Sewer line work is the scariest quote in home ownership, so here are the honest ranges: spot repairs run $3,000–$7,000, full replacement of a residential side sewer runs $8,000–$25,000, and complicated urban jobs (deep lines, street cuts, shared side sewers) can exceed $30,000. The spread is wide because the driver isn’t pipe — it’s access, depth, and permits.
Cost by method
| Method | Best for | Typical cost (wet side) |
|---|---|---|
| Spot repair (excavated) | One bad section, shallow line | $3,000–$7,000 |
| Pipe lining (CIPP) | Structurally intact pipe with cracks/root intrusion | $90–$250 per foot |
| Pipe bursting (trenchless) | Full replacement without trenching the yard | $100–$300 per foot |
| Open-trench replacement | Collapsed or back-pitched lines | $50–$250 per foot + restoration |
A typical wet-side side sewer is 50–100 feet, which is how per-foot prices become five-figure totals. Trenchless methods cost more per foot but often win overall once you price yard, driveway, or sidewalk restoration that trenching destroys.
The wet-side wrinkle: you own more pipe than you think
In most Western Washington jurisdictions — Seattle very much included — the homeowner owns and maintains the entire side sewer, from the house to the connection at the city main, including the section under the public street. A collapse under the road is your bill, plus street-cut permits and pavement restoration. This surprises nearly everyone, and it’s why identical-sounding jobs can differ by $15,000.
Seattle-specific notes:
- Side sewer work in Seattle requires a side sewer permit and a registered side sewer contractor.
- Much of Seattle’s older housing stock still drains through concrete or clay pipe from the 1900s–1950s, and neighborhoods built mid-century have a known belt of failing Orangeburg (bituminous fiber) pipe. If your home is pre-1960 and the line has never been replaced, budget for the conversation.
- Street trees are beautiful root-delivery systems. Roots at the joints are the wet side’s most common failure mode — our shallow, wet soils make it easy for them.
Repair, line, or replace?
The only honest answer comes from a camera inspection ($150–$500, often credited toward work). The decision logic most good contractors follow:
- Roots at a few joints, pipe otherwise sound → hydro jetting plus spot repair or lining.
- Cracks along the run, pipe still round → lining (CIPP) preserves the pipe as a host.
- Collapsed, back-pitched, or Orangeburg → replacement; lining can’t fix geometry, and Orangeburg has no structure left to line.
Get the camera footage itself, not just a verbal summary. A contractor who won’t hand over the video is asking you to buy a five-figure job on trust.
Keeping the quote honest
- Insist on per-foot pricing plus itemized permits and restoration, not one bundled number.
- Verify licensing at lni.wa.gov; in Seattle, ask for the side sewer contractor registration specifically.
- For jobs over $10,000, a second camera-verified opinion routinely pays for itself.
- Ask whether the quote includes city-main connection fees and street restoration if the line crosses public right-of-way.