Your sewer lateral: what it is, who owns it, and who pays to fix it
Updated
The short answer
A sewer lateral is the pipe that carries wastewater from your house to the public sewer main, usually under the street. In most US cities the homeowner owns and maintains the whole lateral, including the section under the sidewalk and street and the connection at the main. Some cities take over at the property line or the curb, so check yours.
How urgent · It depends
Not urgent until something breaks — but it decides who pays when it does. Check your city's rule before you need it, and before you buy a protection plan or a house.
What a sewer lateral is
Inside the house, drains join into a main building drain. Where that pipe leaves the foundation it becomes the building sewer, more often called the sewer lateral or service line, and it runs underground to a connection — a wye or tap — on the public sewer main.
A residential lateral is typically 4 to 6 inches across and anywhere from about 15 to over 100 feet long, depending on how far the house sits from the main. It usually has at least one cleanout, a capped access pipe near the house or the property line. Some cities divide it into an upper lateral, from the house to the property line or cleanout, and a lower lateral, from there to the main.
Who owns which part
There's no national rule. Responsibility is set by each city or sewer district, and the differences matter by thousands of dollars. These examples show the range.
| Where | The rule |
|---|---|
| Los Angeles County Public Works | Owners maintain the lateral, including the portion beneath the sidewalk and street and the point where it joins the public main. |
| New York City | Owners are responsible for the private service line to the city's main. DEP inspects the main within six hours of a backup report and issues a notice to repair if the fault is private. |
| St. Louis | Owners own the lateral, but a $28 annual fee on residential property taxes (6 units or fewer) funds city repair of severe breaks under the public right of way. Clogs and roots aren't covered anywhere on the line. |
| Chattanooga | The city council transferred responsibility for laterals under the city right of way from homeowners to the city. |
| East Bay cities, California (EBMUD) | Owners must obtain a lateral compliance certificate — a camera inspection and a witnessed leak test — when selling, remodeling over $100,000, or changing water meter size. |
Examples from each authority's published guidance as of 2026. Rules change; confirm with your own utility.
How to find your city's rule
- Search for your city or sewer district name with 'sewer lateral responsibility' — most publish a page or a diagram.
- If it's unclear, call the public works department or sewer utility and ask where the owner's responsibility ends: the house, the cleanout, the property line, the curb or the main.
- Ask who repairs the connection at the main, and whether a street-cut permit or approved contractor is required.
- Ask whether the city runs a repair, reimbursement or low-interest loan programme for laterals.
- Ask whether a lateral inspection is required when you sell or remodel.
- Save the page or get the answer in writing, so you can show it to a contractor or an insurer later.
Clogs versus breaks, and proving where the fault is
Even where a city repairs the section under its right of way, keeping the line clear is almost always the owner's job. Clogs, grease and roots are treated as maintenance anywhere along the lateral.
When there's a dispute about where a problem is, the burden usually falls on the owner to show it. In practice that means paying a plumber for a camera inspection with a locate, showing the defect's distance and position relative to the property line. Many city programmes, including St. Louis's, ask for exactly that footage before they'll act.
Why the section under the street costs so much
Repairing a lateral under a public street isn't just more digging. It usually needs a right-of-way or street-cut permit, traffic control, saw-cutting and replacing pavement to city standards, sometimes a sidewalk and curb, and work at the connection to a main that may be deep. That combination can add roughly $3,000 to $15,000 or more to a repair, which is why a city's responsibility rule can matter more than the pipe itself.
Buying or selling a house
If your city has a point-of-sale lateral ordinance, the certificate is part of the sale, and a failed test has to be fixed before or as a condition of transfer. Even where there's no ordinance, buyers of older homes increasingly order a sewer scope, so sellers may as well know first.
Buyers should ask for any existing camera footage, permits for past lateral work, and whether the line is shared with a neighbour — older neighbourhoods and some attached housing have shared laterals, where responsibility is set by an easement, a deed or an association rather than the city.
Paying for your part
Once you know which section is yours, the options are a service line add-on on your homeowners policy, a utility-branded protection plan, a city programme if one exists, or budgeting for it. Check that whichever you choose actually covers the section your city makes you responsible for.
Frequently asked questions
- What is a sewer lateral?
- The underground pipe that carries wastewater from your house to the public sewer main. It's also called the building sewer, sewer service line or house connection.
- Who is responsible for the sewer line from the house to the street?
- In most US cities, the homeowner — often all the way to and including the connection at the main under the street. Some cities take over at the property line or curb, and a few repair the right-of-way section themselves. Check your city's published rule.
- Is the city responsible for the sewer line under the street?
- It depends on the city. Many hold the owner responsible for the lateral even under the street; others, such as Chattanooga, have taken over that section, and St. Louis repairs severe breaks there through a small annual fee.
- What is the difference between an upper and lower lateral?
- Where cities use the terms, the upper lateral runs from the house to the property line or cleanout, and the lower lateral runs from there to the public main. Some cities split responsibility at that point.
- Who pays if roots from a city tree damage my sewer lateral?
- In many cities the owner still pays, because the lateral is theirs. Some cities accept responsibility for damage from city trees or for the right-of-way section. Ask your public works department.
- Do I need a permit to repair my sewer lateral?
- Almost always. Private-property work needs a plumbing or sewer permit and inspection, and anything in the sidewalk or street needs a right-of-way permit, often with city-approved contractors.
- What is a sewer lateral inspection?
- A camera inspection of the lateral, sometimes combined with a pressure or leak test. Some cities require one — with a compliance certificate — when a property is sold or substantially remodeled.