Short answer

Repeated backups in several drains, sewage smells outside, soggy patches in the yard or drains that gurgle across the house usually point to a problem in the main sewer line. The right repair depends on what a camera inspection shows: roots and buildup can often be cleaned, while broken, collapsed or badly sagging pipe needs a spot repair, lining or replacement.

Where your sewer line runs

Every drain in your home feeds into a main building drain under the house. That leaves the foundation and becomes the sewer lateral, which runs under the yard to the city's sewer main, often near the street or an alley. Somewhere along it, usually just outside the house, there should be a cleanout: a capped pipe that gives a plumber access to the line.

Warning signs of a sewer line problem

  • Several drains backing up or slow at once, especially the lowest fixtures such as a ground-floor shower
  • Water coming up in the tub or shower when you flush a toilet or run the washing machine
  • Gurgling from toilets and drains across the house
  • Sewage smell indoors near floor drains, or outside in the yard
  • Unusually green or soggy patches of lawn along the line's route, or a depression forming in the yard
  • Clogs that come back soon after the main line has been cleared

If sewage is coming up into the house now, stop running water and read drain backing up and sewer line problems.

What goes wrong with sewer lines

  • Tree roots. Roots seek out moisture and nutrients and can enter through joints or small cracks, then grow into a mat that catches waste.
  • Bellies or sags. A section of pipe settles lower than the rest, so waste and water pool there and build up. Soil movement is a common cause.
  • Offset or separated joints, where two sections of pipe have shifted out of line.
  • Cracks, breaks and collapse, especially in older pipe materials.
  • Grease and debris buildup over years of use.
How a house connects to the city sewerDrain lines under the slab join the building drain, which passes a cleanout near the foundation and continues as the sewer lateral to the city sewer main under the street. Common trouble spots on the lateral are root intrusion, a sagging section called a belly, and offset or cracked joints.Street123CleanoutBuilding drainCity sewer mainSewer lateral1Tree roots entering joints2Belly: a sagging section that holds water3Offset or cracked joint
Common trouble spots between the house and the sewer main. Who owns each section of the lateral varies, so confirm with City Engineering (972-547-7420).

How a plumber diagnoses it

A sewer camera inspection is the key step. The plumber feeds a camera on a flexible cable through the cleanout and records the inside of the line, noting the distance to any problem. Many cameras also have a locator so the plumber can mark the exact spot on the ground above. Ask for a copy of the video. It lets you get a second opinion and compare quotes on the same information.

Sometimes the line needs to be cleared with a cable machine or jetter before the camera can see clearly. See drain cleaning.

Repair options

Cleaning only

If the camera shows roots or buildup but the pipe is structurally sound, cleaning may be enough, perhaps with a plan to recheck. It will not fix a crack, belly or offset.

Spot repair

A single damaged section is dug up and replaced. This works well when the problem is in one place and not too deep or under something expensive, like a driveway.

Trenchless lining (cured-in-place pipe)

A resin-soaked liner is pulled into the old pipe and cured, creating a new pipe inside the old one without digging a trench along the whole route. It suits cracked or root-damaged pipe that still holds its shape. It is not suitable for a collapsed pipe or a serious belly, because the liner follows the existing shape.

Pipe bursting

A new pipe is pulled through the old one while a bursting head breaks the old pipe outward. It needs access pits at each end rather than a full trench.

Full replacement by excavation

The old line is dug out and replaced. This is the most disruptive option, but it fixes grade problems like bellies properly and is sometimes the only option.

Before any digging

  • Anyone digging needs to have underground utilities located. Texas uses 811 (DIGTESS). The City of McKinney's FAQ says to call 811 or 1-800-DIGTESS at least 48 hours before digging 16 inches or deeper, and to contact Building Inspections before digging deeper than 6 inches. See the city's FAQ.
  • Sewer replacement work generally needs a permit. Ask the plumber whether they will pull it and arrange the inspection.
  • Ask where the line connects to the city main, and who is responsible for which section. McKinney's FAQ suggests calling the Engineering department at 972-547-7420 with questions about responsibilities, and Public Works at 972-547-7360 for help locating a cleanout.

What to ask a plumber

  • Can I have the camera footage, with the problem locations and depths marked?
  • Is cleaning enough, or is there a structural defect?
  • Is trenchless an option for my line, and if not, why not?
  • Does the quote include the permit, restoration of lawn, landscaping or concrete, and a warranty?
  • What happens if you find more damage once the line is open?

Check the license on the TSBPE lookup before signing anything. Master plumber license numbers start with "M".

What affects the cost

The biggest factors are the repair method, the length and depth of the line, what sits on top of it (grass, driveway, patio, trees), the number of problem areas, and how much surface restoration is included. Getting two or three quotes based on the same camera footage is the fairest way to compare.

Frequently asked questions

Who is responsible for the sewer line between my house and the street?

Responsibility for the lateral can depend on where the problem is and on local rules. Rather than rely on a general answer, contact the City of McKinney Engineering department at 972-547-7420, which the city lists for questions about responsibilities.

How do I know if roots are in my sewer line?

Repeated main line clogs, gurgling and slow drains across the house are common signs, especially with large trees near the line. A camera inspection confirms it, and a plumber clearing the line with a cable machine will often pull back visible roots.

Is trenchless sewer repair always cheaper?

Not always. Trenchless methods avoid digging a long trench, which saves a lot when the line runs under driveways or landscaping, but the equipment and materials cost more. For a short, shallow line in open lawn, digging can be competitive.

Should I get a sewer inspection when buying a house?

It is a good idea, particularly for older homes or houses with large trees in the yard. Standard home inspections usually do not include a camera inspection of the sewer line.

Does homeowners insurance cover sewer line repair?

Coverage varies widely. Many standard policies exclude wear, tree roots and gradual deterioration, and some insurers offer a separate service line endorsement. Check your policy or ask your agent before the work starts.