What is a Sewer Lateral: Inspection, Replacement, Cost

Last Updated On July 14, 2024

Updated on August 4, 2022



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What is a Sewer Lateral (2)

Do you want to learn more about your sewer lateral due to drainage issues? It can be difficult to gain access to your sewer line since a majority of it is underground. An inspection of your sewer lateral can provide some answers. 

But first, what is a sewer lateral? And who’s responsible for the cost: the property owner or the city?

In this PlumbingNav guide, we will cover:

  • What is a private sewer lateral line?
  • Common signs your sewer lateral needs replacement 
  • Lateral sewer line from house to street: who is responsible?
  • What is the average sewer lateral replacement cost?

What's In This Guide?

      What Is a Sewer Lateral Line?

      Your private sewer lateral line is the portion of your plumbing system on your private property that connects your private pipes to the city pipes. Most homes have a sewer lateral unless they use a private septic system. (Even still, a septic tank works similarly with a main line leaving the home and entering the tank.)

      Since the sewer lateral is a part of the city sewage system they require a compliance certificate. This will vary by city, so check with yours for exact specs.

      The lateral pipes tend to make up about half of your home’s sewer line along with your sewer main. The sewer lateral must have a proper slope for it to function properly and adhere to building codes. 

      There is some math involved! It’s important the right design and installation occur for proper water flow. This will also help you avoid a belly in the sewer line.

      Watch this video to see how slope is calculated for installing a sewer lateral:

      Proper sewer line cleaning can ensure a clean and sanitary system and prevent you from needing to replace the sewer line due to damage. Access will need to be done from the outside, near a cleanout.

      Common Signs Your Sewer Lateral Needs Replacement?


      If you have a leak in your sewer lateral, you may notice leaks that lead to puddles in your yard. The leaks often started much smaller but grew over time to the point where you notice them. Even small pinhole leaks can cause trouble for you, though. 

      Sewage Backup

      If you have a large enough clog, you may end up in a situation where you experience sewage backup in your home, causing a costly situation that also comes with health hazards. This can be an expensive problem that is sometimes unavoidable, but you can still prepare for it.

      Consider adding a rider for sewage backup to your home’s policy. Check with your homeowner’s insurance to cover plumbing issues like these. 

      Lateral Sewer Line From House to Street: Who is Responsible?

      What is a Lateral Sewer Line Inspection?

      A lateral sewer line inspection refers to an inspection of your lateral sewer line. 

      There are multiple sewer lateral inspection methods, including:

      • Building inspection 
      • Smoke inspection
      • Dye inspection
      • Mainline CCTV
      • Lateral CCTV
      • Pressure testing
      • Electro scanning

      Watch a professional inspection in action:

      Sewer Lateral Ordinance

      Keep in mind that the sewer lateral ordinance varies from city to city. Always check the laws in your area before proceeding with any work on your sewer lateral by checking government websites. This will also help define what you are responsible for, and what you are not.

      Sewer Lateral Replacement

      If your inspection finds a serious problem such as tree root intrusions requiring removal or deteriorating pipe sections, you may require sewer lateral replacement. 

      Today, we use trenchless sewer line replacement techniques to get the job done. 

      The two main methods of trenchless sewer line replacement include pipe bursting and pipe relining. Both methods are easier and cheaper than old methods that required plumbers to dig into the ground to gain access to the damaged pipe. 

      Pipe bursting is a method of replacing your sewer lateral by feeding a new pipe through the old one, taking the place of the host pipe. The old pipe dissolves into the soil after it bursts and the new pipe takes its place. Unfortunately, pipe bursting may not work on all older sewer pipe materials. It also won’t work if the damage is too extensive. 

      CIPP lining involves pouring an epoxy resin into a sock that lines the damaged pipe, and curing it with heat or light to make it hard. In most cases, the material won’t reduce the diameter of the pipe too much, although it may not be the best answer for very small pipes. It can also be difficult to cure the material if it’s too deep into the system.

      did you know what is a sewer lateral

      What is the Average Sewer Lateral Replacement Cost?

      While these methods we mentioned are cheaper than older ones that required digging, it still costs a significant amount of money. The cost depends on the length of the pipe you want to replace. 

      See the average prices for sewer lateral replacement:

      • Pipe bursting – $40 – $80 per foot
      • Sliplining – $80 – $170
      • CIPP – $25 – $65
      • Modified cross section – $18 – $50

      In most cases, CIPP is one of the best options as it’s the least expensive option and works in most situations. 

      Sewer Lateral Repair Program

      In many cases, the state or city may cover some or all of the cost of replacement if there are grant programs in place. We have seen this for water lines, and for cast iron or clay upgrades. Alternatively, they may be a sewer lateral program designed to contribute to the cost if you take on the responsibility. 

      Check with your city clerk or government websites to learn more about any programs you qualify for. Funding for these programs can be extensive or limited to a certain dollar amount per calendar year. At times, they exist for a multi-year window and then are closed. 

      The programs will not apply to you if your home uses a septic system. However, certain USDA grants do exist to encourage rural settlement. 

      FAQS on Private Sewer Laterals

      What is lateral connection for sewer?

      A lateral connection is where a property’s private sewer line connects to the public sewer line. 

      What is a lateral line in plumbing?

      Plumbing uses lateral lines to connect a private sewer system to the city sewer system. 

      What is a sewer lateral made of?

      A sewer lateral can be made out of a number of different plumbing materials. Generally speaking, older pipes consist of copper or cast iron while newer pipes consist of flexible plastic material. 

      What is a lateral cleanout?

      A lateral cleanout refers to an access point to your lateral line. Simply open the cover to the sewer cleanout to get direct access to a clog or any other problem. 

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      We write about “all things plumbing,” helping you navigate common questions, repairs, and the best plumbing products on the market.

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