Your home’s sewer line is out of sight and all too often out of mind – until trouble occurs, that is! Our state-certified master plumbers at CarbonePlumbing know that homeowners especially dread any issue involving sewer pipes. That’s why we’re providing this guide to help you recognize the signs of problems before they become full-blown emergencies, as well as to educate you on the common causes of problems – some of which can be avoided!

What Exactly is a Sewer Line?

New (or relatively new) homeowners may not be clear on what a sewer line exactly is. Considering the name, many people mistakenly believe that since the sewer is a municipal service, the city or appropriate utility agency is responsible for any problems with the sewer line.

Just to be clear, what this refers to is the portion of the sewer line that leads from your house to the main sewer lateral under the street. The homeowner is responsible for repairs when this line becomes clogged, cracks or breaks. It is not to be confused with the municipal sewer line, which is the municipal government’s responsibility to maintain and repair. For homes with a septic system, the sewer line leads to the septic tank.

Common Warning Signs of a Sewer Line Problem

Because of the sewer line’s underground location, problems often can’t be observed directly. Look out for the following warning signs, provided by our colleagues at Carbone Plumbing of Portland, OR:

  • Sewage backup and blockages – Sewage backups can happen every now and then, but if sewage backs up every time you flush the toilet, the problem could be your main sewer line. All of your home’s drains rely on the main line in order to drain properly.
  • Foul odors – Your plumbing should never be stinky. If it’s emitting an unpleasant odor, you should have your system examined.
  • Mold and mildew – These conditions are health hazards and should be addressed immediately, as they can spread rapidly. A crack in your sewer line can leak water and promote their growth, so you should call a professional as soon as possible.
  • Slow drainage Slow drains are a common plumbing problem, and most issues can be easily fixed. When these methods don’t work, however, it could mean that you have a severe clog deeper in your sewer line.
  • Random lush spots in your yard – Have you noticed spots in your yard that are extra green and lush? If so, it could be from a crack in your main line. Sewage is a great fertilizer, so it’s likely a leak directly below.
  • Pests – Rodents and other critters can fit through cracks in your sewer line with ease. From there, they can make it into the rest of your plumbing system and other areas in your home.
  • Foundation damage – Did you know that a problem with your line can cause structural damage in your home? If the source of the leak isn’t addressed, leaking water can cause cracks and even sinkholes in your foundation.

Changes in”> function of your plumbing fixtures can also indicate a sewer line problem. Pay attention if the following occur:


  • Flushing the toilet causes water to back up from your tub or shower.
  • Toilet water starts to bubble. Should this happen, run water in the sink closest to the toilet for a minute or so. If the water continues to bubble (or rises), there’s a problem.
  • Hearing a gurgling noise as the toilet flushes or the water in your bathtub or shower is draining. If you hear this, call a plumber immediately.

Washing machine

When the draining water from your washing machine causes the toilet to overflow or backs up into the tub or shower, it could mean your sewer drain has a problem. However, if the toilets are flushing as usual, the problem could be local and not in your sewer drain.

Common Causes of Sewer Line Problems

So what can go wrong with a sewer line? Some issues can’t be prevented, but others can! Here are the most common causes, provided”> Carbone the Plumber:

Severe pipe damage – When sewer pipes are broken or ruptured, the sewage won’t be able to properly drain through the system, leading to immediate and frequent backups. Common causes of sewer pipe damage include:

  • Sewer pipe rupture due to shifting soil, settling, increased traffic on the ground above or use of heavy construction equipment above ground.
  • Corrosion of an older pipe, causing the pipe to break or collapse.
  • Leaking joints where the seals between sections of pipe have broken, allowing water and sewage to escape.

A sagging sewer line – While this is out of a homeowner’s control, sagging sewer lines happen over time. This “bellied” pipe occurs when a section of the pipe has sunk due to ground or soil conditions. The low spot in the line will begin to collect paper and waste, resulting in repeat blockages.

Tree root infiltration – Older sewer lines were sometimes constructed out of clay or other porous materials. In addition, the connections between the pipe sections weren’t as tight as today’s PVC pipes.

As”>tree and shrub roots grow, they search for sources of water. If they latch onto a sewer pipe, they will grow into the pipe in order to reach the water and nutrients inside. As the roots expand over time, it can cause the line to break. Our blog post – “Are Tree Roots in Your Sewer Line?” – covers this issue in detail.

Flushing debris down the toilet – For the sake of your plumbing system’s health, it’s important to know”>what you can and can’t flush down your toilet. Treating your toilet as a trash can will cause sewer drain issues. In addition, never flush baby wipes! Even brands that claim to be flushable really aren’t. Click here to see what baby wipes can do to a municipal sewer pipe. As we always say, only three things should be flushed down the toilet – one of which is toilet paper. The other two come from you!

Pouring grease down the drain – Grease, fats and oil are all some of the biggest culprits when it comes to clogging lines. Never pour grease, oil, or other fats down a drain. Instead, pour hot grease into a coffee can or jar. Once it solidifies, you can throw it away. People mistakenly think that running hot water when pouring grease down a drain helps wash it away. This is not the case. Once grease cools off, it will harden and stick to your pipes, leading to sewer line clogs.

The grease that continues on its way eventually congeals further down the line with grease from numerous other households and commercial sources, causing formation of fatbergs in municipal sewers. Our blog post – “Still Pouring Grease Down the Sink? Don’t Do It!” – covers this topic in greater detail, and provides more information (and a photo) about fatbergs. 

The Take-Home Message

Proper overall care and maintenance of your plumbing can prevent many sewer line problems. Our blog post – “The Importance of Maintaining a Clean Sewer” – provides practical advice on steps to take and tips on troubleshooting.

Should you notice any of the trouble signs covered here, contact CarbonePlumbing. Our family-owned business has been serving Central Florida’s homes and businesses for over 60 years with reliable, dedicated service. Contact us to get – and keep – your home’s plumbing in top repair.

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