Techniques and Technology of Trenchless Sewer Repair

No one enjoys spending time thinking about their sewer and wastewater system. For this reason, it can often come as an unpleasant surprise when you discover your drainage pipes have become cracked or broken. This means that you’ll need to immediately give your system some thought and attention.

The Sewer Systems Basics:

Residential homes are all equipped with a plumbing system that is designed to remove the wastewater from their homes either via a connection to a local municipality sewer system or a septic tank system. A main drain comes from your home to connect to either of these systems and is buried underground. If you’re connected to a municipal sewer system, the line typically runs from your property including across your yard and driveway down into the street. Unfortunately, this means that if there is damage to your sewer line, it can be a complicated issue to deal with.

What is Trenchless Repair?

In the past, if you had a broken or damaged sewer line, your only repair or replacement option was to have the line excavated. This meant having a large section of your yard and driveway dug up, with the hole remaining for days or even weeks. Fortunately, this is no longer the only option.

Trenchless repair was developed over 15 years ago and this technology has dramatically changed the techniques for repairing and replacing underground pipes and sewer lines.

As the name suggests, trenchless repair does not require a trench to be dug. This is a minimally invasive repair technique that only requires two holes to be made at either end of the affected section.

Trenchless repair does require state of the art equipment and innovative materials to repair broken sewer lines. Since it is less intrusive, the repair can be conducted more quickly and you won’t need to worry about rectifying the damage caused to your landscaping.

Signs You May Need Trenchless Repair:

If you’ve noticed some plumbing issues around your home, you may wonder if you have an issue with your sewer line. But there are more subtle signs that you need to be aware of. These include:

  • Consistent blockages and backups: If you have a blocked drain, it can be annoying, but when there are consistent blockages in different drains around your home, it is a sign that you have an issue with a misaligned or cracked pipe. Indications include bubbling or gurgling, slow draining water and water backing up in your sink, bathtub, or toilet could suggest that you have an issue that needs investigating.
  • Bad smells in your yard: If you’re trying to enjoy your outdoor space, but keep getting a sewer like odor, it could indicate that your sewer line has been cracked or damaged. Sewer lines are designed to be airtight, apart from the venting which creates the pressure to move the sewage downwards.
  • Swampy areas in your yard: Another outdoor sign of a sewer line problem is if there are marshy or swampy areas in your yard. If you can see water or sewage pooling, it could suggest that sewage is leaking from the line under this part of your yard.
  • Landscaping changes: You may have also noticed that your landscaping has started to change. If you have areas of your landscaping that appear unusually luscious, it could be due to an underground sewer line leak. The sewage may be acting as an additional fertilizer and providing extra nutrients to the plants and grass in the exposed area.

Common Trenchless Repair Methods:

The term “trenchless repair” actually involves a number of techniques. These include:

  • Pipe bursting: This is the easiest form of trenchless sewer replacement with specialist training. The technique involves breaking the existing pipe by expanding it as a new high density polyethylene pipe is put into place to simultaneously replace the damaged section. The contractor will insert a head into the old pipe, which will fracture the pipe as the new pipe is dragged and laid down behind it.
  • Slip lining: This is a form of trenchless rehabilitation which involves adding an epoxy liner to the existing pipe. This will create a pipe inside a pipe without the need to completely remove the initial pipe.
  • Cured in place lining: This is a more complicated method, which is also known as CIPP. A resin saturated pipe liner is placed inside the damaged pipe, which then expands in place and will be cured as heat is applied.
  • Spray lining: This is similar to a structural pipe lining, but a flexible polymer is sprayed into the damaged section of pipe.

Which Method Should I Choose?

With so many technologies and techniques, it may seem difficult to choose which one is most appropriate for your project. There are a number of factors you’ll need to consider to make an informed decision.

  • Reduced Water Flow: It is important to note that both CIPP and slip lining involve creating a new pipe within the existing line. This will reduce the internal diameter of the pipe. So, if you already have low water pressure and issues with water flow, you may need to consider other methods.
  • Lifespan: The pipe bursting technique involves using high quality HDPE materials. This type of pipe has an expected lifespan of 100 years or more. So, if you have concerns about needing to replace the pipes again in your forever home, you may want to consider this long lasting product. 
  • Environmental Impact: If you are concerned about your yard being exposed to chemicals or potential contaminants, you may need to think about which technique is best. Studies have documented that some CIPP installations release styrene during installation. This is a hazardous chemical that may end up in stormwater and your soil.

There are some scenarios where some trenchless techniques may not be possible. So, it is important to consult an experienced, professional plumbing contractor. Your contractor will be able to guide you through the impact of the various techniques and technologies to help you make an informed decision.