What is considered a sewer line?

Author: Mr. Jaiden Breitenberg  |  Last update: Sunday, June 14, 2026

What Is a Sewer Line? If your home is connected to a sewer system, there is a sewer line that bridges the gap between your home's drains and the main sewer drain. This line is located under the ground of your yard and is considered part of your plumbing system and your responsibility for maintenance and repairs.

What is considered the main sewer line?

What is a Main Line? To put it simply, your main line is your sewer line. It's a line located underground that carries all wastewater from your home to a municipal connection or septic tank, not just toilet water.

What are the three types of sewer lines?

There are three main types of sewer systems: Sanitary sewers, stormwater sewers and combined sewers. Some households are attached to septic systems, but these systems do not attach to offsite sewer systems.

Is there a sewer line on my property?

Most of the time, the sewer line will be sticking out of the ground and easy to spot; however, overgrown landscaping or objects close to the house could hide the cap. Or, you could have a buried sewer cleanout. Try searching on the side of the home that is closest to the main floor bathroom.

What is the difference between a drain line and a sewer line?

What is the Difference Between a Main Drain and a Sewer Line? While both main drains and sewer lines transport wastewater away from your home, there are critical differences between the two systems. Main drains are located in the walls and floors of your home, while sewer line drains are located outside underground.

A House Sewer Line Has 3 Types: Learn About Sewer Lines

Does a kitchen sink drain to a sewer line?

The drainpipe from your kitchen sink connects to the larger sewer line or wastewater plumbing system of your house.

Is a sewer line considered plumbing?

If your home is connected to a sewer system, there is a sewer line that bridges the gap between your home's drains and the main sewer drain. This line is located under the ground of your yard and is considered part of your plumbing system and your responsibility for maintenance and repairs.

How do I locate my sewer line?

Go to the city office directly or call them to see if they can tell you where the sewer line is located. Usually, they can show you where the line goes from your home to the city's main line. If you are unable to reach the city, see if there is an interactive underground utility map of your area online.

Does homeowners insurance cover sewer lines?

In most cases, home insurance will cover sewer line damage from specific events. This includes extreme weather (excluding earthquakes and floods), vandalism, fire, and damage from vehicles or falling objects.

How much does it cost to fix a clogged sewer line?

You will likely pay around $350 to $650 to have a plumber unclog a main sewer line unless you have complications like serious damage to the line.

What does a sewer line look like?

You may spot a 3 to 4-inch diameter pipe peeking out of the slab floor of the basement. The sewer drain pipe could be made of plastic or cast iron; it might be copper or brass in rare cases. The stub-out will have a screw-in plug coupled with a square-head lug on it, representing your access to the main drain.

How many sewer lines does a house have?

Not in most homes. Ordinarily, you have one sewer line that is intended to primarily carry what's known as “black” water; water from the toilets into either the city sanitary sewer system or into your own septic tank.

How deep are sewer lines buried?

For instance, residential sewer line depth ranges from 18 to 30 inches. However, city sewer line depths are different. Your city's sewer lines must always be deeper than the deepest residential pipe to allow waste to flow downhill. As such, these lines can go as deep as needed.

Where do sewer lines usually run?

A house sewer runs underground from the street to the house. Typically your main drain pipe is either 4″ or 6″ inches in diameter. The house drain inside your home is connected to your house sewer pipe at the front wall of your building.

What size is a residential main sewer line?

Depending on your local plumbing codes, the main sewer line for residential homes is usually 4 inches in diameter. You may think if the pipe were larger, more waste could travel without getting clogged.

How many drain lines does a house have?

A standard home will usually only have one main drain that leads to the public drainage system.

How many years does a sewer line last?

Generally speaking, you're going to find that most main sewer lines will only last somewhere between 50 and 100 years before you need to do a main sewer line replacement. You could very well have a broken sewer line on your hands right now and not even realize it.

How much is sewer line insurance?

Sewer line coverage varies in cost but can generally be obtained for $5 to $15 per month, depending on your property size and the area in which you live. Because sewer line incidents often cost upwards of $10,000 to repair, many homeowners consider sewer line coverage a good investment.

Are local governments responsible for paying for sewer line repairs?

Sewer laterals are the underground pipes that connect your home wastewater to the main sewer line in the street. Homeowners are responsible for their sewer laterals, while problems with the public sewer main line are managed by the city or municipality.

How do I know if my property is connected to a sewer?

Deeds: Property deeds may detail sewer line agreements. Look for any references to shared infrastructure or easements. Sewer Maps: Local planning offices or utility companies keep sewer maps showing the layout of sewer lines.

What is the difference between a sewer line and a drain line?

The main sewer line is outside the home, while drain lines are inside your house. When these systems need maintenance or repairs, the type of plumber you should call will depend on whether the problem is in a drain line inside your home or the main sewer line outside your home.

Do all houses have a sewer cleanout?

A lot of people think they don't have sewer cleanouts. But as I said, pretty much all homes do these days. It's more likely that your sewer cleanout is buried, often in a flower bed area. People cover up the cleanout because they think it's an eyesore.

Do plumbers check sewer lines?

Professional plumbers can use various camera styles to inspect the sewer line, such as: Remote-controlled crawler cameras. Pole or fixed zoom cameras. Push rod cameras.

Who pays for sewage backup?

Every year, sewer backups cause damage to millions of households. Many homeowners may not know that they tend to be responsible for the maintenance and repair of the pipeline between their city's sewer main and their building, and if it gets damaged or clogged, it's financially their responsibility to remedy the issue.

Is the sewer line the main line?

Simply put, your mainline is your sewer line. And all your drains connect to your main line. Your main line is also the line that goes from your house to the city connection or your septic tank. Before leaving your home, all of your drains dump into your mainline.

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