According to the Environmental Protection Agency (EPA) roughly 80% of households are connected to the city sewer system (the remaining one in five have their own private or shared septic tank). For each of this 80% connected to the public sewer system, their home is connected to the mains by a series of pipes.
These pipes are known as a sewer lateral. Put simply, the sewer lateral is what connects your home’s bathrooms and other outputs to the city’s sewer system. They usually run below your home, under your yard, and onto the street, where they connect to the larger communal pipe.
There’s a strong chance you don’t think about the sewer lateral under your property. However, you should know: about how it works, what are some common problems, and who is responsible for maintenance.
Sewer laterals are one of the primary causes of basement flooding. Not only is this usually unpleasant, but it can also end up costing you thousands of dollars. This guide will walk you through a variety of different permutations relating to your sewer lateral. For more information about the costs of repair, see our guide on the average cost of sewer laterals.
WHAT IS A
The phrase ‘sewer lateral’ refers to the pipe connecting your home’s plumbing to the city-owned sewer line. Usually a sewer lateral runs from immediately under your house to the street, where it connects with the publicly-owned line.
Depending on your city’s ordinances, the boundary between private sewer lateral and the city sewer lies either at your property line (in most places) or at the edge of your yard.
THERE ARE TWO KEY PARTS TO A SEWER LATERAL – UPPER AND LOWER:
Upper Sewer Lateral
The upper part is the part nearest to your home. This includes everything from where the pipes leave your home (the building cleanout) to the sidewalk. Most of this part of the pipe runs underneath your yard, with the exception of the part that runs underneath the foundation of your home.
Lower Sewer Lateral
The lower lateral is from the sidewalk to where the pipe meets the publicly-owned main. This part is usually embedded under the public road.
WHO OWNS A
Intuitively, because the sewer lateral connects to the public utility, it is tempting to think of it as the city’s property. However, in general, a sewer lateral is part of your property, meaning that the homeowners own it. A better way to think of it is like the wiring in your home. If the wiring is in your property, it’s not the city’s responsibility to fix. The same is true of the sewer lines.
A key issue when it comes to sewer laterals is that of easement – namely the right to access private property. With sewer laterals, because the sewer feeds into the public utilities, the city retains some rights over the sewer as it lies on your property.
There are some distinctions made between the upper and lower laterals as to ownership, but in general, if the pipe is on your land, then you own it. This naturally has consequences when it comes to responsibility.
Really the only time that ownership of a sewer lateral becomes important is when something breaks. At this time, there are very clear rules on who owns the laterals, and therefore who is responsible for it being fixed.
The first thing to ascertain is precisely where the problem is. If you identify that, you can tell who is in charge of fixing it – and therefore who has to foot the bill. Generally, the answer will be either you (the homeowner) or the city.
Line of Demarcation
You will need to check your city’s ordinances to find out where the boundary lies according to your local rules.
The majority of cities’ rules give ownership (and therefore responsibility) for the lower and upper laterals to the homeowner.
However, in some cities, such as Berkeley, CA, the lower sewer lateral is publicly owned, meaning that, if the road needs to be dug up, it is the city that will have to pay for it.
Along with paying for any necessary repairs, there are also environmental responsibilities that homeowners have for their sewer lateral. Because it empties into the public main, environmental concerns are of critical importance and are the responsibility of the homeowner to avoid contaminating the public supply.
There are two main concerns when it comes to environmental risks of broken laterals:
As a result of both of these, the EPA requires all private sewer laterals to be properly certified. This certification is managed through local authorities, so be sure to check your local ordinances to see how this process takes place.
Exfiltration failures are when fluid from inside the sewage pipe leaks out. This can be extremely dangerous because of the biohazards present in sewage. Exfiltration failures can cause contamination of the water supply.
An inflow (or infiltration) failure is when water from outside of the pipe leaks in. This is most commonly caused by excess rainwater or groundwater forcing its way into the sewer lateral.
The problem in this instance is that it can cause the sewage pipes to become overwhelmed and cause sewage backups in a number of places. In some instances, it can even cause sewage to pollute bodies of water such as lakes or the ocean.
As a result, you not only have a financial interest in ensuring the adequate maintenance of your sewer laterals, but also an environmental – not to mention ethical – interest.
HOW TO DIAGNOSE
A SEWER LATERAL PROBLEM
If you suspect a problem with your sewer lateral, you can use some of the following common diagnostic tools.
IN YOUR HOME
If the water level in your toilets fluctuates, it could be due to problems with your sewage line. If your plumbing has suddenly started making new sounds or smells, then it is definitely time to call a plumber.
Mold is also linked with sewage problems, although, because mold has a number of other causes, it’s best to only call a plumber if you have the other signs of sewage problems listed.
IN YOUR YARD
In your yard, the most common signs of a broken sewer line are excess sogginess at any point. This will usually be followed by the smell of sewage – meaning you should be able to notice it fairly quickly.
In some cases, your grass may be greener than it was previously (or a small patch of grass is noticeably greener). In this case, your sewage is fertilizing the grass; again, there may also be an accompanying smell.
A video inspection will require a professional to provide the equipment and the expertise. In this case, a plumber will run a video down the line of your sewer, which will be able to identify blockages as well as see if tree roots have entered the pipe.
The majority of problems with a sewer lateral are the result of a small number of causes. If you notice any of the above signs of sewage problems, then the chances are, it’s the result of one of the below.
If sewer lateral pipes are old, they are far more likely to experience leaks. Modern pipes are made of robust plastic, although some older models are made of metals that can corrode, or perish at the joints.
If your pipes have corroded, then you may need to replace them in their entirety.
If the soil shifts around your property, then it can cause pressure on the sewer lateral. Soil can shift for a number of reasons, whether via hydrostatic pressure from rain or flooding, to periods of drought, to freezing temperatures, or even earthquakes.
In any of those cases, the sideways pressure on the sewer lateral may cause a small leak or crack. In some cases, this can take many months to be noticeable, although once there is a leak it will almost certainly get bigger.
Tree roots are a major problem because of the force they exert while growing. They can very comfortably grow through sewer laterals. If they do, they can cause leaks or blockages, both of which are extremely bad for pipes, as well as for the property it is leaking or backing up into.
If you have tree roots in your sewer lateral, removing them can be a very large undertaking, whether by dissolving or cutting out the roots.
Ultimately, a sewage system is not usually the first thing you think of when it comes to home maintenance.
Not only does it deal with fairly unpleasant material, but it lies out of sight below your property. The only time that the sewer lateral crosses your mind is when something goes wrong.
However, the sewage system connecting our home to the city’s main is a really visceral representation of how we operate as part of a community.