as sewage can spread illness, disease, and, in some cases, even death.

How can sewer or "dirty water" come through a toilet, bathtub, or sink drain? It’s common for plumbing fixtures in a bathroom to empty or feed into the same main sewer line. Because of that, if there's a blockage somewhere in the sewage line, sewer water can emerge from these main drains.

Sewage line backups can cause problems in your home and cost a lot of money in repairs for the damage. Any time a line or pipe breaks, the potential for water damage to your home’s floors, walls, cabinets, fixtures, and furniture is excellent.

Here Are Some Common Causes of Sewer Backups

  • Tree roots are a big problem. They often grow into pipes, creating cracks or holes.
  • If you have an older home, deteriorated lines or drains can break. Pipe deterioration makes it easier for tree roots, shrubs, or other items to puncture and eventually break lines.
  • A line can become clogged from an overload of toilet paper or other items not meant to be flushed down a toilet.
  • Clogs are also caused by hair, food, grease, soap scum, and other solid materials not meant for a wastewater pipe. More than 90 percent of the time, the reason for a clog is that the line has not been properly maintained or serviced.
  • Sometimes, a city’s sanitary mainline can develop a blockage, and if it isn’t detected in time, sewage can be forced back into your home through the floor drains. This is usually a slow process, allowing you time to call a professional to assess the problem.
  • After a very heavy or large amount of rain, lines can become overloaded and cause a temporary backup.

How do you know when there is a problem with the sewer line? The most common red flags are:

  • Water backing up out of a drain or the toilet plumbing.
  • A gurgling sound coming from the drains.
  • Sometimes, the backup will break the seal under the toilet, and water will show as a leak around the toilet.
  • Slow-flowing drains.

If you think sewage has come in contact with your home’s forced or central air-conditioning system, it's essential to call in a professional for cleanup. Sewage is filled with contaminants, viruses, and bacteria that can cause illness. According to the National Resources Defense Council, nearly two million cases of illness are caused by sewage contamination each year.

You must also have adequate homeowner’s insurance, including sewer backup coverage, in case of damage from a sewer backup. For most insurers, sewer backup coverage is affordable.

If you suspect your plumbing system might be at risk for a sewage backup or have problems with this issue, call a professional plumber to check and service your mainline.

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