When you buy a house on a public sewer, you usually buy its side sewer too: the buried pipe from the house to the public main. In Seattle, Seattle Public Utilities (SPU) says the owner owns that pipe all the way to the main under the street, and the owner pays to fix it. A sewer camera inspection (“sewer scope”) before you close tells you what you are taking on.
Washington’s state plumbing code does not adopt the provisions affecting sewers (RCW 19.27.031), so who owns which part of the pipe is set by each city or sewer district. The Seattle rules below are an example; outside Seattle, ask the sewer utility where an owner’s responsibility ends.
Why scope before you buy
- SPU recommends it. Its maintenance guidance says: “Have the side sewer inspected before you purchase a property.”
- It’s the buyer’s pipe afterwards. In Seattle the side sewer includes all piping outside the building footprint up to, but not including, the connection to the public main, according to SPU’s permit page. Problems found after closing are the new owner’s.
- The seller disclosure has limits. Washington’s seller disclosure form (RCW 64.06.020) asks whether the house is connected to the sewer main, but it is based on the seller’s actual knowledge. The form itself advises buyers to hire qualified experts, including plumbers, to inspect the property.
- SPU also recommends regular scoping at least every 8 to 10 years, and every 2 to 3 years where large trees or shrubs grow near the line.
What the inspector should deliver
Agree on these before the inspection:
- The video file, on a USB drive or as a download link. SPU says most contractors can provide one, and a copy is useful if you later file a claim with the city or want to see whether the pipe is getting worse.
- A written report listing each defect and its distance, in feet, from the access point. SPU recommends having the location written down and the spot marked on the ground, because it helps decide whether a problem is on your side of the connection and where to dig.
- Pipe materials along the run, and any changes in material.
- Whether the camera reached the public main. A scope that stops short leaves part of the pipe unseen. SPU tells owners to check that a rooter’s cable can reach from the side sewer to the main, typically under the street or alley.
- Whether the line had to be cleared first. SPU says cameras cannot see under water, so a blocked line must be cleared before it can be inspected.
In Seattle, SPU will review a scope video where the connection to the main may be damaged, and can help establish whether a repair is the owner’s or the city’s.
Common findings
SPU’s defects page grades common problems as minor, moderate or severe. Its recommendations:
| Finding | What it is | SPU’s recommendation |
|---|---|---|
| Roots | Roots enter through cracks and joints; older concrete and clay pipe without watertight joints is especially at risk | Minor or moderate: re-inspect in three to five years. Severe (blocking 50% or more): routine cleaning and inspection every one to two years |
| Offset joints | Pipe segments that don’t line up | Minor: no repair. Moderate: re-inspect after a few years. Severe: repair, because soil can wash in and leave voids |
| Sags (bellies) | A section with no slope; side sewers are built to fall about ¼ inch per foot | Under 25% of the diameter: minor. 25–50%: re-inspect every two to five years. 50% or more: repair |
| Cracks and fractures | Breaks from poor installation or bedding, roots or age | Moderate: re-inspect every one to two years and plan for repair if worsening. Severe: repair |
| Holes | Can let soil wash away and leave a void | Repair |
| Exposed aggregate | The inside of concrete pipe wearing away to the stones | Moderate: plan for repairs. Severe with holes: replace as soon as found |
| Debris and grease | Build-up that slows or blocks flow | Routine cleaning; structural repair if a defect is contributing |
Orangeburg pipe. Bituminous fiber pipe, sold as “Orangeburg,” was made from plant fibers and asbestos soaked in a tar-like binder. The City of Ann Arbor, Michigan, says bituminous fiber systems have had numerous failures, and that most of its local sewer pipe failures over about twenty years involved this material. It puts local installations at roughly the early 1950s to the early 1970s. As it deteriorates it flattens under soil pressure, and the city says all or part of it may need replacing. A camera may show damage patterns that help identify it. We found no Washington source on how common it is here.
Clay and concrete pipe. SPU says many Seattle side sewers are concrete, and it singles out older concrete and clay pipe without watertight joints as most at risk from roots.
Who should do the scope
SPU says you can hire a plumber, a drain rooting service or a sewer inspector, and that any licensed plumber or rooting service can scope a side sewer. In Washington, the L&I drain cleaning specialty (RK) covers camera examination of sewer pipe (WAC 296-200A-016). Check the company on L&I’s Verify tool.
If possible, hire someone who isn’t bidding for the repair. A company that scopes and repairs may be perfectly honest, but you are then relying on the contractor who would do the work to judge whether it is needed. Either way, get the video, so other contractors can quote on the same footage. You can find camera providers under sewer camera inspection and in our drain cleaning and sewer camera directory.
Indicative cost
SPU’s Taking Care of Your Sewer Pipe flyer (file modified April 2026) says a sewer video inspection “generally costs $230 - $845, depending on your pipe’s condition.” This is an SPU figure for Seattle, not a quote. The same flyer suggests checking with at least three companies to compare costs.
For what repairs might cost if the scope finds a problem, SPU’s per-foot figures for lining, bursting and other methods are in our guide to side sewer replacement.
Using the results in negotiation
A scope gives you facts to take back to the seller before your inspection deadline:
- Get repair bids on the same video. SPU recommends at least three written bids for side sewer repairs, and says contractors may recommend different methods. Bids based on the same footage are easier to compare and harder to dispute.
- Separate “repair now” from “watch.” SPU’s grading treats many minor and moderate findings as reasons to re-inspect, not to repair. A credit request is stronger when it rests on defects SPU says should be repaired or replaced.
- Ask what is already known. Ask the seller for past scope videos, repair invoices and permits. In Seattle, SPU can tell you whether it has inspection video of the connection to the main.
- Talk to your broker about how your purchase agreement’s inspection terms work and what you can ask for.
Questions to ask the inspector
- Will you run the camera all the way to the public main? What happens if you can’t?
- Will the line need clearing first, and is that included in the price?
- Will I get the full video file and a written report with footage marks?
- Will you identify the pipe materials and any changes along the run?
- Will you mark the location of major defects on the ground?
- Do you also do repairs? If so, will you put the findings in writing so another contractor can bid?